WorldWideScience

Sample records for receptor homologue m33

  1. Partial functional complementation between human and mouse cytomegalovirus chemokine receptor homologues

    DEFF Research Database (Denmark)

    Farrell, Helen E; Abraham, Alexander M; Cardin, Rhonda D

    2011-01-01

    The human cytomegalovirus (CMV) proteins US28 and UL33 are homologous to chemokine receptors (CKRs). Knockout of the mouse CMV M33 protein (UL33 homologue) results in substantial attenuation of salivary gland infection/replication and reduced efficiency of reactivation from tissue explants. M33......-mediated G protein-coupled signaling is critical for the salivary gland phenotype. In this report, we demonstrate that US28 and (to a lesser degree) UL33 restore reactivation from tissue explants and partially restore replication in salivary glands (compared to a signaling-deficient M33 mutant...

  2. Identification of common mechanisms by which human and mouse cytomegalovirus seven-transmembrane receptor homologues contribute to in vivo phenotypes in a mouse model

    DEFF Research Database (Denmark)

    Farrell, Helen E; Abraham, Alexander M; Cardin, Rhonda D

    2013-01-01

    The mouse cytomegalovirus chemokine receptor homologue (CKR) M33 is required for salivary gland tropism and efficient reactivation from latency, phenotypes partially rescued by the human cytomegalovirus CKR US28. Herein, we demonstrate that complementation of salivary gland tropism is mediated...... predominantly by G protein-dependent signaling conserved with that of M33; in contrast, both G protein-dependent and -independent pathways contribute to the latency phenotypes. A novel M33-dependent replication phenotype in cultured bone marrow macrophages is also described....

  3. Histamine homologues discriminating between two functional H3 receptor assays. Evidence for H3 receptor heterogeneity?.

    Science.gov (United States)

    Leurs, R; Kathmann, M; Vollinga, R C; Menge, W M; Schlicker, E; Timmerman, H

    1996-03-01

    We studied several histamine homologues as potential ligands for the histamine H3 receptor in two binding assays ([125l]iodophenpropit and N alpha-[3H]methylhistamine binding to rat brain cortex membranes) and two functional H3 receptor models (inhibition of the neurogenic contraction in the guinea pig jejunum and of [3H]noradrenaline release in mouse brain cortex slices). The histamine homologues acted all as competitive H3 antagonists at the guinea pig jejunum. The potency in this model and/or the affinity for N alpha-[3H]methylhistamine binding was higher for the butylene (pA2 = 7.7; pKi = 9.4) and pentylene homologue (impentamine, pA2 = 8.4; pKi = 9.1) than for the propylene, hexylene and octylene homologues (pA2 = 5.9-7.8; pKi = 6.1-7.6). In the mouse brain cortex the propylene, butylene and pentylene homologues acted as partial agonists (alpha = 0.3-0.6) and the hexylene and octylene homologues acted as antagonists. [125I]Iodophenpropit binding was displaced monophasically by the propylene, hexylene and octylene homologues and biphasically by the butylene and pentylene homologues. Biphasic displacement curves were converted to monophasic ones by 10 microM guanosine-5'-O-(3-thiotriphosphate. In conclusion, the homologue of histamine with five methylene groups is a more potent H3 receptor antagonist in the guinea pig jejunum than the other homologues tested. Furthermore, the propylene, butylene and pentylene homologues can discriminate between the two functional H3 receptor models in the guinea pig jejunum and mouse brain. These data are discussed in relation to the efficiency of receptor coupling and receptor heterogeneity.

  4. Star formation in M33 (HerM33es)

    CERN Document Server

    Kramer, C; Braine, J; Buchbender, C; Calzetti, D; Gratier, P; Mookerjea, B; Relano, M; Verley, S

    2011-01-01

    Within the key project "Herschel M33 extended survey" (HerM33es), we are studying the physical and chemical processes driving star formation and galactic evolution in the nearby galaxy M33, combining the study of local conditions affecting individual star formation with properties only becoming apparent on global scales. Here, we present recent results obtained by the HerM33es team. Combining Spitzer and Herschel data ranging from 3.6um to 500um, along with HI, Halpha, and GALEX UV data, we have studied the dust at high spatial resolutions of 150pc, providing estimators of the total infrared (TIR) brightness and of the star formation rate. While the temperature of the warm dust at high brightness is driven by young massive stars, evolved stellar populations appear to drive the temperature of the cold dust. Plane-parallel models of photon dominated regions (PDRs) fail to reproduce fully the [CII], [OI], and CO maps obtained in a first spectroscopic study of one 2'x2' subregion of M33, located on the inner, nor...

  5. Cloning of rat sp56, the homologue of mouse sperm ZP3 receptor-sp56

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Mouse sp56 is considered as one of the candidates for mouse zona pellucida 3 (mZP3) receptor. Up to date, its homologue has only been cloned from guinea pig, namely AM67. Based on the cDNA sequence of mouse sp56, we designed a pair of primer to amplify its homologue from rat testis cDNA. Using RT-PCR,two fragments of 743 bp and 938 bp were amplified. The PCR products show very high homology to mouse sp56. However, the 743 bp product completely lacks one of the seven Sushi domains of mouse sp56. Using the 743 bp product as the probe to detect the expression profile of sp56 in rat tissues, Northern blot shows that a ~2.0 kb mRNA expresses specifically in testis. Employed the RACE method, two full cDNA sequences of rat sp56 were obtained. A Mr ~42 KD band was detected in denatured and non-reducing protein sample of rat testis and sperm with anti-mouse sp56 monoclonal antibody by Western blot method. Rat sp56was localized on rat sperm head by the indirect immunofiuorescence method. Rat sp56 immunoreactivitywas detected from the early pachytene spermatocytes and throughout the spermatogenesis. Its cloning willfurther our understanding of the mechanism of the sperm-egg recognition and binding.

  6. A C. elegans stretch receptor neuron revealed by a mechanosensitive TRP channel homologue.

    Science.gov (United States)

    Li, Wei; Feng, Zhaoyang; Sternberg, Paul W; Xu, X Z Shawn

    2006-03-30

    The nematode Caenorhabditis elegans is commonly used as a genetic model organism for dissecting integration of the sensory and motor systems. Despite extensive genetic and behavioural analyses that have led to the identification of many genes and neural circuits involved in regulating C. elegans locomotion behaviour, it remains unclear whether and how somatosensory feedback modulates motor output during locomotion. In particular, no stretch receptors have been identified in C. elegans, raising the issue of whether stretch-receptor-mediated proprioception is used by C. elegans to regulate its locomotion behaviour. Here we have characterized TRP-4, the C. elegans homologue of the mechanosensitive TRPN channel. We show that trp-4 mutant worms bend their body abnormally, exhibiting a body posture distinct from that of wild-type worms during locomotion, suggesting that TRP-4 is involved in stretch-receptor-mediated proprioception. We show that TRP-4 acts in a single neuron, DVA, to mediate its function in proprioception, and that the activity of DVA can be stimulated by body stretch. DVA both positively and negatively modulates locomotion, providing a unique mechanism whereby a single neuron can fine-tune motor activity. Thus, DVA represents a stretch receptor neuron that regulates sensory-motor integration during C. elegans locomotion.

  7. The nicotinic acetylcholine receptor and its prokaryotic homologues: Structure, conformational transitions & allosteric modulation.

    Science.gov (United States)

    Cecchini, Marco; Changeux, Jean-Pierre

    2015-09-01

    Pentameric ligand-gated ion channels (pLGICs) play a central role in intercellular communications in the nervous system by converting the binding of a chemical messenger - a neurotransmitter - into an ion flux through the postsynaptic membrane. Here, we present an overview of the most recent advances on the signal transduction mechanism boosted by X-ray crystallography of both prokaryotic and eukaryotic homologues of the nicotinic acetylcholine receptor (nAChR) in conjunction with time-resolved analyses based on single-channel electrophysiology and Molecular Dynamics simulations. The available data consistently point to a global mechanism of gating that involves a large reorganization of the receptor mediated by two distinct quaternary transitions: a global twisting and a radial expansion/contraction of the extracellular domain. These transitions profoundly modify the organization of the interface between subunits, which host several sites for orthosteric and allosteric modulatory ligands. The same mechanism may thus mediate both positive and negative allosteric modulations of pLGICs ligand binding at topographically distinct sites. The emerging picture of signal transduction is expected to pave the way to new pharmacological strategies for the development of allosteric modulators of nAChR and pLGICs in general. This article is part of the Special Issue entitled 'The Nicotinic Acetylcholine Receptor: From Molecular Biology to Cognition'. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Chemical Evolution Model of M33

    Science.gov (United States)

    Robles-Valdez, F.; Carigi, L.

    2011-10-01

    We present a chemical evolution model (CEM) of M33 and we find that M33, which is smaller than both M31 and MW, shows a lower gas infall rate, SFR efficiency, and IMF M_{up}. Therefore the CEMs for large spiral galaxies (Carigi et al. 2005; Meneses-Goytia et al. 2011) can be scaled to a smaller galaxy.

  9. Diffuse interstellar bands in M33

    CERN Document Server

    Smith, Keith T; Evans, Christopher J; Cox, Nick L J; Sarre, Peter J

    2013-01-01

    We present the first sample of diffuse interstellar bands (DIBs) in the nearby galaxy M33. Studying DIBs in other galaxies allows the behaviour of the carriers to be examined under interstellar conditions which can be quite different from those of the Milky Way, and to determine which DIB properties can be used as reliable probes of extragalactic interstellar media. Multi-object spectroscopy of 43 stars in M33 has been performed using Keck/DEIMOS. The stellar spectral types were determined and combined with literature photometry to determine the M33 reddenings E(B-V)_M33. Equivalent widths or upper limits have been measured for the {\\lambda}5780 DIB towards each star. DIBs were detected towards 20 stars, demonstrating that their carriers are abundant in M33. The relationship with reddening is found to be at the upper end of the range observed in the Milky Way. The line of sight towards one star has an unusually strong ratio of DIB equivalent width to E(B-V)_M33, and a total of seven DIBs were detected towards...

  10. Structure and Function of CC-Chemokine Receptor 5 Homologues Derived from Representative Primate Species and Subspecies of the Taxonomic Suborders Prosimii and Anthropoidea

    OpenAIRE

    2003-01-01

    A chemokine receptor from the seven-transmembrane-domain G-protein-coupled receptor superfamily is an essential coreceptor for the cellular entry of human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV) strains. To investigate nonhuman primate CC-chemokine receptor 5 (CCR5) homologue structure and function, we amplified CCR5 DNA sequences from peripheral blood cells obtained from 24 representative species and subspecies of the primate suborders Prosimii (family L...

  11. M33: THE EXISTENCE OF A BAR

    Directory of Open Access Journals (Sweden)

    I. Hernández-López

    2009-01-01

    Full Text Available A signi cant fraction of galaxies in the Local Universe classi ed as unbarred in the RC3 turn out to be barred in optical and NIR wavelengths. In the Local Group the Milky Way and M31 have shown to be barred as well, this also could be the case of M33. In this paper we present the results of the Ellipse tting and bidimensional Fourier Analysis, on the R and I bands, deprojected and non-deprojected, images of M33 obtained from DSS2 and Spitzer-IRAC.

  12. Metallicity and mean age across M33

    CERN Document Server

    Cioni, M -R L; Ferguson, A M N; McConnachie, A; Conn, B C; Huxor, A; Ibata, R; Lewis, G; Tanvir, N

    2007-01-01

    New wide-field near-infrared (NIR) imaging observations of M33 were obtained from UKIRT. These show a large population of intermediate-age stars considerably improving on previous NIR data. The spatial distribution of super giant stars, carbon-rich (C-rich or C stars) and oxygen-rich (O-rich or M stars) asymptotic giant branch (AGB) stars distinguished from the NIR colour-magnitude diagram (CMD) have been studied as well as the C/M ratio. The Ks magnitude distribution has been interpreted using theoretical models to derive the mean age and the mean metallicity across M33.

  13. Conformationally restrained carbamoylcholine homologues. Synthesis, pharmacology at neuronal nicotinic acetylcholine receptors and biostructural considerations

    DEFF Research Database (Denmark)

    de la Fuente Revenga, M; Balle, Thomas; Jensen, Anders A.

    2015-01-01

    Exploration of small selective ligands for the nicotinic acetylcholine receptors (nAChRs) based on acetylcholine (ACh) has led to the development of potent agonists with clear preference for the α4β2 nAChR, the most prevalent nAChR subtype in the central nervous system. In this work we present th...

  14. Molecular pharmacology of homologues of ibotenic acid at cloned metabotropic glutamic acid receptors

    DEFF Research Database (Denmark)

    Bräuner-Osborne, Hans; Nielsen, B; Krogsgaard-Larsen, P

    1998-01-01

    We have studied the effects of the enantiomers of 2-amino-3-(3-hydroxyisoxazol-5-yl)propionic acid (homoibotenic acid, HIBO) and analogues substituted with a methyl, bromo or butyl group in the four position of the ring at cloned metabotropic glutamate (mGlu) receptors expressed in Chinese hamste...

  15. Particularly Efficient Star Formation in M33

    CERN Document Server

    Gardan, E; Schuster, K F; Brouillet, N; Sievers, A

    2007-01-01

    The Star Formation (SF) rate in galaxies is an important parameter at all redshifts and evolutionary stages of galaxies. In order to understand the increased SF rates in intermediate redshift galaxies one possibility is to study star formation in local galaxies with properties frequently found at this earlier epoch like low metallicity and small size. We present sensitive observations of the molecular gas in M 33, a small Local Group spiral at a distance of 840 kpc which shares many of the characteristics of the intermediate redshift galaxies. The observations were carried out in the CO(2--1) line with the HERA heterodyne array on the IRAM 30 m telescope. A 11\\arcmin$\\times$22\\arcmin region in the northern part of M 33 was observed, reaching a detection threshold of a few 10$^{3}$ \\msol. The correlation in this field between the CO emission and tracers of SF (8\\mum, 24\\mum, \\Ha, FUV) is excellent and CO is detected very far North, showing that molecular gas forms far out in the disk even in a small spiral wit...

  16. Molecular-Dynamics Simulations of ELIC a Prokaryotic Homologue of the Nicotinic Acetylcholine Receptor

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Xiaolin [ORNL; Ivanov, Ivaylo N [ORNL; Wang, Hailong [Mayo Clinic College of Medicine; McCammon, Jonathan [ORNL

    2009-01-01

    The ligand-gated ion channel from Erwinia chrysanthemi (ELIC) is a prokaryotic homolog of the eukaryotic nicotinic acetylcholine receptor (nAChR) that responds to the binding of neurotransmitter acetylcholine and mediates fast signal transmission. ELIC is similar to the nAChR in its primary sequence and overall subunit organization, but despite their structural similarity, it is not clear whether these two ligand-gated ion channels operate in a similar manner. Further, it is not known to what extent mechanistic insights gleaned from the ELIC structure translate to eukaryotic counterparts such as the nAChR. Here we use molecular-dynamics simulations to probe the conformational dynamics and hydration of the transmembrane pore of ELIC. The results are compared with those from our previous simulation of the human ?7 nAChR. Overall, ELIC displays increased stability compared to the nAChR, whereas the two proteins exhibit remarkable similarity in their global motion and flexibility patterns. The majority of the increased stability of ELIC does not stem from the deficiency of the models used in the simulations, and but rather seems to have a structural basis. Slightly altered dynamical correlation features are also observed among several loops within the membrane region. In sharp contrast to the nAChR, ELIC is completely dehydrated from the pore center to the extracellular end throughout the simulation. Finally, the simulation of an ELIC mutant substantiates the important role of F246 on the stability, hydration and possibly function of the ELIC channel.

  17. Chandra ACIS Survey of M33 (ChASeM33): A First Look

    CERN Document Server

    Plucinsky, Paul P; Long, Knox S; Gaetz, Terrance J; Sasaki, Manami; Pietsch, Wolfgang; Tuellmann, Ralph; Smith, Randall K; Blair, William P; Helfand, David; Hughes, John P; Winkler, P Frank; de Avillez, Miguel; Bianchi, Luciana; Breitschwerdt, Dieter; Edgar, Richard J; Ghavamian, Parviz; Grindlay, Jonathan; Haberl, Frank; Kirshner, Robert; Kuntz, Kip; Mazeh, Tsevi; Pannuti, Thomas G; Shporer, Avi; Thilker, David A

    2007-01-01

    We present an overview of the Chandra ACIS Survey of M33 (ChASeM33): A Deep Survey of the Nearest Face-on Spiral Galaxy. The 1.4 Ms survey covers the galaxy out to $R \\approx 18\\arcmin (\\approx 4$ kpc). These data provide the most intensive, high spatial resolution assessment of the X-ray source populations available for the confused inner regions of M33. Mosaic images of the ChASeM33 observations show several hundred individual X-ray sources as well as soft diffuse emission from the hot interstellar medium. Bright, extended emission surrounds the nucleus and is also seen from the giant \\hii regions NGC 604 and IC 131. Fainter extended emission and numerous individual sources appear to trace the inner spiral structure. The initial source catalog, arising from $\\sim$~2/3 of the expected survey data, includes 394 sources significant at the $3\\sigma$ confidence level or greater, down to a limiting luminosity (absorbed) of $\\sim$1.6\\ergs{35} (0.35 -- 8.0 keV). The hardness ratios of the sources separate those wit...

  18. The molecular gas mass of M33

    CERN Document Server

    Gratier, P; Schuster, K; Rosolowsky, E; Boquien, M; Calzetti, D; Combes, F; Kramer, C; Henkel, C; Herpin, F; Israel., F; Koribalski, B S; Mookerjea, B; Tabatabaei, F S; Röllig, M; van der Tak, F F S; van der Werf, P; Wiedner, M

    2016-01-01

    [Abridged] Do some environments favor efficient conversion of molecular gas into stars? To answer this, we need to be able to estimate the H2 mass. Traditionally, this is done using CO and a few assumptions but the Herschel observations in the FIR make it possible to estimate the molecular gas mass independently of CO. Previous attempts to derive gas masses from dust emission suffered from biases. Generally, dust surface densities, HI column densities, and CO intensities are used to derive a gas-to-dust ratio (GDR) and the local CO intensity to H2 column density ratio (XCO), sometimes allowing for an additional CO-dark gas component (Kdark). We tested earlier methods, revealing degeneracies among the parameters, and then used a Bayesian formalism to derive the most likely values for each of the parameters mentioned above as a function of position in the nearby low metallicity spiral galaxy M33. The data are from the IRAM 30m CO(2-1) line, high-resolution HI and Herschel dust continuum observations. Solving fo...

  19. The molecular gas mass of M 33

    Science.gov (United States)

    Gratier, P.; Braine, J.; Schuster, K.; Rosolowsky, E.; Boquien, M.; Calzetti, D.; Combes, F.; Kramer, C.; Henkel, C.; Herpin, F.; Israel, F.; Koribalski, B. S.; Mookerjea, B.; Tabatabaei, F. S.; Röllig, M.; van der Tak, F. F. S.; van der Werf, P.; Wiedner, M.

    2017-03-01

    Do some environments favor efficient conversion of molecular gas into stars? To answer this, we need to be able to estimate the H2 mass. Traditionally, this is done using CO observations and a few assumptions but the Herschel observations which cover the far-IR dust spectrum make it possible to estimate the molecular gas mass independently of CO and thus to investigate whether and how the CO traces H2. Previous attempts to derive gas masses from dust emission suffered from biases. Generally, dust surface densities, H i column densities, and CO intensities are used to derive a gas-to-dust ratio (GDR) and the local CO intensity to H2 column density ratio (XCO), sometimes allowing for an additional CO-dark gas component (Kdark). We tested earlier methods, revealing degeneracies among the parameters, and then used a sophisticated Bayesian formalism to derive the most likely values for each of the parameters mentioned above as a function of position in the nearby prototypical low metallicity (12 + log (O/H) 8.4) spiral galaxy M 33. The data are from the IRAM Large Program mapping in the CO(2-1) line along with high-resolution H i and Herschel dust continuum observations. Solving for GDR, XCO, and Kdark in macropixels 500 pc in size, each containing many individual measurements of the CO, H i, and dust emission, we find that (i) allowing for CO dark gas (Kdark) significantly improves fits; (ii) Kdark decreases with galactocentric distance; (iii) GDR is slightly higher than initially expected and increases with galactocentric distance; (iv) the total amount of dark gas closely follows the radially decreasing CO emission, as might be expected if the dark gas is H2 where CO is photodissociated. The total amount of H2, including dark gas, yields an average XCO of twice the galactic value of 2 × 1020 cm-2/ K km s-1, with about 55% of this traced directly through CO. The rather constant fraction of dark gas suggests that there is no large population of diffuse H2 clouds

  20. A Genuine Intermediate-Age Globular Cluster in M33

    CERN Document Server

    Chandar, R; Sarajedini, A; Goudfrooij, P; Chandar, Rupali; Puzia, Thomas H.; Sarajedini, Ata

    2006-01-01

    We present deep integrated-light spectroscopy of nine M33 globular clusters taken with the Hectospec instrument at the MMT Observatory. Based on our spectroscopy and previous deep color-magnitude diagrams obtained with HST/WFPC2, we present evidence for the presence of a genuine intermediate-age globular cluster in M33. The analysis of Lick line indices indicates that all globular clusters are metal-poor ([Z/H] <~ -1.0) and that cluster M33-C38 is about 5-8 Gyr younger than the rest of the sample M33 star clusters. We find no evidence for a population of blue horizontal branch stars in the CMD of M33-C38, which rules out the possibility of an artificially young spectroscopic age due to the presence of hot stars. We infer a total mass of 5-9 x 10^4 M_sol for M33-C38, which implies that M33-C38 has survived ~2-3 times longer than some dynamical evolution model predictions for star clusters in M33, although it is not yet clear to which dynamical component of M33 - thin disk, thick disk, halo - the cluster is ...

  1. Muscle cell migrations of C. elegans are mediated by the alpha-integrin INA-1, Eph receptor VAB-1, and a novel peptidase homologue MNP-1.

    Science.gov (United States)

    Tucker, Morgan; Han, Min

    2008-06-15

    Cell migration is a fundamental process occurring during embryonic development and tissue morphogenesis. In the nematode Caenorhabditis elegans, morphogenesis of the body-wall musculature involves short-range migrations of 81 embryonic muscle cells from the lateral surface of the embryo towards the dorsal and ventral midlines. This study shows that mutations in ina-1 (alpha-integrin), as well as vab-1 (Eph receptor), and vab-2 (ephrin), display defects in embryonic muscle cell migration. Furthermore, an RNAi-based enhancer screen in an ina-1 weak loss-of-function background identified mnp-1 (matrix non-peptidase homologue-1) as a previously uncharacterized gene required for promoting proper migration of the embryonic muscle cells. mnp-1 encodes a membrane associated metalloproteinase homologue that is predicted to be catalytically inactive. Our data suggest that MNP-1 is expressed in migrating muscle cells and localizes to the plasma membrane with the non-peptidase domain exposed to the extra-cellular environment. Double-mutant analysis between mnp-1(RNAi), ina-1, and vab-1 mutations; as well as tissue specific rescue experiments; indicated that each of these gene products function predominantly independent of each other and from different cell types to affect muscle cell migration. Together these results suggest complex interactions between the adjacent epidermal, neuronal, and muscle cells are required to promote proper muscle cell migration during embryogenesis.

  2. Prorenin Receptor Homologue VHA-20 is Critical for Intestinal pH Regulation, Ion and Water Management and Larval Development in C. elegans.

    Science.gov (United States)

    Zima, V; Šebková, K; Šimečková, K; Dvořák, T; Saudek, V; Kostrouchová, M

    2015-01-01

    The prorenin receptor (ATP6AP2) is a multifunctional transmembrane protein; it is a constituent of proton-translocating V-ATPase, a non-proteolytic activator of renin and an adaptor in the Wnt/β-catenin pathway. Here, we studied vha-20, one of the two prorenin receptor homologues that are identified by sequence similarity in the C. elegans genome. We show that vha-20 (R03E1.2) is prominently expressed in the intestine, in the excretory cell and in amphid neurons, tissues critical for regulation of ion and water management. The expression of vha-20 in the intestine is dependent on NHR-31, a nuclear receptor related to HNF4. VHA-20 is indispensable for normal larval development, acidification of the intestine, and is required for nutrient uptake. Inhibition of vha-20 by RNAi leads to complex deterioration of water and pH gradients at the level of the whole organism including distention of pseudocoelome cavity. This suggests new roles of prorenin receptor in the regulation of body ion and water management and in acidification of intestinal lumen in nematodes.

  3. PROBING THE M33 HALO USING RR LYRAE STARS

    Energy Technology Data Exchange (ETDEWEB)

    Pritzl, Barton J. [Department of Physics and Astronomy, University of Wisconsin-Oshkosh, Oshkosh, WI 54901 (United States); Olszewski, Edward W. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Saha, Abhijit [National Optical Astronomy Observatory, Tucson, AZ 85726 (United States); Venn, Kim A. [Department of Physics and Astronomy, University of Victoria, Elliott Building, Victoria, BC V8P 5C2 (Canada); Skillman, Evan D., E-mail: pritzlb@uwosh.edu, E-mail: eolszewski@as.arizona.edu, E-mail: asaha@noao.edu, E-mail: kvenn@uvic.ca, E-mail: skillman@astro.umn.edu [Astronomy Department, University of Minnesota, Minneapolis, MN 55455 (United States)

    2011-12-15

    We present the discovery of RR Lyrae (RRL) variable stars in two fields of M33 to the southeast of its center using Gemini North observations. In the outermost field (45' to the southeast of the M33 center; projected distance of 10.8 kpc; deprojected distance of about 19 kpc; about 5 V-band disk scale lengths) we detected two RRLs, consisting of one RRab star and one RRc star. An additional variable was found in this field that is a possible Cepheid. The mean g'-band magnitude for the two RRL stars is 25.60 {+-} 0.04 mag. In the other field (25' to the southeast of the M33 center; projected distance of 5.6 kpc; deprojected distance of about 10 kpc; about 3 V-band disk scale lengths) we found 12 RRL stars, all of which are RRab stars. We also detected two candidate Cepheid variables in this field. The mean magnitude for the RRL stars in this field is 25.64 {+-} 0.14 mag. We found a distance modulus of ((m - M){sub 0}) = 24.69 {+-} 0.17 mag from the RRab stars in the field 25' from M33. The mean periods of the RRab stars in both fields (0.630 {+-} 0.002 days, 45' southeast; 0.628 {+-} 0.055 days, 25' southeast) are much longer than found for previously detected RRL stars in the inner regions of M33. This finding argues for a low metallicity for the RRab stars in the field 25' from M33 ([Fe/H] =-1.84 {+-} 0.30 dex). Given these properties, we conclude that the RRLs we have detected belong to the halo of M33 and thus that there is an old component in the outer regions of M33.

  4. The Stellar Oxygen Abundance Gradient in M33

    Science.gov (United States)

    Monteverde, M. I.; Herrero, A.; Lennon, D. J.; Kudritzki, R.-P.

    1997-01-01

    We report here first results concerning stellar oxygen abundances in M33. Non-LTE model atmosphere and non-LTE line formation calculations were used to determine the oxygen abundance of B-type supergiants. By choosing stars located at different projected radial distances to the center of M33, we are able to determine the oxygen abundance gradient, for which we obtain a value of -0.16 +/- 0.06 dex kpc-1. This is the first time that the oxygen stellar abundance gradient has been determined in a spiral galaxy other than the Milky Way.

  5. The Yellow and Red Supergiants of M33

    CERN Document Server

    Drout, Maria R; Meynet, Georges

    2012-01-01

    Yellow and red supergiants are evolved massive stars whose numbers and locations on the HR diagram can provide a stringent test for models of massive star evolution. Previous studies have found large discrepancies between the relative number of yellow supergiants observed as a function of mass and those predicted by evolutionary models, while a disagreement between the predicted and observed locations of red supergiants on the HR diagram was only recently resolved. Here we extend these studies by examining the yellow and red supergiant populations of M33. Unfortunately, identifying these stars is difficult as this portion of the color-magnitude diagram is heavily contaminated by foreground dwarfs. We identify the red supergiants through a combination of radial velocities and a two-color surface gravity discriminant and, after re-characterizing the rotation curve of M33 with our newly selected red supergiants, we identify the yellow supergiants through a combination of radial velocities and the strength of the...

  6. HI clouds in the proximity of M33

    CERN Document Server

    Grossi, M; Corbelli, E; Giovanelli, R; Haynes, M P; Martin, A M; Saintonge, A; Dowell, J D

    2008-01-01

    Neutral hydrogen clouds are found in the Milky Way and Andromeda halo both as large complexes and smaller isolated clouds. Here we present a search for Hi clouds in the halo of M33, the third spiral galaxy of the Local Group. We have used two complementary data sets: a 3^o x 3^o map of the area provided by the Arecibo Legacy Fast ALFA (ALFALFA) survey and deeper pointed observations carried out with the Arecibo telescope in two fields that permit sampling of the north eastern and south-western edges of the HI disc. The total amount of Hi around M33 detected by our survey is $\\sim 10^7$ M$_{\\odot}$. At least 50% of this mass is made of HI clouds that are related both in space and velocity to the galaxy. We discuss several scenarios for the origin of these clouds focusing on the two most interesting ones: $(a)$ dark-matter dominated gaseous satellites, $(b)$ debris from filaments flowing into M33 from the intergalactic medium or generated by a previous interaction with M31. Both scenarios seem to fit with the o...

  7. Structural Parameters for 10 Halo Globular Clusters in M33

    Science.gov (United States)

    Ma, Jun

    2015-05-01

    In this paper, we present the properties of 10 halo globular clusters (GCs) with luminosities L ≃ 5-7 × 105 L⊙ in the Local Group galaxy M33 using images from the Hubble Space Telescope WFPC2 in the F555W and F814W bands. We obtained the ellipticities, position angles, and surface brightness profiles for each GC. In general, the ellipticities of the M33 sample clusters are similar to those of the M31 clusters. The structural and dynamical parameters are derived by fitting the profiles to three different models combined with mass-to-light ratios (M/L values) from population-synthesis models. The structural parameters include core radii, concentration, half-light radii, and central surface brightness. The dynamical parameters include the integrated cluster mass, integrated binding energy, central surface mass density, and predicted line of sight velocity dispersion at the cluster center. The velocity dispersions of the four clusters predicted here agree well with the observed dispersions by Larsen et al. The results here showed that the majority of the sample halo GCs are better fitted by both the King model and the Wilson model than the Sérsic model. In general, the properties of the clusters in M33, M31, and the Milky Way fall in the same regions of parameter spaces. The tight correlations of cluster properties indicate a “fundamental plane” for clusters, which reflects some universal physical conditions and processes operating at the epoch of cluster formation.

  8. DNA sequence analysis of conserved and unique regions of swinepox virus: identification of genetic elements supporting phenotypic observations including a novel G protein-coupled receptor homologue.

    Science.gov (United States)

    Massung, R F; Jayarama, V; Moyer, R W

    1993-12-01

    Swinepox virus (SPV) contains a double-stranded cross-linked linear DNA genome of approximately 175 kilobase pairs with terminal inverted repetitions (TIRs) of 4.3 kb. The nucleotide sequence was determined for fragments from several regions of the genome including a 2.85-kb fragment from the central potentially conserved portion and two fragments within the presumed variable near-terminal regions which tend to be unique to a given poxvirus. The core sequence contains one partial and two complete open reading frames that are highly conserved and colinear with three contiguous ORFs within the HindIII D fragment of vaccinia virus (VV). The two near-terminal fragments, encompassing 14.2 and 3.6 kb, are respectively located 2.1 kb internal to the left and right cross-linked termini of the DNA and span the TIR junctions. The sequences encode 25 open reading frames including numerous proteins predicted to be membrane-bound or secreted in infected cells. Several ORFs unique to SPV were identified that may be involved in cell attachment, immune modulation, and pathogenesis including a novel poxvirus G protein-coupled receptor. In addition, several polypeptides encoded within the near-terminal regions of vaccinia virus DNA that function as host range or virulence factors are lacking within this region of swinepox virus including the VV growth factor, complement-binding protein, and ORFs C7L and K1L, associated with host range. The lack of these functional homologues could explain the characteristic attenuated phenotype and limited host range of SPV.

  9. The Herschel M33 extended survey (HerM33es): PACS spectroscopy of the star forming region BCLMP 302

    CERN Document Server

    Mookerjea, B; Buchbender, C; Boquien, M; Verley, S; Relano, M; Quintana-Lacaci, G; Aalto, S; Braine, J; Calzetti, D; Combes, F; Garcia-Burillo, S; Gratier, P; Henkel, C; Israel, F; Lord, S; Nikola, T; Roellig, M; Stacey, G; Tabatabaei, F S; van der Tak, F; van der Werf, P

    2011-01-01

    Context: The emission line of [CII] at 158 micron is one of the strongest cooling lines of the interstellar medium (ISM) in galaxies. Aims: Disentangling the relative contributions of the different ISM phases to [CII] emission, is a major topic of the HerM33es program, a Herschel key project to study the ISM in the nearby spiral galaxy M33. Methods: Using PACS, we have mapped the emission of [CII] 158 micron, [OI] 63 micron, and other FIR lines in a 2'x2' region of the northern spiral arm of M33, centered on the HII region BCLMP302. At the peak of H-alpha emission, we have observed in addition a velocity resolved [CII] spectrum using HIFI. We use scatterplots to compare these data with PACS 160 micron continuum maps, and with maps of CO and HI data, at a common resolution of 12 arcsec or 50 pc. Maps of H-alpha and 24 micron emission observed with Spitzer are used to estimate the SFR. We have created maps of the [CII] and [OI] 63 micron emission and detected [NII] 122 micron and NIII 57 micron at individual po...

  10. M33 @ Observatorio Astrofísico de Javalambre

    Science.gov (United States)

    Vázquez Ramió, H.; Ederoclite, A.; Lamadrid, J. L.; Blanco Siffert, B.; San Roman, I.; Cristóbal-Hornillos, D.; Varela, J.; Coelho, P.; Moles, M.; Cenarro, A. J.; Marín-Franch, A.; Díaz-Martín, C. M.; Iglesias Marzoa, R.; Tilve, V.; Rodríguez, S.; Maícas, N.; López San Juan, C.; Viironen, K.; Vilella Rojo, G.; Logroño García, R.; Abril Ibánez, J.

    2017-03-01

    M33, the Triangulum Galaxy, is a spiral galaxy in the Local Group. Given its brightness and its vicinity with Andromeda Galaxy (M31), it is one of the best studied objects of the Northern hemisphere. In this poster, we present observations carried out with the JAST/T80 at the Observatorio Astrofísico de Javalambre. The extraordinary field of view of this telescope allows us to study the stellar populations of the galaxy with a single observation. Moreover, repeated observations have provided us the possibility to follow a variety of variable stars, among them the nova ASASSN-15th.

  11. M33 A Galaxy with No Supermassive Black Hole

    CERN Document Server

    Gebhardt, K; Kormendy, J; Pinkney, J C; Bower, G A; Green, R; Gull, T R; Hutchings, J B; Joseph, C L; Kaiser, M E; Nelson, C H; Richstone, D O; Weistrop, D; Gebhardt, Karl; Lauer, Tod R.; Kormendy, John; Pinkney, Jason; Bower, Gary A.; Green, Richard; Gull, Theodore; Joseph, Chuck; Nelson, Charles H.; Richstone, Douglas; Weistrop, Donna

    2001-01-01

    Galaxies that contain bulges appear to contain central black holes whose masses correlate with the velocity dispersion of the bulge. We show that no corresponding relationship applies in the pure disk galaxy M33. Three-integral dynamical models fit Hubble Space Telescope WFPC2 photometry and STIS spectroscopy best if the central black hole mass is zero. The upper limit is 1500 M_sun. This is significantly below the mass expected from the velocity dispersion of the nucleus and far below any mass predicted from the disk kinematics. Our results suggest that supermassive black holes are associated only with galaxy bulges and not with their disks or dark halos.

  12. Estimating the Metallicity of Old Star Clusters in M33

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Based on the method proposed by Kong et al. And on the multi-color spectrophotometry by Ma et al., we estimate the metallicities of 16 old star clusters in the nearby spiral galaxy M33, ten of which are halo globular clusters. These old clusters are all metal poor, the range of metallicity ([Fe/H]) is from -0.14 to -2.12.In general, our results are consistent with those derived by other methods, such as integrated spectra and photometry, and our study confirms the reliability of the method of Kong et al.

  13. Pepsin homologues in bacteria

    Directory of Open Access Journals (Sweden)

    Bateman Alex

    2009-09-01

    Full Text Available Abstract Background Peptidase family A1, to which pepsin belongs, had been assumed to be restricted to eukaryotes. The tertiary structure of pepsin shows two lobes with similar folds and it has been suggested that the gene has arisen from an ancient duplication and fusion event. The only sequence similarity between the lobes is restricted to the motif around the active site aspartate and a hydrophobic-hydrophobic-Gly motif. Together, these contribute to an essential structural feature known as a psi-loop. There is one such psi-loop in each lobe, and so each lobe presents an active Asp. The human immunodeficiency virus peptidase, retropepsin, from peptidase family A2 also has a similar fold but consists of one lobe only and has to dimerize to be active. All known members of family A1 show the bilobed structure, but it is unclear if the ancestor of family A1 was similar to an A2 peptidase, or if the ancestral retropepsin was derived from a half-pepsin gene. The presence of a pepsin homologue in a prokaryote might give insights into the evolution of the pepsin family. Results Homologues of the aspartic peptidase pepsin have been found in the completed genomic sequences from seven species of bacteria. The bacterial homologues, unlike those from eukaryotes, do not possess signal peptides, and would therefore be intracellular acting at neutral pH. The bacterial homologues have Thr218 replaced by Asp, a change which in renin has been shown to confer activity at neutral pH. No pepsin homologues could be detected in any archaean genome. Conclusion The peptidase family A1 is found in some species of bacteria as well as eukaryotes. The bacterial homologues fall into two groups, one from oceanic bacteria and one from plant symbionts. The bacterial homologues are all predicted to be intracellular proteins, unlike the eukaryotic enzymes. The bacterial homologues are bilobed like pepsin, implying that if no horizontal gene transfer has occurred the duplication

  14. Giant Molecular Clouds in the Local Group Galaxy M33

    CERN Document Server

    Gratier, P; Rodriguez-Fernandez, N J; Schuster, K F; Kramer, C; Corbelli, E; Combes, F; Brouillet, N; van der Werf, P P; Röllig, M

    2011-01-01

    We present an analysis of the systematic CO(2-1) survey at 12" resolution covering most of the local group spiral M 33 which, at a distance of 840 kpc, is close enough that individual giant molecular clouds (GMCs) can be identified. The goal of this work is to study the properties of the GMCs in this subsolar metallicity galaxy. The CPROPS (Cloud Properties) algorithm (Rosolowsky & Leroy 2006) was used to identify 337 GMCs in M 33, the largest sample to date in an external galaxy. The sample is used to study the GMC luminosity function, or mass spectrum under the assumption of a constant N(H2)/ICO ratio. We find that n(L)dL = K*L^(-2.0\\pm0.1) for the entire sample. However, when the sample is divided into inner and outer disk samples, the exponent changes from 1.6 \\pm 0.2 for the centre 2 kpc to 2.3 \\pm 0.2 for galactocentric distances larger than 2 kpc. Based on the emission in the FUV, Halpha, 8mu, and 24mu bands, each cloud was classified in terms of its star forming activity - no star formation, embed...

  15. Stellar structures in the outer regions of M33

    CERN Document Server

    Grossi, M; Corbelli, E; Giovanardi, C; Okamoto, S; Arimoto, N

    2011-01-01

    We present Subaru/Suprime-Cam deep V and I imaging of seven fields in the outer regions of M33. Our aim is to search for stellar structures in correspondence of extended HI clouds found in a recent 21-cm survey of the galaxy. Three fields probe the southeastern (SE) side of the galaxy in correspondence of a large HI complex. Other three fields cover the northwestern (NW) side of the galaxy along the HI warp. A final target field was chosen further north, at a projected distance of approximately 25 kpc, to study part of the large stellar plume recently discovered around M33. We analyse the stellar population at R > 10 kpc by means of V, I colour magnitude diagrams reaching the Red Clump. Evolved stellar populations are found in all fields out to 120' (~ 30 kpc), while a diffuse population of young stars (~ 200 Myr) is detected out to a galactocentric radius of 15 kpc. The mean metallicity in the southern fields remains approximately constant at [M/H] = -0.7 beyond the edge of the optical disc, from 40' out to ...

  16. Angular Momentum Constraints on GMC formation in M33

    Science.gov (United States)

    Rosolowsky, E.; Engargiola, G.; Plambeck, R.; Blitz, L.

    2001-12-01

    We present the results of the complete CO 12CO(1-> 0) survey of the molecular gas in M33. These observations represent the first survey of all of the GMCs in a spiral galaxy; CO surveys of the Milky Way are too severely blended in some regions to separate the GMCs from one another. These observations show that individual molecular clouds share many properties with those found in the Milky Way although the most massive GMC in M33 has a mass of only 7x 105 Msun and is not associated with an Hii region. Moreover, the specific angular momentum of the GMCs is more than an order of magnitude smaller than expected for basic formation scenarios. The observational campaign consists of two parts: 1) a complete survey of the star forming disk which represents a complete census of GMCs down to the Taurus cloud mass at low spatial resolution and high surface brightness sensitivity and 2) high resolution follow-up observations which spatially resolve the molecular clouds providing information on rotation properties, virial masses, and morphology. From the latter, we estimate the angular momentum imparted through galactic shear by Jeans collapse, the Toomre instability and the Parker instability, all of which impart much more angular momentum to the clouds than is observed. We propose the magnetic fields that thread the molecular clouds and connect to the diffuse interstellar medium brake the spin-up of the progenitor gas, suggesting that the formation of GMCs is a magnetohydrodynamic process.

  17. Properties of Optically Selected Supernova Remnant Candidates in M33

    CERN Document Server

    Lee, Jong Hwan

    2014-01-01

    We present a sample of supernova remnant (SNR) candidates in M33 based on optical narrow band images in the Local Group Survey. We identify emission line objects that have enhanced [SII]:H{\\alpha} (> 0.4) and circular shapes using continuum-subtracted H{\\alpha}and [SII] images and produce a list of 199 SNR candidates, of which 79 are previously unknown. We classify them considering two types of criteria: their progenitor type (Type Ia and core-collapse (CC) SNRs) and their morphological type. Of the total sample, 170 are likely remnants of CC SNe and 29 are likely remnants of Type Ia SNe. We obtain a cumulative size distribution of the SNR candidates, showing that it follows a power law with an index,{\\alpha}= 2.38{\\pm}0.05 (17 < D < 50 pc). This indicates that most of the M33 SNR candidates found in this study are in the Sedov-Taylor phase, consistent with previous findings. The [SII]:H{\\alpha} distribution of the SNR candidates shows two peaks at [SII]:H{\\alpha} ~0.55 and ~0.8. Interestingly X-ray and...

  18. Variation in the dust emissivity index across M 33 with Herschel and Spitzer (HerM 33es)

    Science.gov (United States)

    Tabatabaei, F. S.; Braine, J.; Xilouris, E. M.; Kramer, C.; Boquien, M.; Combes, F.; Henkel, C.; Relano, M.; Verley, S.; Gratier, P.; Israel, F.; Wiedner, M. C.; Röllig, M.; Schuster, K. F.; van der Werf, P.

    2014-01-01

    We study the wavelength dependence of the dust emission as a function of position and environment across the disk of M 33 using Spitzer and Herschel photometric data. M 33 is a Local Group spiral with slightly subsolar metallicity, which makes it an ideal stepping-stone to less regular and lower-metallicity objects such as dwarf galaxies and, probably, young-universe objects. Expressing the emissivity of the dust as a power law, the power-law exponent (β) was estimated from two independent approaches designed to properly treat the degeneracy between β and the dust temperature (T). Both β and T are higher in the inner than in the outer disk, contrary to reported β - T anti-correlations found in other sources. In the cold + warm dust model, the warm component and the ionized gas (Hα) have a very similar distribution across the galaxy, demonstrating that the model separates the components in an appropriate way. Both cold- and warm-dust column densities are high in star-forming regions and reach their maxima toward the giant star-forming complexes NGC 604 and NGC 595. β declines from close to 2 in the center to about 1.3 in the outer disk. β is positively correlated with star formation and with the molecular gas column, as traced by the Hα and CO emission. The lower dust-emissivity index in the outer parts of M 33 is most likely related to the reduced metallicity (different grain composition) and possibly to a different size distribution. It is not due to the decrease in stellar radiation field or temperature in a simple way because the far-infrared-bright regions in the outer disk also have a low β. Like most spirals, M 33 has a (decreasing) radial gradient in star formation and molecular-to-atomic gas ratio such that the regions bright in Hα or CO tend to trace the inner disk, which makes it difficult to distinguish between their effects on the dust. The assumption of a constant emissivity index β is obviously not appropriate.

  19. Three supernova shells around a young M33 star cluster

    Science.gov (United States)

    Camps-Fariña, A.; Beckman, J. E.; Font, J.; Borlaff, A.; Zaragoza-Cardiel, J.; Amram, P.

    2016-09-01

    Using a specialized technique sensitive to the presence of expanding ionized gas, we have detected a set of three concentric expanding shells in an H II region in the nearby spiral galaxy M33. After mapping the kinematics in Hα with Fabry-Perot spectroscopy, we used slit spectra to measure the intensities of the [S II] doublet at λλ671.9, 673.1 nm and the [N II] doublet at λλ645.8, 658.3 nm to corroborate the kinematics and apply diagnostic tests using line ratios. These showed that the expanding shells are shock dominated as would be the case if they had originated with supernova explosions. Estimating their kinetic energies, we find fairly low values, indicating a fairly advanced stage of evolution. We obtain density, mass and parent star mass estimates, which, along with the kinetic energies, are inconsistent with the simplest models of shock-interstellar medium interaction. We propose that the presence and properties of an inhomogeneous medium offer a scenario which can account for these observations, and discuss the implications. Comparing our results with data from the literature supports the combined presence of an H II region and supernova remnant material at the observed position.

  20. High Resolution Molecular Gas Maps of M33

    CERN Document Server

    Rosolowsky, E; Matsushita, S; Willner, S

    2007-01-01

    New observations of CO (J=1->0) line emission from M33, using the 25 element BEARS focal plane array at the Nobeyama Radio Observatory 45-m telescope, in conjunction with existing maps from the BIMA interferometer and the FCRAO 14-m telescope, give the highest resolution (13'') and most sensitive (RMS ~ 60 mK) maps to date of the distribution of molecular gas in the central 5.5 kpc of the galaxy. A new catalog of giant molecular clouds (GMCs) has a completeness limit of 1.3 X 10^5 M_sun. The fraction of molecular gas found in GMCs is a strong function of radius in the galaxy, declining from 60% in the center to 20% at galactocentric radius R_gal ~ 4 kpc. Beyond that radius, GMCs are nearly absent, although molecular gas exists. Most (90%) of the emission from low mass clouds is found within 100 pc projected separation of a GMC. In an annulus 2.1< R_gal <4.1 kpc, GMC masses follow a power law distribution with index -2.1. Inside that radius, the mass distribution is truncated, and clouds more massive tha...

  1. Dust Properties in HII Regions in M33

    CERN Document Server

    Relano, M; Lisenfeld, U; Verley, S; Hermelo, I; Boquien, M; Albrecht, M; Kramer, C; Braine, J; Perez-Montero, E; De Looze, I; Xilouris, M; Kovacs, A; Staguhn, J

    2016-01-01

    The conversion of the IR emission into star formation rate can be strongly dependent on the physical properties of the dust, which are affected by the environmental conditions where the dust is embedded. We study here the dust properties of a set of HII regions in the Local Group Galaxy M33 presenting different spatial configurations between the stars, gas and dust to understand the dust evolution under different environments. We model the SED of each region using the DustEM tool and obtain the mass relative to hydrogen for Very Small Grains (YVSG), Polycyclic Aromatic Hydrocarbons (YPAH) and Big Grains (YBG). The relative mass of the VSGs (YVSG/YTOT) is a factor of 1.7 higher for HII regions classified as filled and mixed than for regions presenting a shell structure. The enhancement of VSGs within NGC 604 and NGC 595 is correlated to expansive gas structures with velocities greater than 50 km/s. The gas-to-dust ratio derived for the HII regions in our sample exhibits two regimes related to the HI-H2 transit...

  2. Integral field spectroscopy of HII regions in M33

    CERN Document Server

    López-Hernández, Jesús; Terlevich, Roberto; Rosa-González, Daniel; Díaz, Ángeles; Benito, Rubén García; Vílchez, José; Hägele, Guillermo

    2013-01-01

    Integral field spectroscopy (IFS) is presented for star forming regions in M33. A central area of 300 x 500 pc^2 and the external HII region IC 132, at a galactocentric distance {\\sim} 19arcmin (4.69 kpc) were observed with the Potsdam Multi Aperture Spectrophotometer (PMAS) instrument at the 3.5 m telescope of the Calar Alto Hispano- Alem\\'an observatory (CAHA). The spectral coverage goes from 3600 A to 1{\\mu}m to include from [OII]{\\lambda}3727 A to the near infrared lines required for deriving sulphur electron temperature and abundance diagnostics. Local conditions within individual HII regions are presented in the form of emission line fluxes and physical conditions for each spatial resolution element (spaxel) and for segments with similar H{\\alpha} surface brightness. A clear dichotomy is observed when comparing the central to outer disc HII regions. While the external HII region has higher electron temperature plus larger H{\\beta} equivalent width, size and excitation, the central region has higher exti...

  3. Photometric Properties of the M33 Star Cluster System

    CERN Document Server

    Roman, Izaskun San; Aparicio, Antonio

    2010-01-01

    We present a catalog of 2,990 extended sources in a 1deg x1deg area centered on M33 using the MegaCam camera on the 3.6m Canada-France-Hawaii telescope (CFHT). The catalog includes 599 new candidate stellar clusters, 204 previously confirmed clusters, 1,969 likely background galaxies and 218 unknown extended objects. We present ugriz integrated magnitudes of the candidates and confirmed star clusters as well as full width at half maximum, ellipticity and stellarity. Based on the properties of the confirmed star clusters, we select a sub-sample of highly probable clusters composed of 246 objects. The integrated photometry of the complete cluster catalog reveals a wide range of colors from -0.4 < (g-r) < 1.5 and -1.0 < (r-i) < 1.0 with no obvious cluster subpopulations. Comparisons with models of simple stellar populations suggest a large range of ages some as old as ~ 10 Gyrs. In addition, we find a sequence in the color-color diagrams that deviates from the expected direction of evolution. This fe...

  4. Velocity resolved [CII] spectroscopy of the center and the BCLMP302 region of M33 (HerM33es)

    CERN Document Server

    Mookerjea, B; Kramer, C; Nikola, T; Braine, J; Ossenkopf, V; Roellig, M; Henkel, C; van der Werf, P; van der Tak, F; Wiedner, M C

    2015-01-01

    We aim to understand the contribution of the ionized, atomic and molecular phases of the ISM to the [CII] emission from clouds near the dynamical center and the BCLMP302 HII region in the north of the nearby galaxy M33 at a spatial resolution of 50pc. We combine high resolution [CII] spectra taken with the HIFI spectrometer onboard the Herschel satellite with [CII] Herschel-PACS maps and ground-based observations of CO(2-1) and HI. All data are at a common spatial resolution of 50pc. Typically, the [CII] lines have widths intermediate between the narrower CO(2-1) and broader HI line profiles. We decomposed the [CII] spectra in terms of contribution from molecular and atomic gas detected in CO(2-1) and HI, respectively. We find that the relative contribution of molecular and atomic gas traced by CO(2-1) and HI varies depends mostly on the local physical conditions and geometry. We estimate that 11-60% and 5-34% of the [CII] intensities in the center and in BCLMP302, respectively, arise at velocities showing no...

  5. Variation in the dust emissivity index across M33 with Herschel and Spitzer (HerM33es)

    CERN Document Server

    Tabatabaei, F S; Xilouris, E M; Kramer, C; Boquien, M; Combes, F; Henkel, C; Relano, M; Verley, S; Gratier, P; Israel, F; Wiedner, M C; Roellig, M; Schuster, K F; van derWerf, P

    2013-01-01

    We study the wavelength dependence of the dust emission as a function of position and environment across the disk of M33 at a linear resolution of 160 pc using Spitzer and Herschel photometric data. Expressing the emissivity of the dust as a power law, the power-law exponent (beta) is estimated from two independent approaches designed to properly treat the degeneracy between beta and the dust temperature. Both beta and the dust temperature are higher in the inner disk than in the outer disk, contrary to reported beta-T anti-correlations found in other sources. In the cold + warm dust model, the warm component and the ionized gas (Halpha) have a very similar distribution across the galaxy, demonstrating that the model separates the components in an appropriate fashion. The flocculent spiral arms and the dust lanes are evident in the map of the cold component. Both cold and warm dust column densities are high in star forming regions and reach their maxima toward the giant star forming complexes NGC604 and NGC59...

  6. The wild boar (Sus scrofa Lymphocyte function-associated antigen-1 (CD11a/CD18 receptor: cDNA sequencing, structure analysis and comparison with homologues

    Directory of Open Access Journals (Sweden)

    Bergh Philippe

    2007-10-01

    Full Text Available Abstract Background The most predominant beta2-integrin lymphocyte function-associated antigen-1 (LFA-1, CD11a/CD18, alphaLbeta2, expressed on all leukocytes, is essential for many adhesive functions of the immune system. Interestingly, RTX toxin-producing bacteria specifically target this leukocyte beta2-integrin which exacerbates lesions and disease development. Results This study reports the sequencing of the wild boar beta2-integrin CD11a and CD18 cDNAs. Predicted CD11a and CD18 subunits share all the main structural characteristics of their mammalian homologues, with a larger interspecies conservation for the CD18 than the CD11a. Besides these strong overall similarities, wild boar and domestic pig LFA-1 differ by 2 (CD18 and 1 or 3 (CD11a substitutions, of which one is located in the crucial I-domain (CD11a, E168D. Conclusion As most wild boars are seropositive to the RTX toxin-producing bacterium Actinobacillus pleuropneumoniae and because they have sustained continuous natural selection, future studies addressing the functional impact of these polymorphisms could bring interesting new information on the physiopathology of Actinobacillus pleuropneumoniae-associated pneumonia in domestic pigs.

  7. The autoregulator receptor homologue AvaR3 plays a regulatory role in antibiotic production, mycelial aggregation and colony development of Streptomyces avermitilis.

    Science.gov (United States)

    Miyamoto, Kiyoko T; Kitani, Shigeru; Komatsu, Mamoru; Ikeda, Haruo; Nihira, Takuya

    2011-08-01

    The γ-butyrolactone autoregulator receptor has been shown to control secondary metabolism and/or morphological differentiation across many Streptomyces species. Streptomyces avermitilis produces an important anthelmintic agent (avermectin) and two further polyketide antibiotics, filipin and oligomycin. Genomic analysis of S. avermitilis revealed that this micro-organism has the clustered putative autoregulator receptor genes distant from the antibiotic biosynthetic gene clusters. Here, we describe the characterization of avaR3, one of the clustered receptor genes, which encodes a protein containing an extra stretch of amino acid residues that has not been found in the family of autoregulator receptors. Disruption of avaR3 resulted in markedly decreased production of avermectins, with delayed expression of avermectin biosynthetic genes, suggesting that AvaR3 positively controls the avermectin biosynthetic genes. Moreover, the disruption caused increased production of filipin without any changes in the transcriptional profile of the filipin biosynthetic genes, suggesting that filipin production is indirectly controlled by AvaR3. The avaR3 disruptant displayed fragmented growth in liquid culture and conditional morphological defects on solid medium. These findings demonstrated that AvaR3 acts as a global regulator that controls antibiotic production and cell morphology.

  8. Epidermal growth factor receptor and v-Ki-ras2 Kirsten rat sarcoma viral oncogen homologue-specific amino acid substitutions are associated with different histopathological prognostic factors in resected non-small-cell lung cancer.

    Science.gov (United States)

    Seitlinger, Joseph; Renaud, Stéphane; Falcoz, Pierre-Emmanuel; Schaeffer, Mickaël; Olland, Anne; Reeb, Jérémie; Santelmo, Nicola; Legrain, Michèle; Voegeli, Anne-Claire; Weingertner, Noëlle; Chenard, Marie-Pierre; Beau-Faller, Michèle; Massard, Gilbert

    2016-12-01

    Epidermal growth factor receptor (mEGFR) and v-Ki-ras2 Kirsten rat sarcoma viral oncogen homologue (mKRAS) mutations are the two main oncogenic drivers in resected non-small-cell lung cancer (NSCLC). We aimed to evaluate the correlation between histopathological prognostic factors and these mutations in resected NSCLC. We retrospectively reviewed data from 841 patients who underwent a surgical resection with a curative intent for NSCLC between 2007 and 2012. KRAS mutations were observed in 255 patients (32%) and mEGFR in 103 patients (12%). A correlation was observed between mKRAS patients and lymph node involvement [Cramer's V: 0.451, P V: 0.235, P = 0.02, OR: 3.04 (95% CI: 1.5-6.3), P = 0.004]. High lymph node ratio and angioinvasion were also significantly more frequent in mKRAS [Cramer's V: 0.373, P V: 0.269, P V: 0.459, P V: 0.45, P < 0.001 OR: 21.14 (95% CI: 9.2-48.3), P < 0.001, respectively]. We observed a correlation between mKRAS and negative histopathological prognostic factors and between mEGFR and positive prognostic factors. One can wonder whether histopathological prognostic factors are only clinical reflections of molecular alterations. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  9. Fisetin up-regulates the expression of adiponectin in 3T3-L1 adipocytes via the activation of silent mating type information regulation 2 homologue 1 (SIRT1)-deacetylase and peroxisome proliferator-activated receptors (PPARs).

    Science.gov (United States)

    Jin, Taewon; Kim, Oh Yoen; Shin, Min-Jeong; Choi, Eun Young; Lee, Sung Sook; Han, Ye Sun; Chung, Ji Hyung

    2014-10-29

    Adiponectin, an adipokine, has been described as showing physiological benefits against obesity-related malfunctions and vascular dysfunction. Several natural compounds that promote the expression and secretion of adipokines in adipocytes could be useful for treating metabolic disorders. This study investigated the effect of fisetin, a dietary flavonoid, on the regulation of adiponectin in adipocytes using 3T3-L1 preadipocytes. The expression and secretion of adiponectin increased in 3T3-L1 cells upon treatment with fisetin in a dose-dependent manner. Fisetin-induced adiponectin secretion was inhibited by peroxisome proliferator-activated receptor (PPAR) antagonists. It was also revealed that fisetin increased the activities of PPARs and silent mating type information regulation 2 homologue 1 (SIRT1) in a dose-dependent manner. Furthermore, the up-regulation of adiponectin and the activation of PPARs induced by fisetin were prevented by a SIRT1 inhibitor. Fisetin also promoted deacetylation of PPAR γ coactivator 1 (PGC-1) and its interaction with PPARs. SIRT knockdown by siRNA significantly decreased both adiponectin production and PPARs-PGC-1 interaction. These results provide evidence that fisetin promotes the gene expression of adiponectin through the activation of SIRT1 and PPARs in adipocytes.

  10. Tracing the evolutionary lineage of pattern recognition receptor homologues in vertebrates: An insight into reptilian immunity via de novo sequencing of the wall lizard splenic transcriptome.

    Science.gov (United States)

    Priyam, Manisha; Tripathy, Mamta; Rai, Umesh; Ghorai, Soma Mondal

    2016-04-01

    Reptiles remain a deprived class in the area of genomic and molecular resources for the vertebrate classes. The transition of squamates from aquatic to terrestrial mode of life caused profound changes in their immune system to combat the altered variety of pathogens on land. The current study aims at delineating the evolution of defence mechanisms in wall lizard, Hemidactylus flaviviridis, by exploring its immunome. De novo sequencing of splenic transcriptome from wall lizard on the Illumina Hi-Seq platform generated 258,128 unique transcripts with an average GC content of 45%. Annotation of 555,557 and 6812 transcripts was carried out against NCBI (non-redundant database) and UniProt databases, respectively. The KEGG pathway annotation of transcripts classified them into 39 processes of six pathway function categories. A total of 3824 transcripts, involved in 23 immune-related pathways, were identified in the immune-relevant cluster built by harvesting the genes under KEGG pathways of immune system and immune diseases. Forty-two percent of the immune-relevant cluster was represented by pattern-recognition receptors (PRRs), of which the maximum number of transcripts was attributed to the Toll-like receptor (TLR) signalling pathway. Nine PRRs with potential full-length coding sequences were sorted for phylogenetic analysis and comparative domain analysis across the vertebrate lineage. They included DEC205/lymphocyte antigen 75 (ly75), nucleotide-binding oligomerisation domain-containing protein 1 (NOD1), NOD-like receptor family CARD domain-containing 3 (NLRC3), nucleotide-binding oligomerisation domain, leucine-rich repeat-containing X1 (NLRX1), DDX58/retinoic acid-inducible gene 1 (RIG-1), Toll-like receptor 3 (TLR3), TLR4, TLR5 and TLR7. From selection studies of these genes, we inferred positive selection for ly75, NOD1, RIG-1, TLR3 and TLR4. Apart from contributing to the scarce genomic resources available for reptiles and giving a broad scope for the immune

  11. CHARACTERIZATION OF THE MOST LUMINOUS STAR IN M33: A SUPER SYMBIOTIC BINARY

    Energy Technology Data Exchange (ETDEWEB)

    Mikołajewska, Joanna; Iłkiewicz, Krystian [N. Copernicus Astronomical Center, Bartycka 18, PL 00-716 Warsaw (Poland); Caldwell, Nelson [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Shara, Michael M., E-mail: mikolaj@camk.edu.pl [Department of Astrophysics, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024 (United States)

    2015-01-30

    We present the first spectrum of the most luminous infrared star in M33, and use it to demonstrate that the object is almost certainly a binary composed of a massive O star and a dust-enshrouded red hypergiant. This is the most luminous symbiotic binary ever discovered. Its radial velocity is an excellent match to that of the hydrogen gas in the disk of M33, supporting our interpretation that it is a very young and massive binary star.

  12. Combination of hypomorphic mutations of the Drosophila homologues of aryl hydrocarbon receptor and nucleosome assembly protein family genes disrupts morphogenesis, memory and detoxification.

    Directory of Open Access Journals (Sweden)

    Boris A Kuzin

    Full Text Available Aryl hydrocarbon receptor is essential for biological responses to endogenous and exogenous toxins in mammals. Its Drosophila homolog spineless plays an important role in fly morphogenesis. We have previously shown that during morphogenesis spineless genetically interacts with CG5017 gene, which encodes a nucleosome assembly factor and may affect cognitive function of the fly. We now demonstrate synergistic interactions of spineless and CG5017 in pathways controlling oxidative stress response and long-term memory formation in Drosophila melanogaster. Oxidative stress was induced by low doses of X-ray irradiation of flies carrying hypomorphic mutation of spineless, mutation of CG5017, and their combination. To determine the sensitivity of these mutants to pharmacological modifiers of the irradiation effect, we irradiated flies growing on standard medium supplemented by radiosensitizer furazidin and radioprotector serotonin. The effects of irradiation were investigated by analyzing leg and antenna morphological structures and by using real-time PCR to measure mRNA expression levels for spineless, Cyp6g1 and Gst-theta genes. We also examined long-term memory in these mutants using conditioned courtship suppression paradigm. Our results show that the interaction of spineless and CG5017 is important for regulation of morphogenesis, long-term memory formation, and detoxification during oxidative stress. Since spineless and CG5017 are evolutionary conserved, these results must be considered when evaluating the risk of combining similar mutations in other organisms, including humans.

  13. Involvement of two A-factor receptor homologues in Streptomyces coelicolor A3(2) in the regulation of secondary metabolism and morphogenesis.

    Science.gov (United States)

    Onaka, H; Nakagawa, T; Horinouchi, S

    1998-05-01

    Nucleotide sequences homologous to arpA encoding the A-factor receptor protein (ArpA) of Streptomyces griseus are distributed in a wide variety of streptomycetes. Two genes, cprA and cprB, each encoding an ArpA-like protein were found and cloned from Streptomyces coelicolor A3(2). CprA and CprB shared 90.7% identity in amino acid sequence and both showed about 35% identity to ArpA. Disruption of cprA by use of an M13 phage-derived single-stranded vector resulted in severe reduction of actinorhodin and undecylprodigiosin production. In addition, the timing of sporulation in the cprA disruptants was delayed by 1 day. The cprA gene thus appeared to act as a positive regulator or an accelerator for secondary metabolite formation and sporulation. Consistent with this idea, introduction of cprA on a low-copy-number plasmid into the parental strain led to overproduction of these secondary metabolites and accelerated the timing of sporulation. On the other hand, cprB disruption resulted in precocious and overproduction of actinorhodin. However, almost no effect on undecylprodigiosin was detected in the cprB disruptants. Sporulation of the cprB disruptant began 1 day earlier than the parental strain. The cprB gene thus behaved as a negative regulator on actinorhodin production and sporulation. Consistent with this, extra copies of cprB in the parental strain caused reduced production of actinorhodin and delay in sporulation. It is thus concluded that both cprA and cprB play regulatory roles in both secondary metabolism and morphogenesis in S. coelicolor A3(2), just as the arpA/A-factor system in Streptomyces griseus.

  14. RR Lyrae variable stars in M31-M33 super-halo

    Science.gov (United States)

    Tanakul, Nahathai; Sarajedini, Ata

    2017-01-01

    RR Lyrae variable stars can serve as powerful probes of their host stellar populations. Information such as distance, metallicity, reddening, and age can be gleaned from their pulsation properties. Therefore, studying them in the nearest spiral galaxies M31 and M33 will yield important information about the early history of these galaxies. The main goals of this study are: 1) To investigate the Oosterhoff type of RR Lyrae stars in M31 and M33 and compare them with the Milky Way to better understand the formation of these galaxies. 2) To investigate the early formation history of these two galaxies through knowledge of their RR Lyrae stars. In order to achieve these goals, we have analyzed 10 fields in M31 and M33 (6 fields in M31 and 4 fields in M33) using archival imaging from the Hubble Space Telescope. Published data for M31, M33, and several M31 dwarf spheroidal galaxies are also used to study the global properties of RR Lyrae in these systems. The results are then compared with those in the Milky Way galaxy.

  15. Age and Mass Estimates for 41 Star Clusters in M33

    Institute of Scientific and Technical Information of China (English)

    Jun Ma; Xu Zhou; Jian-Sheng Chen

    2004-01-01

    In this second paper of our. series, we estimate the age of 41 star clusters,which were detected by Melnick & D'odorico in the nearby spiral galaxy M33, by comparing the integrated photometric measurements with theoretical stellar population synthesis models of Bruzual & Charlot. Also, we calculate the mass of these star clusters using the theoretical M/Lv ratio. The results show that, these star clusters formed continuously in M33 from ~ 7 × 106 - 1010 years and have masses between ~ 103 and 2 × 106 M . M33 frames were observed as a part of the BATC Multicolor Survey of the sky in 13 intermediate-band filters from 3800 to 10 000A.The relation between age and mass confirms that the sample star cluster masses systematically decrease from the oldest to the youngest.

  16. Gas and dust cooling along the major axis of M33 (HerM33es): ISO/LWS CII observations

    CERN Document Server

    Kramer, C; Garcia-Burillo, S; Relano, M; Aalto, S; Boquien, M; Braine, J; Buchbender, C; Gratier, P; Israel, F P; Nikola, T; Roellig, M; Verley, S; van der Werf, P; Xilouris, E M

    2013-01-01

    We aim to better understand the heating of the gas by observing the prominent gas cooling line [CII] at 158um in the low-metallicity environment of the Local Group spiral galaxy M33 at scales of 280pc. In particular, we aim at describing the variation of the photoelectric heating efficiency with galactic environment. In this unbiased study, we used ISO/LWS [CII] observations along the major axis of M33, in combination with Herschel PACS and SPIRE continuum maps, IRAM 30m CO 2-1 and VLA HI data to study the variation of velocity integrated intensities. The ratio of [CII] emission over the far-infrared continuum is used as a proxy for the heating efficiency, and models of photon-dominated regions are used to study the local physical densities, FUV radiation fields, and average column densities of the molecular clouds. The heating efficiency stays constant at 0.8% in the inner 4.5kpc radius of the galaxy where it starts to increase to reach values of ~3% in the outskirts at about 6kpc radial distance. The rise o...

  17. An extended star cluster at the outer edge of the spiral galaxy M33

    CERN Document Server

    Stonkute, Rima; Arimoto, Nobuo; Hasegawa, Takashi; Narbutis, Donatas; Tamura, Naoyuki; Jablonka, Pascale; Ohta, Kouji; Yamada, Yoshihiko

    2008-01-01

    We report a discovery of an extended globular-like star cluster, M33-EC1, at the outer edge of the spiral galaxy M33. The distance to the cluster is 890 kpc, and it lies at a 12.5 kpc projected distance from the center of M33. Old age (>~7 Gyr) and low metallicity ([M/H] <~ -1.4) are estimated on the basis of isochrone fits. Color-magnitude diagrams of stars, located in the cluster's area, photometric and structural parameters of the cluster are presented. Cluster's luminosity (M_V = -6.6) and half-light radius (r_h = 20.3 pc) are comparable to those of the extended globular clusters, discovered in more luminous Local Group galaxies, the Milky Way and M31. Extended globular clusters are suspected to be remnants of accreted dwarf galaxies, and the finding of such a cluster in the late-type dwarf spiral galaxy M33 would imply a complex merging history in the past.

  18. Molecular and atomic gas in the Local Group galaxy M 33

    NARCIS (Netherlands)

    Gratier, P.; Braine, J.; Rodriguez-Fernandez, N. J.; Schuster, K. F.; Kramer, C.; Xilouris, E. M.; Tabatabaei, F. S.; Henkel, C.; Corbelli, E.; Israel, F.; van der Werf, P. P.; Calzetti, D.; Garcia-Burillo, S.; Sievers, A.; Combes, F.; Wiklind, T.; Brouillet, N.; Herpin, F.; Bontemps, S.; Aalto, S.; Koribalski, B.; van der Tak, F.; Wiedner, M. C.; Röllig, M.; Mookerjea, B.

    2010-01-01

    We present high-resolution large-scale observations of the molecular and atomic gas in the Local Group galaxy M 33. The observations were carried out using the HEterodyne Receiver Array (HERA) at the 30 m IRAM telescope in the CO(2-1) line, achieving a resolution of 12” × 2.6 km s-1, enabling indivi

  19. Molecular and atomic gas in the Local Group galaxy M 33

    NARCIS (Netherlands)

    Gratier, P.; Braine, J.; Rodriguez-Fernandez, N. J.; Schuster, K. F.; Kramer, C.; Xilouris, E. M.; Tabatabaei, F. S.; Henkel, C.; Corbelli, E.; Israel, F.; Calzetti, D.; Garcia-Burillo, S.; Sievers, A.; Combes, F.; Wiklind, T.; Brouillet, N.; Herpin, F.; Bontemps, S.; Aalto, S.; Koribalski, B.; van der Tak, F.; Wiedner, M. C.; Roellig, M.; Mookerjea, B.; van der Werf, Paul P.

    2010-01-01

    We present high-resolution large-scale observations of the molecular and atomic gas in the Local Group galaxy M 33. The observations were carried out using the HEterodyne Receiver Array (HERA) at the 30 m IRAM telescope in the CO(2-1) line, achieving a resolution of 12 '' x 2.6 km s(-1), enabling in

  20. An updated catalog of M33 clusters and candidates: $UBVRI$ photometry, and some statistical results

    CERN Document Server

    Ma, Jun

    2012-01-01

    We present $UBVRI$ photometry for 392 star clusters and candidates in the field of M33, which are selected from the most recent star cluster catalog. In this catalog, the authors listed star clusters' parameters such as cluster positions, magnitudes and colors in the $UBVRIJHK_s$ filters, and so on. However, a large fraction of objects in this catalog do not have previously published photometry. Photometry is performed using archival images from the Local Group Galaxies Survey, which covers 0.8 deg$^2$ along the major axis of M33. Detailed comparisons show that, in general, our photometry is consistent with previous measurements. Positions (right ascension and declination) for some clusters are corrected here. Combined with previous literature, we constitute a large sample of M33 star clusters. Based on this cluster sample, we present some statistical results: none of the M33 youngest clusters ($\\sim 10^7$ yr) have masses approaching $10^5$ $M_{\\odot}$; roughly half the star clusters are consistent with the $...

  1. Point and Condensed Hα Sources in the Interior of M33

    Science.gov (United States)

    Moody, J. Ward; Hintz, Eric G.; Roming, Peter; Joner, Michael D.; Bucklein, Brian

    2017-01-01

    A variety of interesting objects such as Wolf-Rayet stars, tight OB associations, planetary nebula, x-ray binaries, etc. can be discovered as point or condensed sources in Hα surveys. How these objects distribute through a galaxy sheds light on the galaxy star formation rate and history, mass distribution, and dynamics. The nearby galaxy M33 is an excellent place to study the distribution of Hα-bright point sources in a flocculant spiral galaxy. We have reprocessed an archived WIYN continuum-subtracted Hα image of the inner 6.5' of the nearby galaxy M33 and, employing both eye and machine searches, have tabulated sources with a flux greater than 1 x 10-15 erg cm-2sec-1. We have identified 152 unresolved point sources and 122 marginally resolved condensed sources, 38 of which have not been previously cataloged. We present a map of these sources and discuss their probable identifications.

  2. Multi-epoch BVRI Photometry of Luminous Stars in M31 and M33

    Science.gov (United States)

    Martin, John C.; Humphreys, Roberta M.; pre="(">Minnesota Luminous Stars In Nearby Galaxies,

    2017-09-01

    We present the first four years of BVRI photometry from an on-going survey to annually monitor the photometric behavior of evolved luminous stars in M31 and M33. Photometry was measured for 199 stars at multiple epochs, including 9 classic Luminous Blue Variables (LBVs), 22 LBV candidates, 10 post-RGB A/F type hypergiants, and 18 B[e] supergiants. At all epochs, the brightness is measured in the V-band and at least one other band to a precision of 0.04-0.10 mag down to a limiting magnitude of 19.0-19.5. Thirty three stars in our survey exhibit significant variability, including at least two classic LBVs caught in S Doradus-type outbursts. A hyperlinked version of the photometry catalog is at http://go.uis.edu/m31m33photcat.

  3. Stochastic 2-D Models of Galaxy Disk Evolution. The Galaxy M33

    CERN Document Server

    Mineikis, Tadas

    2015-01-01

    We have developed a fast numerical 2-D model of galaxy disk evolution (resolved along the galaxy radius and azimuth) by adopting a scheme of parameterized stochastic self-propagating star formation. We explore the parameter space of the model and demonstrate its capability to reproduce 1-D radial profiles of the galaxy M33: gas surface density, surface brightness in the i and GALEX FUV passbands, and metallicity.

  4. The Early Spectral Evolution of the Classical Nova ASASSN-15th in M33

    Science.gov (United States)

    Wagner, R. Mark; Neric, Marko; Darnley, Matt J.; Williams, Steven; Starrfield, Sumner; Woodward, Charles E.; Prieto, Jose Luis

    2016-06-01

    During the course of the All Sky Automated Survey for SuperNovae (ASAS-SN) a new transient source designated ASASSN-15th was identified on images of the nearby galaxy M33 obtained with the 14 cm Brutus telescope in Haleakala, Hawaii on 2015 Dec 1.4 UT at V ~ 16.5 mag. Given the location of the transient in M33 and its apparent V magnitude at discovery, the implied absolute visual magnitude was about -8.5 mag suggesting that the transient was a new classical nova outburst in M33. Optical spectroscopy obtained by us on 2015 Dec 2.3 showed broad emission lines of Balmer, Fe II, and Na I D with P Cygni-type line profiles superposed on a blue continuum. The spectrum was consistent with a Fe II-type classical nova in M33 discovered early in the outburst. Subsequent spectra obtained by us on 2015 Dec 10.9 UT showed significant evolution since our first spectrum in that the deep P Cygni-type line profiles seen earlier were now extremely shallow or had almost completely disappeared with the emission component growing in strength. Additional emission lines from O I, Si II, and possibly He I were also present. We obtained optical spectroscopy of ASASSN-15th on 17 epochs between 2015 Dec 1 and 2016 Feb 11 UT with the 2.4 m Hiltner telescope (+OSMOS) of the MDM Observatory, the 2 m fully robotic Liverpool Telescope (+SPRAT), and the 2 x 8.4 m Large Binocular Telescope (+MODS). We will present our spectroscopy and discuss the early evolution of ASASSN-15th in the context of Galactic Fe II-class novae.

  5. On the mass and the density of stellar disk of M33

    CERN Document Server

    Saburova, A S

    2011-01-01

    The disk surface density of the nearby spiral galaxy M33 is estimated assuming that it is marginally stable against gravitational perturbations. For this purpose we used the radial profile of line-of-sight velocity dispersion of the disk planetary nebulae obtained by Ciardullo et al. (2004). The surface density profile we obtained is characterized by the radial scalelength which is close to the photometrical one and is in a good agreement with the rotation curve of M33 and with the mass-to-light ratio corresponding to the observed color indices. However at the galactocentric distance $r>7$ kpc the dynamical overheating of the disk remains quite possible. A thickness of the stellar disk of M33 should increase outwards. The dark halo mass exceeds the mass of the disk at $r>$ 7 kpc. The obtained radial profile of the disk surface density and the radial gradient of $O/H$ are used to calculate the effective oxygen yield $Y_{eff}$ in the frame of the instantaneous recycling approximation. It is shown that $Y_{eff}$...

  6. Dynamical signatures of a LCDM-halo and the distribution of the baryons in M33

    CERN Document Server

    Corbelli, Edvige; Zibetti, Stefano; Giovanardi, Carlo; Salucci, Paolo

    2014-01-01

    We map the neutral atomic gas content of M33 using high resolution VLA and GBT observations and fit a tilted ring model to determine the orientation of the extended gaseous disk and its rotation curve. The disk of M33 warps from 8 kpc outwards without substantial change of its inclination with respect to the line of sight. Rotational velocities rise steeply with radius in the inner disk, reaching 100 km/s in 4 kpc, then the rotation curve becomes more perturbed and flatter with velocities as high as 120-130 km/s out to 23 kpc. We derive the stellar mass surface density map of M33's optical disk, via pixel -SED fitting methods based on population synthesis models, which highlights variations in the mass-to-light ratio. The stellar mass surface further out is estimated from deep images of outer disk fields. Stellar and gas maps are then used in the dynamical analysis of the rotation curve to constrain the dark matter distribution which is relevant at all radii. A dark matter halo with a Navarro-Frenk-White dens...

  7. On the Neutral Hydrogen Filament Between M31 and M33

    Science.gov (United States)

    Lockman, Felix J.; Free, N.; Shields, J. C.

    2012-01-01

    In 2004, Braun & Thilker (B&T) reported the detection of extremely faint 21cm HI emission at the level log10(NH)=17.0 that formed a partial bridge about 200 kpc in extent between M31 and M33. This has been interpreted as the neutral component of a WHIM filament, or the remnant of a past encounter between the two galaxies. B&T used data from the Westerbork Synthesis Radio Telescope, operated as an array of single dishes, to obtain the necessary sensitivity, but at the expense of angular resolution ( 45'). Subsequently, Putman et al (2009) have questioned the existence of this filament, noting its absence from the immediate vicinity of M33 at the level log10(NH) 18 in data from Arecibo. We have reobserved much of the region between M31 and M33 using the Green Bank Telescope (GBT) at 9' resolution, with a 5-sigma sensitivity limit of log10(NHI) 18.0 and a few much deeper pointings. We detect HI lines consistent with the B&T results. In two locations the emission appears at log(NHI)>18.3, suggesting clumping in the otherwise diffuse gas. We estimate the mass of HI in the bridge, and show examples of the GBT's freedom from instrumental effects down to detection levels of log(NHI) 17.0. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under a cooperative agreement by Associated Universities, Inc.

  8. Millimeter and Submillimeter Excess Emission in M33 revealed by Planck and LABOCA

    CERN Document Server

    Hermelo, I; Lisenfeld, U; Verley, S; Kramer, C; Ruiz-Lara, T; Boquien, M; Xilouris, E M; Albrecht, M

    2016-01-01

    Previous studies have shown the existence of an excess of emission at submillimeter (submm) and millimeter (mm) wavelengths in the spectral energy distribution (SED) of many low-metallicity galaxies. The goal of the present study is to model separately the emission from the star forming (SF) component and the emission from the diffuse interstellar medium (ISM) in the nearby spiral galaxy M33. We decomposed the observed SED of M33 into its SF and diffuse components. Mid-infrared (MIR) and far-infrared (FIR) fluxes were extracted from Spitzer and Herschel data. At submm and mm wavelengths, we used ground-based observations from APEX to measure the emission from the SF component and data from the Planck space telescope to estimate the diffuse emission. Both components were separately fitted using radiation transfer models based on standard dust properties and a realistic geometry. Both modeled SEDs were combined to build the global SED of M33. In addition, the radiation field necessary to power the dust emission...

  9. Planetary nebulae in M33: probes of AGB nucleosynthesis and ISM abundances

    CERN Document Server

    Bresolin, Fabio; Vilchez, Jose M; Simon, Josh D; Rosolowsky, Erik

    2010-01-01

    We have obtained deep optical spectrophotometry of 16 planetary nebulae in M33, mostly located in the central two kpc of the galaxy, with the Subaru and Keck telescopes. We have derived electron temperatures and chemical abundances from the detection of the [OIII]4363 line for the whole sample. We have found one object with an extreme nitrogen abundance, 12+log(N/H)=9.20, accompanied by a large helium content. After combining our data with those available in the literature for PNe and HII regions, we have examined the behavior of nitrogen, neon, oxygen and argon in relation to each other, and as a function of galactocentric distance. We confirm the good correlation between Ne/H and O/H for PNe in M33. Ar/H is also found to correlate with O/H. This strengthens the idea that at the metallicity of the bright PNe analyzed in M33, which is similar to that found in the LMC, these elements have not been significantly modified during the dredge-up processes that take place during the AGB phase of their progenitor sta...

  10. The Star Formation History in The Far Outer Disc of M33

    CERN Document Server

    Barker, M K; Cole, A A; Ibata, R; Irwin, M; Lewis, G F; Smecker-Hane, T A; Tanvir, N R

    2010-01-01

    The outer regions of disc galaxies are becoming increasingly recognized as key testing sites for models of disc assembly and evolution. Important issues are the epoch at which the bulk of the stars in these regions formed and how discs grow radially over time. To address these issues, we use Hubble Space Telescope Advanced Camera for Surveys imaging to study the star formation history (SFH) of two fields at 9.1 and 11.6 kpc along M33's northern major axis. These fields lie at ~ 4 and 5 V-band disc scale-lengths and straddle the break in M33's surface brightness profile. The colour-magnitude diagrams (CMDs) reach the ancient main sequence turnoff with a signal-to-noise ratio of ~ 5. From detailed modelling of the CMDs, we find that the majority of stars in both fields combined formed at z < 1. The mean age in the inner field, S1, is ~ 3 +/- 1 Gyr and the mean metallicity is [M/H] ~ -0.5 +/- 0.2 dex. The star formation history of S1 unambiguously reveals how the inside-out growth previously measured for M33'...

  11. Outside-in stellar formation in the spiral galaxy M33?

    CERN Document Server

    Robles-Valdez, F; Peimbert, M

    2012-01-01

    We present and discuss results from chemical evolution models for M33. For our models we adopt a galactic formation with an inside-out scenario. The models are built to reproduce three observational constraints of the M33 disk: the radial distributions of: the total baryonic mass, the gas mass, and the O/H abundance. From observations, we find that the total baryonic mass profile in M33 has a double exponential behavior, decreasing exponentially for r 6 kpc due to the increase of the gas mass surface density. To adopt a concordant set of stellar and H II regions O/H values, we had to correct the later for the effect of temperature variations and O dust depletion. Our best model shows a good agreement with the observed the radial distributions of: the SFR, the stellar mass, C/H, N/H, Ne/H, Mg/H, Si/H, P/H, S/H, Ar/H, Fe/H,and Z. According to our model, the star formation efficiency is constant in time and space for r 6 kpc. The reduction of the SFR efficiency occurs earlier at higher r. While the galaxy follo...

  12. THE DEGENERACY OF M33 MASS MODELING AND ITS PHYSICAL IMPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Hague, P. R.; Wilkinson, M. I., E-mail: peter.hague@le.ac.uk, E-mail: miw6@le.ac.uk [University of Leicester, Leicester LE1 7RH (United Kingdom)

    2015-02-10

    The Local Group galaxy M33 exhibits a regular spiral structure and is close enough to permit high resolution analysis of its kinematics, making it an ideal candidate for rotation curve studies of its inner regions. Previous studies have claimed the galaxy has a dark matter halo with an Navarro-Frenk-White profile, based on statistical comparisons with a small number of other profiles. We apply a Bayesian method from our previous paper to place the dark matter density profile in the context of a continuous, and more general, parameter space. For a wide range of initial assumptions we find that models with inner log slope γ{sub in} < 0.9 are strongly excluded by the kinematics of the galaxy unless the mass-to-light ratio of the stellar components in the 3.6 μm band satisfies Y{sub 3.6} ≥ 2. Such a high Y{sub 3.6} is inconsistent with current modeling of the stellar population of M33. This suggests that M33 is a galaxy whose dark matter halo has not been significantly modified by feedback. We discuss possible explanations of this result, including ram pressure stripping during earlier interactions with M31.

  13. Millimeter and submillimeter excess emission in M 33 revealed by Planck and LABOCA

    Science.gov (United States)

    Hermelo, I.; Relaño, M.; Lisenfeld, U.; Verley, S.; Kramer, C.; Ruiz-Lara, T.; Boquien, M.; Xilouris, E. M.; Albrecht, M.

    2016-05-01

    Context. Previous studies have shown the existence of an excess of emission at submillimeter (submm) and millimeter (mm) wavelengths in the spectral energy distribution (SED) of many low-metallicity galaxies. The so-called "submm excess", whose origin remains unknown, challenges our understanding of the dust properties in low-metallicity environments. Aims: The goal of the present study is to model separately the emission from the star forming (SF) component and the emission from the diffuse interstellar medium (ISM) in the nearby spiral galaxy M 33 in order to determine whether both components can be well fitted using radiation transfer models or whether there is an excess of submm emission associated with one or both of them. Methods: We decomposed the observed SED of M 33 into its SF and diffuse components. Mid-infrared (MIR) and far-infrared (FIR) fluxes were extracted from Spitzer and Herschel data. At submm and mm wavelengths, we used ground-based observations from APEX to measure the emission from the SF component and data from the Planck space telescope to estimate the diffuse emission. Both components were separately fitted using radiation transfer models based on standard dust properties (i.e., emissivity index β = 2) and a realistic geometry. The large number of previous studies helped us to estimate the thermal radio emission and to constrain an important part of the input parameters of the models. Both modeled SEDs were combined to build the global SED of M 33. In addition, the radiation field necessary to power the dust emission in our modeling was compared with observations from GALEX, Sloan, and Spitzer. Results: Our modeling is able to reproduce the observations at MIR and FIR wavelengths, but we found a strong excess of emission at submm and mm wavelengths where the model expectations severely underestimate the LABOCA and Planck fluxes. We also found that the ultraviolet (UV) radiation escaping the galaxy is 70% higher than the model predictions

  14. Characterization of the C. elegans erlin homologue

    Directory of Open Access Journals (Sweden)

    Hoegg Maja B

    2012-01-01

    Full Text Available Abstract Background Erlins are highly conserved proteins associated with lipid rafts within the endoplasmic reticulum (ER. Biochemical studies in mammalian cell lines have shown that erlins are required for ER associated protein degradation (ERAD of activated inositol-1,4,5-trisphosphate receptors (IP3Rs, implying that erlin proteins might negatively regulate IP3R signalling. In humans, loss of erlin function appears to cause progressive intellectual disability, motor dysfunction and joint contractures. However, it is unknown if defects in IP3R ERAD are the underlying cause of this disease phenotype, whether ERAD of activated IP3Rs is the only function of erlin proteins, and what role ERAD plays in regulating IP3R-dependent processes in the context of an intact animal or embryo. In this study, we characterize the erlin homologue of the nematode Caenorhabditis elegans and examine erlin function in vivo. We specifically set out to test whether C. elegans erlin modulates IP3R-dependent processes, such as egg laying, embryonic development and defecation rates. We also explore the possibility that erlin might play a more general role in the ERAD pathway of C. elegans. Results We first show that the C. elegans erlin homologue, ERL-1, is highly similar to mammalian erlins with respect to amino acid sequence, domain structure, biochemical properties and subcellular location. ERL-1 is present throughout the C. elegans embryo; in adult worms, ERL-1 appears restricted to the germline. The expression pattern of ERL-1 thus only partially overlaps with that of ITR-1, eliminating the possibility of ERL-1 being a ubiquitous and necessary regulator of ITR-1. We show that loss of ERL-1 does not affect overall phenotype, or alter brood size, embryonic development or defecation cycle length in either wild type or sensitized itr-1 mutant animals. Moreover we show that ERL-1 deficient worms respond normally to ER stress conditions, suggesting that ERL-1 is not an

  15. UVOT Measurements of Dust and Star Formation in the SMC and M33

    CERN Document Server

    Hagen, Lea M Z; Gronwall, Caryl A; Hoversten, Erik A; Vargas, Angelica; Immler, Stefan

    2015-01-01

    When measuring star formation rates using ultraviolet light, correcting for dust extinction is a critical step. However, with the variety of dust extinction curves to choose from, the extinction correction is quite uncertain. Here, we use Swift/UVOT to measure the extinction curve for star-forming regions in the SMC and M33. We find that both the slope of the curve and the strength of the 2175 Angstrom bump vary across both galaxies. In addition, as part of our modeling, we derive a detailed recent star formation history for each galaxy.

  16. A Search for Miras in M33 Using Sparsely-Sampled Time Series Photometry

    Science.gov (United States)

    Yuan, Wenlong; Macri, Lucas M.; He, Shiyuan; Long, James; Huang, Jianhua

    2017-01-01

    The Mira Period-Luminosity relations (PLRs) at near- and mid-infrared wavelengths are promising distance indicators, with brighter absolute magnitudes than Cepheids, comparable PLR dispersions and ubiquitous presence in all galaxy types. We developed a semi-parametric Gaussian process periodogram method for sparsely-sampled Mira light curves and applied it to I-band observations of M33. We discovered more than 1800 Miras, which were subsequently classified using machine-learning techniques. We present an overview of the Gaussian process model, the Random Forest classifiers, and the resulting PLRs.

  17. Carbon and oxygen abundance gradients in NGC 300 and M33 from optical recombination lines

    Science.gov (United States)

    Toribio San Cipriano, L.; García-Rojas, J.; Esteban, C.; Bresolin, F.; Peimbert, M.

    2016-05-01

    We present deep spectrophotometry of several H II regions in the nearby low-mass spiral galaxies NGC 300 and M33. The data have been taken with Ultraviolet-Visual Echelle Spectrograph and Optical System for Imaging and low-Intermediate-Resolution Integrated Spectroscopy spectrographs attached to the 8-m Very Large Telescope and 10.4-m Gran Telescopio Canarias telescopes, respectively. We have derived precise values of the physical conditions for each object making use of several emission line-intensity ratios. In particular, we have obtained direct determinations of the electron temperature in all the observed objects. We detect pure recombination lines (RLs) of C II and O II in several of the H II regions, permitting to derive their C/H and C/O ratios. We have derived the radial abundance gradient of O for each galaxy making use of collisionally excited lines (CELs) and RLs, as well as the C and N gradients using RLs and CELs, respectively. We obtain the first determination of the C/H gradient of NGC 300 and improve its determination in the case of M33. In both galaxies, the C/H gradients are steeper than those of O/H, leading to negative C/O gradients. Comparing with similar results for other spiral galaxies, we find a strong correlation between the slope of the C/H gradient and MV. We find that some H II regions located close to the isophotal radius (R25) of NGC 300 and M33 show C/O ratios more similar to those typical of dwarf galaxies than those of H II regions in the discs of more massive spirals. This may be related to the absence of flattening of the gradients in the external parts of NGC 300 and M33. Finally, we find very similar N/H gradients in both galaxies and a fair correlation between the slope of the N/H gradient and MV comparing with similar data for a sample of spiral galaxies.

  18. Positions and Spectral Energy Distributions of 41 Star Clusters in M33

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    We present accurate positions and multi-color photometry for 41 starclusters detected by Melnick & D'odorico in the nearby spiral galaxy M33 as a partof the BATC Color Survey of the sky in 13 intermediate-band filters from 3800to 10000A. The coordinates of the clusters are found from the HST Guide StarCatalog. By aperture photometry, we obtain the spectral energy distributions ofthe clusters. Using the relations between the BATC intermediate-band system andUBVRI broadband system, we derive their V magnitudes and B - V colors andfind that most of them are blue, which is consistent with previous findings.

  19. A Turbulent Origin for Flocculent Spiral Structure in Galaxies: II. Observations and Models of M33

    CERN Document Server

    Elmegreen, B G; Elmegreen, D M; Cuillandre, J C; Elmegreen, Bruce G.; Leitner, Samuel N.; Elmegreen, Debra Meloy; Cuillandre, Jean-Charles

    2003-01-01

    Fourier transform power spectra of azimuthal scans of the optical structure of M33 are evaluated for B, V, and R passbands and fit to fractal models of continuum emission with superposed star formation. Power spectra are also determined for Halpha. The best models have intrinsic power spectra with 1D slopes of around -0.7pm0.7, significantly shallower than the Kolmogorov spectrum (slope =-1.7) but steeper than pure noise (slope=0). A fit to the power spectrum of the flocculent galaxy NGC 5055 gives a steeper slope of around -1.5pm0.2, which could be from turbulence. Both cases model the optical light as a superposition of continuous and point-like stellar sources that follow an underlying fractal pattern. Foreground bright stars are clipped in the images, but they are so prominent in M33 that even their residual affects the power spectrum, making it shallower than what is intrinsic to the galaxy. A model consisting of random foreground stars added to the best model of NGC 5055 fits the observed power spectrum...

  20. The Herschel view of HII regions in M 33 (HERM33ES)

    Science.gov (United States)

    Verley, S.; Relaño, M.; Kramer, C.; Xilouris, E. M.; Boquien, M.; Calzetti, D.; Combes, F.; Buchbender, C.; Braine, J.; Quintana-Lacaci, G.; Tabatabaei, F. S.; Lord, S.; Israel, F.; Stacey, G.; van der Werf, P.

    2010-12-01

    Within the framework of the HERM33ES Key Project (Kramer et al. 2010), using the high resolution and sensitivity of the Herschel photometric data, we study the compact emission in the Local Group spiral galaxy M 33. We present a catalogue of 159 compact emission sources in M 33 identified by SExtractor in the 250 μm SPIRE band which is the one that provides the best spatial resolution. We measure fluxes at 24 μm and Hα for those 159 extracted sources. We find a very strong Pearson correlation coefficient with the MIPS 24 μm emission (r24 = 0.94) and a rather strong correlation with the Hα emission, although with more scatter (rHα = 0.83). Due to the very strong link between the 250 μm compact emission and the 24 μm and Hα emissions, by recovering the star formation rate from standard recipes for H II regions, we are able to provide star formation rate calibrations based on the 250 μm compact emission alone. Finally, the morphological study of a set of three Hα shells shows that there is a displacement between far-ultraviolet and the SPIRE bands, while the Hα structure is in general much more coincident with the cool dust.

  1. Properties of compact 250 \\mu m emission and HII regions in M33 (HERM33ES)

    CERN Document Server

    Verley, S; Kramer, C; Xilouris, E M; Boquien, M; Calzetti, D; Combes, F; Buchbender, C; Braine, J; Quintana-Lacaci, G; Tabatabaei, F S; Lord, S; Israel, F; Stacey, G; van der Werf, P

    2010-01-01

    Within the framework of the HERM33ES Key Project, using the high resolution and sensitivity of the Herschel photometric data, we study the compact emission in the Local Group spiral galaxy M33 to investigate the nature of the compact SPIRE emission sources. We extracted a catalogue of sources at 250um in order to investigate the nature of this compact emission. Taking advantage of the unprecedented Herschel resolution at these wavelengths, we also focus on a more precise study of some striking Halpha shells in the northern part of the galaxy. We present a catalogue of 159 compact emission sources in M33 identified by SExtractor in the 250um SPIRE band that is the one that provides the best spatial resolution. We also measured fluxes at 24um and Halpha for those 159 extracted sources. The morphological study of the shells also benefits from a multiwavelength approach including Halpha, far-UV from GALEX, and infrared from both Spitzer IRAC 8um and MIPS 24um in order to make comparisons. For the 159 compact sour...

  2. Detection of the second eclipsing high mass X-ray binary in M 33

    CERN Document Server

    Pietsch, W; Gaetz, T J; Hartman, J D; Plucinsky, P P; Tüllmann, R; Williams, B F; Shporer, A; Mazeh, T; Pannuti, T G

    2008-01-01

    Chandra data of the X-ray source [PMH2004] 47 were obtained in the ACIS Survey of M 33 (ChASeM33) in 2006. During one of the observations, the source varied from a high state to a low state and back, in two other observations it varied from a low state to respectively intermediate states. These transitions are interpreted as eclipse ingress and egresses of a compact object in a high mass X-ray binary system. The phase of mid eclipse is given by HJD 2453997.476+-0.006, the eclipse half angle is 30.6+-1.2 degree. Adding XMM-Newton observations of [PMH2004] 47 in 2001 we determine the binary period to be 1.732479+-0.000027 d. This period is also consistent with ROSAT HRI observations of the source in 1994. No short term periodicity compatible with a rotation period of the compact object is detected. There are indications for a long term variability similar to that detected for Her X-1. During the high state the spectrum of the source is hard (power law spectrum with photon index ~0.85) with an unabsorbed luminos...

  3. Carbon and oxygen abundance gradients in NGC300 and M33 from optical recombination lines

    CERN Document Server

    Cipriano, L Toribio San; Esteban, C; Bresolin, F; Peimbert, M

    2016-01-01

    We present deep spectrophotometry of several Hii regions in the nearby low-mass spiral galaxies NGC 300 and M33. The data have been taken with UVES and OSIRIS spectrographs attached to the 8m VLT and 10.4m GTC telescopes, respectively. We have derived precise values of the physical conditions for each object making use of several emission line-intensity ratios. In particular, we have obtained direct determinations of the electron temperature in all the observed objects. We detect pure recombination lines (RLs) of Cii and Oii in several of the Hii regions, permitting to derive their C/H and C/O ratios. We have derived the radial abundance gradient of O for each galaxy making use of collisionally excited lines (CELs) and RLs, as well as the C and N gradients using RLs and CELs, respectively. We obtain the first determination of the C/H gradient of NGC 300 and improve its determination in the case of M33. In both galaxies, the C/H gradients are steeper that those of O/H, leading to negative C/O gradients. Compar...

  4. Molecular and Atomic Gas in the Local Group Galaxy M33

    CERN Document Server

    Gratier, P; Rodriguez-Fernandez, N J; Schuster, K F; Kramer, C; Xilouris, E M; Tabatabaei, F S; Henkel, C; Corbelli, E; Israel, F; van der Werf, P P; Calzetti, D; Garcia-Burillo, S; Sievers, A; Combes, F; Wiklind, T; Brouillet, N; Herpin, F; Bontemps, S; Aalto, S; Koribalski, B; van der Tak, F; Wiedner, M C; Roellig, M; Mookerjea, B

    2010-01-01

    We present high resolution large scale observations of the molecular and atomic gas in the Local Group Galaxy M33. The observations were carried out using the HERA multibeam receiver at the 30m IRAM telescope in the CO(2-1) line achieving a resolution of 12" x 2.6km/s, enabling individual Giant Molecular Clouds (GMCs) to be resolved. The observed region is 650 square arcminutes mainly along the major axis and out to a radius of 8.5 kpc, and covers entirely the 2' x40' radial strip observed with the HIFI and PACS Spectrometers as part of the HERM33ES Herschel key program. The achieved sensitivity in main beam temperature is 20-50mK at 2.6km/s velocity resolution. The CO(2-1) luminosity of the observed region is 1.7+/-0.1x10^7 Kkm/s pc^2 and is estimated to be 2.8+/-0.3x10^7 Kkm/s pc^2 for the entire galaxy, corresponding to H_2 masses of 1.9x10^8 M_sun and 3.3x10^8 M_sun respectively (including He), calculated with a NH2/ICO twice the Galactic value due to the half-solar metallicity of M33. HI 21 cm VLA archiv...

  5. Deriving physical parameters of unresolved star clusters IV. The M33 star cluster system

    CERN Document Server

    de Meulenaer, P; Mineikis, T; Vansevičius, V

    2015-01-01

    Context. When trying to derive the star cluster physical parameters of the M33 galaxy using broad-band unresolved ground-based photometry, previous studies mainly made use of simple stellar population models, shown in the recent years to be oversimplified. Aims. In this study, we aim to derive the star cluster physical parameters (age, mass, and extinction; metallicity is assumed to be LMC-like for clusters with age below 1\\,Gyr and left free for older clusters) of this galaxy using models that take stochastic dispersion of cluster integrated colors into account. Methods. We use three recently published M33 catalogs of cluster optical broad-band photometry in standard $UBVRI$ and in CFHT/MegaCam $u^{*}g'r'i'z'$ photometric systems. We also use near-infrared $JHK$ photometry that we derive from deep 2MASS images. We derive the cluster parameters using a method that takes into account the stochasticity problem, presented in previous papers of this series. Results. The derived differential age distribution of th...

  6. A Spectroscopic Survey of Massive Stars in M31 and M33

    Science.gov (United States)

    Massey, Philip; Neugent, Kathryn F.; Smart, Brianna M.

    2016-09-01

    We describe our spectroscopic follow-up to the Local Group Galaxy Survey (LGGS) photometry of M31 and M33. We have obtained new spectroscopy of 1895 stars, allowing us to classify 1496 of them for the first time. Our study has identified many foreground stars, and established membership for hundreds of early- and mid-type supergiants. We have also found nine new candidate luminous blue variables and a previously unrecognized Wolf-Rayet star. We republish the LGGS M31 and M33 catalogs with improved coordinates, and including spectroscopy from the literature and our new results. The spectroscopy in this paper is responsible for the vast majority of the stellar classifications in these two nearby spiral neighbors. The most luminous (and hence massive) of the stars in our sample are early-type B supergiants, as expected; the more massive O stars are more rare and fainter visually, and thus mostly remain unobserved so far. The majority of the unevolved stars in our sample are in the 20-40 M ⊙ range. The spectroscopic observations reported here were obtained at the MMT Observatory, a joint facility of the University of Arizona and the Smithsonian Institution. MMT telescope time was granted by NOAO, through the Telescope System Instrumentation Program (TSIP). TSIP is funded by the National Science Foundation. This paper uses data products produced by the OIR Telescope Data Center, supported by the Smithsonian Astrophysical Observatory.

  7. Detection of the Second Eclipsing High-Mass X-Ray Binary in M 33

    Science.gov (United States)

    Pietsch, Wolfgang; Haberl, Frank; Gaetz, Terrance J.; Hartman, Joel D.; Plucinsky, Paul P.; Tüllmann, Ralph; Williams, Benjamin F.; Shporer, Avi; Mazeh, Tsevi; Pannuti, Thomas G.

    2009-03-01

    Chandra data of the X-ray source [PMH2004] 47 were obtained in the ACIS Survey of M 33 (ChASeM33) in 2006. During one of the observations, the source varied from a high state to a low state and back, in two other observations it varied from a low state to respectively intermediate states. These transitions are interpreted as eclipse ingresses and egresses of a compact object in a high-mass X-ray binary (HMXB) system. The phase of mideclipse is given by HJD 245 3997.476 ± 0.006, the eclipse half angle is 30fdg6 ± 1fdg2. Adding XMM-Newton observations of [PMH2004] 47 in 2001 we determine the binary period to be 1.732479 ± 0.000027 days. This period is also consistent with ROSAT HRI observations of the source in 1994. No short-term periodicity compatible with a rotation period of the compact object is detected. There are indications for a long-term variability similar to that detected for Her X-1. During the high state the spectrum of the source is hard (power-law spectrum with photon index ~0.85) with an unabsorbed luminosity of 2 ×1037 erg s-1 (0.2-4.5 keV). We identify as an optical counterpart a V ~ 21.0 mag star with T eff>19000 K, log(g)>2.5. The Canada-France-Hawaii Telescope optical light curves for this star show an ellipsoidal variation with the same period as the X-ray light curve. The optical light curve together with the X-ray eclipse can be modeled by a compact object with a mass consistent with a neutron star or a black hole in an HMXB. However, the hard power-law X-ray spectrum favors a neutron star as the compact object in this second eclipsing X-ray binary in M 33. Assuming a neutron star with a canonical mass of 1.4 M sun and the best-fit companion temperature of 33,000 K, a system inclination i = 72° and a companion mass of 10.9 M sun are implied.

  8. Crystal chemistry of sartorite homologues and related sulfosalts

    DEFF Research Database (Denmark)

    Berlepsch, Peter; Makovicky, Emil; Balic-Zunic, Tonci

    2001-01-01

    sartorite homologues, sulfosalt, crystal chemistry, coordination polyhedra, bond-pairs, crankshaft chains......sartorite homologues, sulfosalt, crystal chemistry, coordination polyhedra, bond-pairs, crankshaft chains...

  9. The HI distribution in the outskirts of M33 with the ALFALFA survey

    CERN Document Server

    Grossi, M; Corbelli, E

    2008-01-01

    Spiral galaxies appear to be dynamical systems whose disks are still forming at the current epoch and which continue to accrete mass. The presence of extraplanar gas in spirals indicates that galactic halos can contain at least part of the material needed to fuel the star formation activity in their disks. Here we present the analysis of the ALFALFA survey data in the region of M33 aimed at searching high velocity clouds around this Local Group galaxy. We find a varied population of HI clouds with masses ranging between 4 x 10^4 and few times 10^6 M_sun. We also detect an extended HI complex at anomalous velocities, whose extragalactic nature cannot be firmly established. We estimate that the total amount of neutral hydrogen mass associated to these clouds is around 10^7 M_sun.

  10. HST/COS Observations of Ionized Gas Accretion at the Disk–Halo Interface of M33

    Science.gov (United States)

    Zheng, Y.; Peek, J. E. G.; Werk, J. K.; Putman, M. E.

    2017-01-01

    We report the detection of accreting ionized gas at the disk–halo interface of the nearby galaxy M33. We analyze Hubble Space Telescope/Cosmic Origins Spectrograph absorption-line spectra of seven ultraviolet-bright stars evenly distributed across the disk of M33. We find Si iv absorption components consistently redshifted relative to the bulk M33's ISM absorption along all the sightlines. The Si iv detection indicates an enriched, disk-wide, ionized gas inflow toward the disk. This inflow is most likely multi-phase as the redshifted components can also be observed in ions with lower ionization states (e.g., S ii, P ii, Fe ii, Si ii). Kinematic modeling of the inflow is consistent with an accreting layer at the disk–halo interface of M33, which has an accretion velocity of {110}-20+15 {km} {{{s}}}-1 at a distance of {1.5}-1.0+1.0 kpc above the disk. The modeling indicates a total mass of ∼3.9 × 107 M⊙ for the accreting material at the disk–halo interface on the near side of the M33 disk, with an accretion rate of ∼2.9 M⊙ yr‑1. The high accretion rate and the level of metal enrichment suggest the inflow is likely to be the fallback of M33 gas from a galactic fountain and/or the gas pulled loosed during a close interaction between M31 and M33. Our study of M33 is the first to unambiguously reveal the existence of a disk-wide, ionized gas inflow beyond the Milky Way, providing a better understanding of gas accretion in the vicinity of a galaxy disk.

  11. Identification and analysis of cation channel homologues in human pathogenic fungi.

    Directory of Open Access Journals (Sweden)

    David L Prole

    Full Text Available Fungi are major causes of human, animal and plant disease. Human fungal infections can be fatal, but there are limited options for therapy, and resistance to commonly used anti-fungal drugs is widespread. The genomes of many fungi have recently been sequenced, allowing identification of proteins that may become targets for novel therapies. We examined the genomes of human fungal pathogens for genes encoding homologues of cation channels, which are prominent drug targets. Many of the fungal genomes examined contain genes encoding homologues of potassium (K(+, calcium (Ca(2+ and transient receptor potential (Trp channels, but not sodium (Na(+ channels or ligand-gated channels. Some fungal genomes contain multiple genes encoding homologues of K(+ and Trp channel subunits, and genes encoding novel homologues of voltage-gated K(v channel subunits are found in Cryptococcus spp. Only a single gene encoding a homologue of a plasma membrane Ca(2+ channel was identified in the genome of each pathogenic fungus examined. These homologues are similar to the Cch1 Ca(2+ channel of Saccharomyces cerevisiae. The genomes of Aspergillus spp. and Cryptococcus spp., but not those of S. cerevisiae or the other pathogenic fungi examined, also encode homologues of the mitochondrial Ca(2+ uniporter (MCU. In contrast to humans, which express many K(+, Ca(2+ and Trp channels, the genomes of pathogenic fungi encode only very small numbers of K(+, Ca(2+ and Trp channel homologues. Furthermore, the sequences of fungal K(+, Ca(2+, Trp and MCU channels differ from those of human channels in regions that suggest differences in regulation and susceptibility to drugs.

  12. Spitzer Observations of M33 and the Hot Star, H II Region Connection

    CERN Document Server

    Rubin, Robert H; Colgan, Sean W J; Dufour, Reginald J; Brunner, Gregory; McNabb, Ian A; Pauldrach, Adalbert W A; Erickson, Edwin F; Haas, Michael R; Citron, Robert I

    2008-01-01

    We have observed emission lines of [S IV] 10.51, H(7-6) 12.37, [Ne II] 12.81, [Ne III] 15.56, and [S III] 18.71 um in a number of extragalactic H II regions with the Spitzer Space Telescope. A previous paper presented our data and analysis for the substantially face-on spiral galaxy M83. Here we report our results for the local group spiral galaxy M33. The nebulae selected cover a wide range of galactocentric radii (R_G). The observations were made with the Infrared Spectrograph with the short wavelength, high resolution module. The above set of five lines is observed cospatially, thus permitting a reliable comparison of the fluxes. From the measured fluxes, we determine the ionic abundance ratios including Ne++/Ne+, S3+/S++, and S++/Ne+ and find that there is a correlation of increasingly higher ionization with larger R_G. By sampling the dominant ionization states of Ne (Ne+, Ne++) and S (S++, S3+) for H II regions, we can estimate the Ne/H, S/H, and Ne/S ratios. We find from linear least-squares fits that ...

  13. The Scale Dependence of the Molecular Gas Depletion Time in M33

    CERN Document Server

    Schruba, Andreas; Walter, Fabian; Sandstrom, Karin; Rosolowsky, Erik

    2010-01-01

    We study the Local Group spiral galaxy M33 to investigate how the observed scaling between the (kpc-averaged) surface density of molecular gas (\\Sigma_H2) and recent star formation rate (\\Sigma_SFR) relates to individual star-forming regions. To do this, we measure the ratio of CO emission to extinction-corrected Halpha emission in apertures of varying sizes centered both on peaks of CO and Halpha emission. We parameterize this ratio as a molecular gas (H_2) depletion time (\\tau_dep). On large (kpc) scales, our results are consistent with a molecular star formation law (Sigma_SFR \\sim Sigma_H2^b) with b \\sim 1.1 - 1.5 and a median \\tau_dep \\sim 1 Gyr, with no dependence on type of region targeted. Below these scales, \\tau_dep is a strong function of adopted angular scale and the type of region that is targeted. Small (\\lesssim 300pc) apertures centered on CO peaks have very long \\tau_dep (i.e., high CO-to-Halpha flux ratio) and small apertures targeted toward Halpha peaks have very short \\tau_dep. This implie...

  14. The metallicity gradient of M 33: chemical abundances of HII regions

    CERN Document Server

    Magrini, L; Mampaso, A; Corradi, R L M; Leisy, P

    2007-01-01

    We present spectroscopic observations of a sample of 72 emission-line objects, including mainly HII regions, in the spiral galaxy M 33. Spectra were obtained with the multi-object, wide field spectrograph AF2/WYFFOS at the 4.2m WHT telescope. Line intensities, extinction, and electron density were determined for the whole sample of objects. The aim of the present work was to derive chemical and physical parameters of a set of HII regions, and from them the metallicity gradient. Electron temperatures and chemical abundances were derived for the 14 HII regions where both [OII] and [OIII] emission line fluxes were measured, including the electron temperature sensitive emission line [OIII] 436.3 nm and in a few cases [NII] 575.5 nm. The ionization correction factor (ICF) method was used to derive the total chemical abundances. The presence of abundance gradients was inferred from the radial behaviour of several emission-line ratios, and accurately measured from chemical abundances directly derived in 14 HII regio...

  15. Three supernova shells around a young star cluster in M33

    CERN Document Server

    Camps-Fariña, Artemi; Font, Joan; Borlaff, Alejandro; Zaragoza-Cardiel, Javier; Amram, Philippe

    2016-01-01

    Using a specialized technique sensitive to the presence of expanding ionized gas we have detected a set of three concentric expanding shells in an HII region in the nearby spiral galaxy M33. After mapping the kinematics in H{\\alpha} with Fabry-Perot spectroscopy we used slit spectra to measure the intensities of the [SII] doublet at {\\lambda}{\\lambda} 671.9, 673.1 nm and the [NII] doublet at {\\lambda}{\\lambda} 645.8, 658.3 nm to corroborate the kinematics and apply diagnostic tests using line ratios. These showed that the expanding shells are shock dominated as would be the case if they had originated with supernova explosions. Estimating their kinetic energies we find fairly low values, indicating a fairly advanced stage of evolution. We obtain density, mass and parent star mass estimates, which, along with the kinetic energies, are inconsistent with the simplest models of shock-interstellar medium interaction. We propose that the presence and properties of an inhomogeneous medium offer a scenario which can ...

  16. Testing the radial dependence of dark matter distribution in M33

    CERN Document Server

    Fune, Ernesto Lopez; Corbelli, Edvige

    2016-01-01

    The stellar and gaseous mass distributions, as well as the extended rotation curve in the nearby galaxy M33 are used to derive the radial distribution of dark matter density in the halo and to test cosmological models of galaxy formation and evolution. Two methods are examined to constrain dark mass density profiles. The first one deals directly with the fitting of the rotation curve data in the range of galacto-centric distances $0.24\\,\\text{kpc}\\leq r\\leq22.72\\,\\text{kpc}$. As found in a previous paper Corbelli 2014 et. al. and using the results of recent collisionless $\\Lambda-$CDM numerical simulations, we confirm that the Navarro-Frenkel-White (NFW) dark matter profile provides a better fit to the rotation curve data than the cored Burkert (URC) profile. The second method relies on the local equation of centrifugal equilibrium and on the rotation curve slope. In the aforementioned range of distances, we fit an empirical velocity profile using a function which has a rational dependence on the radius. Foll...

  17. Var C: Long-term photometric and spectral variability of an LBV in M33

    CERN Document Server

    Burggraf, B; Bomans, D J; Henze, M; Meusinger, H; Sholukhova, O; Zharova, A; Pellerin, A; Becker, A

    2015-01-01

    So far the highly unstable phase of luminous blue variables (LBVs) has not been understood well. It is still uncertain why and which massive stars enter this phase. Investigating the variabilities by looking for a possible regular or even (semi-)periodic behaviour could give a hint at the underlying mechanism for these variations and might answer the question of where these variabilities originate. Finding out more about the LBV phase also means understanding massive stars better in general, which have (e.g. by enriching the ISM with heavy elements, providing ionising radiation and kinetic energy) a strong and significant influence on the ISM, hence also on their host galaxy. Photometric and spectroscopic data were taken for the LBV Var C in M33 to investigate its recent status. In addition, scanned historic plates, archival data, and data from the literature were gathered to trace Var C's behaviour in the past. Its long-term variability and periodicity was investigated. Our investigation of the variability i...

  18. A VLA Search for Radio Signals from M31 and M33

    Science.gov (United States)

    Gray, Robert H.; Mooley, Kunal

    2017-03-01

    Observing nearby galaxies would facilitate the search for artificial radio signals by sampling several billions of stars simultaneously, but few efforts have been made to exploit this opportunity. An added attraction is that the Milky Way is the second largest member of the Local Group, so our galaxy might be a probable target for hypothetical broadcasters in nearby galaxies. We present the first relatively high spectral resolution (radio signals of complete galaxies in the Local Group with the Jansky VLA, observing the galaxies M31 (Andromeda) and M33 (Triangulum)—the first and third largest members of the group, respectively—sampling more stars than any prior search of this kind. We used 122 Hz channels over a 1 MHz spectral window in the target galaxy velocity frame of reference, and 15 Hz channels over a 125 kHz window in our local standard of rest. No narrowband signals were detected above a signal-to-noise ratio of 7, suggesting the absence of continuous narrowband flux greater than approximately 0.24 and 1.33 Jy in the respective spectral windows illuminating our part of the Milky Way during our observations in 2014 December and 2015 January. This is also the first study in which the upgraded VLA has been used for SETI.

  19. Measuring star formation with resolved observations: the test case of M33

    CERN Document Server

    Boquien, M; Aalto, S; Boselli, A; Braine, J; Buat, V; Combes, F; Israel, F; Kramer, C; Lord, S; Relano, M; Rosolowsky, E; Stacey, G; Tabatabaei, F; van der Tak, F; van der Werf, P; Verley, S; Xilouris, M

    2015-01-01

    Context. Measuring star formation at a local scale is important to constrain star formation laws. Yet, it is not clear whether and how the measure of star formation is affected by the spatial scale at which a galaxy is observed. Aims. We want to understand the impact of the resolution on the determination of the spatially resolved star formation rate (SFR) and other directly associated physical parameters such as the attenuation. Methods. We have carried out a multi-scale, pixel-by-pixel study of the nearby galaxy M33. Assembling FUV, Halpha, 8, 24, 70, and 100 micron maps, we have systematically compared the emission in individual bands with various SFR estimators from a resolution of 33 pc to 2084 pc. Results. We have found that there are strong, scale-dependent, discrepancies up to a factor 3 between monochromatic SFR estimators and Halpha+24 micron. The scaling factors between individual IR bands and the SFR show a strong dependence on the spatial scale and on the intensity of star formation. Finally, str...

  20. HST/COS Observations of Ionized Gas Accretion at the Disk-halo Interface of M33

    CERN Document Server

    Zheng, Y; Werk, J K; Putman, M E

    2016-01-01

    We report the detection of accreting ionized gas at the disk-halo interface of the nearby galaxy M33. We analyze HST/COS absorption-line spectra of seven ultraviolet-bright stars evenly distributed across the disk of M33. We find Si IV absorption components consistently redshifted relative to the bulk M33's ISM absorption along all the sightlines. The Si IV detection indicates an enriched, disk-wide, ionized gas inflow toward the disk. This inflow is most likely multi-phase as the redshifted components can also be observed in ions with lower ionization states (e.g., S II, P II, Fe II, Si II). Kinematic modeling of the inflow is consistent with an accreting layer at the disk-halo interface of M33, which has an accretion velocity of 110$^{+15}_{-20}$ km s$^{-1}$ at a distance of 1.5$^{+1.0}_{-1.0}$ kiloparsec above the disk. The modeling indicates a total mass of $\\sim3.9\\times10^7$ M$_{\\odot}$ for the accreting material at the disk-halo interface on the near side of the M33 disk , with an accretion rate of $\\s...

  1. Star formation in M 33: the radial and local relations with the gas

    Science.gov (United States)

    Verley, S.; Corbelli, E.; Giovanardi, C.; Hunt, L. K.

    2010-02-01

    Aims: In the Local Group spiral galaxy M 33, we investigate the correlation between the star formation rate (SFR) surface density, Σ_SFR, and the gas density Σ_gas (molecular, atomic, and total). We also explore whether there are other physical quantities, such as the hydrostatic pressure and dust optical depth, which establish a good correlation with Σ_SFR. Methods: We use the Hα, far-ultraviolet (FUV), and bolometric emission maps to infer the SFR locally at different spatial scales, and in radial bins using azimuthally averaged values. Most of the local analysis is done using the highest spatial resolution allowed by gas surveys, 180 pc. The Kennicutt-Schmidt (KS) law, Σ_SFR ∝ Σ_gas^n is analyzed by three statistical methods. Results: At all spatial scales, with Hα emission as a SFR tracer, the KS indices n are always steeper than those derived with the FUV and bolometric emissions. We attribute this to the lack of Hα emission in low luminosity regions where most stars form in small clusters with an incomplete initial mass function at their high mass end. For azimuthally averaged values the depletion timescale for the molecular gas is constant, and the KS index is n_H_2=1.1 ±0.1. Locally, at a spatial resolution of 180 pc, the correlation between Σ_SFR and Σ_gas is generally poor, even though it is tighter with the molecular and total gas than with the atomic gas alone. Considering only positions where the CO J=1-0 line is above the 2-σ detection threshold and taking into account uncertainties in Σ_H_2 and Σ_SFR, we obtain a steeper KS index than obtained with radial averages: n_H_2=2.22 ±0.07 (for FUV and bolometric SFR tracers), flatter than that relative to the total gas (n_Htot=2.59 ±0.05). The gas depletion timescale is therefore larger in regions of lower Σ_SFR. Lower KS indices (n_H_2=1.46 ±0.34 and n_H_2=1.12) are found using different fitting techniques, which do not account for individual position uncertainties. At coarser spatial

  2. Molecular and atomic gas in the Local Group galaxy M 33

    Science.gov (United States)

    Gratier, P.; Braine, J.; Rodriguez-Fernandez, N. J.; Schuster, K. F.; Kramer, C.; Xilouris, E. M.; Tabatabaei, F. S.; Henkel, C.; Corbelli, E.; Israel, F.; van der Werf, P. P.; Calzetti, D.; Garcia-Burillo, S.; Sievers, A.; Combes, F.; Wiklind, T.; Brouillet, N.; Herpin, F.; Bontemps, S.; Aalto, S.; Koribalski, B.; van der Tak, F.; Wiedner, M. C.; Röllig, M.; Mookerjea, B.

    2010-11-01

    We present high-resolution large-scale observations of the molecular and atomic gas in the Local Group galaxy M 33. The observations were carried out using the HEterodyne Receiver Array (HERA) at the 30 m IRAM telescope in the CO(2-1) line, achieving a resolution of 12” × 2.6 km s-1, enabling individual giant molecular clouds (GMCs) to be resolved. The observed region is 650 square arcminutes mainly along the major axis and out to a radius of 8.5 kpc, and covers entirely the 2' × 40' radial strip observed with the HIFI and PACS Spectrometers as part of the HERM33ES Herschel key program. The achieved sensitivity in main-beam temperature is 20-50 mK at 2.6 km s-1 velocity resolution. The CO(2-1) luminosity of the observed region is 1.7±0.1 × 107 K km s-1 pc2 and is estimated to be 2.8±0.3 × 107 K km s-1 pc2 for the entire galaxy, corresponding to H2 masses of 1.9 × 108 Msun and 3.3 × 108 Msun respectively (including He), calculated with N(H2)/ICO(1-0) twice the Galactic value due to the half-solar metallicity of M 33. The H i 21 cm VLA archive observations were reduced, and the mosaic was imaged and cleaned using the multi-scale task in the CASA software package, yielding a series of datacubes with resolutions ranging from 5” to 25”. The H i mass within a radius of 8.5 kpc is estimated to be 1.4 × 109 Msun. The azimuthally averaged CO surface brightness decreases exponentially with a scale length of 1.9±0.1 kpc whereas the atomic gas surface density is constant at ΣH I = 6±2 Msun pc-2 deprojected to face-on. For an N(H2)/ICO(1-0) conversion factor twice that of the Milky Way, the central kiloparsec H2 surface density is ΣH2 = 8.5±0.2 Msun pc-2. The star formation rate per unit molecular gas (SF efficiency, the rate of transformation of molecular gas into stars), as traced by the ratio of CO to Hα and FIR brightness, is constant with radius. The SFE, with a N(H2)/ICO(1-0) factor twice galactic, appears 2-4 times greater than for large spiral

  3. ISO Mid-Infrared Observations of Giant HII Regions in M33

    Science.gov (United States)

    Skelton, B. P.; Waller, W. H.; Hodge, P. W.; Boulanger, F.; Cornett, R. H.; Fanelli, M. N.; Lequeux, J.; Stecher, T. P.; Viallefond, F.; Hui, Y.

    1999-01-01

    We present Infrared Space Observatory Camera (ISOCAM) Circular Variable Filter scans of three giant HII regions in M33. IC 133, NGC 595, and CC 93 span a wide range of metallicity, luminosity, nebular excitation, and infrared excess; three other emission regions (CC 43, CC 99, and a region to the northeast of the core of NGC 595) are luminous enough in the mid-infrared to be detected in the observed fields. ISOCAM CVF observations provide spatially resolved observations (5'') of 151 wavelengths between 5.1 and 16.5 microns with a spectral resolution R = 35 to 50. We observe atomic emission lines ([Ne II], [Ne III], and [S IV]), several "unidentified infrared bands" (UIBs; 6.2, 7.7, 8.6, 11.3, 12.0, and 12.7 microns), and in some cases a continuum which rises steeply at longer wavelengths. We conclude that the spectra of these three GHRs are well explained by combinations of ionized gas, PAHs, and very small grains in various proportions and with different spatial distributions. Comparisons between observed ratios of the various UIBs with model ratios indicate that the PAHs in all three of the GHRs are dehydrogenated and that the small PAHs have been destroyed in IC 133 but have survived in NGC 595 and CC 93. The [Ne III]/[Ne II] ratios observed in IC 133 and NGC 595 are consistent with their ages of 5 and 4.5 Myr, respectively; the deduced ionization parameter is higher in IC 133, consistent with its more compact region of emission.

  4. ISO Mid-Infrared Observations of Giant HII Regions in M33

    Science.gov (United States)

    Skelton, B. P.; Waller, W. H.; Hodge, P. W.; Boulanger, F.; Cornett, R. H.; Fanelli, M. N.; Lequeux, J.; Stecher, T. P.; Viallefond, F.; Hui, Y.

    1999-01-01

    We present Infrared Space Observatory Camera (ISOCAM) Circular Variable Filter scans of three giant HII regions in M33. IC 133, NGC 595, and CC 93 span a wide range of metallicity, luminosity, nebular excitation, and infrared excess; three other emission regions (CC 43, CC 99, and a region to the northeast of the core of NGC 595) are luminous enough in the mid-infrared to be detected in the observed fields. ISOCAM CVF observations provide spatially resolved observations (5'') of 151 wavelengths between 5.1 and 16.5 microns with a spectral resolution R = 35 to 50. We observe atomic emission lines ([Ne II], [Ne III], and [S IV]), several "unidentified infrared bands" (UIBs; 6.2, 7.7, 8.6, 11.3, 12.0, and 12.7 microns), and in some cases a continuum which rises steeply at longer wavelengths. We conclude that the spectra of these three GHRs are well explained by combinations of ionized gas, PAHs, and very small grains in various proportions and with different spatial distributions. Comparisons between observed ratios of the various UIBs with model ratios indicate that the PAHs in all three of the GHRs are dehydrogenated and that the small PAHs have been destroyed in IC 133 but have survived in NGC 595 and CC 93. The [Ne III]/[Ne II] ratios observed in IC 133 and NGC 595 are consistent with their ages of 5 and 4.5 Myr, respectively; the deduced ionization parameter is higher in IC 133, consistent with its more compact region of emission.

  5. The UK Infrared Telescope M33 monitoring project. V. The star formation history across the galactic disc

    CERN Document Server

    Javadi, Atefeh; Khosroshahi, Habib; Tabatabaei, Fatemeh; Golshan, Roya Hamedani; Rashidi, Maryam

    2016-01-01

    We have conducted a near-infrared monitoring campaign at the UK InfraRed Telescope (UKIRT), of the Local Group spiral galaxy M33 (Triangulum). On the basis of their variability, we have identified stars in the very final stage of their evolution, and for which the luminosity is more directly related to the birth mass than the more numerous less-evolved giant stars that continue to increase in luminosity. In this fifth paper of the series, we construct the birth mass function and hence derive the star formation history across the galactic disc of M33. The star formation rate has varied between $\\sim0.010\\pm0.001$ ($\\sim0.012\\pm0.007$) and 0.060$\\pm0.005$ (0.052$\\pm0.009$)M$_\\odot$ yr$^{-1}$ kpc$^{-2}$ statistically (systematically) in the central square kiloparsec of M33, comparable with the values derived previously with another camera. The total star formation rate in M33 within a galactocentric radius of 14 kpc has varied between $\\sim0.110\\pm0.005$ ($\\sim0.174\\pm0.060$) and $\\sim0.560\\pm0.028$ ($\\sim0.503\\...

  6. In Search of a Radio Counterpart for the Ultraluminous X-Ray Source at the Nucleus of M33

    Directory of Open Access Journals (Sweden)

    A. Trejo

    2004-01-01

    Full Text Available Presentamos un análisis de observaciones de radiocontinuo del núcleo de la galaxia espiral M33, obtenidas del archivo del Very Large Array. La mayoría de estas observaciones fueron hechas con alta resolución angular (<1`` en varias épocas y las hemos utilizado para buscar emisión de radio asociada con la fuente ultraluminosa de rayos X en el centro de M33. A 20 cm, con una resolución angular de 1.3, detectamos una fuente con densidad de flujo de 0:200:02 mJy que coincide dentro de 0.2 con la posición del centro de M33 reportada por 2MASS. Adicionalmente, a 3.6 cm (con una resolución angular de 0.3, detectamos dos fuentes débiles, una de ellas con densidad de ujo de 0:04 0:01 mJy y que coincide con la fuente a 20 cm (y por lo tanto con el centro de M33. La segunda fuente detectada a 3.6 cm, con densidad de flujo de 0:05 0:01 mJy, está 0.6 al norte de la primera fuente. La posición para la fuente ultraluminosa de rayos X del satélite Chandra traslapa dentro del error con ambas fuentes de 3.6 cm.

  7. Four New Isovalertatins M33, D13, D33, and D43, from the Culture Filtrate of Streptomyces luteogriseus

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Four new aminooligosaccharides, isovalertatins M33 1, D13 2, D33 3, and D43 4, were isolated from the culture filtrate of Streptomyces luteogriseus. Their structures were established by chemical and spectroscopic evidences including ESI multistage mass spectrometry and 2-dimensional NMR techniques, and were found in full consistencies with the previous profiling results proposed by LC/ESI/MS analysis.

  8. A 15.65-solar-mass black hole in an eclipsing binary in the nearby spiral galaxy M 33.

    Science.gov (United States)

    Orosz, Jerome A; McClintock, Jeffrey E; Narayan, Ramesh; Bailyn, Charles D; Hartman, Joel D; Macri, Lucas; Liu, Jiefeng; Pietsch, Wolfgang; Remillard, Ronald A; Shporer, Avi; Mazeh, Tsevi

    2007-10-18

    Stellar-mass black holes are found in X-ray-emitting binary systems, where their mass can be determined from the dynamics of their companion stars. Models of stellar evolution have difficulty producing black holes in close binaries with masses more than ten times that of the Sun (>10; ref. 4), which is consistent with the fact that the most massive stellar black holes known so far all have masses within one standard deviation of 10. Here we report a mass of (15.65 +/- 1.45) for the black hole in the recently discovered system M 33 X-7, which is located in the nearby galaxy Messier 33 (M 33) and is the only known black hole that is in an eclipsing binary. To produce such a massive black hole, the progenitor star must have retained much of its outer envelope until after helium fusion in the core was completed. On the other hand, in order for the black hole to be in its present 3.45-day orbit about its (70.0 +/- 6.9) companion, there must have been a 'common envelope' phase of evolution in which a significant amount of mass was lost from the system. We find that the common envelope phase could not have occurred in M 33 X-7 unless the amount of mass lost from the progenitor during its evolution was an order of magnitude less than what is usually assumed in evolutionary models of massive stars.

  9. The Supernova Progenitor Mass Distributions of M31 and M33: Further Evidence for an Upper Mass Limit

    CERN Document Server

    Jennings, Zachary G; Murphy, Jeremiah W; Dalcanton, Julianne J; Gilbert, Karoline M; Dolphin, Andrew E; Weisz, Daniel R; Fouesneau, Morgan

    2014-01-01

    Using Hubble Space Telescope (HST) photometry to measure star formation histories, we age-date the stellar populations surrounding supernova remnants (SNRs) in M31 and M33. We then apply stellar evolution models to the ages to infer the corresponding masses for their supernova progenitor stars. We analyze 33 M33 SNR progenitors and 29 M31 SNR progenitors in this work. We then combine these measurements with 53 previously published M31 SNR progenitor measurements to bring our total number of progenitor mass estimates to 115. To quantify the mass distributions, we fit power laws of the form $dN/dM \\propto M^{-\\alpha}$. Our new, larger sample of M31 progenitors follows a distribution with $\\alpha = 4.4\\pm 0.4$, and the M33 sample follows a distribution with $\\alpha = 3.8^{+0.4}_{-0.5}$. Thus both samples are consistent within the uncertainties, and the full sample across both galaxies gives $\\alpha = 4.2\\pm 0.3$. Both the individual and full distributions display a paucity of massive stars when compared to a Sal...

  10. How cosmic-ray electron propagation affects radio-far-infrared correlations in M31 and M33

    CERN Document Server

    Berkhuijsen, Elly M; Tabatabaei, Fatemeh S

    2013-01-01

    We investigate the effect of propagation of cosmic-ray electrons (CRE) on the nonthermal (synchrotron) - far-infrared correlations in M31 and M33. The thermal (TH) and nonthermal (NTH) emission components of the radio continuum emission at 1.4 GHz and one higher frequency are compared with dust emission from M31 and M33 using Spitzer data. In both galaxies the TH emission is linearly correlated with the emission from warm dust (24 \\mu m, 70 \\mu m), but the power laws of the NTH-FIR correlations have exponents b < 1 that increase with increasing frequency. Furthermore, the values of b for M33 are significantly smaller (b ~ 0.4) than those for M31 (b ~ 0.6). We interpret the differences in b as differences in the diffusion length of the CRE. We estimate the diffusion length in two ways: (1) by smoothing the NTH emission at the higher frequency until the correlation with NTH emission at 1.4 GHz has b = 1, and (2) by smoothing the TH emission until the correlation with the NTH emission at the same frequency ha...

  11. A Comparative Study of Giant Molecular Clouds in M51, M33 and the Large Magellanic Cloud

    CERN Document Server

    Hughes, Annie; Colombo, Dario; Schinnerer, Eva; Pety, Jerome; Leroy, Adam K; Dobbs, Clare L; Garcia-Burillo, Santiago; Thompson, Todd A; Dumas, Gaelle; Schuster, Karl F; Kramer, Carsten

    2013-01-01

    We compare the properties of giant molecular clouds (GMCs) in M51 identified by the Plateau de Bure Interferometer Whirlpool Arcsecond Survey (PAWS) with GMCs identified in wide-field, high resolution surveys of CO emission in M33 and the Large Magellanic Cloud (LMC). We find that GMCs in M51 are larger, brighter and have higher velocity dispersions relative to their size than equivalent structures in M33 and the LMC. These differences imply that there are genuine variations in the average mass surface density of the different GMC populations. To explain this, we propose that the pressure in the interstellar medium surrounding the GMCs plays a role in regulating their density and velocity dispersion. We find no evidence for a correlation between size and linewidth in any of M51, M33 or the LMC when the CO emission is decomposed into GMCs, although moderately robust correlations are apparent when regions of contiguous CO emission (with no size limitation) are used. Our work demonstrates that observational bias...

  12. Crystal chemical formula for sartorite homologues

    DEFF Research Database (Denmark)

    Makovicky, Emil; Topa, Dan

    2015-01-01

    The members of the sartorite homologous series are complex sulfides Me 2+ 8N–16–2X Me 3+ 16+X Me + XS8N+8where Me 2+ is Pb and Me 3+ is As and Sb, whereas Me + is Ag and/or Tl. This paper presents calculation formulae for the homologue order N and for the separate substitution percentages for Tl ...... + (As,Sb) ↔ 2Pb and Ag + (As,Sb) ↔ 2Pb substitutions. This enables one to evaluate the crystal chemistry and build a systematic classification of the sartorite homologues...

  13. The UK Infrared Telescope M 33 monitoring project - V. The star formation history across the galactic disc

    Science.gov (United States)

    Javadi, Atefeh; van Loon, Jacco Th.; Khosroshahi, Habib G.; Tabatabaei, Fatemeh; Hamedani Golshan, Roya; Rashidi, Maryam

    2017-01-01

    We have conducted a near-infrared monitoring campaign at the UK Infrared Telescope of the Local Group spiral galaxy M 33 (Triangulum). On the basis of their variability, we have identified stars in the very final stage of their evolution, and for which the luminosity is more directly related to the birth mass than the more numerous less-evolved giant stars that continue to increase in luminosity. In this fifth paper of the series, we construct the birth mass function and hence derive the star formation history across the galactic disc of M 33. The star formation rate has varied between ˜0.010 ± 0.001 (˜0.012 ± 0.007) and 0.060±0.005 (0.052±0.009) M⊙ yr-1 kpc-2 statistically (systematically) in the central square kiloparsec of M 33, comparable with the values derived previously with another camera. The total star formation rate in M 33 within a galactocentric radius of 14 kpc has varied between ˜0.110 ± 0.005 (˜0.174 ± 0.060) and ˜0.560 ± 0.028 (˜0.503 ± 0.100) M⊙ yr-1 statistically (systematically). We find evidence of two epochs during which the star formation rate was enhanced by a factor of a few - one that started ˜6 Gyr ago and lasted ˜3 Gyr and produced ≥71 per cent of the total mass in stars, and one ˜250 Myr ago that lasted ˜200 Myr and formed ≤13 per cent of the mass in stars. Radial star formation history profiles suggest that the inner disc of M 33 was formed in an inside-out formation scenario. The outskirts of the disc are dominated by the old population, which may be the result of dynamical effects over many Gyr. We find correspondence to spiral structure for all stars, but enhanced only for stars younger than ˜100 Myr; this suggests that the spiral arms are transient features and not a part of a global density wave potential.

  14. The supernova progenitor mass distributions of M31 and M33: further evidence for an upper mass limit

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, Zachary G.; Weisz, Daniel R. [University of California Observatories, Santa Cruz, CA 95064 (United States); Williams, Benjamin F.; Dalcanton, Julianne J.; Gilbert, Karoline M.; Fouesneau, Morgan [Box 351580, The University of Washington Seattle, WA 98195 (United States); Murphy, Jeremiah W. [Department of Physics, Florida State University, Tallahassee, FL 32306 (United States); Dolphin, Andrew E., E-mail: zgjennin@ucsc.edu, E-mail: adolphin@raytheon.com [Raytheon, 1151 E. Hermans Road, Tucson, AZ 85706 (United States)

    2014-11-10

    Using Hubble Space Telescope photometry to measure star formation histories, we age-date the stellar populations surrounding supernova remnants (SNRs) in M31 and M33. We then apply stellar evolution models to the ages to infer the corresponding masses for their supernova progenitor stars. We analyze 33 M33 SNR progenitors and 29 M31 SNR progenitors in this work. We then combine these measurements with 53 previously published M31 SNR progenitor measurements to bring our total number of progenitor mass estimates to 115. To quantify the mass distributions, we fit power laws of the form dN/dM∝M {sup –α}. Our new larger sample of M31 progenitors follows a distribution with α=4.4{sub −0.4}{sup +0.4}, and the M33 sample follows a distribution with α=3.8{sub −0.5}{sup +0.4}. Thus both samples are consistent within the uncertainties, and the full sample across both galaxies gives α=4.2{sub −0.3}{sup +0.3}. Both the individual and full distributions display a paucity of massive stars when compared to a Salpeter initial mass function, which we would expect to observe if all massive stars exploded as SN that leave behind observable SNR. If we instead fix α = 2.35 and treat the maximum mass as a free parameter, we find M {sub max} ∼ 35-45 M {sub ☉}, indicative of a potential maximum cutoff mass for SN production. Our results suggest that either SNR surveys are biased against finding objects in the youngest (<10 Myr old) regions, or the highest mass stars do not produce SNe.

  15. Observations of M31 and M33 with the Fermi Large Area Telescope: A Galactic Center Excess in Andromeda?

    Science.gov (United States)

    Ackermann, M.; Ajello, M.; Albert, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Cameron, R. A.; Caputo, R.; Caragiulo, M.; Caraveo, P. A.; Cavazzuti, E.; Cecchi, C.; Charles, E.; Chekhtman, A.; Chiaro, G.; Ciprini, S.; Costanza, F.; Cutini, S.; D’Ammando, F.; de Palma, F.; Desiante, R.; Digel, S. W.; Di Lalla, N.; Di Mauro, M.; Di Venere, L.; Favuzzi, C.; Funk, S.; Fusco, P.; Gargano, F.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Green, D.; Grenier, I. A.; Guillemot, L.; Guiriec, S.; Hayashi, K.; Hou, X.; Jóhannesson, G.; Kamae, T.; Knödlseder, J.; Kong, A. K. H.; Kuss, M.; La Mura, G.; Larsson, S.; Latronico, L.; Li, J.; Longo, F.; Loparco, F.; Lubrano, P.; Maldera, S.; Malyshev, D.; Manfreda, A.; Martin, P.; Mazziotta, M. N.; Michelson, P. F.; Mirabal, N.; Mitthumsiri, W.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Negro, M.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orlando, E.; Ormes, J. F.; Paneque, D.; Persic, M.; Pesce-Rollins, M.; Piron, F.; Porter, T. A.; Principe, G.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, O.; Sánchez-Conde, M.; Sgrò, C.; Simone, D.; Siskind, E. J.; Spada, F.; Spandre, G.; Spinelli, P.; Tanaka, K.; Tibaldo, L.; Torres, D. F.; Troja, E.; Uchiyama, Y.; Wang, J. C.; Wood, K. S.; Wood, M.; Zaharijas, G.; Zhou, M.

    2017-02-01

    The Fermi Large Area Telescope (LAT) has opened the way for comparative studies of cosmic rays (CRs) and high-energy objects in the Milky Way (MW) and in other, external, star-forming galaxies. Using 2 yr of observations with the Fermi LAT, Local Group galaxy M31 was detected as a marginally extended gamma-ray source, while only an upper limit has been derived for the other nearby galaxy M33. We revisited the gamma-ray emission in the direction of M31 and M33 using more than 7 yr of LAT Pass 8 data in the energy range 0.1{--}100 {GeV}, presenting detailed morphological and spectral analyses. M33 remains undetected, and we computed an upper limit of 2.0× {10}-12 {erg} {{cm}}-2 {{{s}}}-1 on the 0.1{--}100 {GeV} energy flux (95% confidence level). This revised upper limit remains consistent with the observed correlation between gamma-ray luminosity and star formation rate tracers and implies an average CR density in M33 that is at most half of that of the MW. M31 is detected with a significance of nearly 10σ . Its spectrum is consistent with a power law with photon index {{Γ }}=2.4+/- {0.1}{stat+{syst}} and a 0.1{--}100 {GeV} energy flux of (5.6+/- {0.6}{stat+{syst}})× {10}-12 {erg} {{cm}}-2 {{{s}}}-1. M31 is detected to be extended with a 4σ significance. The spatial distribution of the emission is consistent with a uniform-brightness disk with a radius of 0.°4 and no offset from the center of the galaxy, but nonuniform intensity distributions cannot be excluded. The flux from M31 appears confined to the inner regions of the galaxy and does not fill the disk of the galaxy or extend far from it. The gamma-ray signal is not correlated with regions rich in gas or star formation activity, which suggests that the emission is not interstellar in origin, unless the energetic particles radiating in gamma rays do not originate in recent star formation. Alternative and nonexclusive interpretations are that the emission results from a population of millisecond pulsars

  16. Infrared Survey of Pulsating Giant Stars in the Spiral Galaxy M33: Dust Production, Star Formation History, and Galactic Structure

    CERN Document Server

    Javadi, Atefeh; Mirtorabi, Mohammad Taghi

    2011-01-01

    We introduce a near-IR monitoring campaign of the Local Group spiral galaxy M33, carried out with the UK IR Telescope (UKIRT). The pulsating giant stars are identified and their distributions are used to derive the star formation rate as a function of age. We here present the star formation history for the central square kiloparsec. These stars are also important dust factories; we measure their dust production rates from a combination of our data with Spitzer Space Telescope mid-IR photometry.

  17. Suzaku investigation into the nature of the nearest ultraluminous X-ray source, M33 X-8

    CERN Document Server

    Isobe, Naoki; Sato, Hiroshi; Mizuno, Tsunefumi

    2012-01-01

    The X-ray spectrum of the nearest ultraluminous X-ray source, M33 X-8, obtained by Suzaku during 2010 January 11 -- 13, was closely analyzed to examine its nature. It is, by far, the only data with the highest signal statistic in 0.4 -- 10 keV range. Despite being able to reproduce the X-ray spectrum, Comptonization of the disk photons failed to give a physically meaningful solution. A modified version of the multi-color disk model, in which the dependence of the disk temperature on the radius is described as r^(-p) with p being a free parameter, can also approximate the spectrum. From this model, the innermost disk temperature and bolometric luminosity were obtained as T_in = 2.00-0.05+0.06 keV and L_disk = 1.36 x 10^39 (cos i)^(-1) ergs/s, respectively, where i is the disk inclination. A small temperature gradient of p = 0.535-0.005+0.004, together with the high disk temperature, is regarded as the signatures of the slim accretion disk model, suggesting that M33 X-8 was accreting at high mass accretion rate...

  18. The Identification of Extreme Asymptotic Giant Branch Stars and Red Supergiants in M33 by 24 {\\mu}m Variability

    CERN Document Server

    Montiel, Edward J; Clayton, Geoffrey C; Engelbracht, Charles W; Johnson, Christopher B

    2014-01-01

    We present the first detection of 24 {\\mu}m variability in 24 sources in the Local Group galaxy M33. These results are based on 4 epochs of MIPS observations, which are irregularly spaced over ~750 days. We find that these sources are constrained exclusively to the Holmberg radius of the galaxy, which increases their chances of being members of M33. We have constructed spectral energy distributions (SEDs) ranging from the optical to the sub-mm to investigate the nature of these objects. We find that 23 of our objects are most likely heavily self-obscured, evolved stars; while the remaining source is the Giant HII region, NGC 604. We believe that the observed variability is the intrinsic variability of the central star reprocessed through their circumstellar dust shells. Radiative transfer modeling was carried out to determine their likely chemical composition, luminosity, and dust production rate (DPR). As a sample, our modeling has determined an average luminosity of (3.8 $\\pm$ 0.9) x 10$^4$ L$_\\odot$ and a ...

  19. Constraints on the Compact Object Mass in the Eclipsing HMXB XMMU J013236.7+303228 in M33

    CERN Document Server

    Bhalerao, Varun; Harrison, Fiona

    2012-01-01

    We present optical spectroscopic measurements of the eclipsing High Mass X-ray Binary XMMU J013236.7+303228 in M33. Based on spectra taken at multiple epochs of the 1.73d binary orbital period we determine physical as well as orbital parameters for the donor star. We find the donor to be a B1.5IV sub-giant with effective temperature T=22,000-23,000 K. From the luminosity, temperature and known distance to M33 we derive a radius of R = 8.9 \\pm 0.5 R_sun. From the radial--velocity measurements, we determine a velocity semi-amplitude of K_opt = 63 \\pm 12 km/sec. Using the physical properties of the B-star determined from the optical spectrum, we estimate the star's mass to be M_opt = 11 \\pm 1 M_sun. Based on the X-ray spectrum, the compact companion is likely a neutron star, although no pulsations have yet been detected. Using the spectroscopically derived B-star mass we find the neutron star companion mass to be M_X = 2.0 \\pm 0.4 M_sun, consistent with the neutron star mass in the HMXB Vela X-1, but heavier tha...

  20. The Heating of Mid-Infrared Dust in the Nearby Galaxy M33: A Testbed for Tracing Galaxy Evolution

    CERN Document Server

    Calapa, M; Draine, B T; Boquien, M; Kramer, C; Xilouris, M; Verley, S; Braine, J; Relaño-Pastor, M; van der Werf, P; Israel, F; Hermelo, I; Albrecht, M

    2014-01-01

    Because the 8 {\\mu}m polycyclic aromatic hydrocarbon (PAH) emission has been found to correlate with other well-known star formation tracers, it has widely been used as a star formation rate (SFR) tracer. There are, however, studies that challenge the accuracy and reliability of the 8 {\\mu}m emission as a SFR tracer. Our study, part of the Herschel M33 Extended Survey (HERM33ES) open time key program, aims at addressing this issue by analyzing the infrared emission from the nearby spiral galaxy M33 at the high spatial scale of 75 pc. Combining data from the Herschel Space Observatory and the Spitzer Space Telescope we find that the 8 {\\mu}m emission is better correlated with the 250 {\\mu}m emission, which traces cold interstellar gas, than with the 24 {\\mu}m emission. The L(8)/L(24) ratio is highly depressed in 24 {\\mu}m luminous regions, which correlate with known HII regions. We also compare our results with the dust emission models by Draine & Li (2007). We confirm that the depression of 8 {\\mu}m PAH e...

  1. Growth, photosynthetic efficiency, and biochemical composition of Tetraselmis suecica F&M-M33 grown with LEDs of different colors.

    Science.gov (United States)

    Abiusi, Fabian; Sampietro, Giacomo; Marturano, Giovanni; Biondi, Natascia; Rodolfi, Liliana; D'Ottavio, Massimo; Tredici, Mario R

    2014-05-01

    The effect of light quality on cell size and cell cycle, growth rate, productivity, photosynthetic efficiency and biomass composition of the marine prasinophyte Tetraselmis suecica F&M-M33 grown in 2-L flat panel photobioreactors illuminated with light emitting diodes (LEDs) of different colors was investigated. Biomass productivity and photosynthetic efficiency were comparable between white and red light, while under blue and green light productivity decreased to less than half and photosynthetic efficiency to about one third. Differences in cell size and number correlated with the cell cycle phase. Under red light cells were smaller and more motile. Chlorophyll content was strongly reduced with red and enhanced with blue light, while carotenoids and gross biomass composition were not affected by light quality. The eicosapentaenoic acid content increased under red light. Red light can substitute white light without affecting productivity of T. suecica F&M-M33, leading to smaller and more motile cells and increased eicosapentaenoic acid content. Red LEDs can thus be profitably used for the production of this microalga for aquaculture.

  2. A Deep XMM-Newton Survey of M33: Point Source Catalog, Source Detection and Characterization of Overlapping Fields

    CERN Document Server

    Williams, Benjamin F; Haberl, Frank; Garofali, Kristen; Blair, William P; Gaetz, Terrance J; Kuntz, K D; Long, Knox S; Pannuti, Thomas G; Pietsch, Wolfgang; Plucinsky, Paul P; Winkler, P Frank

    2015-01-01

    We have obtained a deep 8-field XMM-Newton mosaic of M33 covering the galaxy out to the D$_{25}$ isophote and beyond to a limiting 0.2--4.5 keV unabsorbed flux of 5$\\times$10$^{-16}$ erg cm$^{-2}$ s$^{-1}$ (L${>}$4$\\times$10$^{34}$ erg s$^{-1}$ at the distance of M33). These data allow complete coverage of the galaxy with high sensitivity to soft sources such as diffuse hot gas and supernova remnants. Here we describe the methods we used to identify and characterize 1296 point sources in the 8 fields. We compare our resulting source catalog to the literature, note variable sources, construct hardness ratios, classify soft sources, analyze the source density profile, and measure the X-ray luminosity function. As a result of the large effective area of XMM-Newton below 1 keV, the survey contains many new soft X-ray sources. The radial source density profile and X-ray luminosity function for the sources suggests that only $\\sim$15% of the 391 bright sources with L${>}$3.6$\\times$10$^{35}$ erg s$^{-1}$ are likely...

  3. VizieR Online Data Catalog: The M33 Synoptic Stellar Survey. II. Mira variables (Yuan+, 2017)

    Science.gov (United States)

    Yuan, W.; He, S.; Macri, L. M.; Long, J.; Huang, J. Z.

    2017-08-01

    We carried out a search for Mira variables in M33 using sparsely sampled I-band light curves. We based our search on the observations of M33 obtained by Macri et al. 2001 (Cat. J/AJ/121/861) and Pellerin et al. 2011 (Cat. J/ApJS/193/26). These surveys covered most of the disk of this galaxy with a combined baseline of nearly a decade (1996 September to 1999 November for Macri et al. 2001, Cat. J/AJ/121/861; 2002 August to 2006 August for Pellerin et al. 2011, Cat. J/ApJS/193/26) mainly using the Fred L. Whipple Observatory (FLWO) 1.2m and the WIYN observatory 3.5m telescopes with a variety of cameras (see the respective publications for details). While images were obtained in multiple bandpasses (BVI), our analysis is only based on the I-band time-series photometry because Mira candidates fall below the detection limit in the bluer bands. Our final sample consists of 1847 Mira candidates (see Table2). (1 data file).

  4. The UK Infrared Telescope M33 monitoring project. IV. Variable red giant stars across the galactic disc

    CERN Document Server

    Javadi, Atefeh; van Loon, Jacco Th; Khosroshahi, Habib; Golabatooni, Najmeh; Mirtorabi, Mohammad Taghi

    2014-01-01

    We have conducted a near-infrared monitoring campaign at the UK InfraRed Telescope (UKIRT), of the Local Group spiral galaxy M33 (Triangulum). The main aim was to identify stars in the very final stage of their evolution, and for which the luminosity is more directly related to the birth mass than the more numerous less-evolved giant stars that continue to increase in luminosity. In this fourth paper of the series, we present a search for variable red giant stars in an almost square degree region comprising most of the galaxy's disc, carried out with the WFCAM instrument in the K band. These data, taken during the period 2005--2007, were complemented by J- and H-band images. Photometry was obtained for 403 734 stars in this region; of these, 4643 stars were found to be variable, most of which are Asymptotic Giant Branch (AGB) stars. The variable stars are concentrated towards the centre of M33, more so than low-mass, less-evolved red giants. Our data were matched to optical catalogues of variable stars and ca...

  5. PAndAS IN THE MIST: THE STELLAR AND GASEOUS MASS WITHIN THE HALOS OF M31 AND M33

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Geraint F. [Sydney Institute for Astronomy, School of Physics A28, The University of Sydney, NSW 2006 (Australia); Braun, Robert [CSIRO Astronomy and Space Science, P.O. Box 76, Epping, NSW 1710 (Australia); McConnachie, Alan W. [Dominion Astrophysical Observatory, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Irwin, Michael J.; Chapman, Scott C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Ibata, Rodrigo A.; Martin, Nicolas F. [Observatoire de Strasbourg, 11, rue de l' Universite, F-67000 Strasbourg (France); Ferguson, Annette M. N. [Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Fardal, Mark [Department of Astronomy, University of Massachusetts, Amherst, MA 01003-9305 (United States); Dubinski, John [Department of Astronomy and Astrophysics, 50 St. George Street, University of Toronto, ON M5S 3H4 (Canada); Widrow, Larry [Department of Physics, Queen' s University, 99 University Avenue, Kingston, ON K7L 3N6 (Canada); Mackey, A. Dougal [Research School of Astronomy and Astrophysics, Mount Stromlo Observatory, Cotter Road, Weston Creek, ACT 2611 (Australia); Babul, Arif [Department of Physics and Astronomy, University of Victoria, Victoria, BC V8W 3P6 (Canada); Tanvir, Nial R. [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); Rich, Michael, E-mail: geraint.lewis@sydney.edu.au [Division of Astronomy, University of California, 8979 Math Sciences, Los Angeles, CA 90095-1562 (United States)

    2013-01-20

    Large-scale surveys of the prominent members of the Local Group have provided compelling evidence for the hierarchical formation of massive galaxies, revealing a wealth of substructure that is thought to be the debris from ancient and ongoing accretion events. In this paper, we compare two extant surveys of the M31-M33 subgroup of galaxies: the Pan-Andromeda Archaeological Survey of the stellar structure, and a combination of observations of the H I gaseous content, detected at 21 cm. Our key finding is a marked lack of spatial correlation between these two components on all scales, with only a few potential overlaps between stars and gas. The paucity of spatial correlation significantly restricts the analysis of kinematic correlations, although there does appear to be H I kinematically associated with the Giant Stellar Stream where it passes the disk of M31. These results demonstrate that different processes must significantly influence the dynamical evolution of the stellar and H I components of substructures, such as ram pressure driving gas away from a purely gravitational path. Detailed modeling of the offset between the stellar and gaseous substructures will provide a determination of the properties of the gaseous halos of M31 and M33.

  6. Orbits of massive satellite galaxies - I. A close look at the Large Magellanic Cloud and a new orbital history for M33

    Science.gov (United States)

    Patel, Ekta; Besla, Gurtina; Sohn, Sangmo Tony

    2017-02-01

    The Milky Way (MW) and M31 both harbour massive satellite galaxies, the Large Magellanic Cloud (LMC) and M33, which may comprise up to 10 per cent of their host's total mass. Massive satellites can change the orbital barycentre of the host-satellite system by tens of kiloparsec and are cosmologically expected to harbour dwarf satellite galaxies of their own. Assessing the impact of these effects crucially depends on the orbital histories of the LMC and M33. Here, we revisit the dynamics of the MW-LMC system and present the first detailed analysis of the M31-M33 system utilizing high-precision proper motions and statistics from the dark-matter-only Illustris cosmological simulation. With the latest Hubble Space Telescope proper motion measurements of M31, we reliably constrain M33's interaction history with its host. In particular, like the LMC, M33 is either on its first passage (tinf picture and provide further insight about their host masses. We conclude that, cosmologically, massive satellites such as the LMC and M33 are likely completing their first orbits about their hosts. We also find that the orbital energies of such analogues prefer an MW halo mass ˜1.5 × 1012 M⊙ and an M31 halo mass ≥1.5 × 1012 M⊙. Despite conventional wisdom, we conclude it is highly improbable that M33 made a close (<100 kpc) approach to M31 recently (tperi < 3 Gyr ago). Such orbits are rare (<1 per cent) within the 4σ error space allowed by observations. This conclusion cannot be explained by perturbative effects through four-body encounters amongst the MW, M31, M33, and the LMC. This surprising result implies that we must search for a new explanation for M33's strongly warped gas and stellar discs.

  7. Formation of the black-hole binary M33 X-7 through mass exchange in a tight massive system.

    Science.gov (United States)

    Valsecchi, Francesca; Glebbeek, Evert; Farr, Will M; Fragos, Tassos; Willems, Bart; Orosz, Jerome A; Liu, Jifeng; Kalogera, Vassiliki

    2010-11-04

    The X-ray source M33 X-7 in the nearby galaxy Messier 33 is among the most massive X-ray binary stellar systems known, hosting a rapidly spinning, 15.65M(⊙) black hole orbiting an underluminous, 70M(⊙) main-sequence companion in a slightly eccentric 3.45-day orbit (M(⊙), solar mass). Although post-main-sequence mass transfer explains the masses and tight orbit, it leaves unexplained the observed X-ray luminosity, the star's underluminosity, the black hole's spin and the orbital eccentricity. A common envelope phase, or rotational mixing, could explain the orbit, but the former would lead to a merger and the latter to an overluminous companion. A merger would also ensue if mass transfer to the black hole were invoked for its spin-up. Here we report simulations of evolutionary tracks which reveal that if M33 X-7 started as a primary body of 85M(⊙)-99M(⊙) and a secondary body of 28M(⊙)-32M(⊙), in a 2.8-3.1-d orbit, its observed properties can be consistently explained. In this model, the main-sequence primary transfers part of its envelope to the secondary and loses the rest in a wind; it ends its life as a ∼16M(⊙) helium star with an iron-nickel core that collapses to a black hole (with or without an accompanying supernova). The release of binding energy, and possibly collapse asymmetries, 'kick' the nascent black hole into an eccentric orbit. Wind accretion explains the X-ray luminosity, and the black-hole spin can be natal.

  8. Orbits of Massive Satellite Galaxies: I. A Close Look at the Large Magellanic Cloud and a New Orbital History for M33

    CERN Document Server

    Patel, Ekta; Sohn, Tony

    2016-01-01

    The Milky Way (MW) and M31 both harbor massive satellite galaxies, the Large Magellanic Cloud (LMC) and M33, which may comprise up to 10 per cent of their host's total mass. Massive satellites can change the orbital barycentre of the host-satellite system by tens of kiloparsecs and are cosmologically expected to harbor dwarf satellite galaxies of their own. Assessing the impact of these effects depends crucially on the orbital histories of the LMC and M33. Here, we revisit the dynamics of the MW-LMC system and present the first detailed analysis of the M31-M33 system utilizing high precision proper motions and statistics from the dark matter-only Illustris cosmological simulation. With the latest Hubble Space Telescope proper motion measurements of M31, we reliably constrain M33's interaction history with its host. In particular, like the LMC, M33 is either on its first passage (t_{inf} =2x10^12 Msun), it is on a long period orbit of about 6 Gyr. Cosmological analogs of the LMC and M33 identified in Illustris...

  9. PAndAS in the mist: The stellar and gaseous mass within the halos of M31 and M33

    CERN Document Server

    Lewis, Geraint F; McConnachie, Alan W; Irwin, Michael J; Ibata, Rodrigo A; Chapman, Scott C; Ferguson, Annette M N; Martin, Nicolas F; Fardal, Mark; Dubinski, John; Widrow, Larry; Mackey, A Dougal; Babul, Arif; Tanvir, Nial; Rich, Michael

    2012-01-01

    Large scale surveys of the prominent members of the Local Group have provided compelling evidence for the hierarchical formation of massive galaxies, revealing a wealth of substructure that is thought to be the debris from ancient and on-going accretion events. In this paper, we compare two extant surveys of the M31-M33 subgroup of galaxies; the Pan-Andromeda Archaeological Survey (PAndAS) of the stellar structure, and a combination of observations of the HI gaseous content, detected at 21cm. Our key finding is a marked lack of spatial correlation between these two components on all scales, with only a few potential overlaps between stars and gas.The paucity of spatial correlation significantly restricts the analysis of kinematic correlations, although there does appear to the HI kinematically associated with the Giant Stellar Stream where it passes the disk of M31. These results demonstrate that that different processes must significantly influence the dynamical evolution of the stellar and HI components of ...

  10. The IRAM M33 CO(2-1) Survey - A complete census of the molecular gas out to 7 kpc

    CERN Document Server

    Druard, C; Schuster, K F; Schneider, N; Gratier, P; Bontemps, S; Boquien, M; Combes, F; Corbelli, E; Henkel, C; Herpin, F; Kramer, C; van der Tak, F; van der Werf, P

    2014-01-01

    In order to study the ISM and the interplay between the atomic and molecular components in a low-metallicity environment, we present a complete high angular and spectral resolution map and data cube of the 12CO(2-1) emission from the Local Group galaxy M33. Its metallicity is roughly half-solar, such that we can compare its ISM with that of the Milky Way with the main changes being the metallicity and the gas mass fraction. The data have a 12" angular resolution (50pc) with a spectral resolution of 2.6 km/s and a mean noise level of 20 mK per channel in antenna temperature. A radial cut along the major axis was also observed in the 12CO(1-0) line. The CO data cube and integrated intensity map are optimal when using HI data to define the baseline window and the velocities over which the CO emission is integrated. Great care was taken when building these maps, testing different windowing and baseline options and investigating the effect of error beam pickup. The total CO(2-1) luminosity is 2.8e7 K km/s pc2, fol...

  11. The UK Infrared Telescope M33 monitoring project. II. The star formation history in the central square kiloparsec

    CERN Document Server

    Javadi, Atefeh; Mirtorabi, Mohammad Taghi

    2011-01-01

    We have conducted a near-infrared monitoring campaign at the UK InfraRed Telescope (UKIRT), of the Local Group spiral galaxy M33 (Triangulum). The main aim was to identify stars in the very final stage of their evolution, and for which the luminosity is more directly related to the birth mass than the more numerous less-evolved giant stars that continue to increase in luminosity. In this second paper of the series, we construct the birth mass function and hence derive the star formation history. The star formation rate has varied between ~0.002 and 0.007 M ̇ yr^-1 kpc^-2. We give evidence of two epochs of a star formation rate enhanced by a factor of a few -- one that happened \\geq 6 Gyr ago and produced \\geq 80% of the total mass in stars, and one around 250 Myr ago that lasted ~ 200 Myr and formed \\leq 6% of the mass in stars. We construct radial and azimuthal distributions in the image plane and in the galaxy plane for populations associated with old first-ascent red giant branch (RGB) stars, intermedia...

  12. The UK Infrared Telescope M33 monitoring project. I. Variable red giant stars in the central square kiloparsec

    CERN Document Server

    Javadi, Atefeh; Mirtorabi, Mohammad Taghi

    2010-01-01

    We have conducted a near-infrared monitoring campaign at the UK InfraRed Telescope (UKIRT), of the Local Group spiral galaxy M33 (Triangulum). The main aim was to identify stars in the very final stage of their evolution, and for which the luminosity is more directly related to the birth mass than the more numerous less-evolved giant stars that continue to increase in luminosity. The most extensive dataset was obtained in the K-band with the UIST instrument for the central 4'x 4' (1 square kpc) - this contains the nuclear star cluster and inner disc. These data, taken during the period 2003-2007, were complemented by J- and H-band images. Photometry was obtained for 18,398 stars in this region; of these, 812 stars were found to be variable, most of which are Asymptotic Giant Branch (AGB) stars. Our data were matched to optical catalogues of variable stars and carbon stars, and to mid-infrared photometry from the Spitzer Space Telescope. In this first of a series of papers, we present the methodology of the va...

  13. The UK Infrared Telescope M33 monitoring project. III. Feedback from dusty stellar winds in the central square kiloparsec

    CERN Document Server

    Javadi, Atefeh; Khosroshahi, Habib; Mirtorabi, Mohammad Taghi

    2013-01-01

    We have conducted a near-infrared monitoring campaign at the UK InfraRed Telescope (UKIRT), of the Local Group spiral galaxy M33 (Triangulum). The main aim was to identify stars in the very final stage of their evolution, and for which the luminosity is more directly related to the birth mass than the more numerous less-evolved giant stars that continue to increase in luminosity. In this third paper of the series, we measure the dust production and rates of mass loss by the pulsating Asymptotic Giant Branch (AGB) stars and red supergiants. To this aim, we combined our time-averaged near-IR photometry with the multi-epoch mid-IR photometry obtained with the Spitzer Space Telescope. The mass-loss rates are seen to increase with increasing strength of pulsation and with increasing bolometric luminosity. Low-mass stars lose most of their mass through stellar winds, but even super-AGB stars and red supergiants lose $\\sim40$% of their mass via a dusty stellar wind. More than three-quarters of the dust return is oxy...

  14. Is the Prosthetic Homologue Necessary for Embodiment?

    Science.gov (United States)

    Dornfeld, Chelsea; Swanston, Michelle; Cassella, Joseph; Beasley, Casey; Green, Jacob; Moshayev, Yonatan; Wininger, Michael

    2016-01-01

    Embodiment is the process by which patients with limb loss come to accept their peripheral device as a natural extension of self. However, there is little guidance as to how exacting the prosthesis must be in order for embodiment to take place: is it necessary for the prosthetic hand to look just like the absent hand? Here, we describe a protocol for testing whether an individual would select a hand that looks like their own from among a selection of five hands, and whether the hand selection (regardless of homology) is consistent across multiple exposures to the same (but reordered) set of candidate hands. Pilot results using healthy volunteers reveals that hand selection is only modestly consistent, and that selection of the prosthetic homologue is atypical (61 of 192 total exposures). Our protocol can be executed in minutes, and makes use of readily available equipment and softwares. We present both a face-to-face and a virtual protocol, for maximum flexibility of implementation. PMID:28066228

  15. Is the prosthetic homologue necessary for embodiment?

    Directory of Open Access Journals (Sweden)

    Chelsea Dornfeld

    2016-12-01

    Full Text Available Embodiment is the process by which patients with limb loss come to accept their peripheral device as a natural extension of self. However, there is little guidance as to how exacting the prosthesis must be in order for embodiment to take place: is it necessary for the prosthetic hand to look just like the absent hand? Here, we describe a protocol for testing whether an individual would select a hand that looks like their own from among a selection of 5 hands, and whether the hand selection (regardless of homology is consistent across multiple exposures to the same (but reordered set of candidate hands. Pilot results using healthy volunteers reveals that hand selection is only modestly consistent, and that selection of the prosthetic homologue is atypical (61 of 192 total exposures. Our protocol can be executed in minutes, and makes use of readily available equipment and softwares. We present both a face-to-face and a virtual protocol, for maximum flexibility of implementation.

  16. Evolved Massive Stars in the Local Group. I. Identification of Red Supergiants in NGC 6822, M31, and M33

    Science.gov (United States)

    Massey, Philip

    1998-07-01

    Knowledge of the red supergiant (RSG) population of nearby galaxies allows us to probe massive star evolution as a function of metallicity; however, contamination by foreground Galactic dwarfs dominates surveys for red stars in Local Group galaxies beyond the Magellanic Clouds. Model atmospheres predict that low-gravity supergiants will have B-V values that are redder by several tenths of a magnitude than foreground dwarfs at a given V-R color, a result that is largely independent of reddening. We conduct a BVR survey of several fields in the Local Group galaxies NGC 6822, M33, and M31 as well as neighboring control fields and identify RSG candidates from CCD photometry. The survey is complete to V = 20.5, corresponding to MV = -4.5 or an Mbol of -6.3 for the reddest stars. Follow-up spectroscopy at the Ca II triplet of 130 stars is used to demonstrate that our photometric criterion for identifying RSGs is highly successful (96% for stars brighter than V = 19.5; 82% for V = 19.5-20.5). Classification spectra are also obtained for a number of stars in order to calibrate color with spectral type empirically. We find that there is a marked progression in the average (B-V)0 and (V-R)0 colors of RSGs in these three galaxies, with the higher metallicity systems having a later average spectral type, which is consistent with previous findings by Elias, Frogel, & Humphreys for the Milky Way and Magellanic Clouds. More significantly, we find that there is a clear progression with metallicity in the relative number of the highest luminosity RSGs, a trend that is apparent both in absolute visual magnitude and in bolometric luminosity. Thus any use of RSGs as distance indicators requires correction for the metallicity of the parent galaxy. Our findings are in accord with the predictions of the ``Conti scenario'' in which higher metallicities result in higher mass-loss rates, resulting in a star of a given luminosity spending an increasing fraction of its He-burning lifetime as

  17. A Survey of the Local Group of Galaxies for Symbiotic Binary Stars. I. First detection of symbiotic stars in M33

    CERN Document Server

    Mikolajewska, Joanna; Caldwell, Nelson; Ilkiewicz, Krystian; Zurek, David

    2016-01-01

    We present and discuss initial selection criteria and first results in M33 from a systematic search for extragalactic symbiotic stars. We show that the presence of diffuse interstellar gas emission can significantly contaminate the spectra of symbiotic star candidates. This important effect forces upon us a more stringent working definition of an extragalactic symbiotic star. We report the first detections and spectroscopic characterisation of 12 symbiotic binaries in M33. We found that four of our systems contain carbon-rich giants. In another two of them the giant seems to be a Zr-enhanced MS star, while the remaining six objects host M-type giants. The high number ratio of C to M giants in these binaries is consistent with the low metallicity of M33. The spatial and radial velocity distributions of these new symbiotic binaries are consistent with a wide range of progenitor star ages.

  18. A survey of the Local Group of galaxies for symbiotic binary stars - I. First detection of symbiotic stars in M33

    Science.gov (United States)

    Mikołajewska, Joanna; Shara, Michael M.; Caldwell, Nelson; Iłkiewicz, Krystian; Zurek, David

    2017-02-01

    We present and discuss initial selection criteria and first results in M33 from a systematic search for extragalactic symbiotic stars. We show that the presence of diffuse ionized gas (DIG) emission can significantly contaminate the spectra of symbiotic star candidates. This important effect forces upon us a more stringent working definition of an extragalactic symbiotic star. We report the first detections and spectroscopic characterization of 12 symbiotic binaries in M33. We found that four of our systems contain carbon-rich giants. In another two of them, the giant seems to be a Zr-enhanced MS star, while the remaining six objects host M-type giants. The high number ratio of C to M giants in these binaries is consistent with the low metallicity of M33. The spatial and radial velocity distributions of these new symbiotic binaries are consistent with a wide range of progenitor star ages.

  19. Iron uptake by melanoma cells from the soluble form of the transferrin homologue, melanotransferrin.

    Science.gov (United States)

    Food, Michael R; Des Richardson, R

    2002-01-01

    Melanotransferrin (MTf) is a membrane-bound transferrin (Tf) homologue that can also exist in a soluble form (sMTf). Considering the high homology of MTf to Tf, it is possible to suggest that sMTf could bind to the high affinity transferrin receptor 1 (TfR1) or lower affinity TfR2. We have used sMTf labelled with 59Fe to examine its ability to donate Fe to cells. Our experiments demonstrate that sMTf is far less effective than Tf at donating Fe to cells and this does not occur via specific receptors. Indeed, the uptake of sMTf by cells occurred via a non-specific process (e.g. adsorptive pinocytosis).

  20. The Drosophila Kctd-family homologue Kctd12-like modulates male aggression and mating behaviour.

    Science.gov (United States)

    Williams, Michael J; Goergen, Philip; Phad, Ganesh; Fredriksson, Robert; Schiöth, Helgi B

    2014-08-01

    In Drosophila, serotonin (5-HT) regulates aggression, mating behaviour and sleep/wake behaviour through different receptors. Currently, how these various receptors are themselves regulated is still not completely understood. The KCTD12-family of proteins, which have been shown to modify G-protein-coupled receptor (GPCR) signalling in mammals, are one possibility of auxiliary proteins modulating 5-HT receptor signalling. The KCTD12-family was found to be remarkably conserved and present in species from C. elegans to humans. The Drosophila KCTD12 homologue Kctd12-like (Ktl) was highly expressed in both the larval and adult CNS. By performing behavioural assays in male Drosophila, we now reveal that Ktl is required for proper male aggression and mating behaviour. Previously, it was shown that Ktl is in a complex with the Drosophila 5-HT receptor 5-HT7, and we observed that both Ktl and the 5-HT1A receptor are required in insulin-producing cells (IPCs) for proper adult male behaviour, as well as for hyperaggressive activity induced by the mammalian 5-HT1A receptor agonist 8-hydroxy-2-dipropylaminotetralin-hydrobromide. Finally, we show that Ktl expression in the IPCs is necessary to regulate locomotion and normal sleep/wake patterns in Drosophila, but not the 5-HT1A receptor. Similar to what was observed with mammalian KCTD12-family members that interact physically with a GPCR receptor to regulate desensitization, in Drosophila Ktl may function in GPCR 5-HT receptor pathways to regulate their signalling, which is required for proper adult male behaviour. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  1. Detection of a Yersinia pestis gene homologue in rodent samples

    Directory of Open Access Journals (Sweden)

    Timothy A. Giles

    2016-08-01

    Full Text Available A homologue to a widely used genetic marker, pla, for Yersinia pestis has been identified in tissue samples of two species of rat (Rattus rattus and Rattus norvegicus and of mice (Mus musculus and Apodemus sylvaticus using a microarray based platform to screen for zoonotic pathogens of interest. Samples were from urban locations in the UK (Liverpool and Canada (Vancouver. The results indicate the presence of an unknown bacterium that shares a homologue for the pla gene of Yersinia pestis, so caution should be taken when using this gene as a diagnostic marker.

  2. Swift/UVOT Measurements of the UV Dust Extinction Curve and the Recent Star Formation History of the SMC and M33

    Science.gov (United States)

    Hagen, Lea M. Z.; Siegel, Michael; Hoversten, Erik A.; Gronwall, Caryl; Immler, Stefan; Vargas, Angelica

    2017-01-01

    The Swift Ultraviolet/Optical Telescope (UVOT) is uniquely suited to study star formation and dust extinction in nearby galaxies. I will discuss results from the Small Magellanic Cloud (SMC) and M33, for which we have unprecedented observations in three near-UV bands from 1700-3000Å at 2.5" resolution. We combine our UV imaging with archival optical and infrared data to model the spectral energy distributions of individual regions of each galaxy, simultaneously fitting for the dust extinction curve properties, total dust, stellar mass, and age. We have created the first-ever maps of the UV dust extinction curve, which show previously-unconfirmed spatial variation: both the slope and 2175Å bump vary considerably over the face of both the SMC and M33. I will discuss the implications of these results on studies of star formation and galaxy evolution at both low and high redshift.

  3. The Araucaria Project. A Distance Determination to the Local Group Spiral M33 from Near-Infrared Photometry of Cepheid Variables

    CERN Document Server

    Gieren, W; Pietrzynski, G; Konorski, P; Suchomska, K; Graczyk, D; Pilecki, B; Bresolin, F; Kudritzki, R P; Karczmarek, P; Gallenne, A; Calderon, P; Geisler, D

    2013-01-01

    Motivated by an amazing range of reported distances to the nearby Local Group spiral galaxy M33, we have obtained deep near-infrared photometry for 26 long-period Cepheids in this galaxy with the ESO VLT. From the data we constructed period-luminosity relations in the J and K bands which together with previous optical VI photometry for the Cepheids by Macri et al. were used to determine the true distance modulus of M33, and the mean reddening affecting the Cepheid sample with the multiwavelength fit method developed in the Araucaria Project. We find a true distance modulus of 24.62 for M33, with a total uncertainty of +- 0.07 mag which is dominated by the uncertainty on the photometric zero points in our photometry. The reddening is determined as E(B-V)=0.19 +- 0.02, in agreement with the value used by the HST Key Project of Freedman et al. but in some discrepancy with other recent determinations based on blue supergiant spectroscopy and an O-type eclipsing binary which yielded lower reddening values. Our der...

  4. Isolation and characterization of an AGAMOUS homologue from cocoa

    NARCIS (Netherlands)

    Chaidamsari, T.; Sugiarit, H.; Santoso, D.; Angenent, G.C.; Maagd, de R.A.

    2006-01-01

    We report the cloning of a cDNA from TcAG, an AG (Arabidopsis thaliana MADS-box C-type transcription factor gene AGAMOUS) homologue from cocoa (Theobroma cacao L.). TcAG was in the cocoa flower expressed primarily in stamens and ovaries, comparable to AG in Arabidopsis. Additionally, we found that T

  5. Characterization of a Plasmodium falciparum macrophage-migration inhibitory factor homologue.

    Science.gov (United States)

    Cordery, Damien V; Kishore, Uday; Kyes, Sue; Shafi, Mohammed J; Watkins, Katherine R; Williams, Thomas N; Marsh, Kevin; Urban, Britta C

    2007-03-15

    Macrophage-migration inhibitory factor (MIF), one of the first cytokines described, has a broad range of proinflammatory properties. The genome sequencing project of Plasmodium falciparum identified a parasite homologue of MIF. The protein is expressed during the asexual blood stages of the parasite life cycle that cause malarial disease. The identification of a parasite homologue of MIF raised the question of whether it affects monocyte function in a manner similar to its human counterpart. Recombinant P. falciparum MIF (PfMIF) was generated and used in vitro to assess its influence on monocyte function. Antibodies generated against PfMIF were used to determine the expression profile and localization of the protein in blood-stage parasites. Antibody responses to PfMIF were determined in Kenyan children with acute malaria and in control subjects. PfMIF protein was expressed in asexual blood-stage parasites, localized to the Maurer's cleft. In vitro treatment of monocytes with PfMIF inhibited random migration and reduced the surface expression of Toll-like receptor (TLR) 2, TLR4, and CD86. These results indicate that PfMIF is released during blood-stage malaria and potentially modulates the function of monocytes during acute P. falciparum infection.

  6. The identification of extreme asymptotic giant branch stars and red supergiants in M33 with 24 μm variability

    Energy Technology Data Exchange (ETDEWEB)

    Montiel, Edward J.; Clayton, Geoffrey C.; Johnson, Christopher B. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Srinivasan, Sundar [Academica Sinica, Institute of Astronomy and Astrophysics, PO Box 23-141, Taipei 10617, Taiwan, R. O. C. (China); Engelbracht, Charles W., E-mail: emonti2@lsu.edu [Steward Observatory, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)

    2015-02-01

    We present the first detection of 24 μm variability in 24 sources in the Local Group galaxy M33. These results are based on 4 epochs of Multiband Imaging Photometer for Spitzer observations, which are irregularly spaced over ∼750 days. We find that these sources are constrained exclusively to the Holmberg radius of the galaxy, which increases their chances of being members of M33. We have constructed spectral energy distributions (SEDs) ranging from the optical to the submillimeter to investigate the nature of these objects. We find that 23 of our objects are most likely heavily self-obscured, evolved stars, while the remaining source is the Giant H ii region, NGC 604. We believe that the observed variability is the intrinsic variability of the central star reprocessed through their circumstellar dust shells. Radiative transfer modeling was carried out to determine their likely chemical composition, luminosity, and dust production rate (DPR). As a sample, our modeling has determined an average luminosity of (3.8±0.9)×10{sup 4} L{sub ⊙} and a total DPR of (2.3±0.1)×10{sup −5} M{sub ⊙} yr{sup −1}. Most of the sources, given the high DPRs and short wavelength obscuration, are likely extreme asymptotic giant branch (XAGB) stars. Five of the sources are found to have luminosities above the classical AGB limit (M{sub bol} <−7.1 mag, L > 54,000 L{sub ⊙}), which classifies them as probable red supergiants (RSGs). Almost all of the sources are classified as oxygen-rich. As also seen in the LMC, a significant fraction of the dust in M33 is produced by a handful of XAGB and RSG stars.

  7. Monolayer structures of alkyl aldehydes: Odd-membered homologues

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, T.K. [BP Institute, Department of Chemistry, University of Cambridge, Cambridge (United Kingdom); Clarke, S.M., E-mail: stuart@bpi.cam.ac.u [BP Institute, Department of Chemistry, University of Cambridge, Cambridge (United Kingdom); Bhinde, T. [BP Institute, Department of Chemistry, University of Cambridge, Cambridge (United Kingdom); Castro, M.A.; Millan, C. [Instituto Ciencia de los Materiales de Sevilla, Departamento de Quimica Inorganica (CSIC-Universidad de Sevilla) (Spain); Medina, S. [Centro de Investigacion, Tecnologia e Innovacion de la Universidad de Sevilla (CITIUS), Sevilla (Spain)

    2011-03-01

    Crystalline monolayers of three aldehydes with an odd number of carbon atoms in the alkyl chain (C{sub 7}, C{sub 9} and C{sub 11}) at low coverages are observed by a combination of X-ray and neutron diffraction. Analysis of the diffraction data is discussed and possible monolayer crystal structures are proposed; although unique structures could not be ascertained for all molecules. We conclude that the structures are flat on the surface, with the molecules lying in the plane of the layer. The C{sub 11} homologue is determined to have a plane group of either p2, pgb or pgg, and for the C{sub 7} homologue the p2 plane group is preferred.

  8. Characterization of mouse Dach2, a homologue of Drosophila dachshund.

    Science.gov (United States)

    Davis, R J; Shen, W; Sandler, Y I; Heanue, T A; Mardon, G

    2001-04-01

    The Drosophila genes eyeless, eyes absent, sine oculis and dachshund cooperate as components of a network to control retinal determination. Vertebrate homologues of these genes have been identified and implicated in the control of cell fate. We present the cloning and characterization of mouse Dach2, a homologue of dachshund. In situ hybridization studies demonstrate Dach2 expression in embryonic nervous tissues, sensory organs and limbs. This pattern is similar to mouse Dach1, suggesting a partially redundant role for these genes during development. In addition, we determine that Dach2 expression in the forebrain of Pax6 mutants and dermamyotome of Pax3 mutants is not detectably altered. Finally, genetic mapping experiments place mouse Dach2 on the X chromosome between Xist and Esx1. The identification of human DACH2 sequences at Xq21 suggests a possible role for this gene in Allan-Herndon syndrome, Miles-Carpenter syndrome, X-linked cleft palate and/or Megalocornea.

  9. Mammalian homologue of the calcium-sensitive phosphoglycoprotein, parafusin.

    Science.gov (United States)

    Wyroba, E; Widding Høyer, A; Storgaard, P; Satir, B H

    1995-12-01

    Three specific antipeptide antibodies and oligonucleotide probes synthesized to internal sequences of parafusin have been used to search for mammalian counterpart(s) of this protein. Parafusin is an exocytic-sensitive phosphoglycoprotein from a unicellular eukaryote Paramecium that was recently cloned and sequenced (Subramanian et al., Proc. Natl. Acad. Sci. USA 91, 9832-9836 (1994)). Western and Southern blot analyses, polymerase chain reaction (PCR) and reverse transcriptase coupled PCR (RT-PCR) techniques have been used to examine rat liver and pancreas, human pancreas and a murine pancreatic beta-cell line (beta TC3) arising in transgenic mice. The parafusin-specific antibodies showed cross-reaction with a protein at approximately 63 kDa in 4 tissues, whereas a phosphoglucomutase-specific antibody also detected a second band of similar molecular weight in the beta TC3 cells. The presence of two bands shows that parafusin homologue(s) and phosphoglucomutase are separate entities. beta TC3 cells were shown to incorporate [beta 35]UDPGlc into the parafusin homologue in a Ca(++)-sensitive manner characteristic of parafusin. Southern blot analysis revealed that the parafusin-specific probe hybridized with restriction enzyme digests of rat DNA in distinct patterns different from those observed with a phosphoglucomutase-specific probe. Rat genomic DNA and mRNA from the beta TC3 cells were used as the templates for PCR and RT-PCR using internal parafusin primers. In both cases similarly sized products were obtained which hybridized in Southern analysis with a specific parafusion probe located within the amplified region. These results indicate that a parafusin homologue exists in mammalian cells.

  10. Luminous and Variable Stars in M31 and M33. II. Luminous Blue Variables, Candidate LBVs, Fe II Emission Line Stars, and Other Supergiants

    CERN Document Server

    Humphreys, Roberta M; Davidson, Kris; Bomans, D J; Burggraf, Birgitta

    2014-01-01

    An increasing number of non-terminal eruptions are being found in the numerous surveys for optical transients. Very little is known about these giant eruptions, their progenitors and their evolutionary state. A greatly improved census of the likely progenitor class, including the most luminous evolved stars, the Luminous Blue Varaibles (LBVs), and the warm and cool hypergiants is now needed for a complete picture of the final pre-SN stages of very massive stars. We have begun a survey of the evolved and un stable luminous star populations in several nearby resolved galaxies. In this second paper on M31 and M33, we review the spectral characteristics, spectral energy distributions, circumstellar ejecta, and evidence for mass loss for 82 luminous and variable stars.We show that many of these stars have warm circumstellar dust including several of the Fe II emission line stars, but conclude that the confirmed LBVs in M31 and M33 do not. The confirmed LBVs have relatively low wind speeds even in their hot, quiesc...

  11. Understanding Radio-Selected Thermal Sources in M 33: Ultraviolet, Optical, Near-Infrared, Spitzer Mid-Infrared, and Radio Observations

    CERN Document Server

    Buckalew, B A; Darnel, J M; Polomski, E; Gehrz, R D; Humphreys, R M; Woodward, C E; Hinz, J L; Engelbracht, C W; Gordon, K D; Misselt, K; Pérez-González, P G; Rieke, G H; Willner, S P; Ashby, M L N; Barmby, P; Pahre, M A; Roellig, T L; Devereux, N; Van Loon, J T; Brandl, B; Buckalew, Brent A.; Kobulnicky, Henry A.; Darnel, Jonathan M.; Polomski, Elisha; Gehrz, Robert D.; Humphreys, Roberta M.; Woodward, Charles E.; Hinz, Joannah L.; Gordon, Karl D.; Rieke, George H.; Devereux, Nick; Loon, Jacco Th. Van

    2005-01-01

    We present ultraviolet, optical, near-infrared, Spitzer mid-infrared, and radio images of 14 radio-selected objects in M 33. These objects are thought to represent the youngest phase of star cluster formation. We have detected the majority of cluster candidates in M 33 at all wavelengths. From the near-IR images, we derived ages 2-10 Myr, K_S-band extinctions (A_K_S) of 0-1 mag, and stellar masses of 10^3-10^4 M_solar. We have generated spectral energy distributions (SEDs) of each cluster from 0.1 micron to 160 microns. From these SEDs, we have modeled the dust emission around these star clusters to determine the dust masses (1-10^3 M_solar) and temperatures (40-90 K) of the clusters' local interstellar medium. Extinctions derived from the JHK_S, Halpha, and UV images are similar to within a factor of 2 or 3. These results suggest that eleven of the fourteen radio-selected objects are optically-visible young star clusters with a surrounding H II region, that two are background objects, possibly AGN, and that ...

  12. In vitro dentine remineralization with a potential salivary phosphoprotein homologue.

    Science.gov (United States)

    Romero, Maria Jacinta Rosario H; Nakashima, Syozi; Nikaido, Toru; Sadr, Alireza; Tagami, Junji

    2016-08-01

    Advantages of introducing a salivary phosphoprotein homologue under standardized in vitro conditions to simulate the mineral-stabilizing properties of saliva have been proposed. This study longitudinally investigates the effects of casein, incorporated as a potential salivary phosphoprotein homologue in artificial saliva (AS) solutions with/without fluoride (F) on in vitro dentine lesion remineralization. Thin sections of bovine root dentine were demineralized and allocated randomly into 6 groups (n=18) having equivalent mineral loss (ΔZ) after transverse microradiography (TMR). The specimens were remineralized using AS solutions containing casein 0μg/ml, F 0ppm (C0-F0); casein 0μg/ml, F 1ppm (C0-F1); casein 10μg/ml, F 0ppm (C10-F0); casein 10μg/ml, F 1ppm (C10-F1); casein 100μg/ml, F 0ppm (C100-F0) or casein 100μg/ml, F 1ppm (C100-F1) for 28days with TMR taken every 7 days. Surface mineral precipitation, evident in group C0-F1, was apparently inhibited in groups with casein incorporation. Repeated measures ANOVA with Bonferroni correction revealed higher ΔZ for non-F and non-casein groups than for their counterparts (p<0.001). Subsequent multiple comparisons showed that mineral gain was higher (p<0.001) with 10μg/ml casein than with 100μg/ml when F was present in the earlier stages of remineralization, with both groups achieving almost complete remineralization after 28 days. Casein is a potential salivary phosphoprotein homologue that could be employed for in vitro dentine remineralization studies. Concentration related effects may be clinically significant and thus must be further examined. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Gas surface density, star formation rate surface density, and the maximum mass of young star clusters in a disk galaxy. I. The flocculent galaxy M33

    CERN Document Server

    Gonzalez-Lopezlira, Rosa A; Kroupa, Pavel

    2012-01-01

    We analyze the relationship between maximum cluster mass, M_max, and surface densities of total gas (Sigma_gas), molecular gas (Sigma_H2) and star formation rate (Sigma_SFR) in the flocculent galaxy M33, using published gas data and a catalog of more than 600 young star clusters in its disk. By comparing the radial distributions of gas and most massive cluster masses, we find that M_max is proportional to Sigma_gas^4.7, M_max is proportional Sigma_H2^1.3, and M_max is proportional to Sigma_SFR^1.0. We rule out that these correlations result from the size of sample; hence, the change of the maximum cluster mass must be due to physical causes.

  14. Cloning of an agr homologue of Staphylococcus saprophyticus.

    Science.gov (United States)

    Sakinc, Türkan; Kulczak, Pawel; Henne, Karsten; Gatermann, Sören G

    2004-08-01

    An agr homologue of Staphylococcus saprophyticus was identified, cloned and sequenced. The gene locus shows homologies to other staphylococcal agr systems, especially to those of S. epidermidis and S. lugdunensis. A putative RNAIII was identified and found to be differentially expressed during the growth phases. In contrast to the RNAIII molecules of S. epidermidis and S. aureus it does not contain an open reading frame that codes for a protein with homologies to the delta-toxin. Using PCR, the agr was found to be present in clinical isolates of S. saprophyticus.

  15. receptores

    Directory of Open Access Journals (Sweden)

    Salete Regina Daronco Benetti

    2006-01-01

    Full Text Available Se trata de un estudio etnográfico, que tuvo lo objetivo de interpretar el sistema de conocimiento y del significado atribuidos a la sangre referente a la transfusión sanguínea por los donadores y receptores de un banco de sangre. Para la colecta de las informaciones se observaron los participantes y la entrevista etnográfica se realizó el análisis de dominio, taxonómicos y temáticos. Los dominios culturales fueron: la sangre es vida: fuente de vida y alimento valioso; creencias religiosas: fuentes simbólicas de apoyos; donación sanguínea: un gesto colaborador que exige cuidarse, gratifica y trae felicidad; donación sanguínea: fuente simbólica de inseguridad; estar enfermo es una condición para realizar transfusión sanguínea; transfusión sanguínea: esperanza de vida; Creencias populares: transfusión sanguínea como riesgo para la salud; donadores de sangre: personas benditas; donar y recibir sangre: como significado de felicidad. Temática: “líquido precioso que origina, sostiene, modifica la vida, provoca miedo e inseguridad”.

  16. Luminous and Variable Stars in M31 and M33. III. The Yellow and Red Supergiants and Post-red Supergiant Evolution

    Science.gov (United States)

    Gordon, Michael S.; Humphreys, Roberta M.; Jones, Terry J.

    2016-07-01

    Recent supernova (SN) and transient surveys have revealed an increasing number of non-terminal stellar eruptions. Though the progenitor class of these eruptions includes the most luminous stars, little is known of the pre-SN mechanics of massive stars in their most evolved state, thus motivating a census of possible progenitors. From surveys of evolved and unstable luminous star populations in nearby galaxies, we select a sample of yellow and red supergiant (RSG) candidates in M31 and M33 for review of their spectral characteristics and spectral energy distributions (SEDs). Since the position of intermediate- and late-type supergiants on the color-magnitude diagram can be heavily contaminated by foreground dwarfs, we employ spectral classification and multi-band photometry from optical and near-infrared surveys to confirm membership. Based on spectroscopic evidence for mass loss and the presence of circumstellar (CS) dust in their SEDs, we find that 30%-40% of the yellow supergiants are likely in a post-RSG state. Comparison with evolutionary tracks shows that these mass-losing, post-RSGs have initial masses between 20 and 40 M ⊙. More than half of the observed RSGs in M31 and M33 are producing dusty CS ejecta. We also identify two new warm hypergiants in M31, J004621.05+421308.06 and J004051.59+403303.00, both of which are likely in a post-RSG state. Based on observations obtained with the Large Binocular Telescope (LBT), an international collaboration among institutions in the United States, Italy, and Germany. LBT Corporation partners are: The University of Arizona on behalf of the Arizona university system; Istituto Nazionale di Astrofisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University; The Ohio State University, and The Research Corporation, on behalf of The University of Notre Dame, University of Minnesota, and University of Virginia.

  17. Alkylresorcinol content and homologue composition in durum wheat (Triticum durum) kernels and pasta products.

    Science.gov (United States)

    Landberg, Rikard; Kamal-Eldin, Afaf; Andersson, Roger; Aman, Per

    2006-04-19

    The total alkylresorcinol (AR) content and relative homologue composition of 21 durum wheat (Triticum durum) kernel samples, as well as 5 pasta products and the corresponding flour mixtures, were determined. Durum wheat contained on average 455 microg/g ARs, and the average relative homologue composition was C17:0 (0.4%), C19:0 (14%), C21:0 (58%), C23:0 (21%), and C25:0 (6.5%). The homologue composition was found to be relatively consistent among samples, with durum wheat being different from common wheat by having a higher proportion of the longer homologues. No differences in content or homologue composition were observed in pasta products compared to flour ingredients, showing that alkylresorcinols are stable during pasta processing. The ratio of the homologues C17:0 to C21:0 was wheat products, which is different from those of common wheat (0.1) and rye (0.9).

  18. Structure of a DsbF homologue from Corynebacterium diphtheriae.

    Science.gov (United States)

    Um, Si-Hyeon; Kim, Jin-Sik; Lee, Kangseok; Ha, Nam-Chul

    2014-09-01

    Disulfide-bond formation, mediated by the Dsb family of proteins, is important in the correct folding of secreted or extracellular proteins in bacteria. In Gram-negative bacteria, disulfide bonds are introduced into the folding proteins in the periplasm by DsbA. DsbE from Escherichia coli has been implicated in the reduction of disulfide bonds in the maturation of cytochrome c. The Gram-positive bacterium Mycobacterium tuberculosis encodes DsbE and its homologue DsbF, the structures of which have been determined. However, the two mycobacterial proteins are able to oxidatively fold a protein in vitro, unlike DsbE from E. coli. In this study, the crystal structure of a DsbE or DsbF homologue protein from Corynebacterium diphtheriae has been determined, which revealed a thioredoxin-like domain with a typical CXXC active site. Structural comparison with M. tuberculosis DsbF would help in understanding the function of the C. diphtheriae protein.

  19. RCT photometry of the Hubble Classical Cepheid V19 in M33: Evidence for the Cessation of Pulsations - A Case of Stellar Evolution in Real Time

    Science.gov (United States)

    Engle, Scott G.; Guinan, Edward F.; Macri, Lucas; Pellerin, Ann

    2011-03-01

    We report on our continuing efforts to monitor the photometric behavior of Hubble's Variable Star V19 in the Triangulum Spiral Galaxy M33. B,V photometry has been carried out of this unusual 18th mag (previous) Cepheid with the 1.3-m RCT (Robotically Controlled Telescope) at KPNO. With time-series photometry, with a dedicated robotic telescope, we can hope to solve the mystery of V19 and its unprecedented evolutionary behavior. In the influential work "A Spiral Nebula as a Stellar System: Messier 33" (Hubble 1926) Edwin Hubble determined the distance to M33 by using 35 Cepheids he discovered. One of those Cepheids was designated V19. At that time observations revealed V19 to have a 54.7-day period and B-band (converted from photographic magnitudes) light amplitude of 1.1-mag. Its mean B-magnitude was 19.6 /-0.2. V19 properties were consistent with the Period-Luminosity Law for M33 derived by Hubble at that time. Follow-up observations in 1996-1997 as part of the DIRECT Program (Macri et al. 2001), however, revealed large and surprising changes in the properties of V19. Its mean B-magnitude had risen to 19.05 /-0.05 and its amplitude had decreased to less than 0.1-mag. The DIRECT study thoroughly checked for possible misclassifications of the variable or contamination by nearby objects, and found none. For all intents and purposes, V19 is no longer a Classical Cepheid, or at least varying below the detectable levels of the photometry. The only other well-documented instance of Cepheid pulsations declining over time is in the case of Polaris - whose V-band amplitude decreased from just over 0.1-mag to below 0.03-mag over the course of a century (Engle et al 2004). Also, a study of the visual magnitudes of Polaris over the past two millennia has shown a possible increase in brightness of 1-mag over the past 1000 years. The changes observed for V19 are obviously on a much more dramatic scale. We discuss the properties of this unusual (former) Cepheid and discuss

  20. Structure of a bacterial homologue of vitamin K epoxide reductase

    Energy Technology Data Exchange (ETDEWEB)

    Li, Weikai; Schulman, Sol; Dutton, Rachel J.; Boyd, Dana; Beckwith, Jon; Rapoport, Tom A. (Harvard-Med); (HHMI)

    2010-03-19

    Vitamin K epoxide reductase (VKOR) generates vitamin K hydroquinone to sustain {gamma}-carboxylation of many blood coagulation factors. Here, we report the 3.6 {angstrom} crystal structure of a bacterial homologue of VKOR from Synechococcus sp. The structure shows VKOR in complex with its naturally fused redox partner, a thioredoxin-like domain, and corresponds to an arrested state of electron transfer. The catalytic core of VKOR is a four transmembrane helix bundle that surrounds a quinone, connected through an additional transmembrane segment with the periplasmic thioredoxin-like domain. We propose a pathway for how VKOR uses electrons from cysteines of newly synthesized proteins to reduce a quinone, a mechanism confirmed by in vitro reconstitution of vitamin K-dependent disulphide bridge formation. Our results have implications for the mechanism of the mammalian VKOR and explain how mutations can cause resistance to the VKOR inhibitor warfarin, the most commonly used oral anticoagulant.

  1. Isolation and characterization of the human MRE11 homologue

    Energy Technology Data Exchange (ETDEWEB)

    Petrini, J.H.J.; Walsh, M.E.; DiMare, C. [Harvard Medical School, Boston, MA (United States)] [and others

    1995-09-01

    Mutation of the Saccharomyces cerevisiae RAD52 epistasis group gene, MRE11, blocks meiotic recombination, confers profound sensitivity to double-strand break damage, and has a hyperrecombinational phenotype in mitotic cells. We isolated a highly conserved human MRE11 homologue using a two-hybrid screen for DNA ligase I-interacting proteins. Human MRE11 shares approximately 50% identity with its yeast counterpart over the N-terminal half of the protein. MRE11 is expressed at the highest levels in proliferating tissues, but is also observed in other tissues. The MRE11 locus maps to human chromosome 11q21 in a region frequently associated with cancer-related chromosomal abnormalities. A MRE11-related locus was found on chromosome 7q11.2-q11.3. 60 refs., 4 figs.

  2. Luminous and Variable Stars in M31 and M33. III. The Yellow and Red Supergiants and Post-Red Supergiant Evolution

    CERN Document Server

    Gordon, Michael S; Jones, Terry J

    2016-01-01

    Recent supernova and transient surveys have revealed an increasing number of non-terminal stellar eruptions. Though the progenitor class of these eruptions includes the most luminous stars, little is known of the pre-supernova mechanics of massive stars in their most evolved state, thus motivating a census of possible progenitors. From surveys of evolved and unstable luminous star populations in nearby galaxies, we select a sample of yellow and red supergiant candidates in M31 and M33 for review of their spectral characteristics and spectral energy distributions. Since the position of intermediate and late-type supergiants on the color-magnitude diagram can be heavily contaminated by foreground dwarfs, we employ spectral classification and multi-band photometry from optical and near-infrared surveys to confirm membership. Based on spectroscopic evidence for mass loss and the presence of circumstellar dust in their SEDs, we find that $30-40\\%$ of the yellow supergiants are likely in a post-red supergiant state...

  3. A new evolutionary scenario for the formation of massive black-hole binaries such as M33 X-7 and IC 10 X-1

    CERN Document Server

    de Mink, S E; Langer, N; Pols, O R; Yoon, S -Ch

    2009-01-01

    The formation of close massive black-hole binaries is a challenge for binary evolutionary models, especially the intriguing system M33 X-7 which harbours one of the most massive stellar-mass black holes (16 solar masses) orbiting a 70 solar mass O-star every 3.5 days. In standard binary evolution theory an episode of mass transfer or common envelope is inevitable in a binary with such a small orbital period, which complicates the formation of a black hole with such a high mass. To explain this system, we discuss a new binary evolution channel (De Mink et al. 2009), in which rotational mixing plays an important role. In very massive close binaries, tides force the rotation rate of the stars to be so high that rotationally induced mixing becomes very efficient. Helium produced in the center is mixed throughout the envelope. Instead of expanding during their mainsequence evolution (with the inevitable consequence of mass transfer), these stars stay compact, and avoid filling their Roche lobe. They gradually evol...

  4. The spiral galaxy M33 mapped in the FIR by ISOPHOT: A spatially resolved study of the warm and cold dust

    CERN Document Server

    Hippelein, H; Tuffs, R J; Lemke, D; Stickel, M; Klaas, U; Völk, H J

    2003-01-01

    The Sc galaxy M33 has been mapped with ISOPHOT in the far-infrared, at 60, 100, and 170mue. The spatial resolution of these FIR maps allows the separation of spiral arms and interarm regions and the isolation of a large number of star-forming regions. The spectral energy distribution in the FIR indicates a superposition of two components, a warm one originating from dust at ~45K, and a cold one, at ~16K. The warm component is concentrated towards the spiral arms and the star-forming regions, and is likely heated by the UV radiation from OB stars. The cold component is more smoothly distributed over the disk, and heated by the diffuse interstellar radiation. For the about 60 star-forming regions detected the H-alpha/FIR flux ratio increases significantly with the distance from the galaxy center, probably due to decreasing extinction. An anti-correlation of F_Ha/F_60 with F_170 suggests the intrinsic extinction to be related to the cold dust surface brightness according to A_V/S_170~0.03mag/MJy*sr. For the tota...

  5. Luminous and Variable Stars in M31 and M33. IV. Luminous Blue Variables, Candidate LBVs, and the B[e] Supergiants; How to Tell Them Apart

    CERN Document Server

    Humphreys, Roberta M; Martin, John C; Weis, Kerstin; Hahn, David

    2016-01-01

    In this series of papers we have presented the results of a spectroscopic survey of luminous and variable stars in the nearby spirals M31 and M33. In this paper, we present spectroscopy of 132 additional luminous stars, variables, and emission line objects. Most of the stars have emission line spectra, including LBVs and candidate LBVs, Fe II emission line stars and the B[e] supergiants, and the warm hypergiants. Many of these objects are spectroscopically similar and are often confused with each other. With this large spectroscopic data set including various types of emission line stars, we examine their similarities and differences and propose the following criteria that can be used to help distinguish these stars in future work: 1. The B[e] supergiants have emission lines of [O I] and [Fe II] in their spectra. Most of the spectroscopically confirmed sgB[e] stars also have warm circumstellar dust in their SEDs. 2. Confirmed LBVs do not have the [O I] emission lines in their spectra. Some LBVs have [Fe II] e...

  6. The Drosophila homologue of the amyloid precursor protein is a conserved modulator of Wnt PCP signaling.

    Directory of Open Access Journals (Sweden)

    Alessia Soldano

    Full Text Available Wnt Planar Cell Polarity (PCP signaling is a universal regulator of polarity in epithelial cells, but it regulates axon outgrowth in neurons, suggesting the existence of axonal modulators of Wnt-PCP activity. The Amyloid precursor proteins (APPs are intensely investigated because of their link to Alzheimer's disease (AD. APP's in vivo function in the brain and the mechanisms underlying it remain unclear and controversial. Drosophila possesses a single APP homologue called APP Like, or APPL. APPL is expressed in all neurons throughout development, but has no established function in neuronal development. We therefore investigated the role of Drosophila APPL during brain development. We find that APPL is involved in the development of the Mushroom Body αβ neurons and, in particular, is required cell-autonomously for the β-axons and non-cell autonomously for the α-axons growth. Moreover, we find that APPL is a modulator of the Wnt-PCP pathway required for axonal outgrowth, but not cell polarity. Molecularly, both human APP and fly APPL form complexes with PCP receptors, thus suggesting that APPs are part of the membrane protein complex upstream of PCP signaling. Moreover, we show that APPL regulates PCP pathway activation by modulating the phosphorylation of the Wnt adaptor protein Dishevelled (Dsh by Abelson kinase (Abl. Taken together our data suggest that APPL is the first example of a modulator of the Wnt-PCP pathway specifically required for axon outgrowth.

  7. The Drosophila homologue of the amyloid precursor protein is a conserved modulator of Wnt PCP signaling.

    Science.gov (United States)

    Soldano, Alessia; Okray, Zeynep; Janovska, Pavlina; Tmejová, Kateřina; Reynaud, Elodie; Claeys, Annelies; Yan, Jiekun; Atak, Zeynep Kalender; De Strooper, Bart; Dura, Jean-Maurice; Bryja, Vítězslav; Hassan, Bassem A

    2013-01-01

    Wnt Planar Cell Polarity (PCP) signaling is a universal regulator of polarity in epithelial cells, but it regulates axon outgrowth in neurons, suggesting the existence of axonal modulators of Wnt-PCP activity. The Amyloid precursor proteins (APPs) are intensely investigated because of their link to Alzheimer's disease (AD). APP's in vivo function in the brain and the mechanisms underlying it remain unclear and controversial. Drosophila possesses a single APP homologue called APP Like, or APPL. APPL is expressed in all neurons throughout development, but has no established function in neuronal development. We therefore investigated the role of Drosophila APPL during brain development. We find that APPL is involved in the development of the Mushroom Body αβ neurons and, in particular, is required cell-autonomously for the β-axons and non-cell autonomously for the α-axons growth. Moreover, we find that APPL is a modulator of the Wnt-PCP pathway required for axonal outgrowth, but not cell polarity. Molecularly, both human APP and fly APPL form complexes with PCP receptors, thus suggesting that APPs are part of the membrane protein complex upstream of PCP signaling. Moreover, we show that APPL regulates PCP pathway activation by modulating the phosphorylation of the Wnt adaptor protein Dishevelled (Dsh) by Abelson kinase (Abl). Taken together our data suggest that APPL is the first example of a modulator of the Wnt-PCP pathway specifically required for axon outgrowth.

  8. Homologue Pairing in Flies and Mammals: Gene Regulation When Two Are Involved

    Directory of Open Access Journals (Sweden)

    Manasi S. Apte

    2012-01-01

    Full Text Available Chromosome pairing is usually discussed in the context of meiosis. Association of homologues in germ cells enables chromosome segregation and is necessary for fertility. A few organisms, such as flies, also pair their entire genomes in somatic cells. Most others, including mammals, display little homologue pairing outside of the germline. Experimental evidence from both flies and mammals suggests that communication between homologues contributes to normal genome regulation. This paper will contrast the role of pairing in transmitting information between homologues in flies and mammals. In mammals, somatic homologue pairing is tightly regulated, occurring at specific loci and in a developmentally regulated fashion. Inappropriate pairing, or loss of normal pairing, is associated with gene misregulation in some disease states. While homologue pairing in flies is capable of influencing gene expression, the significance of this for normal expression remains unknown. The sex chromosomes pose a particularly interesting situation, as females are able to pair X chromosomes, but males cannot. The contribution of homologue pairing to the biology of the X chromosome will also be discussed.

  9. Phosphatase and Tensin Homologue: Novel Regulation by Developmental Signaling

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    Travis J. Jerde

    2015-01-01

    Full Text Available Phosphatase and tensin homologue (PTEN is a critical cell endogenous inhibitor of phosphoinositide signaling in mammalian cells. PTEN dephosphorylates phosphoinositide trisphosphate (PIP3, and by so doing PTEN has the function of negative regulation of Akt, thereby inhibiting this key intracellular signal transduction pathway. In numerous cell types, PTEN loss-of-function mutations result in unopposed Akt signaling, producing numerous effects on cells. Numerous reports exist regarding mutations in PTEN leading to unregulated Akt and human disease, most notably cancer. However, less is commonly known about nonmutational regulation of PTEN. This review focuses on an emerging literature on the regulation of PTEN at the transcriptional, posttranscriptional, translational, and posttranslational levels. Specifically, a focus is placed on the role developmental signaling pathways play in PTEN regulation; this includes insulin-like growth factor, NOTCH, transforming growth factor, bone morphogenetic protein, wnt, and hedgehog signaling. The regulation of PTEN by developmental mediators affects critical biological processes including neuronal and organ development, stem cell maintenance, cell cycle regulation, inflammation, response to hypoxia, repair and recovery, and cell death and survival. Perturbations of PTEN regulation consequently lead to human diseases such as cancer, chronic inflammatory syndromes, developmental abnormalities, diabetes, and neurodegeneration.

  10. Characterization of Major Surface Protease Homologues of Trypanosoma congolense

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    Veronica Marcoux

    2010-01-01

    Full Text Available Trypanosomes encode a family of proteins known as Major Surface Metalloproteases (MSPs. We have identified six putative MSPs encoded within the partially sequenced T. congolense genome. Phylogenic analysis indicates that T. congolense MSPs belong to five subfamilies that are conserved among African trypanosome species. Molecular modeling, based on the known structure of Leishmania Major GP63, reveals subfamily-specific structural variations around the putative active site despite conservation of overall structure, suggesting that each MSP subfamily has evolved to recognize distinct substrates. We have cloned and purified a protein encoding the amino-terminal domain of the T. congolense homologue TcoMSP-D (most closely related to Leishmania GP63. We detect TcoMSP-D in the serum of T. congolense-infected mice. Mice immunized with the amino-terminal domain of TcoMSP-D generate a persisting IgG1 antibody response. Surprisingly, a low-dose challenge of immunized mice with T. congolense significantly increases susceptibility to infection, indicating that immunity to TcoMSP-D is a factor affecting virulence.

  11. IL-2R{gamma} gene microdeletion demonstrates that canine X-linked severe combined immunodeficiency is a homologue of the human disease

    Energy Technology Data Exchange (ETDEWEB)

    Henthorn, P.S.; Fimiani, V.M.; Patterson, D.F. [Univ. of Pennsylvania School of Veterinary Medicine, Philadelphia, PA (United States)] [and others

    1994-09-01

    X-linked severe combined immunodeficiency (SCID) is characterized by profound defects in cellular and humoral immunity and, in humans, is associated with mutations in the gene for the {gamma} chain of the IL-2 receptor (IL-2R{gamma}). We have examined this gene in a colony of dogs established from a single X-linked SCID carrier female. Affected dogs have a 4-bp deletion in the first exon of the IL-2R{gamma} gene, which precludes the production of a functional protein, demonstrating that the canine disease is a true homologue of human X-linked SCID. 37 refs., 3 figs.

  12. Mycosphaerella graminicola LysM effector-mediated stealth pathogenesis subverts recognition through both CERK1 and CEBiP homologues in wheat.

    Science.gov (United States)

    Lee, Wing-Sham; Rudd, Jason J; Hammond-Kosack, Kim E; Kanyuka, Kostya

    2014-03-01

    Fungal cell-wall chitin is a well-recognized pathogen-associated molecular pattern. Recognition of chitin in plants by pattern recognition receptors activates pathogen-triggered immunity (PTI). In Arabidopsis, this process is mediated by a plasma membrane receptor kinase, CERK1, whereas in rice, a receptor-like protein, CEBiP, in addition to CERK1 is required. Secreted chitin-binding lysin motif (LysM) containing fungal effector proteins, such as Ecp6 from the biotrophic fungus Cladosporium fulvum, have been reported to interfere with PTI. Here, we identified wheat homologues of CERK1 and CEBiP and investigated their role in the interaction with the nonbiotrophic pathogen of wheat Mycosphaerella graminicola (synonym Zymoseptoria tritici). We show that silencing of either CERK1 or CEBiP in wheat, using Barley stripe mosaic virus-mediated virus-induced gene silencing, is sufficient in allowing leaf colonization by the normally nonpathogenic M. graminicola Mg3LysM (homologue of Ecp6) deletion mutant, while the Mg1LysM deletion mutant was fully pathogenic toward both silenced and wild-type wheat leaves. These data indicate that Mg3LysM is important for fungal evasion of PTI in wheat leaf tissue and that both CERK1 and CEBiP are required for activation of chitin-induced defenses, a feature conserved between rice and wheat, and perhaps, also in other cereal species.

  13. [Patterns of PCDD/Fs, PCBs and PCNs homologues in fly ash from cement kilns].

    Science.gov (United States)

    Zhang, Jing; Ni, Yu-Wen; Zhang, Hai-Jun; Zhang, Xue-Ping; Zhang, Qing; Chen, Ji-Ping

    2009-02-15

    The concentrations and toxic equivalent (TEQ) values of PCDD/Fs, PCBs and PCNs in fly ash collected from three types of cement kilns (vertical shaft kiln, wet-process rotary kiln and dry-process rotary kiln) and two types of waste incinerators were determined, and the patterns of homologues and congeners were compared. The results showed that the total TEQ of PCDD/Fs, PCBs and PCNs in cement kiln fly ash, which were in the range of 4.0-62, 0.069-3.9 and 0.47-2.8 ng x kg(-1) respectively, were much lower than that of fly ash from waste incinerators. In cement kiln fly ash, the predominating PCDD/Fs homologues were TCDFs, and the chief 2, 3, 7, 8-PCDD/Fs congeners were OCDD, 2, 3, 7, 8-TCDF and 1, 2, 3, 4, 6, 7, 8-HpCDF. The patterns of PCBs homologues in cement kiln fly ash were similar to those of waste incinerators in which TeCB were predominating homologues. PCB77, PCB105, PCB118 were at higher concentrations than other co-polar PCBs. Different types of cement kiln fly ash presented similar PCNs homologue patterns. The predominant homologues were TeCN, whereas OcCN were not detected. PCN 66/67 which has dioxin like toxity was the most abundant congener in all fly ash.

  14. Phosphatase and tensin homologue deleted on chromosome 10

    Directory of Open Access Journals (Sweden)

    Imran Haruna Abdulkareem

    2013-01-01

    Full Text Available Phosphatase and tensin homologue deleted on chromosome 10 (PTEN is a tumor suppressor gene deleted or mutated in many human cancers such as glioblastoma, spinal tumors, prostate, bladder, adrenals, thyroid, breast, endometrium, and colon cancers. They result from loss of heterozygosity (LOH for the PTEN gene on chromosome 10q23. Previous studies reported that various drugs, chemicals, and foods can up-regulate PTEN mRNA and protein expression in different cell lines, and they may be useful in the future prevention and/or treatment of these cancers. PTEN has also been observed to have prognostic significance and is gradually being accepted as an independent prognostic factor. This will help in monitoring disease progression and/or recurrence, with a view to improving treatment outcomes and reducing the associated morbidity and mortality from these cancers. Neprilysin (NEP is a zinc-dependent metallopeptidase that cleaves and inactivates some biologically active peptides thus switching off signal transduction at the cell surface. Decreased NEP expression in many cancers has been reported. NEP can form a complex with PTEN and enhance PTEN recruitment to the plasma membrane as well as stabilize its phosphatase activity. MicroRNA-21 (miR-21 post-transcriptionally down-regulates the expression of PTEN and stimulates growth and invasion in non-small cell lung cancer (NSCLC (lung Ca, suggesting that this may be a potential therapeutic target in the future treatment of NSCLC. PTEN is a tumor suppressor gene associated with many human cancers. This has diagnostic, therapeutic, and prognostic significance in the management of many human cancers, and may be a target for new drug development in the future.

  15. The human homologue of macaque area V6A.

    Science.gov (United States)

    Pitzalis, S; Sereno, M I; Committeri, G; Fattori, P; Galati, G; Tosoni, A; Galletti, C

    2013-11-15

    In macaque monkeys, V6A is a visuomotor area located in the anterior bank of the POs, dorsal and anterior to retinotopically-organized extrastriate area V6 (Galletti et al., 1996). Unlike V6, V6A represents both contra- and ipsilateral visual fields and is broadly retinotopically organized (Galletti et al., 1999b). The contralateral lower visual field is over-represented in V6A. The central 20°-30° of the visual field is mainly represented dorsally (V6Ad) and the periphery ventrally (V6Av), at the border with V6. Both sectors of area V6A contain arm movement-related cells, active during spatially-directed reaching movements (Gamberini et al., 2011). In humans, we previously mapped the retinotopic organization of area V6 (Pitzalis et al., 2006). Here, using phase-encoded fMRI, cortical surface-based analysis and wide-field retinotopic mapping, we define a new cortical region that borders V6 anteriorly and shows a clear over-representation of the contralateral lower visual field and the periphery. As with macaque V6A, the eccentricity increases moving ventrally within the area. The new region contains a non-mirror-image representation of the visual field. Functional mapping reveals that, as in macaque V6A, the new region, but not the nearby area V6, responds during finger pointing and reaching movements. Based on similarity in position, retinotopic properties, functional organization and relationship with the neighboring extrastriate visual areas, we propose that the new cortical region is the human homologue of macaque area V6A.

  16. Antidepressant Binding Site in a Bacterial Homologue of Neurotransmitter Transporters

    Energy Technology Data Exchange (ETDEWEB)

    Singh,S.; Yamashita, A.; Gouaux, E.

    2007-01-01

    Sodium-coupled transporters are ubiquitous pumps that harness pre-existing sodium gradients to catalyse the thermodynamically unfavourable uptake of essential nutrients, neurotransmitters and inorganic ions across the lipid bilayer. Dysfunction of these integral membrane proteins has been implicated in glucose/galactose malabsorption, congenital hypothyroidism, Bartter's syndrome, epilepsy, depression, autism and obsessive-compulsive disorder. Sodium-coupled transporters are blocked by a number of therapeutically important compounds, including diuretics, anticonvulsants and antidepressants, many of which have also become indispensable tools in biochemical experiments designed to probe antagonist binding sites and to elucidate transport mechanisms. Steady-state kinetic data have revealed that both competitive and noncompetitive modes of inhibition exist. Antagonist dissociation experiments on the serotonin transporter (SERT) have also unveiled the existence of a low-affinity allosteric site that slows the dissociation of inhibitors from a separate high-affinity site. Despite these strides, atomic-level insights into inhibitor action have remained elusive. Here we screen a panel of molecules for their ability to inhibit LeuT, a prokaryotic homologue of mammalian neurotransmitter sodium symporters, and show that the tricyclic antidepressant (TCA) clomipramine noncompetitively inhibits substrate uptake. Cocrystal structures show that clomipramine, along with two other TCAs, binds in an extracellular-facing vestibule about 11 {angstrom} above the substrate and two sodium ions, apparently stabilizing the extracellular gate in a closed conformation. Off-rate assays establish that clomipramine reduces the rate at which leucine dissociates from LeuT and reinforce our contention that this TCA inhibits LeuT by slowing substrate release. Our results represent a molecular view into noncompetitive inhibition of a sodium-coupled transporter and define principles for the

  17. Su(dx) E3 ubiquitin ligase-dependent and -independent functions of polychaetoid, the Drosophila ZO-1 homologue.

    Science.gov (United States)

    Djiane, Alexandre; Shimizu, Hideyuki; Wilkin, Marian; Mazleyrat, Sabine; Jennings, Martin D; Avis, Johanna; Bray, Sarah; Baron, Martin

    2011-01-10

    Zona occludens (ZO) proteins are molecular scaffolds localized to cell junctions, which regulate epithelial integrity in mammals. Using newly generated null alleles, we demonstrate that polychaetoid (pyd), the unique Drosophila melanogaster ZO homologue, regulates accumulation of adherens junction-localized receptors, such as Notch, although it is dispensable for epithelial polarization. Pyd positively regulates Notch signaling during sensory organ development but acts negatively on Notch to restrict the ovary germline stem cell niche. In both contexts, we identify a core antagonistic interaction between Pyd and the WW domain E3 ubiquitin ligase Su(dx). Pyd binds Su(dx) directly, in part through a noncanonical WW-binding motif. Pyd also restricts epithelial wing cell numbers to control adult wing shape, a function associated with the FERM protein Expanded and independent of Su(dx). As both Su(dx) and Expanded regulate trafficking, we propose that a conserved role of ZO proteins is to coordinate receptor trafficking and signaling with junctional organization.

  18. The urokinase receptor and its structural homologue C4.4A in human cancer

    DEFF Research Database (Denmark)

    Jacobsen, B; Ploug, M

    2008-01-01

    of C4.4A remains elusive. Nonetheless, both uPAR and C4.4A have been implicated in human pathologies such as wound healing and cancer. A large body of experimental evidence thus demonstrates that high levels of uPAR in resected tumour tissue as well as in plasma are associated with poor prognosis...... for therapy and for non-invasive bioimaging....

  19. Lgr5 homologues associate with Wnt receptors and mediate R-spondin signalling

    NARCIS (Netherlands)

    de Lau, Wim; Barker, Nick; Low, Teck Y.; Koo, Bon-Kyoung; Li, Vivian S. W.; Teunissen, Hans; Kujala, Pekka; Haegebarth, Andrea; Peters, Peter J.; van de Wetering, Marc; Stange, Daniel E.; van Es, Johan E.; Guardavaccaro, Daniele; Schasfoort, Richard B. M.; Mohri, Yasuaki; Nishimori, Katsuhiko; Mohammed, Shabaz; Heck, Albert J. R.; Clevers, Hans

    2011-01-01

    The adult stem cell marker Lgr5 and its relative Lgr4 are often co-expressed in Wnt-driven proliferative compartments. We find that conditional deletion of both genes in the mouse gut impairs Wnt target gene expression and results in the rapid demise of intestinal crypts, thus phenocopying Wnt pathw

  20. Separation of bacteriochlorophyll homologues from green photosynthetic sulfur bacteria by reversed-phase HPLC.

    Science.gov (United States)

    Borrego, C M; Garcia-Gil, L J

    1994-07-01

    A reversed-phase High Performance Liquid Cromatography (HPLC) method has been developed to accurately separate bacteriochlorophyllsc, d ande homologues in a reasonably short run time of 60 minutes. By using this method, two well-defined groups of bacteriochlorophyll homologue peaks can be discriminated. The first one consists of 4 peaks (min 24 to 30), which corresponds to the four main farnesyl homologues. The second peak subset is formed by a cluster of up to 10 minor peaks (min 33 to 40). These peaks can be related with series of several alcohol esters of the different chlorosome chlorophylls. The number of homologues was, however, quite variable depending on both, the bacteriochlorophyll and the bacterial species. The method hereby described, also provides a good separation of other photosynthetic pigments, either bacterial (Bacteriochlorophylla, chlorobactene, isorenieratene and okenone) or algal ones (Chlorophylla, Pheophytina and β-carotene). A preliminary screening of the homologue composition of several green photosynthetic bacterial species and isolates, has revealed different relative quantitative patterns. These differences seem to be related to physiological aspects rather than to taxonomic ones. The application of the method to the study of natural populations avoids the typical drawbacks on the pigment identification of overlapping eukaryotic and prokaryotic phototrophic microorganisms, giving further information about their physiological status.

  1. Rabbit neutrophil chemotactic protein (NCP) activates both CXCR1 and CXCR2 and is the functional homologue for human CXCL6.

    Science.gov (United States)

    Catusse, Julie; Struyf, Sofie; Wuyts, Anja; Weyler, Myke; Loos, Tamara; Gijsbers, Klara; Gouwy, Mieke; Proost, Paul; Van Damme, Jo

    2004-11-15

    Neutrophil chemotactic protein (NCP) is a rabbit CXC chemokine with activating and chemotactic properties on neutrophilic granulocytes. Although its selective activity on neutrophils is demonstrated, its interactions with specific chemokine receptors are not defined. For further functional characterization, NCP was chemically synthesized and was found to be equipotent as natural NCP in neutrophil chemotaxis. To identify its human homologue, we separately expressed two potential rabbit NCP receptors (CXCR1 and CXCR2) in Jurkat cells. Pure synthetic NCP was equally efficient to promote chemotaxis through either rabbit CXCR1 or CXCR2. Moreover, chemotaxis assays on rabbit CXCR1 and CXCR2 transfectants showed that NCP uses the same receptors as interleukin-8 (IL-8), a major rabbit CXC chemokine, but not rabbit GROalpha, which only recognized CXCR2. In addition, specific inhibitors for CXCR1 or CXCR2 reduced rabbit neutrophil chemotaxis induced by NCP and rabbit IL-8. Furthermore, NCP and the structurally related human CXCR1/CXCR2 agonist CXCL6/GCP-2 (granulocyte chemotactic protein-2) cross-desensitized each other in intracellular calcium release assays on human neutrophils, further indicating that both chemokines share the same receptors. The inflammatory role of NCP was also evidenced by its potent granulocytosis inducing capacity in rabbits upon systemic administration. This study provides in vitro and in vivo evidences that NCP is the functional rabbit homologue for human CXCL6/GCP-2 rather than the most related CXCR2 agonist CXCL5/ENA-78 (epithelial cell-derived neutrophil activating peptide-78). It is concluded that the rabbit is a better model to study human neutrophil activation compared to mice, which lack CXCL8/IL-8.

  2. Pharmacological characterization of homobaclofen on wild type and mutant GABA(B)1b receptors coexpressed with the GABA(B)2 receptor

    DEFF Research Database (Denmark)

    Jensen, Anders A.; Madsen, Bo E.; Krogsgaard-Larsen, P

    2001-01-01

    Homobaclofen (5-amino-3-(4-chlorophenyl) pentanoic acid) is a homologue of the classical GABA(B) receptor agonist baclofen. In a recent study, the two enantiomers of this compound were tested in a GABA(B) receptor selective [3H]gamma-aminobutyric acid ([3H]GABA) binding assay using rat brain...

  3. Solid-Phase Synthesis of Amine/Carboxyl Substituted Prolines and Proline Homologues: Scope and Limitations.

    Science.gov (United States)

    Zhou, Ziniu; Scott, William L; O'Donnell, Martin J

    2016-03-15

    A solid-phase procedure is used to synthesize racemic peptidomimetics based on the fundamental peptide unit. The peptidomimetics are constructed around proline or proline homologues variably substituted at the amine and carbonyl sites. The procedure expands the diversity of substituted peptidomimetic molecules available to the Distributed Drug Discovery (D3) project. Using a BAL-based solid-phase synthetic sequence the proline or proline homologue subunit is both constructed and incorporated into the peptidomimetic by an α-alkylation, hydrolysis and intramolecular cyclization sequence. Further transformations on solid-phase provide access to a variety of piperazine derivatives representing a class of molecules known to exhibit central nervous system activity. The procedure works well with proline cores, but with larger six- and seven-membered ring homologues the nature of the carboxylic acid acylating the cyclic amine can lead to side reactions and result in poor overall yields.

  4. Peptidoglycan inducible expression of a serine proteinase homologue from kuruma shrimp (Marsupenaeus japonicus).

    Science.gov (United States)

    Rattanachai, Achara; Hirono, Ikuo; Ohira, Tsuyoshi; Takahashi, Yukinori; Aoki, Takashi

    2005-01-01

    A cDNA encoding a serine proteinase homologue of kuruma shrimp (Marsupenaeus japonicus) was cloned. The 1257 bp cDNA encodes a 339 amino acid putative peptide, with a signal sequence of 16 amino acid residues. The deduced amino acid sequence is 42-67% similar to the immune-related serine proteinases and serine proteinase homologues of arthropods. It contains catalytic triad residues in the putative catalytic domain except for one substitution of Ser by a Gly residue. The six cysteine residues that form three disulphide bridges in most serine proteinases were conserved. The M. japonicus serine proteinase homologue was mainly expressed in haemocytes, in which expression dramatically increased after 3 days feeding with peptidoglycan at 0.2 mg kg(-1) shrimp body weight per day.

  5. Expression pattern of INNER NO OUTER homologue in Nymphaea (water lily family, Nymphaeaceae).

    Science.gov (United States)

    Yamada, Toshihiro; Ito, Motomi; Kato, Masahiro

    2003-10-01

    Two homologues of INNER NO OUTER ( INO) in Nymphaea alba and N. colorata (Nymphaeaceae) were isolated and the expression pattern of the N. alba INO homologue NaINO was examined by in situ hybridization. The INO homologues obtained have a portion similar to INO in the predicted amino acid sequences between the conserved zinc finger-like and YABBY domains. In an in situ hybridization analysis, NaINO is expressed in the outer epidermis of the outer integument, inner integument, and the tip of the nucellus. The pattern observed in the outer integument is very similar to that of Arabidopsis thaliana, while the expression in the inner integument and nucellus is not observed in A. thaliana.

  6. Identification and Characterisation of the Murine Homologue of the Gene Responsible for Cystinosis, Ctns

    Directory of Open Access Journals (Sweden)

    Poras Isabelle

    2000-12-01

    Full Text Available Abstract Background Cystinosis is an autosomal recessive disorder characterised by an intralysosomal accumulation of cystine, and affected individuals progress to end-stage renal failure before the age of ten. The causative gene, CTNS, was cloned in 1998 and the encoded protein, cystinosin, was predicted to be a lysosomal membrane protein. Results We have cloned the murine homologue of CTNS, Ctns, and the encoded amino acid sequence is 92.6% similar to cystinosin. We localised Ctns to mouse chromosome 11 in a region syntenic to human chromosome 17 containing CTNS. Ctns is widely expressed in all tissues tested with the exception of skeletal muscle, in contrast to CTNS. Conclusions We have isolated, characterised and localised Ctns, the murine homologue of CTNS underlying cystinosis. Furthermore, our work has brought to light the existence of a differential pattern of expression between the human and murine homologues, providing critical information for the generation of a mouse model for cystinosis.

  7. CRIP homologues maintain apical cytoskeleton to regulate tubule size in C. elegans.

    Science.gov (United States)

    Tong, Xiangyan; Buechner, Matthew

    2008-05-01

    Maintenance of the shape and diameter of biological tubules is a critical task in the development and physiology of all metazoan organisms. We have cloned the exc-9 gene of Caenorhabditis elegans, which regulates the diameter of the single-cell excretory canal tubules. exc-9 encodes a homologue of the highly expressed mammalian intestinal LIM-domain protein CRIP, whose function has not previously been determined. A second well-conserved CRIP homologue functions in multiple valves of C. elegans. EXC-9 shows genetic interactions with other EXC proteins, including the EXC-5 guanine exchange factor that regulates CDC-42 activity. EXC-9 and its nematode homologue act in polarized epithelial cells that must maintain great flexibility at their apical surface; our results suggest that CRIPs function to maintain cytoskeletal flexibility at the apical surface.

  8. CRIP Homologues Maintain Apical Cytoskeleton to Regulate Tubule Size in C. elegans

    OpenAIRE

    Tong, Xiangyan; Buechner, Matthew

    2008-01-01

    Maintenance of the shape and diameter of biological tubules is a critical task in the development and physiology of all metazoan organisms. We have cloned the exc-9 gene of C. elegans, which regulates the diameter of the single-cell excretory canal tubules. exc-9 encodes a homologue of the highly expressed mammalian intestinal LIM-domain protein CRIP, whose function has not previously been determined. A second well-conserved CRIP homologue functions in multiple valves of C. elegans. EXC-9 sho...

  9. Identification and cloning of a sequence homologue of dopamine β-hydroxylase

    NARCIS (Netherlands)

    Chambers, Kaylene J.; Tonkin, Leath A.; Chang, Edwin; Shelton, Dawne N.; Linskens, Maarten H.; Funk, Walter D.

    1998-01-01

    We have identified and cloned a cDNA encoding a new member of the monooxygenase family of enzymes. This novel enzyme, which we call MOX (monooxygenase X; unknown substrate) is a clear sequence homologue of the enzyme dopamine β-hydroxylase (DBH). MOX maintains many of the structural features of DBH,

  10. Structure of HLA-A*1101 in complex with a hepatitis B peptide homologue

    DEFF Research Database (Denmark)

    Blicher, Thomas; Kastrup, Jette Sandholm; Pedersen, Lars Østergaard

    2006-01-01

    A high-resolution structure of the human MHC-I molecule HLA-A*1101 is presented in which it forms a complex with a sequence homologue of a peptide that occurs naturally in hepatitis B virus DNA polymerase. The sequence of the bound peptide is AIMPARFYPK, while that of the corresponding natural...

  11. The actin homologue MreB organizes the bacterial cell membrane

    NARCIS (Netherlands)

    Strahl, H.; Burmann, F.; Hamoen, L.W.

    2014-01-01

    The eukaryotic cortical actin cytoskeleton creates specific lipid domains, including lipid rafts, which determine the distribution of many membrane proteins. Here we show that the bacterial actin homologue MreB displays a comparable activity. MreB forms membrane-associated filaments that coordinate

  12. Identification of Plant Homologues of Dual Specificity Yak1-Related Kinases

    Directory of Open Access Journals (Sweden)

    Pavel Karpov

    2014-01-01

    Full Text Available Currently, Dual Specificity YAK1-Related Kinases (MNB/DYRK were found in slime molds, protista, fungi, and animals, but the existence of plant homologues is still unclear. In the present study, we have identified 14 potential plant homologues with the previously unknown functions, based on the strong sequence similarity. The results of bioinformatics analysis revealed their correspondence to DYRK1A, DYRK1B, DYRK3, and DYRK4. For two plant homologues of animal DYRK1A from Physcomitrella patens and Arabidopsis thaliana spatial structures of catalytic domains were predicted, as well as their complexes with ADP and selective inhibitor d15. Comparative analysis of 3D-structures of the human DYRK1A and plant homologues, their complexes with the specific inhibitors, and results of molecular dynamics confirm their structural and functional similarity with high probability. Preliminary data indicate the presence of potential MNB/DYRK specific phosphorylation sites in such proteins associated with plant cytoskeleton as plant microtubule-associated proteins WVD2 and WDL1, and FH5 and SCAR2 involved in the organization and polarity of the actin cytoskeleton and some kinesin-like microtubule motor proteins.

  13. Congenital sideroblastic anemia due to mutations in the mitochondrial HSP70 homologue HSPA9

    DEFF Research Database (Denmark)

    Schmitz-Abe, Klaus; Ciesielski, Szymon J; Schmidt, Paul J

    2015-01-01

    The congenital sideroblastic anemias (CSAs) are relatively uncommon diseases, characterized by defects in mitochondrial heme synthesis, iron-sulfur cluster (Fe-S) biogenesis, or protein synthesis. Here we demonstrate that mutations in HSPA9, a mitochondrial HSP70 homologue located in the 5q...

  14. The Retention Behaviors of Benzene and Its Alkyl Homologues in Microemulsion Electrokinetic Chromatography

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The retention behaviors of benzene and its alkyl homologues in microemulsion electrokinetic chromatography were investigated in both anionic and cationic surfactant MEEKC systems. The effects of the composition of microemulsion on retention time and selectivity were studied. A good linear relationship was obtained between log k' and the carbon number of alkyl chain.

  15. Arabidopsis homologues of the autophagy protein Atg8 are a novel family of microtubule binding proteins

    NARCIS (Netherlands)

    Ketelaar, T.; Voss, C.; Dimmock, S.A.; Thumm, M.; Hussey, P.J.

    2004-01-01

    Autophagy is the non-selective transport of proteins and superfluous organelles destined for degradation to the vacuole in fungae, or the lysosome in animal cells. Some of the genes encoding components of the autophagy pathway are conserved in plants, and here we show that Arabidopsis homologues of

  16. Characterization of Fetal Antigen 1/Delta-Like 1 Homologue Expressing Cells in the Rat Nigrostriatal System

    DEFF Research Database (Denmark)

    Liechti, Rémy; Ducray, Angélique D; Jensen, Pia;

    2015-01-01

    Fetal antigen 1/delta-like 1 homologue (FA1/dlk1) belongs to the epidermal growth factor superfamily and is considered to be a non-canonical ligand for the Notch receptor. Interactions between Notch and its ligands are crucial for the development of various tissues. Moreover, FA1/dlk1 has been su...... adult rats. FA1/dlk1-ir cells were predominantly distributed in the substantia nigra (SN) pars compacta (SNc) and in the ventral tegmental area. Interestingly, the expression of FA1/dlk1 significantly increased in tyrosine hydroxylase (TH)-ir cells during early postnatal development. Co......-localization and tracing studies demonstrated that FA1/dlk1-ir cells in the SNc were nigrostriatal dopaminergic neurons, and unilateral 6-OHDA lesions resulted in loss of both FA1/dlk1-ir and TH-ir cells in the SNc. Surprisingly, increased numbers of FA1/dlk1-ir cells (by 70%) were detected in dopamine-depleted striata...... as compared to unlesioned controls. The higher number of FA1/dlk1-ir cells was likely not due to neurogenesis as colocalization studies for proliferation markers were negative. This suggests that FA1/dlk1 was up-regulated in intrinsic cells in response to the 6-OHDA-mediated loss of FA1/dlk1-expressing SNc...

  17. A Study of the Evolution of the Close Binaries Cyg X-3, IC 10 X-1, NGC 300 X-1, SS 433, and M33 X-7 Using the "Scenario Machine"

    CERN Document Server

    Bogomazov, A I

    2016-01-01

    Evolutionary tracks for the X-ray binaries Cyg X-3, IC 10 X-1, NGC 300 X-1, SS 433, and M33 X-7 are computed using the Scenario Machine code. The compact objects in IC 10 X-1, NGC 300 X-1, and M33 X-7 are the most massive stellar mass black hole candidates. Cyg X-3, IC 10 X-1, and NGC 300 X-1 are the only currently known Wolf-Rayet stars with degenerate companions. SS 433 is the only known superaccretor in the Milky Way. Therefore, the stars studied provide excellent laboratories for testing scenarios for the evolution of binaries under extreme conditions. The classical evolutionary scenario is consistent with modern observational data. During the evolution of these binaries, hypernova explosions accompanied by the collapse of stellar cores with large angular momenta can occur, leading to long gamma-ray bursts. At the end of their evolution, Cyg X-3, IC 10 X-1, NGC 300 X-1, and SS 433 may form binary relativistic objects, which will subsequently merge due to the radiation of gravitational waves. The gravitati...

  18. Rabbit muscle creatine phosphokinase. CDNA cloning, primary structure and detection of human homologues.

    Science.gov (United States)

    Putney, S; Herlihy, W; Royal, N; Pang, H; Aposhian, H V; Pickering, L; Belagaje, R; Biemann, K; Page, D; Kuby, S

    1984-12-10

    A cDNA library was constructed from rabbit muscle poly(A) RNA. Limited amino acid sequence information was obtained on rabbit muscle creatine phosphokinase and this was the basis for design and synthesis of two oligonucleotide probes complementary to a creatine kinase cDNA sequence which encodes a pentapeptide. Colony hybridizations with the probes and subsequent steps led to isolation of two clones, whose cDNA segments partially overlap and which together encode the entire protein. The primary structure was established from the sequence of two cDNA clones and from independently determined sequences of scattered portions of the polypeptide. The reactive cysteine has been located to position 282 within the 380 amino acid polypeptide. The rabbit cDNA hybridizes to digests of human chromosomal DNA. This reveals a restriction fragment length polymorphism associated with the human homologue(s) which hybridizes to the rabbit cDNA.

  19. Natural replacement of vertically inherited lux-rib genes of Photobacterium aquimaris by horizontally acquired homologues.

    Science.gov (United States)

    Urbanczyk, Henryk; Furukawa, Takashi; Yamamoto, Yuki; Dunlap, Paul V

    2012-08-01

    We report here the first instance of a complete replacement of vertically inherited luminescence genes by horizontally acquired homologues. Different strains of Photobacterium aquimaris contain homologues of the lux-rib genes that have a different evolutionary history. Strain BS1 from the Black Sea contains a vertically inherited lux-rib operon, which presumably arose in the ancestor of this species, whereas the type strain NBRC 104633(T) , from Sagami Bay, lacks the vertically inherited lux-rib operon and instead carries a complete and functional lux-rib operon acquired horizontally from a bacterium related to Photobacterium mandapamensis. The results indicate that the horizontal acquisition of the lux genes expanded the pan-genome of P. aquimaris, but it did not influence the phylogenetic divergence of this species.

  20. Formation of Benzyl Carbanion in Collision-Induced Dissociation of Deprotonated Phenylalanine Homologues.

    Science.gov (United States)

    Sekimoto, Kanako; Matsuda, Natsuki; Takayama, Mitsuo

    2014-01-01

    The fragmentation behavior of deprotonated L-phenylalanine (Phe) and its homologues including L-homophenylalanine (HPA) and L-phenylglycine (PG) was investigated using collision-induced dissociation mass spectrometry coupled with a negative ion atmospheric pressure corona discharge ionization (APCDI) technique. The deprotonated molecules [M-H](-) fragmented to lose unique neutral species, e.g., the loss of NH3, CO2, toluene and iminoglycine for [Phe-H](-); styrene and ethenamine/CO2 for [HPA-H](-); and CO2 for [PG-H](-). All of the fragmentations observed are attributable to the formation of intermediates and/or product ions which include benzyl carbanions having resonance-stabilized structures. The carbanions are formed via proton rearrangement through a transition state or via a simple dissociation reaction. These results suggest that the principal factor governing the fragmentation behavior of deprotonated Phe homologues is the stability of the intermediate and/or product ion structures.

  1. C21orf57 is a human homologue of bacterial YbeY proteins.

    Science.gov (United States)

    Ghosal, Anubrata; Köhrer, Caroline; Babu, Vignesh M P; Yamanaka, Kinrin; Davies, Bryan W; Jacob, Asha I; Ferullo, Daniel J; Gruber, Charley C; Vercruysse, Maarten; Walker, Graham C

    2017-03-11

    The product of the human C21orf57 (huYBEY) gene is predicted to be a homologue of the highly conserved YbeY proteins found in nearly all bacteria. We show that, like its bacterial and chloroplast counterparts, the HuYbeY protein is an RNase and that it retains sufficient function in common with bacterial YbeY proteins to partially suppress numerous aspects of the complex phenotype of an Escherichia coli ΔybeY mutant. Expression of HuYbeY in Saccharomyces cerevisiae, which lacks a YbeY homologue, results in a severe growth phenotype. This observation suggests that the function of HuYbeY in human cells is likely regulated through specific interactions with partner proteins similarly to the way YbeY is regulated in bacteria.

  2. [Homologue pairing: initiation sites and effects on crossing over and chromosome disjunction in Drosophila melanogaster].

    Science.gov (United States)

    Chubykin, V L

    1996-01-01

    The role of homologue pairing and chromocentral association of chromosomes in recombination and segregation during cell division is discussed. Peculiarities of mitotic and meiotic chromosome pairing in Drosophila males and females are considered. On the basis of our own and published data, the presence and localization of sites of homologue pairing initiation in euchromatin are substantiated. The effects of transfer of initiation sites along a chromosome (exemplified by inversions) on chromosome pairing (asynapsis), crossing over (intrachromosomal, interchromosomal, and centromeric effects), and segregation are discussed. To record the effects of pairing sites on crossing over, a method of comparing crossing-over frequencies in an inverted region with those in a region of the same size and position with regard to the centromere on cytological maps was proposed. Chromosomes orient toward opposite division poles during paracentromeric heterochromatin pairing. This occurs after successful euchromatin pairing, during which the chromocentral circular structure is reorganized. If heterochromatin pairing is disrupted because of structural or locus mutations, nonexchange bivalents segregate randomly. In this case, chromosome coordination may occur due to proximal chiasmata or chromocentral associations between homologues.

  3. Homologue of mammalian apolipoprotein A-Ⅱ in non-mammalian vertebrates

    Institute of Scientific and Technical Information of China (English)

    Malay Choudhury; Shoji Yamada; Masaharu Komatsu; Hideki Kishimura; Seiichi Ando

    2009-01-01

    Although apolipoprotein with molecular weight 14 kDa (apo-14 kDa) is associated with fish plasma highdensity lipoproteins(HDLs),it remains to be determined whether apo-14 kDa is the homologue of mammalian apoA-Ⅱ.We have obtained the full cDNA sequences that encode Japanese eel and rainbow trout apo-14 kDa.Homologues of Japanese eel apo-14 kDa sequence could be found in 14 fish species deposited in the DDBJ/EMBL/GenBank or TGI database.Fish apo14 kDa lacks propeptide and contains more internal repeats than mammalian apoA-Ⅱ.Nevertheless,phylogenetic analysis allowed fish apo-14 kDa to be the homologue of mammalian apoA-Ⅱ.In addition,in silico cloning of the TGI,Ensembl,or NCBI database revealed apoA-Ⅱs in dog,chicken,green anole lizard,and African clawed frog whose sequences had not so far been available,suggesting both apoA-Ⅰ and apoA-Ⅱas fundamental constituents of vertebrate HDLs.

  4. Osmotic stress-dependent serine phosphorylation of the histidine kinase homologue DokA

    Directory of Open Access Journals (Sweden)

    Oehme Felix

    2001-03-01

    Full Text Available Abstract Background Two-component systems consisting of histidine kinases and their corresponding receivers are widespread in bacterial signal transduction. In the past few years, genes coding for homologues of two-component systems were also discovered in eukaryotic organisms. DokA, a homologue of bacterial histidine kinases, is an element of the osmoregulatory pathway in the amoeba Dictyostelium. The work described here addresses the question whether DokA is phosphorylated in vivo in response to osmotic stress. Results We have endogenously overexpressed individual domains of DokA to investigate post-translational modification of the protein in response to osmotic shock in vivo. Dictyostelium cells were labeled with [32P]-orthophosphate, exposed to osmotic stress and DokA fragments were subsequently isolated by immunoprecipitation. Thus, a stress-dependent phosphorylation could be demonstrated, with the site of phosphorylation being located in the kinase domain. We demonstrate biochemically that the phosphorylated amino acid is serine, and by mutational analysis that the phosphorylation reaction is not due to an autophosphorylation of DokA. Furthermore, mutation of the conserved histidine did not affect the osmostress-dependent phosphorylation reaction. Conclusions A stimulus-dependent serine phosphorylation of a eukaryotic histidine kinase homologue was demonstrated for the first time in vivo. That implies that DokA, although showing typical structural features of a bacterial two-component system, might be part of a eukaryotic signal transduction pathway that involves serine/threonine kinases.

  5. Arabidopsis thaliana CENTRORADIALIS homologue (ATC) acts systemically to inhibit floral initiation in Arabidopsis.

    Science.gov (United States)

    Huang, Nien-Chen; Jane, Wann-Neng; Chen, Jychian; Yu, Tien-Shin

    2012-10-01

    Floral initiation is orchestrated by systemic floral activators and inhibitors. This remote-control system may integrate environmental cues to modulate floral initiation. Recently, FLOWERING LOCUS T (FT) was found to be a florigen. However, the identity of systemic floral inhibitor or anti-florigen remains to be elucidated. Here we show that Arabidopsis thaliana CENTRORADIALIS homologue (ATC), an Arabidopsis FT homologue, may act in a non-cell autonomous manner to inhibit floral initiation. Analysis of the ATC null mutant revealed that ATC is a short-day-induced floral inhibitor. Cell type-specific expression showed that companion cells and apex that express ATC are sufficient to inhibit floral initiation. Histochemical analysis showed that the promoter activity of ATC was mainly found in vasculature but under the detection limit in apex, a finding that suggests that ATC may move from the vasculature to the apex to influence flowering. Consistent with this notion, Arabidopsis seedling grafting experiments demonstrated that ATC moved over a long distance and that floral inhibition by ATC is graft transmissible. ATC probably antagonizes FT activity, because both ATC and FT interact with FD and affect the same downstream meristem identity genes APETALA1, in an opposite manner. Thus, photoperiodic variations may trigger functionally opposite FT homologues to systemically influence floral initiation.

  6. Obesity-linked homologues TfAP-2 and Twz establish meal frequency in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Michael J Williams

    2014-09-01

    Full Text Available In all animals managing the size of individual meals and frequency of feeding is crucial for metabolic homeostasis. In the current study we demonstrate that the noradrenalin analogue octopamine and the cholecystokinin (CCK homologue Drosulfakinin (Dsk function downstream of TfAP-2 and Tiwaz (Twz to control the number of meals in adult flies. Loss of TfAP-2 or Twz in octopaminergic neurons increased the size of individual meals, while overexpression of TfAP-2 significantly decreased meal size and increased feeding frequency. Of note, our study reveals that TfAP-2 and Twz regulate octopamine signaling to initiate feeding; then octopamine, in a negative feedback loop, induces expression of Dsk to inhibit consummatory behavior. Intriguingly, we found that the mouse TfAP-2 and Twz homologues, AP-2β and Kctd15, co-localize in areas of the brain known to regulate feeding behavior and reward, and a proximity ligation assay (PLA demonstrated that AP-2β and Kctd15 interact directly in a mouse hypothalamus-derived cell line. Finally, we show that in this mouse hypothalamic cell line AP-2β and Kctd15 directly interact with Ube2i, a mouse sumoylation enzyme, and that AP-2β may itself be sumoylated. Our study reveals how two obesity-linked homologues regulate metabolic homeostasis by modulating consummatory behavior.

  7. Achaete-scute complex homologue-1 promotes development of laryngocarcinoma via facilitating the epithelial-mesenchymal transformation.

    Science.gov (United States)

    Ma, Huaci; Du, Xiaodong; Zhang, Shu; Wang, Qiang; Yin, Yong; Qiu, Xiaoxia; Da, Peng; Yue, Huijun; Wu, Hao; Xu, Fenglei

    2017-06-01

    Laryngeal cancer is one of the most common fatal cancers among head and neck carcinomas, whose mechanism, however, remains unclear. The proneural basic-helix-loop-helix protein achaete-scute complex homologue-1, a member of the basic helix-loop-helix family, plays a very important role in many cancers. This study aims to explore the clinical value and mechanism of achaete-scute complex homologue-1 in laryngeal cancer. Methods including Cell Counting Kit-8, flow cytometry, Transwell invasion assays, and scratch assay were adopted to further explore the bio-function of achaete-scute complex homologue-1, whose expression was examined in fresh and paraffin chip of laryngeal carcinoma tissues by means of western blot and immunohistochemistry, after the interference of achaete-scute complex homologue-1; achaete-scute complex homologue-1, an overexpression in laryngeal carcinoma whose carcinogenicity potential was confirmed via western blot, was correlative with T classification (p = 0.002), histological differentiation (p = 0.000), lymph node metastasis (p = 0.000), and poor survival (p = 0.000). Multivariate analysis shows that achaete-scute complex homologue-1 overexpression is an independent prognostic factor unfavorable to laryngeal carcinoma patients (p = 0.000). Moreover, knocking down achaete-scute complex homologue-1 expression could significantly suppress the proliferation, migration, and invasion of laryngeal carcinoma cell in vitro and disorder epithelial-mesenchymal transformation-associated protein expression. Achaete-scute complex homologue-1 plays an important role in the genesis and progression of laryngeal carcinoma and may act as a potential biomarker for therapeutic target and prognostic prediction.

  8. Functional Characterization of Aspergillus nidulans ypkA, a Homologue of the Mammalian Kinase SGK

    Science.gov (United States)

    Colabardini, Ana Cristina; Brown, Neil Andrew; Savoldi, Marcela; Goldman, Maria Helena S.; Goldman, Gustavo Henrique

    2013-01-01

    The serum- and glucocorticoid-regulated protein kinase (SGK) is an AGC kinase involved in signal cascades regulated by glucocorticoid hormones and serum in mammals. The Saccharomyces cerevisiae ypk1 and ypk2 genes were identified as SGK homologues and Ypk1 was shown to regulate the balance of sphingolipids between the inner and outer plasma membrane. This investigation characterized the Aspergillus nidulans YPK1 homologue, YpkA, representing the first filamentous fungal YPK1 homologue. Two conditional mutant strains were constructed by replacing the endogenous ypk1 promoter with two different regulatable promoters, alcA (from the alcohol dehydrogenase gene) and niiA (from the nitrate reductase gene). Both constructs confirmed that ypkA was an essential gene in A. nidulans. Repression of ypkA caused decreased radial growth, a delay in conidial germination, deficient polar axis establishment, intense branching during late stages of growth, a lack of asexual spores, and a terminal phenotype. Membrane lipid polarization, endocytosis, eisosomes and vacuolar distribution were also affected by ypkA repression, suggesting that YpkA plays a role in hyphal morphogenesis via coordinating the delivery of cell membrane and wall constituents to the hyphal apex. The A. nidulans Pkh1 homologue pkhA was also shown to be an essential gene, and preliminary genetic analysis suggested that the ypkA gene is not directly downstream of pkhA or epistatic to pkhA, rather, ypkA and pkhA are genetically independent or in parallel. BarA is a homologue of the yeast Lag1 acyl-CoA-dependent ceramide synthase, which catalyzes the condensation of phytosphingosine with a fatty acyl-CoA to form phytoceramide. When barA was absent, ypkA repression was lethal to the cell. Therefore, there appears to be a genetic interaction between ypkA, barA, and the sphingolipid synthesis. Transcriptional profiling of ypkA overexpression and down-regulation revealed several putative YpkA targets associated with the

  9. Functional characterization of Aspergillus nidulans ypkA, a homologue of the mammalian kinase SGK.

    Science.gov (United States)

    Colabardini, Ana Cristina; Brown, Neil Andrew; Savoldi, Marcela; Goldman, Maria Helena S; Goldman, Gustavo Henrique

    2013-01-01

    The serum- and glucocorticoid-regulated protein kinase (SGK) is an AGC kinase involved in signal cascades regulated by glucocorticoid hormones and serum in mammals. The Saccharomyces cerevisiae ypk1 and ypk2 genes were identified as SGK homologues and Ypk1 was shown to regulate the balance of sphingolipids between the inner and outer plasma membrane. This investigation characterized the Aspergillus nidulans YPK1 homologue, YpkA, representing the first filamentous fungal YPK1 homologue. Two conditional mutant strains were constructed by replacing the endogenous ypk1 promoter with two different regulatable promoters, alcA (from the alcohol dehydrogenase gene) and niiA (from the nitrate reductase gene). Both constructs confirmed that ypkA was an essential gene in A. nidulans. Repression of ypkA caused decreased radial growth, a delay in conidial germination, deficient polar axis establishment, intense branching during late stages of growth, a lack of asexual spores, and a terminal phenotype. Membrane lipid polarization, endocytosis, eisosomes and vacuolar distribution were also affected by ypkA repression, suggesting that YpkA plays a role in hyphal morphogenesis via coordinating the delivery of cell membrane and wall constituents to the hyphal apex. The A. nidulans Pkh1 homologue pkhA was also shown to be an essential gene, and preliminary genetic analysis suggested that the ypkA gene is not directly downstream of pkhA or epistatic to pkhA, rather, ypkA and pkhA are genetically independent or in parallel. BarA is a homologue of the yeast Lag1 acyl-CoA-dependent ceramide synthase, which catalyzes the condensation of phytosphingosine with a fatty acyl-CoA to form phytoceramide. When barA was absent, ypkA repression was lethal to the cell. Therefore, there appears to be a genetic interaction between ypkA, barA, and the sphingolipid synthesis. Transcriptional profiling of ypkA overexpression and down-regulation revealed several putative YpkA targets associated with the

  10. Functional characterization of Aspergillus nidulans ypkA, a homologue of the mammalian kinase SGK.

    Directory of Open Access Journals (Sweden)

    Ana Cristina Colabardini

    Full Text Available The serum- and glucocorticoid-regulated protein kinase (SGK is an AGC kinase involved in signal cascades regulated by glucocorticoid hormones and serum in mammals. The Saccharomyces cerevisiae ypk1 and ypk2 genes were identified as SGK homologues and Ypk1 was shown to regulate the balance of sphingolipids between the inner and outer plasma membrane. This investigation characterized the Aspergillus nidulans YPK1 homologue, YpkA, representing the first filamentous fungal YPK1 homologue. Two conditional mutant strains were constructed by replacing the endogenous ypk1 promoter with two different regulatable promoters, alcA (from the alcohol dehydrogenase gene and niiA (from the nitrate reductase gene. Both constructs confirmed that ypkA was an essential gene in A. nidulans. Repression of ypkA caused decreased radial growth, a delay in conidial germination, deficient polar axis establishment, intense branching during late stages of growth, a lack of asexual spores, and a terminal phenotype. Membrane lipid polarization, endocytosis, eisosomes and vacuolar distribution were also affected by ypkA repression, suggesting that YpkA plays a role in hyphal morphogenesis via coordinating the delivery of cell membrane and wall constituents to the hyphal apex. The A. nidulans Pkh1 homologue pkhA was also shown to be an essential gene, and preliminary genetic analysis suggested that the ypkA gene is not directly downstream of pkhA or epistatic to pkhA, rather, ypkA and pkhA are genetically independent or in parallel. BarA is a homologue of the yeast Lag1 acyl-CoA-dependent ceramide synthase, which catalyzes the condensation of phytosphingosine with a fatty acyl-CoA to form phytoceramide. When barA was absent, ypkA repression was lethal to the cell. Therefore, there appears to be a genetic interaction between ypkA, barA, and the sphingolipid synthesis. Transcriptional profiling of ypkA overexpression and down-regulation revealed several putative YpkA targets

  11. Importance of MutL homologue MLH1 and MutS homologue MSH2 expression in Turkish patients with sporadic colorectal cancer

    Institute of Scientific and Technical Information of China (English)

    Sibel Erdamar; Esra Ucaryilmaz; Gokhan Demir; Tayfun Karahasanoglu; Gulen Dogusoy; Ahmet Dirican; Suha Goksel

    2007-01-01

    AIM: To assess the incidence of MLH1 (the human MutL homologue) and MSH2 (the human MutS homologue)protein expression in Turkish patients with sporadic colorectal cancers and to compare their survival and clinicopathological features.METHODS: We validated the tissue microarray technology in 77 colorectal carcinomas by analyzing the immunohistochemical expression of proteins involved in two main pathways of colorectal carcinogenesis: p53 protein for loss of heterozygosity tumors; MLH1 and MSH2 proteins for microsatellite instability (MSI).RESULTS: Our analysis showed that 29 (39.2%) had loss of MLH1 expression, 5 (6.8%) had loss of MSH2 expression and 2 cases had loss of expression of both proteins. We found that 60% of MSH2-negative tumors were located in the right side of the colon; all MSH2-negative cases were women. In addition, the loss of MSH2 expression was correlated with low p53 expression. Neither MLH1 nor MSH2 expressions were associated with prognosis, although there seemed a tendency of longer survival (71.7 ± 8.65 mo vs 47.08 ± 5.26 mo) for the patients with MLH1-negative versus MLH1-positive carcinomas. There were not significant differences in overall and recurrence-free survival among MLH1/MSH2-positive and -negative cases.CONCLUSION: Our data supports that Turkish patients with MLH1- and MSH2-defective tumors have some distinct features from each other. Although prognostic importance remains controversial, immunohistochemical analysis of mismatch repair genes may be used as a routine histopathological examination of sporadic colorectal carcinomas.

  12. Health risk equations and risk assessment of airborne benzene homologues exposure to drivers and passengers in taxi cabins.

    Science.gov (United States)

    Chen, Xiaokai; Feng, Lili; Luo, Huilong; Cheng, Heming

    2016-03-01

    Interior air environment and health problems of vehicles have attracted increasing attention, and benzene homologues (BHs) including benzene, toluene, ethylbenzene, xylenes, and styrene are primary hazardous gases in vehicular cabins. The BHs impact on the health of passengers and drivers in 38 taxis is assessed, and health risk equations of in-car BHs to different drivers and passengers are induced. The health risk of in-car BHs for male drivers is the highest among all different receptors and is 1.04, 6.67, and 6.94 times more than ones for female drivers, male passengers, and female passengers, respectively. In-car BHs could not lead to the non-cancer health risk to all passengers and drivers as for the maximal value of non-cancer indices is 0.41 and is less than the unacceptable value (1.00) of non-cancer health risk from USEPA. However, in-car BHs lead to cancer health risk to drivers as for the average value of cancer indices is 1.21E-04 which is 1.21 times more than the unacceptable value (1.00E-04) of cancer health risk from USEPA. Finally, for in-car airborne benzene concentration (X, μg/m(3)) to male drivers, female drivers, male passengers, and female passengers, the cancer health risk equations are Y = 1.48E-06X, Y = 1.42E-06X, Y = 2.22E-07X, and Y = 2.13E-07X, respectively, and the non-cancer health risk equations are Y = 1.70E-03X, Y = 1.63E-03X, Y = 2.55E-04X, and Y = 2.45E-04X, respectively.

  13. Vaccination against Bm86 Homologues in Rabbits Does Not Impair Ixodes ricinus Feeding or Oviposition.

    Directory of Open Access Journals (Sweden)

    Jeroen Coumou

    Full Text Available Human tick-borne diseases that are transmitted by Ixodes ricinus, such as Lyme borreliosis and tick borne encephalitis, are on the rise in Europe. Diminishing I. ricinus populations in nature can reduce tick exposure to humans, and one way to do so is by developing an anti-vector vaccine against tick antigens. Currently, there is only one anti-vector vaccine available against ticks, which is a veterinary vaccine based on the tick antigen Bm86 in the gut of Rhipicephalus microplus. Bm86 vaccine formulations cause a reduction in the number of Rhipicephalus microplus ticks that successfully feed, i.e. lower engorgement weights and a decrease in the number of oviposited eggs. Furthermore, Bm86 vaccines reduce transmission of bovine Babesia spp. Previously two conserved Bm86 homologues in I. ricinus ticks, designated as Ir86-1 and Ir86-2, were described. Here we investigated the effect of a vaccine against recombinant Ir86-1, Ir86-2 or a combination of both on Ixodes ricinus feeding. Recombinant Ixodes ricinus Bm86 homologues were expressed in a Drosophila expression system and rabbits were immunized with rIr86-1, rIr86-2, a combination of both or ovalbumin as a control. Each animal was infested with 50 female adults and 50 male adults Ixodes ricinus and tick mortality, engorgement weights and egg mass were analyzed. Although serum IgG titers against rIr86 proteins were elicited, no effect was found on tick feeding between the rIr86 vaccinated animals and ovalbumin vaccinated animals. We conclude that vaccination against Bm86 homologues in Ixodes ricinus is not an effective approach to control Ixodes ricinus populations, despite the clear effects of Bm86 vaccination against Rhipicephalus microplus.

  14. The TFL1 homologue KSN is a regulator of continuous flowering in rose and strawberry.

    Science.gov (United States)

    Iwata, Hikaru; Gaston, Amèlia; Remay, Arnaud; Thouroude, Tatiana; Jeauffre, Julien; Kawamura, Koji; Oyant, Laurence Hibrand-Saint; Araki, Takashi; Denoyes, Béatrice; Foucher, Fabrice

    2012-01-01

    Flowering is a key event in plant life, and is finely tuned by environmental and endogenous signals to adapt to different environments. In horticulture, continuous flowering (CF) is a popular trait introduced in a wide range of cultivated varieties. It played an essential role in the tremendous success of modern roses and woodland strawberries in gardens. CF genotypes flower during all favourable seasons, whereas once-flowering (OF) genotypes only flower in spring. Here we show that in rose and strawberry continuous flowering is controlled by orthologous genes of the TERMINAL FLOWER 1 (TFL1) family. In rose, six independent pairs of CF/OF mutants differ in the presence of a retrotransposon in the second intron of the TFL1 homologue. Because of an insertion of the retrotransposon, transcription of the gene is blocked in CF roses and the absence of the floral repressor provokes continuous blooming. In OF-climbing mutants, the retrotransposon has recombined to give an allele bearing only the long terminal repeat element, thus restoring a functional allele. In OF roses, seasonal regulation of the TFL1 homologue may explain the seasonal flowering, with low expression in spring to allow the first bloom. In woodland strawberry, Fragaria vesca, a 2-bp deletion in the coding region of the TFL1 homologue introduces a frame shift and is responsible for CF behaviour. A diversity analysis has revealed that this deletion is always associated with the CF phenotype. Our results demonstrate a new role of TFL1 in perennial plants in maintaining vegetative growth and modifying flowering seasonality.

  15. Vaccination against Bm86 Homologues in Rabbits Does Not Impair Ixodes ricinus Feeding or Oviposition

    Science.gov (United States)

    Coumou, Jeroen; Wagemakers, Alex; Trentelman, Jos J.; Nijhof, Ard M.; Hovius, Joppe W.

    2015-01-01

    Human tick-borne diseases that are transmitted by Ixodes ricinus, such as Lyme borreliosis and tick borne encephalitis, are on the rise in Europe. Diminishing I. ricinus populations in nature can reduce tick exposure to humans, and one way to do so is by developing an anti-vector vaccine against tick antigens. Currently, there is only one anti-vector vaccine available against ticks, which is a veterinary vaccine based on the tick antigen Bm86 in the gut of Rhipicephalus microplus. Bm86 vaccine formulations cause a reduction in the number of Rhipicephalus microplus ticks that successfully feed, i.e. lower engorgement weights and a decrease in the number of oviposited eggs. Furthermore, Bm86 vaccines reduce transmission of bovine Babesia spp. Previously two conserved Bm86 homologues in I. ricinus ticks, designated as Ir86-1 and Ir86-2, were described. Here we investigated the effect of a vaccine against recombinant Ir86-1, Ir86-2 or a combination of both on Ixodes ricinus feeding. Recombinant Ixodes ricinus Bm86 homologues were expressed in a Drosophila expression system and rabbits were immunized with rIr86-1, rIr86-2, a combination of both or ovalbumin as a control. Each animal was infested with 50 female adults and 50 male adults Ixodes ricinus and tick mortality, engorgement weights and egg mass were analyzed. Although serum IgG titers against rIr86 proteins were elicited, no effect was found on tick feeding between the rIr86 vaccinated animals and ovalbumin vaccinated animals. We conclude that vaccination against Bm86 homologues in Ixodes ricinus is not an effective approach to control Ixodes ricinus populations, despite the clear effects of Bm86 vaccination against Rhipicephalus microplus. PMID:25919587

  16. Knockdown of the putative Lifeguard homologue CG3814 in neurons of Drosophila melanogaster.

    Science.gov (United States)

    M'Angale, P G; Staveley, B E

    2016-12-19

    Lifeguard is an integral transmembrane protein that modulates FasL-mediated apoptosis by interfering with the activation of caspase 8. It is evolutionarily conserved, with homologues present in plants, nematodes, zebra fish, frog, chicken, mouse, monkey, and human. The Lifeguard homologue in Drosophila, CG3814, contains the Bax inhibitor-1 family motif of unknown function. Downregulation of Lifeguard disrupts cellular homeostasis and disease by sensitizing neurons to FasL-mediated apoptosis. We used bioinformatic analyses to identify CG3814, a putative homologue of Lifeguard, and knocked down CG3814/LFG expression under the control of the Dopa decarboxylase (Ddc-Gal4) transgene in Drosophila melanogaster neurons to investigate whether it possesses neuroprotective activity. Knockdown of CG3814/LFG in Ddc-Gal4-expressing neurons resulted in a shortened lifespan and impaired locomotor ability, phenotypes that are strongly associated with the degeneration and loss of dopaminergic neurons. Lifeguard interacts with anti-apoptotic Bcl-2 proteins and possibly pro-apoptotic proteins to exert its neuroprotective function. The co-expression of Buffy, the sole anti-apoptotic Bcl-2 gene family member in Drosophila, and CG3814/LFG by stable inducible RNA interference, suppresses the shortened lifespan and the premature age-dependent loss in climbing ability. Suppression of CG3814/LFG in the Drosophila eye reduces the number of ommatidia and increases disruption of the ommatidial array. Overexpression of Buffy, along with the knockdown of CG3814/LFG, counteracts the eye phenotypes. Knockdown of CG3814/LFG in Ddc-Gal4-expressing neurons in Drosophila diminishes its neuroprotective ability and results in a shortened lifespan and loss of climbing ability, phenotypes that are improved upon overexpression of the pro-survival Buffy.

  17. Plasmodium falciparum Histone Acetyltransferase, a Yeast GCN5 Homologue Involved in Chromatin Remodeling

    Institute of Scientific and Technical Information of China (English)

    QiFan; LijiaAn; LiwangCui

    2005-01-01

    The yeast transcriptional coactivator GCN5 (yGCN5), a histone acetyltransferase (HAT), is part of large multimeric complexes that are required for chromatin remodeling and transcriptional activation. Like other eukaryotes, the malaria parasite DNA is organized into nucleosomes and the genome encodes components of chromatin-remodeling complexes. Here we show that GCN5 is conserved in Plasmodium species and that the most homologous regions are within the HAT domain and the bromodomain. The Plasmodiumfalclparum GCN5 homologue (PfGCN5) is spliced with three introns, encoding a protein of 1,464 residues. Mapping of the ends of the PfGCN5 transcript suggests that the mRNA is 5.2 to 5.4 kb, consistent with the result from Northern analysis. Using free core histones, we determined that recombinant PfGCN5 proteins have conserved HAT activity with a substrate preference for histone H3. Using substrate-specific antibodies, we determined that both Lys-8 and -14 of H3 were acetylated by the recombinant PfGCN5. In eukaryotes, GCN5 homologues interact with yeast ADA2 homologues and form large multiprotein HAT complexes. We have identified an ADA2 homologue in P. falciparum, PfADA2. Yeast two-hybrid and in vitro binding assays verified the interactions between PfGCN5 and PfADA2, suggesting that they may be associated with each other in vivo. The conserved function of the HAT domain in PfGCN5 was further illustrated with yeast complementation experiments, which showed that the PfGCN5 region corresponding to the full-length yGCN5 could partially complement the yGCN5 deletion mutation. Furthermore, a chimera comprising the PfGCN5 HAT domain fused to the remainder of yeast GCN5 (yGCN5) fully rescued the yGCN5 deletion mutant. These data demonstrate that PfGCN5 is an authentic GCN5 family member and may exist in chromatin-remodeling complexes to regulate gene expression in P. falciparum.

  18. Molecular Cloning of a Novel Bovine Homologue of the Drosophila Tumor Suppressor Gene, Lats

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Pervious studies demonstrate that lats, also known as warts, is a tumor suppressor gene in Drosophila[1,2]. Mutations of lats lead to an increase in cell number and organ size in Drosophila, indicating lats may be involved in organ size control. Furthermore, the high conservation of sequence and tumor suppression function of lats between Drosophila and human suggests that it may be also involved in organ size control of higher animals[3]. So here we isolated the bovine homologue of Drosophila lats. Sequence analysis indicates the bovine LATS1 to be very similar to other lats proteins.

  19. The primary structure of ammodytin L, a myotoxic phospholipase A2 homologue from Vipera ammodytes venom.

    Science.gov (United States)

    Krizaj, I; Bieber, A L; Ritonja, A; Gubensek, F

    1991-12-18

    A new myotoxic phospholipase A2 homologue, having a serine residue in position 49 instead of highly conserved aspartic acid, was found in the venom of Vipera ammodytes. The primary structure revealed additional mutations in the positions important for enzymatic activity. Tyr28 is exchanged for a histidine and Gly33 for asparagine. These changes render earlier-reported weak enzymatic activity unlikely. The role of this rather abundant venom fraction is apparently in myotoxicity, which was confirmed in the muscle-cell culture from neonatal rats. The muscle-cell culture proved to be a good tool to investigate the effects of various myotoxins on muscle cells.

  20. Yeast as a model system for mammalian seven-transmembrane segment receptors

    Energy Technology Data Exchange (ETDEWEB)

    Jeansonne, N.E. [East Carolina Univ. Medical School, Greenville, NC (United States)

    1994-05-01

    Investigators have used the budding yeast Saccharomyces cerevisiae as a model system in which to study the {beta}-adrenergic receptor, the T-cell receptor pathway, initiation of mammalian DNA replication, initiation of mammalian transcription, secretion, the CDC2 kinase system, cell cycle control, and aging, as well as the function of oncogenes. This list continues to growth with the discovery of an immunoglobulin heavy-chain binding homologue in yeast, an Rb binding protein homologue, and a possible yeast arrestin. Yeast is relatively easy to maintain, to grow, and to genetically manipulate. A single gene can be overexpressed, selectively mutated or deleted from its chromosomal location. In this way, the in vivo function of a gene can be studied. It has become reasonable to consider yeast as a model system for studying the seven transmembrane segments (7-TMS) receptor family. Currently, subtypes of the {beta}-adrenergic receptor are being studied in yeast. The receptor and its G{sub {alpha}}-G-protein, trigger the mating pheromone receptor pathway. This provides a powerful assay for determining receptor function. Studies expressing the muscarinic cholinergic receptor in yeast are underway. The yeast pheromone receptor belongs to this receptor family, sharing sequences and secondary structure homology. An effective strategy has been to identify a yeast pathway or process which is homologous to a mammalian system. The pathway is delineated in yeast, identifying other genetic components. Then yeast genes are used to screen for human homologues of these components. The putative human homologues are then expressed in yeast and in mammalian cells to determine function. When this type of {open_quotes}mixing and matching{close_quotes} works, yeast genetics can be a powerful tool. 115 refs.

  1. C-type lectins in immune defense against pathogens: the murine DC-SIGN homologue SIGNR3 confers early protection against Mycobacterium tuberculosis infection.

    Science.gov (United States)

    Tanne, Antoine; Neyrolles, Olivier

    2010-01-01

    Host defense against pathogens involves various receptors expressed in cells of the immune system. Upon pathogen recognition, these proteins mediate a plethora of effector functions, such as the secretion of key protective cytokines and other immune mediators. These receptors include C-type lectins (CTLs), which are increasingly being recognized as major players in the host response to microbes. One particular CTL, DCSIGN/CD209, recognizes conserved sugar motifs in a number of viruses, parasites and bacteria. In particular, we and others have shown that DC-SIGN plays an important part in the recognition by dendritic cells and macrophages of Mycobacterium tuberculosis, the causal agent of tuberculosis in humans. Using the mouse as a model: host for M. tuberculosis, we recently showed that the DC-SIGN homologue SIGNR3 mediates protection against the tubercle bacillus, possibly through secretion of the key cytokines interleukin 6 and tumor necrosis factor. Here, we summarize and discuss these findings and their implications for the design of future studies aiming to improve our understanding of the role of DC-SIGN and other C-type lectins in immunity to mycobacteria and other pathogens.

  2. The plant PTS1 receptor : similarities and differences to its human and yeast counterparts

    NARCIS (Netherlands)

    Wimmer, C; Schmid, M; Veenhuis, M; Gietl, C

    1998-01-01

    Two targeting signals, PTS1 and PTS2, mediate import of proteins into the peroxisomal matrix. We have cloned and sequenced the watermelon (Citrullus vulgaris) cDNA homologue to the PTS1 receptor gene (PEX5). Its gene product, CvPex5p, belongs to the family of tetratricopeptide repeat (TPR) containin

  3. IDENTIFICATION OF HUMAN MURR1, THE HOMOLOGUE OF MOUSE IMPRINTED Murr1 GENE

    Institute of Scientific and Technical Information of China (English)

    Zhang Zhongming; Wang Youdong; Hitomi Yatsuki; Keiichiro Joh; Tsuyoshi Iwasaka; Tsunehiro Mukai

    2006-01-01

    Objective To identify the mRNA sequence, genetic construction, imprinting status, and expression profile of human MURR1 gene, the homologue of mouse imprinted Murr1 gene. Methods The MURR1 mRNA sequence was identified by colony hybridization screening of human cDNA library and the 5'-RACE analyses; Absence of U2AF1-RS1 gene within MURR1 was confirmed by Southern Blotting; Expression profile of MURR1 was examined by Northern Blotting; The imprinting status of MURR1 were revealed by SNP investigation and RT-PCR followed by sequencings and RFLP analyses. Results The full-length mRNA sequence of MURR1 spans 711 bp, transcribed from 3 exons, encodes predicted MURR1 protein of 190 amino acids. The gene was expressed in all the 12 kinds of human adult tissues and 6 kinds of fetal tissues. It showed biallelic expression in all 32 investigated samples including 6 kinds of human fetal tissues and 8 adult brains. Unlike mouse imprinted U2af1-rs1 gene existing in the intron of Murr1, the human U2AF1-RS1 gene was not located in the MURR1 locus. Conclusion Human MURR1 gene is not imprinted and the non-imprinting is possible due to the absence of human homologue of mouse U2af1-rs1 within MURR1 locus.

  4. Pescadillo homologue 1 and Peter Pan function during Xenopus laevis pronephros development.

    Science.gov (United States)

    Tecza, Aleksandra; Bugner, Verena; Kühl, Michael; Kühl, Susanne J

    2011-10-01

    pes1 (pescadillo homologue 1) and ppan (Peter Pan) are multifunctional proteins involved in ribosome biogenesis, cell proliferation, apoptosis, cell migration and regulation of gene expression. Both proteins are required for early neural development in Xenopus laevis, as previously demonstrated. We show that the expression of both genes in the developing pronephros depends on wnt4 and fzd3 (frizzled homologue 3) function. Loss of pes1 or ppan by MO (morpholino oligonucleotide)-based knockdown approaches resulted in strong malformations during pronephric tubule formation. Defects were already notable during specification of pronephric progenitor cells, as shown by lhx1 expression. Moreover, we demonstrated that Xenopus pes1 and ppan interact physically and functionally and that pes1 and ppan can cross-rescue the loss of function phenotype of one another. Interference with rRNA synthesis, however, did not result in a similar early pronephros phenotype. These results demonstrate that pes1 and ppan are required for Xenopus pronephros development and indicate that their function in the pronephros is independent of their role in ribosome biosynthesis.

  5. Protease inhibitor homologues from mamba venoms: facilitation of acetylcholine release and interactions with prejunctional blocking toxins.

    Science.gov (United States)

    Harvey, A L; Karlsson, E

    1982-09-01

    1 Five polypeptides, which were isolated from elapid snake venoms and which are structurally related to protease inhibitors, were tested for action on isolated biventer cervicis nerve-muscle preparations of the chick. 2 Dendrotoxin from the Eastern green mamba (Dendroaspis angusticeps) and toxins K and I from the black mamba (Dendroaspis polylepis polylepis) increased to indirect stimulation without affecting responses to exogenous acetylcholine, carbachol of KCl. 3 The two other protease inhibitor homologues, HHV-II from Ringhals cobra (Hemachatus haemachatus) and NNV-II from Cape cobra (Naja nivea) did not increase responses to nerve stimulation. Trypsin inhibitor from bovine pancreas also had no facilitatory effects on neuromuscular transmission. 4 The facilitatory toxins from mamba venoms interacted with the prejunctional blocking toxins, beta-bungarotoxin, crotoxin and notexin, but not with taipoxin. The blocking effects of beta-bungarotoxin were reduced by pretreatment with the mamba toxins, whereas the blocking actions of crotoxin and notexin were enhanced. 5 The results indicate that protease inhibitor homologues from mamba venoms form a new class of neurotoxin, which acts to increase the release of acetylcholine in response to motor nerve stimulation. 6 From the interaction studies it is concluded that the facilitatory toxins bind to motor nerve terminals at sites related to those occupied by the prejunctional blocking toxins. However, differences in interactions with individual toxins suggest that there must be several related binding sites on the nerve terminals.

  6. Heavy Atom Effect on the First Hyperpolarizabilities of Squaric Acid Homologues Studied by Ab Initio and DFT Methods

    Institute of Scientific and Technical Information of China (English)

    FU Wei-Wei; ZHOU Li-Xin; WAN Hua-Ping

    2004-01-01

    We have calculated the first hyperpolarizabilities of four squaric acid homologue molecules: 3,4-dithiohydroxy-3-cyclobutene-1,2-dione (OSSQ), 3,4-dithiohydroxy-3-cyclobutene-1, 2-dithione (SSSQ), 3,4-dithiohydroxy-3-cyclobutene-1,2-diselenone (SeSSQ) and 3,4-dithiohydroxy- 3-cyclobutene-1,2-ditellurone (TeSSQ). The correlation effect was investigated at the second-order Mφller-Plesset (MP2) perturbation and density functional theory (DFT) levels. The frequency disper- sion and solvent effect were considered to compare the theoretical values with the experimental observations. Based on all of these studies, it is worthy to point out that the heavy atom effect dis- covered for furan homologues is an influence on the first hyperpolarizabilities of squaric acid homologues.

  7. Xenopus BTBD6 and its Drosophila homologue lute are required for neuronal development.

    Science.gov (United States)

    Bury, Frédéric J; Moers, Virginie; Yan, Jiekun; Souopgui, Jacob; Quan, Xiao-Jiang; De Geest, Natalie; Kricha, Sadia; Hassan, Bassem A; Bellefroid, Eric J

    2008-11-01

    BBP proteins constitute a subclass of CUL3 interacting BTB proteins whose in vivo function remains unknown. Here, we show that the Xenopus BBP gene BTBD6 and the single Drosophila homologue of mammalian BBP genes lute are strongly expressed in the developing nervous system. In Xenopus, BTBD6 expression responds positively to proneural and negatively to neurogenic gene overexpression. Knockdown of BTBD6 in Xenopus or loss of Drosophila lute result in embryos with strong defects in late neuronal markers and strongly reduced and disorganized axons while early neural development is unaffected. XBTBD6 knockdown in Xenopus also affects muscle development. Together, these data indicate that BTBD6/lute is required for proper embryogenesis and plays an essential evolutionary conserved role during neuronal development.

  8. Synthesis and Characterization of a New Five and Six Membered Selenoheterocyclic Compounds Homologues of Ebselen

    Directory of Open Access Journals (Sweden)

    Mouslim Messali

    2011-01-01

    Full Text Available The discovery of the antioxidant activity of selenoenzyme glutathione peroxidase (GPx has attracted growing attention in the biochemistry of selenium. Among molecules which mimic the structure of the active site of the enzyme, N-phenyl-1,2-benzisoselenazolin-3-one 1, Ebselen, exhibited useful anti-inflammatory properties. It has been extensively investigated and has undergone clinical trials as an anti-inflammatory agent. Unfortunately, Ebselen exhibits relatively poor catalytic activity, prompting attempts to design more efficacious GPx mimetics that would retain his low toxicity while manifesting improved catalytic properties. In this context, novel 1,2-benzoselenazine and 1,2-benzoselenazols, which are five and six membered homologues of Ebselen were synthesized and characterized. One structure has been proven by single crystal X-ray crystallography.

  9. Molecular investigations of pathogenesis-related Bet v 1 homologues in Passiflora (Passifloraceae).

    Science.gov (United States)

    Finkler, Carla; Giacomet, Carolina; Muschner, Valéria C; Salzano, Francisco M; Freitas, Loreta B

    2005-07-01

    The major birch pollen allergen, Bet v 1, responsible for allergic reactions in many areas of the world, is homologous to a large number of pathogenesis-related proteins (PRs), identified as PR10. As part of a long-range investigation of these types of proteins and of evolution in Passiflora, DNA sequences from eight Bet v 1 homologue isoforms were obtained from five species of this genus in Brazil, and their sequences compared among themselves and with 30 others from 8 different species, classified in different taxonomic units. The objective was a first characterization of these PRs in wild passionflowers, and their use for evolutionary and applied investigations. High interspecific, but low intraspecific variability was observed, as expected from multigenic families subjected to concerted evolution. The relationships obtained both within Passiflora and between it and seven other genera probably best reflect functional similarities than evolutionary history.

  10. Homologue Structure of the SLAC1 Anion Channel for Closing Stomata in Leaves

    Energy Technology Data Exchange (ETDEWEB)

    Y Chen; L Hu; M Punta; R Bruni; B Hillerich; B Kloss; B Rost; J Love; S Siegelbaum; W Hendrickson

    2011-12-31

    The plant SLAC1 anion channel controls turgor pressure in the aperture-defining guard cells of plant stomata, thereby regulating the exchange of water vapour and photosynthetic gases in response to environmental signals such as drought or high levels of carbon dioxide. Here we determine the crystal structure of a bacterial homologue (Haemophilus influenzae) of SLAC1 at 1.20 {angstrom} resolution, and use structure-inspired mutagenesis to analyse the conductance properties of SLAC1 channels. SLAC1 is a symmetrical trimer composed from quasi-symmetrical subunits, each having ten transmembrane helices arranged from helical hairpin pairs to form a central five-helix transmembrane pore that is gated by an extremely conserved phenylalanine residue. Conformational features indicate a mechanism for control of gating by kinase activation, and electrostatic features of the pore coupled with electrophysiological characteristics indicate that selectivity among different anions is largely a function of the energetic cost of ion dehydration.

  11. A Salmonella Typhi homologue of bacteriophage muramidases controls typhoid toxin secretion.

    Science.gov (United States)

    Hodak, Hélène; Galán, Jorge E

    2013-01-01

    Unlike other Salmonella, which can infect a broad range of hosts causing self-limiting infection, Salmonella Typhi is an exclusively human pathogen that causes typhoid fever, a life-threatening systemic disease. Typhoid toxin is a unique virulence factor of Salmonella Typhi, which is expressed when the bacteria are within mammalian cells. Here, we report that an N-acetyl-β-D-muramidase similar to phage endolysins encoded within the same pathogenicity islet as the toxin is required for typhoid toxin secretion. Genetic and functional analysis of TtsA revealed unique amino acids at its predicted peptidoglycan-binding domain that are essential for protein secretion and that distinguishes this protein from other homologues. We propose that TtsA defines a new protein secretion mechanism recently evolved from the machine that mediates phage release.

  12. Isolation of a cotton NADP(H oxidase homologue induced by drought stress

    Directory of Open Access Journals (Sweden)

    NEPOMUCENO ALEXANDRE LIMA

    2000-01-01

    Full Text Available The aim of this study was to identify and isolate genes that are differentially expressed in four selected cotton (Gossypium hirsutum L. genotypes contrasting according to their tolerance to water deficit. The genotypes studied were Siokra L-23, Stoneville 506, CS 50 and T-1521. Physiological, morphological and developmental changes that confer drought tolerance in plants must have a molecular genetic basis. To identify and isolate the genes, the mRNA Differential Display (DD technique was used. Messenger RNAs differentially expressed during water deficit were identified, isolated, cloned and sequenced. The cloned transcript A12B15-5, a NADP(H oxidase homologue, was up regulated only during the water deficit stress and only in Siokra L-23, a drought tolerant genotype. Ribonuclease protection assay confirmed that transcription.

  13. Conservation of Oxidative Protein Stabilization in an Insect Homologue of Parkinsonism-Associated Protein DJ-1

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Jiusheng; Prahlad, Janani; Wilson, Mark A. (UNL)

    2012-08-21

    DJ-1 is a conserved, disease-associated protein that protects against oxidative stress and mitochondrial damage in multiple organisms. Human DJ-1 contains a functionally essential cysteine residue (Cys106) whose oxidation is important for regulating protein function by an unknown mechanism. This residue is well-conserved in other DJ-1 homologues, including two (DJ-1{alpha} and DJ-1{beta}) in Drosophila melanogaster. Because D. melanogaster is a powerful model system for studying DJ-1 function, we have determined the crystal structure and impact of cysteine oxidation on Drosophila DJ-1{beta}. The structure of D. melanogaster DJ-1{beta} is similar to that of human DJ-1, although two important residues in the human protein, Met26 and His126, are not conserved in DJ-1{beta}. His126 in human DJ-1 is substituted with a tyrosine in DJ-1{beta}, and this residue is not able to compose a putative catalytic dyad with Cys106 that was proposed to be important in the human protein. The reactive cysteine in DJ-1 is oxidized readily to the cysteine-sulfinic acid in both flies and humans, and this may regulate the cytoprotective function of the protein. We show that the oxidation of this conserved cysteine residue to its sulfinate form (Cys-SO{sub 2{sup -}}) results in considerable thermal stabilization of both Drosophila DJ-1{beta} and human DJ-1. Therefore, protein stabilization is one potential mechanism by which cysteine oxidation may regulate DJ-1 function in vivo. More generally, most close DJ-1 homologues are likely stabilized by cysteine-sulfinic acid formation but destabilized by further oxidation, suggesting that they are biphasically regulated by oxidative modification.

  14. The RuvA homologues from Mycoplasma genitalium and Mycoplasma pneumoniae exhibit unique functional characteristics.

    Directory of Open Access Journals (Sweden)

    Marcel Sluijter

    Full Text Available The DNA recombination and repair machineries of Mycoplasma genitalium and Mycoplasma pneumoniae differ considerably from those of gram-positive and gram-negative bacteria. Most notably, M. pneumoniae is unable to express a functional RecU Holliday junction (HJ resolvase. In addition, the RuvB homologues from both M. pneumoniae and M. genitalium only exhibit DNA helicase activity but not HJ branch migration activity in vitro. To identify a putative role of the RuvA homologues of these mycoplasmas in DNA recombination, both proteins (RuvA(Mpn and RuvA(Mge, respectively were studied for their ability to bind DNA and to interact with RuvB and RecU. In spite of a high level of sequence conservation between RuvA(Mpn and RuvA(Mge (68.8% identity, substantial differences were found between these proteins in their activities. First, RuvA(Mge was found to preferentially bind to HJs, whereas RuvA(Mpn displayed similar affinities for both HJs and single-stranded DNA. Second, while RuvA(Mpn is able to form two distinct complexes with HJs, RuvA(Mge only produced a single HJ complex. Third, RuvA(Mge stimulated the DNA helicase and ATPase activities of RuvB(Mge, whereas RuvA(Mpn did not augment RuvB activity. Finally, while both RuvA(Mge and RecU(Mge efficiently bind to HJs, they did not compete with each other for HJ binding, but formed stable complexes with HJs over a wide protein concentration range. This interaction, however, resulted in inhibition of the HJ resolution activity of RecU(Mge.

  15. The RuvA homologues from Mycoplasma genitalium and Mycoplasma pneumoniae exhibit unique functional characteristics.

    Science.gov (United States)

    Sluijter, Marcel; Estevão, Silvia; Hoogenboezem, Theo; Hartwig, Nico G; van Rossum, Annemarie M C; Vink, Cornelis

    2012-01-01

    The DNA recombination and repair machineries of Mycoplasma genitalium and Mycoplasma pneumoniae differ considerably from those of gram-positive and gram-negative bacteria. Most notably, M. pneumoniae is unable to express a functional RecU Holliday junction (HJ) resolvase. In addition, the RuvB homologues from both M. pneumoniae and M. genitalium only exhibit DNA helicase activity but not HJ branch migration activity in vitro. To identify a putative role of the RuvA homologues of these mycoplasmas in DNA recombination, both proteins (RuvA(Mpn) and RuvA(Mge), respectively) were studied for their ability to bind DNA and to interact with RuvB and RecU. In spite of a high level of sequence conservation between RuvA(Mpn) and RuvA(Mge) (68.8% identity), substantial differences were found between these proteins in their activities. First, RuvA(Mge) was found to preferentially bind to HJs, whereas RuvA(Mpn) displayed similar affinities for both HJs and single-stranded DNA. Second, while RuvA(Mpn) is able to form two distinct complexes with HJs, RuvA(Mge) only produced a single HJ complex. Third, RuvA(Mge) stimulated the DNA helicase and ATPase activities of RuvB(Mge), whereas RuvA(Mpn) did not augment RuvB activity. Finally, while both RuvA(Mge) and RecU(Mge) efficiently bind to HJs, they did not compete with each other for HJ binding, but formed stable complexes with HJs over a wide protein concentration range. This interaction, however, resulted in inhibition of the HJ resolution activity of RecU(Mge).

  16. Isolation and characterization of AtMLH1, a MutL homologue from Arabidopsis thaliana.

    Science.gov (United States)

    Jean, M; Pelletier, J; Hilpert, M; Belzile, F; Kunze, R

    1999-12-01

    DNA mismatch repair systems play an essential role in the maintenance of genetic information in living organisms and are also implicated in genetic recombination and genome stability. Using degenerate primers, we have cloned the first plant homologue of the E. coli MutL gene, which we have called AtMLH1 for Arabidopsis thaliana MutL-homologue 1. AtMLH1 is present as a single-copy gene in the Arabidopsis genome and is located on the top arm of chromosome 4. Sequence analysis revealed that the product of this gene shows extensive sequence homology with other eukaryotic MLH1 proteins. As mlh1-deficient lines would be useful for studying the biological function of this gene, several populations that had been mutagenized using T-DNA and transposon insertions were screened to identify such mutants. One line that carries a T-DNA insertion in the promoter region of the AtMLH1 gene was isolated. Surprisingly, although the insertion occurred only approximately 80 bp upstream of the putative transcription start site, Northern analyses revealed very low but similar amounts of AtMLH1 transcript in both the wild type and the T-DNA insertion lines. RT-PCR analyses suggest, however, that transcription is initiated further upstream in the insertion line and that the T-DNA may supply this novel initiation site. Finally, no increase in microsatellite instability - a phenotype often associated with mutations in mismatch repair genes - was observed in plants homozygous for this insertion.

  17. Isolation of Crb1, a mouse homologue of Drosophila crumbs, and analysis of its expression pattern in eye and brain.

    NARCIS (Netherlands)

    Hollander, A.I. den; Ghiani, M.; Kok, Y.J.M. de; Wijnholds, J.; Ballabio, A.; Cremers, F.P.M.; Broccoli, V.

    2002-01-01

    Mutations in the human Crumbs homologue 1 (CRB1) gene cause severe retinal dystrophies. CRB1 is homologous to Drosophila Crumbs, a protein essential for establishing and maintaining epithelial polarity. We have isolated the mouse orthologue, Crb1, and analyzed its expression pattern in embryonic and

  18. Predominant recognition of species-specific determinants of the GroES homologues from Mycobacterium leprae and M. tuberculosis

    NARCIS (Netherlands)

    Chua-Intra, B.; Ivanyi, J.; Hills, A.; Thole, J.; Moreno, C.; Vordermeier, H.M.

    1998-01-01

    The Mycobacterium leprae and M. tuberculosis 10000 MW heat-shock protein homologues of GroES have previously been identified as major immunogens for human T cells. We used synthetic peptides to characterize the determinants recognized by murine T cells. The findings suggest that, despite 90% sequenc

  19. GTP analogue inhibits polymerization and GTPase activity of the bacterial protein FtsZ without affecting its eukaryotic homologue tubulin.

    NARCIS (Netherlands)

    Läppchen, T.; Hartog, A.F.; Pinas, V.; Koomen, G.J.; den Blaauwen, T.

    2005-01-01

    The prokaryotic tubulin homologue FtsZ plays a key role in bacterial cell division. Selective inhibitors of the GTP-dependent polymerization of FtsZ are expected to result in a new class of antibacterial agents. One of the challenges is to identify compounds which do not affect the function of tubul

  20. 4-Oxalocrotonate tautomerase, its homologue YwhB, and active vinylpyruvate hydratase : Synthesis and evaluation of 2-fluoro substrate analogues

    NARCIS (Netherlands)

    Johnson, William H; Wang, Susan C; Stanley, Thanuja M; Czerwinski, Robert M; Almrud, Jeffrey J; Poelarends, Gerrit J; Murzin, Alexey G; Whitman, Christian P

    2004-01-01

    A series of 2-fluoro-4-alkene and 2-fluoro-4-alkyne substrate analogues were synthesized and examined as potential inhibitors of three enzymes: 4-oxalocrotonate tautomerase (4-OT) and vinylpyruvate hydratase (VPH) from the catechol meta-fission pathway and a closely related 4-OT homologue found in B

  1. Secretory pathway antagonism by calicivirus homologues of Norwalk virus nonstructural protein p22 is restricted to noroviruses

    Directory of Open Access Journals (Sweden)

    Sharp Tyler M

    2012-09-01

    Full Text Available Abstract Background Our previous report that the Norwalk virus nonstructural protein p22 is an antagonist of the cellular secretory pathway suggests a new aspect of norovirus/host interaction. To explore conservation of function of this highly divergent calicivirus protein, we examined the effects of p22 homologues from four human and two murine noroviruses, and feline calicivirus on the secretory pathway. Findings All human noroviruses examined induced Golgi disruption and inhibited protein secretion, with the genogroup II.4 Houston virus being the most potent antagonist. Genogroup II.6 viruses have a conserved mutation in the mimic of an Endoplasmic Reticulum export signal (MERES motif that is highly conserved in human norovirus homologues of p22 and is critical for secretory pathway antagonism, and these viruses had reduced levels of Golgi disruption and inhibition of protein secretion. p22 homologues from both persistent and nonpersistent strains of murine norovirus induced Golgi disruption, but only mildly inhibited cellular protein secretion. Feline calicivirus p30 did not induce Golgi disruption or inhibit cellular protein secretion. Conclusions These differences confirm a norovirus-specific effect on host cell secretory pathway antagonism by homologues of p22, which may affect viral replication and/or cellular pathogenesis.

  2. Secretory pathway antagonism by calicivirus homologues of Norwalk virus nonstructural protein p22 is restricted to noroviruses.

    Science.gov (United States)

    Sharp, Tyler M; Crawford, Sue E; Ajami, Nadim J; Neill, Frederick H; Atmar, Robert L; Katayama, Kazuhiko; Utama, Budi; Estes, Mary K

    2012-09-03

    Our previous report that the Norwalk virus nonstructural protein p22 is an antagonist of the cellular secretory pathway suggests a new aspect of norovirus/host interaction. To explore conservation of function of this highly divergent calicivirus protein, we examined the effects of p22 homologues from four human and two murine noroviruses, and feline calicivirus on the secretory pathway. All human noroviruses examined induced Golgi disruption and inhibited protein secretion, with the genogroup II.4 Houston virus being the most potent antagonist. Genogroup II.6 viruses have a conserved mutation in the mimic of an Endoplasmic Reticulum export signal (MERES) motif that is highly conserved in human norovirus homologues of p22 and is critical for secretory pathway antagonism, and these viruses had reduced levels of Golgi disruption and inhibition of protein secretion. p22 homologues from both persistent and nonpersistent strains of murine norovirus induced Golgi disruption, but only mildly inhibited cellular protein secretion. Feline calicivirus p30 did not induce Golgi disruption or inhibit cellular protein secretion. These differences confirm a norovirus-specific effect on host cell secretory pathway antagonism by homologues of p22, which may affect viral replication and/or cellular pathogenesis.

  3. 4-Oxalocrotonate tautomerase, its homologue YwhB, and active vinylpyruvate hydratase : Synthesis and evaluation of 2-fluoro substrate analogues

    NARCIS (Netherlands)

    Johnson, William H; Wang, Susan C; Stanley, Thanuja M; Czerwinski, Robert M; Almrud, Jeffrey J; Poelarends, Gerrit J; Murzin, Alexey G; Whitman, Christian P

    2004-01-01

    A series of 2-fluoro-4-alkene and 2-fluoro-4-alkyne substrate analogues were synthesized and examined as potential inhibitors of three enzymes: 4-oxalocrotonate tautomerase (4-OT) and vinylpyruvate hydratase (VPH) from the catechol meta-fission pathway and a closely related 4-OT homologue found in B

  4. The latrophilins, "split-personality" receptors.

    Science.gov (United States)

    Silva, John-Paul; Ushkaryov, Yuri A

    2010-01-01

    Latrophilin, a neuronal "adhesion-G protein-coupled receptor", is the major brain receptor for alpha-latrotoxin, a black widow spidertoxin which stimulates strong neuronal exocytosis in vertebrates. Latrophilin has an unusual structure consisting of two fragments that are produced by the proteolytic cleavage of the parental molecule and that behave independently in the plasma membrane. On binding an agonist, the fragments reassociate and send an intracellular signal. This signal, transduced by a heterotrimeric G protein, causes release of calcium from intracellular stores and massive release of neurotransmitters. Latrophilin represents a phylogenetically conserved family of receptors, with orthologues found in all animals and up to three homologues present in most chordate species. From mammalian homologues, latrophilins 1 and 3 are expressed in neurons, while latrophilin 2 is ubiquitous. Latrophilin 1 may control synapse maturation and exocytosis, whereas latrophilin 2 may be involved in breast cancer. Latrophilins may play different roles during development and in adult animals: thus, LAT-1 determines cell fate in early embryogenesis in Caenorhabditis elegans and controls neurotransmitter release in adult nematodes. This diversity suggests that the functions of latrophilins may be determined by their interactions with respective ligands. The finding of the ligand of latrophilin 1, the large postsynaptic protein lasso, is the first step in the quest for the physiological functions of latrophilins.

  5. Human cytomegalovirus UL7, a homologue of the SLAM-family receptor CD229, impairs cytokine production.

    Science.gov (United States)

    Engel, Pablo; Pérez-Carmona, Natàlia; Albà, M Mar; Robertson, Kevin; Ghazal, Peter; Angulo, Ana

    2011-10-01

    Human cytomegalovirus (HCMV), the β-herpesvirus prototype, has evolved a wide spectrum of mechanisms to counteract host immunity. Among them, HCMV uses cellular captured genes encoding molecules capable of interfering with the original host function or of fulfilling new immunomodulatory tasks. Here, we report on UL7, a novel HCMV heavily glycosylated transmembrane protein, containing an Ig-like domain that exhibits remarkable amino acid similarity to CD229, a cell-surface molecule of the signalling lymphocyte-activation molecule (SLAM) family involved in leukocyte activation. The UL7 Ig-like domain, which is well-preserved in all HCMV strains, structurally resembles the SLAM-family N-terminal Ig-variable domain responsible for the homophilic and heterophilic interactions that trigger signalling. UL7 is transcribed with early-late kinetics during the lytic infectious cycle. Using a mAb generated against the viral protein, we show that it is constitutively shed, through its mucine-like stalk, from the cell-surface. Production of soluble UL7 is enhanced by PMA and reduced by a broad-spectrum metalloproteinase inhibitor. Although UL7 does not hold the ability to interact with CD229 or other SLAM-family members, it shares with them the capacity to mediate adhesion to leukocytes, specifically to monocyte-derived DCs. Furthermore, we demonstrate that UL7 expression attenuates the production of proinflammatory cytokines TNF, IL-8 and IL-6 in DCs and myeloid cell lines. Thus, the ability of UL7 to interfere with cellular proinflammatory responses may contribute to viral persistence. These results enhance our understanding of those HCMV-encoded molecules involved in sustaining the balance between HCMV and the host immune system.

  6. Molecular piracy of chemokine receptors by herpesviruses.

    Science.gov (United States)

    Murphy, P M

    1994-01-01

    To succeed as a biological entity, viruses must exploit normal cellular functions and elude the host immune system; they often do so by molecular mimicry. One way that mimicry may occur is when viruses copy and modify host genes. The best studied examples of this are the oncogenes of RNA retroviruses, but a growing number of examples are also known for DNA viruses. So far they all come from just two groups of DNA viruses, the herpesviruses and poxviruses, and the majority of examples are for genes whose products regulate immune responses, such as cytokines, cytokine receptors, and complement control proteins. This review will focus on human and herpesvirus receptors for chemokines, a family of leukocyte chemoattractant and activating factors that are thought to be important mediators of inflammation. Although the biological roles of the viral chemokine receptor homologues are currently unknown, their connection to specific sets of chemokines has suggested a number of possible functions.

  7. Selective antagonists at group I metabotropic glutamate receptors: synthesis and molecular pharmacology of 4-aryl-3-isoxazolol amino acids

    DEFF Research Database (Denmark)

    Kromann, Hasse; Sløk, Frank A; Stensbøl, Tine B

    2002-01-01

    Homologation of (S)-glutamic acid (Glu, 1) and Glu analogues has previously provided ligands with activity at metabotropic Glu receptors (mGluRs). The homologue of ibotenic acid (7), 2-amino-3-(3-hydroxy-5-isoxazolyl)propionic acid (HIBO, 8), and the 4-phenyl derivative of 8, compound 9a, are bot...

  8. Structure, supramolecular organization and phase behavior of N-acyl-β-alanines: Structural homologues of mammalian brain constituents N-acylglycine and N-acyl-GABA.

    Science.gov (United States)

    Sivaramakrishna, D; Swamy, Musti J

    2016-12-01

    N-Acyl-β-alanines (NABAs) are structural homologues of N-acylglycines (NAGs) and N-acyl-γ-aminobutyric acids (NAGABAs), and achiral isomers of N-acylalanines, which are all present in mammalian brain and other tissues and modulate activity of biological receptors with various functions. In the present study, we synthesized and characterized a homologous series of NABAs bearing saturated acyl chains (n=8-20) and investigated their supramolecular organization and thermotropic phase behavior. In differential scanning calorimetric (DSC) studies, most of the NABAs gave one or two minor transitions before the main chain-melting phase transition in the dry state as well as upon hydration with water, but gave only a single transition when hydrated with buffer (pH7.6). Transition enthalpies (ΔHt) and entropies (ΔSt), obtained from the DSC studies showed linear dependence on the chain length in the dry state and upon hydration with buffer, whereas odd-even alteration was observed when hydrated with water. The crystal structures of N-lauroyl-β-alanine (NLBA) and N-myristoyl-β-alanine (NMBA) were solved in monoclinic system in the P21/c space group. Both NLBA and NMBA were packed in tilted bilayers with head-to-head (and tail-to-tail) arrangement with tilt angles of 33.28° and 34.42°, respectively. Strong hydrogen bonding interactions between COOH groups of the molecules from opposite leaflets as well as NH⋯O hydrogen bonds between the amide groups from adjacent molecules in the same leaflet as well as dispersion interactions between the acyl chains stabilize the bilayer structure. The d-spacings calculated from powder X-ray diffraction studies showed odd-even alteration with odd-chain length compounds exhibiting higher values as compared to the even-chain length ones and the tilt angles calculated from the PXRD data are higher for the even chain NABAs. These observations are relevant to developing structure-activity relationships for these amphiphiles and understand

  9. The soluble form of the membrane-bound transferrin homologue, melanotransferrin, inefficiently donates iron to cells via nonspecific internalization and degradation of the protein.

    Science.gov (United States)

    Food, Michael R; Sekyere, Eric O; Richardson, Des R

    2002-09-01

    Melanotransferrin (MTf) is a membrane-bound transferrin (Tf) homologue found particularly in melanoma cells. Apart from membrane-bound MTf, a soluble form of the molecule (sMTf) has been identified in vitro[Food, M.R., Rothenberger, S., Gabathuler, R., Haidl, I.D., Reid, G. & Jefferies, W.A. (1994) J. Biol. Chem.269, 3034-3040] and in vivo in Alzheimer's disease. However, nothing is known about the function of sMTf or its role in Fe uptake. In this study, sMTf labelled with 59Fe and 125I was used to examine its ability to donate 59Fe to SK-Mel-28 melanoma cells and other cell types. sMTf donated 59Fe to cells at 14% of the rate of Tf. Analysis of sMTf binding showed that unlike Tf, sMTf did not bind to a saturable Tf-binding site. Studies with Chinese hamster ovary cells with and without specific Tf receptors showed that unlike Tf, sMTf did not donate its 59Fe via these pathways. This was confirmed by experiments using lysosomotropic agents that markedly reduced 59Fe uptake from Tf, but had far less effect on 59Fe uptake from sMTf. In addition, an excess of 56Fe-labelled Tf or sMTf had no effect on 125I-labelled sMTf uptake, suggesting a nonspecific interaction of sMTf with cells. Protein-free 125I determinations demonstrated that in contrast with Tf, sMTf was markedly degraded. We suggest that unlike the binding of Tf to specific receptors, sMTf was donating Fe to cells via an inefficient mechanism involving nonspecific internalization and subsequent degradation.

  10. Identification of possible targets of the Aspergillus fumigatus CRZ1 homologue, CrzA

    Directory of Open Access Journals (Sweden)

    Goldman Gustavo H

    2010-01-01

    Full Text Available Abstract Background Calcineurin, a serine/threonine-specific protein phosphatase, plays an important role in the control of cell morphology and virulence in fungi. Calcineurin regulates localization and activity of a transcription factor called CRZ1. Recently, we characterize Aspergillus fumigatus CRZ1 homologue, AfCrzA. Here, we investigate which pathways are influenced by A. fumigatus AfCrzA during a short pulse of calcium by comparatively determining the transcriptional profile of A. fumigatus wild type and ΔAfcrzA mutant strains. Results We were able to observe 3,622 genes modulated in at least one timepoint in the mutant when compared to the wild type strain (3,211 and 411 at 10 and 30 minutes, respectively. Decreased mRNA abundance in the ΔcrzA was seen for genes encoding calcium transporters, transcription factors and genes that could be directly or indirectly involved in calcium metabolism. Increased mRNA accumulation was observed for some genes encoding proteins involved in stress response. AfCrzA overexpression in A. fumigatus increases the expression of several of these genes. The deleted strain of one of these genes, AfRcnA, belonging to a class of endogenous calcineurin regulators, calcipressins, had more calcineurin activity after exposure to calcium and was less sensitive to menadione 30 μM, hydrogen peroxide 2.5 mM, EGTA 25 mM, and MnCl2 25 mM. We constructed deletion, overexpression, and GFP fusion protein for the closely related A. nidulans AnRcnA. GFP::RcnA was mostly detected along the germling, did not accumulate in the nuclei and its location is not affected by the cellular response to calcium chloride. Conclusion We have performed a transcriptional profiling analysis of the A. fumigatus ΔAfcrzA mutant strain exposed to calcium stress. This provided an excellent opportunity to identify genes and pathways that are under the influence of AfCrzA. AfRcnA, one of these selected genes, encodes a modulator of calcineurin

  11. Identification of an AfsA homologue (BarX) from Streptomyces virginiae as a pleiotropic regulator controlling autoregulator biosynthesis, virginiamycin biosynthesis and virginiamycin M1 resistance.

    Science.gov (United States)

    Kawachi, R; Akashi, T; Kamitani, Y; Sy, A; Wangchaisoonthorn, U; Nihira, T; Yamada, Y

    2000-04-01

    Virginiae butanolide (VB)-BarA of Streptomyces virginiae is one of the newly discovered pairs of a gamma-butyrolactone autoregulator and the corresponding receptor protein of the Streptomyces species, and has been shown to regulate the production of antibiotic virginiamycin (VM) in S. virginiae. A divergently transcribed barX gene is situated 259 bp upstream of the barA gene, and the BarX protein has been shown to be highly homologous (39.8% identity, 74. 6% similarity) to S. griseus AfsA. Although AfsA is thought to be a biosynthetic enzyme for A-factor, another member of the family of gamma-butyrolactone autoregulators, the in vivo function of S. virginiae BarX was investigated in this study by phenotypic and transcriptional comparison between wild-type S. virginiae and a barX deletion mutant. With the same growth rate as wild-type S. virginiae on both solid and liquid media, the barX mutant showed no apparent changes in its morphological behaviour, indicating that barX does not participate in morphological control in S. virginiae. However, the barX mutant became more sensitive to virginiamycin M1 than did the wild-type strain (minimum inhibitory concentration, 50 microgram ml-1 compared with > 200 microgram ml-1) and exhibited reduced VB and VM production. The VM production was not restored by exogenous addition of VB, suggesting that BarX per se is not a biosynthetic enzyme of VBs but a pleiotropic regulatory protein controlling VB biosynthesis. DNA sequencing of a 5.6 kbp downstream region of barX revealed the presence of five open reading frames (ORFs): barZ, encoding a BarB-like regulatory protein; orf2, encoding a Streptomyces coelicolor RedD-like pathway specific regulator; varM, encoding a homologue of ATP-dependent transporters for macrolide antibiotics; orf4, encoding a homologue of beta-ketoacyl ACP/CoA reductase; and orf5, encoding a homologue of dNDP-glucose dehydratase. Reverse transcription polymerase chain reaction (RT-PCR) analyses of the

  12. Functional properties of Virus-Encoded and Virus-Regulated 7TM Receptors

    DEFF Research Database (Denmark)

    Spiess, Katja; Rosenkilde, Mette Marie

    2014-01-01

    During co-evolution with their hosts, viruses have developed several survival strategies that involve exploitation of 7TM receptors. These include virus-encoded 7TM receptors and ligands and viral regulation of endogenous receptors. Many functional properties have been ascribed to virus-exploited 7......-herpesvirus-encoded BILF1 receptors, the human cytomegalovirus (HCMV)-encoded US28 receptor and the Epstein-Barr virus (EBV)-regulated EBI2 (or GPR183), 2) the tissue tropism and virus-dissemination properties, exemplified by the murine CMV-encoded M33, and 3) the tumorigenic properties, exemplified...... by the human herpesvirus 8 (HHV8)-encoded ORF74, HCMV-US28 and EBV-BILF1. Given the general high “druggability” of 7TM receptors, and the recent progress in the understanding of in particular immune evasive functions of the virus-exploited 7TM receptors, we put a special emphasis on the progress of novel anti...

  13. Studies of the Cataluminescence of Benzene Homologues onNanosized γ–Al2O3/Eu2O3 and the Development of a Gas Sensorfor Benzene Homologue Vapors

    Directory of Open Access Journals (Sweden)

    Cuiqin Wu

    2006-12-01

    Full Text Available The cataluminescence (CTL of benzene and the benzene homologues tolueneand xylene on nanosized γ–Al2O3 doped with Eu2O3 (γ–Al2O3/Eu2O3 was studied and asensor of determining these gases was designed. The proposed sensor showed highsensitivity and selectivity at an optimal temperature of 432 ºC, a wavelength of 425 nm anda flow rate of 400 mL/min. Quantitative analysis was performed at the optimal conditions.The linear ranges of CTL intensity versus concentration of the benzene homologues were asfollows: benzene 2.4~5000 mL/m3, toluene 4.0~5000 mL/m3 and xylene 6.8~5000 mL/m3,with detection limits (3σ of 1.8 mL/m3, 3.0 mL/m3 and 3.4 mL/m3 for each one,respectively. The response time of this system was less than 3 s. The coexistence of othergases, such as SO2, CO and NH3, caused interference at levels around 11.7%, 5.8% and8.9% respectively. The technique is a convenient and fast way of determining the vapors ofbenzene homologues in air.

  14. A homologue of cathepsin L identified in conditioned medium from Sf9 insect cells.

    Science.gov (United States)

    Lindskog, Eva; Svensson, Ingrid; Häggström, Lena

    2006-07-01

    Gelatin zymography revealed the presence of proteolytic activity in conditioned medium (CM) from a serum-free, non-infected Spodoptera frugiperda, Sf9 insect cell culture. Two peptidase bands at about 49 and 39 kDa were detected and found to be proform and active form of the same enzyme. The 49-kDa form was visible on zymogram gels in samples of CM taken on days 4 and 5 of an Sf9 culture, while the 39-kDa form was seen on days 6 and 7. On basis of the inhibitor profile and substrate range, the enzyme was identified as an Sf9 homologue of cathepsin L, a papain-like cysteine peptidase. After lowering the pH of Sf9 CM to 3.5, an additional peptidase band at 22 kDa appeared. This peptidase showed the same inhibitor profile, substrate range and optimum pH (5.0) as the 39-kDa form, indicating that Sf9 cathepsin L has two active forms, at 39 and 22 kDa. Addition of the cysteine peptidase inhibitor E-64c to an Sf9 culture inhibited all proteolytic activities of Sf9 cathepsin L but did not influence the proliferation of Sf9 cells.

  15. GET_HOMOLOGUES, a versatile software package for scalable and robust microbial pangenome analysis.

    Science.gov (United States)

    Contreras-Moreira, Bruno; Vinuesa, Pablo

    2013-12-01

    GET_HOMOLOGUES is an open-source software package that builds on popular orthology-calling approaches making highly customizable and detailed pangenome analyses of microorganisms accessible to nonbioinformaticians. It can cluster homologous gene families using the bidirectional best-hit, COGtriangles, or OrthoMCL clustering algorithms. Clustering stringency can be adjusted by scanning the domain composition of proteins using the HMMER3 package, by imposing desired pairwise alignment coverage cutoffs, or by selecting only syntenic genes. The resulting homologous gene families can be made even more robust by computing consensus clusters from those generated by any combination of the clustering algorithms and filtering criteria. Auxiliary scripts make the construction, interrogation, and graphical display of core genome and pangenome sets easy to perform. Exponential and binomial mixture models can be fitted to the data to estimate theoretical core genome and pangenome sizes, and high-quality graphics can be generated. Furthermore, pangenome trees can be easily computed and basic comparative genomics performed to identify lineage-specific genes or gene family expansions. The software is designed to take advantage of modern multiprocessor personal computers as well as computer clusters to parallelize time-consuming tasks. To demonstrate some of these capabilities, we survey a set of 50 Streptococcus genomes annotated in the Orthologous Matrix (OMA) browser as a benchmark case. The package can be downloaded at http://www.eead.csic.es/compbio/soft/gethoms.php and http://maya.ccg.unam.mx/soft/gethoms.php.

  16. NRMT2 is an N-terminal monomethylase that primes for its homologue NRMT1.

    Science.gov (United States)

    Petkowski, Janusz J; Bonsignore, Lindsay A; Tooley, John G; Wilkey, Daniel W; Merchant, Michael L; Macara, Ian G; Schaner Tooley, Christine E

    2013-12-15

    NRMT (N-terminal regulator of chromatin condensation 1 methyltransferase) was the first eukaryotic methyltransferase identified to specifically methylate the free α-amino group of proteins. Since the discovery of this N-terminal methyltransferase, many new substrates have been identified and the modification itself has been shown to regulate DNA-protein interactions. Sequence analysis predicts one close human homologue of NRMT, METTL11B (methyltransferase-like protein 11B, now renamed NRMT2). We show in the present paper for the first time that NRMT2 also has N-terminal methylation activity and recognizes the same N-terminal consensus sequences as NRMT (now NRMT1). Both enzymes have similar tissue expression and cellular localization patterns. However, enzyme assays and MS experiments indicate that they differ in their specific catalytic functions. Although NRMT1 is a distributive methyltransferase that can mono-, di- and tri-methylate its substrates, NRMT2 is primarily a monomethylase. Concurrent expression of NRMT1 and NRMT2 accelerates the production of trimethylation, and we propose that NRMT2 activates NRMT1 by priming its substrates for trimethylation.

  17. A caseian point for the evolution of a diaphragm homologue among the earliest synapsids.

    Science.gov (United States)

    Lambertz, Markus; Shelton, Christen D; Spindler, Frederik; Perry, Steven F

    2016-12-01

    The origin of the diaphragm remains a poorly understood yet crucial step in the evolution of terrestrial vertebrates, as this unique structure serves as the main respiratory motor for mammals. Here, we analyze the paleobiology and the respiratory apparatus of one of the oldest lineages of mammal-like reptiles: the Caseidae. Combining quantitative bone histology and functional morphological and physiological modeling approaches, we deduce a scenario in which an auxiliary ventilatory structure was present in these early synapsids. Crucial to this hypothesis are indications that at least the phylogenetically advanced caseids might not have been primarily terrestrial but rather were bound to a predominantly aquatic life. Such a lifestyle would have resulted in severe constraints on their ventilatory system, which consequently would have had to cope with diving-related problems. Our modeling of breathing parameters revealed that these caseids were capable of only limited costal breathing and, if aquatic, must have employed some auxiliary ventilatory mechanism to quickly meet their oxygen demand upon surfacing. Given caseids' phylogenetic position at the base of Synapsida and under this aquatic scenario, it would be most parsimonious to assume that a homologue of the mammalian diaphragm had already evolved about 50 Ma earlier than previously assumed.

  18. Cloning the mouse homologue of the human lysosomal acid {alpha}-glucosidase gene

    Energy Technology Data Exchange (ETDEWEB)

    Ding, J.H.; Yang, B.Z.; Liu, H.M. [Duke Univ. Medical Center, Durham, NC (United States)] [and others

    1994-09-01

    Pompe disease (GSD II) is an autosomal recessive disorder caused by a deficiency of lysosomal acid {alpha}-glucosidase (GAA). In an attempt to create a mouse model for Pompe disease, we isolated and characterized the gene encoding the mouse homologue of the human GAA. Twenty clones that extend from exon 2 to the poly(A) tail were isolated from a mouse liver cDNA library, but the remainder of the mRNA proved difficult to obtain by conventional cDNA library screening. Sequences spanning exons 1-2 were cloned by RACE from mouse liver RNA. The full-length liver GAA cDNA contains 3365 nucleotides with a coding region of 2859 nucleotides and a 394 base pair 3{prime}-nontranslated region. The deduced amino acid sequence of the mouse GAA shows 84% identity to the human GAA. Southern blot analysis demonstrated that the mouse GAA was encoded by a single copy gene. Then six bacteriophages containing DNA from the GAA gene were isolated by screening 10{sup 6} phage plaques of a mouse 129 genomic library using a mouse GAA cDNA as a probe. From one of these bacteriophages, an 11-kilobase EcoRI fragment containing exons 3 to 15 was subcloned and sequenced. Work is in progress using this genomic clone to disrupt the GAA gene in murine embryonic stem cells in order to create GSD II mice.

  19. Characterization of a chaperone ClpB homologue of Paracoccidioides brasiliensis.

    Science.gov (United States)

    Jesuino, Rosália S A; Azevedo, Maristela O; Felipe, M Sueli S; Pereira, Maristela; De Almeida Soares, Célia M

    2002-08-01

    We report the cloning and sequence analysis of a genomic clone encoding a Paracoccidioides brasiliensis ClpB chaperone homologue (PbClpB). The clpb gene was identified in a lambda Dash II library. Sequencing of Pbclpb revealed a long open reading frame capable of encoding a 792 amino acid, 87.9 kDa protein, pI of 5.34. The predicted polypeptide contains several consensus motifs of the ClpB proteins. Canonical sequences such as two putative nucleotide-binding sites, chaperonins ClpA/B signatures and highly conserved casein kinase phosphorylation domains are present. ClpB is 69% to 49% identical to members of the ClpB family from several organisms from prokaryotes to eukaryotes. The transcript of PbclpB was detected as a mRNA species of 3.0 kb, preferentially expressed in the yeast parasitic phase of the fungus. A 89 kDa protein was also detected in yeast cells of P. brasiliensis.

  20. DNA Damage Induced MutS Homologue hMSH4 Acetylation

    Directory of Open Access Journals (Sweden)

    Chengtao Her

    2013-10-01

    Full Text Available Acetylation of non-histone proteins is increasingly recognized as an important post-translational modification for controlling the actions of various cellular processes including DNA repair and damage response. Here, we report that the human MutS homologue hMSH4 undergoes acetylation following DNA damage induced by ionizing radiation (IR. To determine which acetyltransferases are responsible for hMSH4 acetylation in response to DNA damage, potential interactions of hMSH4 with hTip60, hGCN5, and hMof were analyzed. The results of these experiments indicate that only hMof interacts with hMSH4 in a DNA damage-dependent manner. Intriguingly, the interplay between hMSH4 and hMof manipulates the outcomes of nonhomologous end joining (NHEJ-mediated DNA double strand break (DSB repair and thereby controls cell survival in response to IR. This study also shows that hMSH4 interacts with HDAC3, by which HDAC3 negatively regulates the levels of hMSH4 acetylation. Interestingly, elevated levels of HDAC3 correlate with increased NHEJ-mediated DSB repair, suggesting that hMSH4 acetylation per se may not directly affect the role of hMSH4 in DSB repair.

  1. The oil palm SHELL gene controls oil yield and encodes a homologue of SEEDSTICK.

    Science.gov (United States)

    Singh, Rajinder; Low, Eng-Ti Leslie; Ooi, Leslie Cheng-Li; Ong-Abdullah, Meilina; Ting, Ngoot-Chin; Nagappan, Jayanthi; Nookiah, Rajanaidu; Amiruddin, Mohd Din; Rosli, Rozana; Manaf, Mohamad Arif Abdul; Chan, Kuang-Lim; Halim, Mohd Amin; Azizi, Norazah; Lakey, Nathan; Smith, Steven W; Budiman, Muhammad A; Hogan, Michael; Bacher, Blaire; Van Brunt, Andrew; Wang, Chunyan; Ordway, Jared M; Sambanthamurthi, Ravigadevi; Martienssen, Robert A

    2013-08-15

    A key event in the domestication and breeding of the oil palm Elaeis guineensis was loss of the thick coconut-like shell surrounding the kernel. Modern E. guineensis has three fruit forms, dura (thick-shelled), pisifera (shell-less) and tenera (thin-shelled), a hybrid between dura and pisifera. The pisifera palm is usually female-sterile. The tenera palm yields far more oil than dura, and is the basis for commercial palm oil production in all of southeast Asia. Here we describe the mapping and identification of the SHELL gene responsible for the different fruit forms. Using homozygosity mapping by sequencing, we found two independent mutations in the DNA-binding domain of a homologue of the MADS-box gene SEEDSTICK (STK, also known as AGAMOUS-LIKE 11), which controls ovule identity and seed development in Arabidopsis. The SHELL gene is responsible for the tenera phenotype in both cultivated and wild palms from sub-Saharan Africa, and our findings provide a genetic explanation for the single gene hybrid vigour (or heterosis) attributed to SHELL, via heterodimerization. This gene mutation explains the single most important economic trait in oil palm, and has implications for the competing interests of global edible oil production, biofuels and rainforest conservation.

  2. Novel Type Ⅱ Peroxiredoxin Gene Homologue from Chinese Wildrye Enhancing Salt Stress Tolerance of Transgenic Yeast

    Institute of Scientific and Technical Information of China (English)

    YU Ying; LIU Xiang-guo; LU Yang; DOU Yao; WANG Hu-yi; HAN Si-ping; FENG Shu-dan; HAO Dong-yun

    2011-01-01

    Peroxiredoxins(Prxs)are a large family of antioxidant enzymes of various types that take part in signal transduction via decomposing reactive oxygen species(ROS).Although extensive efforts have been made over the last decades in understanding the structures and functions of Prxs,type Ⅱ Prxs in monocots are hardly studied.In this work,a monocot type Ⅱ Prx gene homologue from Chinese wildrye(Leymus Chinensis),designated as LcTpxⅡ,was isolated and characterized.LcTpxⅡ encoding a 162-amino acid protein contains a thioredoxin domain and a cysteine residue at position 51,suggesting that it is a member of the Prxs family.The LcTpxⅡ is capable of decomposing H2O2 and protecting plasmid DNA from damage caused by ROS.The expression of LcTpxⅡ in Chinese wildrye was induced by 400 mmol/L NaCl and 100 mmol/L Na2CO3 in the experiment.The overexpression of LcTpxⅡ enhances the tolerance of transgenic yeast to 1.6 mol/L NaCl and 10 mmol/L Na2CO3.

  3. Positive selection in AvrP4 avirulence gene homologues across the genus Melampsora.

    Science.gov (United States)

    Van der Merwe, Marlien M; Kinnear, Mark W; Barrett, Luke G; Dodds, Peter N; Ericson, Lars; Thrall, Peter H; Burdon, Jeremy J

    2009-08-22

    Pathogen genes involved in interactions with their plant hosts are expected to evolve under positive Darwinian selection or balancing selection. In this study a single copy avirulence gene, AvrP4, in the plant pathogen Melampsora lini, was used to investigate the evolution of such a gene across species. Partial translation elongation factor 1-alpha sequences were obtained to establish phylogenetic relationships among the Melampsora species. We amplified AvrP4 homologues from species pathogenic on hosts from different plant families and orders, across the inferred phylogeny. Translations of the AvrP4 sequences revealed a predicted signal peptide and towards the C-terminus of the protein, six identically spaced cysteines were identified in all sequences. Maximum likelihood analysis of synonymous versus non-synonymous substitution rates indicated that positive selection played a role in the evolution of the gene during the diversification of the genus. Fourteen codons under significant positive selection reside in the C-terminal 28 amino acid region, suggesting that this region interacts with host molecules in most sequenced accessions. Selection pressures on the gene may be either due to the pathogenicity or avirulence function of the gene or both.

  4. Characterization and expression analysis of an allograft inflammatory factor-1 homologue in yellow grouper (Epinephelus awoara)

    Institute of Scientific and Technical Information of China (English)

    WANG Li; SHI Dawei; WU Xinzhong

    2008-01-01

    Allograft inflammatory factor-1 (AIF-1) is a cytoplasmic calcium-binding protein involved in iullammatory response-related dis-eases in mammals.Previously an identified AIF-1 gene was simply reported in yellow grouper.The characterization of AIF-1 gene and its expression at the gene and protein level are further described.Yellow grouper AIF-1 is composed of 147 amino acids,and 64% ~ 84% identical to other homologues.Basal level AIF-I mRNA expression was noted in spleen,anterior kid-ney and kidney,using reverse-transcription polymerase chain reaction (RT-PCR).After stimulation of LPS,the AIF-1 mRNA expression was up-regulated in tissues examined:spleen,anterior kidney,kidney,heart and liver,but not in muscle.The re-combinant AIF-1 protein was expressed in Escherichia coli,and then purified for the development of antiserum.Western blotting analysis revealed a band with a molecular mass of about 17 ku.

  5. TRAUCO, a Trithorax-group gene homologue, is required for early embryogenesis in Arabidopsis thaliana.

    Science.gov (United States)

    Aquea, Felipe; Johnston, Amal J; Cañon, Paola; Grossniklaus, Ueli; Arce-Johnson, Patricio

    2010-02-01

    Embryogenesis is a critical stage during the plant life cycle in which a unicellular zygote develops into a multicellular organism. Co-ordinated gene expression is thus necessary for proper embryo development. Polycomb and Trithorax group genes are members of evolutionarily conserved machinery that maintains the correct expression patterns of key developmental regulators by repressing and activating gene transcription. TRAUCO (TRO), a gene homologous to the Trithorax group of genes that can functionally complement a BRE2P yeast mutant, has been identified in Arabidopsis thaliana. It is demonstrated that TRO is a nuclear gene product expressed during embryogenesis, and loss of TRO function leads to impaired early embryo development. Embryos that arrested at the globular stage in the tro-1 mutant allele were fully rescued by a TRO expression clone, a demonstration that the tro-1 mutation is a true loss-of-function in TRO. Our data have established that TRO is the first trithorax-group gene homologue in plants that is required for early embryogenesis.

  6. A Potato cDNA Encoding a Homologue of Mammalian Multidrug Resistant P-Glycoprotein

    Science.gov (United States)

    Wang, W.; Takezawa, D.; Poovaiah, B. W.

    1996-01-01

    A homologue of the multidrug resistance (MDR) gene was obtained while screening a potato stolon tip cDNA expression library with S-15-labeled calmodulin. The mammalian MDR gene codes for a membrane-bound P-glycoprotein (170-180 kDa) which imparts multidrug resistance to cancerous cells. The potato cDNA (PMDR1) codes for a polypeptide of 1313 amino acid residues (ca. 144 kDa) and its structural features are very similar to the MDR P-glycoprotein. The N-terminal half of the PMDR1-encoded protein shares striking homology with its C-terminal half, and each half contains a conserved ATP-binding site and six putative transmembrane domains. Southern blot analysis indicated that potato has one or two MDR-like genes. PMDR1 mRNA is constitutively expressed in all organs studied with higher expression in the stem and stolon tip. The PMDR1 expression was highest during tuber initiation and decreased during tuber development.

  7. TRBP and eIF6 homologue in Marsupenaeus japonicus play crucial roles in antiviral response.

    Directory of Open Access Journals (Sweden)

    Shuai Wang

    Full Text Available Plants and invertebrates can suppress viral infection through RNA silencing, mediated by RNA-induced silencing complex (RISC. Trans-activation response RNA-binding protein (TRBP, consisting of three double-stranded RNA-binding domains, is a component of the RISC. In our previous paper, a TRBP homologue in Fenneropenaeus chinensis (Fc-TRBP was reported to directly bind to eukaryotic initiation factor 6 (Fc-eIF6. In this study, we further characterized the function of TRBP and the involvement of TRBP and eIF6 in antiviral RNA interference (RNAi pathway of shrimp. The double-stranded RNA binding domains (dsRBDs B and C of the TRBP from Marsupenaeus japonicus (Mj-TRBP were found to mediate the interaction of TRBP and eIF6. Gel-shift assays revealed that the N-terminal of Mj-TRBP dsRBD strongly binds to double-stranded RNA (dsRNA and that the homodimer of the TRBP mediated by the C-terminal dsRBD increases the affinity to dsRNA. RNAi against either Mj-TRBP or Mj-eIF6 impairs the dsRNA-induced sequence-specific RNAi pathway and facilitates the proliferation of white spot syndrome virus (WSSV. These results further proved the important roles of TRBP and eIF6 in the antiviral response of shrimp.

  8. Crystal Structure of the Heterotrimer Core of Saccharomyces cerevisiae AMPK Homologue SNF1

    Energy Technology Data Exchange (ETDEWEB)

    Amodeo,G.; Rudolph, M.; Tong, L.

    2007-01-01

    AMP-activated protein kinase (AMPK) is a central regulator of energy homeostasis in mammals and is an attractive target for drug discovery against diabetes, obesity and other diseases. The AMPK homologue in Saccharomyces cerevisiae, known as SNF1, is essential for responses to glucose starvation as well as for other cellular processes, although SNF1 seems to be activated by a ligand other than AMP. Here we report the crystal structure at 2.6 resolution of the heterotrimer core of SNF1. The ligand-binding site in the {gamma}-subunit (Snf4) has clear structural differences from that of the Schizosaccharomyces pombe enzyme, although our crystallographic data indicate that AMP can also bind to Snf4. The glycogen-binding domain in the {beta}-subunit (Sip2) interacts with Snf4 in the heterotrimer but should still be able to bind carbohydrates. Our structure is supported by a large body of biochemical and genetic data on this complex. Most significantly, the structure reveals that part of the regulatory sequence in the {alpha}-subunit (Snf1) is sequestered by Snf4, demonstrating a direct interaction between the {alpha}- and {gamma}-subunits and indicating that our structure may represent the heterotrimer core of SNF1 in its activated state.

  9. The Oct4 homologue PouV and Nanog regulate pluripotency in chicken embryonic stem cells.

    Science.gov (United States)

    Lavial, Fabrice; Acloque, Hervé; Bertocchini, Federica; Macleod, David J; Boast, Sharon; Bachelard, Elodie; Montillet, Guillaume; Thenot, Sandrine; Sang, Helen M; Stern, Claudio D; Samarut, Jacques; Pain, Bertrand

    2007-10-01

    Embryonic stem cells (ESC) have been isolated from pregastrulation mammalian embryos. The maintenance of their pluripotency and ability to self-renew has been shown to be governed by the transcription factors Oct4 (Pou5f1) and Nanog. Oct4 appears to control cell-fate decisions of ESC in vitro and the choice between embryonic and trophectoderm cell fates in vivo. In non-mammalian vertebrates, the existence and functions of these factors are still under debate, although the identification of the zebrafish pou2 (spg; pou5f1) and Xenopus Pou91 (XlPou91) genes, which have important roles in maintaining uncommitted putative stem cell populations during early development, has suggested that these factors have common functions in all vertebrates. Using chicken ESC (cESC), which display similar properties of pluripotency and long-term self-renewal to mammalian ESC, we demonstrated the existence of an avian homologue of Oct4 that we call chicken PouV (cPouV). We established that cPouV and the chicken Nanog gene are required for the maintenance of pluripotency and self-renewal of cESC. These findings show that the mechanisms by which Oct4 and Nanog regulate pluripotency and self-renewal are not exclusive to mammals.

  10. A novel lipocalin homologue from the venom gland of Deinagkistrodon acutus similar to mammalian lipocalins

    Directory of Open Access Journals (Sweden)

    CB Wei

    2012-01-01

    Full Text Available Lipocalins are involved in a variety of functions including retinol transport, cryptic coloration, olfaction, pheromone transport, prostaglandin synthesis, regulation of the immune response and cell homeostatic mediation. A full-length cDNA clone (named d-lipo, isolated from the venom gland cDNA library of Deinagkistrodon acutus, contained an insert of 664 bp including an open reading frame that encodes a lipocalin homologue of 177 amino acids. Comparison of d-lipo and other related proteins revealed an overall amino acid identity of less than 21.5%. Primary structures of d-lipo carried three structurally conserved regions (SCR showing homologies to those of lipocalins. The first conserved Cys residue - the essential amino acid residue for the catalytic activity and unique to lipocalin-type prostaglandin D synthase (L-PGDS in the lipocalin protein family - was identified in d-lipo at amino acid position 58. Phylogenetic tree analysis showed that d-lipo was in-between the large L-PGDS cluster and the small von Ebner's-gland proteins (VEGP cluster. Moreover, d-lipo gene presented a high-level expression in the venom gland and a low-level expression in the brain and its expression was significantly increased under pathological conditions, suggesting a possible relationship between d-lipo mRNA expression and the venom gland inflammatory disease. This is also the first report of a lipocalin homologous gene identified in the venom gland of a snake.

  11. Crystallization and preliminary diffraction analysis of a DsbA homologue from Wolbachia pipientis

    Energy Technology Data Exchange (ETDEWEB)

    Kurz, M. [Institute for Molecular Bioscience and ARC Special Research Centre for Functional and Applied Genomics, University of Queensland, St Lucia, QLD 4072 (Australia); Iturbe-Ormaetxe, I. [School of Integrative Biology, The University of Queensland, St Lucia, QLD 4072 (Australia); Jarrott, R. [Institute for Molecular Bioscience and ARC Special Research Centre for Functional and Applied Genomics, University of Queensland, St Lucia, QLD 4072 (Australia); O’Neill, S. L. [School of Integrative Biology, The University of Queensland, St Lucia, QLD 4072 (Australia); Byriel, K. A.; Martin, J. L., E-mail: j.martin@imb.uq.edu.au; Heras, B., E-mail: j.martin@imb.uq.edu.au [Institute for Molecular Bioscience and ARC Special Research Centre for Functional and Applied Genomics, University of Queensland, St Lucia, QLD 4072 (Australia)

    2008-02-01

    The first crystallization of a W. pipientis protein, α-DsbA1, was achieved using hanging-drop and sitting-drop vapour diffusion. α-DsbA1 is one of two DsbA homologues encoded by the Gram-negative α-proteobacterium Wolbachia pipientis, an endosymbiont that can behave as a reproductive parasite in insects and as a mutualist in medically important filarial nematodes. The α-DsbA1 protein is thought to be important for the folding and secretion of Wolbachia proteins involved in the induction of reproductive distortions. Crystals of native and SeMet α-DsbA1 were grown by vapour diffusion and belong to the monoclinic space group C2, with unit-cell parameters a = 71.4, b = 49.5, c = 69.3 Å, β = 107.0° and one molecule in the asymmetric unit (44% solvent content). X-ray data were recorded from native crystals to a resolution of 2.01 Å using a copper anode and data from SeMet α-DsbA1 crystals were recorded to 2.45 Å resolution using a chromium anode.

  12. Characterization of the POU5F1 Homologue in Nile Tilapia: From Expression Pattern to Biological Activity.

    Science.gov (United States)

    Xiaohuan, Huang; Yang, Zhao; Linyan, Liu; Zhenhua, Fan; Linyan, Zhou; Zhijian, Wang; Ling, Wei; Deshou, Wang; Jing, Wei

    2016-09-15

    POU5F1 (OCT4) is a crucial transcription factor for induction and maintenance of cellular pluripotency, as well as survival of germ cells in mammals. However, the homologues of POU5F1 in teleost fish, including zebrafish and medaka, now named Pou5f3, exhibit considerable differences in expression pattern and pluripotency-maintaining activity. To what extent the POU5F1 homologues are conserved in vertebrates has been unclear. In this study, we report that the POU5F1 homologue from the Nile tilapia (Oreochromis niloticus), OnPou5f3, displays an expression pattern and biological activity somewhat different from those in zebrafish or medaka. The expression of Onpou5f3 at both mRNA and protein levels was abundant in early development embryos until blastula stages, barely detectable as proceeding, and then displayed a transiently strong expression domain in the brain region during neurula stages similar to zebrafish but not medaka. Afterward, OnPou5f3 appeared as germline-restricted (including primordial germ cells and female and male gonad germ cells) expression just like medaka. Notably, OnPou5f3 depletion through morpholino oligos caused blastula blockage or lethality and failure of survival and proliferation of blastula cell-derived cells. These findings indicate that equivalent POU5F1-like expression and activity of Pou5f3 might be conserved accompanying with species-specific expression pattern during evolution. Our study provides insight into the evolutionary conservation of the POU5F1 homologues across vertebrates.

  13. A new MOF-5 homologue for selective separation of methane from C2 hydrocarbons at room temperature

    Directory of Open Access Journals (Sweden)

    Yabing He

    2014-12-01

    Full Text Available A new MOF-5 homologue compound UTSA-10 has been obtained under solvothermal conditions from a mixture of Zn(NO32⋅6H2O and commercially available linker, 2-methylfumaric acid, in N,N-dimethylformamide. The moderate surface area and suitable pore sizes enable the activated UTSA-10a to separate methane from C2 hydrocarbons at room temperature.

  14. Identification of NoxD/Pro41 as the homologue of the p22phox NADPH oxidase subunit in fungi.

    Science.gov (United States)

    Lacaze, Isabelle; Lalucque, Hervé; Siegmund, Ulrike; Silar, Philippe; Brun, Sylvain

    2015-03-01

    NADPH oxidases (Nox) are membrane complexes that produce O2(-). Researches in mammals, plants and fungi highlight the involvement of Nox-generated ROS in cell proliferation, differentiation and defense. In mammals, the core enzyme gp91(phox)/Nox2 is associated with p22(phox) forming the flavocytochrome b558 ready for activation by a cytosolic complex. Intriguingly, no homologue of the p22(phox) gene has been found in fungal genomes, questioning how the flavoenzyme forms. Using whole genome sequencing combined with phylogenetic analysis and structural studies, we identify the fungal p22(phox) homologue as being mutated in the Podospora anserina mutant IDC(509). Functional studies show that the fungal p22(phox), PaNoxD, acts along PaNox1, but not PaNox2, a second fungal gp91(phox) homologue. Finally, cytological analysis of functional tagged versions of PaNox1, PaNoxD and PaNoxR shows clear co-localization of PaNoxD and PaNox1 and unravel a dynamic assembly of the complex in the endoplasmic reticulum and in the vacuolar system.

  15. Species-specific flight styles of flies are reflected in the response dynamics of a homologue motion sensitive neuron

    Directory of Open Access Journals (Sweden)

    Bart eGeurten

    2012-03-01

    Full Text Available Hoverflies and blowflies have distinctly different flight styles. Yet, both species have been shown to structure their flight behaviour in a way that facilitates extraction of 3D information from the image flow on the retina (optic flow. Neuronal candidates to analyse the optic flow are the tangential cells in the third optical ganglion – the lobula complex. These neurons are directionally selective and integrate the optic flow over large parts of the visual field. Homologue tangential cells in hoverflies and blowflies have a similar morphology. Because blowflies and hoverflies have similar neuronal layout but distinctly different flight behaviours, they are an ideal substrate to pinpoint potential neuronal adaptations to the different flight styles.In this article we describe the relationship between locomotion behaviour and motion vision on three different levels:1.We compare the different flight styles based on the categorisation of flight behaviour into prototypical movements.2.We measure the species specific dynamics of the optic flow under naturalistic flight conditions. We found the translational optic flow of both species to be very different.3.We describe possible adaptations of a homologue motion sensitive neuron. We stimulate this cell in blowflies (Calliphora and hoverflies (Eristalis with naturalistic optic flow generated by both species during free flight. The characterized hoverfly tangential cell responds faster to transient changes in the optic flow than its blowfly homologue. It is discussed whether and how the different dynamical response properties aid optic flow analysis.

  16. Cloning and characterization of Arabidopsis thaliana AtNAP57--a homologue of yeast pseudouridine synthase Cbf5p.

    Science.gov (United States)

    Maceluch, J; Kmieciak, M; Szweykowska-Kulińska, Z; Jarmołowski, A

    2001-01-01

    Rat Nap57 and its yeast homologue Cbf5p are pseudouridine synthases involved in rRNA biogenesis, localized in the nucleolus. These proteins, together with H/ACA class of snoRNAs compose snoRNP particles, in which snoRNA guides the synthase to direct site-specific pseudouridylation of rRNA. In this paper we present an Arabidopsis thaliana protein that is highly homologous to Cbf5p (72% identity and 85% homology) and NAP57 (67% identity and 81% homology). Moreover, the plant protein has conserved structural motifs that are characteristic features of pseudouridine synthases of the TruB class. We have named the cloned and characterized protein AtNAP57 (Arabidopsis thaliana homologue of NAP57). AtNAP57 is a 565 amino-acid protein and its calculated molecular mass is 63 kDa. The protein is encoded by a single copy gene located on chromosome 3 of the A. thaliana genome. Interestingly, the AtNAP57 gene does not contain any introns. Mutations in the human DKC1 gene encoding dyskerin (human homologue of yeast Cbf5p and rat NAP57) cause dyskeratosis congenita a rare inherited bone marrow failure syndrome characterized by abnormal skin pigmentation, nail dystrophy and mucosal leukoplakia.

  17. The OxyR homologue in Tannerella forsythia regulates expression of oxidative stress responses and biofilm formation.

    Science.gov (United States)

    Honma, Kiyonobu; Mishima, Elina; Inagaki, Satoru; Sharma, Ashu

    2009-06-01

    Tannerella forsythia is an anaerobic periodontal pathogen that encounters constant oxidative stress in the human oral cavity due to exposure to air and reactive oxidative species from coexisting dental plaque bacteria as well as leukocytes. In this study, we sought to characterize a T. forsythia ORF with close similarity to bacterial oxidative stress response sensor protein OxyR. To analyse the role of this OxyR homologue, a gene deletion mutant was constructed and characterized. Aerotolerance, survival after hydrogen peroxide challenge and transcription levels of known bacterial antioxidant genes were then determined. Since an association between oxidative stress and biofilm formation has been observed in bacterial systems, we also investigated the role of the OxyR protein in biofilm development by T. forsythia. Our results showed that aerotolerance, sensitivity to peroxide challenge and the expression of oxidative stress response genes were significantly reduced in the mutant as compared with the wild-type strain. Moreover, the results of biofilm analyses showed that, as compared with the wild-type strain, the oxyR mutant showed significantly less autoaggregation and a reduced ability to form mixed biofilms with Fusobacterium nucleatum. In conclusion, a gene annotated in the T. forsythia genome as an oxyR homologue was characterized. Our studies showed that the oxyR homologue in T. forsythia constitutively activates antioxidant genes involved in resistance to peroxides as well as oxygen stress (aerotolerance). In addition, the oxyR deletion attenuates biofilm formation in T. forsythia.

  18. Virus-Encoded 7 Transmembrane Receptors

    DEFF Research Database (Denmark)

    Mølleskov-Jensen, Ann-Sofie; Oliveira, MarthaTrindade; Farrell, Helen Elizabeth

    2015-01-01

    Herpesviruses are an ancient group which have exploited gene capture of multiple cellular modulators of the immune response. Viral homologues of 7 transmembrane receptors (v7TMRs) are a consistent feature of beta- and gammaherpesviruses; the majority of the v7TMRs are homologous to cellular...... chemokine receptors (CKRs). Conserved families of v7TMRs distinguish between beta- versus gammaherpesviruses; furthermore, significant divisions within these subfamilies, such as between genera of the gammaherpesviruses or between the primate and rodent cytomegaloviruses, coincide with specific v7TMR gene...... families. Divergence of functional properties between the viral 7TMR and their cellular counterparts is likely, therefore, to reflect adaptation supporting various aspects of the viral lifecycle with concomitant effects upon viral pathogenesis. Consistent with their long evolutionary history, the v7TMRs...

  19. A novel salting-out assisted extraction coupled with HPLC- fluorescence detection for trace determination of vitamin K homologues in human plasma.

    Science.gov (United States)

    Ahmed, Sameh; Mahmoud, Ashraf M

    2015-11-01

    Recently, new physiological roles of vitamin K homologues have been established in the treatment of rheumatoid arthritis, osteoporosis, hepatocellular carcinoma and leukemia. However, relatively high plasma protein binding, low plasma concentrations and occurrences of interfering lipids make accurate determination of vitamin K homologues a challenging task. Therefore, a sensitive and reliable salting-out assisted liquid/liquid extraction (SALLE) method coupled with HPLC-Fluorescence detection was designed for efficient extraction and quantification of trace levels of vitamin K homologues in human plasma. The investigated vitamin K homologues were phylloquinone (PK, vitamin K1), menaquinone-4 (MK-4) and menaquinone-7 (MK-7). The method employed a new efficient fluorescence derivatization reaction using ethanolic solution of stannous chloride in acidic solution to generate highly fluorescent naphthohydroquinone derivatives. Correlation coefficients were more than 0.998 in the concentration ranges of 0.3-100 ng mL(-1) with detection limits of 0.1-0.17 ng mL(-1) in human plasma. The developed HPLC-FL system was successfully applied for sensitive determination of vitamin K homologues in plasma of healthy volunteers. The developed method may provide a valuable tool in the pharmacoinformatic studies concerning the roles of vitamin K homologues.

  20. Characterization of the promoter and extended C-terminal domain of Arabidopsis WRKY33 and functional analysis of tomato WRKY33 homologues in plant stress responses.

    Science.gov (United States)

    Zhou, Jie; Wang, Jian; Zheng, Zuyu; Fan, Baofang; Yu, Jing-Quan; Chen, Zhixiang

    2015-08-01

    Arabidopsis AtWRKY33 plays a critical role in broad plant stress responses. Whether there are evolutionarily conserved homologues of AtWRKY33 in other plants and what make AtWRKY33 such an important protein in plant stress responses are largely unknown. We compared AtWRKY33 with its close homologues to identify AtWRKY33-specific regulatory and structural elements, which were then functionally analysed through complementation. We also performed phylogenetic analysis to identify structural AtWRKY33 homologues in other plants and functionally analysed two tomato homologues through complementation and gene silencing. AtWRKY33 has an extended C-terminal domain (CTD) absent in its close homologue AtWRKY25. Both its CTD and the strong pathogen/stress-responsive expression of AtWRKY33 are necessary to complement the critical phenotypes of atwrky33. Structural AtWRKY33 homologues were identified in both dicot and monocot plants including two (SlWRKY33A and SlWRKY33B) in tomato. Molecular complementation and gene silencing confirmed that the two tomato WRKY genes play a critical role similar to that of AtWRKY33 in plant stress responses. Thus, WRKY33 proteins are evolutionarily conserved with a critical role in broad plant stress responses. Both its CTD and promoter are critical for the uniquely important roles of WRKY33 in plant stress responses.

  1. miR-210 Targets Iron-Sulfur Cluster Scaffold Homologue in Human Trophoblast Cell Lines

    Science.gov (United States)

    Lee, Deug-Chan; Romero, Roberto; Kim, Jung-Sun; Tarca, Adi L.; Montenegro, Daniel; Pineles, Beth L.; Kim, Ernest; Lee, JoonHo; Kim, Sun Young; Draghici, Sorin; Mittal, Pooja; Kusanovic, Juan Pedro; Chaiworapongsa, Tinnakorn; Hassan, Sonia S.; Kim, Chong Jai

    2011-01-01

    This study was performed to assess the biological significance of miR-210 in preeclampsia and small-for-gestational-age (SGA) pregnancies. Placental miR-210 expression was evaluated by quantitative RT-PCR (RT-qPCR) in the following groups: i) appropriate-for-gestational-age pregnancies (n = 72), ii) preeclampsia (n = 52), iii) SGA (n = 66), and iv)preeclampsia with SGA (n = 31). The effects of hypoxia (1% O2) on miR-210 and iron-sulfur cluster scaffold homologue (ISCU) expressions and miR-210 binding to ISCU 3′ UTR were examined in Swan 71 and BeWo cell lines. Perls' reaction (n = 229) and electron microscopy (n = 3) were conducted to verify siderosis of trophoblasts. miR-210 expression was increased in preeclampsia and SGA cases and was decreased with birth weight and gestational age. In both cell lines, miR-210 was induced by hypoxia, whereas ISCU expression was decreased. The luciferase assay confirmed miR-210 binding to ISCU mRNA 3′ UTR. RNA interference knockdown of ISCU expression in Swan 71, but not in BeWo, cells resulted in autophagosomal and siderosomal iron accumulation and a fourfold decrease of Matrigel invasion (P = 0.004). Placental ISCU expression was decreased in preeclampsia (P = 0.002) and SGA (P = 0.002) cases. Furthermore, hemosiderin-laden trophoblasts were more frequent in the placental bed of preterm preeclampsia and/or SGA births than in control cases (48.7% versus 17.9%; P = 0.004). Siderosis of interstitial trophoblasts is a novel pathological feature of preeclampsia and SGA. The findings herein suggest that ISCU down-regulation by miR-210 perturbing trophoblast iron metabolism is associated with defective placentation. PMID:21801864

  2. Regulatory elements and transcriptional control of chicken vasa homologue (CVH) promoter in chicken primordial germ cells.

    Science.gov (United States)

    Jin, So Dam; Lee, Bo Ram; Hwang, Young Sun; Lee, Hong Jo; Rim, Jong Seop; Han, Jae Yong

    2017-01-01

    Primordial germ cells (PGCs), the precursors of functional gametes, have distinct characteristics and exhibit several unique molecular mechanisms to maintain pluripotency and germness in comparison to somatic cells. They express germ cell-specific RNA binding proteins (RBPs) by modulating tissue-specific cis- and trans-regulatory elements. Studies on gene structures of chicken vasa homologue (CVH), a chicken RNA binding protein, involved in temporal and spatial regulation are thus important not only for understanding the molecular mechanisms that regulate germ cell fate, but also for practical applications of primordial germ cells. However, very limited studies are available on regulatory elements that control germ cell-specific expression in chicken. Therefore, we investigated the intricate regulatory mechanism(s) that governs transcriptional control of CVH. We constructed green fluorescence protein (GFP) or luciferase reporter vectors containing the various 5' flanking regions of CVH gene. From the 5' deletion and fragmented assays in chicken PGCs, we have identified a CVH promoter that locates at -316 to +275 base pair fragment with the highest luciferase activity. Additionally, we confirmed for the first time that the 5' untranslated region (UTR) containing intron 1 is required for promoter activity of the CVH gene in chicken PGCs. Furthermore, using a transcription factor binding prediction, transcriptome analysis and siRNA-mediated knockdown, we have identified that a set of transcription factors play a role in the PGC-specific CVH gene expression. These results demonstrate that cis-elements and transcription factors localizing in the 5' flanking region including the 5' UTR and an intron are important for transcriptional regulation of the CVH gene in chicken PGCs. Finally, this information will contribute to research studies in areas of reproductive biology, constructing of germ cell-specific synthetic promoter for tracing primordial germ cells as well as

  3. Engineering the glutamate transporter homologue GltPh using protein semisynthesis.

    Science.gov (United States)

    Focke, Paul J; Annen, Alvin W; Valiyaveetil, Francis I

    2015-03-03

    Glutamate transporters catalyze the concentrative uptake of glutamate from synapses and are essential for normal synaptic function. Despite extensive investigations of glutamate transporters, the mechanisms underlying substrate recognition, ion selectivity, and the coupling of substrate and ion transport are not well-understood. Deciphering these mechanisms requires the ability to precisely engineer the transporter. In this study, we describe the semisynthesis of GltPh, an archaeal homologue of glutamate transporters. Semisynthesis allows the precise engineering of GltPh through the incorporation of unnatural amino acids and peptide backbone modifications. In the semisynthesis, the GltPh polypeptide is initially assembled from a recombinantly expressed thioester peptide and a chemically synthesized peptide using the native chemical ligation reaction followed by in vitro folding to the native state. We have developed a robust procedure for the in vitro folding of GltPh. Biochemical characterization of the semisynthetic GltPh indicates that it is similar to the native transporter. We used semisynthesis to substitute Arg397, a highly conserved residue in the substrate binding site, with the unnatural analogue, citrulline. Our studies demonstrate that Arg397 is required for high-affinity substrate binding, and on the basis of our results, we propose that Arg397 is involved in a Na+-dependent remodeling of the substrate binding site required for high-affinity Asp binding. We anticipate that the semisynthetic approach developed in this study will be extremely useful in investigating functional mechanisms in GltPh. Further, the approach developed in this study should also be applicable to other membrane transport proteins.

  4. The Mode of Hedgehog Binding to Ihog Homologues is Not Conserved Across Different Phyla

    Energy Technology Data Exchange (ETDEWEB)

    McLellan, J.; Zheng, X; Hauk, G; Ghirlando, R; Beachy, P; Leahy, D

    2008-01-01

    Hedgehog (Hh) proteins specify tissue pattern in metazoan embryos by forming gradients that emanate from discrete sites of expression and elicit concentration-dependent cellular differentiation or proliferation responses1, 2. Cellular responses to Hh and the movement of Hh through tissues are both precisely regulated, and abnormal Hh signalling has been implicated in human birth defects and cancer3, 4, 5, 6, 7. Hh signalling is mediated by its amino-terminal domain (HhN), which is dually lipidated and secreted as part of a multivalent lipoprotein particle8, 9, 10. Reception of the HhN signal is modulated by several cell-surface proteins on responding cells, including Patched (Ptc), Smoothened (Smo), Ihog (known as CDO or CDON in mammals) and the vertebrate-specific proteins Hip (also known as Hhip) and Gas1 (ref. 11). Drosophila Ihog and its vertebrate homologues CDO and BOC contain multiple immunoglobulin and fibronectin type III (FNIII) repeats, and the first FNIII repeat of Ihog binds Drosophila HhN in a heparin-dependent manner12, 13. Surprisingly, pull-down experiments suggest that a mammalian Sonic hedgehog N-terminal domain (ShhN) binds a non-orthologous FNIII repeat of CDO12, 14. Here we report biochemical, biophysical and X-ray structural studies of a complex between ShhN and the third FNIII repeat of CDO. We show that the ShhN-CDO interaction is completely unlike the HhN-Ihog interaction and requires calcium, which binds at a previously undetected site on ShhN. This site is conserved in nearly all Hh proteins and is a hotspot for mediating interactions between ShhN and CDO, Ptc, Hip and Gas1. Mutations in vertebrate Hh proteins causing holoprosencephaly and brachydactyly type A1 map to this calcium-binding site and disrupt interactions with these partners.

  5. Characterization of two 20kDa-cement protein (cp20k homologues in Amphibalanus amphitrite.

    Directory of Open Access Journals (Sweden)

    Li-Sheng He

    Full Text Available The barnacle, Amphibalanus amphitrite, is a common marine fouling organism. Understanding the mechanism of barnacle adhesion will be helpful in resolving the fouling problem. Barnacle cement is thought to play a key role in barnacle attachment. Although several adult barnacle cement proteins have been identified in Megabalanus rosa, little is known about their function in barnacle settlement. In this study, two homologous 20k-cement proteins (cp20k in Amphibalanus amphitrite, named Bamcp20k-1 and Bamcp20k-2, were characterized. The two homologues share primary sequence structure with proteins from other species including Megabalanus rosa and Fistulobalanus albicostatus. The conserved structure included repeated Cys domains and abundant charged amino acids, such as histidine. In this study we demonstrated that Bamcp20k-1 localized at the α secretory cells in the cyprid cement gland, while Bamcp20k-2 localized to the β secretory cells. The differential localizations suggest differential regulation for secretion from the secretory cells. Both Bamcp20k-1 and Bamcp20k-2 from cyprids dissolved in PBS. However, adult Bamcp20k-2, which was dominant in the basal shell of adult barnacles, was largely insoluble in PBS. Solubility increased in the presence of the reducing reagent Dithiothreitol (DTT, suggesting that the formation of disulfide bonds plays a role in Bamcp20k-2 function. In comparison, Bamcp20k-1, which was enriched in soft tissue, could not be easily detected in the shell and base by Western blot and easily dissolved in PBS. These differential solubilities and localizations indicate that Bamcp20k-1 and Bamcp20k-2 have distinct functions in barnacle cementing.

  6. The Drosophila Arf1 homologue Arf79F is essential for lamellipodium formation

    Science.gov (United States)

    Humphreys, Daniel; Liu, Tao; Davidson, Anthony C.; Hume, Peter J.; Koronakis, Vassilis

    2012-01-01

    Summary The WAVE regulatory complex (WRC) drives the polymerisation of actin filaments located beneath the plasma membrane to generate lamellipodia that are pivotal to cell architecture and movement. By reconstituting WRC-dependent actin assembly at the membrane, we recently discovered that several classes of Arf family GTPases directly recruit and activate WRC in cell extracts, and that Arf cooperates with Rac1 to trigger actin polymerisation. Here, we demonstrate that the Class 1 Arf1 homologue Arf79F colocalises with the WRC at dynamic lamellipodia. We report that Arf79F is required for lamellipodium formation in Drosophila S2R+ cells, which only express one Arf isoform for each class. Impeding Arf function either by dominant-negative Arf expression or by Arf double-stranded RNA interference (dsRNAi)-mediated knockdown uncovered that Arf-dependent lamellipodium formation was specific to Arf79F, establishing that Class 1 Arfs, but not Class 2 or Class 3 Arfs, are crucial for lamellipodia. Lamellipodium formation in Arf79F-silenced cells was restored by expressing mammalian Arf1, but not by constitutively active Rac1, showing that Arf79F does not act via Rac1. Abolition of lamellipodium formation in Arf79F-silenced cells was not due to Golgi disruption. Blocking Arf79F activation with guanine nucleotide exchange factor inhibitors impaired WRC localisation to the plasma membrane and concomitant generation of lamellipodia. Our data indicate that the Class I Arf GTPase is a central component in WRC-driven lamellipodium formation. PMID:22992458

  7. SQL-1, homologue of the Golgi protein GMAP210, modulates intraflagellar transport in C. elegans.

    Science.gov (United States)

    Broekhuis, Joost R; Rademakers, Suzanne; Burghoorn, Jan; Jansen, Gert

    2013-04-15

    Primary cilia are microtubule-based organelles that have important sensory functions. For their function, cilia rely on the delivery of specific proteins, both by intracellular trafficking and intraflagellar transport (IFT). In the cilia of Caenorhabditis elegans, anterograde IFT is mediated by kinesin-II and OSM-3. Previously, we have shown that expression of a dominant active G protein α subunit (GPA-3QL) in amphid channel neurons affects the coordination of kinesin-II and OSM-3 and also affects cilia length, suggesting that environmental signals can modulate these processes. Here, we show that loss-of-function of sql-1 (suppressor of gpa-3QL 1), which encodes the homologue of the mammalian Golgi protein GMAP210, suppresses the gpa-3QL cilia length phenotype. SQL-1 localizes to the Golgi apparatus, where it contributes to maintaining Golgi organization. Loss of sql-1 by itself does not affect cilia length, whereas overexpression of sql-1 results in longer cilia. Using live imaging of fluorescently tagged IFT proteins, we show that in sql-1 mutants OSM-3 moves faster, kinesin-II moves slower and that some complex A and B proteins move at an intermediate velocity, while others move at the same velocity as OSM-3. This indicates that mutation of sql-1 destabilizes the IFT complex. Finally, we show that simultaneous inactivation of sql-1 and activation of gpa-3QL affects the velocity of OSM-3. In summary, we show that in C. elegans the Golgin protein SQL-1 plays an important role in maintaining the stability of the IFT complex.

  8. A La autoantigen homologue is required for the internal ribosome entry site mediated translation of giardiavirus.

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    Srinivas Garlapati

    Full Text Available Translation of Giardiavirus (GLV mRNA is initiated at an internal ribosome entry site (IRES in the viral transcript. The IRES localizes to a downstream portion of 5' untranslated region (UTR and a part of the early downstream coding region of the transcript. Recent studies indicated that the IRES does not require a pre-initiation complex to initiate translation but may directly recruit the small ribosome subunit with the help of a number of trans-activating protein factors. A La autoantigen homologue in the viral host Giardia lamblia, GlLa, was proposed as one of the potential trans-activating factors based on its specific binding to GLV-IRES in vitro. In this study, we further elucidated the functional role of GlLa in GLV-IRES mediated translation in Giardia by knocking down GlLa with antisense morpholino oligo, which resulted in a reduction of GLV-IRES activity by 40%. An over-expression of GlLa in Giardia moderately stimulated GLV-IRES activity by 20%. A yeast inhibitory RNA (IRNA, known to bind mammalian and yeast La autoantigen and inhibit Poliovirus and Hepatitis C virus IRES activities in vitro and in vivo, was also found to bind to GlLa protein in vitro and inhibited GLV-IRES function in vivo. The C-terminal domain of La autoantigen interferes with the dimerization of La and inhibits its function. An over-expression of the C-terminal domain (200-348aa of GlLa in Giardia showed a dominant-negative effect on GLV-IRES activity, suggesting a potential inhibition of GlLa dimerization. HA tagged GlLa protein was detected mainly in the cytoplasm of Giardia, thus supporting a primary role of GlLa in translation initiation in Giardiavirus.

  9. Diversity in domain architectures of Ser/Thr kinases and their homologues in prokaryotes

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    Krupa A

    2005-09-01

    Full Text Available Abstract Background Ser/Thr/Tyr kinases (STYKs commonly found in eukaryotes have been recently reported in many bacterial species. Recent studies elucidating their cellular functions have established their roles in bacterial growth and development. However functions of a large number of bacterial STYKs still remain elusive. The organisation of domains in a large dataset of bacterial STYKs has been investigated here in order to recognise variety in domain combinations which determine functions of bacterial STYKs. Results Using sensitive sequence and profile search methods, domain organisation of over 600 STYKs from 125 prokaryotic genomes have been examined. Kinase catalytic domains of STYKs tethered to a wide range of enzymatic domains such as phosphatases, HSP70, peptidyl prolyl isomerases, pectin esterases and glycoproteases have been identified. Such distinct preferences for domain combinations are not known to be present in either the Histidine kinase or the eukaryotic STYK families. Domain organisation of STYKs specific to certain groups of bacteria has also been noted in the current anlaysis. For example, Hydrophobin like domains in Mycobacterial STYK and penicillin binding domains in few STYKs of Gram-positive organisms and FHA domains in cyanobacterial STYKs. Homologues of characterised substrates of prokaryotic STYKs have also been identified. Conclusion The domains and domain architectures of most of the bacterial STYKs identified are very different from the known domain organisation in STYKs of eukaryotes. This observation highlights distinct biological roles of bacterial STYKs compared to eukaryotic STYKs. Bacterial STYKs reveal high diversity in domain organisation. Some of the modular organisations conserved across diverse bacterial species suggests their central role in bacterial physiology. Unique domain architectures of few other groups of STYKs reveal recruitment of functions specific to the species.

  10. Phagosome maturation in unicellular eukaryote Paramecium: the presence of RILP, Rab7 and LAMP-2 homologues.

    Science.gov (United States)

    Wyroba, E; Surmacz, L; Osinska, M; Wiejak, J

    2007-01-01

    Phagosome maturation is a complex process enabling degradation of internalised particles. Our data obtained at the gene, protein and cellular level indicate that the set of components involved in this process and known up to now in mammalian cells is functioning in unicellular eukaryote. Rab7-interacting partners: homologues of its effector RILP (Rab-interacting lysosomal protein) and LAMP-2 (lysosomal membrane protein 2) as well as alpha7 subunit of the 26S proteasome were revealed in Paramecium phagolysosomal compartment. We identified the gene/transcript fragments encoding RILP-related proteins (RILP1 and RILP2) in Paramecium by PCR/RT-PCR and sequencing. The deduced amino acid sequences of RILP1 and RILP2 show 60.5% and 58.3% similarity, respectively, to the region involved in regulating of lysosomal morphology and dynein-dynactin recruitment of human RILP. RILP colocalised with Rab7 in Paramecium lysosomes and at phagolysosomal membrane during phagocytosis of both the latex beads and bacteria. In the same compartment LAMP-2 was present and its expression during latex internalisation was 2.5-fold higher than in the control when P2 protein fractions (100,000 x g) of equal load were quantified by immunoblotting. LAMP-2 cross-reacting polypeptide of approximately106 kDa was glycosylated as shown by fluorescent and Western analysis of the same blot preceded by PNGase F treatment. The alpha7 subunit of 26S proteasome was detected close to the phagosomal membrane in the small vesicles, in some of which it colocalised with Rab7. Immunoblotting confirmed presence of RILP-related polypeptide and a7 subunit of 26S proteasome in Paramecium protein fractions. These results suggest that Rab7, RILP and LAMP-2 may be involved in phagosome maturation in Paramecium.

  11. Identification and characterization of functional Smad8 and Smad4 homologues from Echinococcus granulosus.

    Science.gov (United States)

    Zhang, Chuanshan; Wang, Limin; Wang, Hui; Pu, Hongwei; Yang, Le; Li, Jing; Wang, Junhua; Lü, Guodong; Lu, Xiaomei; Zhang, Wenbao; Vuitton, Dominique A; Wen, Hao; Lin, Renyong

    2014-10-01

    Smad family proteins are essential cellular mediators of the transforming growth factor-β superfamily. In the present study, we identified two members of the Smad proteins, Smad8 and Smad4 homologues (termed as EgSmadE and EgSmadD, respectively), from Echinococcus granulosus, the causative agent of cystic echinococcosis (CE). Phylogenetic analysis placed EgSmadE in the Smad1, 5, and 8 subgroup of the R-Smad sub-family and EgSmadD in the Co-Smad family. Furthermore, EgSmadE and EgSmadD attained a high homology to EmSmadE and EmSmadD of E. multilocularis, respectively. Both EgSmadE and EgSmadD were co-expressed in the larval stages and exhibited the highest transcript levels in activated protoscoleces, and their encoded proteins were co-localized in the sub-tegumental and tegumental layer of the parasite. As shown by yeast two-hybrid and pull-down analysis, EgSmadE displayed a positive binding interaction with EgSmadD. In addition, EgSmadE localized in the nuclei of Mv1Lu cells (mink lung epithelial cells) upon treatment with human TGF-β1 or human BMP2, indicating that EgSmadE is capable of being translocated into nucleus, in vitro. Our study suggests that EgSmadE and EgSmadD may take part in critical biological processes, including echinococcal growth, development, and parasite-host interaction.

  12. Development and mapping of SSR markers linked to resistance-gene homologue clusters in common bean

    Institute of Scientific and Technical Information of China (English)

    Luz; Nayibe; Garzon; Matthew; Wohlgemuth; Blair

    2014-01-01

    Common bean is an important but often a disease-susceptible legume crop of temperate,subtropical and tropical regions worldwide. The crop is affected by bacterial, fungal and viral pathogens. The strategy of resistance-gene homologue(RGH) cloning has proven to be an efficient tool for identifying markers and R(resistance) genes associated with resistances to diseases. Microsatellite or SSR markers can be identified by physical association with RGH clones on large-insert DNA clones such as bacterial artificial chromosomes(BACs). Our objectives in this work were to identify RGH-SSR in a BAC library from the Andean genotype G19833 and to test and map any polymorphic markers to identify associations with known positions of disease resistance genes. We developed a set of specific probes designed for clades of common bean RGH genes and then identified positive BAC clones and developed microsatellites from BACs having SSR loci in their end sequences. A total of 629 new RGH-SSRs were identified and named BMr(bean microsatellite RGH-associated markers). A subset of these markers was screened for detecting polymorphism in the genetic mapping population DOR364 × G19833. A genetic map was constructed with a total of 264 markers,among which were 80 RGH loci anchored to single-copy RFLP and SSR markers. Clusters of RGH-SSRs were observed on most of the linkage groups of common bean and in positions associated with R-genes and QTL. The use of these new markers to select for disease resistance is discussed.

  13. Synthesis, Electrochemistry and Electrogenerated Chemiluminesce of two BODIPY-Appended Bipyridine Homologues

    Science.gov (United States)

    Qi, Honglan; Teesdale, Justin J.; Pupillo, Rachel C.

    2014-01-01

    Two new 2,2’-bipyridine (bpy) derivatives containing ancillary BODIPY chromophores attached at the 5- and 5’-positions (BB3) or 6- and 6’-positions (BB4) were prepared and characterized. In this work, the basic photophysics, electrochemistry and electrogenerated chemiluminescence (ECL) of BB3 and BB4 are compared with those previously reported for a related bpy-BODIPY derivative (BB2) (J. Phys. Chem. C 2011, 115, 17993–18001). Cyclic voltammetry revealed that BB3 and BB4 display reversible 2e− oxidation and reduction waves, which consist of two closely spaced (50 – 70 mV) 1e− events. This redox behavior is consistent with the frontier molecular orbitals calculated for BB3 and BB4 and indicates that the 2,2’-bipyridine spacer of each bpy- BODIPY homologue does not facilitate efficient electronic communication between the tethered indacene units. In the presence of a coreactant such as tri-n-propylamine (TPA) or benzoyl peroxide (BPO), BB3 and BB4 exhibit strong ECL and produce spectra that are very similar to their corresponding photoluminescence profiles. The ECL signal obtained under annihilation conditions, however, is significantly different and is characterized by two distinct bands. One of these bands is centered at ~570 nm and is attributed to emission via an S- or T-route. The second band, occurs at longer wavelengths and is centered around ~740 nm. The shape and concentration dependence of this long-wavelength ECL signal is not indicative of emission from an excimer or aggregate, but rather is suggests that a new emissive species is formed from the bpy-BODIPY luminophores during the annihilation process. PMID:23980850

  14. Ligand Binding in the Extracellular Vestibule of the Neurotransmitter Transporter Homologue LeuT.

    Science.gov (United States)

    Grouleff, Julie; Koldsø, Heidi; Miao, Yinglong; Schiøtt, Birgit

    2017-03-15

    The human monoamine transporters (MATs) facilitate the reuptake of monoamine neurotransmitters from the synaptic cleft. MATs are linked to a number of neurological diseases and are the targets of both therapeutic and illicit drugs. Until recently, no high-resolution structures of the human MATs existed, and therefore, studies of this transporter family have relied on investigations of the homologues bacterial transporters such as the leucine transporter LeuT, which has been crystallized in several conformational states. A two-substrate transport mechanism has been suggested for this transporter family, which entails that high-affinity binding of a second substrate in an extracellular site is necessary for the substrate in the central binding site to be transported. Compelling evidence for this mechanism has been presented, however, a number of equally compelling accounts suggest that the transporters function through a mechanism involving only a single substrate and a single high-affinity site. To shed light on this apparent contradiction, we have performed extensive molecular dynamics simulations of LeuT in the outward-occluded conformation with either one or two substrates bound to the transporter. We have also calculated the substrate binding affinity in each of the two proposed binding sites through rigorous free energy simulations. Results show that substrate binding is unstable in the extracellular vestibule and the substrate binding affinity within the suggested extracellular site is very low (0.2 and 3.3 M for the two dominant binding modes) compared to the central substrate binding site (14 nM). This suggests that for LeuT in the outward-occluded conformation only a single high-affinity substrate binding site exists.

  15. Neurophysiological Evidence That Musical Training Influences the Recruitment of Right Hemispheric Homologues for Speech Perception

    Directory of Open Access Journals (Sweden)

    McNeel Gordon Jantzen

    2014-03-01

    Full Text Available Musicians have a more accurate temporal and tonal representation of auditory stimuli than their non-musician counterparts (Kraus & Chandrasekaran, 2010; Parbery-Clark, Skoe, & Kraus, 2009; Zendel & Alain, 2008; Musacchia, Sams, Skoe, & Kraus, 2007. Musicians who are adept at the production and perception of music are also more sensitive to key acoustic features of speech such as voice onset timing and pitch. Together, these data suggest that musical training may enhance the processing of acoustic information for speech sounds. In the current study, we sought to provide neural evidence that musicians process speech and music in a similar way. We hypothesized that for musicians, right hemisphere areas traditionally associated with music are also engaged for the processing of speech sounds. In contrast we predicted that in non-musicians processing of speech sounds would be localized to traditional left hemisphere language areas. Speech stimuli differing in voice onset time was presented using a dichotic listening paradigm. Subjects either indicated aural location for a specified speech sound or identified a specific speech sound from a directed aural location. Musical training effects and organization of acoustic features were reflected by activity in source generators of the P50. This included greater activation of right middle temporal gyrus (MTG and superior temporal gyrus (STG in musicians. The findings demonstrate recruitment of right hemisphere in musicians for discriminating speech sounds and a putative broadening of their language network. Musicians appear to have an increased sensitivity to acoustic features and enhanced selective attention to temporal features of speech that is facilitated by musical training and supported, in part, by right hemisphere homologues of established speech processing regions of the brain.

  16. Phenotypic characterization of OmpX, an Ail homologue of Yersinia pestis KIM.

    Science.gov (United States)

    Kolodziejek, Anna M; Sinclair, Dylan J; Seo, Keun S; Schnider, Darren R; Deobald, Claudia F; Rohde, Harold N; Viall, Austin K; Minnich, Scott S; Hovde, Carolyn J; Minnich, Scott A; Bohach, Gregory A

    2007-09-01

    The goal of this study was to characterize the Yersinia pestis KIM OmpX protein. Yersinia spp. provide a model for studying several virulence processes including attachment to, and internalization by, host cells. For Yersinia enterocolitica and Yersinia pseudotuberculosis, Ail, YadA and Inv, have been implicated in these processes. In Y. pestis, YadA and Inv are inactivated. Genomic analysis of two Y. pestis strains revealed four loci with sequence homology to Ail. One of these genes, designated y1324 in the Y. pestis KIM database, encodes a protein designated OmpX. The mature protein has a predicted molecular mass of 17.47 kDa, shares approximately 70 % sequence identity with Y. enterocolitica Ail, and has an identical homologue, designated Ail, in the Y. pestis CO92 database. The present study compared the Y. pestis KIM6(+) parental strain with a mutant derivative having an engineered disruption of the OmpX structural gene. The parental strain (and a merodiploid control strain) expressed OmpX at 28 and 37 degrees C, and the protein was detectable throughout all phases of growth. OmpX was required for efficient adherence to, and internalization by, cultured HEp-2 cell monolayers and conferred resistance to the bactericidal effect of human serum. Deletion of ompX resulted in a significantly reduced autoaggregation phenotype and loss of pellicle formation in vitro. These results suggest that Y. pestis OmpX shares functional homology with Y. enterocolitica Ail in adherence, internalization into epithelial cells and serum resistance.

  17. Determination of homologues of quaternary ammonium surfactants by capillary electrophoresis using indirect UV detection.

    Science.gov (United States)

    Liu, Hsueh-Ying; Ding, Wang-Hsien

    2004-02-06

    This investigation describes the simultaneous separation of two major non-chromophoric quaternary ammonium surfactants, alkyltrimethyl- and dialkyldimethylammonium compounds (ATMACs and DADMACs, respectively), by capillary electrophoresis (CE) using indirect UV detection. The most effective separation conditions was 10 mM phosphate buffer with 57.5% tetrahydrofuran and 3 mM sodium dodecyl sulfate (SDS) at pH 4.3, and the sample hydrodynamic injection of up to 20 s at 1 psi (approximately 60 nl), and an applied voltage of 25 kV (1 psi = 6.9 kPa). Specially, the selection of an appropriate chromophore and an internal standard (I.S.) to improve the peak identification and quantitation was systematically investigated. Decylbenzyldimethyl ammonium chloride (C10-BDMA+C-) as a chromophore with 3 mM sodium dodecyl sulfate provided the best detectability for all homologues. The reproducibility of the migration time and quantitative analysis can be improved by using tetraoctyl ammonium ion as an internal standard, giving the relative standard deviation (R.S.D.) less than 0.8% for the relative migration times, and 2.5-5.5% for the relative peak areas. A good linearity of CE analysis was obtained in the range of 1.0-20 microg/ml with r2 values of above 0.999. The analysis of cationic surfactants in commercial products of hair conditioners and fabric softeners was also performed. Electrospray mass spectrometric method was applied to evaluate the CE method, and the compatible results were obtained.

  18. Fungal phytopathogens encode functional homologues of plant rapid alkalinization factor (RALF) peptides.

    Science.gov (United States)

    Thynne, Elisha; Saur, Isabel M L; Simbaqueba, Jaime; Ogilvie, Huw A; Gonzalez-Cendales, Yvonne; Mead, Oliver; Taranto, Adam; Catanzariti, Ann-Maree; McDonald, Megan C; Schwessinger, Benjamin; Jones, David A; Rathjen, John P; Solomon, Peter S

    2016-06-13

    In this article, we describe the presence of genes encoding close homologues of an endogenous plant peptide, rapid alkalinization factor (RALF), within the genomes of 26 species of phytopathogenic fungi. Members of the RALF family are key growth factors in plants, and the sequence of the RALF active region is well conserved between plant and fungal proteins. RALF1-like sequences were observed in most cases; however, RALF27-like sequences were present in the Sphaerulina musiva and Septoria populicola genomes. These two species are pathogens of poplar and, interestingly, the closest relative to their respective RALF genes is a poplar RALF27-like sequence. RALF peptides control cellular expansion during plant development, but were originally defined on the basis of their ability to induce rapid alkalinization in tobacco cell cultures. To test whether the fungal RALF peptides were biologically active in plants, we synthesized RALF peptides corresponding to those encoded by two sequenced genomes of the tomato pathogen Fusarium oxysporum f. sp. lycopersici. One of these peptides inhibited the growth of tomato seedlings and elicited responses in tomato and Nicotiana benthamiana typical of endogenous plant RALF peptides (reactive oxygen species burst, induced alkalinization and mitogen-activated protein kinase activation). Gene expression analysis confirmed that a RALF-encoding gene in F. oxysporum f. sp. lycopersici was expressed during infection on tomato. However, a subsequent reverse genetics approach revealed that the RALF peptide was not required by F. oxysporum f. sp. lycopersici for infection on tomato roots. This study has demonstrated the presence of functionally active RALF peptides encoded within phytopathogens that harbour an as yet undetermined role in plant-pathogen interactions.

  19. Phagosome maturation in unicellular eukaryote Paramecium: the presence of RILP, Rab7 and LAMP-2 homologues

    Directory of Open Access Journals (Sweden)

    E Wyroba

    2009-08-01

    Full Text Available Phagosome maturation is a complex process enabling degradation of internalised particles. Our data obtained at the gene, protein and cellular level indicate that the set of components involved in this process and known up to now in mammalian cells is functioning in unicellular eukaryote. Rab7-interacting partners: homologues of its effector RILP (Rab-interacting lysosomal protein and LAMP-2 (lysosomal membrane protein 2 as well as a7 subunit of the 26S proteasome were revealed in Paramecium phagolysosomal compartment. We identified the gene/transcript fragments encoding RILP-related proteins (RILP1 and RILP2 in Paramecium by PCR/RT-PCR and sequencing. The deduced amino acid sequences of RILP1 and RILP2 show 60.5% and 58.3% similarity, respectively, to the region involved in regulating of lysosomal morphology and dynein-dynactin recruitment of human RILP. RILP colocalised with Rab7 in Paramecium lysosomes and at phagolysosomal membrane during phagocytosis of both the latex beads and bacteria. In the same compartment LAMP-2 was present and its expression during latex internalisation was 2.5-fold higher than in the control when P2 protein fractions (100 000 x g of equal load were quantified by immunoblotting. LAMP-2 crossreacting polypeptide of ~106 kDa was glycosylated as shown by fluorescent and Western analysis of the same blot preceded by PNGase F treatment. The a7 subunit of 26S proteasome was detected close to the phagosomal membrane in the small vesicles, in some of which it colocalised with Rab7. Immunoblotting confirmed presence of RILPrelated polypeptide and a7 subunit of 26S proteasome in Paramecium protein fractions. These results suggest that Rab7, RILP and LAMP-2 may be involved in phagosome maturation in Paramecium.

  20. A transglutaminase homologue as a condensation catalyst in antibiotic assembly lines.

    Science.gov (United States)

    Fortin, Pascal D; Walsh, Christopher T; Magarvey, Nathan A

    2007-08-16

    The unrelenting emergence of antibiotic-resistant bacterial pathogens demands the investigation of antibiotics with new modes of action. The pseudopeptide antibiotic andrimid is a nanomolar inhibitor of the bacterial acetyl-CoA carboxylase that catalyses the first committed step in prokaryotic fatty acid biosynthesis. Recently, the andrimid (adm) biosynthetic gene cluster was isolated and heterologously expressed in Escherichia coli. This establishes a heterologous biological host in which to rapidly probe features of andrimid formation and to use biosynthetic engineering to make unnatural variants of this important and promising new class of antibiotics. Bioinformatic analysis of the adm cluster revealed a dissociated biosynthetic assembly system lacking canonical amide synthases between the first three carrier protein domains. Here we report that AdmF, a transglutaminase (TGase) homologue, catalyses the formation of the first amide bond, an N-acyl-beta-peptide link, in andrimid biosynthesis. Hence, AdmF is a newly discovered biosynthetic enzyme that acts as a stand-alone amide synthase between protein-bound, thiotemplated substrates in an antibiotic enzymatic assembly line. TGases (enzyme class (EC) 2.3.2.13) normally catalyse the cross-linking of (poly)peptides by creating isopeptidic bonds between the gamma-carboxamide group of a glutamine side chain of one protein and various amine donors, including lysine side chains. To the best of our knowledge, the present study constitutes the first report of a TGase-like enzyme recruited for the assembly of an antibiotic. Moreover, genome mining using the AdmF sequence yielded additional TGases in unassigned natural product biosynthetic pathways. With many more microbial genomes being sequenced, such a strategy could potentially unearth biosynthetic pathways producing new classes of antibiotics.

  1. Validating tyrosinase homologue melA as a photoacoustic reporter gene for imaging Escherichia coli

    Science.gov (United States)

    Paproski, Robert J.; Li, Yan; Barber, Quinn; Lewis, John D.; Campbell, Robert E.; Zemp, Roger

    2015-10-01

    To understand the pathogenic processes for infectious bacteria, appropriate research tools are required for replicating and characterizing infections. Fluorescence and bioluminescence imaging have primarily been used to image infections in animal models, but optical scattering in tissue significantly limits imaging depth and resolution. Photoacoustic imaging, which has improved depth-to-resolution ratio compared to conventional optical imaging, could be useful for visualizing melA-expressing bacteria since melA is a bacterial tyrosinase homologue which produces melanin. Escherichia coli-expressing melA was visibly dark in liquid culture. When melA-expressing bacteria in tubes were imaged with a VisualSonics Vevo LAZR system, the signal-to-noise ratio of a 9× dilution sample was 55, suggesting that ˜20 bacteria cells could be detected with our system. Multispectral (680, 700, 750, 800, 850, and 900 nm) analysis of the photoacoustic signal allowed unmixing of melA-expressing bacteria from blood. To compare photoacoustic reporter gene melA (using Vevo system) with luminescent and fluorescent reporter gene Nano-lantern (using Bruker Xtreme In-Vivo system), tubes of bacteria expressing melA or Nano-lantern were submerged 10 mm in 1% Intralipid, spaced between bioluminescence and fluorescence imaging could not resolve the two tubes of Nano-lantern-expressing bacteria even when the tubes were spaced 10 mm from each other. After injecting 100-μL of melA-expressing bacteria in the back flank of a chicken embryo, photoacoustic imaging allowed visualization of melA-expressing bacteria up to 10-mm deep into the embryo. Photoacoustic signal from melA could also be separated from deoxy- and oxy-hemoglobin signal observed within the embryo and chorioallantoic membrane. Our results suggest that melA is a useful photoacoustic reporter gene for visualizing bacteria, and further work incorporating photoacoustic reporters into infectious bacterial strains is warranted.

  2. Bursaphelenchus xylophilus is killed by homologues of 2-(1-undecyloxy)-1-ethanol

    Science.gov (United States)

    Kim, Junheon; Lee, Sang-Myeong; Park, Chung Gyoo

    2016-07-01

    2-(1-Undecyloxy)-1-ethanol, monochamol, is a male-produced aggregation pheromone of the Monochamus species, which are efficient vectors of the pine wood nematode (PWN), Bursaphelenchus xylophilus, which cause devastating damage to pines worldwide. The nematicidal activity of synthetic monochamol and its homologues (ROEtOH: R = C7-C13) were investigated to find potential alternatives to the currently used PWN control agents abamectin and emamectin. Compounds with C7-C13 chain length alkyl groups exhibited 100% nematicidal activity at a concentration of 1000 mg/L. At a concentration of 100 mg/L, 2-(1-nonyloxy)-1-ethanol (C9OEtOH), 2-(1-decyloxy)-1-ethanol (C10OEtOH), 2-(1-undecyloxy)-1-ethanol (C11OEtOH), and 2-(1-dodecyloxy)-1-ethanol (C12OEtOH) showed 100% nematicidal activity, but the others showed weaker activities. C11OEtOH showed similar nematicidal activity to abamectin in terms of LD90 values, which were 13.30 and 12.53 mg/L, respectively. However, C9OEtOH, C10OEtOH, and C12OEtOH (LC90 values: 53.63, 38.18, and 46.68 mg/L, respectively) were less effective than C11OEtOH and abamectin. These results indicate that monochamol could be an effective alternative agent against PWN. The relationship of insecticidal and nematicidal activity to different carbon chain lengths in compounds is discussed.

  3. Characterization of Two 20kDa-Cement Protein (cp20k) Homologues in Amphibalanus amphitrite

    KAUST Repository

    He, Li-Sheng

    2013-05-22

    The barnacle, Amphibalanus amphitrite, is a common marine fouling organism. Understanding the mechanism of barnacle adhesion will be helpful in resolving the fouling problem. Barnacle cement is thought to play a key role in barnacle attachment. Although several adult barnacle cement proteins have been identified in Megabalanus rosa, little is known about their function in barnacle settlement. In this study, two homologous 20k-cement proteins (cp20k) in Amphibalanus amphitrite, named Bamcp20k-1 and Bamcp20k-2, were characterized. The two homologues share primary sequence structure with proteins from other species including Megabalanus rosa and Fistulobalanus albicostatus. The conserved structure included repeated Cys domains and abundant charged amino acids, such as histidine. In this study we demonstrated that Bamcp20k-1 localized at the α secretory cells in the cyprid cement gland, while Bamcp20k-2 localized to the β secretory cells. The differential localizations suggest differential regulation for secretion from the secretory cells. Both Bamcp20k-1 and Bamcp20k-2 from cyprids dissolved in PBS. However, adult Bamcp20k-2, which was dominant in the basal shell of adult barnacles, was largely insoluble in PBS. Solubility increased in the presence of the reducing reagent Dithiothreitol (DTT), suggesting that the formation of disulfide bonds plays a role in Bamcp20k-2 function. In comparison, Bamcp20k-1, which was enriched in soft tissue, could not be easily detected in the shell and base by Western blot and easily dissolved in PBS. These differential solubilities and localizations indicate that Bamcp20k-1 and Bamcp20k-2 have distinct functions in barnacle cementing. © 2013 He et al.

  4. The two PPX-GppA homologues from Mycobacterium tuberculosis have distinct biochemical activities.

    Directory of Open Access Journals (Sweden)

    Mei Y Choi

    Full Text Available Inorganic polyphosphate (poly-P, guanosine pentaphosphate (pppGpp and guanosine tetraphosphate (ppGpp are ubiquitous in bacteria. These molecules play a variety of important physiological roles associated with stress resistance, persistence, and virulence. In the bacterial pathogen Mycobacterium tuberculosis, the identities of the proteins responsible for the metabolism of polyphosphate and (pppGpp remain to be fully established. M. tuberculosis encodes two PPX-GppA homologues, Rv0496 (MTB-PPX1 and Rv1026, which share significant sequence similarity with bacterial exopolyphosphatase (PPX and guanosine pentaphosphate 5'-phosphohydrolase (GPP proteins. Here we delineate the respective biochemical activities of the Rv0496 and Rv1026 proteins and benchmark these against the activities of the PPX and GPP proteins from Escherichia coli. We demonstrate that Rv0496 functions as an exopolyphosphatase, showing a distinct preference for relatively short-chain poly-P substrates. In contrast, Rv1026 has no detectable exopolyphosphatase activities. Analogous to the E. coli PPX and GPP enzymes, the exopolyphosphatase activities of Rv0496 are inhibited by pppGpp and, to a lesser extent, by ppGpp alarmones, which are produced during the bacterial stringent response. However, neither Rv0496 nor Rv1026 have the ability to hydrolyze pppGpp to ppGpp; a reaction catalyzed by E. coli PPX and GPP. Both the Rv0496 and Rv1026 proteins have modest ATPase and to a lesser extent ADPase activities. pppGpp alarmones inhibit the ATPase activities of Rv1026 and, to a lesser extent, the ATPase activities of Rv0496. We conclude that PPX-GppA family proteins may not possess all the catalytic activities implied by their name and may play distinct biochemical roles involved in polyphosphate and (pppGpp metabolic pathways.

  5. Solid-phase synthesis and pharmacological evaluation of analogues of PhTX-12-A potent and selective nicotinic acetylcholine receptor antagonist

    DEFF Research Database (Denmark)

    Strømgaard, Kristian; Mellor, Ian R; Andersen, Kim;

    2002-01-01

    Philanthotoxin-12 (PhTX-12) is a novel potent and selective, noncompetitive antagonist of nicotinic acetylcholine receptors (nAChRs). Homologues of PhTX-12 with 7-11 methylene groups between the primary amino group and the aromatic head-group were synthesized using solid-phase methodology. In vitro...

  6. Requirements of Multiple Domains of SLI-1, a Caenorhabditis elegans Homologue of c-Cbl, and an Inhibitory Tyrosine in LET-23 in Regulating Vulval Differentiation

    Science.gov (United States)

    Yoon, Charles H.; Chang, Chieh; Hopper, Neil A.; Lesa, Giovanni M.; Sternberg, Paul W.

    2000-01-01

    SLI-1, a Caenorhabditis elegans homologue of the proto-oncogene product c-Cbl, is a negative regulator of LET-23-mediated vulval differentiation. Lack of SLI-1 activity can compensate for decreased function of the LET-23 epidermal growth factor receptor, the SEM-5 adaptor, but not the LET-60 RAS, suggesting that SLI-1 acts before RAS activation. SLI-1 and c-Cbl comprise an N-terminal region (termed SLI-1:N/Cbl-N, containing a four-helix bundle, an EF hand calcium-binding domain, and a divergent SH2 domain) followed by a RING finger domain and a proline-rich C-terminus. In a transgenic functional assay, the proline-rich C-terminal domain is not essential for sli-1(+) function. A protein lacking the SH2 and RING finger domains has no activity, but a chimeric protein with the SH2 and RING finger domains of SLI-1 replaced by the equivalent domains of c-Cbl has activity. The RING finger domain of c-Cbl has been shown recently to enhance ubiquitination of active RTKs by acting as an E3 ubiquitin–protein ligase. We find that the RING finger domain of SLI-1 is partially dispensable. Further, we identify an inhibitory tyrosine of LET-23 requiring sli-1(+) for its effects: removal of this tyrosine closely mimics the loss of sli-1 but not of another negative regulator, ark-1. Thus, we suggest that this inhibitory tyrosine mediates its effects through SLI-1, which in turn inhibits signaling upstream of LET-60 RAS in a manner not wholly dependent on the ubiquitin–ligase domain. PMID:11071924

  7. Small Molecule Agonists of the Orphan Nuclear Receptors Steroidogenic Factor-1 (SF-1, NR5A1) and Liver Receptor Homologue-1 (LRH-1, NR5A2)

    Energy Technology Data Exchange (ETDEWEB)

    Whitby, Richard J.; Stec, Jozef; Blind, Raymond D.; Dixon, Sally; Leesnitzer, Lisa M.; Orband-Miller, Lisa A.; Williams, Shawn P.; Willson, Timothy M.; Xu, Robert; Zuercher, William J.; Cai, Fang; Ingraham, Holly A. (GSKNC); (Southampton); (UCSF)

    2011-09-27

    The crystal structure of LRH-1 ligand binding domain bound to our previously reported agonist 3-(E-oct-4-en-4-yl)-1-phenylamino-2-phenyl-cis-bicyclo[3.3.0]oct-2-ene 5 is described. Two new classes of agonists in which the bridgehead anilino group from our first series was replaced with an alkoxy or 1-ethenyl group were designed, synthesized, and tested for activity in a peptide recruitment assay. Both new classes gave very active compounds, particularly against SF-1. Structure-activity studies led to excellent dual-LRH-1/SF-1 agonists (e.g., RJW100) as well as compounds selective for LRH-1 (RJW101) and SF-1 (RJW102 and RJW103). The series based on 1-ethenyl substitution was acid stable, overcoming a significant drawback of our original bridgehead anilino-substituted series. Initial studies on the regulation of gene expression in human cell lines showed excellent, reproducible activity at endogenous target genes.

  8. From arylamine N-acetyltransferase to folate-dependent acetyl CoA hydrolase: impact of folic acid on the activity of (HUMAN)NAT1 and its homologue (MOUSE)NAT2.

    Science.gov (United States)

    Laurieri, Nicola; Dairou, Julien; Egleton, James E; Stanley, Lesley A; Russell, Angela J; Dupret, Jean-Marie; Sim, Edith; Rodrigues-Lima, Fernando

    2014-01-01

    Acetyl Coenzyme A-dependent N-, O- and N,O-acetylation of aromatic amines and hydrazines by arylamine N-acetyltransferases is well characterised. Here, we describe experiments demonstrating that human arylamine N-acetyltransferase Type 1 and its murine homologue (Type 2) can also catalyse the direct hydrolysis of acetyl Coenzyme A in the presence of folate. This folate-dependent activity is exclusive to these two isoforms; no acetyl Coenzyme A hydrolysis was found when murine arylamine N-acetyltransferase Type 1 or recombinant bacterial arylamine N-acetyltransferases were incubated with folate. Proton nuclear magnetic resonance spectroscopy allowed chemical modifications occurring during the catalytic reaction to be analysed in real time, revealing that the disappearance of acetyl CH3 from acetyl Coenzyme A occurred concomitantly with the appearance of a CH3 peak corresponding to that of free acetate and suggesting that folate is not acetylated during the reaction. We propose that folate is a cofactor for this reaction and suggest it as an endogenous function of this widespread enzyme. Furthermore, in silico docking of folate within the active site of human arylamine N-acetyltransferase Type 1 suggests that folate may bind at the enzyme's active site, and facilitate acetyl Coenzyme A hydrolysis. The evidence presented in this paper adds to our growing understanding of the endogenous roles of human arylamine N-acetyltransferase Type 1 and its mouse homologue and expands the catalytic repertoire of these enzymes, demonstrating that they are by no means just xenobiotic metabolising enzymes but probably also play an important role in cellular metabolism. These data, together with the characterisation of a naphthoquinone inhibitor of folate-dependent acetyl Coenzyme A hydrolysis by human arylamine N-acetyltransferase Type 1/murine arylamine N-acetyltransferase Type 2, open up a range of future avenues of exploration, both for elucidating the developmental role of these

  9. From arylamine N-acetyltransferase to folate-dependent acetyl CoA hydrolase: impact of folic acid on the activity of (HUMANNAT1 and its homologue (MOUSENAT2.

    Directory of Open Access Journals (Sweden)

    Nicola Laurieri

    Full Text Available Acetyl Coenzyme A-dependent N-, O- and N,O-acetylation of aromatic amines and hydrazines by arylamine N-acetyltransferases is well characterised. Here, we describe experiments demonstrating that human arylamine N-acetyltransferase Type 1 and its murine homologue (Type 2 can also catalyse the direct hydrolysis of acetyl Coenzyme A in the presence of folate. This folate-dependent activity is exclusive to these two isoforms; no acetyl Coenzyme A hydrolysis was found when murine arylamine N-acetyltransferase Type 1 or recombinant bacterial arylamine N-acetyltransferases were incubated with folate. Proton nuclear magnetic resonance spectroscopy allowed chemical modifications occurring during the catalytic reaction to be analysed in real time, revealing that the disappearance of acetyl CH3 from acetyl Coenzyme A occurred concomitantly with the appearance of a CH3 peak corresponding to that of free acetate and suggesting that folate is not acetylated during the reaction. We propose that folate is a cofactor for this reaction and suggest it as an endogenous function of this widespread enzyme. Furthermore, in silico docking of folate within the active site of human arylamine N-acetyltransferase Type 1 suggests that folate may bind at the enzyme's active site, and facilitate acetyl Coenzyme A hydrolysis. The evidence presented in this paper adds to our growing understanding of the endogenous roles of human arylamine N-acetyltransferase Type 1 and its mouse homologue and expands the catalytic repertoire of these enzymes, demonstrating that they are by no means just xenobiotic metabolising enzymes but probably also play an important role in cellular metabolism. These data, together with the characterisation of a naphthoquinone inhibitor of folate-dependent acetyl Coenzyme A hydrolysis by human arylamine N-acetyltransferase Type 1/murine arylamine N-acetyltransferase Type 2, open up a range of future avenues of exploration, both for elucidating the

  10. The opiorphin gene (ProL1) and its homologues function in erectile physiology.

    Science.gov (United States)

    Tong, Yuehong; Tar, Moses; Melman, Arnold; Davies, Kelvin

    2008-09-01

    To determine if ProL1, a member of the opiorphin family of genes, can modulate erectile physiology, as it encodes a peptide which acts as a neutral endopeptidase inhibitor, other examples of which (Vcsa1, hSMR3A) modulate erectile physiology. We cloned members of the opiorphin family of genes into the same mammalian expression backbone (pVAX); 100 microg of these plasmids (pVAX-Vcsa1, -hSMR3A, -hSMR3B and -ProL1) were injected intracorporally into retired breeder rats and the affect on erectile physiology assessed visually, by histology and by measuring the intracavernous pressure (ICP) and blood pressure (BP). As a positive control, rats were treated with pVAX-hSlo (expressing the MaxiK potassium channel) and as a negative control the empty backbone plasmid was injected (pVAX). We also compared the level of expression of ProL1 in corporal tissue of patients not reporting erectile dysfunction (ED), ED associated with diabetes and ED not caused by diabetes. Gene transfer of plasmids expressing all members of the opiorphin family had a similar and significant effect on erectile physiology. At the concentration used in these experiments (100 microg) they resulted in higher resting ICP, and histological and visual analysis showed evidence of a priapic-like condition. After electrostimulation of the cavernous nerve, rats had significantly better ICP/BP than the negative control (pVAX). Gene transfer of pVAX-hSlo increased the ICP/BP ratio to a similar extent to the opiorphin homologues, but with no evidence for a priapic-like condition. Corpora cavernosa tissue samples obtained from men with ED, regardless of underlying causes, had significant down-regulation of both hSMR3A and ProL1. All members of the human opiorphin family of genes can potentially modulate erectile physiology. Both hSMR3 and ProL1 are down-regulated in the corpora of men with ED, and therefore both genes can potentially act as markers of ED.

  11. Structure, Mechanism, and Substrate Profile for Sco3058: The Closest Bacterial Homologue to Human Renal Dipeptidase

    Energy Technology Data Exchange (ETDEWEB)

    Cummings, J.; Nguyen, T; Fedorov, A; Kolb, P; Xu, C; Fedorov, E; Shoichet, B; Barondeau, D; Almo, S; Raushel, F

    2010-01-01

    Human renal dipeptidase, an enzyme associated with glutathione metabolism and the hydrolysis of {beta}-lactams, is similar in sequence to a cluster of 400 microbial proteins currently annotated as nonspecific dipeptidases within the amidohydrolase superfamily. The closest homologue to the human renal dipeptidase from a fully sequenced microbe is Sco3058 from Streptomyces coelicolor. Dipeptide substrates of Sco3058 were identified by screening a comprehensive series of L-Xaa-L-Xaa, L-Xaa-D-Xaa, and D-Xaa-L-Xaa dipeptide libraries. The substrate specificity profile shows that Sco3058 hydrolyzes a broad range of dipeptides with a marked preference for an l-amino acid at the N-terminus and a d-amino acid at the C-terminus. The best substrate identified was L-Arg-D-Asp (k{sub cat}/K{sub m} = 7.6 x 10{sup 5} M{sup -1} s{sup -1}). The three-dimensional structure of Sco3058 was determined in the absence and presence of the inhibitors citrate and a phosphinate mimic of L-Ala-D-Asp. The enzyme folds as a ({beta}/{alpha}){sub 8} barrel, and two zinc ions are bound in the active site. Site-directed mutagenesis was used to probe the importance of specific residues that have direct interactions with the substrate analogues in the active site (Asp-22, His-150, Arg-223, and Asp-320). The solvent viscosity and kinetic effects of D{sub 2}O indicate that substrate binding is relatively sticky and that proton transfers do not occurr during the rate-limiting step. A bell-shaped pH-rate profile for k{sub cat} and k{sub cat}/K{sub m} indicated that one group needs to be deprotonated and a second group must be protonated for optimal turnover. Computational docking of high-energy intermediate forms of L/D-Ala-L/D-Ala to the three-dimensional structure of Sco3058 identified the structural determinants for the stereochemical preferences for substrate binding and turnover.

  12. Validating tyrosinase homologue melA as a photoacoustic reporter gene for imaging Escherichia coli.

    Science.gov (United States)

    Paproski, Robert J; Li, Yan; Barber, Quinn; Lewis, John D; Campbell, Robert E; Zemp, Roger

    2015-10-01

    To understand the pathogenic processes for infectious bacteria, appropriate research tools are required for replicating and characterizing infections. Fluorescence and bioluminescence imaging have primarily been used to image infections in animal models, but optical scattering in tissue significantly limits imaging depth and resolution. Photoacoustic imaging, which has improved depth-to-resolution ratio compared to conventional optical imaging, could be useful for visualizing melA-expressing bacteria since melA is a bacterial tyrosinase homologue which produces melanin. Escherichia coli-expressing melA was visibly dark in liquid culture. When melA-expressing bacteria in tubes were imaged with a VisualSonics Vevo LAZR system, the signal-to-noise ratio of a 9×dilution sample was 55, suggesting that ∼20 bacteria cells could be detected with our system. Multispectral (680, 700, 750, 800, 850, and 900 nm) analysis of the photoacoustic signal allowed unmixing of melA-expressing bacteria from blood. To compare photoacoustic reporter gene melA (using Vevo system) with luminescent and fluorescent reporter gene Nano-lantern (using Bruker Xtreme In-Vivo system), tubes of bacteria expressing melA or Nano-lantern were submerged 10 mm in 1% Intralipid, spaced between Photoacoustic imaging could resolve the two tubes of melA-expressing bacteria even when the tubes were less than 1 mm from each other, while bioluminescence and fluorescence imaging could not resolve the two tubes of Nano-lantern-expressing bacteria even when the tubes were spaced 10 mm from each other. After injecting 100-μL of melA-expressing bacteria in the back flank of a chicken embryo, photoacoustic imaging allowed visualization of melA-expressing bacteria up to 10-mm deep into the embryo. Photoacoustic signal from melA could also be separated from deoxy- and oxy-hemoglobin signal observed within the embryo and chorioallantoic membrane. Our results suggest that melA is a useful photoacoustic reporter gene

  13. Substrate-modulated gating dynamics in a Na+-coupled neurotransmitter transporter homologue.

    Science.gov (United States)

    Zhao, Yongfang; Terry, Daniel S; Shi, Lei; Quick, Matthias; Weinstein, Harel; Blanchard, Scott C; Javitch, Jonathan A

    2011-06-02

    Neurotransmitter/Na(+) symporters (NSSs) terminate neuronal signalling by recapturing neurotransmitter released into the synapse in a co-transport (symport) mechanism driven by the Na(+) electrochemical gradient. NSSs for dopamine, noradrenaline and serotonin are targeted by the psychostimulants cocaine and amphetamine, as well as by antidepressants. The crystal structure of LeuT, a prokaryotic NSS homologue, revealed an occluded conformation in which a leucine (Leu) and two Na(+) are bound deep within the protein. This structure has been the basis for extensive structural and computational exploration of the functional mechanisms of proteins with a LeuT-like fold. Subsequently, an 'outward-open' conformation was determined in the presence of the inhibitor tryptophan, and the Na(+)-dependent formation of a dynamic outward-facing intermediate was identified using electron paramagnetic resonance spectroscopy. In addition, single-molecule fluorescence resonance energy transfer imaging has been used to reveal reversible transitions to an inward-open LeuT conformation, which involve the movement of transmembrane helix TM1a away from the transmembrane helical bundle. We investigated how substrate binding is coupled to structural transitions in LeuT during Na(+)-coupled transport. Here we report a process whereby substrate binding from the extracellular side of LeuT facilitates intracellular gate opening and substrate release at the intracellular face of the protein. In the presence of alanine, a substrate that is transported ∼10-fold faster than leucine, we observed alanine-induced dynamics in the intracellular gate region of LeuT that directly correlate with transport efficiency. Collectively, our data reveal functionally relevant and previously hidden aspects of the NSS transport mechanism that emphasize the functional importance of a second substrate (S2) binding site within the extracellular vestibule. Substrate binding in this S2 site appears to act cooperatively

  14. Synthesis and pharmacological evaluation of conformationally constrained glutamic acid higher homologues

    DEFF Research Database (Denmark)

    Tamborini, Lucia; Cullia, Gregorio; Nielsen, Birgitte;

    2016-01-01

    Homologation of glutamic acid chain together with conformational constraint is a commonly used strategy to achieve selectivity towards different types of glutamate receptors. In the present work, starting from two potent and selective unnatural amino acids previously developed by us, we investiga...

  15. Improved detection of remote homologues using cascade PSI-BLAST: influence of neighbouring protein families on sequence coverage.

    Directory of Open Access Journals (Sweden)

    Swati Kaushik

    Full Text Available BACKGROUND: Development of sensitive sequence search procedures for the detection of distant relationships between proteins at superfamily/fold level is still a big challenge. The intermediate sequence search approach is the most frequently employed manner of identifying remote homologues effectively. In this study, examination of serine proteases of prolyl oligopeptidase, rhomboid and subtilisin protein families were carried out using plant serine proteases as queries from two genomes including A. thaliana and O. sativa and 13 other families of unrelated folds to identify the distant homologues which could not be obtained using PSI-BLAST. METHODOLOGY/PRINCIPAL FINDINGS: We have proposed to start with multiple queries of classical serine protease members to identify remote homologues in families, using a rigorous approach like Cascade PSI-BLAST. We found that classical sequence based approaches, like PSI-BLAST, showed very low sequence coverage in identifying plant serine proteases. The algorithm was applied on enriched sequence database of homologous domains and we obtained overall average coverage of 88% at family, 77% at superfamily or fold level along with specificity of ~100% and Mathew's correlation coefficient of 0.91. Similar approach was also implemented on 13 other protein families representing every structural class in SCOP database. Further investigation with statistical tests, like jackknifing, helped us to better understand the influence of neighbouring protein families. CONCLUSIONS/SIGNIFICANCE: Our study suggests that employment of multiple queries of a family for the Cascade PSI-BLAST searches is useful for predicting distant relationships effectively even at superfamily level. We have proposed a generalized strategy to cover all the distant members of a particular family using multiple query sequences. Our findings reveal that prior selection of sequences as query and the presence of neighbouring families can be important for

  16. A GTP-binding protein of Mycoplasma hominis: a small sized homolog to the signal recognition particle receptor FtsY

    DEFF Research Database (Denmark)

    Ladefoged, Søren; Christiansen, Gunna

    1997-01-01

    A protein homologous to the Escherichia coli FtsY which in turn has characteristics in common with the alpha-subunit of the eukaryotic signal recognition particle receptor (SRalpha) in the membrane of the endoplasmic reticulum, was identified in Mycoplasma hominis and its encoding DNA sequenced......-anchoring fragment. Comparison of sequenced SRalpha homologue indicates that M. hominis together with Bacillus subtilis comprise a distinct cluster of similar small SRP receptors....

  17. A C-type lectin collaborates with a CD45 phosphatase homologue to facilitate West Nile virus infection of mosquitoes

    OpenAIRE

    Cheng, Gong; Cox, Jonathan; Wang, Penghua; Krishnan, Manoj N; Dai, Jianfeng; Qian, Feng; Anderson, John F.; Fikrig, Erol

    2010-01-01

    West Nile virus (WNV) is the most common arthropod-borne flavivirus in the United States; however, the vector ligand(s) that participate in infection are not known. We now show that an Aedes aegypti C-type lectin, mosGCTL-1, is induced by WNV, interacts with WNV in a calcium-dependent manner, and facilitates infection in vivo and in vitro. A mosquito homologue of human CD45 in A. aegypti, designated mosPTP-1, recruits mosGCTL-1 to enable viral attachment to cells, and to enhance viral entry. ...

  18. Prenylated Indolediketopiperazine Peroxides and Related Homologues from the Marine Sediment-Derived Fungus Penicillium brefeldianum SD-273

    Directory of Open Access Journals (Sweden)

    Chun-Yan An

    2014-01-01

    Full Text Available Three new indolediketopiperazine peroxides, namely, 24-hydroxyverruculogen (1, 26-hydroxyverruculogen (2, and 13-O-prenyl-26-hydroxyverruculogen (3, along with four known homologues (4–7, were isolated and identified from the culture extract of the marine sediment-derived fungus Penicillium brefeldianum SD-273. Their structures were determined based on the extensive spectroscopic analysis and compound 1 was confirmed by X-ray crystallographic analysis. The absolute configuration of compounds 1–3 was determined using chiral HPLC analysis of their acidic hydrolysates. Each of the isolated compounds was evaluated for antibacterial and cytotoxic activity as well as brine shrimp (Artemia salina lethality.

  19. Crystal structure of myotoxin-II: a myotoxic phospholipase A{sub 2} - homologue from Bothrops moojeni venom

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, W.F.; Ward, R.J.; Lombardi, F.R.; Arni, R.K. [UNESP, Sao Jose do Rio Preto, SP (Brazil). Inst. de Biociencias, Letras e Ciencias Exatas; Soares, A.M.; Giglio, J.R. [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Escola de Medicina; Fontes, M.R.M. [UNESP, Botucatu, SP (Brazil). Inst. Biofisica

    1997-12-31

    Full text. Phospho lipases A2 (PLA{sub 2}; E C 3.1.1.4, phosphatides s n-2 acyl hydrolases) hydrolysis the s n-2 ester bond of phospholipids showing enhanced activity at lamellar or membrane surfaces. Intracellular PLA{sub 2} s are involved at phospholipid metabolism and signal transduction, whereas extracellular PLA{sub 2} s are found in mammalian pancreatic juices, the venoms of snakes, lizards and insects. Based on their high primary sequence similarity, extracellular PLA{sub 2} s are separated into Classes I, II and III. Class II PLA{sub 2} s are found in snake venoms of Crotalidae an Viperidae species, and include the sub-family of Lys PLA{sub 2} s homologue. he coordination of the Ca{sup 2+} ion in the PLA{sub 2} calcium-binding loop includes and aspartate at position 49. In the catalytically active PLA{sub 2} s, this calcium ion plays a critical role in the stabilization of the tetrahedral transition state intermediate in the catalytic mechanism. The conservative substitution Asp49-Lys results in a decreased calcium affinity with a concomitant loss of catalytic activity, and naturally occurring PLA{sub 2} s-homologues showing the same substitution are catalytically inactive. However, the Lys PLA{sub 2} s possess cytolytic and myotoxic activities and furthermore retain the ability to disrupt the integrity of both plasma membranes and model lipid layers by a ca{sup 2+}-independent mechanism for which there is no evidence of lipid hydrolysis. Lys 49 PLA{sub 2} homologues have been isolated from several Bothrops spp. venoms including B. moojeni. Therefore, in order to improve our understanding of the molecular basis of the myotoxic and Ca{sup 2+} independent membrane damaging activities we have determined the crystal structure of MjTX-II, a Lys 49 homologue from the venom of B. moojeni. The model presented has been determined at 2.0 A resolution and refined to a crystallographic residual of 19.7% (R{sub f}ree=28.1%). (author)

  20. An Arabidopsis ctpA homologue is involved in the repair of photosystem Ⅱ under high light

    Institute of Scientific and Technical Information of China (English)

    YIN ShuMing; SUN XuWu; ZHANG LiXin

    2008-01-01

    A T-DNA insertion mutant AtctpA 1 was identified to study the physiological roles of a carboxyl-terminal processing protease (CtpA) homologue in Arabidopsis. Under normal growth conditions, disruption of AtctpA1 did not result in any apparent alterations in growth rate and thylakoid membrane protein components. However the mutant plants exhibited increased sensitivity to high irradiance. Degradation of PSII reaction center protein D1 was accelerated in the mutant during photoinhibition. These results demostrated that AtctpA1 was required for efficient repair of PSII in Arabidopsis under high irradiance.

  1. A masquerade-like serine proteinase homologue is necessary for phenoloxidase activity in the coleopteran insect, Holotrichia diomphalia larvae.

    Science.gov (United States)

    Kwon, T H; Kim, M S; Choi, H W; Joo, C H; Cho, M Y; Lee, B L

    2000-10-01

    Previously, we reported the molecular cloning of cDNA for the prophenoloxidase activating factor-I (PPAF-I) that encoded a member of the serine proteinase group with a disulfide-knotted motif at the N-terminus and a trypsin-like catalytic domain at the C-terminus [Lee, S.Y., Cho, M.Y., Hyun, J.H., Lee, K.M., Homma, K.I., Natori, S. , Kawabata, S.I., Iwanaga, S. & Lee, B.L. (1998) Eur. J. Biochem. 257, 615-621]. PPAF-I is directly involved in the activation of pro-phenoloxidase (pro-PO) by limited proteolysis and the overall structure is highly similar to that of Drosophila easter serine protease, an essential serine protease zymogen for pattern formation in normal embryonic development. Here, we report purification and molecular cloning of cDNA for another 45-kDa novel PPAF from the hemocyte lysate of Holotrichia diomphalia larvae. The gene encodes a serine proteinase homologue consisting of 415 amino-acid residues with a molecular mass of 45 256 Da. The overall structure of the 45-kDa protein is similar to that of masquerade, a serine proteinase homologue expressed during embryogenesis, larval, and pupal development in Drosophila melanogaster. The 45-kDa protein contained a trypsin-like serine proteinase domain at the C-terminus, except for the substitution of Ser of the active site triad to Gly and had a disulfide-knotted domain at the N-terminus. A highly similar 45-kDa serine proteinase homologue was also cloned from the larval cDNA library of another coleopteran, Tenebrio molitor. By in vitro reconstitution experiments, we found that the purified 45-kDa serine proteinase homologue, the purified active PPAF-I and the purified pro-PO were necessary for expressing phenoloxidase activity in the Holotrichia pro-PO system. However, incubation of pro-PO with either PPAF-I or 45-kDa protein, no phenoloxidase activity was observed. Interestingly, when the 45-kDa protein was incubated with PPAF-I and pro-PO in the absence, but not in the presence of Ca2+, the 45-k

  2. Reversed-phase ion-pair high-performance liquid chromatography assay of polyprenyl diphosphate oligomer homologues.

    Science.gov (United States)

    Kozlov, Vyacheslav V; Danilov, Leonid L

    2016-02-01

    A reversed-phase ion-pair high-performance liquid chromatography procedure was developed for the separation of polyprenyl diphosphate oligomer homologues obtained chemically from plant polyprenols. Tetrabutylammonium phosphate was used as the ion-pair reagent, and the dependence of the separation quality on pH of ion-pair reagent was investigated for the first time. The procedure is applicable for the control of commercial available polyprenyl monophosphates (the active components of veterinary drugs Phosprenyl and Gamapren) for the possible presence of polyprenyl diphosphate byproducts. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Protein 4.1, a component of the erythrocyte membrane skeleton and its related homologue proteins forming the protein 4.1/FERM superfamily.

    Directory of Open Access Journals (Sweden)

    Aleksander F Sikorski

    2007-01-01

    Full Text Available The review is focused on the domain structure and function of protein 4.1, one of the proteins belonging to the membrane skeleton. The protein 4.1 of the red blood cells (4.1R is a multifunctional protein that localizes to the membrane skeleton and stabilizes erythrocyte shape and membrane mechanical properties, such as deformability and stability, via lateral interactions with spectrin, actin, glycophorin C and protein p55. Protein 4.1 binding is modulated through the action of kinases and/or calmodulin-Ca2+. Non-erythroid cells express the 4.1R homologues: 4.1G (general type, 4.1B (brain type, and 4.1N (neuron type, and the whole group belongs to the protein 4.1 superfamily, which is characterized by the presence of a highly conserved FERM domain at the N-terminus of the molecule. Proteins 4.1R, 4.1G, 4.1N and 4.1B are encoded by different genes. Most of the 4.1 superfamily proteins also contain an actin-binding domain. To date, more than 40 members have been identified. They can be divided into five groups: protein 4.1 molecules, ERM proteins, talin-related molecules, protein tyrosine phosphatase (PTPH proteins and NBL4 proteins. We have focused our attention on the main, well known representatives of 4.1 superfamily and tried to choose the proteins which are close to 4.1R or which have distinct functions. 4.1 family proteins are not just linkers between the plasma membrane and membrane skeleton; they also play an important role in various processes. Some, such as focal adhesion kinase (FAK, non-receptor tyrosine kinase that localizes to focal adhesions in adherent cells, play the role in cell adhesion. The other members control or take part in tumor suppression, regulation of cell cycle progression, inhibition of cell proliferation, downstream signaling of the glutamate receptors, and establishment of cell polarity; some are also involved in cell proliferation, cell motility, and/or cell-to-cell communication.

  4. Gene targeting by RNAi-mediated knockdown of potent DNA ligase IV homologue in the cellulase-producing fungus Talaromyces cellulolyticus.

    Science.gov (United States)

    Hayata, Koutarou; Asada, Seiya; Fujii, Tatsuya; Inoue, Hiroyuki; Ishikawa, Kazuhiko; Sawayama, Shigeki

    2014-11-01

    The genome of the cellulase-producing fungus Talaromyces cellulolyticus (formerly Acremonium cellulolyticus) was screened for a potent DNA ligase IV gene (ligD homologue). Homologous recombination efficiency in T. cellulolyticus is very low. Therefore, suppression of a non-homologous end-joining system was attempted to enable specific gene knockouts for molecular breeding. The transcript levels of ligD homologue were 0.037 of those of the parental YP-4 strain in the Li20 transformant carrying the RNAi construct targeting the ligD homologue. Transformation of the hairpin-type RNAi vector into T. cellulolyticus could be useful in fungal gene knockdown experiments. Cellulase production and protein secretion were similar in the parental YP-4 strain and the Li20 transformant. Knockout transformation of ligD homologue using the Li20 transformant led to 23.1 % double crossover gene targeting. Our results suggest that the potent DNA ligase IV gene of T. cellulolyticus is related to non-homologous end joining and that the knockdown of the ligD homologue is useful in gene targeting.

  5. Somatostatin receptors

    DEFF Research Database (Denmark)

    Møller, Lars Neisig; Stidsen, Carsten Enggaard; Hartmann, Bolette

    2003-01-01

    therefore been acknowledged to be a third endogenous ligand at SRIF receptors. This review goes through mechanisms of signal transduction, pharmacology, and anatomical distribution of SRIF receptors. Structurally, SRIF receptors belong to the superfamily of G protein-coupled (GPC) receptors, sharing....... The generation of knock-out (KO) mice, intended as a means to define the contributions made by individual receptor subtypes, necessarily marks but an approximation. Furthermore, we must now take into account the stunning complexity of receptor co-operation indicated by the observation of receptor homo......-peptides, receptor agonists and antagonists. Relatively long half lives, as compared to those of the endogenous ligands, have been paramount from the outset. Motivated by theoretical puzzles or the shortcomings of present-day diagnostics and therapy, investigators have also aimed to produce subtype...

  6. Purification, crystallization and preliminary crystallographic analysis of archaeal 6-pyruvoyl tetrahydrobiopterin synthase homologue PH0634 from Pyrococcus horikoshii OT3

    Energy Technology Data Exchange (ETDEWEB)

    Bagautdinov, Bagautdin [Advanced Protein Crystallography Research Group, RIKEN SPring-8 Center, Harima Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Sugahara, Mitsuaki [Structural Biophysics Laboratory, RIKEN SPring-8 Center, Harima Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Kunishima, Naoki, E-mail: kunisima@spring8.or.jp [Advanced Protein Crystallography Research Group, RIKEN SPring-8 Center, Harima Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)

    2007-01-01

    An archaeal 6-pyruvoyl tetrahydrobiopterin synthase homologue from P. horikoshii OT3 was overexpressed as native and selenomethionine-substituted protein, purified and crystallized. The native and selenomethionine-derivative crystals are isomorphous and diffract X-rays to 2.1 and 2.9 Å resolution, respectively. 6-Pyruvoyl tetrahydrobiopterin synthase (PTPS) catalyses the conversion of dihydroneopterin triphosphate to 6-pyruvoyl tetrahydropterin, the second of the three enzymatic steps in the synthesis of tetrahydrobiopterin from GTP. PH0634, a 13.51 kDa archaeal PTPS homologue from Pyrococcus horikoshii OT3, was overexpressed as native and selenomethionine-substituted protein and the purified protein was crystallized by the oil-microbatch method at 295 K. X-ray diffraction data were collected to 2.1 Å resolution from the native crystal using synchrotron radiation at 100 K. The crystal belongs to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 35.83, b = 95.71, c = 105.65 Å. Threefold noncrystallographic symmetry was identified from self-rotation calculations. Assuming the presence of a trimer in the asymmetric unit, the solvent content is 45% (V{sub M} = 2.24 Å{sup 3} Da{sup −1}). The selenomethionine-substituted crystal is isomorphous to the native crystal and diffracts X-rays to 2.9 Å.

  7. Biodegradation of diesel fuel by a microbial consortium in the presence of 1-alkoxymethyl-2-methyl-5-hydroxypyridinium chloride homologues

    DEFF Research Database (Denmark)

    Chrzanowski, L; Stasiewicz, M; Owsianiak, Mikolaj

    2009-01-01

    Fast development of ionic liquids as gaining more and more attention valuable chemicals will undoubtedly lead to environmental pollution. New formulations and application of ionic liquids may result in contamination in the presence of hydrophobic compounds, such as petroleum mixtures. We hypothes......Fast development of ionic liquids as gaining more and more attention valuable chemicals will undoubtedly lead to environmental pollution. New formulations and application of ionic liquids may result in contamination in the presence of hydrophobic compounds, such as petroleum mixtures. We...... hypothesize that in the presence of diesel fuel low-water-soluble ionic liquids may become more toxic to hydrocarbon-degrading microorganisms. In this study the influence of 1-alkoxymethyl-2-methyl-5-hydroxypyridinium chloride homologues (side-chain length from C-3 to C-18) on biodegradation of diesel fuel...... by a bacterial consortium was investigated. Whereas test performed for the consortium cultivated on disodium succinate showed that toxicity of the investigated ionic liquids decreased with increase in side-chain length, only higher homologues (C-8-C-18) caused a decrease in diesel fuel biodegradation...

  8. A 1.4-Mb interval RH map of horse chromosome 17 provides detailed comparison with human and mouse homologues.

    Science.gov (United States)

    Lee, Eun-Joon; Raudsepp, Terje; Kata, Srinivas R; Adelson, David; Womack, James E; Skow, Loren C; Chowdhary, Bhanu P

    2004-02-01

    Comparative genomics has served as a backbone for the rapid development of gene maps in domesticated animals. The integration of this approach with radiation hybrid (RH) analysis provides one of the most direct ways to obtain physically ordered comparative maps across evolutionarily diverged species. We herein report the development of a detailed RH and comparative map for horse chromosome 17 (ECA17). With markers distributed at an average interval of every 1.4 Mb, the map is currently the most informative among the equine chromosomes. It comprises 75 markers (56 genes and 19 microsatellites), of which 50 gene specific and 5 microsatellite markers were generated in this study and typed to our 5000-rad horse x hamster whole genome RH panel. The markers are dispersed over six RH linkage groups and span 825 cR(5000). The map is among the most comprehensive whole chromosome comparative maps currently available for domesticated animals. It finely aligns ECA17 to human and mouse homologues (HSA13 and MMU1, 3, 5, 8, and 14, respectively) and homologues in other domesticated animals. Comparisons provide insight into their relative organization and help to identify evolutionarily conserved segments. The new ECA17 map will serve as a template for the development of clusters of BAC contigs in regions containing genes of interest. Sequencing of these regions will help to initiate studies aimed at understanding the molecular mechanisms for various diseases and inherited disorders in horse as well as human.

  9. Determination of the fate of alcohol ethoxylate homologues in a laboratory continuous activated-sludge unit study.

    Science.gov (United States)

    Wind, T; Stephenson, R J; Eadsforth, C V; Sherren, A; Toy, R

    2006-05-01

    Environmental monitoring indicates that the distribution of alcohol ethoxylate (AE) homologues in wastewater treatment plant (WWTP) effluents differs from the distribution in commercial AE products, with a relative higher proportion of fatty alcohol (AOH, which is AE with zero ethoxylation). To determine the contribution of AE-derived AOH to the total concentration of AE and AOH in WWTP effluents, we conducted a laboratory continuous activated-sludge study (CAS). This consisted of a test unit fed with AE-amended synthetic sewage and a control unit fed with only synthetic sewage to avoid AE contamination from the feed. The removal efficiencies of some 114 AE homologues were determined by the application of a specific and sensitive analytical method. The extent of the removal of AE ranged from 99.70% for C18 compounds to > 99.98% for C12-16. Relatively high-AOH concentrations were observed in the effluents from blank and test units. By building the concentration difference from the test minus the control unit, the AE in the CAS effluent originating from AE in the influent was determined. Thus, it could be shown that AOH represented only 19% of the total AE (EO0-18) in the CAS, while monitoring in 29 WWTP effluents (European, Canadian, and US) revealed in total a mean AOH fraction of 55% (5-82%) of the total AE (EO0-18). This shows that only a small fraction of AOH in WWTP effluents originates from AE entering the WWTP.

  10. Dimerization and heme binding are conserved in amphibian and starfish homologues of the microRNA processing protein DGCR8.

    Directory of Open Access Journals (Sweden)

    Rachel Senturia

    Full Text Available Human DiGeorge Critical Region 8 (DGCR8 is an essential microRNA (miRNA processing factor that is activated via direct interaction with Fe(III heme. In order for DGCR8 to bind heme, it must dimerize using a dimerization domain embedded within its heme-binding domain (HBD. We previously reported a crystal structure of the dimerization domain from human DGCR8, which demonstrated how dimerization results in the formation of a surface important for association with heme. Here, in an attempt to crystallize the HBD, we search for DGCR8 homologues and show that DGCR8 from Patiria miniata (bat star also binds heme. The extinction coefficients (ε of DGCR8-heme complexes are determined; these values are useful for biochemical analyses and allow us to estimate the heme occupancy of DGCR8 proteins. Additionally, we present the crystal structure of the Xenopus laevis dimerization domain. The structure is very similar to that of human DGCR8. Our results indicate that dimerization and heme binding are evolutionarily conserved properties of DGCR8 homologues not only in vertebrates, but also in at least some invertebrates.

  11. The Drosophila melanogaster Apaf-1 homologue ARK is required for most, but not all, programmed cell death.

    Science.gov (United States)

    Mills, Kathryn; Daish, Tasman; Harvey, Kieran F; Pfleger, Cathie M; Hariharan, Iswar K; Kumar, Sharad

    2006-03-13

    The Apaf-1 protein is essential for cytochrome c-mediated caspase-9 activation in the intrinsic mammalian pathway of apoptosis. Although Apaf-1 is the only known mammalian homologue of the Caenorhabditis elegans CED-4 protein, the deficiency of apaf-1 in cells or in mice results in a limited cell survival phenotype, suggesting that alternative mechanisms of caspase activation and apoptosis exist in mammals. In Drosophila melanogaster, the only Apaf-1/CED-4 homologue, ARK, is required for the activation of the caspase-9/CED-3-like caspase DRONC. Using specific mutants that are deficient for ark function, we demonstrate that ARK is essential for most programmed cell death (PCD) during D. melanogaster development, as well as for radiation-induced apoptosis. ark mutant embryos have extra cells, and tissues such as brain lobes and wing discs are enlarged. These tissues from ark mutant larvae lack detectable PCD. During metamorphosis, larval salivary gland removal was severely delayed in ark mutants. However, PCD occurred normally in the larval midgut, suggesting that ARK-independent cell death pathways also exist in D. melanogaster.

  12. A WD40-repeat gene from Malus x domestica is a functional homologue of Arabidopsis thaliana TRANSPARENT TESTA GLABRA1.

    Science.gov (United States)

    Brueggemann, Julian; Weisshaar, Bernd; Sagasser, Martin

    2010-03-01

    The WD40 repeat protein TRANSPARENT TESTA GLABRA1 (TTG1) is involved in a multitude of developmental and biochemical reactions in Arabidopsis thaliana such as the production of seed coat colour and mucilage, pigmentation by anthocyanins as well as the formation of trichomes and root hairs. In this study, a putative TTG1 homologue was isolated from apple (Malus x domestica Borkh.) showing 80.2% identity to A. thaliana TTG1 on nucleotide and 90.7% similarity on amino acid level. The MdTTG1 candidate was able to activate the AtBAN promoter in cooperation with the A. thaliana transcription factors TT2 and TT8 in A. thaliana protoplasts. This indicates that the encoded protein can be integrated into the complex that activates BAN in A. thaliana, and that a similar complex might also be present in apple. When transformed into ttg1 mutants of A. thaliana, the apple sequence was able to restore trichome growth, anthocyanin production in young seedlings as well as proanthocyanidin production in seeds. Additionally, roots of complemented mutant plants showed root hair formation resembling wild type. These results show that the studied apple WD40 gene is a functional homologue of AtTTG1 and we refer to this gene as MdTTG1.

  13. In situ hydrothermal growth of metal-organic framework 199 films on stainless steel fibers for solid-phase microextraction of gaseous benzene homologues.

    Science.gov (United States)

    Cui, Xiao-Yan; Gu, Zhi-Yuan; Jiang, Dong-Qing; Li, Yan; Wang, He-Fang; Yan, Xiu-Ping

    2009-12-01

    Metal-organic frameworks (MOFs) have received great attention due to their fascinating structures and intriguing potential applications in various fields. Herein, we report the first example of the utilization of MOFs for solid-phase microextraction (SPME). MOF-199 with unique pores and open metal sites (Lewis acid sites) was employed as the coating for SPME fiber to extract volatile and harmful benzene homologues. The SPME fiber was fabricated by in situ hydrothermal growth of thin MOF-199 films on etched stainless steel wire. The MOF-199-coated fiber not only offered large enhancement factors from 19,613 (benzene) to 110,860 (p-xylene), but also exhibited wide linearity with 3 orders of magnitude for the tested benzene homologues. The limits of detection for the benzene homologues were 8.3-23.3 ng L(-1). The relative standard deviation (RSD) for six replicate extractions using one SPME fiber ranged from 2.0% to 7.7%. The fiber-to-fiber reproducibility for three parallel prepared fibers was 3.5%-9.4% (RSD). Indoor air samples were analyzed for the benzene homologues using the SPME with the MOF-199-coated fiber in combination with gas chromatography-flame ionization detection. The recoveries for the spiked benzene homologues in the collected indoor air samples were in the range of 87%-106%. The high affinity of the MOF-199-coated fiber to benzene homologues resulted from the combined effects of the large surface area and the unique porous structure of the MOF-199, the pi-pi interactions of the aromatic rings of the analytes with the framework 1,3,5-benzenetricarboxylic acid molecules, and the pi-complexation of the electron-rich analytes to the Lewis acid sites in the pores of MOF-199.

  14. Synthesis and pharmacological evaluation of conformationally constrained glutamic acid higher homologues.

    Science.gov (United States)

    Tamborini, Lucia; Cullia, Gregorio; Nielsen, Birgitte; De Micheli, Carlo; Conti, Paola; Pinto, Andrea

    2016-11-15

    Homologation of glutamic acid chain together with conformational constraint is a commonly used strategy to achieve selectivity towards different types of glutamate receptors. In the present work, starting from two potent and selective unnatural amino acids previously developed by us, we investigated the effects on the activity/selectivity profile produced by a further increase in the distance between the amino acidic moiety and the distal carboxylate group. Interestingly, the insertion of an aromatic ring as a spacer produced a low micromolar affinity NMDA ligand that might represent a lead for the development of a new class of NMDA antagonists. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Conversion of functional specificity in Qb-SNARE VTI1 homologues of Arabidopsis.

    Science.gov (United States)

    Niihama, Mitsuru; Uemura, Tomohiro; Saito, Chieko; Nakano, Akihiko; Sato, Masa H; Tasaka, Masao; Morita, Miyo Terao

    2005-03-29

    In higher multicellular eukaryotes, highly specialized membrane structures or membrane trafficking events are required for supporting various physiological functions. SNAREs (soluble NSF attachment protein receptors) play an important role in specific membrane fusions. These protein receptors are assigned to subgroubs (Qa-, Qb-, Qc-, and R-SNARE) according to their specific SNARE structural motif. A specific set of Qa-, Qb-, and Qc-SNAREs, located on the target membrane, interact with R-SNARE on the vesicle to form a tight complex, leading to membrane fusion. The zig-1 mutant of Arabidopsis lacking Qb-SNARE VTI11 shows little shoot gravitropism and abnormal stem morphology. VTI11 and its homolog VTI12 exhibit partially overlapping but distinct intracellular localization and have different biological functions in plants. Little is known about how SNAREs are targeted to specific organelles, even though their functions and specific localization are closely linked. Here, we report that a novel mutation in VTI12 (zip1) was found as a dominant suppressor of zig-1. The zip1 mutation gave VTI12 the ability to function as VTI11 by changing both the specificity of SNARE complex formation and its intracellular localization. One amino acid substitution drastically altered VTI12, allowing it to suppress abnormalities of higher order physiological functions such as gravitropism and morphology. The zip1 mutation may be an indication of the flexibility in plant cell function afforded by gene duplication, particularly among the VTI11 genes and their recently diverged orthologs.

  16. Novel neutrophil inhibitory factor homologue in the buccal gland secretion of Lampetra japonica.

    Science.gov (United States)

    Xue, Zhuang; Bai, Jie; Sun, Jing; Wu, Yu; Yu, Shui Yan; Guo, Ren Yong; Liu, Xin; Li, Qing Wei

    2011-07-01

    Abstract To identify the functional gene fragment, a neutrophil inhibitory factor (NIF) like protein was found in the buccal gland of Lampetra japonica, suggesting that this related lamprey protein represents a novel class of integrin receptor antagonists. The recombinant Lampetra japonica-NIF like (rLj-NIF) was identified by SDS-PAGE and purified by using His·Bind affinity chromatography. Effect of rLj-NIF on neutrophil migration suggested that rLj-NIF can act as a neutrophil inhibitory factor. Besides that, oxidative burst activity of neutriphil was tested by flow cytometry using dihydrorhodamine (DHR123) as a fluorogenic substrate, and the data suggested that the mean fluorescence intensity significantly decreased compared with positive controls (pNIF could also prevent the binding of β2 integrins to the surface of PMN and its FITC-labeled monoclonal antibodies (pNIF like protein is secreted by the stage of the parasite at the site of attachment. rLj-NIF plays an essential role in physiological reaction of neutrophil by a novel class of β2 integrin receptor antagonists. The activity of immunosuppressant of L. japonica-NIF could have potential medicinal value in anti-inflammation and therapy of autoimmune diseases.

  17. Snipper, an Eri1 homologue, affects histone mRNA abundance and is crucial for normal Drosophila melanogaster development.

    Science.gov (United States)

    Alexiadis, Anastasios; Delidakis, Christos; Kalantidis, Kriton

    2017-07-01

    The conserved 3'-5' RNA exonuclease ERI1 is implicated in RNA interference inhibition, 5.8S rRNA maturation and histone mRNA maturation and turnover. The single ERI1 homologue in Drosophila melanogaster Snipper (Snp) is a 3'-5' exonuclease, but its in vivo function remains elusive. Here, we report Snp requirement for normal Drosophila development, since its perturbation leads to larval arrest and tissue-specific downregulation results in abnormal tissue development. Additionally, Snp directly interacts with histone mRNA, and its depletion results in drastic reduction in histone transcript levels. We propose that Snp protects the 3'-ends of histone mRNAs and upon its absence, histone transcripts are readily degraded. This in turn may lead to cell cycle delay or arrest, causing growth arrest and developmental perturbations. © 2017 Federation of European Biochemical Societies.

  18. Investigation of evaporation characteristics of polonium and its lighter homologues selenium and tellurium from liquid Pb-Bi-eutecticum

    CERN Document Server

    Neuhausen, J; Eichler, B

    2004-01-01

    The evaporation behaviour of polonium and its lighter homologues selenium and tellurium dissolved in liquid Pb-Bi-eutecticum (LBE) has been studied at various temperatures in the range from 482 K up to 1330 K under Ar/H2 and Ar/H2O-atmospheres using γ-ray spectroscopy. Polonium release in the temperature range of interest for technical applications is slow. Within short term (1h) experiments measurable amounts of polonium are evaporated only at temperatures above 973 K. Long term experiments reveal that a slow evaporation of polonium occurs at temperatures around 873 K resulting in a fractional polonium loss of the melt around 1% per day. Evaporation rates of selenium and tellurium are smaller than those of polonium. The presence of H2O does not enhance the evaporation within the error limits of our experiments. The thermodynamics and possible reaction pathways involved in polonium release from LBE are discussed.

  19. The contributions of protein disulfide isomerase and its homologues to oxidative protein folding in the yeast endoplasmic reticulum

    DEFF Research Database (Denmark)

    Xiao, Ruoyu; Wilkinson, Bonney; Solovyov, Anton

    2004-01-01

    In vitro, protein disulfide isomerase (Pdi1p) introduces disulfides into proteins (oxidase activity) and provides quality control by catalyzing the rearrangement of incorrect disulfides (isomerase activity). Protein disulfide isomerase (PDI) is an essential protein in Saccharomyces cerevisiae......, but the contributions of the catalytic activities of PDI to oxidative protein folding in the endoplasmic reticulum (ER) are unclear. Using variants of Pdi1p with impaired oxidase or isomerase activity, we show that isomerase-deficient mutants of PDI support wild-type growth even in a strain in which all of the PDI...... homologues of the yeast ER have been deleted. Although the oxidase activity of PDI is sufficient for wild-type growth, pulse-chase experiments monitoring the maturation of carboxypeptidase Y reveal that oxidative folding is greatly compromised in mutants that are defective in isomerase activity. Pdi1p...

  20. In mouse oocytes the mitochondrion-originated germinal body-like structures accumulate mouse Vasa homologue (MVH) protein.

    Science.gov (United States)

    Reunov, Arkadiy A; Reunova, Yulia A

    2015-08-01

    Mouse Vasa homologue (MVH) antibodies were applied to mouse Graafian oocytes to clarify if mitochondrion-originated germinal body-like structures, described previously by conventional electron microscopy, were associated with the germ plasm. It was found that both the mitochondrion-like structures with cristae and the germinal body-like structures that lacked any signs of cristae were labelled specifically by the anti-MVH antibody. Moreover, some granules were MVH-positive ultrastructural hybrids of the mitochondria and germinal body-like structures, the presence of which clearly supported the idea of a mitochondrial origin for the germinal body-like structures. This finding is the first evidence that mitochondrion-originated germinal body-like granules represent mouse germ plasm.

  1. 14-3-3 proteins act as intracellular receptors for rice Hd3a florigen.

    Science.gov (United States)

    Taoka, Ken-ichiro; Ohki, Izuru; Tsuji, Hiroyuki; Furuita, Kyoko; Hayashi, Kokoro; Yanase, Tomoko; Yamaguchi, Midori; Nakashima, Chika; Purwestri, Yekti Asih; Tamaki, Shojiro; Ogaki, Yuka; Shimada, Chihiro; Nakagawa, Atsushi; Kojima, Chojiro; Shimamoto, Ko

    2011-07-31

    'Florigen' was proposed 75 years ago to be synthesized in the leaf and transported to the shoot apex, where it induces flowering. Only recently have genetic and biochemical studies established that florigen is encoded by FLOWERING LOCUS T (FT), a gene that is universally conserved in higher plants. Nonetheless, the exact function of florigen during floral induction remains poorly understood and receptors for florigen have not been identified. Here we show that the rice FT homologue Hd3a interacts with 14-3-3 proteins in the apical cells of shoots, yielding a complex that translocates to the nucleus and binds to the Oryza sativa (Os)FD1 transcription factor, a rice homologue of Arabidopsis thaliana FD. The resultant ternary 'florigen activation complex' (FAC) induces transcription of OsMADS15, a homologue of A. thaliana APETALA1 (AP1), which leads to flowering. We have determined the 2.4 Å crystal structure of rice FAC, which provides a mechanistic basis for florigen function in flowering. Our results indicate that 14-3-3 proteins act as intracellular receptors for florigen in shoot apical cells, and offer new approaches to manipulate flowering in various crops and trees.

  2. Identification and characterisation of the angiotensin converting enzyme-3 (ACE3 gene: a novel mammalian homologue of ACE

    Directory of Open Access Journals (Sweden)

    Phelan Anne

    2007-06-01

    Full Text Available Abstract Background Mammalian angiotensin converting enzyme (ACE plays a key role in blood pressure regulation. Although multiple ACE-like proteins exist in non-mammalian organisms, to date only one other ACE homologue, ACE2, has been identified in mammals. Results Here we report the identification and characterisation of the gene encoding a third homologue of ACE, termed ACE3, in several mammalian genomes. The ACE3 gene is located on the same chromosome downstream of the ACE gene. Multiple sequence alignment and molecular modelling have been employed to characterise the predicted ACE3 protein. In mouse, rat, cow and dog, the predicted protein has mutations in some of the critical residues involved in catalysis, including the catalytic Glu in the HEXXH zinc binding motif which is Gln, and ESTs or reverse-transcription PCR indicate that the gene is expressed. In humans, the predicted ACE3 protein has an intact HEXXH motif, but there are other deletions and insertions in the gene and no ESTs have been identified. Conclusion In the genomes of several mammalian species there is a gene that encodes a novel, single domain ACE-like protein, ACE3. In mouse, rat, cow and dog ACE3, the catalytic Glu is replaced by Gln in the putative zinc binding motif, indicating that in these species ACE3 would lack catalytic activity as a zinc metalloprotease. In humans, no evidence was found that the ACE3 gene is expressed and the presence of deletions and insertions in the sequence indicate that ACE3 is a pseudogene.

  3. Homologue of Protein Kinase Mζ Maintains Context Aversive Memory and Underlying Long-Term Facilitation in Terrestrial Snail Helix.

    Directory of Open Access Journals (Sweden)

    Pavel M. Balaban

    2015-06-01

    Full Text Available It has been shown that a variety of long-term memories in different regions of the brain and in different species are quickly erased by local inhibition of PKMζ. Using antibodies to mammalian PKMζ, we describe in the present study the localization of immunoreactive molecules in the nervous system of the terrestrial snail Helix lucorum. Presence of a homologue of PKMζ was confirmed with transcriptomics. We have demonstrated in behavioral experiments that contextual fear memory disappeared under a blockade of PKMζ with a selective peptide blocker of PKMζ (ZIP, but not with scrambled ZIP. If ZIP was combined with a reminder (20 min in noxious context, no impairment of the long-term contextual memory was observed. In electrophysiological experiments we investigated whether PKMζ takes part in the maintenance of long-term facilitation (LTF in the neural circuit mediating tentacle withdrawal. LTF of excitatory synaptic inputs to premotor interneurons was induced by high-frequency nerve stimulation combined with serotonin bath applications and lasted at least four hours. We found that bath application of 2x10-6 M ZIP at the 90th min after the tetanization reduced the EPSP amplitude to the non-tetanized EPSP values. Applications of the scrambled ZIP peptide at a similar time and concentration didn't affect the EPSP amplitudes. In order to test whether effects of ZIP are specific to the synapses, we performed experiments with LTF of somatic membrane responses to local glutamate applications. It was shown earlier that serotonin application in such an artificial synapse condition elicits LTF of responses to glutamate. It was found that ZIP had no effect on LTF in these conditions, which may be explained by the very low concentration of PKMζ molecules in somata of these identified neurons, as evidenced by immunochemistry. Obtained results suggest that the Helix homologue of PKMζ might be involved in post-induction maintenance of long-term changes in

  4. Plasmodium falciparum Bloom homologue, a nucleocytoplasmic protein, translocates in 3' to 5' direction and is essential for parasite growth.

    Science.gov (United States)

    Rahman, Farhana; Tarique, Mohammed; Tuteja, Renu

    2016-05-01

    Malaria caused by Plasmodium, particularly Plasmodium falciparum, is the most serious and widespread parasitic disease of humans. RecQ helicase family members are essential in homologous recombination-based error-free DNA repair processes in all domains of life. RecQ helicases present in each organism differ and several homologues have been identified in various multicellular organisms. These proteins are involved in various pathways of DNA metabolism by providing duplex unwinding function. Five members of RecQ family are present in Homo sapiens but P. falciparum contains only two members of this family. Here we report the detailed biochemical and functional characterization of the Bloom (Blm) homologue (PfBlm) from P. falciparum 3D7 strain. Purified PfBlm exhibits ATPase and 3' to 5' direction specific DNA helicase activity. The calculated average reaction rate of ATPase was ~13 pmol of ATP hydrolyzed/min/pmol of enzyme. The immunofluorescence assay results show that PfBlm is expressed in all the stages of intraerythrocytic development of the P. falciparum 3D7 strain. In some stages of development in addition to nucleus PfBlm also localizes in the cytoplasm. The gene disruption studies of PfBlm by dsRNA showed that it is required for the ex-vivo intraerythrocytic development of the parasite P. falciparum 3D7 strain. The dsRNA mediated inhibition of parasite growth suggests that a variety of pathways are affected resulting in curtailing of the parasite growth. This study will be helpful in unravelling the basic mechanism of DNA transaction in the malaria parasite and additionally it may provide leads to understand the parasite specific characteristics of this protein.

  5. Human low molecular weight neurofilament (NFL) mRNA interacts with a predicted p190RhoGEF homologue (RGNEF) in humans.

    Science.gov (United States)

    Volkening, Kathryn; Leystra-Lantz, Cheryl; Strong, Michael J

    2010-01-01

    In the mouse, p190RhoGEF is a low molecular weight neurofilament (NFL) mRNA stability factor that is involved in NF aggregate formation in neurons. A human homologue of this protein has not been described. Our objective was to identify a human homologue of p190RhoGEF, and to determine its interaction with human NFL mRNA. We used sequence homology searches to predict a human homologue (RGNEF), and RT-PCR to determine the expression of mRNA in ALS and neuropathologically normal control tissues. Gel shift assays determined the interaction of RGNEF with human NFL mRNA in vitro, while IP-RT-PCR and gel shift assays were used to confirm the interaction in tissue lysates. We determined that RGNEF is a human homologue of p190RhoGEF, and that its RNA is expressed in both brain and spinal cord. While RGNEF and NFL mRNA interact directly in vitro, interestingly they only appear to interact in ALS lysates and not in controls. These data add another player to the family of NFL mRNA stability regulators, and raise the intriguing possibility that the mechanism by which p190RhoGEF contributes to murine neuronal NF aggregate formation may be important to human ALS NF aggregate formation.

  6. Allele mining in the gene pool of wild Solanum species for homologues of late blight resistance gene RB/Rpi-blb1

    Science.gov (United States)

    Solanum bulbocastanum comprising a CC-NBS-LRR gene RB/Rpi-blb1 confers broad-spectrum resistance to Phytophthora infestans and is currently employed in potato breeding for durable late blight (LB) resistance. Genomes of several Solanum species were reported to contain RB homologues with confirmed b...

  7. Genetic analysis of the two zebrafish patched homologues identifies novel roles for the hedgehog signaling pathway

    Directory of Open Access Journals (Sweden)

    Groot Evelyn

    2008-02-01

    Full Text Available Abstract Background Aberrant activation of the Hedgehog (Hh signaling pathway in different organisms has shown the importance of this family of morphogens during development. Genetic screens in zebrafish have assigned specific roles for Hh in proliferation, differentiation and patterning, but mainly as a result of a loss of its activity. We attempted to fully activate the Hh pathway by removing both receptors for the Hh proteins, called Patched1 and 2, which are functioning as negative regulators in this pathway. Results Here we describe a splice-donor mutation in Ptc1, called ptc1hu1602, which in a homozygous state results in a subtle eye and somite phenotype. Since we recently positionally cloned a ptc2 mutant, a ptc1;ptc2 double mutant was generated, showing severely increased levels of ptc1, gli1 and nkx2.2a, confirming an aberrant activation of Hh signaling. As a consequence, a number of phenotypes were observed that have not been reported previously using Shh mRNA overexpression. Somites of ptc1;ptc2 double mutants do not express anteroposterior polarity markers, however initial segmentation of the somites itself is not affected. This is the first evidence that segmentation and anterior/posterior (A/P patterning of the somites are genetically uncoupled processes. Furthermore, a novel negative function of Hh signaling is observed in the induction of the fin field, acting well before any of the previously reported function of Shh in fin formation and in a way that is different from the proposed early role of Gli3 in limb/fin bud patterning. Conclusion The generation and characterization of the ptc1;ptc2 double mutant assigned novel and unexpected functions to the Hh signaling pathway. Additionally, these mutants will provide a useful system to further investigate the consequences of constitutively activated Hh signaling during vertebrate development.

  8. Phorbol-induced surface expression of NR2A subunit homologues in HEK293 cells

    Institute of Scientific and Technical Information of China (English)

    Chan-ying ZHENG; Xiu-juan YANG; Zhan-yan FU; Jian-hong LUO

    2006-01-01

    Aim: N-methyl-D-aspartate receptors (NMDAR) are heteromeric complexes primarily assembled from NR1 and NR2 subunits. In normal conditions, NR2 sub-units assemble into homodimers in the endoplasmic reticulum (ER). These homodimers remain in the ER until they coassemble with NR1 dimers and are trafficked to the cell surface. However, it still remains unclear whether functional homomeric NMDAR exist in physiological or pathological conditions. Methods: We transfected GFP-NR2A alone into HEK293 cells, treated the cells with PKC activator 12-myristate-13 acetate (PMA), and then detected surface NR2A sub-units with a live cell immunostaining method. We also used a series of NR2A mutants with a partial deletion of its C-terminus to identify the regions that are involved in the PMA-mediated surface expression of NR2A subunits. Results: NR2A subunits were expressed on the cell membrane after incubation with PMA (200 nmol/L,30 min), although no functional NMDA channels were detected after PMA-induced membrane trafficking. Immunostaining with an ER marker also revealed that NR2A subunits were exported from the ER after PMA treatment. Furthermore, the deletion of amino acids between 1149-1347 or 1354-1464 of NR2A inhibited PMA-induced surface expression of NR2A subunits. Conclusion: First, our data suggests that PMA treatment can induce the surface expression of homomeric NR2A subunits. Furthermore, this process is probably mediated by the NR2A C-terminal region between positions 1149 and 1464.

  9. Down Syndrome Cognitive Phenotypes Modeled in Mice Trisomic for All HSA 21 Homologues

    Science.gov (United States)

    Belichenko, Pavel V.; Kleschevnikov, Alexander M.; Becker, Ann; Wagner, Grant E.; Lysenko, Larisa V.; Yu, Y. Eugene; Mobley, William C.

    2015-01-01

    Down syndrome (DS), trisomy for chromosome 21, is the most common genetic cause of intellectual disability. The genomic regions on human chromosome 21 (HSA21) are syntenically conserved with regions on mouse chromosomes 10, 16, and 17 (Mmu10, Mmu16, and Mmu17). Recently, we created a genetic model of DS which carries engineered duplications of all three mouse syntenic regions homologous to HSA21. This ‘triple trisomic’ or TTS model thus represents the most complete and accurate murine model currently available for experimental studies of genotype-phenotype relationships in DS. Here we extended our initial studies of TTS mice. Locomotor activity, stereotypic and repetitive behavior, anxiety, working memory, long-term memory, and synaptic plasticity in the dentate gyrus were examined in the TTS and wild-type (WT) control mice. Changes in locomotor activity were most remarkable for a significant increase in ambulatory time and a reduction in average velocity of TTS mice. No changes were detected in repetitive and stereotypic behavior and in measures of anxiety. Working memory showed no changes when tested in Y-maze, but deficiency in a more challenging T-maze test was detected. Furthermore, long-term object recognition memory was significantly reduced in the TTS mice. These changes were accompanied by deficient long-term potentiation in the dentate gyrus, which was restored to the WT levels following blockade of GABAA receptors with picrotoxin (100 μM). TTS mice thus demonstrated a number of phenotypes characteristic of DS and may serve as a new standard by which to evaluate and direct findings in other less complete models of DS. PMID:26230397

  10. The daf-4 gene encodes a bone morphogenetic protein receptor controlling C. elegans dauer larva development.

    Science.gov (United States)

    Estevez, M; Attisano, L; Wrana, J L; Albert, P S; Massagué, J; Riddle, D L

    1993-10-14

    The bone morphogenetic protein (BMP) family is a conserved group of signalling molecules within the transforming growth factor-beta (TGF-beta) superfamily. This group, including the Drosophila decapentaplegic (dpp) protein and the mammalian BMPs, mediates cellular interactions and tissue differentiation during development. Here we show that a homologue of human BMPs controls a developmental switch in the life cycle of the free-living soil nematode Caenorhabditis elegans. Starvation and overcrowding induce C. elegans to form a developmentally arrested, third-stage dauer larva. The daf-4 gene, which acts to inhibit dauer larva formation and promote growth, encodes a receptor protein kinase similar to the daf-1, activin and TGF-beta receptor serine/threonine kinases. When expressed in monkey COS cells, the daf-4 receptor binds human BMP-2 and BMP-4. The daf-4 receptor is the first to be identified for any growth factor in the BMP family.

  11. The leukemia associated nuclear corepressor ETO homologue genes MTG16 and MTGR1 are regulated differently in hematopoietic cells

    Directory of Open Access Journals (Sweden)

    Ajore Ram

    2012-03-01

    Full Text Available Abstract Background MTG16, MTGR1 and ETO are nuclear transcriptional corepressors of the human ETO protein family. MTG16 is implicated in hematopoietic development and in controlling erythropoiesis/megakaryopoiesis. Furthermore, ETO homologue genes are 3'participants in leukemia fusions generated by chromosomal translocations responsible of hematopoietic dysregulation. We tried to identify structural and functional promoter elements of MTG16 and MTGR1 genes in order to find associations between their regulation and hematopoiesis. Results 5' deletion examinations and luciferase reporter gene studies indicated that a 492 bp sequence upstream of the transcription start site is essential for transcriptional activity by the MTG16 promoter. The TATA- and CCAAT-less promoter with a GC box close to the start site showed strong reporter activity when examined in erythroid/megakaryocytic cells. Mutation of an evolutionary conserved GATA -301 consensus binding site repressed promoter function. Furthermore, results from in vitro antibody-enhanced electrophoretic mobility shift assay and in vivo chromatin immunoprecipitation indicated binding of GATA-1 to the GATA -301 site. A role of GATA-1 was also supported by transfection of small interfering RNA, which diminished MTG16 expression. Furthermore, expression of the transcription factor HERP2, which represses GATA-1, produced strong inhibition of the MTG16 promoter reporter consistent with a role of GATA-1 in transcriptional activation. The TATA-less and CCAAT-less MTGR1 promoter retained most of the transcriptional activity within a -308 to -207 bp region with a GC-box-rich sequence containing multiple SP1 binding sites reminiscent of a housekeeping gene with constitutive expression. However, mutations of individual SP1 binding sites did not repress promoter function; multiple active SP1 binding sites may be required to safeguard constitutive MTGR1 transcriptional activity. The observed repression of MTG16

  12. Cloning of the Zygosaccharomyces bailii GAS1 homologue and effect of cell wall engineering on protein secretory phenotype

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    Dato Laura

    2010-01-01

    Full Text Available Abstract Background Zygosaccharomyces bailii is a diploid budding yeast still poorly characterized, but widely recognised as tolerant to several stresses, most of which related to industrial processes of production. Because of that, it would be very interesting to develop its ability as a cell factory. Gas1p is a β-1,3-glucanosyltransglycosylase which plays an important role in cell wall construction and in determining its permeability. Cell wall defective mutants of Saccharomyces cerevisiae and Pichia pastoris, deleted in the GAS1 gene, were reported as super-secretive. The aim of this study was the cloning and deletion of the GAS1 homologue of Z. bailii and the evaluation of its deletion on recombinant protein secretion. Results The GAS1 homologue of Z. bailii was cloned by PCR, and when expressed in a S. cerevisiae GAS1 null mutant was able to restore the parental phenotype. The respective Z. bailii Δgas1 deleted strain was obtained by targeted deletion of both alleles of the ZbGAS1 gene with deletion cassettes having flanking regions of ~400 bp. The morphological and physiological characterization of the Z. bailii null mutant resulted very similar to that of the corresponding S. cerevisiae mutant. As for S. cerevisiae, in the Z. bailii Δgas1 the total amount of protein released in the medium was significantly higher. Moreover, three different heterologous proteins were expressed and secreted in said mutant. The amount of enzymatic activity found in the medium was almost doubled in the case of the Candida rugosa lipase CRL1 and of the Yarrowia lipolytica protease XPR2, while for human IL-1β secretion disruption had no relevant effect. Conclusions The data presented confirm that the engineering of the cell wall is an effective way to improve protein secretion in yeast. They also confirmed that Z. bailii is an interesting candidate, despite the knowledge of its genome and the tools for its manipulation still need to be improved. However, as

  13. Molecular mechanism for the dual alcohol modulation of Cys-loop receptors.

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    Samuel Murail

    Full Text Available Cys-loop receptors constitute a superfamily of pentameric ligand-gated ion channels (pLGICs, including receptors for acetylcholine, serotonin, glycine and γ-aminobutyric acid. Several bacterial homologues have been identified that are excellent models for understanding allosteric binding of alcohols and anesthetics in human Cys-loop receptors. Recently, we showed that a single point mutation on a prokaryotic homologue (GLIC could transform it from a channel weakly potentiated by ethanol into a highly ethanol-sensitive channel. Here, we have employed molecular simulations to study ethanol binding to GLIC, and to elucidate the role of the ethanol-enhancing mutation in GLIC modulation. By performing 1-µs simulations with and without ethanol on wild-type and mutated GLIC, we observed spontaneous binding in both intra-subunit and inter-subunit transmembrane cavities. In contrast to the glycine receptor GlyR, in which we previously observed ethanol binding primarily in an inter-subunit cavity, ethanol primarily occupied an intra-subunit cavity in wild-type GLIC. However, the highly ethanol-sensitive GLIC mutation significantly enhanced ethanol binding in the inter-subunit cavity. These results demonstrate dramatic effects of the F(14'A mutation on the distribution of ligands, and are consistent with a two-site model of pLGIC inhibition and potentiation.

  14. Lipoxin Receptors

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    Mario Romano

    2007-01-01

    Full Text Available Lipoxins (LXs represent a class of arachidonic acid (AA metabolites that carry potent immunoregulatory and anti-inflammatory properties, LXA4 and LXB4 being the main components of this series. LXs are generated by cooperation between 5-lipoxygenase (LO and 12- or 15-LO during cell-cell interactions or by single cell types. LX epimers at carbon 15, the 15-epi-LXs, are formed by aspirin-acetylated cyclooxygenase-2 (COX-2 in cooperation with 5-LO. 15-epi-LXA4 is also termed aspirin-triggered LX (ATL. In vivo studies with stable LX and ATL analogs have established that these eicosanoids possess potent anti-inflammatory activities. A LXA4 receptor has been cloned. It belongs to the family of chemotactic receptors and clusters with formyl peptide receptors on chromosome 19. Therefore, it was initially denominated formyl peptide receptor like 1 (FPRL1. This receptor binds with high affinity and stereoselectivity LXA4 and ATL. It also recognizes a variety of peptides, synthetic, endogenously generated, or disease associated, but with lower affinity compared to LXA4. For this reason, this receptor has been renamed ALX. This review summarizes the current knowledge on ALX expression, signaling, and potential pathophysiological role. The involvement of additional recognition sites in LX bioactions is also discussed.

  15. Assessing the role of the ASP56/CAP homologue of Dictyostelium discoideum and the requirements for subcellular localization.

    Science.gov (United States)

    Noegel, A A; Rivero, F; Albrecht, R; Janssen, K P; Köhler, J; Parent, C A; Schleicher, M

    1999-10-01

    The CAP (cyclase-associated protein) homologue of Dictyostelium discoideum is a phosphatidylinositol 4,5-bisphosphate (PIP(2)) regulated G-actin sequestering protein which is present in the cytosol and shows enrichment at plasma membrane regions. It is composed of two domains separated by a proline rich stretch. The sequestering activity has been localized to the C-terminal domain of the protein, whereas the presence of the N-terminal domain seems to be required for PIP(2)-regulation of the sequestering activity. Here we have constructed GFP-fusions of N- and C-domain and found that the N-terminal domain showed CAP-specific enrichment at the anterior and posterior ends of cells like endogenous CAP irrespective of the presence of the proline rich region. Mutant cells expressing strongly reduced levels of CAP were generated by homologous recombination. They had an altered cell morphology with very heterogeneous cell sizes and exhibited a cytokinesis defect. Growth on bacteria was normal both in suspension and on agar plates as was phagocytosis of yeast and bacteria. In suspension in axenic medium mutant cells grew more slowly and did not reach saturation densities observed for wild-type cells. This was paralleled by a reduction in fluid phase endocytosis. Development was delayed by several hours under all conditions assayed, furthermore, motile behaviour was affected.

  16. The FBXO7 homologue nutcracker and binding partner PI31 in Drosophila melanogaster models of Parkinson's disease.

    Science.gov (United States)

    Merzetti, Eric M; Dolomount, Lindsay A; Staveley, Brian E

    2017-01-01

    Parkinsonian-pyramidal syndrome (PPS) is an early onset form of Parkinson's disease (PD) that shows degeneration of the extrapyramidal region of the brain to result in a severe form of PD. The toxic protein build-up has been implicated in the onset of PPS. Protein removal is mediated by an intracellular proteasome complex: an E3 ubiquitin ligase, the targeting component, is essential for function. FBXO7 encodes the F-box component of the SCF E3 ubiquitin ligase linked to familial forms of PPS. The Drosophila melanogaster homologue nutcracker (ntc) and a binding partner, PI31, have been shown to be active in proteasome function. We show that altered expression of either ntc or PI31 in dopaminergic neurons leads to a decrease in longevity and locomotor ability, phenotypes both associated with models of PD. Furthermore, expression of ntc-RNAi in an established α-synuclein-dependent model of PD rescues the phenotypes of diminished longevity and locomotor control.

  17. Determination of vitamin K homologues by high-performance liquid chromatography with on-line photoreactor and peroxyoxalate chemiluminescence detection

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Sameh [Graduate School of Biomedical Sciences, Course of Pharmaceutical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521 (Japan); Kishikawa, Naoya [Graduate School of Biomedical Sciences, Course of Pharmaceutical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521 (Japan); Nakashima, Kenichiro [Graduate School of Biomedical Sciences, Course of Pharmaceutical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521 (Japan); Kuroda, Naotaka [Graduate School of Biomedical Sciences, Course of Pharmaceutical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521 (Japan)]. E-mail: n-kuro@nagasaki-u.ac.jp

    2007-05-22

    A sensitive and highly selective high-performance liquid chromatography (HPLC) method was developed for the determination of vitamin K homologues including phylloquinone (PK), menaquinone-4 (MK-4) and menaquinone-7 (MK-7) in human plasma using post-column peroxyoxalate chemiluminescence (PO-CL) detection following on-line ultraviolet (UV) irradiation. The method was based on ultraviolet irradiation (254 nm, 15 W) of vitamin K to produce hydrogen peroxide and a fluorescent product at the same time, which can be determined with PO-CL detection. The separation of vitamin K by HPLC was accomplished isocratically on an ODS column within 35 min. The method involves the use of 2-methyl-3-pentadecyl-1,4-naphthoquinone as an internal standard. The detection limits (signal-to-noise ratio = 3) were 32, 38 and 85 fmol for PK, MK-4 and MK-7, respectively. The recoveries of PK, MK-4 and MK-7 were greater than 82% and the inter- and intra-assay R.S.D. values were 1.9-5.4%. The sensitivity and selectivity of this method were sufficient for clinical and nutritional applications.

  18. GTP analogue inhibits polymerization and GTPase activity of the bacterial protein FtsZ without affecting its eukaryotic homologue tubulin.

    Science.gov (United States)

    Läppchen, Tilman; Hartog, Aloysius F; Pinas, Victorine A; Koomen, Gerrit-Jan; den Blaauwen, Tanneke

    2005-05-31

    The prokaryotic tubulin homologue FtsZ plays a key role in bacterial cell division. Selective inhibitors of the GTP-dependent polymerization of FtsZ are expected to result in a new class of antibacterial agents. One of the challenges is to identify compounds which do not affect the function of tubulin and various other GTPases in eukaryotic cells. We have designed a novel inhibitor of FtsZ polymerization based on the structure of the natural substrate GTP. The inhibitory activity of 8-bromoguanosine 5'-triphosphate (BrGTP) was characterized by a coupled assay, which allows simultaneous detection of the extent of polymerization (via light scattering) and GTPase activity (via release of inorganic phosphate). We found that BrGTP acts as a competitive inhibitor of both FtsZ polymerization and GTPase activity with a Ki for GTPase activity of 31.8 +/- 4.1 microM. The observation that BrGTP seems not to inhibit tubulin assembly suggests a structural difference of the GTP-binding pockets of FtsZ and tubulin.

  19. The Drosophila HP1 homologue Rhino is required for transposon silencing and piRNA production by dual strand clusters

    Science.gov (United States)

    Klattenhoff, Carla; Xi, Hualin; Li, Chengjian; Lee, Soohyun; Xu, Jia; Khurana, Jaspreet S.; Zhang, Fan; Schultz, Nadine; Koppetsch, Birgit S.; Nowosielska, Anetta; Seitz, Herve; Zamore, Phillip D.; Weng, Zhiping; Theurkauf, William E.

    2009-01-01

    Summary piRNAs silence transposons and maintain genome integrity during germ-line development. In Drosophila, transposon-rich heterochromatic clusters encode piRNAs either on both genomic strands (dual-strand clusters) or predominantly one genomic strand (uni-strand clusters). Primary piRNAs derived from these clusters are proposed to drive a ping-pong amplification cycle catalyzed by proteins that localize to the perinuclear nuage. We show that the HP1 homologue Rhino is required for nuage organization, transposon silencing, and ping-pong amplification of piRNAs. rhi mutations virtually eliminate piRNAs from the dual-strand clusters and block production of putative precursor RNAs from both strands of the major 42AB dual-strand cluster, but do not block production of transcripts or piRNAs from the uni-strand clusters. Furthermore, Rhino protein associates with the 42AB dual-strand cluster, but does not bind to uni-strand cluster 2 or flamenco. Rhino thus appears to promote transcription of dual-strand clusters, leading to production of piRNAs that drive the ping-pong amplification cycle. PMID:19732946

  20. Modeling meiotic chromosomes indicates a size dependent contribution of telomere clustering and chromosome rigidity to homologue juxtaposition.

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    Christopher A Penfold

    Full Text Available Meiosis is the cell division that halves the genetic component of diploid cells to form gametes or spores. To achieve this, meiotic cells undergo a radical spatial reorganisation of chromosomes. This reorganisation is a prerequisite for the pairing of parental homologous chromosomes and the reductional division, which halves the number of chromosomes in daughter cells. Of particular note is the change from a centromere clustered layout (Rabl configuration to a telomere clustered conformation (bouquet stage. The contribution of the bouquet structure to homologous chromosome pairing is uncertain. We have developed a new in silico model to represent the chromosomes of Saccharomyces cerevisiae in space, based on a worm-like chain model constrained by attachment to the nuclear envelope and clustering forces. We have asked how these constraints could influence chromosome layout, with particular regard to the juxtaposition of homologous chromosomes and potential nonallelic, ectopic, interactions. The data support the view that the bouquet may be sufficient to bring short chromosomes together, but the contribution to long chromosomes is less. We also find that persistence length is critical to how much influence the bouquet structure could have, both on pairing of homologues and avoiding contacts with heterologues. This work represents an important development in computer modeling of chromosomes, and suggests new explanations for why elucidating the functional significance of the bouquet by genetics has been so difficult.

  1. Purification, crystallization and preliminary crystallographic analysis of archaeal 6-pyruvoyl tetrahydrobiopterin synthase homologue PH0634 from Pyrococcus horikoshii OT3.

    Science.gov (United States)

    Bagautdinov, Bagautdin; Sugahara, Mitsuaki; Kunishima, Naoki

    2007-01-01

    6-Pyruvoyl tetrahydrobiopterin synthase (PTPS) catalyses the conversion of dihydroneopterin triphosphate to 6-pyruvoyl tetrahydropterin, the second of the three enzymatic steps in the synthesis of tetrahydrobiopterin from GTP. PH0634, a 13.51 kDa archaeal PTPS homologue from Pyrococcus horikoshii OT3, was overexpressed as native and selenomethionine-substituted protein and the purified protein was crystallized by the oil-microbatch method at 295 K. X-ray diffraction data were collected to 2.1 A resolution from the native crystal using synchrotron radiation at 100 K. The crystal belongs to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 35.83, b = 95.71, c = 105.65 A. Threefold noncrystallographic symmetry was identified from self-rotation calculations. Assuming the presence of a trimer in the asymmetric unit, the solvent content is 45% (V(M) = 2.24 A3 Da(-1)). The selenomethionine-substituted crystal is isomorphous to the native crystal and diffracts X-rays to 2.9 A.

  2. Neurospora crassa fmf-1 encodes the homologue of the Schizosaccharomyces pombe Ste11p regulator of sexual development

    Indian Academy of Sciences (India)

    Srividhya V. Iyer; Mukund Ramakrishnan; Durgadas P. Kasbekar

    2009-04-01

    The Neurospora crassa fmf-1 mutation exerts an unusual ‘perithecium-dominant’ developmental arrest; fmf-1 × fmf-1+ cross becomes arrested in perithecial development regardless of whether the mutant participates in the cross as the male or female parent. We localized fmf-1 to the LG IL genome segment between the centromere-proximal breakpoint of the chromosome segment duplication Dp(IL)39311 and the centromere. By mapping crossovers with respect to RFLP markers in this region we further localized fmf-1 to an approximately 34-kb-genome segment. Partial sequencing of this segment revealed a point mutation in the gene NCU 09387.1, a homologue of the Schizosaccharomyces pombe ste11+ regulator of sexual development. The fmf-1 mutation did not complement a NCU 09387.1 deletion mutation, and transformation with wild-type NCU 09387.1 complemented fmf-1. S. pombe Ste11 protein (Ste 11p) is a transcription factor required for sexual differentiation and for the expression of genes required for mating pheromone signalling in matP and matM cells. If FMF-1 also plays a corresponding role in mating pheromone signalling in Neurospora, then protoperithecia in an fmf-1 × fmf-1+ cross would be unable to either send or receive sexual differentiation signals and thus become arrested in development.

  3. Anion exchange behaviour of Zr, Hf, Nb, Ta and Pa as homologues of RF and Db in fluoride medium

    Energy Technology Data Exchange (ETDEWEB)

    Monroy G, F. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Trubert, D.; Brillard, L.; Hussonnois, M.; Constantinescu, O.; Le Naour, C., E-mail: fabiola.monroy@inin.gob.m [Institut de Physique Nucleaire, F-91406 Orsay, France (France)

    2010-07-01

    Studies of the chemical property of trans actinide elements are very difficult due to their short half-lives and extremely small production yields. However it is still possible to obtain considerable information about their chemical properties, such as the most stable oxidation states in aqueous solution, complexing ability, etc., comparing their behaviour with their lighter homologous in the periodic table. In order to obtain a better knowledge of the behaviour of rutherfordium, RF (element 104), dub nium, Db (element 105) in HF medium, the sorption properties of Zr, Hf, Nb, Ta an Pa, homologues of RF and Db, were studied in NH{sub 4}F/HClO{sub 4} medium in this work. Stability constants of the fluoride complexes of these elements were experimentally obtained from K{sub d} obtained at different F{sup -} and H{sup +} concentrations. The anionic complexes: [Zr(Hf)F{sub 5}]{sup -}, [Zr(Hf)F{sub 6}]{sup 2-}, [Zr(Hf)F{sub 7}]{sup 3-}, [Ta(Pa)F{sub 6}]{sup -}, [Ta(Pa)F{sub 7}]{sup 2-}, [Ta(Pa)F{sub 8}]{sup 3-}, [NbOF{sub 4}]{sup -} and [NbOF{sub 5}]{sup 2-} are present as predominant species in the HF range over investigation. (Author)

  4. Ustilago maydis Rho1 and 14-3-3 homologues participate in pathways controlling cell separation and cell polarity.

    Science.gov (United States)

    Pham, Cau D; Yu, Zhanyang; Sandrock, Björn; Bölker, Michael; Gold, Scott E; Perlin, Michael H

    2009-07-01

    Proteins of the 14-3-3 and Rho-GTPase families are functionally conserved eukaryotic proteins that participate in many important cellular processes such as signal transduction, cell cycle regulation, malignant transformation, stress response, and apoptosis. However, the exact role(s) of these proteins in these processes is not entirely understood. Using the fungal maize pathogen, Ustilago maydis, we were able to demonstrate a functional connection between Pdc1 and Rho1, the U. maydis homologues of 14-3-3epsilon and Rho1, respectively. Our experiments suggest that Pdc1 regulates viability, cytokinesis, chromosome condensation, and vacuole formation. Similarly, U. maydis Rho1 is also involved in these three essential processes and exerts an additional function during mating and filamentation. Intriguingly, yeast two-hybrid and epistasis experiments suggest that both Pdc1 and Rho1 could be constituents of the same regulatory cascade(s) controlling cell growth and filamentation in U. maydis. Overexpression of rho1 ameliorated the defects of cells depleted for Pdc1. Furthermore, we found that another small G protein, Rac1, was a suppressor of lethality for both Pdc1 and Rho1. In addition, deletion of cla4, encoding a Rac1 effector kinase, could also rescue cells with Pdc1 depleted. Inferring from these data, we propose a model for Rho1 and Pdc1 functions in U. maydis.

  5. Deletion of the fission yeast homologue of human insulinase reveals a TORC1-dependent pathway mediating resistance to proteotoxic stress.

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    Clémentine Beuzelin

    Full Text Available Insulin Degrading Enzyme (IDE is a protease conserved through evolution with a role in diabetes and Alzheimer's disease. The reason underlying its ubiquitous expression including cells lacking identified IDE substrates remains unknown. Here we show that the fission yeast IDE homologue (Iph1 modulates cellular sensitivity to endoplasmic reticulum (ER stress in a manner dependent on TORC1 (Target of Rapamycin Complex 1. Reduced sensitivity to tunicamycin was associated with a smaller number of cells undergoing apoptosis. Wild type levels of tunicamycin sensitivity were restored in iph1 null cells when the TORC1 complex was inhibited by rapamycin or by heat inactivation of the Tor2 kinase. Although Iph1 cleaved hallmark IDE substrates including insulin efficiently, its role in the ER stress response was independent of its catalytic activity since expression of inactive Iph1 restored normal sensitivity. Importantly, wild type as well as inactive human IDE complemented gene-invalidated yeast cells when expressed at the genomic locus under the control of iph1(+ promoter. These results suggest that IDE has a previously unknown function unrelated to substrate cleavage, which links sensitivity to ER stress to a pro-survival role of the TORC1 pathway.

  6. The ClpP protease homologue is required for the transmission traits and cell division of the pathogen Legionella pneumophila

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    Zhang Qin-fen

    2010-02-01

    Full Text Available Abstract Background Legionella pneumophila, the intracellular bacterial pathogen that causes Legionnaires' disease, exhibit characteristic transmission traits such as elevated stress tolerance, shortened length and virulence during the transition from the replication phase to the transmission phase. ClpP, the catalytic core of the Clp proteolytic complex, is widely involved in many cellular processes via the regulation of intracellular protein quality. Results In this study, we showed that ClpP was required for optimal growth of L. pneumophila at high temperatures and under several other stress conditions. We also observed that cells devoid of clpP exhibited cell elongation, incomplete cell division and compromised colony formation. Furthermore, we found that the clpP-deleted mutant was more resistant to sodium stress and failed to proliferate in the amoebae host Acanthamoeba castellanii. Conclusions The data present in this study illustrate that the ClpP protease homologue plays an important role in the expression of transmission traits and cell division of L. pneumophila, and further suggest a putative role of ClpP in virulence regulation.

  7. Genetic link between Cabeza, a Drosophila homologue of Fused in Sarcoma (FUS), and the EGFR signaling pathway.

    Science.gov (United States)

    Shimamura, Mai; Kyotani, Akane; Azuma, Yumiko; Yoshida, Hideki; Binh Nguyen, Thanh; Mizuta, Ikuko; Yoshida, Tomokatsu; Mizuno, Toshiki; Nakagawa, Masanori; Tokuda, Takahiko; Yamaguchi, Masamitsu

    2014-08-01

    Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease that causes progressive muscular weakness. Fused in Sarcoma (FUS) that has been identified in familial ALS is an RNA binding protein that is normally localized in the nucleus. However, its function in vivo is not fully understood. Drosophila has Cabeza (Caz) as a FUS homologue and specific knockdown of Caz in the eye imaginal disc and pupal retina using a GMR-GAL4 driver was here found to induce an abnormal morphology of the adult compound eyes, a rough eye phenotype. This was partially suppressed by expression of the apoptosis inhibitor P35. Knockdown of Caz exerted no apparent effect on differentiation of photoreceptor cells. However, immunostaining with an antibody to Cut that marks cone cells revealed fusion of these and ommatidia of pupal retinae. These results indicate that Caz knockdown induces apoptosis and also inhibits differentiation of cone cells, resulting in abnormal eye morphology in adults. Mutation in EGFR pathway-related genes, such as rhomboid-1, rhomboid-3 and mirror suppressed the rough eye phenotype induced by Caz knockdown. Moreover, the rhomboid-1 mutation rescued the fusion of cone cells and ommatidia observed in Caz knockdown flies. The results suggest that Caz negatively regulates the EGFR signaling pathway required for determination of cone cell fate in Drosophila.

  8. The Caenorhabditis elegans p120 catenin homologue, JAC-1, modulates cadherin-catenin function during epidermal morphogenesis.

    Science.gov (United States)

    Pettitt, Jonathan; Cox, Elisabeth A; Broadbent, Ian D; Flett, Aileen; Hardin, Jeff

    2003-07-07

    The cadherin-catenin complex is essential for tissue morphogenesis during animal development. In cultured mammalian cells, p120 catenin (p120ctn) is an important regulator of cadherin-catenin complex function. However, information on the role of p120ctn family members in cadherin-dependent events in vivo is limited. We have examined the role of the single Caenorhabditis elegans p120ctn homologue JAC-1 (juxtamembrane domain [JMD]-associated catenin) during epidermal morphogenesis. Similar to other p120ctn family members, JAC-1 binds the JMD of the classical cadherin HMR-1, and GFP-tagged JAC-1 localizes to adherens junctions in an HMR-1-dependent manner. Surprisingly, depleting JAC-1 expression using RNA interference (RNAi) does not result in any obvious defects in embryonic or postembryonic development. However, jac-1(RNAi) does increase the severity and penetrance of morphogenetic defects caused by a hypomorphic mutation in the hmp-1/alpha-catenin gene. In these hmp-1 mutants, jac-1 depletion causes failure of the embryo to elongate into a worm-like shape, a process that involves contraction of the epidermis. Associated with failed elongation is the detachment of actin bundles from epidermal adherens junctions and failure to maintain cadherin in adherens junctions. These results suggest that JAC-1 acts as a positive modulator of cadherin function in C. elegans.

  9. Mapping of ionomic traits in Mimulus guttatus reveals Mo and Cd QTLs that colocalize with MOT1 homologues.

    Directory of Open Access Journals (Sweden)

    David B Lowry

    Full Text Available Natural variation in the regulation of the accumulation of mineral nutrients and trace elements in plant tissues is crucial to plant metabolism, development, and survival across different habitats. Studies of the genetic basis of natural variation in nutrient metabolism have been facilitated by the development of ionomics. Ionomics is a functional genomic approach for the identification of the genes and gene networks that regulate the elemental composition, or ionome, of an organism. In this study, we evaluated the genetic basis of divergence in elemental composition between an inland annual and a coastal perennial accession of Mimulus guttatus using a recombinant inbred line (RIL mapping population. Out of 20 elements evaluated, Mo and Cd were the most divergent in accumulation between the two accessions and were highly genetically correlated in the RILs across two replicated experiments. We discovered two major quantitative trait loci (QTL for Mo accumulation, the largest of which consistently colocalized with a QTL for Cd accumulation. Interestingly, both Mo QTLs also colocalized with the two M. guttatus homologues of MOT1, the only known plant transporter to be involved in natural variation in molybdate uptake.

  10. Biological characterization of a myotoxin phosphoplipase A2 homologue purified from the venom of the snake Bothrops moojeni

    Directory of Open Access Journals (Sweden)

    MR Queiroz

    2011-01-01

    Full Text Available A myotoxin phospholipase A2 homologue, BmooMtx, was isolated from the venom of Bothrops moojeni by a combination of ion-exchange chromatography on DEAE-Sephacel column and gel filtration on Sephadex G-75. SDS-PAGE showed the enzyme to be a monomer with a molecular weight of 16,500. BmooMtx induced release of creatine kinase and morphological analyses indicated that it provoked an intense myonecrosis, with visible leukocyte infiltrate and damaged muscle cells 24 hours after injection. Anti-BmooMTx antibodies partially neutralized the myotoxic activity of BmooMtx and crude B. moojeni venom, as judged by determination of plasma creatine kinase levels and histological evaluation of skeletal muscle in mice. Anti-BmooMTx antibodies were effective in reducing the plasma creatine kinase levels of crude B. alternatus and B. leucurus venoms, evidencing immunological cross-reactivity between BmooMTx and other bothropic venoms. Intraplantar (i.pl. injection of BmooMtx (1 to 15 μg/animal caused a dose- and time-dependent hyperalgesia and edematogenic responses. Dexamethasone (0.4 mg/kg, meloxicam (2 mg/kg and promethazine (5 mg/kg markedly reduced the hyperalgesia. Our data suggest that these drugs may likely serve as complementary therapies in cases of accidents with Bothrops moojeni, provided that such pharmacological treatments are administered immediately after the incident.

  11. Neurospora crassa fmf-1 encodes the homologue of the Schizosaccharomyces pombe Ste11p regulator of sexual development.

    Science.gov (United States)

    Iyer, Srividhya V; Ramakrishnan, Mukund; Kasbekar, Durgadas P

    2009-04-01

    The Neurospora crassa fmf-1 mutation exerts an unusual 'perithecium-dominant' developmental arrest; fmf-1 x fmf-1+ cross becomes arrested in perithecial development regardless of whether the mutant participates in the cross as the male or female parent. We localized fmf-1 to the LG IL genome segment between the centromere-proximal breakpoint of the chromosome segment duplication Dp(IL)39311 and the centromere. By mapping crossovers with respect to RFLP markers in this region we further localized fmf-1 to an approximately 34-kb-genome segment. Partial sequencing of this segment revealed a point mutation in the gene NCU 09387.1, a homologue of the Schizosaccharomyces pombe ste11+ regulator of sexual development. The fmf-1 mutation did not complement a NCU 09387.1 deletion mutation, and transformation with wild-type NCU 09387.1 complemented fmf-1. S. pombe Ste11 protein (Ste11p) is a transcription factor required for sexual differentiation and for the expression of genes required for mating pheromone signalling in matP and matM cells. If FMF-1 also plays a corresponding role in mating pheromone signalling in Neurospora, then protoperithecia in an fmf-1 x fmf-1+ cross would be unable to either send or receive sexual differentiation signals and thus become arrested in development.

  12. Transcriptomic analysis of common carp anterior kidney during Cyprinid herpesvirus 3 infection: Immunoglobulin repertoire and homologue functional divergence

    Science.gov (United States)

    Neave, Matthew J.; Sunarto, Agus; McColl, Kenneth A.

    2017-01-01

    Cyprinid herpesvirus 3 (CyHV-3) infects koi and common carp and causes widespread mortalities. While the virus is a significant concern for aquaculture operations in many countries, in Australia the virus may be a useful biocontrol agent for pest carp. However, carp immune responses to CyHV-3, and the molecular mechanisms underpinning resistance, are not well understood. Here we used RNA-Seq on carp during different phases of CyHV-3 infection to detect the gene expression dynamics of both host and virus simultaneously. During acute CyHV-3 infection, the carp host modified the expression of genes involved in various immune systems and detoxification pathways. Moreover, the activated pathways were skewed toward humoral immune responses, which may have been influenced by the virus itself. Many immune-related genes were duplicated in the carp genome, and often these were expressed differently across the infection phases. Of particular interest were two interleukin-10 homologues that were not expressed synchronously, suggesting neo- or sub-functionalization. The carp immunoglobulin repertoire significantly diversified during active CyHV-3 infection, which was followed by the selection of high-affinity B-cells. This is indicative of a developing adaptive immune response, and is the first attempt to use RNA-Seq to understand this process in fish during a viral infection. PMID:28148967

  13. Mammalian mitochondrial intermediate peptidase: Structure/function analysis of a new homologue from Schizophyllum commune and relationship to thimet oligopeptidases

    Energy Technology Data Exchange (ETDEWEB)

    Isaya, G.; Sakati, W.R.; Rollins, R.A. [Yale Univ. School of Medicine, New Haven, CT (United States)] [and others

    1995-08-10

    Mitochondrial intermediate peptidase (MIP) is a component of the mitochondrial protein import machinery required for maturation of nuclear-encoded precursor proteins targeted to the mitochondrial matrix or inner membrane. We previously characterized this enzyme in rat (RMIP) and Saccharomyces cerevisiae (YMIP) and showed that MIP activity is essential for mitochondrial function in yeast. We have now defined the structure of a new MIP homologue (SMIP) from the basidiomycete fungus Schizophyllum commune. SMIP includes 4 exons of 523, 486, 660, and 629 bp separated by 3 short introns. The predicted SMIP, YMIP, and RMIP sequences share 31-37% identity and 54-57% similarity over 700 amino acids. When SMIP and RMIP were expressed in a yeast mip1{Delta} mutant, they were both able to rescue the respiratory-deficient phenotype caused by genetic inactivation of YMIP, indicating that the function of this enzyme is conserved in eukaryotes. Moreover, the MIP sequences show 20-24% identity and 40-47% similarity to a family of oligopeptidases from bacteria, yeast, and mammals. MIP and these proteins are characterized by a highly conserved motif, F-H-E-X-G-H-(X){sub 12}-G-(X){sub 5}-D-(X){sub 2}-E-X-P-S-(X){sub 3}-E-X, centered around a zinc-binding site and appear to represent a new family of genes associated with proteolytic processing in the mitochondrial and cytosolic compartments. 48 refs., 8 figs.

  14. Mammalian mitochondrial intermediate peptidase: structure/function analysis of a new homologue from Schizophyllum commune and relationship to thimet oligopeptidases.

    Science.gov (United States)

    Isaya, G; Sakati, W R; Rollins, R A; Shen, G P; Hanson, L C; Ullrich, R C; Novotny, C P

    1995-08-10

    Mitochondrial intermediate peptidase (MIP) is a component of the mitochondrial protein import machinery required for maturation of nuclear-encoded precursor proteins targeted to the mitochondrial matrix or inner membrane. We previously characterized this enzyme in rat (RMIP) and Saccharomyces cerevisiae (YMIP) and showed that MIP activity is essential for mitochondrial function in yeast. We have now defined the structure of a new MIP homologue (SMIP) from the basidiomycete fungus Schizophyllum commune. SMIP includes 4 exons of 523, 486, 660, and 629 bp separated by 3 short introns. The predicted SMIP, YMIP, and RMIP sequences share 31-37% identity and 54-57% similarity over 700 amino acids. When SMIP and RMIP were expressed in a yeast mip1 delta mutant, they were both able to rescue the respiratory-deficient phenotype caused by genetic inactivation of YMIP, indicating that the function of this enzyme is conserved in eukaryotes. Moreover, the MIP sequences show 20-24% identity and 40-47% similarity to a family of oligopeptidases from bacteria, yeast, and mammals. MIP and these proteins are characterized by a highly conserved motif, F-H-E-X-G-H-(X)2-H-(X)12-G-(X)5-D-(X)2-E-X-P-S-(X)3-E-X, centered around a zinc-binding site and appear to represent a new family of genes associated with proteolytic processing in the mitochondrial and cytosolic compartments.

  15. 2D and 3D crystallization of a bacterial homologue of human vitamin C membrane transport proteins.

    Science.gov (United States)

    Jeckelmann, Jean-Marc; Harder, Daniel; Ucurum, Zöhre; Fotiadis, Dimitrios

    2014-10-01

    Most organisms are able to synthesize vitamin C whereas humans are not. In order to contribute to the elucidation of the molecular working mechanism of vitamin C transport through biological membranes, we cloned, overexpressed, purified, functionally characterized, and 2D- and 3D-crystallized a bacterial protein (UraDp) with 29% of amino acid sequence identity to the human sodium-dependent vitamin C transporter 1 (SVCT1). Ligand-binding experiments by scintillation proximity assay revealed that uracil is a substrate preferably bound to UraDp. For structural analysis, we report on the production of tubular 2D crystals and present a first projection structure of UraDp from negatively stained tubes. On the other hand the successful growth of UraDp 3D crystals and their crystallographic analysis is described. These 3D crystals, which diffract X-rays to 4.2Å resolution, pave the way towards the high-resolution crystal structure of a bacterial homologue with high amino acid sequence identity to human SVCT1.

  16. Differential expression of metallothionein type-2 homologues in leaves and roots of Black pepper (Piper nigrum L

    Directory of Open Access Journals (Sweden)

    Susan M. Alex

    2008-01-01

    Full Text Available Black pepper (Piper nigrum L., member of the family Piperaceae is indigenous to India and is one of the most widely used spices in the world. In this paper we report the results of our attempts to identify a set of genes differentially expressed in the leaves of Piper nigrum, which could facilitate targeted engineering of this valuable crop. A PCR-based Suppression Subtractive Hybridization (SSH technique was used to generate a leaf-specific subtracted cDNA library of Piper nigrum. A tester population of leaf cDNA was subtracted with a root derived driver cDNA. The efficiency of subtraction was confirmed by PCR analysis using the housekeeping gene actin. On sequence analysis, almost 30% of the clones showed homology to metallothionein type-2 gene. The predominance of metallothionein transcripts in the leaf was further confirmed using Real-Time PCR analyses and Northern blot. The possible role of metallothionein type-2 homologues in the leaf is discussed along with the feasibility of using SSH technique for identification of more number of tissue-specific genes from Piper nigrum.

  17. Transcriptomic analysis of common carp anterior kidney during Cyprinid herpesvirus 3 infection: Immunoglobulin repertoire and homologue functional divergence.

    Science.gov (United States)

    Neave, Matthew J; Sunarto, Agus; McColl, Kenneth A

    2017-02-02

    Cyprinid herpesvirus 3 (CyHV-3) infects koi and common carp and causes widespread mortalities. While the virus is a significant concern for aquaculture operations in many countries, in Australia the virus may be a useful biocontrol agent for pest carp. However, carp immune responses to CyHV-3, and the molecular mechanisms underpinning resistance, are not well understood. Here we used RNA-Seq on carp during different phases of CyHV-3 infection to detect the gene expression dynamics of both host and virus simultaneously. During acute CyHV-3 infection, the carp host modified the expression of genes involved in various immune systems and detoxification pathways. Moreover, the activated pathways were skewed toward humoral immune responses, which may have been influenced by the virus itself. Many immune-related genes were duplicated in the carp genome, and often these were expressed differently across the infection phases. Of particular interest were two interleukin-10 homologues that were not expressed synchronously, suggesting neo- or sub-functionalization. The carp immunoglobulin repertoire significantly diversified during active CyHV-3 infection, which was followed by the selection of high-affinity B-cells. This is indicative of a developing adaptive immune response, and is the first attempt to use RNA-Seq to understand this process in fish during a viral infection.

  18. Molecular cloning, sequence characterization and expression analysis of a CD63 homologue from the coleopteran beetle, Tenebrio molitor.

    Science.gov (United States)

    Patnaik, Bharat Bhusan; Kang, Seong Min; Seo, Gi Won; Lee, Hyo Jeong; Patnaik, Hongray Howrelia; Jo, Yong Hun; Tindwa, Hamisi; Lee, Yong Seok; Lee, Bok Luel; Kim, Nam Jung; Bang, In Seok; Han, Yeon Soo

    2013-10-15

    CD63, a member of the tetraspanin membrane protein family, plays a pivotal role in cell growth, motility, signal transduction, host-pathogen interactions and cancer. In this work, the cDNA encoding CD63 homologue (TmCD63) was cloned from larvae of a coleopteran beetle, Tenebrio molitor. The cDNA is comprised of an open reading frame of 705 bp, encoding putative protein of 235 amino acid residues. In silico analysis shows that the protein has four putative transmembrane domains and one large extracellular loop. The characteristic "Cys-Cys-Gly" motif and "Cys188" residues are highly conserved in the large extracellular loop. Phylogenetic analysis of TmCD63 revealed that they belong to the insect cluster with 50%-56% identity. Analysis of spatial expression patterns demonstrated that TmCD63 mRNA is mainly expressed in gut and Malphigian tubules of larvae and the testis of the adult. Developmental expression patterns of CD63 mRNA showed that TmCD63 transcripts are detected in late larval, pupal and adult stages. Interestingly, TmCD63 transcripts are upregulated to the maximum level of 4.5 fold, in response to DAP-type peptidoglycan during the first 6 h, although other immune elicitors also caused significant increase to the transcript level at later time-points. These results suggest that CD63 might contribute to T. molitor immune response against various microbial pathogens.

  19. Molecular Cloning, Sequence Characterization and Expression Analysis of a CD63 Homologue from the Coleopteran Beetle, Tenebrio molitor

    Directory of Open Access Journals (Sweden)

    Yeon Soo Han

    2013-10-01

    Full Text Available CD63, a member of the tetraspanin membrane protein family, plays a pivotal role in cell growth, motility, signal transduction, host-pathogen interactions and cancer. In this work, the cDNA encoding CD63 homologue (TmCD63 was cloned from larvae of a coleopteran beetle, Tenebrio molitor. The cDNA is comprised of an open reading frame of 705 bp, encoding putative protein of 235 amino acid residues. In silico analysis shows that the protein has four putative transmembrane domains and one large extracellular loop. The characteristic “Cys-Cys-Gly” motif and “Cys188” residues are highly conserved in the large extracellular loop. Phylogenetic analysis of TmCD63 revealed that they belong to the insect cluster with 50%–56% identity. Analysis of spatial expression patterns demonstrated that TmCD63 mRNA is mainly expressed in gut and Malphigian tubules of larvae and the testis of the adult. Developmental expression patterns of CD63 mRNA showed that TmCD63 transcripts are detected in late larval, pupal and adult stages. Interestingly, TmCD63 transcripts are upregulated to the maximum level of 4.5 fold, in response to DAP-type peptidoglycan during the first 6 h, although other immune elicitors also caused significant increase to the transcript level at later time-points. These results suggest that CD63 might contribute to T. molitor immune response against various microbial pathogens.

  20. PP-O and PP-V, Monascus pigment homologues, production, and phylogenetic analysis in Penicillium purpurogenum.

    Science.gov (United States)

    Arai, Teppei; Kojima, Ryo; Motegi, Yoshiki; Kato, Jun; Kasumi, Takafumi; Ogihara, Jun

    2015-12-01

    The production of pigments as secondary metabolites by microbes is known to vary by species and by physiological conditions within a single strain. The fungus strain Penicillium purpurogenum IAM15392 has been found to produce violet pigment (PP-V) and orange pigment (PP-O),Monascus azaphilone pigment homologues, when grown under specific culture conditions. In this study, we analysed PP-V and PP-O production capability in seven strains of P. purpurogenum in addition to strain IAM15392 under specific culture conditions. The pigment production pattern of five strains cultivated in PP-V production medium was similar to that of strain IAM15392, and all violet pigments produced by these five strains were confirmed to be PP-V. Strains that did not produce pigment were also identified. In addition, two strains cultivated in PP-O production medium produced a violet pigment identified as PP-V. The ribosomal DNA (rDNA) internal transcribed spacer (ITS) region sequences from the eight P. purpurogenum strains were sequenced and used to construct a neighbor-joining phylogenetic tree. PP-O and PP-V production of P. purpurogenum was shown to be related to phylogenetic placement based on rDNA ITS sequence. Based on these results, two hypotheses for the alteration of pigment production of P. purpurogenum in evolution were proposed.

  1. Ectopic expression of Cvh (Chicken Vasa homologue) mediates the reprogramming of chicken embryonic stem cells to a germ cell fate.

    Science.gov (United States)

    Lavial, Fabrice; Acloque, Hervé; Bachelard, Elodie; Nieto, M Angela; Samarut, Jacques; Pain, Bertrand

    2009-06-01

    When they are derived from blastodermal cells of the pre-primitive streak in vitro, the pluripotency of Chicken Embryonic Stem Cells (cESC) can be controlled by the cPouV and Nanog genes. These cESC can differentiate into derivatives of the three germ layers both in vitro and in vivo, but they only weakly colonize the gonads of host embryos. By contrast, non-cultured blastodermal cells and long-term cultured chicken primordial germ cells maintain full germline competence. This restriction in the germline potential of the cESC may result from either early germline determination in the donor embryos or it may occur as a result of in vitro culture. We are interested in understanding the genetic determinants of germline programming. The RNA binding protein Cvh (Chicken Vasa Homologue) is considered as one such determinant, although its role in germ cell physiology is still unclear. Here we show that the exogenous expression of Cvh, combined with appropriate culture conditions, induces cESC reprogramming towards a germ cell fate. Indeed, these cells express the Dazl, Tudor and Sycp3 germline markers, and they display improved germline colonization and adopt a germ cell fate when injected into recipient embryos. Thus, our results demonstrate that Vasa can drive ES cell differentiation towards the germ cell lineage, both in vitro and in vivo.

  2. An alpha-catulin homologue controls neuromuscular function through localization of the dystrophin complex and BK channels in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Linu S Abraham

    2010-08-01

    Full Text Available The large conductance, voltage- and calcium-dependent potassium (BK channel serves as a major negative feedback regulator of calcium-mediated physiological processes and has been implicated in muscle dysfunction and neurological disorders. In addition to membrane depolarization, activation of the BK channel requires a rise in cytosolic calcium. Localization of the BK channel near calcium channels is therefore critical for its function. In a genetic screen designed to isolate novel regulators of the Caenorhabditis elegans BK channel, SLO-1, we identified ctn-1, which encodes an α-catulin homologue with homology to the cytoskeletal proteins α-catenin and vinculin. ctn-1 Mutants resemble slo-1 loss-of-function mutants, as well as mutants with a compromised dystrophin complex. We determined that CTN-1 uses two distinct mechanisms to localize SLO-1 in muscles and neurons. In muscles, CTN-1 utilizes the dystrophin complex to localize SLO-1 channels near L-type calcium channels. In neurons, CTN-1 is involved in localizing SLO-1 to a specific domain independent of the dystrophin complex. Our results demonstrate that CTN-1 ensures the localization of SLO-1 within calcium nanodomains, thereby playing a crucial role in muscles and neurons.

  3. The C. elegans CBFbeta homologue BRO-1 interacts with the Runx factor, RNT-1, to promote stem cell proliferation and self-renewal.

    Science.gov (United States)

    Kagoshima, Hiroshi; Nimmo, Rachael; Saad, Nicole; Tanaka, Junko; Miwa, Yoshihiro; Mitani, Shohei; Kohara, Yuji; Woollard, Alison

    2007-11-01

    In this report, we investigate the C. elegans CBFbeta homologue, BRO-1. bro-1 mutants have a similar male-specific sensory ray loss phenotype to rnt-1 (the C. elegans homologue of the mammalian CBFbeta-interacting Runx factors), caused by failed cell divisions in the seam lineages. Our studies indicate that BRO-1 and RNT-1 form a cell proliferation-promoting complex, and that BRO-1 increases both the affinity and specificity of RNT-1-DNA interactions. Overexpression of bro-1, like rnt-1, leads to an expansion of seam cell number and co-overexpression of bro-1 and rnt-1 results in massive seam cell hyperplasia. Finally, we find that BRO-1 appears to act independently of RNT-1 in certain situations. These studies provide new insights into the function and regulation of this important cancer-associated DNA-binding complex in stem cells and support the view that Runx/CBFbeta factors have oncogenic potential.

  4. Snake venom toxins. The amino-acid sequence of a short-neurotoxin homologue from Dendroaspis polylepis polylepis (black mamba) venom.

    Science.gov (United States)

    Strydom, D J

    1977-06-01

    The third most abundant component of black mamba venom, named FS2, was sequenced with the aid of sequenator studies and peptides derived by tryptic and chymotryptic digestion. Cyanogen bromide digests provided extra information to support the proposed structure. This protein is a homologue of the short neurotoxins of snake venom, but is much less toxic. Its structure is quite different from both neurotoxins and the other mamba proteins, called angusticeps types (neurotoxin homologues). Comparison of the known angusticeps-type toxins from mamba venom with mamba neurotoxins and each other leads to proposals that these proteins of low toxicity are inventions of the group of mambas and that three different, as yet unknown, functions will be associated with the three subgroups that are discernable.

  5. Ionization potentials and electron affinities of the superheavy elements 115-117 and their sixth-row homologues Bi, Po, and At

    Science.gov (United States)

    Borschevsky, A.; Pašteka, L. F.; Pershina, V.; Eliav, E.; Kaldor, U.

    2015-02-01

    Calculations of the first and second ionization potentials and electron affinities of superheavy elements 115-117 are presented. The calculations are performed in the framework of the Dirac-Coulomb Hamiltonian, and the results are corrected for the Breit and QED contributions. Correlation is treated by the relativistic coupled cluster approach with single, double, and perturbative triple excitations [CCSD(T)]. The same approach is used to calculate the ionization potentials and electron affinities of the lighter homologues, Bi, Po, and At. Comparison of the available experimental values for these atoms, namely, the first ionization potentials (IPs) of Bi, Po, and At and the second IP and EA of Bi, with our results shows excellent agreement, within a few hundredths of an eV, lending credence to our predictions for their superheavy homologues. High-accuracy predictions are also made for the second ionization potentials and electron affinities of Po and At, where no experiment is available.

  6. Characterization of synthetic routes to 'Bromo-DragonFLY' and benzodifuranyl isopropylamine homologues utilizing ketone intermediates. Part 1: synthesis of ketone precursors.

    Science.gov (United States)

    O'Connor, Richard E; Keating, John J

    2014-01-01

    Bromo-DragonFLY (BDF) and many of its analogues are misused as recreational drugs due to their potency as psychoactive substances. To date, none of the published routes to these designer amphetamines have exploited a ketone intermediate. It is well known that benzyl methyl ketone (BMK) can be employed as a precursor in the synthesis of amphetamine. Similarly, it is reasonable to assume that ketone precursors may potentially be utilized in the clandestine synthesis of BDF and its homologues. This paper describes the multifaceted synthesis of novel precursor ketones structurally related to BDF, namely benzodifuranyl propanone 16, its tetrahydrobenzodifuranyl homologue 8, and their brominated analogues 12 and 20. Their characterization by Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy ((1) H-NMR), carbon nuclear magnetic resonance spectroscopy ((13) C-NMR), high performance liquid chromatography (HPLC), gas chromatography (GC) and mass spectrometry (MS) is also described.

  7. Cloning of the Rhesus Lymphocryptovirus Viral Capsid Antigen and Epstein-Barr Virus-Encoded Small RNA Homologues and Use in Diagnosis of Acute and Persistent Infections

    OpenAIRE

    Rao, Pasupuleti; Jiang, Hua; Wang, Fred

    2000-01-01

    Epstein-Barr virus (EBV) is the most common cause of infectious mononucleosis and is associated with the development of several human malignancies. A closely related herpesvirus in the same lymphocryptovirus (LCV) genera as EBV naturally infects rhesus monkeys and provides an important animal model for studying EBV pathogenesis. We cloned the small viral capsid antigen (sVCA) homologue from the rhesus LCV and developed a peptide enzyme-linked immunosorbent assay (ELISA) to determine whether e...

  8. Broca's region: novel organizational principles and multiple receptor mapping.

    Directory of Open Access Journals (Sweden)

    Katrin Amunts

    Full Text Available There is a considerable contrast between the various functions assigned to Broca's region and its relatively simple subdivision into two cytoarchitectonic areas (44 and 45. Since the regional distribution of transmitter receptors in the cerebral cortex has been proven a powerful indicator of functional diversity, the subdivision of Broca's region was analyzed here using a multireceptor approach. The distribution patterns of six receptor types using in vitro receptor autoradiography revealed previously unknown areas: a ventral precentral transitional cortex 6r1, dorsal and ventral areas 44d and 44v, anterior and posterior areas 45a and 45p, and areas op8 and op9 in the frontal operculum. A significant lateralization of receptors was demonstrated with respect to the cholinergic M(2 receptor, particularly in area 44v+d. We propose a new concept of the anterior language region, which elucidates the relation between premotor cortex, prefrontal cortex, and Broca's region. It offers human brain homologues to the recently described subdivision of area 45, and the segregation of the ventral premotor cortex in macaque brains. The results provide a novel structural basis of the organization of language regions in the brain.

  9. Characterization of the cDNA encoding a BPI/LBP homologue in venom gland of the hundred-pace snake Deinagkistrodon acutus

    Directory of Open Access Journals (Sweden)

    Jianrao HU, Mingfu CAO, Jiong Chen

    2009-10-01

    Full Text Available Bactericidal/permeability-increasing protein (BPI and LPS-binding protein (LBP play an important role in host defence. Current evidence shows that BPI/LBP may be widely existed in different cells and tissue types of animals. A full-length cDNA clone encoding a BPI/LBP homologue (dBPI, 1757bp in size, was characterized in venom gland of the hundred-pace snake Deinagkistrodon acutus. Its deduced amino acid sequence of 417 residues had 13.8%–21.5% identity to BPI like 1(BPIL1 and BPI like 3(BPIL3 of other animals. Conserved cysteine residues which are involved in disulfide bond formation between the final strand of the N-terminal beta sheet and the long alpha helix of BPI are identified as Cys146-Cys183 of dBPI. Phylogenetic tree analysis showed that the BPI/LBP homologues formed five large clusters and dBPI was in a large cluster including BPIL1 and BPIL3. dBPI mRNA shows a tissue specific expression in venom gland. This is the first study to identify the cDNA encoding BPI/LBP homologues from reptiles [Current Zoology 55 (5: –2009].

  10. Whole genome sequencing enables the characterization of BurI, a LuxI homologue of Burkholderia cepacia strain GG4

    Directory of Open Access Journals (Sweden)

    Kah Yan How

    2015-08-01

    Full Text Available Quorum sensing is a mechanism for regulating proteobacterial gene expression in response to changes in cell population. In proteobacteria, N-acyl homoserine lactone (AHL appears to be the most widely used signalling molecules in mediating, among others, the production of extracellular virulence factors for survival. In this work, the genome of B. cepacia strain GG4, a plasmid-free strain capable of AHL synthesis was explored. In silico analysis of the 6.6 Mb complete genome revealed the presence of a LuxI homologue which correspond to Type I quorum sensing. Here, we report the molecular cloning and characterization of this LuxI homologue, designated as BurI. This 609 bp gene was cloned and overexpressed in Escherichia coli BL21(DE3. The purified protein was approximately 25 kDa and is highly similar to several autoinducer proteins of the LuxI family among Burkholderia species. To verify the AHL synthesis activity of this protein, high resolution liquid chromatography-mass spectrometry analysis revealed the production of 3-oxo-hexanoylhomoserine lactone, N-octanoylhomoserine lactone and 3-hydroxy-octanoylhomoserine lactone from induced E. coli BL21 harboring the recombinant BurI. Our data show, for the first time, the cloning and characterization of the LuxI homologue from B. cepacia strain GG4 and confirmation of its AHL synthesis activity.

  11. Whole genome sequencing enables the characterization of BurI, a LuxI homologue of Burkholderia cepacia strain GG4.

    Science.gov (United States)

    How, Kah Yan; Hong, Kar Wai; Chan, Kok-Gan

    2015-01-01

    Quorum sensing is a mechanism for regulating proteobacterial gene expression in response to changes in cell population. In proteobacteria, N-acyl homoserine lactone (AHL) appears to be the most widely used signalling molecules in mediating, among others, the production of extracellular virulence factors for survival. In this work, the genome of B. cepacia strain GG4, a plasmid-free strain capable of AHL synthesis was explored. In silico analysis of the 6.6 Mb complete genome revealed the presence of a LuxI homologue which correspond to Type I quorum sensing. Here, we report the molecular cloning and characterization of this LuxI homologue, designated as BurI. This 609 bp gene was cloned and overexpressed in Escherichia coli BL21(DE3). The purified protein was approximately 25 kDa and is highly similar to several autoinducer proteins of the LuxI family among Burkholderia species. To verify the AHL synthesis activity of this protein, high resolution liquid chromatography-mass spectrometry analysis revealed the production of 3-oxo-hexanoylhomoserine lactone, N-octanoylhomoserine lactone and 3-hydroxy-octanoylhomoserine lactone from induced E. coli BL21 harboring the recombinant BurI. Our data show, for the first time, the cloning and characterization of the LuxI homologue from B. cepacia strain GG4 and confirmation of its AHL synthesis activity.

  12. Characterization of the cDNA encoding a BPI/LBP homologue in venom gland of the hundred-pace snake Deinagkistrodon acutus

    Institute of Scientific and Technical Information of China (English)

    Jianrao HU; Mingfu CAO; Jiong CHEN

    2009-01-01

    Bactericidal/permeability-increasing protein (BPI) and LPS-binding protein (LBP) play an important role in host defence. Current evidence shows that BPI/LBP may be widely existed in different cells and tissue types of animals. A full-length cDNA clone encoding a BPI/LBP homologue (dBPI), 1757 bp in size, was characterized in venom gland of the hundred-pace snake Deinagkistrodon acutus. Its deduced amino acid sequence of 417 residues had 13.8% - 21.5% identity to BPI like 1 (BPIL1) and BPI like 3 (BPIL3) of other animals. Conserved cysteine residues which are involved in disulfide bond formation between the final strand of the N-terminal beta sheet and the long alpha helix of BPI are identified as Cys146-Cys183 of dBPI. Phylogenetic tree analysis showed that the BPI/LBP homologues formed five large clusters and dBPl was in a large cluster including BPIL1 and BPIL3. dBPI mRNA shows a tissue specific expression in venom gland. This is the fast study to identify the cDNA encoding BPI/LBP homologues from reptiles [Current Zoology 55 (5) : 376 - 382, 2009].

  13. Metal-Organic Framework with Aromatic Rings Tentacles: High Sulfur Storage in Li-S Batteries and Efficient Benzene Homologues Distinction.

    Science.gov (United States)

    Li, Meng-Ting; Sun, Yu; Zhao, Kai-Sen; Wang, Zhao; Wang, Xin-Long; Su, Zhong-Min; Xie, Hai-Ming

    2016-12-07

    We designed and fabricated a fluorophore-containing tetradentate carboxylate ligand-based metal-organic framework (MOF) material with open and semiopen channels, which acted as the host for sulfur trapped in Li-S batteries and sensor of benzene homologues. These channels efficiently provide a π-π* conjugated matrix for the charge transfer and guest molecule trapping. The open channel ensured a much higher loading quantitative of sulfur (S content-active material, 72 wt %; electrode, 50.4 wt %) than most of the MOF/sulfur composites, while the semiopen channel possessing aromatic rings tentacles guaranteed an outstanding specific discharge capacity (1092 mA h g(-1) at 0.1 C) accompanied by good cycling stability. To our surprise, benefiting from special π-π* conjugated conditions, compound 1 could be a chemical sensor for benzene homologues, especially for 1,2,4-trimethylbenzene (1,2,4-TMB). This is the first example of MOFs materials serving as a sensor of 1,2,4-TMB among benzene homologues. Our works may be worthy of use for references in other porous materials systems to manufacture more long-acting Li-S batteries and sensitive chemical sensors.

  14. A novel role of 'pseudo'γ-butyrolactone receptors in controlling γ-butyrolactone biosynthesis in Streptomyces.

    Science.gov (United States)

    Wang, Juan; Wang, Weishan; Wang, Linqi; Zhang, Guifeng; Fan, Keqiang; Tan, Huarong; Yang, Keqian

    2011-10-01

    In streptomycetes, a quorum-sensing mechanism mediated by γ-butyrolactones (GBLs) and their cognate receptors was known to trigger secondary metabolism and morphological differentiation. However, many aspects on the control of GBL signal production are not understood. In this work, we report that ScbR2, the pseudo GBL receptor in Streptomyces coelicolor, negatively controls the biosynthesis of γ-butyrolactone (SCB1) by directly repressing the transcription of scbA, which encodes the key enzyme for SCB1 biosynthesis. Similarly, the pseudo GBL receptor JadR2 in Streptomyces venezuelae was shown to repress the expression of jadW1, which also encodes the putative GBL synthase. These regulatory relationships were verified in Escherichia coli using lux-based reporter constructs. Additionally, the temporal expression profiles of scbA, scbR2 and scbR (receptor gene for SCB1) were examined in Streptomyces coelicolor, which showed the sequential expression of ScbR/R2 regulators in the control of SCB1 production. Overall, our results clearly demonstrated that pseudo GBL receptors play a novel role in controlling GBL biosynthesis in streptomycetes. As ScbR/R2 homologues and their binding sites upstream of GBL synthase genes are commonly found in Streptomyces species, and ScbR2 homologues cross-recognize each other's target promoters, the ScbA/R/R2 quorum-sensing regulatory system appears to represent an evolutionarily conserved signal control mechanism.

  15. BCAR1, a human homologue of the adapter protein p130Cas, and antiestrogen resistance in breast cancer cells

    NARCIS (Netherlands)

    A. Brinkman (Arend); S. van der Flier (Silvia); E.M. Kok (Elisabeth); L.C.J. Dorssers (Lambert)

    2000-01-01

    textabstractBACKGROUND: Treatment of breast cancer with the antiestrogen tamoxifen is effective in approximately one half of the patients with estrogen receptor-positive disease, but tumors recur frequently because of the development of metastases that are resistant to

  16. BCAR1, a human homologue of the adapter protein p130Cas, and antiestrogen resistance in breast cancer cells

    NARCIS (Netherlands)

    A. Brinkman (Arend); S. van der Flier (Silvia); E.M. Kok (Elisabeth); L.C.J. Dorssers (Lambert)

    2000-01-01

    textabstractBACKGROUND: Treatment of breast cancer with the antiestrogen tamoxifen is effective in approximately one half of the patients with estrogen receptor-positive disease, but tumors recur frequently because of the development of metastases that are resistant to

  17. cDNA expression library screening and identification of two novel antigens, ubiquitin and receptor for activated C kinase (RACK) homologue, of the fish parasite Trypanosoma carassii

    NARCIS (Netherlands)

    Ruszczyk, A.; Joerink, M.; Guldenaar, C.; Hermsen, G.J.; Savelkoul, H.F.J.; Wiegertjes, G.F.

    2008-01-01

    Trypanosoma carassii is a kinetoplastid parasite infecting cyprinid fish with a high prevalence in nature. Antibodies have been shown to play a protective role in the immune response against this parasite in common carp, Cyprinus carpio. To identify immunogenic and putative protective T. carassii an

  18. Opioid Receptors.

    Science.gov (United States)

    Stein, Christoph

    2016-01-01

    Opioids are the oldest and most potent drugs for the treatment of severe pain. Their clinical application is undisputed in acute (e.g., postoperative) and cancer pain, but their long-term use in chronic pain has met increasing scrutiny. This article reviews mechanisms underlying opioid analgesia and other opioid actions. It discusses the structure, function, and plasticity of opioid receptors; the central and peripheral sites of analgesic actions and side effects; endogenous and exogenous opioid receptor ligands; and conventional and novel opioid compounds. Challenging clinical situations, such as the tension between chronic pain and addiction, are also illustrated.

  19. Genetic analysis of the spindle checkpoint genes san-1, mdf-2, bub-3 and the CENP-F homologues hcp-1 and hcp-2 in Caenorhabditis elegans.

    Science.gov (United States)

    Hajeri, Vinita A; Stewart, Anil M; Moore, Landon L; Padilla, Pamela A

    2008-02-04

    The spindle checkpoint delays the onset of anaphase until all sister chromatids are aligned properly at the metaphase plate. To investigate the role san-1, the MAD3 homologue, has in Caenorhabditis elegans embryos we used RNA interference (RNAi) to identify genes synthetic lethal with the viable san-1(ok1580) deletion mutant. The san-1(ok1580) animal has low penetrating phenotypes including an increased incidence of males, larvae arrest, slow growth, protruding vulva, and defects in vulva morphogenesis. We found that the viability of san-1(ok1580) embryos is significantly reduced when HCP-1 (CENP-F homologue), MDF-1 (MAD-1 homologue), MDF-2 (MAD-2 homologue) or BUB-3 (predicted BUB-3 homologue) are reduced by RNAi. Interestingly, the viability of san-1(ok1580) embryos is not significantly reduced when the paralog of HCP-1, HCP-2, is reduced. The phenotype of san-1(ok1580);hcp-1(RNAi) embryos includes embryonic and larval lethality, abnormal organ development, and an increase in abnormal chromosome segregation (aberrant mitotic nuclei, anaphase bridging). Several of the san-1(ok1580);hcp-1(RNAi) animals displayed abnormal kinetochore (detected by MPM-2) and microtubule structure. The survival of mdf-2(RNAi);hcp-1(RNAi) embryos but not bub-3(RNAi);hcp-1(RNAi) embryos was also compromised. Finally, we found that san-1(ok1580) and bub-3(RNAi), but not hcp-1(RNAi) embryos, were sensitive to anoxia, suggesting that like SAN-1, BUB-3 has a functional role as a spindle checkpoint protein. Together, these data suggest that in the C. elegans embryo, HCP-1 interacts with a subset of the spindle checkpoint pathway. Furthermore, the fact that san-1(ok1580);hcp-1(RNAi) animals had a severe viability defect whereas in the san-1(ok1580);hcp-2(RNAi) and san-1(ok1580);hcp-2(ok1757) animals the viability defect was not as severe suggesting that hcp-1 and hcp-2 are not completely redundant.

  20. Genetic analysis of the spindle checkpoint genes san-1, mdf-2, bub-3 and the CENP-F homologues hcp-1 and hcp-2 in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Moore Landon L

    2008-02-01

    Full Text Available Abstract Background The spindle checkpoint delays the onset of anaphase until all sister chromatids are aligned properly at the metaphase plate. To investigate the role san-1, the MAD3 homologue, has in Caenorhabditis elegans embryos we used RNA interference (RNAi to identify genes synthetic lethal with the viable san-1(ok1580 deletion mutant. Results The san-1(ok1580 animal has low penetrating phenotypes including an increased incidence of males, larvae arrest, slow growth, protruding vulva, and defects in vulva morphogenesis. We found that the viability of san-1(ok1580 embryos is significantly reduced when HCP-1 (CENP-F homologue, MDF-1 (MAD-1 homologue, MDF-2 (MAD-2 homologue or BUB-3 (predicted BUB-3 homologue are reduced by RNAi. Interestingly, the viability of san-1(ok1580 embryos is not significantly reduced when the paralog of HCP-1, HCP-2, is reduced. The phenotype of san-1(ok1580;hcp-1(RNAi embryos includes embryonic and larval lethality, abnormal organ development, and an increase in abnormal chromosome segregation (aberrant mitotic nuclei, anaphase bridging. Several of the san-1(ok1580;hcp-1(RNAi animals displayed abnormal kinetochore (detected by MPM-2 and microtubule structure. The survival of mdf-2(RNAi;hcp-1(RNAi embryos but not bub-3(RNAi;hcp-1(RNAi embryos was also compromised. Finally, we found that san-1(ok1580 and bub-3(RNAi, but not hcp-1(RNAi embryos, were sensitive to anoxia, suggesting that like SAN-1, BUB-3 has a functional role as a spindle checkpoint protein. Conclusion Together, these data suggest that in the C. elegans embryo, HCP-1 interacts with a subset of the spindle checkpoint pathway. Furthermore, the fact that san-1(ok1580;hcp-1(RNAi animals had a severe viability defect whereas in the san-1(ok1580;hcp-2(RNAi and san-1(ok1580;hcp-2(ok1757 animals the viability defect was not as severe suggesting that hcp-1 and hcp-2 are not completely redundant.

  1. A spinach O-acetylserine(thiollyase homologue, SoCSaseLP, suppresses cysteine biosynthesis catalysed by other enzyme isoforms

    Directory of Open Access Journals (Sweden)

    Miki Noda

    2016-06-01

    Full Text Available An enzyme, O-acetylserine(thiollyase (OASTL, also known as O-acetylserine sulfhydrylase or cysteine synthase (CSase, catalyses the incorporation of sulfide into O-acetylserine and produces cysteine. We previously identified a cDNA encoding an OASTL-like protein from Spinacia oleracea, (SoCSaseLP, but a recombinant SoCSaseLP produced in Escherichia coli did not show OASTL activity. The exon-intron structure of the SoCSaseLP gene shared conserved structures with other spinach OASTL genes. The SoCSaseLP and a Beta vulgaris homologue protein, KMT13462, comprise a unique clade in the phylogenetic tree of the OASTL family. Interestingly, when the SoCSaseLP gene was expressed in tobacco plants, total OASTL activity in tobacco leaves was reduced. This reduction in total OASTL activity was most likely caused by interference by SoCSaseLP with cytosolic OASTL. To investigate the possible interaction of SoCSaseLP with a spinach cytosolic OASTL isoform SoCSaseA, a pull-down assay was carried out. The recombinant glutathione S-transferase (GST-SoCSaseLP fusion protein was expressed in E. coli together with the histidine-tagged SoCSaseA protein, and the protein extract was subjected to glutathione affinity chromatography. The histidine-tagged SoCSaseA was co-purified with the GST-SoCSaseLP fusion protein, indicating the binding of SoCSaseLP to SoCSaseA. Consistent with this interaction, the OASTL activity of the co-purified SoCSaseA was reduced compared with the activity of SoCSaseA that was purified on its own. These results strongly suggest that SoCSaseLP negatively regulates the activity of other cytosolic OASTL family members by direct interaction.

  2. Genetic link between Cabeza, a Drosophila homologue of Fused in Sarcoma (FUS), and the EGFR signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Shimamura, Mai; Kyotani, Akane [Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585 (Japan); Insect Biomedical Research Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585 (Japan); Azuma, Yumiko [Department of Neurology, Kyoto Prefectural University of Medicine, 465 Kajii-cho,Kamigyo-ku, Kyoto 602-8566 (Japan); Yoshida, Hideki; Binh Nguyen, Thanh [Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585 (Japan); Insect Biomedical Research Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585 (Japan); Mizuta, Ikuko; Yoshida, Tomokatsu; Mizuno, Toshiki [Department of Neurology, Kyoto Prefectural University of Medicine, 465 Kajii-cho,Kamigyo-ku, Kyoto 602-8566 (Japan); Nakagawa, Masanori [North Medical Center, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566 (Japan); Tokuda, Takahiko, E-mail: ttokuda@koto.kpu-m.ac.jp [Department of Neurology, Kyoto Prefectural University of Medicine, 465 Kajii-cho,Kamigyo-ku, Kyoto 602-8566 (Japan); Department of Molecular Pathobiology of Brain Diseases, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566 (Japan); Yamaguchi, Masamitsu, E-mail: myamaguc@kit.ac.jp [Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585 (Japan); Insect Biomedical Research Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585 (Japan)

    2014-08-01

    Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease that causes progressive muscular weakness. Fused in Sarcoma (FUS) that has been identified in familial ALS is an RNA binding protein that is normally localized in the nucleus. However, its function in vivo is not fully understood. Drosophila has Cabeza (Caz) as a FUS homologue and specific knockdown of Caz in the eye imaginal disc and pupal retina using a GMR-GAL4 driver was here found to induce an abnormal morphology of the adult compound eyes, a rough eye phenotype. This was partially suppressed by expression of the apoptosis inhibitor P35. Knockdown of Caz exerted no apparent effect on differentiation of photoreceptor cells. However, immunostaining with an antibody to Cut that marks cone cells revealed fusion of these and ommatidia of pupal retinae. These results indicate that Caz knockdown induces apoptosis and also inhibits differentiation of cone cells, resulting in abnormal eye morphology in adults. Mutation in EGFR pathway-related genes, such as rhomboid-1, rhomboid-3 and mirror suppressed the rough eye phenotype induced by Caz knockdown. Moreover, the rhomboid-1 mutation rescued the fusion of cone cells and ommatidia observed in Caz knockdown flies. The results suggest that Caz negatively regulates the EGFR signaling pathway required for determination of cone cell fate in Drosophila. - Highlights: • Knockdown of Cabeza induced rough eye phenotype. • Knockdown of Cabeza induced fusion of cone cells in pupal retinae. • Knockdown of Cabeza induced apoptosis in pupal retinae. • Mutation in EGFR pathway-related genes suppressed the rough eye phenotype. • Cabeza may negatively regulate the EGFR pathway.

  3. Strboh A homologue of NADPH oxidase regulates wound-induced oxidative burst and facilitates wound-healing in potato tubers.

    Science.gov (United States)

    Kumar, G N Mohan; Iyer, Suresh; Knowles, N Richard

    2007-12-01

    During 30-months of storage at 4 degrees C, potato (Solanum tuberosum L.) tubers progressively lose the ability to produce superoxide in response to wounding, resist microbial infection, and develop a suberized wound periderm. Using differentially aged tubers, we demonstrate that Strboh A is responsible for the wound-induced oxidative burst in potato and aging attenuates its expression. In vivo superoxide production and NADPH oxidase (NOX) activity from 1-month-old tubers increased to a maximum 18-24 h after wounding and then decreased to barely detectable levels by 72 h. Wounding also induced a 68% increase in microsomal protein within 18 h. These wound-induced responses were lost over a 25- to 30-month storage period. Superoxide production and NOX activity were inhibited by diphenylene iodonium chloride, a specific inhibitor of NOX, which in turn effectively inhibited wound-healing and increased susceptibility to microbial infection and decay in 1-month-old tubers. Wound-induced superoxide production was also inhibited by EGTA-mediated destabilization of membranes. The ability to restore superoxide production to EGTA-treated tissue with Ca(+2) declined with advancing tuber age, likely a consequence of age-related changes in membrane architecture. Of the five homologues of NOX (Strboh A-D and F), wounding induced the expression of Strboh A in 6-month-old tubers but this response was absent in tubers stored for 25-30 months. Strboh A thus mediates the initial burst of superoxide in response to wounding of potato tubers; loss of its expression increases the susceptibility to microbial infection and contributes to the age-induced loss of wound-healing ability.

  4. Gibberellins regulate the transcription of the continuous flowering regulator, RoKSN, a rose TFL1 homologue.

    Science.gov (United States)

    Randoux, Marie; Jeauffre, Julien; Thouroude, Tatiana; Vasseur, François; Hamama, Latifa; Juchaux, Marjorie; Sakr, Soulaiman; Foucher, Fabrice

    2012-11-01

    The role of gibberellins (GAs) during floral induction has been widely studied in the annual plant Arabidopsis thaliana. Less is known about this control in perennials. It is thought that GA is a major regulator of flowering in rose. In spring, low GA content may be necessary for floral initiation. GA inhibited flowering in once-flowering roses, whereas GA did not block blooming in continuous-flowering roses. Recently, RoKSN, a homologue of TFL1, was shown to control continuous flowering. The loss of RoKSN function led to continuous flowering behaviour. The objective of this study was to understand the molecular control of flowering by GA and the involvement of RoKSN in this inhibition. In once-flowering rose, the exogenous application of GA(3) in spring inhibited floral initiation. Application of GA(3) during a short period of 1 month, corresponding to the floral transition, was sufficient to inhibit flowering. At the molecular level, RoKSN transcripts were accumulated after GA(3) treatment. In spring, this accumulation is correlated with floral inhibition. Other floral genes such as RoFT, RoSOC1, and RoAP1 were repressed in a RoKSN-dependent pathway, whereas RoLFY and RoFD repression was RoKSN independent. The RoKSN promoter contained GA-responsive cis-elements, whose deletion suppressed the response to GA in a heterologous system. In summer, once-flowering roses did not flower even after exogenous application of a GA synthesis inhibitor that failed to repress RoKSN. A model is presented for the GA inhibition of flowering in spring mediated by the induction of RoKSN. In summer, factors other than GA may control RoKSN.

  5. Atlantic cod (Gadus morhua L.) possesses three homologues of ISG15 with different expression kinetics and conjugation properties.

    Science.gov (United States)

    Furnes, Clemens; Kileng, Øyvind; Rinaldo, Christine Hanssen; Seppola, Marit; Jensen, Ingvill; Robertsen, Børre

    2009-12-01

    Two new interferon stimulated gene 15 (ISG15) family members were identified in a subtractive cDNA library constructed from a mixture of head kidney and spleen of Atlantic cod (Gadus morhua) stimulated with polyinosinic:polycytidylic acid (poly I:C). Two full-length Atlantic cod (Ac) ISG15-2 and AcISG15-3 cDNAs were cloned with rapid amplification of cDNA ends (RACE). The cDNA sequence of AcISG15-2 encodes a 16.9kDa protein and AcISG15-3 encodes a 18.4kDa protein, both of which possess the characteristic structural features of two tandem ubiquitin-like domains and the LRGG motif necessary for conjugation. Furthermore, the AcISG15-3 protein is expressed with a C-terminal extension in common with the human ISG15 protein. Gene expression analysis using quantitative reverse transcriptase PCR (RT-qPCR) showed that AcISG15-1, AcISG15-2, and AcISG15-3 transcripts were up-regulated in head kidney after poly I:C stimulation, suggesting that these proteins may be involved in the cod immune response. However, transient expression of myc-tagged AcISG15 proteins revealed differences in their abilities to form conjugates in vitro. We show that AcISG15-2 forms covalent conjugates to a range of cellular protein as a response to poly I:C, recombinant Atlantic salmon IFNa1 (rSasaIFNa1) and infectious pancreatic necrosis virus (IPNV), whereas conjugation was absent for AcISG15-1 and AcISG15-3. Thus, these results suggest there are three ISG15 homologues in Atlantic cod and that the three proteins may play different roles in innate immunity.

  6. The SPF27 homologue Num1 connects splicing and kinesin 1-dependent cytoplasmic trafficking in Ustilago maydis.

    Science.gov (United States)

    Kellner, Nikola; Heimel, Kai; Obhof, Theresa; Finkernagel, Florian; Kämper, Jörg

    2014-01-01

    The conserved NineTeen protein complex (NTC) is an integral subunit of the spliceosome and required for intron removal during pre-mRNA splicing. The complex associates with the spliceosome and participates in the regulation of conformational changes of core spliceosomal components, stabilizing RNA-RNA- as well as RNA-protein interactions. In addition, the NTC is involved in cell cycle checkpoint control, response to DNA damage, as well as formation and export of mRNP-particles. We have identified the Num1 protein as the homologue of SPF27, one of NTC core components, in the basidiomycetous fungus Ustilago maydis. Num1 is required for polarized growth of the fungal hyphae, and, in line with the described NTC functions, the num1 mutation affects the cell cycle and cell division. The num1 deletion influences splicing in U. maydis on a global scale, as RNA-Seq analysis revealed increased intron retention rates. Surprisingly, we identified in a screen for Num1 interacting proteins not only NTC core components as Prp19 and Cef1, but several proteins with putative functions during vesicle-mediated transport processes. Among others, Num1 interacts with the motor protein Kin1 in the cytoplasm. Similar phenotypes with respect to filamentous and polar growth, vacuolar morphology, as well as the motility of early endosomes corroborate the genetic interaction between Num1 and Kin1. Our data implicate a previously unidentified connection between a component of the splicing machinery and cytoplasmic transport processes. As the num1 deletion also affects cytoplasmic mRNA transport, the protein may constitute a novel functional interconnection between the two disparate processes of splicing and trafficking.

  7. The SPF27 homologue Num1 connects splicing and kinesin 1-dependent cytoplasmic trafficking in Ustilago maydis.

    Directory of Open Access Journals (Sweden)

    Nikola Kellner

    2014-01-01

    Full Text Available The conserved NineTeen protein complex (NTC is an integral subunit of the spliceosome and required for intron removal during pre-mRNA splicing. The complex associates with the spliceosome and participates in the regulation of conformational changes of core spliceosomal components, stabilizing RNA-RNA- as well as RNA-protein interactions. In addition, the NTC is involved in cell cycle checkpoint control, response to DNA damage, as well as formation and export of mRNP-particles. We have identified the Num1 protein as the homologue of SPF27, one of NTC core components, in the basidiomycetous fungus Ustilago maydis. Num1 is required for polarized growth of the fungal hyphae, and, in line with the described NTC functions, the num1 mutation affects the cell cycle and cell division. The num1 deletion influences splicing in U. maydis on a global scale, as RNA-Seq analysis revealed increased intron retention rates. Surprisingly, we identified in a screen for Num1 interacting proteins not only NTC core components as Prp19 and Cef1, but several proteins with putative functions during vesicle-mediated transport processes. Among others, Num1 interacts with the motor protein Kin1 in the cytoplasm. Similar phenotypes with respect to filamentous and polar growth, vacuolar morphology, as well as the motility of early endosomes corroborate the genetic interaction between Num1 and Kin1. Our data implicate a previously unidentified connection between a component of the splicing machinery and cytoplasmic transport processes. As the num1 deletion also affects cytoplasmic mRNA transport, the protein may constitute a novel functional interconnection between the two disparate processes of splicing and trafficking.

  8. Identification and expression analysis of an IL-18 homologue and its alternatively spliced form in rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Zou, Jun; Bird, Steve; Truckle, Jonathan; Bols, Niels; Horne, Mike; Secombes, Chris

    2004-05-01

    A homologue of interleukin 18 has been identified from rainbow trout, Oncorhynchus mykiss. The trout IL-18 gene spans 3.7 kb and consists of six exons and five introns, sharing the same gene organization with its human counterpart. The putative translated protein is 199 amino acids in length with no predicted signal peptide. Analysis of the multiple sequence alignment reveals a conserved ICE cut site, resulting in a mature peptide of 162 amino acids. The trout IL-18 shares 41-45% similarity with known IL-18 molecules and contains an IL-1 family signature motif. It is constitutively expressed in a wide range of tissues including brain, gill, gut, heart, kidney, liver, muscle, skin and spleen. Transcription is not modulated by lipopolysaccharide, poly(I:C) or trout recombinant IL-1beta in primary head kidney leucocyte cultures and RTS-11 cells, a macrophage cell line. However, expression is downregulated by lipopolysaccharide and rIL-1beta in RTG-2 cells, a fibroblast-like cell line. An alternatively spliced form of IL-18 mRNA has also been found and translates into a 182 amino acid protein with a 17 amino acid deletion in the precursor region of the authentic form. This alternatively spliced form is also widely expressed although much lower than the authentic form. Interestingly, its expression is upregulated by lipopolysaccharide and poly(I:C), but is not affected by rIL-1beta in RTG-2 cells. The present study suggests that alternative splicing may play an important role in regulating IL-18 activities in rainbow trout.

  9. Cloning, identification and functional analysis of a β-catenin homologue from Pacific white shrimp, Litopenaeus vannamei.

    Science.gov (United States)

    Zhang, Shuang; Shi, Lili; L, Kai; Li, Haoyang; Wang, Sheng; He, Jianguo; Li, Chaozheng

    2016-07-01

    Wnt signaling is known to control multiple of cellular processes such as cell differentiation, communication, apoptosis and proliferation, and is also reported to play a role during microbial infection. β-catenin is a key regulator of the Wnt signaling cascade. In the present study, we cloned and identified a β-catenin homologue from Litopenaeus vannamei termed Lvβ-catenin. The full-length of Lvβ-catenin transcript was 2797 bp in length within a 2451 bp open reading frame (ORF) that encoded a protein of 816 amino acids. Lvβ-catenin protein was comprised of several characteristic domains such as an N-terminal region of GSK-β consensus phosphorylation site and Coed coil section, a central region of 12 continuous Armadillo/β-Catenin-like repeat (ARM) domains and a C-terminal region. Real-time PCR showed Lvβ-catenin expression was responsive to Vibrio parahaemolyticus and white spot syndrome virus (WSSV) infection. Dual-reporter analysis showed that over-expression of Lvβ-catenin could induce activation of the promoter activities of several antimicrobial peptides (AMPs) such as shrimp PEN4, suggesting that Lvβ-catenin could play a role in regulating the production of AMPs. Knockdown of Lvβ-catenin enhanced the sensitivity of shrimps to V. parahaemolyticus and WSSV challenge, suggesting Lvβ-catenin could play a positive role against bacterial and viral pathogens. In summary, the results presented in this study provided some insights into the function of Wnt/β-catenin of shrimp in regulating AMPs and the host defense against invading pathogens.

  10. Sex-dependent modulation of longevity by two Drosophila homologues of human Apolipoprotein D, GLaz and NLaz.

    Science.gov (United States)

    Ruiz, Mario; Sanchez, Diego; Canal, Inmaculada; Acebes, Angel; Ganfornina, Maria D

    2011-07-01

    Apolipoprotein D (ApoD), a member of the Lipocalin family, is the gene most up-regulated with age in the mammalian brain. Its expression strongly correlates with aging-associated neurodegenerative and metabolic diseases. Two homologues of ApoD expressed in the Drosophila brain, Glial Lazarillo (GLaz) and Neural Lazarillo (NLaz), are known to alter longevity in male flies. However, sex differences in the aging process have not been explored so far for these genes. Here we demonstrate that NLaz alters lifespan in both sexes, but unexpectedly the lack of GLaz influences longevity in a sex-specific way, reducing longevity in males but not in females. While NLaz has metabolic functions similar to ApoD, the regulation of GLaz expression upon aging is the closest to ApoD in the aging brain. A multivariate analysis of physiological parameters relevant to lifespan modulation uncovers both common and specialized functions for the two Lipocalins, and reveals that changes in protein homeostasis account for the observed sex-specific patterns of longevity. The response to oxidative stress and accumulation of lipid peroxides are among their common functions, while the transcriptional and behavioral response to starvation, the pattern of daily locomotor activity, storage of fat along aging, fertility, and courtship behavior differentiate NLaz from GLaz mutants. We also demonstrate that food composition is an important environmental parameter influencing stress resistance and reproductive phenotypes of both Lipocalin mutants. Since ApoD shares many properties with the common ancestor of invertebrate Lipocalins, we must benefit from this global comparison with both GLaz and NLaz to understand the complex functions of ApoD in mammalian aging and neurodegeneration.

  11. MutS homologue hMSH5: recombinational DSB repair and non-synonymous polymorphic variants.

    Science.gov (United States)

    Wu, Xiling; Xu, Yang; Feng, Katey; Tompkins, Joshua D; Her, Chengtao

    2013-01-01

    Double-strand breaks (DSBs) constitute the most deleterious form of DNA lesions that can lead to genome alterations and cell death, and the vast majority of DSBs arise pathologically in response to DNA damaging agents such as ionizing radiation (IR) and chemotherapeutic agents. Recent studies have implicated a role for the human MutS homologue hMSH5 in homologous recombination (HR)-mediated DSB repair and the DNA damage response. In the present study, we show that hMSH5 promotes HR-based DSB repair, and this property resides in the carboxyl-terminal portion of the protein. Our results demonstrate that DSB-triggered hMSH5 chromatin association peaks at the proximal regions of the DSB and decreases gradually with increased distance from the break. Furthermore, the DSB-triggered hMSH5 chromatin association is preceded by and relies on the assembly of hMRE11 and hRad51 at the proximal regions of the DSB. Lastly, the potential effects of hMSH5 non-synonymous variants (L85F, Y202C, V206F, R351G, L377F, and P786S) on HR and cell survival in response to DSB-inducing anticancer agents have been analyzed. These experiments show that the expression of hMSH5 variants elicits different survival responses to anticancer drugs cisplatin, bleomycin, doxorubicin and camptothecin. However, the effects of hMSH5 variants on survival responses to DSB-inducing agents are not directly correlated to their effects exerted on HR-mediated DSB repair, suggesting that the roles of hMSH5 variants in the processes of DNA damage response and repair are multifaceted.

  12. The immune system GTPase GIMAP6 interacts with the Atg8 homologue GABARAPL2 and is recruited to autophagosomes.

    Directory of Open Access Journals (Sweden)

    John C Pascall

    Full Text Available The GIMAPs (GTPases of the immunity-associated proteins are a family of small GTPases expressed prominently in the immune systems of mammals and other vertebrates. In mammals, studies of mutant or genetically-modified rodents have indicated important roles for the GIMAP GTPases in the development and survival of lymphocytes. No clear picture has yet emerged, however, of the molecular mechanisms by which they perform their function(s. Using biotin tag-affinity purification we identified a major, and highly specific, interaction between the human cytosolic family member GIMAP6 and GABARAPL2, one of the mammalian homologues of the yeast autophagy protein Atg8. Chemical cross-linking studies performed on Jurkat T cells, which express both GIMAP6 and GABARAPL2 endogenously, indicated that the two proteins in these cells readily associate with one another in the cytosol under normal conditions. The GIMAP6-GABARAPL2 interaction was disrupted by deletion of the last 10 amino acids of GIMAP6. The N-terminal region of GIMAP6, however, which includes a putative Atg8-family interacting motif, was not required. Over-expression of GIMAP6 resulted in increased levels of endogenous GABARAPL2 in cells. After culture of cells in starvation medium, GIMAP6 was found to localise in punctate structures with both GABARAPL2 and the autophagosomal marker MAP1LC3B, indicating that GIMAP6 re-locates to autophagosomes on starvation. Consistent with this finding, we have demonstrated that starvation of Jurkat T cells results in the degradation of GIMAP6. Whilst these findings raise the possibility that the GIMAPs play roles in the regulation of autophagy, we have been unable to demonstrate an effect of GIMAP6 over-expression on autophagic flux.

  13. Characterization of interleukin-8 receptors in non-human primates

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, V.; Coto, E.; Gonzalez-Roces, S.; Lopez-Larrea, C. [Hospital Central de Asturias, Oviedo (Spain)] [and others

    1996-09-01

    Interleukin-8 is a chemokine with a potent neutrophil chemoatractant activity. In humans, two different cDNAs encoding human IL8 receptors designated IL8RA and IL8RB have been cloned. IL8RA binds IL8, while IL8RB binds IL8 as well as other {alpha}-chemokines. Both human IL8Rs are encoded by two genes physically linked on chromosome 2. The IL8RA and IL8RB genes have open reading frames (ORF) lacking introns. By direct sequencing of the polymerase chain reaction products, we sequenced the IL8R genes of cell lines from four non-human primates: chimpanzee, gorilla, orangutan, and macaca. The IL8RB encodes an ORF in the four non-human primates, showing 95%-99% similarity to the human IL8RB sequence. The IL8RA homologue in gorilla and chimpanzee consisted of two ORF 98%-99% identical to the human sequence. The macaca and orangutan IL8RA homologues are pseudogenes: a 2 base pair insertion generated a sequence with several stop codons. In addition, we describe the physical linkage of these genes in the four non-human primates and discuss the evolutionary implications of these findings. 25 refs., 5 figs., 3 tabs.

  14. Characterization of Steroid Receptor RNA Activator Protein Function in Modulating the Estrogen Signaling Pathway

    Science.gov (United States)

    2008-03-01

    upstream of the firefly luciferase cDNA) and 0.1 lg of renilla luciferase reporter vector (Promega, Madison, WI) using the lipo - fectamine reagent...regulatory factor 1 JUN + V-jun sarcoma virus 17 oncogene homologue JUN B + JUNB proto-oncogene LDB1 ++ LIM domain binding 1 LHX2 ++ LIM homeobox 2...0.021 ESR2 Estrogen receptor 2 (ER beta) 1.73 331 0.029 STC2 Stanniocalcin 2 1.20 230 0.009 JUN V-jun sarcoma virus 17 oncogene homolog (avian

  15. Molecular cloning of chicken FTZ-F1-related orphan receptors.

    Science.gov (United States)

    Kudo, T; Sutou, S

    1997-09-15

    FTZ-F1 is a member of the orphan nuclear receptors, which belongs to the steroid hormone receptor superfamily, and plays a role in the blastoderm and nervous system development in Drosophila. Recently, several FTZ-F1 family genes have been cloned in several species. SF-1/Ad4BPs have been identified as master regulators controlling steroidogenic P-450 genes in mammals and are considered to be the mammalian homologues of FTZ-F1. Moreover, SF-1/Ad4BP plays a critical role in the sexual differentiation of gonads in mammals. In vertebrates, except for mammals, the functional homologue of SF-1/Ad4BP has not been identified before. Herein, we cloned two chicken cDNAs (OR2.0 and OR2.1), which encode putative FTZ-F1 family receptors, by reverse transcriptase-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). OR2.1 consists of 3255 bp, is expressed in the adrenal glands and gonads, and is considered to be the chicken counterpart of mammalian SF-1/Ad4BP. However, OR2.0 consists of 2945 bp, is expressed in the livers and the adrenal glands, and is considered to be the chicken counterpart of mouse LRH-1, which is a member of the FTZ-F1 family in mammals.

  16. Cloning and expression of the human N-methyl-D-aspartate receptor subunit NR3A

    DEFF Research Database (Denmark)

    Eriksson, Maria; Nilsson, Anna; Froelich-Fabre, Susanne

    2002-01-01

    Native N-methyl-D-aspartate (NMDA) receptors are heteromeric assemblies of four or five subunits. The NMDA receptor subunits, NR1, NR2A, NR2B, NR2C, and NR2D have been cloned in several species, including man. The NR3A subunit, which in rodents is predominantly expressed during early development......, seems to function by reducing the NMDA receptor response. The human homologue to the rat NR3A, however, had not been cloned. In order to study the functions of the human NR3A (hNR3A), we have cloned and sequenced the hNR3A. It was found to share 88% of the DNA sequence with the rat gene, corresponding...

  17. Cloning and expression of the human N-methyl-D-aspartate receptor subunit NR3A

    DEFF Research Database (Denmark)

    Eriksson, Maria; Nilsson, Anna; Froelich-Fabre, Susanne

    2002-01-01

    Native N-methyl-D-aspartate (NMDA) receptors are heteromeric assemblies of four or five subunits. The NMDA receptor subunits, NR1, NR2A, NR2B, NR2C, and NR2D have been cloned in several species, including man. The NR3A subunit, which in rodents is predominantly expressed during early development......, seems to function by reducing the NMDA receptor response. The human homologue to the rat NR3A, however, had not been cloned. In order to study the functions of the human NR3A (hNR3A), we have cloned and sequenced the hNR3A. It was found to share 88% of the DNA sequence with the rat gene, corresponding...

  18. Domain-based identification and analysis of glutamate receptor ion channels and their relatives in prokaryotes.

    Directory of Open Access Journals (Sweden)

    Mao-Feng Ger

    Full Text Available Voltage-gated and ligand-gated ion channels are used in eukaryotic organisms for the purpose of electrochemical signaling. There are prokaryotic homologues to major eukaryotic channels of these sorts, including voltage-gated sodium, potassium, and calcium channels, Ach-receptor and glutamate-receptor channels. The prokaryotic homologues have been less well characterized functionally than their eukaryotic counterparts. In this study we identify likely prokaryotic functional counterparts of eukaryotic glutamate receptor channels by comprehensive analysis of the prokaryotic sequences in the context of known functional domains present in the eukaryotic members of this family. In particular, we searched the nonredundant protein database for all proteins containing the following motif: the two sections of the extracellular glutamate binding domain flanking two transmembrane helices. We discovered 100 prokaryotic sequences containing this motif, with a wide variety of functional annotations. Two groups within this family have the same topology as eukaryotic glutamate receptor channels. Group 1 has a potassium-like selectivity filter. Group 2 is most closely related to eukaryotic glutamate receptor channels. We present analysis of the functional domain architecture for the group of 100, a putative phylogenetic tree, comparison of the protein phylogeny with the corresponding species phylogeny, consideration of the distribution of these proteins among classes of prokaryotes, and orthologous relationships between prokaryotic and human glutamate receptor channels. We introduce a construct called the Evolutionary Domain Network, which represents a putative pathway of domain rearrangements underlying the domain composition of present channels. We believe that scientists interested in ion channels in general, and ligand-gated ion channels in particular, will be interested in this work. The work should also be of interest to bioinformatics researchers who are

  19. Expression of achaete-scute homologue 2 and its correlation with serum globulin in patients with chronic hepatitis C

    Directory of Open Access Journals (Sweden)

    ZHAO Jieru

    2017-01-01

    Full Text Available ObjectiveTo investigate the correlation between peripheral CD4+CXCR5+PD-1+T cells and serum globulin in chronic hepatitis C (CHC patients and health volunteers, and to clarify the role of the expression of achaete-scute homologue 2 (Ascl2, the transcription factor in peripheral follicular helper T (Tfh cells, in the process of chronic hepatitis C virus (HCV infection. MethodsA total of 46 previously untreated CHC patients who were admitted to Tangdu Hospital, Fourth Military Medical University, from October 2015 to May 2016 were enrolled, and 32 healthy laboratory technicians and persons who underwent physical examination in our hospital were enrolled as healthy control group. Flow cytometry was used to measure the percentage of Tfh cells in CD4+ T cells and the change in its subset (CD4+CXCR5+PD-1+ T cells in peripheral blood, an automatic biochemical analyzer was used to measure the serum globulin level, and real-time PCR was used to measure the mRNA expression of Ascl2 in Tfh cells. The association between the changes in these parameters and HCV infection was analyzed. The independent samples t-test was used for the comparison of continuous data between groups, and the Pearson correlation analysis was also performed. ResultsIn CHC patients, peripheral Tfh cells were positively correlated with B lymphocytes (r=0.582 3, P=0.011 2, peripheral B lymphocytes were positively correlated with globulin (r=0.450 9, P=0.031 6, and Tfh cells were positively correlated with globulin (r=0.583 5, P=0.038 3. CHC patients had significantly higher mRNA expression of Ascl2 in peripheral Tfh cells than the healthy control group (1.019±0.666 vs 6.437±5.776, t=4.552, P=0.001 9. ConclusionTfh cells may be involved in the production of serum globulin in CHC patients, and the transcription factor Ascl2 may participate in the differentiation and development of Tfh cells in the process of HCV infection.

  20. A homologue of the defender against the apoptotic death gene (dad1) in UV-exposed Chlamydomonas cells is downregulated with the onset of programmed cell death

    Indian Academy of Sciences (India)

    Swati Moharikar; Jacinta S D’souza; Basuthkar J Rao

    2007-03-01

    We report here the isolation of a homologue of the potential anti-apoptotic gene, defender against apoptotic death (dad1) from Chlamydomonas reinhardtii cells. Using polymerase chain reaction (PCR), we investigated its expression in the execution process of programmed cell death (PCD) in UV-C exposed dying C. reinhardtii cells. Reverse-transcriptase (RT)-PCR showed that C. reinhardtii dad1 amplification was drastically reduced in UV-C exposed dying C. reinhardtii cells. We connect the downregulation of dad1 with the upregulation of apoptosis protease activating factor-1 (APAF-1) and the physiological changes that occur in C. reinhardtii cells upon exposure to 12 J/m2 UV-C in order to show a reciprocal relationship between proapoptotic and inhibitor of apoptosis factors. The temporal changes indicate a correlation between the onset of cell death and dad1 downregulation. The sequence of the PCR product of the cDNA encoding the dad1 homologue was aligned with the annotated dad1 (C_20215) from the Chlamydomonas database (http://genome.jgi-psf.org:8080/annotator/servlet/jgi.annotation.Annotation?pDb=chlre2); Annotation?pDb=chlre2); this sequence was found to show 100% identity, both at the nucleotide and amino acid level. The 327 bp transcript showed an open reading frame of 87 amino acid residues. The deduced amino acid sequence of the putative C. reinhardtii DAD1 homologue showed 54% identity with Oryza sativa, 56% identity with Drosophila melanogaster, 66% identity with Xenopus laevis, and 64% identity with Homo sapiens, Sus scrofa, Gallus gallus, Rattus norvegicus and Mus musculus.

  1. Cloning of the rhesus lymphocryptovirus viral capsid antigen and Epstein-Barr virus-encoded small RNA homologues and use in diagnosis of acute and persistent infections.

    Science.gov (United States)

    Rao, P; Jiang, H; Wang, F

    2000-09-01

    Epstein-Barr virus (EBV) is the most common cause of infectious mononucleosis and is associated with the development of several human malignancies. A closely related herpesvirus in the same lymphocryptovirus (LCV) genera as EBV naturally infects rhesus monkeys and provides an important animal model for studying EBV pathogenesis. We cloned the small viral capsid antigen (sVCA) homologue from the rhesus LCV and developed a peptide enzyme-linked immunosorbent assay (ELISA) to determine whether epitopes in the rhesus LCV sVCA are a reliable indicator of rhesus LCV infection. In order to define a "gold standard" for rhesus LCV infection, we also cloned the EBV-encoded small RNA 1 (EBER1) and EBER2 homologues from rhesus LCV and developed a reverse transcription (RT)-PCR assay to detect persistent LCV infection in rhesus monkey peripheral blood lymphocytes. Animals from a conventional and a hand-reared colony were studied to compare the prevalence of rhesus LCV infection in the two groups. There was a 100% correlation between the peptide ELISA and EBER RT-PCR results for rhesus LCV infection. In addition, specificity for LCV infection and exclusion of potential cross-reactivity to the rhesus rhadinovirus sVCA homologue could be demonstrated using sera from experimentally infected animals. These studies establish two novel assays for reliable diagnosis of acute and persistent rhesus LCV infections. The rhesus LCV sVCA peptide ELISA provides a sensitive and reliable assay for routine screening, and these studies of the hand-reared colony confirm the feasibility of raising rhesus LCV-naive animals.

  2. Analysis of a homologue of the adducin head gene which is a potential target for the Dictyostelium STAT protein Dd-STATa.

    Science.gov (United States)

    Aoshima, Ryota; Hiraoka, Rieko; Shimada, Nao; Kawata, Takefumi

    2006-01-01

    A Dd-STATa-null mutant, which is defective in expression of a Dictyostelium homologue of the metazoan STAT (signal transducers and activators of transcription) proteins, fails to culminate and this phenotype correlates with the loss of expression of various prestalk (pst) genes. An EST clone, SSK395, encodes a close homologue of the adducin amino-terminal head domain and harbors a putative actin-binding domain. We fused promoter fragments of the cognate gene, ahhA (adducin head homologue A), to a lacZ reporter and determined their expression pattern. The proximal promoter region is necessary for the expression of ahhA at an early (pre-aggregative) stage of development and this expression is Dd-STATa independent. The distal promoter region is necessary for expression at later stages of development in pstA cells, of the slug and in upper cup and pstAB cells during culmination. The distal region is partly Dd-STATa-dependent. The ahhA-null mutant develops almost normally until culmination, but it forms slanting culminants that tend to collapse on to the substratum. The mutant also occasionally forms fruiting bodies with swollen papillae and with constrictions in the prestalk region. The AhhA protein localizes to the stalk tube entrance and also to the upper cup cells and in cells at or near to the constricted region where an F-actin ring is localized. These findings suggest that Dd-STATa regulates culmination and may be necessary for straight downward elongation of the stalk, via the putative actin-binding protein AhhA.

  3. The nuclear receptor gene family in the Pacific oyster, Crassostrea gigas, contains a novel subfamily group.

    Science.gov (United States)

    Vogeler, Susanne; Galloway, Tamara S; Lyons, Brett P; Bean, Tim P

    2014-05-15

    Nuclear receptors are a superfamily of transcription factors important in key biological, developmental and reproductive processes. Several of these receptors are ligand- activated and through their ability to bind endogenous and exogenous ligands, are potentially vulnerable to xenobiotics. Molluscs are key ecological species in defining aquatic and terrestrial habitats and are sensitive to xenobiotic compounds in the environment. However, the understanding of nuclear receptor presence, function and xenobiotic disruption in the phylum Mollusca is limited. Here, forty-three nuclear receptor sequences were mined from the genome of the Pacific oyster, Crassostrea gigas. They include members of NR0-NR5 subfamilies, notably lacking any NR6 members. Phylogenetic analyses of the oyster nuclear receptors have been conducted showing the presence of a large novel subfamily group not previously reported, which is named NR1P. Homologues to all previous identified nuclear receptors in other mollusc species have also been determined including the putative heterodimer partner retinoid X receptor, estrogen receptor and estrogen related receptor. C. gigas contains a highly diverse set of nuclear receptors including a novel NR1 group, which provides important information on presence and evolution of this transcription factor superfamily in invertebrates. The Pacific oyster possesses two members of NR3, the sex steroid hormone receptor analogues, of which there are 9 in humans. This provides increasing evidence that steroid ligand specific expansion of this family is deuterostome specific. This new knowledge on divergence and emergence of nuclear receptors in C. gigas provides essential information for studying regulation of molluscan gene expression and the potential effects of xenobiotics.

  4. Crystal Structure of a NifS Homologue CsdB from Escherichia coli (MOLECULAR BIOLOGY AND INFORMATION-Biopolymer Structure)

    OpenAIRE

    Fujii, Tomomi; Hata, Yasuo

    2001-01-01

    Escherichia coli CsdB is a dimeric NifS-homologue belonging to the fold-type I family of PLPdependent enzymes, and catalyzes the decomposition of L-selenocysteine into selenium and L-alanine with specificity higher than that for a substrate of cysteine. The structure of the enzyme has been determined at 2.8 A resolution by an X-ray crystallographic method. The subunit of CsdB comprises a large domain, a small domain, and an N-terminal segment. A remarkable structural feature of CsdB is that a...

  5. Snake venom toxins. The amino acid sequence of toxin Vi2, a homologue of pancreatic trypsin inhibitor, from Dendroaspis polylepis polylepis (black mamba) venom.

    Science.gov (United States)

    Strydom, D J

    1977-04-25

    The amino acid sequence of venom component Vi2, a protein of low toxicity from Dendroaspis polylepis polylepis venom was determined by automatic sequence analysis in combination with sequence studies on tryptic peptides. This protein, the most retarded fraction of this venom on a cation-exchange resin, is a homologue of bovine pancreatic trypsin inhibitor consisting of a single chain of 57 amino acid residues containing six half-cystine residues. The active site lysyl residue of bovine trypsin inhibitor is conserved in Vi2 although large differences are found in the rest of the molecule.

  6. A Novel Intronic Peroxisome Proliferator-activated Receptor γ Enhancer in the Uncoupling Protein (UCP) 3 Gene as a Regulator of Both UCP2 and -3 Expression in Adipocytes*

    OpenAIRE

    2010-01-01

    Uncoupling Proteins (UCPs) are integral ion channels residing in the inner mitochondrial membrane. UCP2 is ubiquitously expressed, while UCP3 is found primarily in muscles and adipose tissue. Although the exact molecular mechanism of action is controversial, it is generally agreed that both homologues function to facilitate mitochondrial fatty acid oxidation. UCP2 and -3 expression is activated by the peroxisome proliferator-activated receptors (PPARs), but so far no PPAR response element has...

  7. Allosteric activation mechanism of the cys-loop receptors

    Institute of Scientific and Technical Information of China (English)

    Yong-chang CHANG; Wen WU; Jian-liang ZHANG; Yao HUANG

    2009-01-01

    Binding of a neurotransmitter to its ionotropic receptor opens a distantly located ion channel, a process termed allosteric activation. Here we review recent advances in the molecular mechanism by which the cys-loop receptors are activated with emphasis on the best studied nicotinic acetylcholine receptors (nAChRs). With a combination of affinity labeling, mutagenesis, electrophysiology, kinetic modeling, electron microscopy (EM), and crystal structure analysis, the allosteric activation mechanism is emerging. Specifically, the binding domain and gating domain are interconnected by an allosteric activation network. Agonist binding induces conformational changes, resulting in the rotation of a β sheet of amino-terminal domain and outward movement of loop 2, loop F, and cys-loop, which are coupled to the M2-M3 linker to pull the channel to open. However, there are still some controversies about the movement of the channel-lining domain M2. Nine angstrom resolution EM structure of a nAChR imaged in the open state suggests that channel opening is the result of rotation of the M2 domain. In contrast, recent crystal structures of bacterial homologues of the cys-loop receptor family in apparently open state have implied an M2 tilting model with pore dilation and quaternary twist of the whole pentameric receptor. An elegant study of the nAChR using protonation scanning of M2 domain supports a similar pore dilation activation mechanism with minimal rotation of M2. This remains to be validated with other approaches including high resolution structure determination of the mammalian cys-loop receptors in the open state.

  8. Equine herpesvirus 1 gene 12, the functional homologue of herpes simplex virus VP16, transactivates via octamer sequences in the equine herpesvirus IE gene promoter.

    Science.gov (United States)

    Elliott, G; O'Hare, P

    1995-10-20

    The HSV-1 transactivator of immediate-early (IE) gene expression, VP16, has several functional homologues among the alphaherpesviruses which have not yet been extensively studied in relation to their modes of action. To date, nothing is known of the exact sites or mechanism of interaction of the equine herpesvirus type 1 (EHV-1) homologue, the gene 12 protein, with the EHV-1 IE promoter. We show that the gene 12 protein utilises the promoter proximal region of the IE gene to induce activation and identify four potential octamer DNA binding sites within that region. Although there was divergence from its consensus, Oct-1 bound to each of these sites in an in vitro complex formation assay, and in the presence of the gene 12 product a second complex of slower migration, which was also dependent on Oct-1, was detected. When each site was inserted into a basal promoter, two conferred activation by gene 12 with a resulting increase in expression of up to 50-fold compared to basal levels. These results show that, despite the differences between the two proteins, the mechanism of interaction of the gene 12 protein with its target is analogous to that of VP16.

  9. Comparison of the regulation, metabolic functions, and roles in virulence of the glyceraldehyde-3-phosphate dehydrogenase homologues gapA and gapB in Staphylococcus aureus.

    Science.gov (United States)

    Purves, Joanne; Cockayne, Alan; Moody, Peter C E; Morrissey, Julie A

    2010-12-01

    The Gram-positive bacterium Staphylococcus aureus contains two glyceraldehyde-3-phosphate dehydrogenase (GAPDH) homologues known as GapA and GapB. GapA has been characterized as a functional GAPDH protein, but currently there is no biological evidence for the role of GapB in metabolism in S. aureus. In this study we show through a number of complementary methods that S. aureus GapA is essential for glycolysis while GapB is essential in gluconeogenesis. These proteins are reciprocally regulated in response to glucose concentrations, and both are influenced by the glycolysis regulator protein GapR, which is the first demonstration of the role of this regulator in S. aureus and the first indication that GapR homologues control genes other than those within the glycolytic operon. Furthermore, we show that both GapA and GapB are important in the pathogenesis of S. aureus in a Galleria mellonella model of infection, showing for the first time in any bacteria that both glycolysis and gluconeogenesis have important roles in virulence.

  10. DUF538 protein super family is predicted to be the potential homologue of bactericidal/permeability-increasing protein in plant system.

    Science.gov (United States)

    Gholizadeh, Ashraf; Kohnehrouz, Samira Baghban

    2013-03-01

    DUF538 protein super family includes a number of plant proteins that their role is not yet clear. These proteins have been frequently reported to be expressed in plants under various stressful stimuli such as bacteria and elicitors. In order to further understand about this protein family we utilized bioinformatics tools to analyze its structure in details. As a result, plants DUF538 was predicted to be the partial structural homologue of BPI (bactericidal/permeability increasing) proteins in mammalian innate immune system that provides the first line of defense against different pathogens including bacteria, fungi, viruses and parasites. Moreover, on the base of the experimental data, it was identified that exogenously applied purified fused product of Celosia DUF538 affects the bacterial growth more possibly similar to BPI through the binding to the bacterial membranes. In conclusion, as the first ever time report, we nominated DUF538 protein family as the potential structural and functional homologue of BPI protein in plants, providing a basis to study the novel functions of this protein family in the biological systems in the future.

  11. Two plant bacteria, S. meliloti and Ca. Liberibacter asiaticus, share functional znuABC homologues that encode for a high affinity zinc uptake system.

    Directory of Open Access Journals (Sweden)

    Cheryl M Vahling-Armstrong

    Full Text Available The Znu system, encoded for by znuABC, can be found in multiple genera of bacteria and has been shown to be responsible for the import of zinc under low zinc conditions. Although this high-affinity uptake system is known to be important for both growth and/or pathogenesis in bacteria, it has not been functionally characterized in a plant-associated bacterium. A single homologue of this system has been identified in the plant endosymbiont, Sinorhizobium meliloti, while two homologous systems were found in the destructive citrus pathogen, Candidatus Liberibacter asiaticus. To understand the role of these protein homologues, a complementation assay was devised allowing the individual genes that comprise the system to be assayed independently for their ability to reinstate a partially-inactivated Znu system. Results from the assays have demonstrated that although all of the genes from S. meliloti were able to restore activity, only one of the two Ca. Liberibacter asiaticus encoded gene clusters contained genes that were able to functionally complement the system. Additional analysis of the gene clusters reveals that distinct modes of regulation may also exist between the Ca. Liberibacter asiaticus and S. meliloti import systems despite the intracellular-plant niche common to both of these bacteria.

  12. Comparison of the Regulation, Metabolic Functions, and Roles in Virulence of the Glyceraldehyde-3-Phosphate Dehydrogenase Homologues gapA and gapB in Staphylococcus aureus▿

    Science.gov (United States)

    Purves, Joanne; Cockayne, Alan; Moody, Peter C. E.; Morrissey, Julie A.

    2010-01-01

    The Gram-positive bacterium Staphylococcus aureus contains two glyceraldehyde-3-phosphate dehydrogenase (GAPDH) homologues known as GapA and GapB. GapA has been characterized as a functional GAPDH protein, but currently there is no biological evidence for the role of GapB in metabolism in S. aureus. In this study we show through a number of complementary methods that S. aureus GapA is essential for glycolysis while GapB is essential in gluconeogenesis. These proteins are reciprocally regulated in response to glucose concentrations, and both are influenced by the glycolysis regulator protein GapR, which is the first demonstration of the role of this regulator in S. aureus and the first indication that GapR homologues control genes other than those within the glycolytic operon. Furthermore, we show that both GapA and GapB are important in the pathogenesis of S. aureus in a Galleria mellonella model of infection, showing for the first time in any bacteria that both glycolysis and gluconeogenesis have important roles in virulence. PMID:20876289

  13. Analysis of linear alkylbenzene sulfonate homologues in environmental water samples by mixed admicelle-based extraction and liquid chromatography/mass spectrometry.

    Science.gov (United States)

    Lunar, Loreto; Rubio, Soledad; Pérez-Bendito, Dolores

    2006-07-01

    Hemimicelles and admicelles of cetyltrimethylammonium bromide (CTAB) and cetylpyridinium chloride (CPC), adsorbed onto silica, were tested as sorbents for the solid phase extraction (SPE) of linear alkylbenzene sulfonate (LAS) homologues from environmental water samples. LASs were quantitatively retained on both surfactants due to high hydrophobic and ionic interactions, which led to the formation of analyte-extractant mixed aggregates. Parameters affecting the SPE of LASs were optimised. Recoveries of analytes from wastewater influent and effluent and river water samples ranged between 86 and 110%. Combination of SPE with liquid chromatography/mass spectrometry provided detection limits for the different LAS homologues of about 4 ng L(-1). The precision of the method, expressed as relative standard deviation, ranged from 5 to 9%. The method was applied to the analysis of LASs in wastewater and river samples using sample volumes between 10 and 25 mL. The LAS concentrations found ranged from 9 to 503 microg L(-1). No cleaning step was required to get accurate results.

  14. Molecular evolution of a chordate specific family of G protein-coupled receptors

    Directory of Open Access Journals (Sweden)

    Leese Florian

    2011-08-01

    Full Text Available Abstract Background Chordate evolution is a history of innovations that is marked by physical and behavioral specializations, which led to the development of a variety of forms from a single ancestral group. Among other important characteristics, vertebrates obtained a well developed brain, anterior sensory structures, a closed circulatory system and gills or lungs as blood oxygenation systems. The duplication of pre-existing genes had profound evolutionary implications for the developmental complexity in vertebrates, since mutations modifying the function of a duplicated protein can lead to novel functions, improving the evolutionary success. Results We analyzed here the evolution of the GPRC5 family of G protein-coupled receptors by comprehensive similarity searches and found that the receptors are only present in chordates and that the size of the receptor family expanded, likely due to genome duplication events in the early history of vertebrate evolution. We propose that a single GPRC5 receptor coding gene originated in a stem chordate ancestor and gave rise by duplication events to a gene family comprising three receptor types (GPRC5A-C in vertebrates, and a fourth homologue present only in mammals (GPRC5D. Additional duplications of GPRC5B and GPRC5C sequences occurred in teleost fishes. The finding that the expression patterns of the receptors are evolutionarily conserved indicates an important biological function of these receptors. Moreover, we found that expression of GPRC5B is regulated by vitamin A in vivo, confirming previous findings that linked receptor expression to retinoic acid levels in tumor cell lines and strengthening the link between the receptor expression and the development of a complex nervous system in chordates, known to be dependent on retinoic acid signaling. Conclusions GPRC5 receptors, a class of G protein-coupled receptors with unique sequence characteristics, may represent a molecular novelty that helped non

  15. Auxiliary Subunits: Shepherding AMPA Receptors to the Plasma Membrane

    Directory of Open Access Journals (Sweden)

    Simon C. Haering

    2014-08-01

    Full Text Available Ionotropic glutamate receptors (iGluRs are tetrameric ligand-gated cation channels that mediate excitatory signal transmission in the central nervous system (CNS of vertebrates. The members of the iGluR subfamily of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA receptors (AMPARs mediate most of the fast excitatory signal transmission, and their abundance in the postsynaptic membrane is a major determinant of the strength of excitatory synapses. Therefore, regulation of AMPAR trafficking to the postsynaptic membrane is an important constituent of mechanisms involved in learning and memory formation, such as long-term potentiation (LTP and long-term depression (LTD. Auxiliary subunits play a critical role in the facilitation and regulation of AMPAR trafficking and function. The currently identified auxiliary subunits of AMPARs are transmembrane AMPA receptor regulatory proteins (TARPs, suppressor of lurcher (SOL, cornichon homologues (CNIHs, synapse differentiation-induced gene I (SynDIG I, cysteine-knot AMPAR modulating proteins 44 (CKAMP44, and germ cell-specific gene 1-like (GSG1L protein. In this review we summarize our current knowledge of the modulatory influence exerted by these important but still underappreciated proteins.

  16. A study of anaerobic biodegradation of pure homologue and isomers of linear alkylbenzene sulphonate (LAS) in batch digesters; Estudio de la biodegradacion anaerobia de homologos e isomeros puros de alquibenceno sulfonatos lineales (LAS) en digestores discontinuos

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M. T.; Campos, E.; Illan, P.; Dalman, M.; Sanchez-Leal, J.

    2005-07-01

    In the present work the effect of different structural parameters on the anaerobic degradation of the LAS molecule has been studied. so, the effect both of the alkyl chain length and the phenyl position on the anaerobic degradation of the LAS molecule have been investigated. The behaviour of the individual homologues and isomers was studied applying discontinuous anaerobic tests (ECETOC-28). Sludge from the anaerobic digester of the waste water treatment plant of Manresa (Barcelona) was used as bacterial inoculum source. All the LAS homologues showed a poor primary biodegradation. In addition, no effect of the LAS isomer type was found on the anaerobic degradation kinetics. (Author) 6 refs.

  17. Zebrafish M2 muscarinic acetylcholine receptor: cloning, pharmacological characterization, expression patterns and roles in embryonic bradycardia

    OpenAIRE

    Hsieh, Dennis Jine-Yuan; Liao, Ching-Fong

    2002-01-01

    A zebrafish M2 muscarinic acetylcholine receptor (mAChR) gene was cloned. It encodes 495 amino acids in a single exon. The derived amino acid sequence is 73.5% identical to its human homologue.Competitive binding studies of the zebrafish M2 receptor and [3H]-NMS gave negative log dissociation constants (pKi) for each antagonist as follows: atropine (9.16)>himbacine (8.05)⩾4-DAMP (7.83)>AF-DX 116 (7.26)⩾pirenzepine (7.18)⩾tropicamide (6.97)⩾methoctramine (6.82)⩾p-F-HHSiD (6.67)>carbachol (5.20...

  18. The androgen receptor and estrogen receptor

    NARCIS (Netherlands)

    Oosterkamp, H.M.; Bernards, R.A.

    2002-01-01

    The androgen receptor (AR) and the estrogen receptors (ER) are members of the nuclear receptor (NR) family. These NRs are distinguished from the other transcription factors by their ability to control gene expression upon ligand binding (steroids, retinoids, thyroid hormone, vitamin D, fatty acids,

  19. The TIR Homologue Lies near Resistance Genes in Staphylococcus aureus, Coupling Modulation of Virulence and Antimicrobial Susceptibility.

    Directory of Open Access Journals (Sweden)

    Sabine Patot

    2017-01-01

    Full Text Available Toll/interleukin-1 receptor (TIR domains in Toll-like receptors are essential for initiating and propagating the eukaryotic innate immune signaling cascade. Here, we investigate TirS, a Staphylococcus aureus TIR mimic that is part of a novel bacterial invasion mechanism. Its ectopic expression in eukaryotic cells inhibited TLR signaling, downregulating the NF-kB pathway through inhibition of TLR2, TLR4, TLR5, and TLR9. Skin lesions induced by the S. aureus knockout tirS mutant increased in a mouse model compared with wild-type and restored strains even though the tirS-mutant and wild-type strains did not differ in bacterial load. TirS also was associated with lower neutrophil and macrophage activity, confirming a central role in virulence attenuation through local inflammatory responses. TirS invariably localizes within the staphylococcal chromosomal cassettes (SCC containing the fusC gene for fusidic acid resistance but not always carrying the mecA gene. Of note, sub-inhibitory concentration of fusidic acid increased tirS expression. Epidemiological studies identified no link between this effector and clinical presentation but showed a selective advantage with a SCCmec element with SCC fusC/tirS. Thus, two key traits determining the success and spread of bacterial infections are linked.

  20. The TIR Homologue Lies near Resistance Genes in Staphylococcus aureus, Coupling Modulation of Virulence and Antimicrobial Susceptibility

    Science.gov (United States)

    Patot, Sabine; RC Imbert, Paul; Baude, Jessica; Martins Simões, Patricia; Campergue, Jean-Baptiste; Louche, Arthur; Bès, Michèle; Tristan, Anne; Laurent, Frédéric; Fischer, Adrien; Schrenzel, Jacques; François, Patrice; Lina, Gérard

    2017-01-01

    Toll/interleukin-1 receptor (TIR) domains in Toll-like receptors are essential for initiating and propagating the eukaryotic innate immune signaling cascade. Here, we investigate TirS, a Staphylococcus aureus TIR mimic that is part of a novel bacterial invasion mechanism. Its ectopic expression in eukaryotic cells inhibited TLR signaling, downregulating the NF-kB pathway through inhibition of TLR2, TLR4, TLR5, and TLR9. Skin lesions induced by the S. aureus knockout tirS mutant increased in a mouse model compared with wild-type and restored strains even though the tirS-mutant and wild-type strains did not differ in bacterial load. TirS also was associated with lower neutrophil and macrophage activity, confirming a central role in virulence attenuation through local inflammatory responses. TirS invariably localizes within the staphylococcal chromosomal cassettes (SCC) containing the fusC gene for fusidic acid resistance but not always carrying the mecA gene. Of note, sub-inhibitory concentration of fusidic acid increased tirS expression. Epidemiological studies identified no link between this effector and clinical presentation but showed a selective advantage with a SCCmec element with SCC fusC/tirS. Thus, two key traits determining the success and spread of bacterial infections are linked. PMID:28060920

  1. Birch pollen-related food allergy to legumes: identification and characterization of the Bet v 1 homologue in mungbean (Vigna radiata), Vig r 1.

    Science.gov (United States)

    Mittag, D; Vieths, S; Vogel, L; Wagner-Loew, D; Starke, A; Hunziker, P; Becker, W-M; Ballmer-Weber, B K

    2005-08-01

    Recently allergic reactions to legumes mediated by Bet v 1-homologous food allergens were described for soy and peanut. In this study we assessed allergic reactions to another legume, to mungbean seedlings, and identified its Bet v 1-homologous allergen Vig r 1. Ten patients were selected who had a history of allergic reactions to mungbean seedlings and a respiratory allergy to birch pollen. The Bet v 1 homologue in mungbean seedlings, Vig r 1, was cloned by a PCR strategy, expressed in Escherichia coli, and purified by preparative SDS-PAGE. In all sera, specific IgE against birch pollen, Bet v 1, Bet v 2, Vig r 1, and the Bet v 1 homologues in soy (Gly m 4) and cherry (Pru av 1) was determined by CAP-FEIA. Cross-reactivity of specific IgE with Vig r 1, Bet v 1, Gly m 4, and Pru av 1 was assessed by immunoblot inhibition. Expression of Vig r 1 during development of mungbean seedlings and under wounding stress was analysed by immunoblotting. The Vig r 1 double band was analysed by matrix-assisted laser desorption/ionization time-of-flight and liquid chromatography/tandem mass spectrometry (LC/MS/MS). All patients were sensitized to birch pollen and Bet v 1, 20% to Bet v 2, and 90% to Gly m 4. Seventy percent of the patients showed IgE binding to a double band at 15 kDa in mungbean extract that was inhibited after pre-incubation of sera with rBet v 1. PCR cloning revealed that the mungbean homologue of Bet v 1 had a molecular weight of 16.2 kDa, a calculated pI of 4.6% and 42.8% amino acid sequence identity with Bet v 1. MS analysis confirmed similarity of the double band with the deduced Vig r 1 sequence, but also indicated the existence of other Vig r 1 isoforms. ImmunoCAP analysis detected IgE against Vig r 1 in 80% of the sera. IgE binding to Vig r 1 was inhibited with Gly m 4 in six of six and with rPru av 1 in four of six patients. Vig r 1 expression occurred during development of seedlings and was increased by wounding stress. Food allergy to mungbean

  2. Feeding and the rhodopsin family G-Protein Coupled Receptors (GPCRs in nematodes and arthropods

    Directory of Open Access Journals (Sweden)

    Joao Carlos dos Reis Cardoso

    2012-12-01

    Full Text Available In vertebrates, receptors of the rhodopsin G-protein coupled superfamily (GPCRs play an important role in the regulation of feeding and energy homeostasis and are activated by peptide hormones produced in the brain-gut axis. These peptides regulate appetite and energy expenditure by promoting or inhibiting food intake. Sequence and function homologues of human GPCRs involved in feeding exist in the nematode roundworm, Caenorhabditis elegans (C. elegans and the arthropod fruit fly, Drosophila melanogaster (D. melanogaster, suggesting that the mechanisms that regulate food intake emerged early and have been conserved during metazoan radiation. Nematodes and arthropods are the most diverse and successful animal phyla on Earth. They can survive in a vast diversity of environments and have acquired distinct life styles and feeding strategies. The aim of the present review is to investigate if this diversity has affected the evolution of invertebrate GPCRs. Homologues of the C. elegans and D. melanogaster rhodopsin receptors were characterized in the genome of other nematodes and arthropods and receptor evolution compared. With the exception of bombesin receptors (BBR that are absent from nematodes, a similar gene complement was found. In arthropods, rhodopsin GPCR evolution is characterized by species-specific gene duplications and deletions and in nematodes by gene expansions in species with a free-living stage and gene deletions in representatives of obligate parasitic taxa. Based upon variation in GPCR gene number and potentially divergent functions within phyla we hypothesize that life style and feeding diversity practiced by nematodes and arthropods was one factor that contributed to rhodopsin GPCR gene evolution. Understanding how the regulation of food intake has evolved in invertebrates will contribute to the development of novel drugs to control nematodes and arthropods and the pests and diseases that use them as vectors.

  3. Studies on the Physicochemical Properties, Structure and Antitumor Activity of an Oligosaccharide Homologue SnS-2 from the Root of Scrophularia ningpoensis Hemsl

    Institute of Scientific and Technical Information of China (English)

    DENG,Jun-E(邓军娥); ZHANG,Jian(张健); CHEN,Xiao-Ming(陈晓明); KE,Wei(柯炜); TIAN,Geng-Yuan(田庚元)

    2004-01-01

    An oligosaccharide homologue named SnS-2 was isolated from the root of Scrophularia ningpoensis Hemsl.SnS-2 was purified by means of gel-permeation chromatography and ion-exchange chromatography.Its physicochemical properties,including carbohydrate content and molecular weight were determined.The structure of SnS-2was elucidated by chemical methods along with 1H and 13C NMR spectroscopy,including two-dimensional DQCOSY and H-detected 1H,13C HMQC experiments.These results show that SnS-2 possesses a backbone consisting of terminal α-Galp-(1→,α-Galp-(1→6),α-Glcp-(1→6) and nonreducing end fβ-Fruf-(2→.The bioactive assay showed that it could inhibit the growth of Lewis pulmonary carcinoma implanted in mice.

  4. The small GTPase Rab5 homologue Ypt5 regulates cell morphology, sexual development, ion-stress response and vacuolar formation in fission yeast

    Energy Technology Data Exchange (ETDEWEB)

    Tsukamoto, Yuta; Katayama, Chisako [Graduate School of Science, Kobe University, 1-1 Rokkodai-cho Nada, Kobe 657-8501 (Japan); Shinohara, Miki; Shinohara, Akira [Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Maekawa, Shohei [Graduate School of Science, Kobe University, 1-1 Rokkodai-cho Nada, Kobe 657-8501 (Japan); Miyamoto, Masaaki, E-mail: miya@kobe-u.ac.jp [Graduate School of Science, Kobe University, 1-1 Rokkodai-cho Nada, Kobe 657-8501 (Japan); Center for Supports to Research and Education Activities, Kobe University, 1-1 Rokkodai-cho Nada, Kobe 657-8501 (Japan)

    2013-11-29

    Highlights: •Multiple functions of Rab5 GTPase in fission yeast were found. •Roles of Rab5 in fission yeast were discussed. •Relation between Rab5 and actin cytoskeleton were discussed. -- Abstract: Inner-membrane transport is critical to cell function. Rab family GTPases play an important role in vesicle transport. In mammalian cells, Rab5 is reported to be involved in the regulation of endosome formation, phagocytosis and chromosome alignment. Here, we examined the role of the fission yeast Rab5 homologue Ypt5 using a point mutant allele. Mutant cells displayed abnormal cell morphology, mating, sporulation, endocytosis, vacuole fusion and responses to ion stress. Our data strongly suggest that fission yeast Rab5 is involved in the regulation of various types of cellular functions.

  5. Tsp66E, the Drosophila KAI1 homologue, and Tsp74F function to regulate ovarian follicle cell and wing development by stabilizing integrin localization.

    Science.gov (United States)

    Han, Seung Yeop; Lee, Minjung; Hong, Yoon Ki; Hwang, Soojin; Choi, Gahee; Suh, Yoon Seok; Park, Seung Hwan; Lee, Soojin; Lee, Sang-Hee; Chung, Jongkyeong; Baek, Sung Hee; Cho, Kyoung Sang

    2012-11-16

    The metastasis suppressor KAI1/CD82 has been implicated in various cellular processes; however, its function in development is not fully understood. Here, we generated and characterized mutants of Tsp66E and Tsp74F, which are Drosophila homologues of KAI1/CD82 and Tspan11, respectively. These mutants exhibited egg elongation defects along with disturbed integrin localization and actin polarity. Moreover, the defects were enhanced by mutation of inflated, an αPS2 integrin gene. Mutant ovaries had elevated αPS2 integrin levels and reduced endocytic trafficking. These results suggest that Drosophila KAI1/CD82 affects the polarized localization and the level of integrin, which may contribute to epithelial cell polarity.

  6. Rye inhibitors of animal alpha-amylases show different specificities, aggregative properties and IgE-binding capacities than their homologues from wheat and barley.

    Science.gov (United States)

    García-Casado, G; Sánchez-Monge, R; López-Otín, C; Salcedo, G

    1994-09-01

    Three new members of the alpha-amylase/trypsin-inhibitor family of cereal endosperm have been isolated from rye. N-terminal amino acid sequence comparison revealed that two of the purified proteins were the rye homologues of the barley monomeric inhibitor (BMAI-1) previously described, while the other rye protein corresponded to one of the subunits of the barley and wheat heterotetrameric inhibitors. However, the inhibitory specificities (active against human salivary alpha-amylase), aggregative behaviours (mainly as dimeric forms) and IgE-binding capacities (not recognized by sera from allergic patients) of the rye inhibitors were clearly different from those of their wheat and barley counterparts. These results indicate that homologous inhibitors may have distinctive properties in different cereal species.

  7. Six3, a medaka homologue of the Drosophila homeobox gene sine oculis is expressed in the anterior embryonic shield and the developing eye.

    Science.gov (United States)

    Loosli, F; Köster, R W; Carl, M; Krone, A; Wittbrodt, J

    1998-06-01

    homologue Six3 (Oliver, G., Mailhos, A., Wehr, R., Copeland, N.G., Jenkins, N.A., Gruss, P., 1995. Six3, a murine homologue of the sine oculis gene, demarcates the most anterior border of the developing neural plate and is expressed during eye development. Development 121, 4045-4055). sine oculis (so) is essential for the development of the larval and adult visual system (Cheyette, B.N.R., Green, P.J., Martin, K., Garren, H., Hartenstein, V., Zipursky, S.L., 1994. The Drosophila sine oculis locus encodes a homeodomain-containing protein required for the development of the entire visual system. Neuron l2, 977-996). Six3 is expressed in the anterior neural plate and optic vesicles, lens, olfactory placodes and ventral forebrain (Oliver, G., Mailhos, A., Wehr, R., Copeland, N.G., Jenkins, N.A., Gruss, P., 1995. Six3, a murine homologue of the sine oculis gene, demarcates the most anterior border of the developing neural plate and is expressed during eye development. Development 121, 4045-4055). Overexpression of mouse Six3 gene in medaka fish embryos (Orvzias latipes) results in the formation of an ectopic lens, indicating that Six3 activity can trigger the genetic pathway leading to lens formation (Oliver, G., Loosli, F., Koster, R., Wittbrodt, J., Gruss, P., 1996. Ectopic lens induction in fish in response to the murine homeobox gene Six3. Mech. Dev. 60, 233-239). We isolated the medaka Six3 homologue and analyzed its expression pattern in the medaka embryo. It is expressed initially in the anterior embryonic shield and later in the developing eye and prosencephalon. The early localized expression of Six3 suggests a role in the regionalization of the rostral head.

  8. Constitutive Expression of Sense & Antisense PtAP3, an AP3 Homologue Gene of Populus tomentosa, Affects Growth and Flowering Time in Transgenic Tobacco

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    To analyze the function of PtAP3, an APETALA3 (AP3) homologue gene isolated from Populus tomentosa Carr., the full length sequence (1 797 bp) and a fragment (870 bp) of PtAP3 were fused to a CaMV 35S promoter of pBI121 to generate the sense and antisense constructs of PtAP3. These constructs were transformed into tobacco by Agrobacterium infection of leaf disks and selection on kanamycin medium. Some sense and antisense transgenic tobacco plants were obtained by PCR and Southern blot analysis. Great phenotypic differences in transgenic tobacco plants were observed. Almost all of sense PtAP3 to transgenic tobaccos showed a higher growth rate than those of antisense transformants and a few developed pregnancy earlier than wild type seedlings and antisense transformants under the same conditions.

  9. Multidrug efflux pumps: the structures of prokaryotic ATP-binding cassette transporter efflux pumps and implications for our understanding of eukaryotic P-glycoproteins and homologues.

    Science.gov (United States)

    Kerr, Ian D; Jones, Peter M; George, Anthony M

    2010-02-01

    One of the Holy Grails of ATP-binding cassette transporter research is a structural understanding of drug binding and transport in a eukaryotic multidrug resistance pump. These transporters are front-line mediators of drug resistance in cancers and represent an important therapeutic target in future chemotherapy. Although there has been intensive biochemical research into the human multidrug pumps, their 3D structure at atomic resolution remains unknown. The recent determination of the structure of a mouse P-glycoprotein at subatomic resolution is complemented by structures for a number of prokaryotic homologues. These structures have provided advances into our knowledge of the ATP-binding cassette exporter structure and mechanism, and have provided the template data for a number of homology modelling studies designed to reconcile biochemical data on these clinically important proteins.

  10. GLP-1 Receptor Agonists

    Science.gov (United States)

    ... in Balance › GLP-1 Receptor Agonists Fact Sheet GLP-1 Receptor Agonists May, 2012 Download PDFs English Espanol Editors Silvio ... are too high or too low. What are GLP-1 receptor agonist medicines? GLP-1 receptor agonist medicines, also called ...

  11. Viable Ednra (Y129F) mice feature human mandibulofacial dysostosis with alopecia (MFDA) syndrome due to the homologue mutation.

    Science.gov (United States)

    Sabrautzki, Sibylle; Sandholzer, Michael A; Lorenz-Depiereux, Bettina; Brommage, Robert; Przemeck, Gerhard; Vargas Panesso, Ingrid L; Vernaleken, Alexandra; Garrett, Lillian; Baron, Katharina; Yildirim, Ali O; Rozman, Jan; Rathkolb, Birgit; Gau, Christine; Hans, Wolfgang; Hoelter, Sabine M; Marschall, Susan; Stoeger, Claudia; Becker, Lore; Fuchs, Helmut; Gailus-Durner, Valerie; Klingenspor, Martin; Klopstock, Thomas; Lengger, Christoph; Stefanie, Leuchtenberger; Wolf, Eckhard; Strom, Tim M; Wurst, Wolfgang; de Angelis, Martin Hrabě

    2016-12-01

    Animal models resembling human mutations are valuable tools to research the features of complex human craniofacial syndromes. This is the first report on a viable dominant mouse model carrying a non-synonymous sequence variation within the endothelin receptor type A gene (Ednra c.386A>T, p.Tyr129Phe) derived by an ENU mutagenesis program. The identical amino acid substitution was reported recently as disease causing in three individuals with the mandibulofacial dysostosis with alopecia (MFDA, OMIM 616367) syndrome. We performed standardized phenotyping of wild-type, heterozygous, and homozygous Ednra (Y129F) mice within the German Mouse Clinic. Mutant mice mimic the craniofacial phenotypes of jaw dysplasia, micrognathia, dysplastic temporomandibular joints, auricular dysmorphism, and missing of the squamosal zygomatic process as described for MFDA-affected individuals. As observed in MFDA-affected individuals, mutant Ednra (Y129F) mice exhibit hearing impairment in line with strong abnormalities of the ossicles and further, reduction of some lung volumetric parameters. In general, heterozygous and homozygous mice demonstrated inter-individual diversity of expression of the craniofacial phenotypes as observed in MFDA patients but without showing any cleft palates, eyelid defects, or alopecia. Mutant Ednra (Y129F) mice represent a valuable viable model for complex human syndromes of the first and second pharyngeal arches and for further studies and analysis of impaired endothelin 1 (EDN1)-endothelin receptor type A (EDNRA) signaling. Above all, Ednra (Y129F) mice model the recently published human MFDA syndrome and may be helpful for further disease understanding and development of therapeutic interventions.

  12. The Drosophila GIPC homologue can modulate myosin based processes and planar cell polarity but is not essential for development.

    Directory of Open Access Journals (Sweden)

    Alexandre Djiane

    Full Text Available Epithelia often show, in addition to the ubiquitous apico-basal (A/B axis, a polarization within the plane of the epithelium, perpendicular to the A/B axis. Such planar cell polarity (PCP is for example evident in the regular arrangement of the stereocilia in the cochlea of the mammalian inner ear or in (almost all Drosophila adult external structures. GIPCs (GAIP interacting protein, C terminus were first identified in mammals and bind to the Galphai GTPase activating protein RGS-GAIP. They have been proposed to act in a G-protein coupled complex controlling vesicular trafficking. Although GIPCs have been found to bind to numerous proteins including Frizzled receptors, which participate in PCP establishment, there is little in vivo evidence for the functional role(s of GIPCs. We show here that overexpressed Drosophila dGIPC alters PCP generation in the wing. We were however unable to find any binding between dGIPC and the Drosophila receptors Fz1 and Fz2. The effect of overexpressed dGIPC is likely due to an effect on the actin cytoskeleton via myosins, since it is almost entirely suppressed by removing a genomic copy of the Myosin VI/jaguar gene. Surprisingly, although dGIPC can interfere with PCP generation and myosin based processes, the complete loss-of-function of dGIPC gives viable adults with no PCP or other detectable defects arguing for a non-essential role of dGIPC in viability and normal Drosophila development.

  13. Mapping of a macular drusen susceptibility locus in rhesus macaques to the homologue of human chromosome 6q14-15.

    Science.gov (United States)

    Singh, Krishna K; Ristau, Steven; Dawson, William W; Krawczak, Michael; Schmidtke, Jörg

    2005-10-01

    Rhesus macaques (Macaca mulatta) are a natural model for retinal drusen formation. The present study aimed at clarifying whether chromosomal regions homologous to candidate genes for drusen formation and progression in humans are also associated with a drusen phenotype in rhesus macaques. Some 42 genetic markers from seven chromosomal regions implicated in macular degeneration syndromes in humans were tested for whether they identified homologous, polymorphic sequences in rhesus DNA. This was found to be the case for seven markers, all of which were subsequently screened for the presence of potentially disease-predisposing alleles in 52 randomly chosen adult animals from the Cayo Santiago population of rhesus macaques (Caribbean Primate Research Center, PR, USA). The high drusen prevalence expected in the Cayo Santiago colony was confirmed in our sample in that 38 animals were found to have drusen (73%). Logistic regression analysis revealed that some alleles of the rhesus homologue of anonymous human marker D6S1036 were consistently over-represented among affected animals. Of two candidate genes located in the respective region, allelic variation in one (IMPG1) showed strong association with drusen formation. We conclude that one or more genes located at the rhesus homologue of human 6q14-15 are likely to play a role in retinal drusen formation, a finding that represents a first step towards the identification of genetic factors implicated in macular drusen formation in rhesus macaques. This is an important tool for the separation of genetic and environmental factors which must occur before satisfactory management methods can be developed.

  14. New Orthogonal Transcriptional Switches Derived from Tet Repressor Homologues for Saccharomyces cerevisiae Regulated by 2,4-Diacetylphloroglucinol and Other Ligands.

    Science.gov (United States)

    Ikushima, Shigehito; Boeke, Jef D

    2017-03-17

    Here we describe the development of tightly regulated expression switches in yeast, by engineering distant homologues of Escherichia coli TetR, including the transcriptional regulator PhlF from Pseudomonas and others. Previous studies demonstrated that the PhlF protein bound its operator sequence (phlO) in the absence of 2,4-diacetylphloroglucinol (DAPG) but dissociated from phlO in the presence of DAPG. Thus, we developed a DAPG-Off system in which expression of a gene preceded by the phlO-embedded promoter was activated by a fusion of PhlF to a multimerized viral activator protein (VP16) domain in a DAPG-free environment but repressed when DAPG was added to growth medium. In addition, we constructed a DAPG-On system with the opposite behavior of the DAPG-Off system; i.e., DAPG triggers the expression of a reporter gene. Exposure of DAPG to yeast cells did not cause any serious deleterious effect on yeast physiology in terms of growth. Efforts to engineer additional Tet repressor homologues were partially successful and a known mammalian switch, the p-cumate switch based on CymR from Pseudomonas, was found to function in yeast. Orthogonality between the TetR (doxycycline), CamR (d-camphor), PhlF (DAPG), and CymR (p-cumate)-based Off switches was demonstrated by evaluating all 4 ligands against suitably engineered yeast strains. This study expands the toolbox of "On" and "Off" switches for yeast biotechnology.

  15. The Ca{sup 2+} channel TRPML3 specifically interacts with the mammalian ATG8 homologue GATE16 to regulate autophagy

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Suzy; Kim, Hyun Jin, E-mail: kimhyunjin@skku.edu

    2014-01-03

    Highlights: •Split-ubiquitin MY2H screen identified GATE16 as an interacting protein of TRPML3. •TRPML3 specifically binds to a mammalian ATG8 homologue GATE16, not to LC3B. •The interaction of TRPML3 with GATE16 facilitates autophagosome formation. •GATE16 is expressed in both autophagosome and extra-autophagosomal compartments. -- Abstract: TRPML3 is a Ca{sup 2+} permeable cation channel expressed in multiple intracellular compartments. Although TRPML3 is implicated in autophagy, how TRPML3 can regulate autophagy is not understood. To search interacting proteins with TRPML3 in autophagy, we performed split-ubiquitin membrane yeast two-hybrid (MY2H) screening with TRPML3-loop as a bait and identified GATE16, a mammalian ATG8 homologue. GST pull-down assay revealed that TRPML3 and TRPML3-loop specifically bind to GATE16, not to LC3B. Co-immunoprecipitation (co-IP) experiments showed that TRPML3 and TRPML3-loop pull down only the lipidated form of GATE16, indicating that the interaction occurs exclusively at the organellar membrane. The interaction of TRPML3 with GATE16 and GATE16-positive vesicle formation were increased in starvation induced autophagy, suggesting that the interaction facilitates the function of GATE16 in autophagosome formation. However, GATE16 was not required for TRPML3 trafficking to autophagosomes. Experiments using dominant-negative (DN) TRPML3(D458K) showed that GATE16 is localized not only in autophagosomes but also in extra-autophagosomal compartments, by contrast with LC3B. Since GATE16 acts at a later stage of the autophagosome biogenesis, our results suggest that TRPML3 plays a role in autophagosome maturation through the interaction with GATE16, by providing Ca{sup 2+} in the fusion process.

  16. In situ hybridization analysis of the expression of futsch, tau, and MESK2 homologues in the brain of the European honeybee (Apis mellifera L..

    Directory of Open Access Journals (Sweden)

    Kumi Kaneko

    Full Text Available BACKGROUND: The importance of visual sense in Hymenopteran social behavior is suggested by the existence of a Hymenopteran insect-specific neural circuit related to visual processing and the fact that worker honeybee brain changes morphologically according to its foraging experience. To analyze molecular and neural bases that underlie the visual abilities of the honeybees, we used a cDNA microarray to search for gene(s expressed in a neural cell-type preferential manner in a visual center of the honeybee brain, the optic lobes (OLs. METHODOLOGY/PRINCIPAL FINDINGS: Expression analysis of candidate genes using in situ hybridization revealed two genes expressed in a neural cell-type preferential manner in the OLs. One is a homologue of Drosophila futsch, which encodes a microtubule-associated protein and is preferentially expressed in the monopolar cells in the lamina of the OLs. The gene for another microtubule-associated protein, tau, which functionally overlaps with futsch, was also preferentially expressed in the monopolar cells, strongly suggesting the functional importance of these two microtubule-associated proteins in monopolar cells. The other gene encoded a homologue of Misexpression Suppressor of Dominant-negative Kinase Suppressor of Ras 2 (MESK2, which might activate Ras/MAPK-signaling in Drosophila. MESK2 was expressed preferentially in a subclass of neurons located in the ventral region between the lamina and medulla neuropil in the OLs, suggesting that this subclass is a novel OL neuron type characterized by MESK2-expression. These three genes exhibited similar expression patterns in the worker, drone, and queen brains, suggesting that they function similarly irrespective of the honeybee sex or caste. CONCLUSIONS: Here we identified genes that are expressed in a monopolar cell (Amfutsch and Amtau or ventral medulla-preferential manner (AmMESK2 in insect OLs. These genes may aid in visualizing neurites of monopolar cells and ventral

  17. Deficiency in frataxin homologue YFH1 in the yeast Pichia guilliermondii leads to missregulation of iron acquisition and riboflavin biosynthesis and affects sulfate assimilation.

    Science.gov (United States)

    Pynyaha, Yuriy V; Boretsky, Yuriy R; Fedorovych, Daria V; Fayura, Lubov R; Levkiv, Andriy I; Ubiyvovk, Vira M; Protchenko, Olha V; Philpott, Caroline C; Sibirny, Andriy A

    2009-12-01

    Pichia guilliermondii is a representative of yeast species that overproduce riboflavin (vitamin B2) in response to iron deprivation. P. guilliermondii YFH1 gene coding for frataxin homologue, eukaryotic mitochondrial protein involved in iron trafficking and storage, was identified and deleted. Constructed P. guilliermondii Δyfh1 mutant grew very poorly in a sucrose-containing synthetic medium supplemented with sulfate or sulfite as a sole sulfur source. Addition of sodium sulfide, glutathione, cysteine, methionine, N-acetyl-L-cysteine partially restored growth rate of the mutant suggesting that it is impaired in sulfate assimilation. Cellular iron content in Δyfh1 mutant was ~3-3.5 times higher as compared to the parental strain. It produced 50-70 times more riboflavin in iron sufficient synthetic media relative to the parental wildtype strain. Biomass yield of the mutant in the synthetic glutathione containing medium supplemented with glycerol as a sole carbon source was 1.4- and 2.6-fold increased as compared to sucrose and succinate containing media, respectively. Oxygen uptake of the Δyfh1 mutant on sucrose, glycerol or succinate, when compared to the parental strain, was decreased 5.5-, 1.7- and 1.5-fold, respectively. Substitution of sucrose or glycerol in the synthetic iron sufficient medium with succinate completely abolished riboflavin overproduction by the mutants. Deletion of the YFH1 gene caused hypersensitivity to hydrogen peroxide and exogenously added riboflavin and led to alterations in superoxide dismutase activities. Thus, deletion of the gene coding for yeast frataxin homologue has pleiotropic effect on metabolism in P. guilliermondii.

  18. Ischemia and reperfusion induce differential expression of calpastatin and its homologue high molecular weight calmodulin-binding protein in murine cardiomyocytes.

    Directory of Open Access Journals (Sweden)

    Sreejit Parameswaran

    Full Text Available In the heart, calpastatin (Calp and its homologue high molecular weight calmodulin-binding protein (HMWCaMBP regulate calpains (Calpn by inhibition. A rise in intracellular myocardial Ca2+ during cardiac ischemia activates Calpn thereby causing damage to myocardial proteins, which leads to myocyte death and consequently to loss of myocardial structure and function. The present study aims to elucidate expression of Calp and HMWCaMBP with respect to Calpn during induced ischemia and reperfusion in primary murine cardiomyocyte cultures. Ischemia and subsequently reperfusion was induced in ∼ 80% confluent cultures of neonatal murine cardiomyocytes (NMCC. Flow cytometric analysis (FACS has been used for analyzing protein expression concurrently with viability. Confocal fluorescent microscopy was used to observe protein localization. We observed that ischemia induces increased expression of Calp, HMWCaMBP and Calpn. Calpn expressing NMCC on co-expressing Calp survived ischemic induction compared to NMCC co-expressing HMWCaMBP. Similarly, living cells expressed Calp in contrast to dead cells which expressed HMWCaMBP following reperfusion. A significant difference in the expression of Calp and its homologue HMWCaMBP was observed in localization studies during ischemia. The current study adds to the existing knowledge that HMWCaMBP could be a putative isoform of Calp. NMCC on co-expressing Calp and Calpn-1 survived ischemic and reperfusion inductions compared to NMCC co-expressing HMWCaMBP and Calpn-1. A significant difference in expression of Calp and HMWCaMBP was observed in localization studies during ischemia.

  19. A gonococcal homologue of meningococcal γ-glutamyl transpeptidase gene is a new type of bacterial pseudogene that is transcriptionally active but phenotypically silent

    Directory of Open Access Journals (Sweden)

    Watanabe Haruo

    2005-10-01

    Full Text Available Abstract Background It has been speculated that the γ-glutamyl transpeptidase (ggt gene is present only in Neisseria meningitidis and not among related species such as Neisseria gonorrhoeae and Neisseria lactamica, because N. meningitidis is the only bacterium with GGT activity. However, nucleotide sequences highly homologous to the meningococcal ggt gene were found in the genomes of N. gonorrhoeae isolates. Results The gonococcal homologue (ggt gonococcal homologue; ggh was analyzed. The nucleotide sequence of the ggh gene was approximately 95 % identical to that of the meningococcal ggt gene. An open reading frame in the ggh gene was disrupted by an ochre mutation and frameshift mutations induced by a 7-base deletion, but the amino acid sequences deduced from the artificially corrected ggh nucleotide sequences were approximately 97 % identical to that of the meningococcal ggt gene. The analyses of the sequences flanking the ggt and ggh genes revealed that both genes were localized in a common DNA region containing the fbp-ggt (or ggh-glyA-opcA-dedA-abcZ gene cluster. The expression of the ggh RNA could be detected by dot blot, RT-PCR and primer extension analyses. Moreover, the truncated form of ggh-translational product was also found in some of the gonococcal isolates. Conclusion This study has shown that the gonococcal ggh gene is a pseudogene of the meningococcal ggt gene, which can also be designated as Ψggt. The gonococcal ggh (Ψggt gene is the first identified bacterial pseudogene that is transcriptionally active but phenotypically silent.

  20. Molecular cloning and identification of mouse epididymis-specific gene mHong1, the homologue of rat HongrES1

    Institute of Scientific and Technical Information of China (English)

    Shuang-Gang Hu; Han Du; Guang-Xin Yao; Yong-Lian Zhang

    2012-01-01

    Previous studies have shown that rat epididymis-specific gene HongrES1 plays important roles in sperm capacitation and fertility.In this study,we cloned the mouse homologue gene by sequence alignment and RT-PCR methods and designated it as mHong1.The mHong1 gene is located on chromosome 12p14,spanning five exons.The cDNA sequence consists of 1257 nucleotides and encodes a 419 amino-acid protein with a predicted N-terminal signal peptide of 20 amino acids.The mHong1 mRNA shows similarity with HongrES1 in the expression patterns:(i) specific expression in epididymal tissue,especially in the cauda region; and (ii) androgen-dependence but testicular fluid factor independence.Its protein product shows 71% similarity with HongrES 1 and contains a classical serpin domain as does HongrES1.A polyclonal antibody against mHong1 with high specificity and sensitivity was raised.Like HongrES1,the mHong1 protein shows a checker-board expression pattern in the epididymal epithelium and is secreted into the epididymal lumen.The mHong1 protein shows higher glycosylation than HongrES1.Although both of them are deposited onto the sperm head surface,mHong 1 is localized to the equatorial segment,which is different from that of HongrES 1.The mHong1 protein can be removed from the sperm membrane by high ionic strength and therefore can be classed as an extrinsic membrane protein.Collectively,we conclude that mHong1 is the homologue of HongrES1 and the present work paves the way for establishing animal models to elucidate the precise functions of HongrES1 and mHong1.

  1. Characterization of the Distal-less gene homologue, NlDll, in the brown planthopper, Nilaparvata lugens (Stål).

    Science.gov (United States)

    Lin, Xinda; Yao, Yun; Jin, Minna; Li, Qilin

    2014-02-10

    The brown planthopper, Nilaparvata lugens (Stål), is a globally devastating insect pest of rice, particularly in eastern Asia. Distal-less or Dll is a highly conserved and well studied transcription factor required for limb formation in invertebrates and vertebrates. We have identified a homologue of this gene, NlDll, and demonstrated that it is expressed in all life stages of N. lugens, particularly in adult brachypterous females. When we compared between specific adult tissues it was expressed most strongly in wings. Using RNAi techniques we demonstrated that downregulation of NlDll in the 3rd instar larvae led to the disrupted development of the leg, while downregulation of NlDll in the 5th instar larvae led to abnormal wing formation. Ectopic over-expression of NlDll in Drosophila melanogaster using the GAL4-UAS system led to fatal or visible phenotypic changes such as the loss of normal wing structure and disrupted haltere structure. Our work suggests that NlDll is a conserved homologue of Distal-less and is required for both leg development and wing structure. Since researches have shown that Dll is required for wing morphogenesis, understanding the role of NlDll during the wing development will further provide a basis for revealing the molecular mechanism of the wing dimorphism in brown planthopper. In the future, NlDll could be used as a target gene for brown planthopper pest management in the field. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  2. Interleukin 8 Receptor Deficiency Confers Susceptibility to Acute Experimental Pyelonephritis and May Have a Human Counterpart

    Science.gov (United States)

    Frendéus, Björn; Godaly, Gabriela; Hang, Long; Karpman, Diana; Lundstedt, Ann-Charlotte; Svanborg, Catharina

    2000-01-01

    Neutrophils migrate to infected mucosal sites that they protect against invading pathogens. Their interaction with the epithelial barrier is controlled by CXC chemokines and by their receptors. This study examined the change in susceptibility to urinary tract infection (UTI) after deletion of the murine interleukin 8 receptor homologue (mIL-8Rh). Experimental UTIs in control mice stimulated an epithelial chemokine response and increased chemokine receptor expression. Neutrophils migrated through the tissues to the epithelial barrier that they crossed into the lumen, and the mice developed pyuria. In mIL-8Rh knockout (KO) mice, the chemokine response was intact, but the epithelial cells failed to express IL-8R, and neutrophils accumulated in the tissues. The KO mice were unable to clear bacteria from kidneys and bladders and developed bacteremia and symptoms of systemic disease, but control mice were fully resistant to infection. The experimental UTI model demonstrated that IL-8R–dependent mechanisms control the urinary tract defense, and that neutrophils are essential host effector cells. Patients prone to acute pyelonephritis also showed low CXC chemokine receptor 1 expression compared with age-matched controls, suggesting that chemokine receptor expression may also influence the susceptibility to UTIs in humans. The results provide a first molecular clue to disease susceptibility of patients prone to acute pyelonephritis. PMID:10993918

  3. Negative Regulation of Receptor Tyrosine Kinase (RTK Signaling: A Developing Field

    Directory of Open Access Journals (Sweden)

    Fernanda Ledda

    2007-01-01

    Full Text Available ophic factors control cellular physiology by activating specific receptor tyrosine kinases (RTKs. While the over activation of RTK signaling pathways is associated with cell growth and cancer, recent findings support the concept that impaired down-regulation or deactivation of RTKs may also be a mechanism involved in tumor formation. Under this perspective, the molecular determinants of RTK signaling inhibition may act as tumor-suppressor genes and have a potential role as tumor markers to monitor and predict disease progression. Here, we review the current understanding of the physiological mechanisms that attenuate RTK signaling and discuss evidence that implicates deregulation of these events in cancer.Abbreviations: BDP1: Brain-derived phosphatase 1; Cbl: Casitas B-lineage lymphoma; CIN-85: Cbl-interacting protein of 85 kDa; DER: Drosophila EGFR; EGFR: Epidermal growth factor receptor; ERK 1/2: Extracellular signal-regulated kinase 1/2; Grb2: Growth factor receptor-bound protein 2; HER2: Human epidermal growth factor receptor 2; LRIG: Leucine-rich repeats and immunoglobulin-like domain 1; MAPK: Mitogen-activated protein kinase; Mig 6: Mitogen-inducible gene 6; PTEN: Phosphatase and tensin homologue; RET: Rearranged in transformation; RTK: Receptor tyrosine kinase. SH2 domain: Src-homology 2 domain; SH3 domain: Src-homology 3 domain; Spry: Sprouty.

  4. Genome-wide screening reveals the emergence and divergence of RTK homologues in basal Metazoan Hydra magnipapillata

    Indian Academy of Sciences (India)

    P C Reddy; Salil S Bidaye; Surendra Ghaskadbi

    2011-06-01

    Receptor tyrosine kinases (RTKs) are key components of cell–cell signalling required for growth and development of multicellular organisms. It is therefore likely that the divergence of RTKs and associated components played a significant role in the evolution of multicellular organisms. We have carried out the present study in hydra, a diploblast, to investigate the divergence of RTKs after parazoa and before emergence of triploblast phyla. The domain-based screening using Hidden Markov Models (HMMs) for RTKs in Genomescan predicted gene models of the Hydra magnipapillata genome resulted in identification of 15 RTKs. These RTKs have been classified into eight families based on domain architecture and homology. Only 5 of these RTKs have been previously reported and a few of these have been partially characterized. A phylogeny-based analysis of these predicted RTKs revealed that seven subtype duplications occurred between `parazoan–eumetazoan split’ and `diploblast–triploblast split’ in animal phyla. These results suggest that most of the RTKs evolved before the radiata–bilateria divergence during animal evolution.

  5. SARM: a novel Toll-like receptor adaptor, is functionally conserved from arthropod to human.

    Science.gov (United States)

    Belinda, Loh Wei-Ching; Wei, Wang Xiao; Hanh, Bui Thi Hong; Lei, Luan Xiao; Bow, Ho; Ling, Ding Jeak

    2008-03-01

    Sterile-alpha and Armadillo motif containing protein (SARM) was recently identified as the fifth member of the Toll-like receptor (TLR) adaptor family. Whilst the Caenorhabditis elegans SARM homologue, TIR-1, is crucial for efficient immune responses against bacterial infections, human SARM was demonstrated to function as a specific inhibitor of TRIF-dependent TLR signaling. The opposing role of SARM in C. elegans and human is intriguing, prompting us to seek clarification on the enigmatic function of SARM in an ancient species which relies solely on innate immunity for survival. Here, we report the discovery of a primitive but functional SARM (CrSARM) in the immune defense of a "living fossil", the horseshoe crab, Carcinoscorpius rotundicauda. CrSARM shares numerous signature motifs and displays significant homology with vertebrate and invertebrate SARM homologues. CrSARM downregulates TRIF-dependent TLR signaling suggesting the conservation of SARM function from horseshoe crab to human. During infection by Pseudomonas aeruginosa, CrSARM is rapidly upregulated within 3h and strongly repressed at 6h, coinciding with the timing of bacterial clearance, thus demonstrating its dynamic role in innate immunity. Furthermore, yeast-two-hybrid screening revealed several potential interaction partners of CrSARM implying the role of SARM in downregulating TLR signaling events. Altogether, our study shows that, although C. elegans SARM upregulates immune signaling, its disparate role as a suppressor of TLR signaling, specifically via TRIF and not MyD88, is well-conserved from horseshoe crab to human.

  6. The impact of different intensities of green light on the bacteriochlorophyll homologue composition of the Chlorobiaceae Prosthecochloris aestuarii and Chlorobium phaeobacteroides.

    Science.gov (United States)

    Massé, Astrid; Airs, Ruth L; Keely, Brendan J; de Wit, Rutger

    2004-08-01

    Members of the Chlorobiaceae and Chloroflexaceae are unique among the phototrophic micro-organisms in having a remarkably rich chlorophyll pigment diversity. The physiological regulation of this diversity and its ecological implications are still enigmatic. The bacteriochlorophyll composition of the chlorobiaceae Prosthecochloris aestuarii strain CE 2404 and Chlorobium phaeobacteroides strain UdG 6030 was therefore studied by both HPLC with photodiode array (PDA) detection and liquid chromatography-mass spectrometry (LC-MS). These strains were grown in liquid cultures under green light (480-615 nm) at different light intensities (0.2-55.7 micromol photons m(-2) s(-1)), simulating the irradiance regime at different depths of the water column of deep lakes. The specific growth rates of Ptc. aestuarii under green light achieved a maximum of 0.06 h(-1) at light intensities exceeding 6 micromol photons m(-2) s(-1), lower than the maximum observed under white light (approx. 0.1 h(-1)). The maximal growth rates of Chl. phaeobacteroides under green light were slightly higher (0.07 h(-1)) than observed for Ptc. aestuarii and were achieved at 3.5 and 4.3 micromol photons m(-2) s(-1). LC-MS/MS analysis of pigment extracts revealed most (>90 %) BChl c homologues of Ptc. aestuarii to be esterified with farnesol. The homologues differed in mass by multiples of 14 Da, reflecting different alkyl subsituents at positions C-8 and C-12 on the tetrapyrrole macrocycle. The relative proportions of the individual homologues varied only slightly among different light intensities. The specific content of BChl c was maximal at 3-5 micromol photons m(-2) s(-1) [400+/-150 nmol BChl c (mg protein)(-1)]. In the case of Chl. phaeobacteroides, the specific content of BChl e was maximal at 4.3 micromol photons m(-2) s(-1) [115 nmol BChl e (mg protein)(-1)], and this species was characterized by high carotenoid (isorenieratene) contents. The major BChl e forms were esterified with a range of

  7. Acetylcholine receptor antibody

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003576.htm Acetylcholine receptor antibody To use the sharing features on this page, please enable JavaScript. Acetylcholine receptor antibody is a protein found in the blood ...

  8. Structure of a NifS homologue: X-ray structure analysis of CsdB, an Escherichia coli counterpart of mammalian selenocysteine lyase.

    Science.gov (United States)

    Fujii, T; Maeda, M; Mihara, H; Kurihara, T; Esaki, N; Hata, Y

    2000-02-15

    Escherichia coli CsdB, a NifS homologue with a high specificity for L-selenocysteine, is a pyridoxal 5'-phosphate (PLP)-dependent dimeric enzyme that belongs to aminotransferases class V in fold-type I of PLP enzymes and catalyzes the decomposition of L-selenocysteine into selenium and L-alanine. The crystal structure of the enzyme has been determined by the X-ray crystallographic method of multiple isomorphous replacement and refined to an R-factor of 18.7% at 2.8 A resolution. The subunit structure consists of three parts: a large domain of an alpha/beta-fold containing a seven-stranded beta-sheet flanked by seven helices, a small domain containing a four-stranded antiparallel beta-sheet flanked by three alpha-helices, and an N-terminal segment containing two alpha-helices. The overall fold of the subunit is similar to those of the enzymes belonging to the fold-type I family represented by aspartate aminotransferase. However, CsdB has several structural features that are not observed in other families of the enzymes. A remarkable feature is that an alpha-helix in the lobe extending from the small domain to the large domain in one subunit of the dimer interacts with a beta-hairpin loop protruding from the large domain of the other subunit. The extended lobe and the protruded beta-hairpin loop form one side of a limb of each active site in the enzyme. The most striking structural feature of CsdB lies in the location of a putative catalytic residue; the side chain of Cys364 on the extended lobe of one subunit is close enough to interact with the gamma-atom of a modeled substrate in the active site of the subunit. Moreover, His55 from the other subunit is positioned so that it interacts with the gamma- or beta-atom of the substrate and may be involved in the catalytic reaction. This is the first report on three-dimensional structures of NifS homologues.

  9. Bonding analysis using localized relativistic orbitals: water, the ultrarelativistic case and the heavy homologues H2X (X = Te, Po, eka-Po).

    Science.gov (United States)

    Dubillard, S; Rota, J-B; Saue, T; Faegri, K

    2006-04-21

    We report the implementation of Pipek-Mezey [J. Chem. Phys. 90, 4916 (1989)] localization of molecular orbitals in the framework of a four-component relativistic molecular electronic structure theory. We have used an exponential parametrization of orbital rotations which allows the use of unconstrained optimization techniques. We demonstrate the strong basis set dependence of the Pipek-Mezey localization criterion and how it can be eliminated. We have employed localization in conjunction with projection analysis to study the bonding in the water molecule and its heavy homologues. We demonstrate that in localized orbitals the repulsion between hydrogens in the water molecule is dominated by electrostatic rather than exchange interactions and that freezing the oxygen 2s orbital blocks polarization of this orbital rather than hybridization. We also point out that the bond angle of the water molecule cannot be rationalized from the potential energy alone due to the force term of the molecular virial theorem that comes into play at nonequilibrium geometries and which turns out to be crucial in order to correctly reproduce the minimum of the total energy surface. In order to rapidly assess the possible relativistic effects we have carried out the geometry optimizations of the water molecule at various reduced speed of light with and without spin-orbit interaction. At intermediate speeds, the bond angle is reduced to around 90 degrees , as is known experimentally for H(2)S and heavier homologues, although our model of ultrarelativistic water by construction does not allow any contribution from d orbitals to bonding. At low speeds of light the water molecule becomes linear which is in apparent agreement with the valence shell electron pair repulsion (VSEPR) model since the oxygen 2s12 and 2p12 orbitals both become chemically inert. However, we show that linearity is brought about by the relativistic stabilization of the (n + 1)s orbital, the same mechanism that leads to an

  10. Light and auxin responsive cytochrome P450s from Withania somnifera Dunal: cloning, expression and molecular modelling of two pairs of homologue genes with differential regulation.

    Science.gov (United States)

    Srivastava, Sudhakar; Sangwan, Rajender Singh; Tripathi, Sandhya; Mishra, Bhawana; Narnoliya, L K; Misra, L N; Sangwan, Neelam S

    2015-11-01

    Cytochrome P450s (CYPs) catalyse a wide variety of oxygenation/hydroxylation reactions that facilitate diverse metabolic functions in plants. Specific CYP families are essential for the biosynthesis of species-specialized metabolites. Therefore, we investigated the role of different CYPs related to secondary metabolism in Withania somnifera, a medicinally important plant of the Indian subcontinent. In this study, complete complementary DNAs (cDNAs) of four different CYP genes were isolated and christened as WSCYP93Id, WSCYP93Sm, WSCYP734B and WSCYP734R. These cDNAs encoded polypeptides comprising of 498, 496, 522 and 550 amino acid residues with their deduced molecular mass of 56.7, 56.9, 59.4 and 62.2 kDa, respectively. Phylogenetic study and molecular modelling analysis of the four cloned WSCYPs revealed their categorization into two CYP families (CYP83B1 and CYP734A1) belonging to CYP71 and CYP72 clans, respectively. BLASTp searches showed similarity of 75 and 56 %, respectively, between the two CYP members of CYP83B1 and CYP734A1 with major variances exhibited in their N-terminal regions. The two pairs of homologues exhibited differential expression profiles in the leaf tissues of selected chemotypes of W. somnifera as well as in response to treatments such as methyl jasmonate, wounding, light and auxin. Light and auxin regulated two pairs of WSCYP homologues in a developing seedling in an interesting differential manner. Their lesser resemblance and homology with other CYP sequences suggested these genes to be more specialized and distinct ones. The results on chemotype-specific expression patterns of the four genes strongly suggested their key/specialized involvement of the CYPs in the biosynthesis of chemotype-specific metabolites, though their further biochemical characterization would reveal the specificity in more detail. It is revealed that WSCYP93Id and WSCYP93Sm may be broadly involved in the oxygenation reactions in the plant and, thereby, control

  11. A receptor tyrosine kinase, UFO/Axl, and other genes isolated by a modified differential display PCR are overexpressed in metastatic prostatic carcinoma cell line DU145.

    Science.gov (United States)

    Jacob, A N; Kalapurakal, J; Davidson, W R; Kandpal, G; Dunson, N; Prashar, Y; Kandpal, R P

    1999-01-01

    We have used a modified differential display PCR protocol for isolating 3' restriction fragments of cDNAs specifically expressed or overexpressed in metastatic prostate carcinoma cell line DU145. Several cDNA fragments were identified that matched to milk fat globule protein, UFO/Axl, a receptor tyrosine kinase, human homologue of a Xenopus maternal transcript, laminin and laminin receptor, human carcinoma-associated antigen, and some expressed sequence tags. The transcript for milk fat globule protein, a marker protein shown to be overexpressed in breast tumors, was elevated in DU145 cells. The expression of UFO/Axl, a receptor tyrosine kinase, was considerably higher in DU145 cells as compared to normal prostate cells and prostatic carcinoma cell line PC-3. The overexpression of UFO oncogene in DU145 cells is discussed in the context of prostate cancer metastasis.

  12. Androgen receptor abnormalities

    NARCIS (Netherlands)

    A.O. Brinkmann (Albert); G.G.J.M. Kuiper (George); C. Ris-Stalpers (Carolyn); H.C.J. van Rooij (Henri); G. Romalo (G.); G. Trifiro (Gianluca); E. Mulder (Eppo); L. Pinsky (L.); H.U. Schweikert (H.); J. Trapman (Jan)

    1991-01-01

    markdownabstract__Abstract__ The human androgen receptor is a member of the superfamily of steroid hormone receptors. Proper functioning of this protein is a prerequisite for normal male sexual differentiation and development. The cloning of the human androgen receptor cDNA and the elucidation of t

  13. Mammalian Sweet Taste Receptors

    National Research Council Canada - National Science Library

    Nelson, Greg; Hoon, Mark A; Chandrashekar, Jayaram; Zhang, Yifeng; Ryba, Nicholas J.P; Zuker, Charles S

    2001-01-01

    ... and information coding, and have focused on the isolation and characterization of genes encoding sweet and bitter taste receptors. The identification of taste receptors generates powerful molecular tools to investigate not only the function of taste receptor cells, but also the logic of taste coding. For example, defining the size and diversity of the re...

  14. [Melatonin receptor agonist].

    Science.gov (United States)

    Uchiyama, Makoto

    2015-06-01

    Melatonin is a hormone secreted by the pineal gland and is involved in the regulation of human sleep-wake cycle and circadian rhythms. The melatonin MT1 and MT2 receptors located in the suprachiasmatic nucleus in the hypothalamus play a pivotal role in the sleep-wake regulation. Based on the fact that MT1 receptors are involved in human sleep onset process, melatonin receptor agonists have been developed to treat insomnia. In this article, we first reviewed functions of melatonin receptors with special reference to MT1 and MT2, and properties and clinical application of melatonin receptor agonists as hypnotics.

  15. CD8: Adhesion Molecule, Co-Receptor and Immuno-Modulator

    Institute of Scientific and Technical Information of China (English)

    David K Cole; George F Gao

    2004-01-01

    CD8 is a cell surface glycoprotein found in cytotoxic T lymphocytes, which are important components in cellular immunity, esp. In the immune response to cancer and chronic infections. There are two forms of CD8,either as an αα homodimer or αβ heterodimer. It acts as an "assistant" or co-receptor in the function of cytotoxic T cells where specific immunity is mediated by interaction of specific T cell receptor (αβTCR) and its ligand peptide major histocompatibility complex (pMHC). CD8 also binds to pMHC but away from the interface of pMHC and TCR contact, thereof no influence on the specificity of this interaction. If the TCR and CD8 bind to the same pMHC at the same time, CD8 is defined as a co-receptor, functioning through its signalling via its cytoplasmic tyrosine phosphorylation pathway; if CD8 binds to pMHC independently of the TCR, it is defined as an adhesion molecule. At present, the co-receptor function theory is dominated in the field.Recent study has also shown that murine CD8αα binds to TL antigen, an MHC homologue, therefore acts as an immuno-modulator. In this review, we discuss these current understandings of the three aspects of the CD8 functions and their structural basis.

  16. CD8: Adhesion Molecule, Co-Receptor and Immuno-Modulator

    Institute of Scientific and Technical Information of China (English)

    DavidKCole; GeorgeFGao

    2004-01-01

    CD8 is a cell surface glycoprotein found in cytotoxic T lymphocytes, which are important components in cellular immunity, esp. in the immune response to cancer and chronic infections. There are two forms of CD8, either as an αα homodimer or αβ heterodimer. It acts as an "assistant" or co-receptor in the function of cytotoxic T cells where specific immunity is mediated by interaction of specific T cell receptor (αβTCR) and its ligand peptide major histocompatibility complex (pMHC). CD8 also binds to pMHC but away from the interface of pMHC and TCR contact, thereof no influence on the specificity of this interaction. If the TCR and CD8 bind to the same pMHC at the same time, CD8 is defined as a co-receptor, functioning through its signalling via its cytoplasmic tyrosine phosphorylation pathway; if CD8 binds to pMHC independently of the TCR, it is defined as an adhesion molecule. At present, the co-receptor function theory is dominated in the field. Recent study has also shown that murine CD8αα binds to TL antigen, an MHC homologue, therefore acts as an immuno-modulator. In this review, we discuss these current understandings of the three aspects of the CD8 functions and their structural basis. Cellular & Molecular Immunology. 2004;1(2):81-88.

  17. An outer membrane receptor of Neisseria meningitidis involved in zinc acquisition with vaccine potential.

    Directory of Open Access Journals (Sweden)

    Michiel Stork

    Full Text Available Since the concentration of free iron in the human host is low, efficient iron-acquisition mechanisms constitute important virulence factors for pathogenic bacteria. In Gram-negative bacteria, TonB-dependent outer membrane receptors are implicated in iron acquisition. It is far less clear how other metals that are also scarce in the human host are transported across the bacterial outer membrane. With the aim of identifying novel vaccine candidates, we characterized in this study a hitherto unknown receptor in Neisseria meningitidis. We demonstrate that this receptor, designated ZnuD, is produced under zinc limitation and that it is involved in the uptake of zinc. Upon immunization of mice, it was capable of inducing bactericidal antibodies and we could detect ZnuD-specific antibodies in human convalescent patient sera. ZnuD is highly conserved among N. meningitidis isolates and homologues of the protein are found in many other Gram-negative pathogens, particularly in those residing in the respiratory tract. We conclude that ZnuD constitutes a promising candidate for the development of a vaccine against meningococcal disease for which no effective universal vaccine is available. Furthermore, the results suggest that receptor-mediated zinc uptake represents a novel virulence mechanism that is particularly important for bacterial survival in the respiratory tract.

  18. Homologues of the Arabidopsis thaliana SHI/STY/LRP1 genes control auxin biosynthesis and affect growth and development in the moss Physcomitrella patens.

    Science.gov (United States)

    Eklund, D Magnus; Thelander, Mattias; Landberg, Katarina; Ståldal, Veronika; Nilsson, Anders; Johansson, Monika; Valsecchi, Isabel; Pederson, Eric R A; Kowalczyk, Mariusz; Ljung, Karin; Ronne, Hans; Sundberg, Eva

    2010-04-01

    The plant hormone auxin plays fundamental roles in vascular plants. Although exogenous auxin also stimulates developmental transitions and growth in non-vascular plants, the effects of manipulating endogenous auxin levels have thus far not been reported. Here, we have altered the levels and sites of auxin production and accumulation in the moss Physcomitrella patens by changing the expression level of homologues of the Arabidopsis SHI/STY family proteins, which are positive regulators of auxin biosynthesis genes. Constitutive expression of PpSHI1 resulted in elevated auxin levels, increased and ectopic expression of the auxin response reporter GmGH3pro:GUS, and in an increased caulonema/chloronema ratio, an effect also induced by exogenous auxin application. In addition, we observed premature ageing and necrosis in cells ectopically expressing PpSHI1. Knockout of either of the two PpSHI genes resulted in reduced auxin levels and auxin biosynthesis rates in leafy shoots, reduced internode elongation, delayed ageing, a decreased caulonema/chloronema ratio and an increased number of axillary hairs, which constitute potential auxin biosynthesis sites. Some of the identified auxin functions appear to be analogous in vascular and non-vascular plants. Furthermore, the spatiotemporal expression of the PpSHI genes and GmGH3pro:GUS strongly overlap, suggesting that local auxin biosynthesis is important for the regulation of auxin peak formation in non-vascular plants.

  19. First report of a thioredoxin homologue in jellyfish: molecular cloning, expression and antioxidant activity of CcTrx1 from Cyanea capillata.

    Directory of Open Access Journals (Sweden)

    Zengliang Ruan

    Full Text Available Thioredoxins (Trx proteins are a family of small, highly-conserved and ubiquitous proteins that play significant roles in the resistance of oxidative damage. In this study, a homologue of Trx was identified from the cDNA library of tentacle of the jellyfish Cyanea capillata and named CcTrx1. The full-length cDNA of CcTrx1 was 479 bp with a 312 bp open reading frame encoding 104 amino acids. Bioinformatics analysis revealed that the putative CcTrx1 protein harbored the evolutionarily-conserved Trx active site 31CGPC34 and shared a high similarity with Trx1 proteins from other organisms analyzed, indicating that CcTrx1 is a new member of Trx1 sub-family. CcTrx1 mRNA was found to be constitutively expressed in tentacle, umbrella, oral arm and gonad, indicating a general role of CcTrx1 protein in various physiological processes. The recombinant CcTrx1 (rCcTrx1 protein was expressed in Escherichia coli BL21 (DE3, and then purified by affinity chromatography. The rCcTrx1 protein was demonstrated to possess the expected redox activity in enzymatic analysis and protection against oxidative damage of supercoiled DNA. These results indicate that CcTrx1 may function as an important antioxidant in C. capillata. To our knowledge, this is the first Trx protein characterized from jellyfish species.

  20. The shf gene of a Shigella flexneri homologue on the virulent plasmid pAA2 of enteroaggregative Escherichia coli 042 is required for firm biofilm formation.

    Science.gov (United States)

    Fujiyama, Rika; Nishi, Junichiro; Imuta, Naoko; Tokuda, Koichi; Manago, Kunihiro; Kawano, Yoshifumi

    2008-05-01

    Enteroaggregative Escherichia coli (EAEC) is an increasingly important cause of diarrhea in both developing and industrialized countries, and is characterized by strong biofilm formation on the intestinal mucosa. Sequencing of the virulent plasmid pAA2 of the prototype EAEC 042 revealed a cluster of three open reading frames (ORFs; shf, capU, and virK) ca. 93% identical to a similar cluster located in Shigella flexneri. The function of the first ORF Shf protein is not known, but the closest well-characterized homologue is the IcaB protein of Staphylococcus epidermidis, which plays a crucial role in exopolysaccharide modification in bacterial biofilm formation. To investigate the role of this cluster in the virulence of EAEC, we mutated three genes at this locus. All the mutants maintained the aggregative phenotype in the liquid phase. However, the insertional mutant of shf formed a less abundant biofilm in a microtiter plate assay than did the wild type, while the capU mutant and the virK mutant did not. The complementation of the shf mutant with this cluster restored the thick biofilm similar to that of the wild type. The shf transcriptional level decreased in the transcriptional regulator aggR mutant and was restored when the mutant was complemented with aggR. These results suggest that the shf gene is required for the firm biofilm formation of EAEC 042, and transcription of the shf gene is dependent on AggR.

  1. LC2, the Chlamydomonas Homologue of the t Complex-encoded Protein Tctex2, Is Essential for Outer Dynein Arm Assembly

    Science.gov (United States)

    Pazour, Gregory J.; Koutoulis, Anthony; Benashski, Sharon E.; Dickert, Bethany L.; Sheng, Hong; Patel-King, Ramila S.; King, Stephen M.; Witman, George B.

    1999-01-01

    Tctex2 is thought to be one of the distorter genes of the mouse t haplotype. This complex greatly biases the segregation of the chromosome that carries it such that in heterozygous +/t males, the t haplotype is transmitted to >95% of the offspring, a phenomenon known as transmission ratio distortion. The LC2 outer dynein arm light chain of Chlamydomonas reinhardtii is a homologue of the mouse protein Tctex2. We have identified Chlamydomonas insertional mutants with deletions in the gene encoding LC2 and demonstrate that the LC2 gene is the same as the ODA12 gene, the product of which had not been identified previously. Complete deletion of the LC2/ODA12 gene causes loss of all outer arms and a slow jerky swimming phenotype. Transformation of the deletion mutant with the cloned LC2/ODA12 gene restores the outer arms and rescues the motility phenotype. Therefore, LC2 is required for outer arm assembly. The fact that LC2 is an essential subunit of flagellar outer dynein arms allows us to propose a detailed mechanism whereby transmission ratio distortion is explained by the differential binding of mutant (t haplotype encoded) and wild-type dyneins to the axonemal microtubules of t-bearing or wild-type sperm, with resulting differences in their motility. PMID:10512883

  2. Co-precipitation of phosphate and iron limits mitochondrial phosphate availability in Saccharomyces cerevisiae lacking the yeast frataxin homologue (YFH1).

    Science.gov (United States)

    Seguin, Alexandra; Santos, Renata; Pain, Debkumar; Dancis, Andrew; Camadro, Jean-Michel; Lesuisse, Emmanuel

    2011-02-25

    Saccharomyces cerevisiae cells lacking the yeast frataxin homologue (Δyfh1) accumulate iron in the mitochondria in the form of nanoparticles of ferric phosphate. The phosphate content of Δyfh1 mitochondria was higher than that of wild-type mitochondria, but the proportion of mitochondrial phosphate that was soluble was much lower in Δyfh1 cells. The rates of phosphate and iron uptake in vitro by isolated mitochondria were higher for Δyfh1 than wild-type mitochondria, and a significant proportion of the phosphate and iron rapidly became insoluble in the mitochondrial matrix, suggesting co-precipitation of these species after oxidation of iron by oxygen. Increasing the amount of phosphate in the medium decreased the amount of iron accumulated by Δyfh1 cells and improved their growth in an iron-dependent manner, and this effect was mostly transcriptional. Overexpressing the major mitochondrial phosphate carrier, MIR1, slightly increased the concentration of soluble mitochondrial phosphate and significantly improved various mitochondrial functions (cytochromes, [Fe-S] clusters, and respiration) in Δyfh1 cells. We conclude that in Δyfh1 cells, soluble phosphate is limiting, due to its co-precipitation with iron.

  3. Initial characterization of a bolA homologue from Pseudomonas fluorescens indicates different roles for BolA-like proteins in P. fluorescens and Escherichia coli.

    Science.gov (United States)

    Koch, Birgit; Nybroe, Ole

    2006-09-01

    The RpoS-regulated bolA gene in Escherichia coli is important for the decrease in cell size during stationary phase or sudden carbon starvation. A Pseudomonas fluorescens strain mutated in a gene with homology to bolA reduced its cell size upon carbon starvation, and RpoS had little effect on bolA expression. The mutant grew slower than the wild-type strain in minimal medium with L-serine as the sole nitrogen source, while growth rates were similar on a mixture of L-serine and L-cysteine. Reverse transcriptase polymerase chain reaction analysis indicated that the bolA homologue is the second gene in an operon where the two next ORFs encode putative proteins with homology to sulphurtransferases and protein disulphide isomerases. Complementation of the mutant phenotypes was only obtained by plasmids encoding BolA as well as the above two proteins. Growth phenotypes and gene homologies suggest that BolA-like proteins have different functions in E. coli and Pseudomonas.

  4. SLAH1, a homologue of the slow type anion channel SLAC1, modulates shoot Cl − accumulation and salt tolerance in Arabidopsis thaliana

    KAUST Repository

    Qiu, Jiaen

    2016-06-23

    Salinity tolerance is correlated with shoot chloride (Cl–) exclusion in multiple crops, but the molecular mechanisms of long-distance Cl– transport are poorly defined. Here, we characterize the in planta role of AtSLAH1 (a homologue of the slow type anion channel-associated 1 (SLAC1)). This protein, localized to the plasma membrane of root stelar cells, has its expression reduced by salt or ABA, which are key predictions for a protein involved with loading Cl– into the root xylem. Artificial microRNA knockdown mutants of AtSLAH1 had significantly reduced shoot Cl− accumulation when grown under low Cl–, whereas shoot Cl– increased and the shoot nitrate/chloride ratio decreased following AtSLAH1 constitutive or stelar-specific overexpression when grown in high Cl–. In both sets of overexpression lines a significant reduction in shoot biomass over the null segregants was observed under high Cl– supply, but not low Cl– supply. Further in planta data showed AtSLAH3 overexpression increased the shoot nitrate/chloride ratio, consistent with AtSLAH3 favouring nitrate transport. Heterologous expression of AtSLAH1 in Xenopus laevis oocytes led to no detectible transport, suggesting the need for post-translational modifications for AtSLAH1 to be active. Our in planta data are consistent with AtSLAH1 having a role in controlling root-to-shoot Cl– transport.

  5. Re-fraction: a machine learning approach for deterministic identification of protein homologues and splice variants in large-scale MS-based proteomics.

    Science.gov (United States)

    Yang, Pengyi; Humphrey, Sean J; Fazakerley, Daniel J; Prior, Matthew J; Yang, Guang; James, David E; Yang, Jean Yee-Hwa

    2012-05-04

    A key step in the analysis of mass spectrometry (MS)-based proteomics data is the inference of proteins from identified peptide sequences. Here we describe Re-Fraction, a novel machine learning algorithm that enhances deterministic protein identification. Re-Fraction utilizes several protein physical properties to assign proteins to expected protein fractions that comprise large-scale MS-based proteomics data. This information is then used to appropriately assign peptides to specific proteins. This approach is sensitive, highly specific, and computationally efficient. We provide algorithms and source code for the current version of Re-Fraction, which accepts output tables from the MaxQuant environment. Nevertheless, the principles behind Re-Fraction can be applied to other protein identification pipelines where data are generated from samples fractionated at the protein level. We demonstrate the utility of this approach through reanalysis of data from a previously published study and generate lists of proteins deterministically identified by Re-Fraction that were previously only identified as members of a protein group. We find that this approach is particularly useful in resolving protein groups composed of splice variants and homologues, which are frequently expressed in a cell- or tissue-specific manner and may have important biological consequences.

  6. Structural studies on a non toxic homologue of type II RIPs from bitter gourd: Molecular basis of non toxicity, conformational selection and glycan structure

    Indian Academy of Sciences (India)

    Thyageshwar Chandran; Alok Sharma; M Vijayan

    2015-12-01

    The structures of nine independent crystals of bitter gourd seed lectin (BGSL), a non-toxic homologue of type II RIPS, and its sugar complexes have been determined. The four-chain, two-fold symmetric, protein is made up of two identical two-chain modules, each consisting of a catalytic chain and a lectin chain, connected by a disulphide bridge. The lectin chain is made up of two domains. Each domain carries a carbohydrate binding site in type II RIPS of known structure. BGSL has a sugar binding site only on one domain, thus impairing its interaction at the cell surface. The adenine binding site in the catalytic chain is defective. Thus, defects in sugar binding as well as adenine binding appear to contribute to the non-toxicity of the lectin. The plasticity of the molecule is mainly caused by the presence of two possible well defined conformations of a surface loop in the lectin chain. One of them is chosen in the sugar complexes, in a case of conformational selection, as the chosen conformation facilitates an additional interaction with the sugar, involving an arginyl residue in the loop. The -glycosylation of the lectin involves a plant-specific glycan while that in toxic type H RIPS of known structure involves a glycan which is animal as well as plant specific.

  7. CDX2 Inhibits Invasion and Migration of Gastric Cancer Cells by Phosphatase and Tensin Homologue Deleted from Chromosome 10/Akt Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Yong-Qiang Liu

    2015-01-01

    Full Text Available Background: Gastric cancer (GC is one of the most prevalent malignancies in the world today, with a high mortality rate. CDX2 is a Drosophila caudal-related homeobox transcription factor that plays an important role in GC. Phosphatase and tensin homologue deleted from chromosome 10 (PTEN is an important tumor suppressor which is widely expressed in normal human tissues. The aim of the study was to determine the relationship and mechanism between CDX2 and PTEN in invasion and migration of GC cells. Methods: pcDNA3-CDX2 plasmids were transfected into MGC-803 cells to up-regulate CDX2 protein, and small interfering RNA-CDX2 was transfected to down-regulate CDX2. The influence of CDX2 or PTEN on cell migration and invasion was measured by invasion, migration and wound healing assays. Western blotting assay and immunofluorescence were used to detect the expression of CDX2, PTEN, phosphorylation of Akt, E-cadherin and N-cadherin. Statistical significance was determined by one-way analysis of variance. Results: The results showed that CDX2 reduced the migration and invasion of GC cells (P < 0.05, and inhibited the activity of Akt through down-regulating PTEN expression (P < 0.05. CDX2 also restrained epithelial-mesenchymal transition of GC cells. Conclusions: CDX2 inhibited invasion and migration of GC cells by PTEN/Akt signaling pathway, and that may be used for potential therapeutic target.

  8. A novel C-terminal homologue of Aha1 co-chaperone binds to heat shock protein 90 and stimulates its ATPase activity in Entamoeba histolytica.

    Science.gov (United States)

    Singh, Meetali; Shah, Varun; Tatu, Utpal

    2014-04-17

    Cytosolic heat shock protein 90 (Hsp90) has been shown to be essential for many infectious pathogens and is considered a potential target for drug development. In this study, we have carried out biochemical characterization of Hsp90 from a poorly studied protozoan parasite of clinical importance, Entamoeba histolytica. We have shown that Entamoeba Hsp90 can bind to both ATP and its pharmacological inhibitor, 17-AAG (17-allylamino-17-demethoxygeldanamycin), with Kd values of 365.2 and 10.77 μM, respectively, and it has a weak ATPase activity with a catalytic efficiency of 4.12×10(-4) min(-1) μM(-1). Using inhibitor 17-AAG, we have shown dependence of Entamoeba on Hsp90 for its growth and survival. Hsp90 function is regulated by various co-chaperones. Previous studies suggest a lack of several important co-chaperones in E. histolytica. In this study, we describe the presence of a novel homologue of co-chaperone Aha1 (activator of Hsp90 ATPase), EhAha1c, lacking a canonical Aha1 N-terminal domain. We also show that EhAha1c is capable of binding and stimulating ATPase activity of EhHsp90. In addition to highlighting the potential of Hsp90 inhibitors as drugs against amoebiasis, our study highlights the importance of E. histolytica in understanding the evolution of Hsp90 and its co-chaperone repertoire.

  9. Physicochemical studies on ion-pair amphiphiles: Solution and interfacial behaviour of systems derived from sodium dodecylsulfate and -alkyltrimethylammonium bromide homologues

    Indian Academy of Sciences (India)

    Kajari Maiti; Subhash C Bhattacharya; Satya P Moulik; Amiya K Panda

    2010-11-01

    Bulk and interfacial properties of ion-pair amphiphiles (IPA), formed between sodium dodecylsulfate (SDS) and -alkyltrimethylammonium bromide homologues (CTAB; = 10, 12, 14, 16, and 18), have been investigated. Different phases and aggregated states, formed in the ternary combinations of CTAB/SDS/H2O, have been identified and described. Equimolar mixture of IPAs in water yielded precipitates, in the form of coacervates. Aqueous solubility of isolated coacervates in presence and absence of additives like cholesterol and bile salts have been examined. The isolated coacervates have been characterized by 1H NMR, FTIR, X-ray diffraction (XRD), differential scanning calorimetry (DSC) and polarization microscopic measurements. The coacervates have appeared in the shape of needle and complex flower-like aggregates. Surface pressure ()-area (A) isotherm of the coacervates at the air/water interface have been constructed and compared with the lipid 1,2-dipalmitoyl--glycero-3-phosphocholine (DPPC). Morphologies of the IPA monolayers at different surface pressures have been also examined by epifluorescence microscopy. The compressed interfacial monolayers have produced spherical (both regular and irregular) and fern-leaf like domains.

  10. Isolation of new genes in distal Xq28: transcriptional map and identification of a human homologue of the ARD1 N-acetyl transferase of Saccharomyces cerevisiae.

    Science.gov (United States)

    Tribioli, C; Mancini, M; Plassart, E; Bione, S; Rivella, S; Sala, C; Torri, G; Toniolo, D

    1994-07-01

    In this paper, we describe the physical and transcriptional organization of a region of 140 kb in Xq28, 5' to the L1CAM gene. By isolation and mapping of CpG islands to the physical map of the region, isolation of cDNAs, determination of partial nucleotide sequences and study of the pattern of expression and of the orientation of the transcripts identified we have established a transcriptional map of this region. In this map, previously identified genes (L1CAM, V2R, HCF1 and RnBP) have been positioned as well as 3 new genes. All genes in the region are rather small, ranging in size from 2 to 30 kb, and very close to one another. With the exception of the V2R gene, they are housekeeping, have a CpG island at their 5' end and the same orientation of transcription. This kind of organization is consistent with the one previously described for the more distal portion of Xq28, between the Color Vision (CV) and the G6PD genes and indicates that genes with housekeeping and tissue specific pattern of expression are interspersed in the genome but they are probably found in different 'transcriptional domains'. Among the new genes, TE2 demonstrated 40% identity with the protein N-acetyl transferase ARD1 of S. cerevisiae: TE2 may be the human homologue of the S. cerevisiae gene.

  11. Identification of linear B-cell epitopes on myotoxin II, a Lys49 phospholipase A₂ homologue from Bothrops asper snake venom.

    Science.gov (United States)

    Lomonte, Bruno

    2012-10-01

    Knowledge on toxin immunogenicity at the molecular level can provide valuable information for the improvement of antivenoms, as well as for understanding toxin structure-function relationships. The aims of this study are two-fold: first, to identify the linear B-cell epitopes of myotoxin II from Bothrops asper snake venom, a Lys49 phospholipase A₂ homologue; and second, to use antibodies specifically directed against an epitope having functional relevance in its toxicity, to probe the dimeric assembly mode of this protein in solution. Linear B-cell epitopes were identified using a library of overlapping synthetic peptides spanning its complete sequence. Epitopes recognized by a rabbit antiserum to purified myotoxin II, and by three batches of a polyvalent (Crotalidae) therapeutic antivenom (prepared in horses immunized with a mixture of B. asper, Crotalus simus, and Lachesis stenophrys venoms) were mapped using an enzyme-immunoassay based on the capture of biotinylated peptides by immobilized streptavidin. Some of the epitopes identified were shared between the two species, whereas others were unique. Differences in epitope recognition were observed not only between the two species, but also within the three batches of equine antivenom. Epitope V, located at the C-terminal region of this protein, is known to be relevant for toxicity and neutralization. Affinity-purified rabbit antibodies specific for this site were able to immunoprecipitate myotoxin II, suggesting that the two copies of epitope V are simultaneously available to antibody binding, which would be compatible with the mode of dimerization known as "conventional" dimer.

  12. The PAM1 gene of petunia, required for intracellular accommodation and morphogenesis of arbuscular mycorrhizal fungi, encodes a homologue of VAPYRIN.

    Science.gov (United States)

    Feddermann, Nadja; Muni, Rajasekhara Reddy Duvvuru; Zeier, Tatyana; Stuurman, Jeroen; Ercolin, Flavia; Schorderet, Martine; Reinhardt, Didier

    2010-11-01

    Most terrestrial plants engage into arbuscular mycorrhizal (AM) symbiosis with fungi of the phylum Glomeromycota. The initial recognition of the fungal symbiont results in the activation of a symbiosis signalling pathway that is shared with the root nodule symbiosis (common SYM pathway). The subsequent intracellular accommodation of the fungus, and the elaboration of its characteristic feeding structures, the arbuscules, depends on a genetic programme in the plant that has recently been shown to involve the VAPYRIN gene in Medicaco truncatula. We have previously identified a mutant in Petunia hybrida, penetration and arbuscule morphogenesis 1 (pam1), that is defective in the intracellular stages of AM development. Here, we report on the cloning of PAM1, which encodes a VAPYRIN homologue. PAM1 protein localizes to the cytosol and the nucleus, with a prominent affinity to mobile spherical structures that are associated with the tonoplast, and are therefore referred to as tonospheres. In mycorrhizal roots, tonospheres were observed in the vicinity of intracellular hyphae, where they may play an essential role in the accommodation and morphogenesis of the fungal endosymbiont.

  13. The CD11a partner in Sus scrofa lymphocyte function-associated antigen-1 (LFA-1: mRNA cloning, structure analysis and comparison with mammalian homologues

    Directory of Open Access Journals (Sweden)

    Thomas Anne VT

    2005-10-01

    Full Text Available Abstract Background Lymphocyte function-associated antigen-1 (LFA-1, CD11a/CD18, alphaLbeta2, the most abundant and widely expressed beta2-integrin, is required for many cellular adhesive interactions during the immune response. Many studies have shown that LFA-1 is centrally involved in the pathogenesis of several diseases caused by Repeats-in-toxin (RTX -producing bacteria. Results The porcine-LFA-1 CD11a (alpha subunit coding sequence was cloned, sequenced and compared with the available mammalian homologues in this study. Despite some focal differences, it shares all the main characteristics of these latter. Interestingly, as in sheep and humans, an allelic variant with a triplet insertion resulting in an additional Gln-744 was consistently identified, which suggests an allelic polymorphism that might be biologically relevant. Conclusion Together with the pig CD18-encoding cDNA, which has been available for a long time, the sequence data provided here will allow the successful expression of porcine CD11a, thus giving the first opportunity to express the Sus scrofa beta2-integrin LFA-1 in vitro as a tool to examine the specificities of inflammation in the porcine species.

  14. Robust identification of orthologues and paralogues for microbial pan-genomics using GET_HOMOLOGUES: a case study of pIncA/C plasmids.

    Science.gov (United States)

    Vinuesa, Pablo; Contreras-Moreira, Bruno

    2015-01-01

    GET_HOMOLOGUES is an open-source software package written in Perl and R to define robust core- and pan-genomes by computing consensus clusters of orthologous gene families from whole-genome sequences using the bidirectional best-hit, COGtriangles, and OrthoMCL clustering algorithms. The granularity of the clusters can be fine-tuned by a user-configurable filtering strategy based on a combination of blastp pairwise alignment parameters, hmmscan-based scanning of Pfam domain composition of the proteins in each cluster, and a partial synteny criterion. We present detailed protocols to fit exponential and binomial mixture models to estimate core- and pan-genome sizes, compute pan-genome trees from the pan-genome matrix using a parsimony criterion, analyze and graphically represent the pan-genome structure, and identify lineage-specific gene families for the 12 complete pIncA/C plasmids currently available in NCBI's RefSeq. The software package, license, and detailed user manual can be downloaded for free for academic use from two mirrors: http://www.eead.csic.es/compbio/soft/gethoms.php and http://maya.ccg.unam.mx/soft/gethoms.php.

  15. Rasputin, the Drosophila homologue of the RasGAP SH3 binding protein, functions in ras- and Rho-mediated signaling.

    Science.gov (United States)

    Pazman, C; Mayes, C A; Fanto, M; Haynes, S R; Mlodzik, M

    2000-04-01

    The small GTPase Ras plays an important role in many cellular signaling processes. Ras activity is negatively regulated by GTPase activating proteins (GAPs). It has been proposed that RasGAP may also function as an effector of Ras activity. We have identified and characterized the Drosophila homologue of the RasGAP-binding protein G3BP encoded by rasputin (rin). rin mutants are viable and display defects in photoreceptor recruitment and ommatidial polarity in the eye. Mutations in rin/G3BP genetically interact with components of the Ras signaling pathway that function at the level of Ras and above, but not with Raf/MAPK pathway components. These interactions suggest that Rin is required as an effector in Ras signaling during eye development, supporting an effector role for RasGAP. The ommatidial polarity phenotypes of rin are similar to those of RhoA and the polarity genes, e.g. fz and dsh. Although rin/G3BP interacts genetically with RhoA, affecting both photoreceptor differentiation and polarity, it does not interact with the gain-of-function genotypes of fz and dsh. These data suggest that Rin is not a general component of polarity generation, but serves a function specific to Ras and RhoA signaling pathways.

  16. The Drosophila deoxyhypusine hydroxylase homologue nero and its target eIF5A are required for cell growth and the regulation of autophagy.

    Science.gov (United States)

    Patel, Prajal H; Costa-Mattioli, Mauro; Schulze, Karen L; Bellen, Hugo J

    2009-06-29

    Hypusination is a unique posttranslational modification by which lysine is transformed into the atypical amino acid hypusine. eIF5A (eukaryotic initiation factor 5A) is the only known protein to contain hypusine. In this study, we describe the identification and characterization of nero, the Drosophila melanogaster deoxyhypusine hydroxylase (DOHH) homologue. nero mutations affect cell and organ size, bromodeoxyuridine incorporation, and autophagy. Knockdown of the hypusination target eIF5A via RNA interference causes phenotypes similar to nero mutations. However, loss of nero appears to cause milder phenotypes than loss of eIF5A. This is partially explained through a potential compensatory mechanism by which nero mutant cells up-regulate eIF5A levels. The failure of eIF5A up-regulation to rescue nero mutant phenotypes suggests that hypusination is required for eIF5A function. Furthermore, expression of enzymatically impaired forms of DOHH fails to rescue nero clones, indicating that hypusination activity is important for nero function. Our data also indicate that nero and eIF5A are required for cell growth and affect autophagy and protein synthesis.

  17. Cloning of the cDNA for a human homologue of the Drosophila white gene and mapping to chromosome 21q22.3

    Energy Technology Data Exchange (ETDEWEB)

    Haiming Chen; Lalioti, M.D.; Perrin, G.; Antonarakis, S.E. [Univ. of Geneva Medical School (Switzerland)] [and others

    1996-07-01

    In an effort to contribute to the transcript map of human chromosome 21 and the understanding of the pathophysiology of trisomy 21, we have used exon trapping to identify fragments of chromosome 21 genes. Two trapped exons, from pools of chromosome 21-specific cosmids, showed homology to the Drosophila white (w) gene. We subsequently cloned the corresponding cDNA for a human homologue of the Drosophila w gene (hW) from human retina and fetal brain cDNA libraries. The gene belongs to the ATP-binding cassette transporter gene family and is homologous to Drosophila w (and to 2 genes from other species) and to a lesser extent to Drosophila brown (bw) and scarlet (st) genes that are all involved in the transport of eye pigment precursor molecules. A DNA polymorphism with 62% heterozygosity due to variation of a poly (T) region in the 3{prime} UTR of the hW has been identified and used for the incorporation of this gene to the genetic map of chromosome 21. The hW is located at 21q22.3 between DNA markers D21S212 and D21S49 in a P1 clone that also contains marker BCEI. The gene is expressed at various levels in many human tissues. The contributions of this gene to the Down syndrome phenotypes, to human eye color, and to the resulting phenotypes of null or missense mutations are presently unknown. 56 refs., 8 figs., 1 tab.

  18. Recombinant vacuolar iron transporter family homologue PfVIT from human malaria-causing Plasmodium falciparum is a Fe2+/H+exchanger

    Science.gov (United States)

    Labarbuta, Paola; Duckett, Katie; Botting, Catherine H.; Chahrour, Osama; Malone, John; Dalton, John P.; Law, Christopher J.

    2017-01-01

    Vacuolar iron transporters (VITs) are a poorly understood family of integral membrane proteins that can function in iron homeostasis via sequestration of l