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Sample records for ii alpha subunit

  1. Isolation and characterization of recombinant human casein kinase II subunits alpha and beta from bacteria

    DEFF Research Database (Denmark)

    Grankowski, N; Boldyreff, B; Issinger, O G

    1991-01-01

    cDNA encoding the casein kinase II (CKII) subunits alpha and beta of human origin were expressed in Escherichia coli using expression vector pT7-7. Significant expression was obtained with E. coli BL21(DE3). The CKII subunits accounted for approximately 30% of the bacterial protein; however, most...... of the expressed proteins were produced in an insoluble form. The recombinant CKII alpha subunit was purified by DEAE-cellulose chromatography, followed by phosphocellulose and heparin-agarose chromatography. The recombinant CKII beta subunit was extracted from the insoluble pellet and purified in a single step...... on phosphocellulose. From 10 g bacterial cells, the yield of soluble protein was 12 mg alpha subunit and 5 mg beta subunit. SDS/PAGE analysis of the purified recombinant proteins indicated molecular masses of 42 kDa and 26 kDa for the alpha and beta subunits, respectively, in agreement with the molecular masses...

  2. Role of glycine residues highly conserved in the S2-S3 linkers of domains I and II of voltage-gated calcium channel alpha(1) subunits.

    Science.gov (United States)

    Teng, Jinfeng; Iida, Kazuko; Ito, Masanori; Izumi-Nakaseko, Hiroko; Kojima, Itaru; Adachi-Akahane, Satomi; Iida, Hidetoshi

    2010-05-01

    The pore-forming component of voltage-gated calcium channels, alpha(1) subunit, contains four structurally conserved domains (I-IV), each of which contains six transmembrane segments (S1-S6). We have shown previously that a Gly residue in the S2-S3 linker of domain III is completely conserved from yeasts to humans and important for channel activity. The Gly residues in the S2-S3 linkers of domains I and II, which correspond positionally to the Gly in the S2-S3 linker of domain III, are also highly conserved. Here, we investigated the role of the Gly residues in the S2-S3 linkers of domains I and II of Ca(v)1.2. Each of the Gly residues was replaced with Glu or Gln to produce mutant Ca(v)1.2s; G182E, G182Q, G579E, G579Q, and the resulting mutants were transfected into BHK6 cells. Whole-cell patch-clamp recordings showed that current-voltage relationships of the four mutants were the same as those of wild-type Ca(v)1.2. However, G182E and G182Q showed significantly smaller current densities because of mislocalization of the mutant proteins, suggesting that Gly(182) in domain I is involved in the membrane trafficking or surface expression of alpha(1) subunit. On the other hand, G579E showed a slower voltage-dependent current inactivation (VDI) compared to Ca(v)1.2, although G579Q showed a normal VDI, implying that Gly(579) in domain II is involved in the regulation of VDI and that the incorporation of a negative charge alters the VDI kinetics. Our findings indicate that the two conserved Gly residues are important for alpha(1) subunit to become functional.

  3. Drosophila casein kinase I alpha regulates homolog pairing and genome organization by modulating condensin II subunit Cap-H2 levels.

    Science.gov (United States)

    Nguyen, Huy Q; Nye, Jonathan; Buster, Daniel W; Klebba, Joseph E; Rogers, Gregory C; Bosco, Giovanni

    2015-01-01

    The spatial organization of chromosomes within interphase nuclei is important for gene expression and epigenetic inheritance. Although the extent of physical interaction between chromosomes and their degree of compaction varies during development and between different cell-types, it is unclear how regulation of chromosome interactions and compaction relate to spatial organization of genomes. Drosophila is an excellent model system for studying chromosomal interactions including homolog pairing. Recent work has shown that condensin II governs both interphase chromosome compaction and homolog pairing and condensin II activity is controlled by the turnover of its regulatory subunit Cap-H2. Specifically, Cap-H2 is a target of the SCFSlimb E3 ubiquitin-ligase which down-regulates Cap-H2 in order to maintain homologous chromosome pairing, chromosome length and proper nuclear organization. Here, we identify Casein Kinase I alpha (CK1α) as an additional negative-regulator of Cap-H2. CK1α-depletion stabilizes Cap-H2 protein and results in an accumulation of Cap-H2 on chromosomes. Similar to Slimb mutation, CK1α depletion in cultured cells, larval salivary gland, and nurse cells results in several condensin II-dependent phenotypes including dispersal of centromeres, interphase chromosome compaction, and chromosome unpairing. Moreover, CK1α loss-of-function mutations dominantly suppress condensin II mutant phenotypes in vivo. Thus, CK1α facilitates Cap-H2 destruction and modulates nuclear organization by attenuating chromatin localized Cap-H2 protein.

  4. Drosophila casein kinase I alpha regulates homolog pairing and genome organization by modulating condensin II subunit Cap-H2 levels.

    Directory of Open Access Journals (Sweden)

    Huy Q Nguyen

    Full Text Available The spatial organization of chromosomes within interphase nuclei is important for gene expression and epigenetic inheritance. Although the extent of physical interaction between chromosomes and their degree of compaction varies during development and between different cell-types, it is unclear how regulation of chromosome interactions and compaction relate to spatial organization of genomes. Drosophila is an excellent model system for studying chromosomal interactions including homolog pairing. Recent work has shown that condensin II governs both interphase chromosome compaction and homolog pairing and condensin II activity is controlled by the turnover of its regulatory subunit Cap-H2. Specifically, Cap-H2 is a target of the SCFSlimb E3 ubiquitin-ligase which down-regulates Cap-H2 in order to maintain homologous chromosome pairing, chromosome length and proper nuclear organization. Here, we identify Casein Kinase I alpha (CK1α as an additional negative-regulator of Cap-H2. CK1α-depletion stabilizes Cap-H2 protein and results in an accumulation of Cap-H2 on chromosomes. Similar to Slimb mutation, CK1α depletion in cultured cells, larval salivary gland, and nurse cells results in several condensin II-dependent phenotypes including dispersal of centromeres, interphase chromosome compaction, and chromosome unpairing. Moreover, CK1α loss-of-function mutations dominantly suppress condensin II mutant phenotypes in vivo. Thus, CK1α facilitates Cap-H2 destruction and modulates nuclear organization by attenuating chromatin localized Cap-H2 protein.

  5. Drosophila Casein Kinase I Alpha Regulates Homolog Pairing and Genome Organization by Modulating Condensin II Subunit Cap-H2 Levels

    Science.gov (United States)

    Nguyen, Huy Q.; Nye, Jonathan; Buster, Daniel W.; Klebba, Joseph E.; Rogers, Gregory C.; Bosco, Giovanni

    2015-01-01

    The spatial organization of chromosomes within interphase nuclei is important for gene expression and epigenetic inheritance. Although the extent of physical interaction between chromosomes and their degree of compaction varies during development and between different cell-types, it is unclear how regulation of chromosome interactions and compaction relate to spatial organization of genomes. Drosophila is an excellent model system for studying chromosomal interactions including homolog pairing. Recent work has shown that condensin II governs both interphase chromosome compaction and homolog pairing and condensin II activity is controlled by the turnover of its regulatory subunit Cap-H2. Specifically, Cap-H2 is a target of the SCFSlimb E3 ubiquitin-ligase which down-regulates Cap-H2 in order to maintain homologous chromosome pairing, chromosome length and proper nuclear organization. Here, we identify Casein Kinase I alpha (CK1α) as an additional negative-regulator of Cap-H2. CK1α-depletion stabilizes Cap-H2 protein and results in an accumulation of Cap-H2 on chromosomes. Similar to Slimb mutation, CK1α depletion in cultured cells, larval salivary gland, and nurse cells results in several condensin II-dependent phenotypes including dispersal of centromeres, interphase chromosome compaction, and chromosome unpairing. Moreover, CK1α loss-of-function mutations dominantly suppress condensin II mutant phenotypes in vivo. Thus, CK1α facilitates Cap-H2 destruction and modulates nuclear organization by attenuating chromatin localized Cap-H2 protein. PMID:25723539

  6. Potentiation of prolactin secretion following lactotrope escape from dopamine action. II. Phosphorylation of the alpha(1) subunit of L-type, voltage-dependent calcium channels.

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    Hernández, M E; del Mar Hernández, M; Díaz-Muñoz, M; Clapp, C; de la Escalera, G M

    1999-07-01

    Modulation of Ca(2+) channels has been shown to alter cellular functions. It can play an important role in the amplification of signals in the endocrine system, including the pleiotropically regulated pituitary lactotropes. Prolactin (PRL) secretion is tonically inhibited by dopamine (DA), the escape from which triggers acute episodes of hormone secretion. The magnitude of these episodes is explained by a potentiation of the PRL-releasing action of secretagogues such as thyrotropin-releasing hormone (TRH). While the mechanisms of this potentiation are not fully understood, it is known to be mimicked by the dihydropyridine, L-type Ca(2+) channel agonist Bay K 8644 and blocked by nifedipine and methoxyverapamil. The potentiation is also blocked by inhibitors of cyclic AMP-dependent protein kinase and protein kinase C. We recently described that the escape from tonic actions of DA results in increased macroscopic Ca(2+) currents in GH(4)C(1) lactotropic clonal cells transfected with a cDNA encoding the long form of the human D(2)-DA receptor. Here we show that the withdrawal from DA potentiates the PRL-releasing action of TRH in GH(4)C(1)/D(2)-DAR cells to the same extent as in enriched lactotropes in primary culture. In both experimental models a low density of dihydropyridine receptors was shown by (+)-[(3)H]PN200-110 binding. Photoaffinity labelling with the dihydropyridine [(3)H]azidopine revealed a protein consistent with the alpha(1) subunit of L-type Ca(2+) channels of 165-170 kDa. In both experimental models, the facilitation of TRH action triggered by the escape from DA was correlated with an enhanced rate of phosphorylation of this putative alpha(1) subunit, the nature of which was further supported by immunoprecipitation with selective antibodies directed against the alpha(1C) and alpha(1D) subunit of voltage-gated calcium channels. We propose that PKA- and PKC-dependent phosphorylation of the alpha(1) subunit of high voltage activated, L-type Ca(2

  7. Comparative Analysis of Eubacterial DNA Polymerase Ⅲ Alpha Subunits

    Institute of Scientific and Technical Information of China (English)

    Xiao-Qian Zhao; Jian-Fei Hu; Jun Yu

    2006-01-01

    DNA polymerase Ⅲ is one of the five eubacterial DNA polymerases that is responsible for the replication of DNA duplex. Among the ten subunits of the DNA polymerase Ⅲ core enzyme, the alpha subunit catalyzes the reaction for polymerizing both DNA strands. In this study, we extracted genomic sequences of the alpha subunit from 159 sequenced eubacterial genomes, and carried out sequencebased phylogenetic and structural analyses. We found that all eubacterial genomes have one or more alpha subunits, which form either homodimers or heterodimers.Phylogenetic and domain structural analyses as well as copy number variations of the alpha subunit in each bacterium indicate the classification of alpha subunit into four basic groups: polC, dnaE1, dnaE2, and dnaE3. This classification is of essence in genome composition analysis. We also consolidated the naming convention to avoid further confusion in gene annotations.

  8. Hypersecretion of the alpha-subunit in clinically non-functioning pituitary adenomas: Diagnostic accuracy is improved by adding alpha-subunit/gonadotropin ratio to levels of alpha-subunit

    DEFF Research Database (Denmark)

    Andersen, Marianne; Ganc-Petersen, Joanna; Jørgensen, Jens Otto Lunde;

    2010-01-01

    BACKGROUND: In vitro, the majority of clinically non-functioning pituitary adenomas (NFPAs) produce gonadotropins or their alpha-subunit; however, in vivo, measurements of alpha-subunit levels may not accurately detect the hypersecretion of the alpha-subunit. AIM: We wanted to estimate the refere......BACKGROUND: In vitro, the majority of clinically non-functioning pituitary adenomas (NFPAs) produce gonadotropins or their alpha-subunit; however, in vivo, measurements of alpha-subunit levels may not accurately detect the hypersecretion of the alpha-subunit. AIM: We wanted to estimate...... the reference intervals and decision limits for gonadotropin alpha-subunit, LH and FSH levels, and aratio (alpha-subunit/LH+FSH), especially taking into consideration patient gender and menstrual status. Furthermore, we wanted to examine if the diagnostic utility of alpha-subunit hypersecretion was improved...... patients with NFPAs. Gonadotropin alpha-subunit, LH and FSH levels were measured and alpha-ratios were calculated. RESULTS: In healthy adults, the cut-offs for alpha-subunit levels were significantly different between men and pre- and postmenopausal women: the cut-offs were 1.10, 0.48 and 3.76 IU...

  9. A genetic analysis of Plasmodium falciparum RNA polymerase II subunits in yeast.

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    Hazoume, Adonis; Naderi, Kambiz; Candolfi, Ermanno; Kedinger, Claude; Chatton, Bruno; Vigneron, Marc

    2011-04-01

    RNA polymerase II is an essential nuclear multi subunit enzyme that transcribes nearly the whole genome. Its inhibition by the alpha-amanitin toxin leads to cell death. The enzyme of Plasmodium falciparum remains poorly characterized. Using a complementation assay in yeast as a genetic test, we demonstrate that five Plasmodium putative RNA polymerase subunits are indeed functional in vivo. The active site of this enzyme is built from the two largest subunits. Using site directed mutagenesis we were able to modify the active site of the yeast RNA polymerase II so as to introduce Plasmodium or human structural motifs. The resulting strains allow the screening of chemical libraries for potential specific inhibitors.

  10. Integrin alpha(3)-subunit expression modulates alveolar epithelial cell monolayer formation.

    Science.gov (United States)

    Lubman, R L; Zhang, X L; Zheng, J; Ocampo, L; Lopez, M Z; Veeraraghavan, S; Zabski, S M; Danto, S I; Borok, Z

    2000-07-01

    We investigated expression of the alpha(3)-integrin subunit by rat alveolar epithelial cells (AECs) grown in primary culture as well as the effects of monoclonal antibodies with blocking activity against the alpha(3)-integrin subunit on AEC monolayer formation. alpha(3)-Integrin subunit mRNA and protein were detectable in AECs on day 1 and increased with time in culture. alpha(3)- and beta(1)-integrin subunits coprecipitated in immunoprecipitation experiments with alpha(3)- and beta(1)-subunit-specific antibodies, consistent with their association as the alpha(3)beta(1)-integrin receptor at the cell membrane. Treatment with blocking anti-alpha(3) monoclonal antibody from day 0 delayed development of transepithelial resistance, reduced transepithelial resistance through day 5 compared with that in untreated AECs, and resulted in large subconfluent patches in monolayers viewed by scanning electron microscopy on day 3. These data indicate that alpha(3)- and beta(1)-integrin subunits are expressed in AEC monolayers where they form the heterodimeric alpha(3)beta(1)-integrin receptor at the cell membrane. Blockade of the alpha(3)-integrin subunit inhibits formation of confluent AEC monolayers. We conclude that the alpha(3)-integrin subunit modulates formation of AEC monolayers by virtue of the key role of the alpha(3)beta(1)-integrin receptor in AEC adhesion.

  11. The beta subunit of casein kinase II

    DEFF Research Database (Denmark)

    Boldyreff, B; Piontek, K; Schmidt-Spaniol, I;

    1991-01-01

    cDNAs encoding the beta subunit of pig and mouse CKII were isolated. The porcine cDNA was expressed as a fusion protein in Escherichia coli and used for the production of anti-CKII-beta subunit specific antibodies....

  12. The Escherichia coli RNA polymerase alpha subunit and transcriptional activation by bacteriophage lambda CII protein.

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    Gabig, M; Obuchowski, M; Ciesielska, A; Latała, B; Wegrzyn, A; Thomas, M S; Wegrzyn, G

    1998-01-01

    Bacteriophage lambda is not able to lysogenise the Escherichia coli rpoA341 mutant. This mutation causes a single amino acid substitution Lys271Glu in the C-terminal domain of the RNA polymerase alpha subunit (alphaCTD). Our previous studies indicated that the impaired lysogenisation of the rpoA341 host is due to a defect in transcriptional activation by the phage CII protein and suggested a role for alphaCTD in this process. Here we used a series of truncation and point mutants in the rpoA gene placed on a plasmid to investigate the process of transcriptional activation by the cII gene product. Our results indicate that amino-acid residues 265, 268 and 271 in the a subunit may play an important role in the CII-mediated activation of the pE promoter (most probably residue 271) or may be involved in putative interactions between alphaCTD and an UP-like element near pE (most probably residues 265 and 268). Measurement of the activity of pE-lacZ, pI-lacZ and p(aQ)-lacZ fusions in the rpoA+ and rpoA341 hosts demonstrated that the mechanism of activation of these CII-dependent promoters may be in each case different.

  13. Editing modifies the GABA(A) receptor subunit alpha3

    DEFF Research Database (Denmark)

    Ohlson, Johan; Pedersen, Jakob Skou; Haussler, David

    2007-01-01

    Adenosine to inosine (A-to-I) pre-mRNA editing by the ADAR enzyme family has the potential to increase the variety of the proteome. This editing by adenosine deamination is essential in mammals for a functional brain. To detect novel substrates for A-to-I editing we have used an experimental method...... to find selectively edited sites and combined it with bioinformatic techniques that find stem-loop structures suitable for editing. We present here the first verified editing candidate detected by this screening procedure. We show that Gabra-3, which codes for the alpha3 subunit of the GABA(A) receptor......, is a substrate for editing by both ADAR1 and ADAR2. Editing of the Gabra-3 mRNA recodes an isoleucine to a methionine. The extent of editing is low at birth but increases with age, reaching close to 100% in the adult brain. We therefore propose that editing of the Gabra-3 mRNA is important for normal brain...

  14. Separation and characterization of alpha-chain subunits from tilapia (Tilapia zillii) skin gelatin using ultrafiltration.

    Science.gov (United States)

    Chen, Shulin; Tang, Lanlan; Su, Wenjin; Weng, Wuyin; Osako, Kazufumi; Tanaka, Munehiko

    2015-12-01

    Alpha-chain subunits were separated from tilapia skin gelatin using ultrafiltration, and the physicochemical properties of obtained subunits were investigated. As a result, α1-subunit and α2-subunit could be successfully separated by 100 kDa MWCO regenerated cellulose membranes and 150 kDa MWCO polyethersulfone membranes, respectively. Glycine was the most dominant amino acid in both α1-subunit and α2-subunit. However, the tyrosine content was higher in α2-subunit than in α1-subunit, resulting in strong absorption near 280 nm observed in the UV absorption spectrum. Based on the DSC analysis, it was found that the glass transition temperatures of gelatin, α1-subunit and α2-subunit were 136.48 °C, 126.77 °C and 119.43 °C, respectively. Moreover, the reduced viscosity and denaturation temperature of α1-subunit were higher than those of α2-subunit, and the reduced viscosity reached the highest when α-subunits were mixed with α1/α2 ratio of approximately 2, suggesting that α1-subunit plays a more important role in the thermostability of gelatin than α2-subunit.

  15. Genetics Home Reference: mucolipidosis II alpha/beta

    Science.gov (United States)

    ... Health Conditions mucolipidosis II alpha/beta mucolipidosis II alpha/beta Enable Javascript to view the expand/collapse ... PDF Open All Close All Description Mucolipidosis II alpha/beta (also known as I-cell disease) is ...

  16. A revised model for AMP-activated protein kinase structure: The alpha-subunit binds to both the beta- and gamma-subunits although there is no direct binding between the beta- and gamma-subunits.

    Science.gov (United States)

    Wong, Kelly A; Lodish, Harvey F

    2006-11-24

    The 5'-AMP-activated protein kinase (AMPK) is a master sensor for cellular metabolic energy state. It is activated by a high AMP/ATP ratio and leads to metabolic changes that conserve energy and utilize alternative cellular fuel sources. The kinase is composed of a heterotrimeric protein complex containing a catalytic alpha-subunit, an AMP-binding gamma-subunit, and a scaffolding beta-subunit thought to bind directly both the alpha- and gamma-subunits. Here, we use coimmunoprecipitation of proteins in transiently transfected cells to show that the alpha2-subunit binds directly not only to the beta-subunit, confirming previous work, but also to the gamma1-subunit. Deletion analysis of the alpha2-subunit reveals that the C-terminal 386-552 residues are sufficient to bind to the beta-subunit. The gamma1-subunit binds directly to the alpha2-subunit at two interaction sites, one within the catalytic domain consisting of alpha2 amino acids 1-312 and a second within residues 386-552. Binding of the alpha2 and the gamma1-subunits was not affected by 400 mum AMP or ATP. Furthermore, we show that the beta-subunit C terminus is essential for binding to the alpha2-subunit but, in contrast to previous work, the beta-subunit does not bind directly to the gamma1-subunit. Taken together, this study presents a new model for AMPK heterotrimer structure where through its C terminus the beta-subunit binds to the alpha-subunit that, in turn, binds to the gamma-subunit. There is no direct interaction between the beta- and gamma-subunits.

  17. Prefrontal GABA(A) receptor alpha-subunit expression in normal postnatal human development and schizophrenia.

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    Duncan, Carlotta E; Webster, Maree J; Rothmond, Debora A; Bahn, Sabine; Elashoff, Michael; Shannon Weickert, Cynthia

    2010-07-01

    Cortical GABA deficits that are consistently reported in schizophrenia may reflect an etiology of failed normal postnatal neurotransmitter maturation. Previous studies have found prefrontal cortical GABA(A) receptor alpha subunit alterations in schizophrenia, yet their relationship to normal developmental expression profiles in the human cortex has not been determined. The aim of this study was to quantify GABA(A) receptor alpha-subunit mRNA expression patterns in human dorsolateral prefrontal cortex (DLPFC) during normal postnatal development and in schizophrenia cases compared to controls. Transcript levels of GABA(A) receptor alpha subunits were measured using microarray and qPCR analysis of 60 normal individuals aged 6weeks to 49years and in 37 patients with schizophrenia/schizoaffective disorder and 37 matched controls. We detected robust opposing changes in cortical GABA(A) receptor alpha1 and alpha5 subunits during the first few years of postnatal development, with a 60% decrease in alpha5 mRNA expression and a doubling of alpha1 mRNA expression with increasing age. In our Australian schizophrenia cohort we detected decreased GAD67 mRNA expression (p=0.0012) and decreased alpha5 mRNA expression (p=0.038) in the DLPFC with no significant change of other alpha subunits. Our findings confirm that GABA deficits (reduced GAD67) are a consistent feature of schizophrenia postmortem brain studies. Our study does not confirm alterations in cortical alpha1 or alpha2 mRNA levels in the schizophrenic DLPFC, as seen in previous studies, but instead we report a novel down-regulation of alpha5 subunit mRNA suggesting that post-synaptic alterations of inhibitory receptors are an important feature of schizophrenia but may vary between cohorts. Copyright 2009 Elsevier Ltd. All rights reserved.

  18. First inactive conformation of CK2 alpha, the catalytic subunit of protein kinase CK2

    DEFF Research Database (Denmark)

    Raaf, Jennifer; Issinger, Olaf-Georg; Niefind, Karsten

    2009-01-01

    (EPKs). To function as regulatory key components, EPKs normally exist in inactive ground states and are activated only upon specific signals. Typically, this activation is accompanied by large conformational changes in helix alpha C and in the activation segment, leading to a characteristic arrangement......The Ser/Thr kinase casein kinase 2 (CK2) is a heterotetrameric enzyme composed of two catalytic chains (CK2alpha, catalytic subunit of CK2) attached to a dimer of two noncatalytic subunits (CK2beta, noncatalytic subunit of CK2). CK2alpha belongs to the superfamily of eukaryotic protein kinases...... of catalytic key elements. For CK2alpha, however, no strict physiological control of activity is known. Accordingly, CK2alpha was found so far exclusively in the characteristic conformation of active EPKs, which is, in this case, additionally stabilized by a unique intramolecular contact between the N...

  19. Functional protein expression of multiple sodium channel alpha- and beta-subunit isoforms in neonatal cardiomyocytes.

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    Kaufmann, Susann G; Westenbroek, Ruth E; Zechner, Christoph; Maass, Alexander H; Bischoff, Sebastian; Muck, Jenny; Wischmeyer, Erhard; Scheuer, Todd; Maier, Sebastian K G

    2010-01-01

    Voltage-gated sodium channels are composed of pore-forming alpha- and auxiliary beta-subunits and are responsible for the rapid depolarization of cardiac action potentials. Recent evidence indicates that neuronal tetrodotoxin (TTX) sensitive sodium channel alpha-subunits are expressed in the heart in addition to the predominant cardiac TTX-resistant Na(v)1.5 sodium channel alpha-subunit. These TTX-sensitive isoforms are preferentially localized in the transverse tubules of rodents. Since neonatal cardiomyocytes have yet to develop transverse tubules, we determined the complement of sodium channel subunits expressed in these cells. Neonatal rat ventricular cardiomyocytes were stained with antibodies specific for individual isoforms of sodium channel alpha- and beta-subunits. alpha-actinin, a component of the z-line, was used as an intracellular marker of sarcomere boundaries. TTX-sensitive sodium channel alpha-subunit isoforms Na(v)1.1, Na(v)1.2, Na(v)1.3, Na(v)1.4 and Na(v)1.6 were detected in neonatal rat heart but at levels reduced compared to the predominant cardiac alpha-subunit isoform, Na(v)1.5. Each of the beta-subunit isoforms (beta1-beta4) was also expressed in neonatal cardiac cells. In contrast to adult cardiomyocytes, the alpha-subunits are distributed in punctate clusters across the membrane surface of neonatal cardiomyocytes; no isoform-specific subcellular localization is observed. Voltage clamp recordings in the absence and presence of 20 nM TTX provided functional evidence for the presence of TTX-sensitive sodium current in neonatal ventricular myocardium which represents between 20 and 30% of the current, depending on membrane potential and experimental conditions. Thus, as in the adult heart, a range of sodium channel alpha-subunits are expressed in neonatal myocytes in addition to the predominant TTX-resistant Na(v)1.5 alpha-subunit and they contribute to the total sodium current.

  20. Cloning and sequencing of the casein kinase 2 alpha subunit from Zea mays

    DEFF Research Database (Denmark)

    Dobrowolska, G; Boldyreff, B; Issinger, O G

    1991-01-01

    The nucleotide sequence of the cDNA coding for the alpha subunit of casein kinase 2 of Zea mays has been determined. The cDNA clone contains an open reading frame of 996 nucleotides encoding a polypeptide comprising 332 amino acids. The primary amino acid sequence exhibits 75% identity to the alpha...

  1. Characterization of the alpha and beta subunits of casein kinase 2 by far-UV CD spectroscopy

    DEFF Research Database (Denmark)

    Issinger, O G; Brockel, C; Boldyreff, B;

    1992-01-01

    Although Chou-Fasman calculations of the secondary structure of recombinant casein kinase 2 subunits alpha and beta suggest they have a similar overall conformation, circular dichroism (CD) studies show that substantial differences in the conformation of the two subunits exist. In addition......, no changes in the far-UV CD spectrum of the alpha subunit are observed in the presence of casein or the synthetic decapeptide substrate RRRDDDSDDD. Furthermore, the alpha-helical structure of the alpha subunit (but not the beta subunit) can be increased in the presence of stoichiometric amounts of heparin...

  2. Mapping of a liver phosphorylase kinase [alpha]-subunit gene on the mouse x chromosome

    Energy Technology Data Exchange (ETDEWEB)

    Geng, Yan; Derry, J.M.J.; Barnard, P.J. (MRC Molecular Neurobiology Unit, Cambridge (United Kingdom)); Hendrickx, J.; Coucke, P.; Willems, P.R. (Univ. of Antwerp (Belgium))

    1993-01-01

    Phosphorylase kinase (PHK) is a regulatory enzyme of the glycogenolytic pathway composed of a complex of four subunits. We recently mapped the muscle [alpha]-subunit gene (Phka) to the mouse X chromosome in a region syntenic with the proximal long arm of the human X chromosome and containing the human homologue of this gene, PHKA. We now report the mapping of the liver [alpha]-subunit gene to the telomeric end of the mouse X chromosome. This mapping position would suggest a location for the human liver [alpha]-subunit gene on the proximal short arm of the X chromosome, a region recently implicated in X-linked liver glycogenosis (XLG). 20 refs., 2 figs.

  3. The alpha3 laminin subunit, alpha6beta4 and alpha3beta1 integrin coordinately regulate wound healing in cultured epithelial cells and in the skin

    DEFF Research Database (Denmark)

    Goldfinger, L E; Hopkinson, S B; deHart, G W

    1999-01-01

    Previously, we demonstrated that proteolytic processing within the globular domain of the alpha3 subunit of laminin-5 (LN5) converts LN5 from a cell motility-inducing factor to a protein complex that can trigger the formation of hemidesmosomes, certain cell-matrix attachment sites found in epithe......-inhibiting antibodies, we provide evidence that LN5 and its two integrin receptors (alpha6beta4 and alpha3beta1) appear necessary for wound healing to occur in MCF-10A cell culture wounds. We propose a model for healing of wounded epithelial tissues based on these results....... in epithelial cells. We have prepared a monoclonal antibody (12C4) whose epitope is located toward the carboxy terminus of the globular domain of the alpha3 laminin subunit. This epitope is lost from the alpha3 subunit as a consequence of proteolytic processing. Antibody 12C4 stains throughout the matrix...... the wound site. A similar phenomenon is observed in human skin wounds, since we also detect expression of the unprocessed alpha3 laminin subunit at the leading tip of the sheet of epidermal cells that epithelializes skin wounds in vivo. In addition, using alpha3 laminin subunit and integrin function...

  4. Heterogeneity of the alpha subunit of tubulin and the variability of tubulin within a single organism.

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    Bibring, T; Baxandall, J; Denslow, S; Walker, B

    1976-05-01

    When tubulins obtained from particular microtubules of the sea urchin (ciliary doublet A tubules, flagellar doublet microtubules, and mitotic microtubules) are analyzed by electrophoresis in a polyacrylamide gel system containing sodium dodecyl sulfate and urea, heterogeneity of the alpha subunit, and differences between the tubulins are revealed. The alpha subunit of tubulin from mitotic apparatus and from A microtubules of ciliary doublets is resolved into two bands, while the alpha subunit of flagellar doublet tubulin gives a single band. The mitotic and ciliary tubulins differ in the mobilities of their two alpha species, or in the relative amounts present, or both. The existence of differences between the tubulins has been confirmed by a preliminary analysis of their cyanogen bromide peptides.

  5. The thermal structural transition of alpha-crystallin modulates subunit interactions and increases protein solubility.

    Directory of Open Access Journals (Sweden)

    Giuseppe Maulucci

    Full Text Available BACKGROUND: Alpha crystallin is an oligomer composed of two types of subunits, alpha-A and alpha-B crystallin, and is the major constituent of human lens. The temperature induced condensation of alpha-crystallin, the main cause for eye lens opacification (cataract, is a two step-process, a nucleation followed by an aggregation phase, and a protective effect towards the aggregation is exhibited over the alpha crystallin phase transition temperature (Tc = 318.16 K. METHODS/RESULTS: To investigate if a modulation of the subunit interactions over Tc could trigger the protective mechanism towards the aggregation, we followed, by using simultaneously static and dynamic light scattering, the temperature induced condensation of alpha-crystallin. By developing a mathematical model able to uncouple the nucleation and aggregation processes, we find a previously unobserved transition in the nucleation rate constant. Its temperature dependence allows to determine fundamental structural parameters, the chemical potential (Δμ and the interfacial tension (γ of the aggregating phase, that characterize subunit interactions. CONCLUSIONS/GENERAL SIGNIFICANCE: The decrease of both Δμ and γ at Tc, and a relative increase in solubility, reveal a significative decrease in the strenght of alpha-crystallin subunits interactions, which protects from supramolecolar condensation in hypertermic conditions. On the whole, we suggest a general approach able to understand the structural and kinetic mechanisms involved in aggregation-related diseases and in drugs development and testing.

  6. The NH2-terminal php domain of the alpha subunit of the Escherichia coli replicase binds the epsilon proofreading subunit.

    Science.gov (United States)

    Wieczorek, Anna; McHenry, Charles S

    2006-05-05

    The alpha subunit of the replicase of all bacteria contains a php domain, initially identified by its similarity to histidinol phosphatase but of otherwise unknown function (Aravind, L., and Koonin, E. V. (1998) Nucleic Acids Res. 26, 3746-3752). Deletion of 60 residues from the NH2 terminus of the alpha php domain destroys epsilon binding. The minimal 255-residue php domain, estimated by sequence alignment with homolog YcdX, is insufficient for epsilon binding. However, a 320-residue segment including sequences that immediately precede the polymerase domain binds epsilon with the same affinity as the 1160-residue full-length alpha subunit. A subset of mutations of a conserved acidic residue (Asp43 in Escherichia coli alpha) present in the php domain of all bacterial replicases resulted in defects in epsilon binding. Using sequence alignments, we show that the prototypical gram+ Pol C, which contains the polymerase and proofreading activities within the same polypeptide chain, has an epsilon-like sequence inserted in a surface loop near the center of the homologous YcdX protein. These findings suggest that the php domain serves as a platform to enable coordination of proofreading and polymerase activities during chromosomal replication.

  7. Expression of G alpha 16, a G-protein alpha subunit specific for hematopoiesis in acute leukemia.

    Science.gov (United States)

    Pfeilstöcker, M; Karlic, H; Salamon, J; Krömer, E; Mühlberger, H; Pavlova, B; Selim, U; Tüchler, H; Fritsch, G; Kneissl, S; Heinz, R; Pitterman, E; Paukovits, M R

    1996-07-01

    G-proteins are essential in signal transduction pathways. A G-protein alpha subunit termed G alpha 16 was found to be exclusively expressed in hematopoietic cell lines. In cells derived from patients, G alpha 16 expression has been detected in progenitor- and pre-B ALL cells and also in peripheral blood stem cells (PBSC). In this study, we analyzed G alpha 16 expression using a RT-PCR technique by testing elutriated blood cells from normal donors, PBSC from breast cancer patients and bone marrow or peripheral blood cells from acute leukemia patients. Both of two ALL patients and 15/16 AML patients expressed G alpha 16. In elutriation experiments, G alpha 16 expression was found in fractions containing the highest number of precursor cells but was absent in mature T and B cell fractions. In addition, CD34-enriched PBSC were positive for G alpha 16 expression. Further in vitro experiments using the cell line KG1 showed that G alpha 16 expression was not affected by the growth inhibiting hemoregulatory peptide pEEDCK which has a sequence homology present within G alpha 16. Taken together, these data demonstrate that G alpha 16 is expressed in various normal and malignant hematopietic progenitors but not in their differentiated counterparts. G alpha 16 could play a vital role in signal transduction pathways controlling proliferation in early normal and malignant hematopoiesis.

  8. Folding, stability, and physical properties of the alpha subunit of bacterial luciferase.

    Science.gov (United States)

    Noland, B W; Dangott, L J; Baldwin, T O

    1999-12-01

    Bacterial luciferase is a heterodimeric (alphabeta) enzyme composed of homologous subunits. When the Vibrio harveyi luxA gene is expressed in Escherichia coli, the alpha subunit accumulates to high levels. The alpha subunit has a well-defined near-UV circular dichroism spectrum and a higher intrinsic fluorescence than the heterodimer, demonstrating fluorescence quenching in the enzyme which is reduced in the free subunit [Sinclair, J. F., Waddle, J. J., Waddill, W. F., and Baldwin, T. O. (1993) Biochemistry 32, 5036-5044]. Analytical ultracentrifugation of the alpha subunit has revealed a reversible monomer to dimer equilibrium with a dissociation constant of 14.9 +/- 4.0 microM at 18 degrees C in 50 mM phosphate and 100 mM NaCl, pH 7.0. The alpha subunit unfolded and refolded reversibly in urea-containing buffers by a three-state mechanism. The first transition occurred over the range of 0-2 M urea with an associated free-energy change of 2.24 +/- 0.25 kcal/mol at 18 degrees C in 50 mM phosphate buffer, pH 7.0. The second, occurring between 2.5 and 3.5 M urea, comprised a cooperative transition with a free-energy change of 6.50 +/- 0.75 kcal/mol. The intermediate species, populated maximally at ca. 2 M urea, has defined near-UV circular dichroism spectral properties distinct from either the native or the denatured states. The intrinsic fluorescence of the intermediate suggested that, although the quantum yield had decreased, the tryptophanyl residues remained largely buried. The far-UV circular dichroism spectrum of the intermediate indicated that it had lost ca. 40% of its native secondary structure. N-Terminal sequencing of the products of limited proteolysis of the intermediate showed that the C-terminal region of the alpha subunit became protease labile over the urea concentration range at which the intermediate was maximally populated. These observations have led us to propose an unfolding model in which the first transition is the unfolding of a C

  9. Homologous and unique G protein alpha subunits in the nematode Caenorhabditis elegans.

    Science.gov (United States)

    Lochrie, M A; Mendel, J E; Sternberg, P W; Simon, M I

    1991-01-01

    A cDNA corresponding to a known G protein alpha subunit, the alpha subunit of Go (Go alpha), was isolated and sequenced. The predicted amino acid sequence of C. elegans Go alpha is 80-87% identical to other Go alpha sequences. An mRNA that hybridizes to the C. elegans Go alpha cDNA can be detected on Northern blots. A C. elegans protein that crossreacts with antibovine Go alpha antibody can be detected on immunoblots. A cosmid clone containing the C. elegans Go alpha gene (goa-1) was isolated and mapped to chromosome I. The genomic fragments of three other C. elegans G protein alpha subunit genes (gpa-1, gpa-2, and gpa-3) have been isolated using the polymerase chain reaction. The corresponding cosmid clones were isolated and mapped to disperse locations on chromosome V. The sequences of two of the genes, gpa-1 and gpa-3, were determined. The predicted amino acid sequences of gpa-1 and gpa-3 are only 48% identical to each other. Therefore, they are likely to have distinct functions. In addition they are not homologous enough to G protein alpha subunits in other organisms to be classified. Thus C. elegans has G proteins that are identifiable homologues of mammalian G proteins as well as G proteins that appear to be unique to C. elegans. Study of identifiable G proteins in C. elegans may result in a further understanding of their function in other organisms, whereas study of the novel G proteins may provide an understanding of unique aspects of nematode physiology. Images PMID:1907494

  10. [The response of free alpha-subunit of glycoprotein hormones to LH-RH administration (author's transl)].

    Science.gov (United States)

    Hamamoto, T; Nishimura, R; Ashitaka, Y; Tojo, S

    1982-05-20

    The responses of immunoreactive free alpha-subunit of glycoprotein hormones to LH-RH administration were studied in normal men and women, and in patients with hypergonadotropic hypogonadism, hypogonadotropic hypogonadism, trophoblastic disease and isolated ectopic alpha-subunit producing tumor. In patients with hypergonadotropic hypergonadism, basal levels of serum alpha-subunit were elevated and the responses to LH-RH were also excessive compared to those of normal men and women. Conversely, in hypogonadotropic hypogonadism, basal levels of alpha-subunit were significantly low and its response to LH-RH was barely detectable. The response of alpha-subunit to constant intravenous infusion of LH-RH (1 microgram/kg/h) was studied in 4 normal men. Both LH and alpha-subunit revealed biphasic patterns of elevation. Its releasing pattern suggests the possibility that two pools of gonadotropin are involved in the production and secretion of alpha-subunit. In patients with trophoblastic disease secreting low levels of hCG (18 mIU/ml), the responses of alpha-subunit as well as pituitary gonadotropin to LH-RH were normal. However, in cases of high concentrations of hCG (1000 mIU/ml), the responses of alpha-subunit and gonadotropin were suppressed. After the administration of LH-RH to a patient with an isolated ectopic alpha-subunit producing tumor, the serum concentration of pituitary gonadotropin increased within the normal range, although that of alpha-subunit did not show a significant change. These results suggest that the production of alpha-subunit by tumors may be autonomous in contrast with a regulatory production in the pituitary.

  11. Stability of human chorionic gonadotropin and its alpha subunit in human blood.

    Science.gov (United States)

    Rao, C V; Hussa, R O; Carman, F R; Rinke, M L; Cook, C L; Yussman, M A

    1983-05-01

    The stability of human chorionic gonadotropin (hCG) and its alpha-subunit in whole blood, plasma, and serum under a variety of sample handling conditions commonly encountered in clinics, hospital wards, physician's offices, and clinical service laboratories was investigated with the use of radioreceptor assay, radioimmunoassays, as well as hormone integrity determinations. The results clearly demonstrate that hCG and its alpha-subunit are stable in unfrozen whole blood, plasma, and serum for at least 6 days and in frozen plasma and serum samples for at least 6 months. Repeated freezing and thawing of the samples during this period had no effect. Separation of plasma or serum from erythrocytes is not needed for at least 12 hours. Hemolysis in samples resulted in a 20% to 30% decrease in hCG and its alpha-subunit levels, which may be attributable to sample dilution.

  12. Analysis of Maxi-K alpha subunit splice variants in human myometrium

    Directory of Open Access Journals (Sweden)

    Morrison John J

    2004-09-01

    Full Text Available Abstract Background Large-conductance, calcium-activated potassium (Maxi-K channels are implicated in the modulation of human uterine contractions and myometrial Ca2+ homeostasis. However, the regulatory mechanism(s governing the expression of Maxi-K channels with decreased calcium sensitivity at parturition are unclear. The objectives of this study were to investigate mRNA expression of the Maxi-K alpha subunit, and that of its splice variants, in human non-pregnant and pregnant myometrium, prior to and after labour onset, to determine whether altered expression of these splice variants is associated with decreased calcium sensitivity observed at labour onset. Methods Myometrial biopsies were obtained at hysterectomy (non-pregnant, NP, and at Caesarean section, at elective (pregnant not-in-labour, PNL and intrapartum (pregnant in-labour, PL procedures. RNA was extracted from all biopsies and quantitative real-time RT-PCR was used to investigate for possible differential expression of the Maxi-K alpha subunit, and that of its splice variants, between these functionally-distinct myometrial tissue sets. Results RT-PCR analysis identified the presence of a 132 bp and an 87 bp spliced exon of the Maxi-K alpha subunit in all three myometrial tissue sets. Quantitative real-time PCR indicated a decrease in the expression of the Maxi-K alpha subunit with labour onset. While there was no change in the proportion of Maxi-K alpha subunits expressing the 87 bp spliced exon, the proportion of alpha subunits expressing the 132 bp spliced exon was significantly increased with labour onset, compared to both non-pregnant and pregnant not-in-labour tissues. An increased proportion of 132 bp exon-containing alpha subunit variants with labour onset is of interest, as channels expressing this spliced exon have decreased calcium and voltage sensitivities. Conclusions Our findings suggest that decreased Maxi-K alpha subunit mRNA expression in human myometrium at

  13. Translocation of a phycoerythrin alpha subunit across five biological membranes.

    Science.gov (United States)

    Gould, Sven B; Fan, Enguo; Hempel, Franziska; Maier, Uwe-G; Klösgen, Ralf Bernd

    2007-10-12

    Cryptophytes, unicellular algae, evolved by secondary endosymbiosis and contain plastids surrounded by four membranes. In contrast to cyanobacteria and red algae, their phycobiliproteins do not assemble into phycobilisomes and are located within the thylakoid lumen instead of the stroma. We identified two gene families encoding phycoerythrin alpha and light-harvesting complex proteins from an expressed sequence tag library of the cryptophyte Guillardia theta. The proteins bear a bipartite topogenic signal responsible for the transport of nuclear encoded proteins via the ER into the plastid. Analysis of the phycoerythrin alpha sequences revealed that more than half of them carry an additional, third topogenic signal comprising a twin arginine motif, which is indicative of Tat (twin arginine transport)-specific targeting signals. We performed import studies with several derivatives of one member using a diatom transformation system, as well as intact chloroplasts and thylakoid vesicles isolated from pea. We demonstrated the different targeting properties of each individual part of the tripartite leader and show that phycoerythrin alpha is transported across the thylakoid membrane into the thylakoid lumen and protease-protected. Furthermore, we showed that thylakoid transport of phycoerythrin alpha takes place by the Tat pathway even if the 36 amino acid long bipartite topogenic signal precedes the actual twin arginine signal. This is the first experimental evidence of a protein being targeted across five biological membranes.

  14. Characterisation of the tryptophan synthase alpha subunit in maize

    Directory of Open Access Journals (Sweden)

    Gierl Alfons

    2008-04-01

    Full Text Available Abstract Background In bacteria, such as Salmonella typhimurium, tryptophan is synthesized from indole-3-glycerole phosphate (IGP by a tryptophan synthase αββα heterotetramer. Plants have evolved multiple α (TSA and β (TSB homologs, which have probably diverged in biological function and their ability of subunit interaction. There is some evidence for a tryptophan synthase (TS complex in Arabidopsis. On the other hand maize (Zea mays expresses the TSA-homologs BX1 and IGL that efficiently cleave IGP, independent of interaction with TSB. Results In order to clarify, how tryptophan is synthesized in maize, two TSA homologs, hitherto uncharacterized ZmTSA and ZmTSAlike, were functionally analyzed. ZmTSA is localized in plastids, the major site of tryptophan biosynthesis in plants. It catalyzes the tryptophan synthase α-reaction (cleavage of IGP, and forms a tryptophan synthase complex with ZmTSB1 in vitro. The catalytic efficiency of the α-reaction is strongly enhanced upon complex formation. A 160 kD tryptophan synthase complex was partially purified from maize leaves and ZmTSA was identified as native α-subunit of this complex by mass spectrometry. ZmTSAlike, for which no in vitro activity was detected, is localized in the cytosol. ZmTSAlike, BX1, and IGL were not detectable in the native tryptophan synthase complex in leaves. Conclusion It was demonstrated in vivo and in vitro that maize forms a tryptophan synthase complex and ZmTSA functions as α-subunit in this complex.

  15. An antisense oligodeoxynucleotide that depletes RI alpha subunit of cyclic AMP-dependent protein kinase induces growth inhibition in human cancer cells.

    Science.gov (United States)

    Yokozaki, H; Budillon, A; Tortora, G; Meissner, S; Beaucage, S L; Miki, K; Cho-Chung, Y S

    1993-02-15

    Enhanced expression of the RI alpha subunit of cyclic AMP-dependent protein kinase type I has been correlated with cancer cell growth. We provide evidence that RI alpha is a growth-inducing protein that may be essential for neoplastic cell growth. Human colon, breast, and gastric carcinoma and neuroblastoma cell lines exposed to a 21-mer human RI alpha antisense phosphorothioate oligodeoxynucleotide (S-oligodeoxynucleotide) exhibited growth inhibition with no sign of cytotoxicity. Mismatched sequence (random) S-oligodeoxynucleotides of the same length exhibited no effect. The growth inhibitory effect of RI alpha antisense oligomer correlated with a decrease in the RI alpha mRNA and protein levels and with an increase in RII beta (the regulatory subunit of protein kinase type II) expression. The growth inhibition was abolished, however, when cells were exposed simultaneously to both RI alpha and RII beta antisense S-oligodeoxynucleotides. The RII beta antisense S-oligodeoxynucleotide alone, exhibiting suppression of RII beta along with enhancement of RI alpha expression, led to slight stimulation of cell growth. These results demonstrate that two isoforms of cyclic AMP receptor proteins, RI alpha and RII beta, are reciprocally related in the growth control of cancer cells and that the RI alpha antisense oligodeoxynucleotide, which efficiently depletes the growth stimulatory RI alpha, is a powerful biological tool toward suppression of malignancy.

  16. An increased expression of Ca(2+) channel alpha(1A) subunit immunoreactivity in deep cerebellar neurons of rolling mouse Nagoya.

    Science.gov (United States)

    Sawada, K; Sakata-Haga, H; Ando, M; Takeda, N; Fukui, Y

    2001-12-01

    Rolling mouse Nagoya (RMN) is an ataxic mutant and carries a mutation in the gene coding for the alpha(1A) subunit of the P/Q-type Ca(2+) channel. We examined the immunohistochemical expression of the alpha(1A) subunit in deep cerebellar nuclei of RMN. The antibody used recognized residues 865-883 of the mouse alpha(1A) subunit not overlapping the altered sequences in RMN. In RMN, many neurons exhibited definite alpha(1A) subunit-staining in the medial nucleus, interposed nucleus, and lateral nucleus of deep cerebellar nuclei. The number of positive neurons in these nuclei was significantly higher in RMN than in controls. Increased expression of the alpha(1A) subunit in deep cerebellar neurons might compensate for the altered function of the P/Q-type Ca(2+) channel of RMN.

  17. Stat2 binding to the interferon-alpha receptor 2 subunit is not required for interferon-alpha signaling.

    Science.gov (United States)

    Nguyen, Vinh-Phúc; Saleh, Abu Z M; Arch, Allison E; Yan, Hai; Piazza, Flavia; Kim, John; Krolewski, John J

    2002-03-22

    The interferon-alpha (IFNalpha) receptor consists of two subunits, the IFNalpha receptor 1 (IFNaR1) and 2 (IFNaR2) chains. Following ligand binding, IFNaR1 is phosphorylated on tyrosine 466, and this site recruits Stat2 via its SH2 domain. In contrast, IFNaR2 binds Stat2 constitutively. In this study we have characterized the Stat2-IFNaR2 interaction and examined its role in IFNalpha signaling. Stat2 binds the major IFNaR2 protein but not a variant containing a shorter cytoplasmic domain. The interaction does not require a STAT SH2 domain. Both tyrosine-phosphorylated and non-phosphorylated Stat2 bind IFNaR2 in vitro; however, relatively little phosphorylated Stat2 associates with IFNaR2 in vivo. In vitro binding assays defined IFNaR2 residues 418-444 as the minimal interaction domain and site-specific mutation of conserved acidic residues within this domain disrupted in vitro and in vivo binding. An IFNaR2 construct carrying these mutations was either (i) overexpressed in 293T cells or (ii) used to complement IFNaR2-deficient U5A cells. Unexpectedly, the activity of an IFNalpha-dependent reporter gene was not reduced but, instead, was enhanced up to 2-fold. This suggests that this particular IFNaR2-Stat2 interaction is not required for IFNalpha signaling, but might act to negatively inhibit signaling. Finally, a doubly truncated recombinant fragment of Stat2, spanning residues 136-702, associated with IFNaR2 in vitro, indicating that the interaction with IFNaR2 is direct and occurs in a central region of Stat2 marked by a hydrophobic core.

  18. Structural determinants within residues 180-199 of the rodent. alpha. 5 nicotinic acetylcholine receptor subunit involved in. alpha. -bungarotoxin binding

    Energy Technology Data Exchange (ETDEWEB)

    McLane, K.E.; Xiadong Wu; Conti-Tronconi, B.M. (Univ. of Minnesota, St. Paul (United States))

    1991-11-05

    Synthetic peptides corresponding to sequence segments of the nicotinic acetylcholine receptor (nAChR) {alpha} subunits have been used to identify regions that contribute to formation of the binding sites for cholinergic ligands. The authors have previously defined {alpha}-bungarotoxin ({alpha}-BTX) binding sequences between residues 180 and 199 of a putative rat neuronal nAChR {alpha} subunit, designated {alpha}5, and between residues 181 and 200 of the chick neuronal {alpha}7 and {alpha}8 subunits. These sequences are relatively divergent compared with the Torpedo and muscle nAChR {alpha}1 {alpha}-BTX binding sites, which indicates a serious limitation of predicting functional domains of proteins based on homology in general. Given the highly divergent nature of the {alpha}5 sequence, they were interested in determining the critical amino acid residues for {alpha}-BTX binding. In the present study, the effects of single amino acid substitutions of Gly or Ala for each residue of the rat {alpha}(180-199) sequence were tested, using a competition assay, in which peptides compete for {sup 125}I-{alpha}-BTX binding with native Torpedo nAChR. These results indicate that a disulfide bridge between the vicinal cysteines at positions 191 and 192 of the {alpha}5 sequence is not an absolute requirement for {alpha}-BTX binding activity.

  19. Carbohydrate composition of the alpha-subunit of human choriogonadotropin (hCG alpha) and the free alpha molecules produced in pregnancy: most free alpha and some combined hCG alpha molecules are fucosylated.

    Science.gov (United States)

    Blithe, D L

    1990-06-01

    The carbohydrate compositions of pregnancy-derived hCG alpha (dissociated from intact hCG) and free alpha-subunit were analyzed using a combination of chemical analysis, lectin affinity chromatography, and glycosidase sensitivity. For direct compositional analysis, parallel samples were hydrolyzed in trifluoroacetic acid and analyzed for sialic acid and neutral sugars without prior derivatization. Separation of the monosaccharides was achieved by HPLC on a Dionex CarboPac column eluted at high pH, and the resolved monosaccharides were quantified by pulsed amperometric detection. The amounts of sugar that were found relative to peptide indicated the presence of two N-linked oligosaccharides per molecule on both hCG alpha and free alpha. Free alpha contained 2.5-fold higher amounts of sialic acid and galactose as well as a higher amount of N-acetylglucosamine than did hCG alpha. Free alpha also contained a 6-fold higher amount of fucose than did hCG alpha (1.2 vs. 0.2 residues of fucose/molecule). Serial fractionation of intact hCG alpha and free alpha molecules by lectin affinity chromatography indicated that virtually all of the hCG alpha-subunits contained at least one Concanavalin-A (Con-A)-binding site, whereas as many as 32% of the free alpha molecules could not bind to Con-A. Chromatography on Lens culinaris (Lch) resulted in 12% binding of hCG alpha and approximately 72% binding of free alpha (80-85% of the Con-A-bound free alpha and 47-48% of the Con-A-nonbound free alpha bound to Lch). Endoglycosidase-H (endo-H) treatment of hCG alpha released a portion of the oligosaccharides. The endo-H-released material appeared to be a monoantennary hybrid based on DEAE-binding properties and carbohydrate composition. In contrast to hCG alpha, free alpha was completely resistant to endo-H treatment. Incubation of endo-H-resistant hCG alpha with glycopeptidase-A resulted in the release of two components, which could be separated into monoantennary and biantennary

  20. Change in location and processing of inhibin alpha-subunit precursors during sexual maturation of the Djungarian hamster testis.

    Science.gov (United States)

    Tuohimaa, P; Bläuer, M; Bergmann, M; Aumüller, G

    1993-02-01

    Immunohistochemical location and immunoblot of inhibin alpha-subunit peptides were analyzed in the testis of the Djungarian hamster from days 0-31 of postnatal development using a specific antibody. An intense immunoreaction was observed in the centrally located T1 prespermatogonia at day 0. The staining intensity decreased gradually in the spermatogonia when they make contact with the basal lamina at days 8-10. At days 13 and 15 there is no staining. Thereafter the immunoreactivity in Sertoli cells as well as in A spermatogonia gradually increased, being highest in sexually mature animals. The intensity of alpha-subunit staining in the seminiferous tubules was stage specific, being strongest at stages III and IV. Immunoblot analysis of testis homogenates with the anti-INH alpha 1-32 antibody showed several bands: 88K, 80K, and 43K in immature hamster testis (0-, 2-, 6-, 8-, or 10-day-old). In the adult hamster (31-day-old) 88K, 80K, 28K, and 20K bands were seen, but no 43K band. Dimeric inhibin was not detected. The 43-44K band most likely corresponds to the pro-alpha N alpha C, the 28K band to intermediate forms between alpha N alpha C and alpha C (alpha I alpha C), and the 20K band to mature alpha-subunit (alpha C). The shift from the immature pattern to mature occurs at about 20 days of age. Freezing of the samples was deleterious to alpha C, since it could be detected only in freshly homogenized samples. The results suggest that prespermatogonia produce predominantly monomeric alpha-subunit precursor pro-alpha N alpha C, whereas the mature Sertoli cells as well as A spermatogonia contain mainly monomeric alpha I alpha C. The alpha-inhibin precursors may act as auto-/paracrine regulators of spermatogenesis. Our results suggest that different alpha-subunit precursors, pro-alpha N alpha C and alpha I alpha C, might be involved in the differentiation and maintenance of spermatogenesis, respectively. The posttranslational processing of alpha-subunit precursors

  1. Unexpected high digestion rate of cooked starch by the Ct-Maltase-Glucoamylase small intestine mucosal alpha-glucosidase subunit

    Science.gov (United States)

    For starch digestion to glucose, two luminal alpha-amylases and four gut mucosal alpha-glucosidase subunits are employed. The aim of this research was to investigate, for the first time, direct digestion capability of individual mucosal alpha-glucosidases on cooked (gelatinized) starch. Gelatinized ...

  2. Dopaminergic modulation of sodium current in hippocampal neurons via cAMP-dependent phosphorylation of specific sites in the sodium channel alpha subunit.

    Science.gov (United States)

    Cantrell, A R; Smith, R D; Goldin, A L; Scheuer, T; Catterall, W A

    1997-10-01

    Phosphorylation of brain Na+ channel alpha subunits by cAMP-dependent protein kinase (PKA) decreases peak Na+ current in cultured brain neurons and in mammalian cells and Xenopus oocytes expressing cloned brain Na+ channels. We have studied PKA regulation of Na+ channel function by activation of D1-like dopamine receptors in acutely isolated hippocampal neurons using whole-cell voltage-clamp recording techniques. The D1 agonist SKF 81297 reversibly reduced peak Na+ current in a concentration-dependent manner. No changes in the voltage dependence or kinetics of activation or inactivation were observed. This effect was mediated by PKA, as it was mimicked by application of the PKA activator Sp-5, 6-dichloro-1-beta-D-ribofuranosylbenzimidazole-3', 5'-monophosphorothioate(cBIMPS) and was inhibited by the specific PKA inhibitor peptide PKAI5-24. cBIMPS had similar effects on type IIA brain Na+ channel alpha subunits expressed in tsA-201 cells, but no effect was observed on a mutant Na+ channel alpha subunit in which serine residues in five PKA phosphorylation sites in the intracellular loop connecting domains I and II (LI-II) had been replaced by alanine. A single mutation, S573A, similarly eliminated cBIMPS modulation. Thus, activation of D1-like dopamine receptors results in PKA-dependent phosphorylation of specific sites in LI-II of the Na+ channel alpha subunit, causing a reduction in Na+ current. Such modulation is expected to exert a profound influence on overall neuronal excitability. Dopaminergic input to the hippocampus from the mesocorticolimbic system may exert this influence in vivo.

  3. Synthetic. cap alpha. subunit peptide 125-147 of human nicotinic acetylcholine receptor induces antibodies to native receptor

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, D.J.; Griesmann, G.E.; Huang, Z.; Lennon, V.A.

    1986-03-05

    A synthetic peptide corresponding to residues 125-147 of the Torpedo acetylcholine receptor (AChR) ..cap alpha.. subunit proved to be a major antigenic region of the AChR. Rats inoculated with 50 ..mu..g of peptide (T ..cap alpha.. 125-147) developed T cell immunity and antibodies to native AChR and signs of experimental autoimmune myasthenia gravis. They report the synthesis and preliminary testing of a disulfide-looped peptide comprising residues 125-147 of the human AChR ..cap alpha.. subunit. Peptide H ..cap alpha.. 125-147 differs from T ..cap alpha.. 125-147 at residues 139 (Glu for Gln) and 143 (Ser for Thr). In immunoprecipitation assays, antibodies to Torpedo AChR bound /sup 125/I-labelled H..cap alpha.. 125-147 antibody bound H..cap alpha.. 125-147, but monoclonal antibodies to an immunodominant region of native AChR bound neither H..cap alpha.. 125-147 nor T ..cap alpha.. 125-147. Rats immunized with H ..cap alpha.. 125-147 produced anti-mammalian muscle AChR antibodies that induced modulation of AChRs from cultured human myotubes. Thus, region 125-147 of the human AChR ..cap alpha.. subunit is extracellular in muscle, and is both antigenic and immunogenic. It remains to be determined whether or not autoantibodies to this region may in part cause the weakness or myasthenia gravis in man.

  4. The Alpha Catalytic Subunit of Protein Kinase CK2 Is Required for Mouse Embryonic Development▿

    Science.gov (United States)

    Lou, David Y.; Dominguez, Isabel; Toselli, Paul; Landesman-Bollag, Esther; O'Brien, Conor; Seldin, David C.

    2008-01-01

    Protein kinase CK2 (formerly casein kinase II) is a highly conserved and ubiquitous serine/threonine kinase that is composed of two catalytic subunits (CK2α and/or CK2α′) and two CK2β regulatory subunits. CK2 has many substrates in cells, and key roles in yeast cell physiology have been uncovered by introducing subunit mutations. Gene-targeting experiments have demonstrated that in mice, the CK2β gene is required for early embryonic development, while the CK2α′ subunit appears to be essential only for normal spermatogenesis. We have used homologous recombination to disrupt the CK2α gene in the mouse germ line. Embryos lacking CK2α have a marked reduction in CK2 activity in spite of the presence of the CK2α′ subunit. CK2α−/− embryos die in mid-gestation, with abnormalities including open neural tubes and reductions in the branchial arches. Defects in the formation of the heart lead to hydrops fetalis and are likely the cause of embryonic lethality. Thus, CK2α appears to play an essential and uncompensated role in mammalian development. PMID:17954558

  5. Characterization of the alpha and beta subunits of casein kinase 2 by far-UV CD spectroscopy

    DEFF Research Database (Denmark)

    Issinger, O G; Brockel, C; Boldyreff, B

    1992-01-01

    , comparison of the far-UV CD spectrum of reconstituted CK-2 with the spectra of the subunits indicates that conformational changes occur in the backbone region upon association. Such changes may explain the increased enzyme activity of the holoenzyme relative to that of the alpha subunit itself. In contrast......, presumably by its binding to the polylysine stretch at amino acid positions 74-77. Heat denaturation experiments (25-90 degrees C) support the notion that heparin may provide a local protective function. A similar but much larger effect was also observed in the presence of the beta subunit only, which...... supports previous suggestions of a protective function for this subunit. These results indicate that the protection provided by the beta subunit and the increased enzyme activity of the holoenzyme may arise, in part, from a stabilization of the conformation of the enzyme complex and an increase in alpha...

  6. Evaluation of native GABA(A) receptors containing an alpha 5 subunit.

    Science.gov (United States)

    Li, M; Szabo, A; Rosenberg, H C

    2001-02-09

    The type A receptor for gamma-aminobutyric acid (GABA), or GABA(A) receptor, is a pentamer of highly variable quaternary structure. It includes two alpha subunits, drawn from a pool of six genes, which largely determine benzodiazepine pharmacology of the receptor. In brain sections, both [(3)H]RY-80 (ethyl-8-acetylene-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5a][1,4]benzodiazepine-3-carboxylate) and [(3)H]L-655,708 (ethyl (S)-11,12,13,13a-tetrahydro-7-methoxy-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylate), which are selective for the benzodiazepine site of alpha 5 subunit-containing receptors, showed high-affinity, specific binding, but to fewer regions than did the nonselective benzodiazepine, [(3)H]flunitrazepam. The pattern mirrored alpha 5 mRNA distribution, and was similar to that previously reported for [(3)H]L-655,708 binding. Displacement of [(3)H]RY-80 bound to hippocampal homogenates, and of [(3)H]flunitrazepam bound to cerebellar and hippocampal homogenates showed comparable displacement by flumazenil (K(i)'s 5--7 nM). However, the K(i)'s for diazepam and for clobazam to displace [(3)H]RY-80 binding in hippocampus were about fourfold higher than for [(3)H]flunitrazepam, and the K(i) for clonazepam was sixfold larger, suggesting that these benzodiazepine receptor agonists bind with relatively lower affinity at hippocampal alpha 5-containing receptors.

  7. Functional expression of the GABAA receptor alpha2 and alpha3 subunits at synapses between intercalated medial paracapsular neurons of mouse amygdala

    Directory of Open Access Journals (Sweden)

    Raffaella eGeracitano

    2012-05-01

    Full Text Available In the amygdala, GABAergic neurons in the intercalated medial paracapsular cluster (Imp have been suggested to play a key role in fear learning and extinction. These neurons project to the central amygdaloid nucleus and to other areas within and outside the amygdala. In addition, they give rise to local collaterals that innervate other neurons in the Imp. Several drugs, including benzodiazepines, are allosteric modulators of GABA-A receptors. Benzodiazepines have both anxiolytic and sedative actions, which are mediated through GABA-A receptors containing alpha2/3 and alpha1 subunits, respectively. To establish whether alpha1 or alpha2/3 subunits are expressed at Imp cell synapses, we used paired recordings of anatomically-identified Imp neurons and high resolution immunocytochemistry in the mouse. We observed that a selective alpha3 subunit agonist, TP003 (100 nM, significantly increased the decay time constant of the unitary IPSCs. A similar effect was also induced by zolpidem (10 microM or by diazepam (1 microM. In contrast, lower doses of zolpidem (0.1-1 microM did not significantly alter the kinetics of the unitary IPSCs. Accordingly, immunocytochemical experiments established that the alpha2 and alpha3, but not the alpha1 subunits of the GABA-A receptors, were present at Imp cell synapses of the mouse amygdala. These results define, for the first time, some of the functional GABA-A receptor subunits expressed at synapses of Imp cells. The data also provide an additional rationale to prompt the search of GABA-A receptor alpha3 selective ligands as improved anxiolytic drugs.

  8. Similarity and divergence between the RNA polymerase alpha subunits from hyperthermophilic Thermotoga maritima and mesophilic Escherichia coli bacteria.

    Science.gov (United States)

    Braun, Frederique; Marhuenda, Fanny B; Morin, Amelie; Guevel, Laetitia; Fleury, Fabrice; Takahashi, Masayuki; Sakanyan, Vehary

    2006-10-01

    The alpha subunit (alphaTm) of Thermotoga maritima RNA polymerase has been characterized to investigate its role in transcriptional regulation in one of the few known anaerobic hyperthermophilic bacteria. The highly thermostable alphaTm shares 54% similarity with its Escherichia coli analogue (alphaEc). The T. maritima rpoA gene coding the alpha subunit does not complement the thermosensitive rpoA112 mutation of E. coli. However, alphaTm and alphaEc show similar folding patterns as determined by circular dichroism. Purified alphaTm binds to the T. maritima PargGo promoter region (probably to a UP-element) and Arg282 appears to be crucial for DNA binding. The thermostable protein is also able to interact with transcription regulatory proteins, like ArgR from T. neapolitana or CRP from E. coli. These data indicate that the RNA polymerase alpha subunit might play a crucial role in the modulation of gene expression in hyperthermophiles.

  9. Formation of fluorescent proteins by the attachment of phycoerythrobilin to R-phycoerythrin alpha and beta apo-subunits.

    Science.gov (United States)

    Isailovic, Dragan; Sultana, Ishrat; Phillips, Gregory J; Yeung, Edward S

    2006-11-01

    Formation of fluorescent proteins was explored after incubation of recombinant apo-subunits of phycobiliprotein R-phycoerythrin with phycoerythrobilin chromophore. Alpha and beta apo-subunit genes of R-phycoerythrin from red algae Polisiphonia boldii were cloned in plasmid pET-21d(+). Hexahistidine-tagged alpha and beta apo-subunits were expressed in Escherichia coli. Although expressed apo-subunits formed inclusion bodies, fluorescent holo-subunits were constituted after incubation of E. coli cells with phycoerythrobilin. Holo-subunits contained both phycoerythrobilin and urobilin chromophores. Fluorescence and differential interference contrast microscopy showed polar location of holo-subunit inclusion bodies in bacterial cells. Cells containing fluorescent holo-subunits were several times brighter than control cells as found by fluorescence microscopy and flow cytometry. The addition of phycoerythrobilin to cells did not show cytotoxic effects, in contrast to expression of proteins in inclusion bodies. In an attempt to improve solubility, R-phycoerythrin apo-subunits were fused to maltose-binding protein and incubated with phycoerythrobilin both in vitro and in vivo. Highly fluorescent soluble fusion proteins containing phycoerythrobilin as the sole chromophore were formed. Fusion proteins were localized by fluorescence microscopy either throughout E. coli cells or at cell poles. Flow cytometry showed that cells containing fluorescent fusion proteins were up to 10 times brighter than control cells. Results indicate that fluorescent proteins formed by attachment of phycoerythrobilin to expressed apo-subunits of phycobiliproteins can be used as fluorescent probes for analysis of cells by microscopy and flow cytometry. A unique property of these fluorescent reporters is their utility in both properly folded (soluble) subunits and subunits aggregated in inclusion bodies.

  10. Molecular cloning of pituitary glycoprotein alpha-subunit and follicle stimulating hormone and chorionic gonadotropin beta-subunits from New World squirrel monkey and owl monkey.

    Science.gov (United States)

    Scammell, Jonathan G; Funkhouser, Jane D; Moyer, Felricia S; Gibson, Susan V; Willis, Donna L

    2008-02-01

    The goal of this study was to characterize the gonadotropins expressed in pituitary glands of the New World squirrel monkey (Saimiri sp.) and owl monkey (Aotus sp.). The various subunits were amplified from total RNA from squirrel monkey and owl monkey pituitary glands by reverse transcription-polymerase chain reaction and the deduced amino acid sequences compared to those of other species. Mature squirrel monkey and owl monkey glycoprotein hormone alpha-polypeptides (96 amino acids in length) were determined to be 80% homologous to the human sequence. The sequences of mature beta subunits of follicle stimulating hormone (FSHbeta) from squirrel monkey and owl monkey (111 amino acids in length) are 92% homologous to human FSHbeta. New World primate glycoprotein hormone alpha-polypeptides and FSHbeta subunits showed conservation of all cysteine residues and consensus N-linked glycosylation sites. Attempts to amplify the beta-subunit of luteinizing hormone from squirrel monkey and owl monkey pituitary glands were unsuccessful. Rather, the beta-subunit of chorionic gonadotropin (CG) was amplified from pituitaries of both New World primates. Squirrel monkey and owl monkey CGbeta are 143 and 144 amino acids in length and 77% homologous with human CGbeta. The greatest divergence is in the C terminus, where all four sites for O-linked glycosylation in human CGbeta, responsible for delayed metabolic clearance, are predicted to be absent in New World primate CGbetas. It is likely that CG secreted from pituitary of New World primates exhibits a relatively short half-life compared to human CG.

  11. Multi-colony stimulating activity of interleukin 5 (IL-5) on hematopoietic progenitors from transgenic mice that express IL-5 receptor alpha subunit constitutively

    OpenAIRE

    1995-01-01

    The interleukin 3 (IL-3), IL-5, and granulocyte/macrophage colony- stimulating factor receptors consist of a cytokine-specific alpha subunit and the common beta subunit. Whereas IL-3 stimulates various lineages of hematopoietic cells, including multipotential progenitors, IL-5 acts mainly as an eosinophil lineage-specific factor. To investigate whether the lineage specificity of IL-5 is due to restricted expression of the IL-5 receptor alpha subunit (IL-5R alpha), we generated transgenic mice...

  12. Stoichiometry of expressed alpha(4)beta(2)delta gamma-aminobutyric acid type A receptors depends on the ratio of subunit cDNA transfected.

    Science.gov (United States)

    Wagoner, Kelly R; Czajkowski, Cynthia

    2010-05-07

    The gamma-aminobutyric acid type A receptor (GABA(A)R) is the target of many depressants, including benzodiazepines, anesthetics, and alcohol. Although the highly prevalent alphabetagamma GABA(A)R subtype mediates the majority of fast synaptic inhibition in the brain, receptors containing delta subunits also play a key role, mediating tonic inhibition and the actions of endogenous neurosteroids and alcohol. However, the fundamental properties of delta-containing GABA(A)Rs, such as subunit stoichiometry, are not well established. To determine subunit stoichiometry of expressed delta-containing GABA(A)Rs, we inserted the alpha-bungarotoxin binding site tag in the alpha(4), beta(2), and delta subunit N termini. An enhanced green fluorescent protein tag was also inserted into the beta(2) subunit to shift its molecular weight, allowing us to separate subunits using SDS-PAGE. Tagged alpha(4)beta(2)delta GABA(A)Rs were expressed in HEK293T cells using various ratios of subunit cDNA, and receptor subunit stoichiometry was determined by quantitating fluorescent alpha-bungarotoxin bound to each subunit on Western blots of surface immunopurified tagged GABA(A)Rs. The results demonstrate that the subunit stoichiometry of alpha(4)beta(2)delta GABA(A)Rs is regulated by the ratio of subunit cDNAs transfected. Increasing the ratio of delta subunit cDNA transfected increased delta subunit incorporation into surface receptors with a concomitant decrease in beta(2) subunit incorporation. Because receptor subunit stoichiometry can directly influence GABA(A)R pharmacological and functional properties, considering how the transfection protocols used affect subunit stoichiometry is essential when studying heterologously expressed alpha(4)beta(2)delta GABA(A)Rs. Successful bungarotoxin binding site tagging of GABA(A)R subunits is a novel tool with which to accurately quantitate subunit stoichiometry and will be useful for monitoring GABA(A)R trafficking in live cells.

  13. The DFT-DVM theoretical study of the differences of quadrupole splitting and the iron electronic structure for the rough heme models for {alpha}- and {beta}-subunits in deoxyhemoglobin and for deoxymyoglobin

    Energy Technology Data Exchange (ETDEWEB)

    Yuryeva, E. I. [Institute of Solid State Chemistry of the Ural Branch of the Russian Academy of Sciences (Russian Federation); Oshtrakh, M. I., E-mail: oshtrakh@mail.utnet.ru [Ural State Technical University-UPI, Faculty of Physical Techniques and Devices for Quality Control (Russian Federation)

    2008-01-15

    Quantum chemical calculations of the iron electron structure and {sup 57}Fe quadrupole splitting were made by density functional theory and X{alpha} discrete variation method for the rough heme models for {alpha}- and {beta}-subunits in deoxyhemoglobin and for deoxymyoglobin accounting stereochemical differences of the active sites in native proteins. The calculations revealed differences of quadrupole splitting temperature dependences for three models indicating sensitivity of quadrupole splitting and Fe(II) electronic structure to small variations of iron stereochemistry.

  14. Altered alpha subunits in phenylalanyl-tRNA synthetases from p-fluorophenylalanine-resistant strains of Escherichis coli.

    Science.gov (United States)

    Hennecke, H; Böck, A

    1975-07-01

    Three different phenylalanyl-tRNA synthetases have been purified to near homogeneity, one from a wild-type strain of Escherichia coli and the others from two independently isolated p-fluorophenyalanine-resistant strains. The mutant enzymes were not able to use p-fluorophenylalanine as a substrate for activation and attachment to tRNA. They proved to be indistinguishable from the wild-type enzyme by several electrophoretic and immunological criteria. The alpha and beta subunits of all three enzymes have been prepared by a method described in this paper. The isolated subunits per se did not reveal any significant enzyme activity, but combined they were able to form active phenylalanyl tRNA synthetase after a defined reconstitution process. Mixed reconstitution experiments between wild-type and mutant subunits indicate that the mutant alpha subunit is responsible for p-fluorophenylalanine resistance and therefore seems to carry the phenylalanine-binding site or to participate in its formation.

  15. Effects of terpenoid precursor feeding on Catharanthus roseus hairy roots over-expressing the alpha or the alpha and beta subunits of anthranilate synthase.

    Science.gov (United States)

    Peebles, Christie A M; Hong, Seung-Beom; Gibson, Susan I; Shanks, Jacqueline V; San, Ka-Yiu

    2006-02-20

    Among the pharmacologically important terpenoid indole alkaloids produced by Catharanthus roseus are the anti-cancer drugs vinblastine and vincristine. These two drugs are produced in small yields within the plant, which makes them expensive to produce commercially. Metabolic engineering has focused on increasing flux through this pathway by various means such as elicitation, precursor feeding, and introduction of genes encoding specific metabolic enzymes into the plant. Recently in our lab, a feedback-resistant anthranilate synthase alpha subunit was over-expressed in C. roseus hairy roots under the control of a glucocorticoid inducible promoter system. Upon induction we observed a large increase in the indole precursors, tryptophan, and tryptamine. The current work explores the effects of over-expressing the anthranilate synthase alpha or alpha and beta subunits in combination with feeding with the terpenoid precursors 1-deoxy-D-xylulose, loganin, and secologanin. In feeding 1-deoxy-D-xylulose to the hairy root line expressing the anthranilate synthase alpha subunit, we observed an increase of 125% in hörhammericine levels in the induced samples, while loganin feeding increased catharanthine by 45% in the induced samples. Loganin feeding to the hairy root line expressing anthranilate synthase alpha and beta subunits increases catharanthine by 26%, ajmalicine by 84%, lochnericine by 119%, and tabersonine by 225% in the induced samples. These results suggest that the terpenoid precursors to the terpenoid indole alkaloids are important factors in terpenoid indole alkaloid production.

  16. The crystal structure of the complex of Zea mays alpha subunit with a fragment of human beta subunit provides the clue to the architecture of protein kinase CK2 holoenzyme

    DEFF Research Database (Denmark)

    Battistutta, R; Sarno, S; De Moliner, E

    2000-01-01

    The crystal structure of a complex between the catalytic alpha subunit of Zea mays CK2 and a 23-mer peptide corresponding the C-terminal sequence 181-203 of the human CK2 regulatory beta subunit has been determined at 3.16-A resolution. The complex, composed of two alpha chains and two peptides...

  17. Alternatively spliced forms of the Drosophila alphaPS2 subunit of integrin are sufficient for viability and can replace the function of the alphaPS1 subunit of integrin in the retina.

    Science.gov (United States)

    Roote, C E; Zusman, S

    1996-06-01

    The Drosophila inflated (if) gene encodes the alphaPS2 subunit of the PS family of integrins. The if transcript is spliced such that alphaPS2 is found in two alternative forms, alphaPS2(C) and alphaPS2(m8), which differ by 25 amino acid residues in a region shown to affect cation requirements and ligand specificity. In this study, we examine the functional significance of the protein isoforms of if by analyzing the ability of transgenes producing only one isoform to rescue developmental abnormalities associated with complete loss of PS2 integrin. We find that either form of alphaPS2 is sufficient to rescue if- animals to viability; however, the alphaPS2(C) form promotes higher survival of the organism. Furthermore, these studies suggest distinct roles for alphaPS2(C) and alphaPS2(m8) during development. When expressed in the developing wing, alphaPS2(m8) is more efficient at rescuing the if wing blister phenotype than is alphaPS2(C). Expression of alphaPS2(C) in the eye produces dominant disruption of photoreceptor organization. We have also examined the ability of alphaPS2 and alphaPS1 to maintain photoreceptor organization in the Drosophila retina. Clonal analysis of sectioned eyes suggests a requirement for alphaPS1, but not alphaPS2. However, ectopic expression of if(m8) or if(C) shows that either splice form Of alphaPS2 can functionally replace alphaPS1 and rescue the mew eye phenotype.

  18. The helical domain of a G protein alpha subunit is a regulator of its effector.

    Science.gov (United States)

    Liu, W; Northup, J K

    1998-10-27

    The alpha subunit (Galpha) of heterotrimeric G proteins is a major determinant of signaling selectivity. The Galpha structure essentially comprises a GTPase "Ras-like" domain (RasD) and a unique alpha-helical domain (HD). We used the vertebrate phototransduction model to test for potential functions of HD and found that the HD of the retinal transducin Galpha (Galphat) and the closely related gustducin (Galphag), but not Galphai1, Galphas, or Galphaq synergistically enhance guanosine 5'-gamma[-thio]triphosphate bound Galphat (GalphatGTPgammaS) activation of bovine rod cGMP phosphodiesterase (PDE). In addition, both HDt and HDg, but not HDi1, HDs, or HDq attenuate the trypsin-activated PDE. GalphatGDP and HDt attenuation of trypsin-activated PDE saturate with similar affinities and to an identical 38% of initial activity. These data suggest that interaction of intact Galphat with the PDE catalytic core may be caused by the HD moiety, and they indicate an independent site(s) for the HD moiety of Galphat within the PDE catalytic core in addition to the sites for the inhibitory Pgamma subunits. The HD moiety of GalphatGDP is an attenuator of the activated catalytic core, whereas in the presence of activated GalphatGTPgammaS the independently expressed HDt is a potent synergist. Rhodopsin catalysis of Galphat activation enhances the PDE activation produced by subsaturating levels of Galphat, suggesting a HD-moiety synergism from a transient conformation of Galphat. These results establish HD-selective regulations of vertebrate retinal PDE, and they provide evidence demonstrating that the HD is a modulatory domain. We suggest that the HD works in concert with the RasD, enhancing the efficiency of G protein signaling.

  19. Increased Expression of Laminin Subunit Alpha 1 Chain by dCas9-VP160

    Directory of Open Access Journals (Sweden)

    Arnaud Perrin

    2017-03-01

    Full Text Available Laminin-111 protein complex links the extracellular matrix to integrin α7β1 in sarcolemma, thus replacing in dystrophic muscles links normally insured by the dystrophin complex. Laminin-111 injection in mdx mouse stabilized sarcolemma, restored serum creatine kinase to wild-type levels, and protected muscles from exercised-induced damages. These results suggested that increased laminin-111 is a potential therapy for DMD. Laminin subunit beta 1 and laminin subunit gamma 1 are expressed in adult human muscle, but laminin subunit alpha 1 (LAMA1 gene is expressed only during embryogenesis. We thus developed an alternative method to laminin-111 protein repeated administration by inducing expression of the endogenous mouse Lama1 gene. This was done with the CRSPR/Cas9 system, i.e., by targeting the Lama1 promoter with one or several gRNAs and a dCas9 coupled with the VP160 transcription activation domain. Lama1 mRNA (qRT-PCR and proteins (immunohistochemistry and western blot were not detected in the control C2C12 myoblasts and in control muscles. However, significant expression was observed in cells transfected and in mouse muscles electroporated with plasmids coding for dCas9-VP160 and a gRNA. Larger synergic increases were observed by using two or three gRNAs. The increased Lama1 expression did not modify the expression of the α7 and β1 integrins. Increased expression of Lama1 by the CRISPR/Cas9 system will have to be further investigated by systemic delivery of the CRISPR/Cas9 components to verify whether this could be a treatment for several myopathies.

  20. Reduction and Methyl Transfer Kinetics of the Alpha Subunit from Acetyl-Coenzyme A Synthase

    Energy Technology Data Exchange (ETDEWEB)

    Xiangshi Tan; Christopher Sewell; Qingwu Yang; Paul A. Lindahl

    2003-01-15

    OAK-B135 Stopped-flow was used to evaluate the methylation and reduction kinetics of the isolated alpha subunit of acetyl-Coenzyme A synthase from Moorella thermoacetica. This catalytically active subunit contains a novel Ni-X-Fe4S4 cluster and a putative unidentified n =2 redox site called D. The D-site must be reduced for a methyl group to transfer from a corrinoid-iron-sulfur protein, a key step in the catalytic synthesis of acetyl-CoA. The Fe4S4 component of this cluster is also redox active, raising the possibility that it is the D-site or a portion thereof. Results presented demonstrate that the D-site reduces far faster than the Fe4S4 component, effectively eliminating this possibility. Rather, this component may alter catalytically important properties of the Ni center. The D-site is reduced through a pathway that probably does not involve the Fe4S4 component of this active-site cluster.

  1. NMR analysis of G-protein betagamma subunit complexes reveals a dynamic G(alpha)-Gbetagamma subunit interface and multiple protein recognition modes.

    Science.gov (United States)

    Smrcka, Alan V; Kichik, Nessim; Tarragó, Teresa; Burroughs, Michael; Park, Min-Sun; Itoga, Nathan K; Stern, Harry A; Willardson, Barry M; Giralt, Ernest

    2010-01-12

    G-protein betagamma (Gbetagamma) subunits interact with a wide range of molecular partners including: G(alpha) subunits, effectors, peptides, and small molecule inhibitors. The molecular mechanisms underlying the ability to accommodate this wide range of structurally distinct binding partners are not well understood. To uncover the role of protein flexibility and alterations in protein conformation in molecular recognition by Gbetagamma, a method for site-specific (15)N-labeling of Gbeta-Trp residue backbone and indole amines in insect cells was developed. Transverse Relaxation Optimized Spectroscopy-Heteronuclear Single-Quantum Coherence Nuclear Magnetic Resonance (TROSY-HSQC NMR) analysis of (15)N-Trp Gbetagamma identified well-dispersed signals for the individual Trp residue side chain and amide positions. Surprisingly, a wide range of signal intensities was observed in the spectrum, likely representing a range of backbone and side chain mobilities. The signal for GbetaW99 indole was very intense, suggesting a high level of mobility on the protein surface and molecular dynamics simulations indicate that GbetaW99 is highly mobile on the nanosecond timescale in comparison with other Gbeta tryptophans. Binding of peptides and phosducin dramatically altered the mobility of GbetaW99 and GbetaW332 in the binding site and the chemical shifts at sites distant from the direct binding surface in distinct ways. In contrast, binding of G(alpha)(i1)-GDP to Gbetagamma had relatively little effect on the spectrum and, most surprisingly, did not significantly alter Trp mobility at the subunit interface. This suggests the inactive heterotrimer in solution adopts a conformation with an open subunit interface a large percentage of the time. Overall, these data show that Gbetagamma subunits explore a range of conformations that can be exploited during molecular recognition by diverse binding partners.

  2. Identification of a common amino acid polymorphism in the p85alpha regulatory subunit of phosphatidylinositol 3-kinase

    DEFF Research Database (Denmark)

    Hansen, Torben; Andersen, C B; Echwald, Søren Morgenthaler

    1997-01-01

    in a phenotype study. Single-strand conformational polymorphism and heteroduplex analysis of the coding region of the regulatory p85alpha subunit in cDNA isolated from human muscle tissue from 70 insulin-resistant NIDDM patients and 12 control subjects revealed three silent polymorphisms and a missense mutation...

  3. GROWTH HORMONE-, ALPHA-SUBUNIT AND THYROTROPIN-COSECRETING PITUITARY-ADENOMA IN FAMILIAL SETTING OF PITUITARY-TUMOR

    NARCIS (Netherlands)

    LINKS, TP; MONKELBAAN, JF; DULLAART, RPF; VANHAEFTEN, TW

    1993-01-01

    A patient with acromegaly and hyperthyroidism due to a growth hormone-, thyrotrophin- and alpha-subunit-secreting pituitary adenoma is described. His deceased father had suffered from a pituitary tumour, and was likely to have had acromegaly as well. Plasma growth hormone and insulin-like growth fac

  4. Diverse functional consequences of mutations in the Na+/K+-ATPase alpha2-subunit causing familial hemiplegic migraine type 2.

    NARCIS (Netherlands)

    Tavraz, N.N.; Friedrich, T.; Durr, K.L.; Koenderink, J.B.; Bamberg, E.; Freilinger, T.; Dichgans, M.

    2008-01-01

    Mutations in ATP1A2, the gene coding for the Na(+)/K(+)-ATPase alpha(2)-subunit, are associated with both familial hemiplegic migraine and sporadic cases of hemiplegic migraine. In this study, we examined the functional properties of 11 ATP1A2 mutations associated with familial or sporadic hemiplegi

  5. Cloning, chromosomal localization, and functional expression of the alpha 1 subunit of the L-type voltage-dependent calcium channel from normal human heart

    NARCIS (Netherlands)

    Schultz, D; Mikala, G; Yatani, A; Engle, D B; Iles, D E; Segers, B; Sinke, R J; Weghuis, D O; Klöckner, U; Wakamori, M

    1993-01-01

    A unique structural variant of the cardiac L-type voltage-dependent calcium channel alpha 1 subunit cDNA was isolated from libraries derived from normal human heart mRNA. The deduced amino acid sequence shows significant homology to other calcium channel alpha 1 subunits. However, differences from t

  6. The crystal structure of the complex of Zea mays alpha subunit with a fragment of human beta subunit provides the clue to the architecture of protein kinase CK2 holoenzyme

    DEFF Research Database (Denmark)

    Battistutta, R; Sarno, S; De Moliner, E

    2000-01-01

    The crystal structure of a complex between the catalytic alpha subunit of Zea mays CK2 and a 23-mer peptide corresponding the C-terminal sequence 181-203 of the human CK2 regulatory beta subunit has been determined at 3.16-A resolution. The complex, composed of two alpha chains and two peptides......, presents a molecular twofold axis, with each peptide interacting with both alpha chains. In the derived model of the holoenzyme, the regulatory subunits are positioned on the opposite side with respect to the opening of the catalytic sites, that remain accessible to substrates and cosubstrates. The beta...... subunit can influence the catalytic activity both directly and by promoting the formation of the alpha2 dimer, in which each alpha chain interacts with the active site of the other. Furthermore, the two active sites are so close in space that they can simultaneously bind and phosphorylate two...

  7. Hyperkalemic periodic paralysis caused by recurring mutation in the adult muscle sodium channel alpha-subunit gene.

    Science.gov (United States)

    Sillén, A; Wadelius, C; Sundvall, M; Ahlsten, G; Gustavson, K H

    1996-01-01

    Linkage studies and mutation analysis were performed in two Swedish families with hyperkalemic periodic paralysis (HYPP), an autosomal dominant inherited disorder characterized by episodic muscle weakness associated with increasing or high levels of serum potassium. The gene for HYPP is the gene encoding the alpha-subunit of the sodium channel of adult human skeletal muscle (SCN4A). SCN4A has been localized on chromosome 17 q closely linked to the human growth hormone gene. Linkage between a microsatellite polymorphism in the SCN4A gene and the disease was shown in two Swedish families (Z = 12.10 theta = 0). Sequence analysis revealed that the two Swedish families have got a C to T transition at position 2188 in the cDNA. At the protein level this Thr 704 to Met mutation is located in the fifth membrane spanning segment of domain II of the protein, as previously described (28). The mutation was linked to different microsatellite alleles regarding both a (GT)n and a (GA)n repeat in the gene. Either the families are related and new mutations have occurred in both microsatellites when the pedigrees were separated or the mutation has arisen independently in the two families analysed. From the mutant alleles characterized so far it seems as if a limited number of mutations is present in this gene.

  8. Mutations in SCN9A, encoding a sodium channel alpha subunit, in patients with primary erythermalgia.

    Science.gov (United States)

    Yang, Y; Wang, Y; Li, S; Xu, Z; Li, H; Ma, L; Fan, J; Bu, D; Liu, B; Fan, Z; Wu, G; Jin, J; Ding, B; Zhu, X; Shen, Y

    2004-03-01

    Primary erythermalgia is a rare autosomal dominant disease characterised by intermittent burning pain with redness and heat in the extremities. A previous study established the linkage of primary erythermalgia to a 7.94 cM interval on chromosome 2q, but the causative gene was not identified. We performed linkage analysis in a Chinese family with primary erythermalgia, and screened the mutations in the two candidate genes, SCN9A and GCA, in the family and a sporadic patient. Linkage analysis yielded a maximum lod score of 2.11 for both markers D2S2370 and D2S2330. Based on critical recombination events in two patients in the family, we further limited the genetic region to 5.98 cM between D2S2370 and D2S2345. We then identified two missense mutations in SCN9A in the family (T2573A) and the sporadic patient (T2543C). Our data suggest that mutations in SCN9A cause primary erythermalgia. SCN9A, encoding a voltage-gated sodium channel alpha subunit predominantly expressed in sensory and sympathetic neurones, may play an important role in nociception and vasomotor regulation.

  9. Differential expression of G protein alpha and ß subunit genes during development of Phytophthora infestans

    NARCIS (Netherlands)

    Laxalt, A.M.; Latijnhouwers, M.; Hulten, van M.; Govers, F.

    2002-01-01

    A G protein subunit gene (pigpa1) and a G protein subunit gene (pigpb1) were isolated from the oomycete Phytophthora infestans, the causal agent of potato late blight. Heterotrimeric G proteins are evolutionary conserved GTP-binding proteins that are composed of ,, and subunits and participate in di

  10. Activity of nAChRs containing alpha9 subunits modulates synapse stabilization via bidirectional signaling programs.

    Science.gov (United States)

    Murthy, Vidya; Taranda, Julián; Elgoyhen, A Belén; Vetter, Douglas E

    2009-12-01

    Although the synaptogenic program for cholinergic synapses of the neuromuscular junction is well known, little is known of the identity or dynamic expression patterns of proteins involved in non-neuromuscular nicotinic synapse development. We have previously demonstrated abnormal presynaptic terminal morphology following loss of nicotinic acetylcholine receptor (nAChR) alpha9 subunit expression in adult cochleae. However, the molecular mechanisms underlying these changes have remained obscure. To better understand synapse formation and the role of cholinergic activity in the synaptogenesis of the inner ear, we exploit the nAChR alpha9 subunit null mouse. In this mouse, functional acetylcholine (ACh) neurotransmission to the hair cells is completely silenced. Results demonstrate a premature, effusive innervation to the synaptic pole of the outer hair cells in alpha9 null mice coinciding with delayed expression of cell adhesion proteins during the period of effusive contact. Collapse of the ectopic innervation coincides with an age-related hyperexpression pattern in the null mice. In addition, we document changes in expression of presynaptic vesicle recycling/trafficking machinery in the alpha9 null mice that suggests a bidirectional information flow between the target of the neural innervation (the hair cells) and the presynaptic terminal that is modified by hair cell nAChR activity. Loss of nAChR activity may alter transcriptional activity, as CREB binding protein expression is decreased coincident with the increased expression of N-Cadherin in the adult alpha9 null mice. Finally, by using mice expressing the nondesensitizing alpha9 L9'T point mutant nAChR subunit, we show that increased nAChR activity drives synaptic hyperinnervation.

  11. Genetic analysis of the Drosophila alphaPS2 integrin subunit reveals discrete adhesive, morphogenetic and sarcomeric functions.

    Science.gov (United States)

    Bloor, J W; Brown, N H

    1998-03-01

    The integrin family of cell surface receptors mediates cell-substrate and cell-to-cell adhesion and transmits intracellular signals. In Drosophila there is good evidence for an adhesive role of integrins, but evidence for integrin signalling has remained elusive. Each integrin is an alphabeta heterodimer, and the Drosophila betaPS subunit forms at least two integrins by association with different alpha subunits: alphaPS1betaPS (PS1) and alphaPS2betaPS (PS2). The complex pattern of PS2 integrin expression includes, but is more extensive than, the sites where PS2 has a known requirement. In order to investigate whether PS2 integrin is required at these additional sites and/or has functions besides mediating adhesion, a comprehensive genetic analysis of inflated, the gene that encodes alphaPS2, was performed. We isolated 35 new inflated alleles, and obtained 10 alleles from our colleagues. The majority of alleles are amorphs (36/45) or hypomorphs (4/45), but five alleles that affect specific developmental processes were identified. Interallelic complementation between these alleles suggests that some may affect distinct functional domains of the alphaPS2 protein, which specify particular interactions that promote adhesion or signalling. One new allele reveals that the PS2 integrin is required for the development of the adult halteres and legs as well as the wing.

  12. Subunit II of Bacillus subtilis cytochrome c oxidase is a lipoprotein

    NARCIS (Netherlands)

    Bengtsson, J; Tjalsma, H; Rivolta, C; Hederstedt, L

    1999-01-01

    The sequence of the N-terminal end of the deduced ctaC gene product of Bacillus species has the features of a bacterial lipoprotein. CtaC is the subunit II of cytochrome caa(3), which is a cytochrome c oxidase. Using Bacillus subtilis mutants blocked in lipoprotein synthesis, we show that CtaC is a

  13. Uniparental disomy of chromosome 2 resulting in lethal trifunctional protein deficiency due to homozygous alpha-subunit mutations.

    Science.gov (United States)

    Spiekerkoetter, Ute; Eeds, Angela; Yue, Zou; Haines, Jonathan; Strauss, Arnold W; Summar, Marshall

    2002-12-01

    The mitochondrial trifunctional protein (TFP) is an enzyme complex of the fatty acid beta-oxidation cycle composed of an alpha- and a beta-subunit. The two encoding genes are located in the same region on chromosome 2 (2p23). TFP deficiency due to either alpha- or beta-subunit mutations is characterized by mutational and phenotypic heterogeneity with severe, early-onset, cardiac forms and milder, later-onset, myopathic phenotypes. In two unrelated patients with lethal TFP deficiency, we delineated apparently homozygous alpha-subunit mutations that were present in heterozygous form in both mothers, but not in either biological father. We performed a microsatellite repeat analysis of both patients and their parents using seven chromosome 2-specific polymorphic DNA markers and four nonchromosome 2 markers. In both patients, two chromosome 2-specific markers demonstrated maternal isodisomy of chromosome 2. The other five chromosome 2-specific markers were noninformative in each patient. Inheritance of alleles from chromosomes 4, 5, and 7 was consistent with paternity. These results explain the apparently anomalous pattern of transmission. Six of our 12 known TFP-deficient patients with alpha-subunit mutations have disease due to homozygous changes and two of them via the mechanism of uniparental disomy (UPD) (16.7%). For very rare autosomal recessive diseases, UPD may represent a common mechanism. This study emphasizes the need to confirm mutations in parents whenever possible. TFP deficiency is another disorder that has become manifest due to isodisomy of chromosome 2. This information will impact genetic counseling for these families, reducing greatly the 25% risk normally used for recessive disorders.

  14. Increased sensitivity of the neuronal nicotinic receptor alpha 2 subunit causes familial epilepsy with nocturnal wandering and ictal fear.

    Science.gov (United States)

    Aridon, Paolo; Marini, Carla; Di Resta, Chiara; Brilli, Elisa; De Fusco, Maurizio; Politi, Fausta; Parrini, Elena; Manfredi, Irene; Pisano, Tiziana; Pruna, Dario; Curia, Giulia; Cianchetti, Carlo; Pasqualetti, Massimo; Becchetti, Andrea; Guerrini, Renzo; Casari, Giorgio

    2006-08-01

    Sleep has traditionally been recognized as a precipitating factor for some forms of epilepsy, although differential diagnosis between some seizure types and parasomnias may be difficult. Autosomal dominant frontal lobe epilepsy is characterized by nocturnal seizures with hyperkinetic automatisms and poorly organized stereotyped movements and has been associated with mutations of the alpha 4 and beta 2 subunits of the neuronal nicotinic acetylcholine receptor. We performed a clinical and molecular genetic study of a large pedigree segregating sleep-related epilepsy in which seizures are associated with fear sensation, tongue movements, and nocturnal wandering, closely resembling nightmares and sleep walking. We identified a new genetic locus for familial sleep-related focal epilepsy on chromosome 8p12.3-8q12.3. By sequencing the positional candidate neuronal cholinergic receptor alpha 2 subunit gene (CHRNA2), we detected a heterozygous missense mutation, I279N, in the first transmembrane domain that is crucial for receptor function. Whole-cell recordings of transiently transfected HEK293 cells expressing either the mutant or the wild-type receptor showed that the new CHRNA2 mutation markedly increases the receptor sensitivity to acetylcholine, therefore indicating that the nicotinic alpha 2 subunit alteration is the underlying cause. CHRNA2 is the third neuronal cholinergic receptor gene to be associated with familial sleep-related epilepsies. Compared with the CHRNA4 and CHRNB2 mutations reported elsewhere, CHRNA2 mutations cause a more complex and finalized ictal behavior.

  15. Canine chondrodysplasia caused by a truncating mutation in collagen-binding integrin alpha subunit 10.

    Directory of Open Access Journals (Sweden)

    Kaisa Kyöstilä

    Full Text Available The skeletal dysplasias are disorders of the bone and cartilage tissues. Similarly to humans, several dog breeds have been reported to suffer from different types of genetic skeletal disorders. We have studied the molecular genetic background of an autosomal recessive chondrodysplasia that affects the Norwegian Elkhound and Karelian Bear Dog breeds. The affected dogs suffer from disproportionate short stature dwarfism of varying severity. Through a genome-wide approach, we mapped the chondrodysplasia locus to a 2-Mb region on canine chromosome 17 in nine affected and nine healthy Elkhounds (praw = 7.42×10(-6, pgenome-wide = 0.013. The associated locus contained a promising candidate gene, cartilage specific integrin alpha 10 (ITGA10, and mutation screening of its 30 exons revealed a nonsense mutation in exon 16 (c.2083C>T; p.Arg695* that segregated fully with the disease in both breeds (p = 2.5×10(-23. A 24% mutation carrier frequency was indicated in NEs and an 8% frequency in KBDs. The ITGA10 gene product, integrin receptor α10-subunit combines into a collagen-binding α10β1 integrin receptor, which is expressed in cartilage chondrocytes and mediates chondrocyte-matrix interactions during endochondral ossification. As a consequence of the nonsense mutation, the α10-protein was not detected in the affected cartilage tissue. The canine phenotype highlights the importance of the α10β1 integrin in bone growth, and the large animal model could be utilized to further delineate its specific functions. Finally, this study revealed a candidate gene for human chondrodysplasias and enabled the development of a genetic test for breeding purposes to eradicate the disease from the two dog breeds.

  16. Interaction of retinal guanylate cyclase with the alpha subunit of transducin: potential role in transducin localization.

    Science.gov (United States)

    Rosenzweig, Derek H; Nair, K Saidas; Levay, Konstantin; Peshenko, Igor V; Crabb, John W; Dizhoor, Alexander M; Slepak, Vladlen Z

    2009-02-01

    Vertebrate phototransduction is mediated by cGMP, which is generated by retGC (retinal guanylate cyclase) and degraded by cGMP phosphodiesterase. Light stimulates cGMP hydrolysis via the G-protein transducin, which directly binds to and activates phosphodiesterase. Bright light also causes relocalization of transducin from the OS (outer segments) of the rod cells to the inner compartments. In the present study, we show experimental evidence for a previously unknown interaction between G(alphat) (the transducin alpha subunit) and retGC. G(alphat) co-immunoprecipitates with retGC from the retina or from co-transfected COS-7 cells. The retGC-G(alphat) complex is also present in cones. The interaction also occurs in mice lacking RGS9 (regulator of G-protein signalling 9), a protein previously shown to associate with both G(alphat) and retGC. The G(alphat)-retGC interaction is mediated primarily by the kinase homology domain of retGC, which binds GDP-bound G(alphat) stronger than the GTP[S] (GTPgammaS; guanosine 5'-[gamma-thio]triphosphate) form. Neither G(alphat) nor G(betagamma) affect retGC-mediated cGMP synthesis, regardless of the presence of GCAP (guanylate cyclase activating protein) and Ca2+. The rate of light-dependent transducin redistribution from the OS to the inner segments is markedly accelerated in the retGC-1-knockout mice, while the migration of transducin to the OS after the onset of darkness is delayed. Supplementation of permeabilized photoreceptors with cGMP does not affect transducin translocation. Taken together, these results suggest that the protein-protein interaction between G(alphat) and retGC represents a novel mechanism regulating light-dependent translocation of transducin in rod photoreceptors.

  17. Spectral and Temporal Properties of the Alpha and Beta Subunits and (alpha Beta) Monomer Isolated from Nostoc SP. Using Picosecond Laser Spectroscopy.

    Science.gov (United States)

    Dagen, Aaron J.

    1985-12-01

    The fluorescence decay profiles, relative quantum yield and transmission of the (alpha), (beta) and ((alpha)(beta)) complexes from phycoerythrin isolated from the photosynthetic antenna system of Nostoc sp. and measured by single picosecond laser spectroscopic techniques is studied. The fluorescence decay profiles of all three complexes are found to be intensity independent for the intensity range investigated ((TURN)4 x 10('13) to (TURN)4 x 10('15) photons-cm('-2) per pulse). The apparent decrease in the relative quantum yield of all three complexes as intensity increases is offset by a corresponding increase in the relative transmission. This evidence, along with the intensity independent fluorescence kinetics, suggests that exciton annihilation is absent in these complexes. The decay profiles are fit to models assuming energy transfer amongst fluorescing chromophores. The intraprotein transfer rate is found to be 100 ps in the (alpha) subunit, 666 ps in the (beta) subunit. Constraining these rates to be identical in the monomer results in explaining the monomer kinetics by an increase in the nonradiative rate of the f(,(beta)) chromophore, an apparent result of aggregation effects.

  18. Reconstitution of F1-ATPase activity from Escherichia coli subunits alpha, beta and subunit gamma tagged with six histidine residues at the C-terminus.

    Science.gov (United States)

    Ekuni, A; Watanabe, H; Kuroda, N; Sawada, K; Murakami, H; Kanazawa, H

    1998-05-01

    An engineered gamma subunit of Escherichia coli F1-ATPase with extra 14 and 20 amino acid residues at the N- and C-termini (His-tag gamma), respectively, was overproduced in E. coli and purified. Six histidines are included in the C-terminal extension. The reconstituted F1 containing alpha, beta, and His-tagged gamma exhibited sixty percent of the wild-type ATPase activity. The reconstituted alphabeta His-tag gamma complex was subjected to affinity chromatography with nickel-nitrilotriacetic acid (Ni-NTA) agarose resin. ATPase activity was eluted specifically with imidazole. These results implied that the tag sequence protruded to the surface of the complex and did not seriously impair the activity. The reconstituted alphabeta His-tag gamma complex, even after its binding to the resin, exhibited ATPase activity suggesting that the gamma subunit, when fixed to a solid phase, may rotate the alphabeta complex. This system may provide a new approach for analysis of the rotation mechanisms in F1-ATPase.

  19. Ab initio study of the {sup 57}Fe quadrupole splitting in the heme models of {alpha}- and {beta}-subunits in tetrameric deoxyhemoglobin

    Energy Technology Data Exchange (ETDEWEB)

    Yuryeva, E. I. [Ural Branch of the Russian Academy of Sciences, Institute of Solid State Chemistry (Russian Federation); Oshtrakh, M. I., E-mail: oshtrakh@mail.utnet.ru [Ural State Technical University - UPI, Division of Applied Biophysics, Faculty of Physical Techniques and Devices for Quality Control (Russian Federation)

    2005-09-15

    Ab initio X{alpha} discrete variation method was used for calculation of quadrupole splitting for the rough heme models in {alpha}- and {beta}-subunits of tetrameric deoxyhemoglobin accounting small stereochemical variations. The differences of theoretical values of quadrupole splitting for these heme models were obtained.

  20. The C-terminal domain of human grp94 protects the catalytic subunit of protein kinase CK2 (CK2alpha) against thermal aggregation. Role of disulfide bonds

    DEFF Research Database (Denmark)

    Roher, N; Miró, F; Boldyreff, B

    2001-01-01

    with dithiothreitol. Grp94-CT conferred protection against aggregation on the catalytic subunit of protein kinase CK2 (CK2alpha), although it did not protect against thermal inactivation. This anti-aggregation effect of grp94-CT was concentration dependent, with full protection achieved at grp94-CT/CK2alpha molar...

  1. Improving Saccharomyces cerevisiae ethanol production and tolerance via RNA polymerase II subunit Rpb7.

    Science.gov (United States)

    Qiu, Zilong; Jiang, Rongrong

    2017-01-01

    Classical strain engineering methods often have limitations in altering multigenetic cellular phenotypes. Here we try to improve Saccharomyces cerevisiae ethanol tolerance and productivity by reprogramming its transcription profile through rewiring its key transcription component RNA polymerase II (RNAP II), which plays a central role in synthesizing mRNAs. This is the first report on using directed evolution method to engineer RNAP II to alter S. cerevisiae strain phenotypes. Error-prone PCR was employed to engineer the subunit Rpb7 of RNAP II to improve yeast ethanol tolerance and production. Based on previous studies and the presumption that improved ethanol resistance would lead to enhanced ethanol production, we first isolated variant M1 with much improved resistance towards 8 and 10% ethanol. The ethanol titers of M1 was ~122 g/L (96.58% of the theoretical yield) under laboratory very high gravity (VHG) fermentation, 40% increase as compared to the control. DNA microarray assay showed that 369 genes had differential expression in M1 after 12 h VHG fermentation, which are involved in glycolysis, alcoholic fermentation, oxidative stress response, etc. This is the first study to demonstrate the possibility of engineering eukaryotic RNAP to alter global transcription profile and improve strain phenotypes. Targeting subunit Rpb7 of RNAP II was able to bring differential expression in hundreds of genes in S. cerevisiae, which finally led to improvement in yeast ethanol tolerance and production.

  2. TNF-alpha stimulation increases dental pulp stem cell migration in vitro through integrin alpha-6 subunit upregulation.

    Science.gov (United States)

    Shi, Lei; Fu, Shanqi; Fahim, Sidra; Pan, Shuang; Lina, He; Mu, Xiaodan; Niu, Yumei

    2017-03-01

    The dissemination of stem cells into tissues requiring inflammatory and reparative response is fundamentally dependent upon their chemotactic migration. Expression of TNF-α is up regulated in inflamed pulps. Dental pulp cells are also known to express integrin α6 subunit. Expression of integrin subunit α6 has been linked to the acquisition of migratory potential in a wide variety of cell types in both pathological and physiological capacities. Therefore, in this study we examined the effects of a pleiotropic cytokine TNF-α on the migration of hDPSCs and investigated its relationship with expression of integrin α6 in hDPSCs during chemotactic migration. hDPSC cultures were established. Protein expression profile of α6 integrin subunit was determined. Effect of exogenous TNF-α (50ng/mL) on hDPSCs' migration potential was evaluated by transwell inserts and in vitro scratch assay. Upregulation/downregulation of TNF-α mediated migration was assayed in presence/absence of integrin α6 respectively. To suppress integrin α6 expression, cells were transfected with integrin α6 siRNA and then cell migration and cytoskeletal changes were evaluated. Our results showed significant increase of hDPSCs' migration after stimulation with TNF-α. By knockdown of integrin α6, which is upregulated by TNF-α, we observed a decrease in the TNF-α directed chemotaxis of hDPSCs. In this study, we show that activation of integrin α6 brought about by TNF-α led to an increase in migratory activity in DPSCs in vitro thus describing a novel association between a cytokine TNF-α and α6 chain of an adhesion receptor integrin in regulating migration of hDPSCs. Copyright © 2016. Published by Elsevier Ltd.

  3. Expression and characterization of a recombinant maize CK-2 alpha subunit

    DEFF Research Database (Denmark)

    Boldyreff, B; Meggio, F; Dobrowolska, G

    1993-01-01

    to support the immunological data also by biochemical and biophysical experiments the availability of a recombinant CK-2 alpha from maize was a prerequisite. A maize cDNA clone of maize CK-2 alpha was expressed in the bacterial strain BL21 (DE3). The recombinant protein was purified to homogeneity; its...... molecular mass on one-dimensional SDS PAGE was estimated to be 36.5 kDa. The calculated molecular mass according to the amino acid composition is 39,228 Da (332 amino acids). The recombinant maize CK-2 alpha (rmCK-2 alpha) exhibited mostly the same properties as the recombinant human CK-2 alpha (rhCK-2...

  4. The cardiac alpha(1C) subunit can support excitation-triggered Ca2+ entry in dysgenic and dyspedic myotubes.

    Science.gov (United States)

    Bannister, Roger A; Beam, Kurt G

    2009-01-01

    Depolarization-induced entry of divalent ions into skeletal muscle has been attributed to a process termed Excitation-Coupled Ca(2+) Entry (ECCE), which is hypothesized to require the interaction of the ryanodine receptor (RyR1), the L-type Ca(2+) channel (DHPR) and another unidentified cation channel. Thus, ECCE is absent in myotubes lacking either the DHPR (dysgenic) or RyR1 (dyspedic). Furthermore, ECCE, as measured by Mn(2+) quench of Fura-2, is reconstituted by expression of a mutant DHPR alpha(1S) subunit (SkEIIIK) thought to be impermeable to divalent cations. Previously, we showed that the bulk of depolarization-induced Ca(2+) entry could be explained by the skeletal L-type current. Accordingly, one would predict that any Ca(2+) current similar to the endogenous current would restore such entry and that this entry would not require coupling to either the DHPR or RyR1. Here, we show that expression of the cardiac alpha(1C) subunit in either dysgenic or dyspedic myotubes does result in Ca(2+) entry similar to that ascribed to ECCE. We also demonstrate that, when potentiated by strong depolarization and Bay K 8644, SkEIIIK supports entry of Mn(2+). These results strongly support the idea that the L-type channel is the major route of Ca(2+) entry in response to repetitive or prolonged depolarization of skeletal muscle.

  5. A network of stimulatory and inhibitory G alpha-subunits regulates olfaction in Caenorhabditis elegans.

    NARCIS (Netherlands)

    H. Lans (Hannes); S. Rademakers (Suzanne); G. Jansen (Gert)

    2004-01-01

    textabstractThe two pairs of sensory neurons of C. elegans, AWA and AWC, that mediate odorant attraction, express six Galpha-subunits, suggesting that olfaction is regulated by a complex signaling network. Here, we describe the cellular localization and functions of the six olfacto

  6. Molecular determinants of desensitization and assembly of the chimeric GABA(A) receptor subunits (alpha1/gamma2) and (gamma2/alpha1) in combinations with beta2 and gamma2

    DEFF Research Database (Denmark)

    Elster, L; Kristiansen, U; Pickering, D S

    2001-01-01

    2 and the remainder of the gamma2 or alpha1 subunits, respectively, were expressed with beta2 and beta2gamma2 in Spodoptera frugiperda (Sf-9) cells using the baculovirus expression system. The (alpha1/gamma2)beta2 and (alpha1/gamma2)beta2gamma2 but not the (gamma2/alpha1)beta2 and (gamma2/alpha1......)beta2gamma2 subunit combinations formed functional receptor complexes as shown by whole-cell patch-clamp recordings and [3H]muscimol and [3H]flunitrazepam binding. Moreover, the surface immunofluorescence staining of Sf-9 cells expressing the (alpha1/gamma2)-containing receptors was pronounced...

  7. The catalytic subunit of protein phosphatase 1 gamma regulates thrombin-induced murine platelet alpha(IIbbeta(3 function.

    Directory of Open Access Journals (Sweden)

    Francisca C Gushiken

    Full Text Available Hemostasis and thrombosis are regulated by agonist-induced activation of platelet integrin alpha(IIbbeta(3. Integrin activation, in turn is mediated by cellular signaling via protein kinases and protein phosphatases. Although the catalytic subunit of protein phosphatase 1 (PP1c interacts with alpha(IIbbeta(3, the role of PP1c in platelet reactivity is unclear.Using gamma isoform of PP1c deficient mice (PP1cgamma(-/-, we show that the platelets have moderately decreased soluble fibrinogen binding and aggregation to low concentrations of thrombin or protease-activated receptor 4 (PAR4-activating peptide but not to adenosine diphosphate (ADP, collagen or collagen-related peptide (CRP. Thrombin-stimulated PP1cgamma(-/- platelets showed decreased alpha(IIbbeta(3 activation despite comparable levels of alpha(IIbbeta(3, PAR3, PAR4 expression and normal granule secretion. Functions regulated by outside-in integrin alpha(IIbbeta(3 signaling like adhesion to immobilized fibrinogen and clot retraction were not altered in PP1cgamma(-/- platelets. Thrombus formation induced by a light/dye injury in the cremaster muscle venules was significantly delayed in PP1cgamma(-/- mice. Phosphorylation of glycogen synthase kinase (GSK3beta-serine 9 that promotes platelet function, was reduced in thrombin-stimulated PP1cgamma(-/- platelets by an AKT independent mechanism. Inhibition of GSK3beta partially abolished the difference in fibrinogen binding between thrombin-stimulated wild type and PP1cgamma(-/- platelets.These studies illustrate a role for PP1cgamma in maintaining GSK3beta-serine9 phosphorylation downstream of thrombin signaling and promoting thrombus formation via fibrinogen binding and platelet aggregation.

  8. Cloning and characterization of genes encoding alpha and beta subunits of glutamate-gated chloride channel protein in Cylicocyclus nassatus.

    Science.gov (United States)

    Tandon, Ritesh; LePage, Keith T; Kaplan, Ray M

    2006-11-01

    The invertebrate glutamate-gated chloride channels (GluCls) are receptor molecules and targets for the avermectin-milbemycin (AM) group of anthelmintics. Mutations in GluCls are associated with ivermectin resistance in the soil dwelling nematode Caenorhabditis elegans and the parasitic nematode Cooperia oncophora. In this study, full-length cDNAs encoding alpha and beta subunits of GluCl were cloned and sequenced in Cylicocyclus nassatus, a common and important cyathostomin nematode parasite of horses. Both genes possess the sequence characteristics typical of GluCls, and phylogenetic analysis confirms that these genes are evolutionarily closely related to GluCls of other nematodes and flies. Complete coding sequences of C. nassatus GluCl-alpha and GluCl-beta were subcloned into pTL1 mammalian expression vector, and proteins were expressed in COS-7 cells. Ivermectin-binding characteristics were determined by incubating COS-7 cell membranes expressing C. nassatus GluCl-alpha and GluCl-beta proteins with [(3)H]ivermectin. In competitive binding experiments, fitting the data to a one site competition model, C. nassatus GluCl-alpha was found to bind [(3)H]ivermectin with a high amount of displaceable binding (IC(50)=208 pM). Compared to the mock-transfected COS-7 cells, the means of [(3)H]ivermectin binding were significantly different for C. nassatus GluCl-alpha and the Haemonchus contortus GluCl (HcGluCla) (p=0.018 and 0.023, respectively) but not for C. nassatus GluCl-beta (p=0.370). This is the first report of orthologs of GluCl genes and in vitro expression of an ivermectin-binding protein in a cyathostomin species. These data suggest the likelihood of a similar mechanism of action of AM drugs in these parasites, and suggest that mechanisms of resistance may also be similar.

  9. Conformational alterations resulting from mutations in cytoplasmic domains of the alpha subunit of the Na,K-ATPase

    DEFF Research Database (Denmark)

    Blostein, R; Daly, S E; MacAulay, Nanna;

    1998-01-01

    , and decreased sensitivity to inhibition by vanadate. The striking changes observed with alpha 1M32E233K suggests interactions between the N-terminus, the beta-strand in the M2-M3 loop and the catalytic phosphorylation site. The behavior of these mutants contrasts with that of least one mutant involving......This paper summarizes experiments concerned with the functional consequences of mutations in cytoplasmic regions of the alpha 1 subunit of the Na,K-ATPase, in particular the amino terminus, the first cytoplasmic loop between transmembrane segments M2 and M3, and the major cytoplasmic loop between M......4 and M5. In the first mutation (alpha 1M32), 32 residues were removed from the N-terminus. The second mutation (E233K) was in the putative beta strand of M2-M3 loop and the third, comprised the replacement of the amino terminal half of loop M4-M5 of the Na,K-ATPase with the homologous segment...

  10. Structural organization, sequence, and expression of the mouse HEXA gene encoding the alpha subunit of hexosaminidase A.

    Science.gov (United States)

    Wakamatsu, N; Benoit, G; Lamhonwah, A M; Zhang, Z X; Trasler, J M; Triggs-Raine, B L; Gravel, R A

    1994-11-01

    Genomic clones of the mouse HEXA gene encoding the alpha subunit of lysosomal beta-hexosaminidase A have been isolated, analyzed, and sequenced. The HEXA gene spans approximately 26 kb and consists of 14 exons and 13 introns. The 5' flanking region of the gene has three candidate GC boxes and a number of potential promoter and regulatory elements. Promoter analysis using deletion constructs of 5' flanking sequence fused to the bacterial chloramphenicol acetyltransferase (CAT) gene showed that 150 bp of 5' sequence was sufficient for expression in transfected monkey kidney COS cells. Determination of the sequence of the 5' end of the Hex alpha mRNA by an "anchor-ligation PCR" procedure showed that transcription is initiated from a cluster of sites centered -42, -32, and -21 bp from the first in-frame ATG. Northern blot analysis from 11 different tissues showed over five times the steady-state level of Hex alpha mRNA in testis as compared to that found in three different brain regions; the lowest level (about 1/3 of brain) was found in liver. Comparison of the 5' flanking sequence with that of the human HEXA gene revealed 78% identity within the first 100 bp. These data suggest that the mouse HEXA gene is controlled mainly by sequences located within 150 bp of the 5' flanking region, and we speculate that it may have a role, not only in brain and other tissues, but also in reproductive function in the adult male mouse.

  11. Estrogen dissociates Tau and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor subunit in postischemic hippocampus.

    Science.gov (United States)

    Cardona-Gómez, Gloria Patricia; Arango-Davila, Cesar; Gallego-Gómez, Juan Carlos; Barrera-Ocampo, Alvaro; Pimienta, Hernan; Garcia-Segura, Luis Miguel

    2006-08-21

    During cerebral ischemia, part of the damage associated with the hyperactivation of glutamate receptors results from the hyperphosphorylation of the microtubule-associated protein Tau. Previous studies have shown that estradiol treatment reduces neural damage after cerebral ischemia. Here, we show that transient occlusion of the middle cerebral artery results in the hyperphosphorylation of Tau and in a significant increase in the association of Tau with glycogen synthase kinase-3beta and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid type glutamate receptor subunits 2/3 in the hippocampus. Estradiol treatment decreased hippocampal injury, inhibited glycogen synthase kinase-3beta and decreased the hyperphosphorylation of Tau and the interaction of Tau with glycogen synthase kinase-3beta and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor. These findings suggest that ischemia produces a strong association between Tau and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor, and estradiol can exert at least part of its neuroprotective activity through inhibition of glycogen synthase kinase-3beta.

  12. Production and characterization of antibody probes directed at constant regions of the alpha and beta subunit of the human T cell receptor.

    Science.gov (United States)

    Fabbi, M; Acuto, O; Bensussan, A; Poole, C B; Reinherz, E L

    1985-08-01

    To generate antibodies directed at constant regions of the human T cell receptor, purified alpha and beta subunits of a human T cell antigen/major histocompatibility complex receptor from the REX tumor (Ti-REX) were isolated by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis and utilized to immunize rabbits. H36 (anti-alpha subunit) and H38 (anti-beta subunit) antisera were strongly reactive with the denatured subunits and also immunoprecipitated the Ti heterodimer from 125I surface-labeled lysates of REX, inducer, suppressor and cytotoxic T cell clones, peripheral T lymphocytes and thymocytes. Moreover, immunodepletion experiments showed that such antisera recognized antigenic determinant(s) shared by all Ti molecules expressed in the thymus. Several observations were made with these anticonstant region antibodies. First, peptide map analysis showed that the T cell receptor molecules recognized by the anti-clonotype and the anti-constant region heteroantisera on a given T cell clone are identical, thus supporting the view that the T cell receptor undergoes allelic exclusion. Second, since the individual antisera were weakly cross-reactive with the other denatured subunit, such subunits probably share conserved sequences. Third, the absence of antisera reactivity with intact cells implies that most of these constant region epitopes must be obscured by associated molecules, perhaps including one or more of the 20-25-kDa T3 subunits. Fourth, the extensive difference in two-dimensional peptide maps of Ti alpha subunits from clones of differing specificities makes it likely that the subunit contributes in a major way to antigen/major histocompatibility complex binding.

  13. A human RNA polymerase II subunit is encoded by a recently generated multigene family

    Directory of Open Access Journals (Sweden)

    Mattei Marie-Geneviève

    2001-11-01

    Full Text Available Abstract Background The sequences encoding the yeast RNA polymerase II (RPB subunits are single copy genes. Results While those characterized so far for the human (h RPB are also unique, we show that hRPB subunit 11 (hRPB11 is encoded by a multigene family, mapping on chromosome 7 at loci p12, q11.23 and q22. We focused on two members of this family, hRPB11a and hRPB11b: the first encodes subunit hRPB11a, which represents the major RPB11 component of the mammalian RPB complex ; the second generates polypeptides hRPB11bα and hRPB11bβ through differential splicing of its transcript and shares homologies with components of the hPMS2L multigene family related to genes involved in mismatch-repair functions (MMR. Both hRPB11a and b genes are transcribed in all human tissues tested. Using an inter-species complementation assay, we show that only hRPB11bα is functional in yeast. In marked contrast, we found that the unique murine homolog of RPB11 gene maps on chromosome 5 (band G, and encodes a single polypeptide which is identical to subunit hRPB11a. Conclusions The type hRPB11b gene appears to result from recent genomic recombination events in the evolution of primates, involving sequence elements related to the MMR apparatus.

  14. The Sleep–Wake Cycle in the Nicotinic Alpha-9 Acetylcholine Receptor Subunit Knock-Out Mice

    Directory of Open Access Journals (Sweden)

    Natalia Madrid-López

    2017-10-01

    Full Text Available There is a neural matrix controlling the sleep–wake cycle (SWC embedded within high ranking integrative mechanisms in the central nervous system. Nicotinic alpha-9 acetylcholine receptor subunit (alpha-9 nAChR participate in physiological processes occurring in sensory, endocrine and immune systems. There is a relationship between the SWC architecture, body homeostasis and sensory afferents so that disruption of afferent signaling is expected to affect the temporal organization of sleep and wake states. The analysis of the SWC of 9 nAChR knock-out animals may help to reveal the contribution of alpha-9 nAChR to sleep chronobiological determinants. Here we explore the polysomnogram in chronically implanted alpha-9 nAChR knock-out (KO and wild-type (WT individuals of the hybrid CBA/Sv129 mouse strain. Records were obtained in isolation chambers under a stable 12:12 light:dark cycle (LD. To unmask the 24-h modulation of the SWC a skeleton photoperiod (SP protocol was performed. Under LD the daily quota (in % of wakefulness (W, NREM sleep and REM sleep obtained in KO and WT animals were 45, 48 and 7, and 46, 46 and 8 respectively. Both groups exhibit nocturnal phase preference of W as well as diurnal and unimodal phase preference of NREM and REM sleep. The acrophase mean angles of KO vs. WT genotypes were not different (Zeitgeber Time: 6.5 vs. 14.9 for W, 4.3 vs. 2.8 for NREM sleep and 5.3 vs. 3.4 for REM sleep, respectively. Transference to SP do not affect daily state quotas, phase preferences and acrophases among genotypes. Unmasking phenomena of the SWC such as wake increment during the rest phase under SP was evident only among WT mice suggesting the involvement of retinal structures containing alpha-9 nAChR in masking processes. Furthermore, KO animals exhibit longer NREM and REM sleep episodes that is independent of illumination conditions. Consolidated diurnal NREM sleep contributed to obtain higher values of NREM sleep delta-EEG activity

  15. Effect of NIP-142 on potassium channel alpha-subunits Kv1.5, Kv4.2 and Kv4.3, and mouse atrial repolarization.

    Science.gov (United States)

    Tanaka, Hikaru; Namekata, Iyuki; Hamaguchi, Shogo; Kawamura, Taro; Masuda, Hiroyuki; Tanaka, Yoshio; Iida-Tanaka, Naoko; Takahara, Akira

    2010-01-01

    Effects of NIP-142, a benzopyran compound which terminates experimental atrial arrhythmia, on potassium channel alpha-subunits and mouse atrial repolarization were examined. NIP-142 concentration-dependently blocked the outward current through potassium channel alpha subunits Kv1.5, Kv4.2 and Kv4.3 expressed in Xenopus oocytes. In isolated mouse atrial myocardia, NIP-142 prolonged the action potential duration and effective refractory period, and increased the contractile force. These results suggest that NIP-142 blocks the potassium channels underlying the transient and sustained outward currents, which may contribute to its antiarrhythmic activity.

  16. A P-loop Mutation in G[alpha] Subunits Prevents Transition to the Active State: Implications for G-protein Signaling in Fungal Pathogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Bosch, Dustin E.; Willard, Francis S.; Ramanujam, Ravikrishna; Kimple, Adam J.; Willard, Melinda D.; Naqvi, Naweed I.; Siderovski, David P. (UNC); (Singapore)

    2012-10-23

    Heterotrimeric G-proteins are molecular switches integral to a panoply of different physiological responses that many organisms make to environmental cues. The switch from inactive to active G{alpha}{beta}{gamma} heterotrimer relies on nucleotide cycling by the G{alpha} subunit: exchange of GTP for GDP activates G{alpha}, whereas its intrinsic enzymatic activity catalyzes GTP hydrolysis to GDP and inorganic phosphate, thereby reverting G{alpha} to its inactive state. In several genetic studies of filamentous fungi, such as the rice blast fungus Magnaporthe oryzae, a G42R mutation in the phosphate-binding loop of G{alpha} subunits is assumed to be GTPase-deficient and thus constitutively active. Here, we demonstrate that G{alpha}(G42R) mutants are not GTPase deficient, but rather incapable of achieving the activated conformation. Two crystal structure models suggest that Arg-42 prevents a typical switch region conformational change upon G{alpha}{sub i1}(G42R) binding to GDP {center_dot} AlF{sub 4}{sup -} or GTP, but rotameric flexibility at this locus allows for unperturbed GTP hydrolysis. G{alpha}(G42R) mutants do not engage the active state-selective peptide KB-1753 nor RGS domains with high affinity, but instead favor interaction with G{beta}{gamma} and GoLoco motifs in any nucleotide state. The corresponding G{alpha}{sub q}(G48R) mutant is not constitutively active in cells and responds poorly to aluminum tetrafluoride activation. Comparative analyses of M. oryzae strains harboring either G42R or GTPase-deficient Q/L mutations in the G{alpha} subunits MagA or MagB illustrate functional differences in environmental cue processing and intracellular signaling outcomes between these two G{alpha} mutants, thus demonstrating the in vivo functional divergence of G42R and activating G-protein mutants.

  17. Binding of the Covalent Flavin Assembly Factor to the Flavoprotein Subunit of Complex II.

    Science.gov (United States)

    Maklashina, Elena; Rajagukguk, Sany; Starbird, Chrystal A; McDonald, W Hayes; Koganitsky, Anna; Eisenbach, Michael; Iverson, Tina M; Cecchini, Gary

    2016-02-05

    Escherichia coli harbors two highly conserved homologs of the essential mitochondrial respiratory complex II (succinate:ubiquinone oxidoreductase). Aerobically the bacterium synthesizes succinate:quinone reductase as part of its respiratory chain, whereas under microaerophilic conditions, the quinol:fumarate reductase can be utilized. All complex II enzymes harbor a covalently bound FAD co-factor that is essential for their ability to oxidize succinate. In eukaryotes and many bacteria, assembly of the covalent flavin linkage is facilitated by a small protein assembly factor, termed SdhE in E. coli. How SdhE assists with formation of the covalent flavin bond and how it binds the flavoprotein subunit of complex II remain unknown. Using photo-cross-linking, we report the interaction site between the flavoprotein of complex II and the SdhE assembly factor. These data indicate that SdhE binds to the flavoprotein between two independently folded domains and that this binding mode likely influences the interdomain orientation. In so doing, SdhE likely orients amino acid residues near the dicarboxylate and FAD binding site, which facilitates formation of the covalent flavin linkage. These studies identify how the conserved SdhE assembly factor and its homologs participate in complex II maturation.

  18. The AMP-activated protein kinase alpha2 catalytic subunit controls whole-body insulin sensitivity.

    Science.gov (United States)

    Viollet, Benoit; Andreelli, Fabrizio; Jørgensen, Sebastian B; Perrin, Christophe; Geloen, Alain; Flamez, Daisy; Mu, James; Lenzner, Claudia; Baud, Olivier; Bennoun, Myriam; Gomas, Emmanuel; Nicolas, Gaël; Wojtaszewski, Jørgen F P; Kahn, Axel; Carling, David; Schuit, Frans C; Birnbaum, Morris J; Richter, Erik A; Burcelin, Rémy; Vaulont, Sophie

    2003-01-01

    AMP-activated protein kinase (AMPK) is viewed as a fuel sensor for glucose and lipid metabolism. To better understand the physiological role of AMPK, we generated a knockout mouse model in which the AMPKalpha2 catalytic subunit gene was inactivated. AMPKalpha2(-/-) mice presented high glucose levels in the fed period and during an oral glucose challenge associated with low insulin plasma levels. However, in isolated AMPKalpha2(-/-) pancreatic islets, glucose- and L-arginine-stimulated insulin secretion were not affected. AMPKalpha2(-/-) mice have reduced insulin-stimulated whole-body glucose utilization and muscle glycogen synthesis rates assessed in vivo by the hyperinsulinemic euglycemic clamp technique. Surprisingly, both parameters were not altered in mice expressing a dominant-negative mutant of AMPK in skeletal muscle. Furthermore, glucose transport was normal in incubated isolated AMPKalpha2(-/-) muscles. These data indicate that AMPKalpha2 in tissues other than skeletal muscles regulates insulin action. Concordantly, we found an increased daily urinary catecholamine excretion in AMPKalpha2(-/-) mice, suggesting altered function of the autonomic nervous system that could explain both the impaired insulin secretion and insulin sensitivity observed in vivo. Therefore, extramuscular AMPKalpha2 catalytic subunit is important for whole-body insulin action in vivo, probably through modulation of sympathetic nervous activity.

  19. Nuclear factor YY1 activates the mammalian F0F1 ATP synthase alpha-subunit gene.

    Science.gov (United States)

    Breen, G A; Vander Zee, C A; Jordan, E M

    1996-01-01

    Analysis of the promoters of the bovine and human nuclear-encoded mitochondrial F0F1 ATP synthase alpha-subunit genes (ATPA) has identified several positive cis-acting regulatory regions that are important for basal promoter activity in human HeLa cells. We have previously determined that the binding of a protein factor, termed ATPF1, to an E-box sequence (CANNTG) located within one of these cis-acting regions is critical for transcriptional activation of the ATPA gene. In this article, we describe a second positive cis-acting regulatory element of the ATPA gene that is important for expression of the ATPA gene. We show that this cis-acting element also contains a binding site for a protein present in HeLa cells. On the basis of electrophoretic mobility shift patterns, oligonucleotide competition assays, and immunological cross-reactivity, we conclude that this protein factor is Yin-Yang 1 (YY1). Experiments carried out to examine the functional role of YY1 within the context of the ATPA promoter demonstrated that YY1 acts as a positive regulator of the ATPA gene. For example, when the YY1 binding site of the ATPA promoter was placed upstream of a reporter gene it was found to activate transcription in transient transfection assays. In addition, disruption of the YY1 binding site in the ATPA gene resulted in a loss of transcriptional activity. Furthermore, in cotransfection experiments overexpression of YY1 in trans was found to activate transcription of ATPA promoter-CAT constructs. Thus, at least two positive trans-acting regulatory factors, ATPF1 and YY1, are important for expression of the bovine and human F0F1 ATP synthase alpha-subunit genes.

  20. Archaeal translation initiation revisited: the initiation factor 2 and eukaryotic initiation factor 2B alpha-beta-delta subunit families

    Science.gov (United States)

    Kyrpides, N. C.; Woese, C. R.

    1998-01-01

    As the amount of available sequence data increases, it becomes apparent that our understanding of translation initiation is far from comprehensive and that prior conclusions concerning the origin of the process are wrong. Contrary to earlier conclusions, key elements of translation initiation originated at the Universal Ancestor stage, for homologous counterparts exist in all three primary taxa. Herein, we explore the evolutionary relationships among the components of bacterial initiation factor 2 (IF-2) and eukaryotic IF-2 (eIF-2)/eIF-2B, i.e., the initiation factors involved in introducing the initiator tRNA into the translation mechanism and performing the first step in the peptide chain elongation cycle. All Archaea appear to posses a fully functional eIF-2 molecule, but they lack the associated GTP recycling function, eIF-2B (a five-subunit molecule). Yet, the Archaea do posses members of the gene family defined by the (related) eIF-2B subunits alpha, beta, and delta, although these are not specifically related to any of the three eukaryotic subunits. Additional members of this family also occur in some (but by no means all) Bacteria and even in some eukaryotes. The functional significance of the other members of this family is unclear and requires experimental resolution. Similarly, the occurrence of bacterial IF-2-like molecules in all Archaea and in some eukaryotes further complicates the picture of translation initiation. Overall, these data lend further support to the suggestion that the rudiments of translation initiation were present at the Universal Ancestor stage.

  1. 1, 4-alpha-Glucan phosphorylase from Klebsiella pneumoniae purification, subunit structure and amino acid composition.

    Science.gov (United States)

    Linder, D; Kurz, G; Bender, H; Wallenfels, K

    1976-11-01

    1. A 1,4-alpha-glucan phosphorylase from Klebsiella pneumoniae has been purified about 80-fold with an over-all yield greater than 35%. The purified enzyme has been shown to be homogeneous by gel electrophoresis at different pH-values, by isoelectric focusing, by dodecylsulfate electrophoresis and by ultracentrifugation. 2. The molecular weight of the native enzyme has been determined to be 180 000 by ultra-centrifugation studies, in good agreement with the value of 189 000 estimated by gel permeation chromatography. 3. The enzyme dissociates in the presence of 0.1% dodecylsulfate or 5 M guanidine hydrochloride into polypeptide chains. The molecular weight of these polypeptide chains has been found to be 88 000 by dodecylsulfate polyacrylamide gel electrophoresis and 99 000 by sedimentation equilibrium studies, indicating that the native enzyme is composed of two polypeptide chains. 4. The enzyme contains pyridoxalphosphate with a stoichiometry of two moles per 180 000 g protein, confirming that the 1,4-alpha-glucan phosphorylase from Klebsiella pneumoniae is a dimeric enzyme. 5. The amino acid composition of the enzyme has been determined, and its correspondence to that of 1,4-alpha-glucan phosphorylases from other sources is discussed. 6. The pI of the enzyme has been shown to be 5.3 and its pH-optimum to be about pH 5.9. The enzyme is stable in the range from pH 5.9 to 10.5.

  2. Exploring the putative self-binding property of the human farnesyltransferase alpha-subunit.

    Science.gov (United States)

    Hagemann, Anna; Müller, Grit; Manthey, Iris; Bachmann, Hagen Sjard

    2017-09-26

    Farnesylation is an important post-translational protein modification in eukaryotes. Farnesylation is performed by protein farnesyltransferase, a heterodimer composed of an α- (FTα) and a β-subunit. Recently, homo-dimerization of truncated rat and yeast FTα has been detected, suggesting a new role for FTα homodimers in signal transduction. We investigated the putative dimerization behaviour of human and rat FTα. Different in vitro and in vivo approaches revealed no self-dimerization and a presumably artificial formation of homo-trimers and higher homo-oligomers in vitro. Our study contributes to the clarification of the physiological features of FTase in different species and may be important for the ongoing development of FTase inhibitors. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  3. Two novel functional mutations in the Na+,K+-ATPase alpha2-subunit ATP1A2 gene in patients with familial hemiplegic migraine and associated neurological phenotypes.

    NARCIS (Netherlands)

    Castro, M.J.; Nunes, B.; Vries, B. de; Lemos, C.; Molkot, K.R. van; Heuvel, J.J.M.W. van den; Temudo, T.; Barros, J.; Sequeiros, J.; Frants, R.R.; Koenderink, J.B.; Pereira-Monteiro, J.M.; Maagdenberg, A.M. van den

    2008-01-01

    Mutations in the ATP1A2 gene, encoding the alpha2-subunit of the Na+,K+-ATPase, are associated with familial hemiplegic migraine type 2. The majority of ATP1A2 mutations were reported in patients with hemiplegic migraine without any additional neurological findings. Here, we report on two novel ATP1

  4. Expression of the GABA(A) receptor alpha6 subunit in cultured cerebellar granule cells is developmentally regulated by activation of GABA(A) receptors

    DEFF Research Database (Denmark)

    Carlson, B X; Belhage, B; Hansen, G H

    1997-01-01

    , no significant change in [3H]Ro15-4513 binding was observed for the 56-kDa polypeptide. Immunolabeling of the alpha6 subunit using silver-enhanced, immuno-gold staining of granule cells showed a significant effect with THIP treatment only at 4 DIV and not at 8 DIV. Examination by light microscopy demonstrated...

  5. Mitochondrial cytochrome c oxidase subunit II variations predict adverse prognosis in cytogenetically normal acute myeloid leukaemia.

    Science.gov (United States)

    Silkjaer, Trine; Nyvold, Charlotte Guldborg; Juhl-Christensen, Caroline; Hokland, Peter; Nørgaard, Jan Maxwell

    2013-10-01

    Alterations in the two catalytic genes cytochrome c oxidase subunits I and II (COI and COII) have recently been suggested to have an adverse impact on prognosis in patients with acute myeloid leukaemia (AML). In order to explore this in further detail, we sequenced these two mitochondrial genes in diagnostic bone marrow or blood samples in 235 patients with AML. In 37 (16%) patients, a non-synonymous variation in either COI or COII could be demonstrated. No patients harboured both COI and COII non-synonymous variations. Twenty-four (10%) patients had non-synonymous variations in COI, whereas 13 (6%) patients had non-synonymous variations in COII. The COI and COII are essential subunits of cytochrome c oxidase that is the terminal enzyme in the oxidative phosphorylation complexes. In terms of disease course, we observed that in patients with a normal cytogenetic analysis at disease presentation (CN-AML) treated with curative intent, the presence of a non-synonymous variation in the COII was an adverse prognostic marker for both overall survival and disease-free survival (DFS) in both univariate (DFS; hazard ratio (HR) 4.4, P = 0.006) and multivariate analyses (DFS; HR 7.2, P = 0.001). This is the first demonstration of a mitochondrial aberration playing an adverse prognostic role in adult AML, and we argue that its role as a potentially novel adverse prognostic marker in the subset of CN-AML should be explored further.

  6. Plasminogen activator inhibitor type 1 interacts with alpha3 subunit of proteasome and modulates its activity.

    Science.gov (United States)

    Boncela, Joanna; Przygodzka, Patrycja; Papiewska-Pajak, Izabela; Wyroba, Elzbieta; Osinska, Magdalena; Cierniewski, Czeslaw S

    2011-02-25

    Plasminogen activator inhibitor type-1 (PAI-1), a multifunctional protein, is an important physiological regulator of fibrinolysis, extracellular matrix homeostasis, and cell motility. Recent observations show that PAI-1 may also be implicated in maintaining integrity of cells, especially with respect to cellular proliferation or apoptosis. In the present study we provide evidence that PAI-1 interacts with proteasome and affects its activity. First, by using the yeast two-hybrid system, we found that the α3 subunit of proteasome directly interacts with PAI-1. Then, to ensure that the PAI-1-proteasome complex is formed in vivo, both proteins were coimmunoprecipitated from endothelial cells and identified with specific antibodies. The specificity of this interaction was evidenced after transfection of HeLa cells with pCMV-PAI-1 and coimmunoprecipitation of both proteins with anti-PAI-1 antibodies. Subsequently, cellular distribution of the PAI-1-proteasome complexes was established by immunogold staining and electron microscopy analyses. Both proteins appeared in a diffuse cytosolic pattern but also could be found in a dense perinuclear and nuclear location. Furthermore, PAI-1 induced formation of aggresomes freely located in endothelial cytoplasm. Increased PAI-1 expression abrogated degradation of degron analyzed after cotransfection of HeLa cells with pCMV-PAI-1 and pd2EGFP-N1 and prevented degradation of p53 as well as IκBα, as evidenced both by confocal microscopy and Western immunoblotting.

  7. Characterization of a 7-kilodalton subunit of vaccinia virus DNA-dependent RNA polymerase with structural similarities to the smallest subunit of eukaryotic RNA polymerase II.

    Science.gov (United States)

    Amegadzie, B Y; Ahn, B Y; Moss, B

    1992-05-01

    A previously unrecognized 7-kDa polypeptide copurified with the DNA-dependent RNA polymerase of vaccinia virus virions. Internal amino acid sequences of the small protein matched a viral genomic open reading frame of 63 codons. Antipeptide antiserum was used to confirm the specific and complete association of the 7-kDa protein with RNA polymerase. The amino acid sequence predicted from the viral gene, named rpo7, was 23% identical to that of the smallest subunit of Saccharomyces cerevisiae RNA polymerase II, and a metal-binding motif, Cys-X-X-Cys-Gly, was located at precisely the same location near the N terminus in the two proteins. RNA analyses demonstrated early transcriptional initiation and termination signals in the rpo7 gene sequence. The viral RNA polymerase subunit was synthesized during the early phase of infection and continued to accumulate during the late phase.

  8. Promoter Structure of the RNA Polymerase II Large Subunit Gene in Caenorhabditis elegans and C. briggsae.

    Science.gov (United States)

    Bird, D M; Kaloshian, I; Molinari, S

    1997-06-01

    The 5'-end of the Caenorhabditis elegans ama-1 gene transcript, which encodes the largest subunit of RNA polymerase II, was cloned. Sequencing revealed that the message is trans-spliced. To characterize the Ce-ama-1 promoter, DNA sequence spanning 3 kb upstream from the initiation codon was determined. Typical elements, such as TATA and Spl sites, were absent. The homologue of ama-1 in C. briggsae, Cb-ama-1, was isolated and its 5' flanking sequence compared with that of Ce-ama-1, revealing only limited similarity, although both sequences included a potential initiator-class transcriptional regulator and phased repeats of an ATC motif. The latter elements are postulated to facilitate DNA bending and may play a role in transcription regulation.

  9. Analyzing proteasomal subunit expression reveals Rpt4 as a prognostic marker in stage II colorectal cancer.

    LENUS (Irish Health Repository)

    2012-02-01

    Colorectal cancer is a leading cause of cancer-related deaths worldwide. Early diagnosis and treatment of colorectal cancer is the key to improving survival rates and as such a need exists to identify patients who may benefit from adjuvant chemotherapy. The dysregulation of the ubiquitin-proteasome system (UPS) has been implicated in oncogenesis and cancer cell survival, and proteasome inhibitors are in clinical use for a number of malignancies including multiple myeloma. In our study, we examined the protein expression of several key components of the UPS in colorectal cancer using immunohistochemistry to determine expression levels of ubiquitinylated proteins and the proteasomal subunits, 20S core and Rpt4 in a cohort of 228 patients with colon cancer. Multivariate Cox analysis revealed that neither the intensity of either ubiquitinylated proteins or the 20S core was predictive in either Stage II or III colon cancer for disease free survival or overall survival. In contrast, in Stage II patients increased Rpt4 staining was significantly associated with disease free survival (Cox proportional hazard ratio 0.605; p = 0.0217). Our data suggest that Rpt4 is an independent prognostic variable for Stage II colorectal cancer and may aid in the decision of which patients undergo adjuvant chemotherapy.

  10. Identification of the alternative spliced form of the alpha 2/delta subunit of voltage sensitive Ca2+ channels expressed in PC12 cells.

    Science.gov (United States)

    Gilad, B; Shenkar, N; Halevi, S; Trus, M; Atlas, D

    1995-07-07

    The alpha 2/delta subunit of voltage sensitive Ca2+ channels expressed in PC12 has been cloned and partially sequenced. The message observed in Northern blot analysis displays a 7.5 kb transcript, identical in size to mRNA of rabbit skeletal muscle and rat brain. The nucleotide sequence of the cloned alpha 2 subunit of the PC12 specific cDNA is > 99% identical to rat brain sequence and 85% to skeletal muscle. Reverse-transcriptase-polymerase chain reaction (RT-PCR) of the alternative splicing region identifies two deleted regions of 57 bp and 21 bp in PC12 expressed alpha 2/delta transcript. The alternative variant alpha 2e of alpha 2/delta subunit which is expressed in PC12 cells was previously identified in human embryonic kidney (HEK293) cells. RT-PCR analysis show two different sized alternative PCR fragments in rat lung and none in rat spleen, kidney and intestine. Antibodies prepared against a 19 amino acid peptide within the alternative spliced region effectively inhibits [3H]dopamine release in PC12 cells. This implies that the alternatively spliced region is positioned extracellularly and is involved in regulation of the L-type Ca2+ channel-mediated transmitter release.

  11. Molecular cloning and expression analysis of cytochrome c oxidase subunit II from Sitophilus zeamais.

    Science.gov (United States)

    Hou, Chang-Liang; Wang, Jing-Bo; Wu, Hua; Liu, Jia-Yu; Ma, Zhi-Qing; Feng, Jun-Tao; Zhang, Xing

    2016-09-30

    Cytochrome c oxidase subunit II (COX II) containing a dual core CuA active site is one of the core subunits of mitochondrial Cytochrome c oxidase (Cco), which plays a significant role in the physiological process. In this report, the full-length cDNA of COXII gene was cloned from Sitophilus zeamais, which had an open reading frame (ORF) of 684 bp encoding 227 amino acids residues. The predicted COXII protein had a molecular mass of 26.2 kDa with pI value of 6.37. multiple sequence alignment and phylogenetic analysis indicated that Sitophilus zeamais COXII had high sequence identity with the COXII of other insect species. The gene was subcloned into the expression vector pET-32a, and induced by isopropyl β-d-thiogalactopyranoside (IPTG) in E. coli Transetta (DE3) expression system. Finally the recombinant COXII with 6-His tag was purified using affinity chromatography with Ni(2+)-NTA agarose. Western Blotting (WB) showed the recombinant protein was about 44 kD, and the concentration of fusion protein was 50 μg/mL. UV-spectrophotometer and infrared spectrometer analysis showed that recombinant COXII could catalyze the oxidation of substrate Cytochrome C (Cyt c), and influenced by allyl isothiocyanate (AITC). By using molecular docking method, It was found that a sulfur atom of AITC structure could form a length of 2.9 Å hydrogen bond with Leu-31. These results suggested that tag-free COXII was functional and one of the action sites of AITC, which will be helpful to carry out a point mutation in binding sites for the future research.

  12. Localization of a new type of X-linked liver glycogenosis to the chromosomal region Xp22 containing the liver {alpha}-subunit of phosphorylase kinase (PHKA2)

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickx, J.; Coucke, P.; Willems, P.J. [Univ. of Antwerp (Belgium)] [and others

    1994-06-01

    The authors describe here a new type of X-linked liver glycogen storage disease. The main symptoms include liver enlargement and growth retardation. The clinical and biochemical abnormalities of this glycogenosis are similar to those of classical X-linked liver glycogenosis due to phosphorylase kinase deficiency (XLG). However, in constrast to patients with XLG, the patients described here have no reduced phosphorylase kinase activity in erythrocytes and leukocytes, and no enzyme deficiency could be found. Linkage analysis of four families with this X-linked type of liver glycogenosis assigned the disease gene to Xp22. Lod scores obtained with the markers DXS987, DXS207, and DXS999 were 3.97, 2.71, and 2.40, respectively, all at 0% recombination. Multipoint linkage analysis localized the disease gene between DXS143 and DXS989 with a maximum lod score of 4.70 at {theta}=0, relative to DXS987. As both the classical XLG gene and the liver {alpha}-subunit of PHK (PHKA2) are also located in Xp22, this variant type of XLG may be allelic to classical XLG, and both diseases may be caused by mutations in PHKA2. Therefore, they propose to classify XLG as XLG type I (the classical type of XLG) and XLG type II (the variant type of XLG). 28 refs., 2 figs., 3 tabs.

  13. Association of nicotinic acetylcholine receptor subunit alpha-4 polymorphisms with smoking behaviors in Chinese male smokers

    Institute of Scientific and Technical Information of China (English)

    CHU Cheng-jing; YANG Yan-chun; WEI Jin-xue; ZHANG Lan

    2011-01-01

    Background It has been reported that the nicotinic acetylcholine receptor subunit a4 gene (CHRNA4) might be associated with smoking behaviors in the previous studies. Up to now, there are few reports on the relationship between CHRNA4 and smoking initiation. In this study, we tried to explore the role of two polymorphisms in CHRNA4 (rs 1044396 and rs 1044397) in smoking initiation and nicotine dependence in Chinese male smokers.Methods Nine hundred and sixty-six Chinese male lifetime nonsmokers and smokers were assessed by the Fagerstr(o)m test for nicotine dependence (FTND), smoking quantity (SQ) and the heaviness of smoking index (HSI). All subjects were divided into four groups based on their tobacco use history and the FTND scores. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was performed to find two polymorphisms of CHRNA4 in these subjects.Results The x2 test showed that rs1044396 was significantly associated with smoking initiation (x2=4.65, P=0.031),while both rs1044396 and rs1044397 were significantly associated with nicotine dependence (x2=5.42, P=0.020; x2=758,P=0.005). Furthermore, the T-G (3.9%) haplotype of rs1044396-rs1044397 showed significant association with smoking initiation (x2=6.30, P=0.012) and the C-G haplotype (58.9%) remained positive association with nicotine dependence (x2=8.64, P=0.003) after Bonferroni correction. The C-G haplotype also significantly increased the HSI (P=0.002) and FTND scores (P=0.001) after Bonferroni correction.Conclusion These findings suggest that CHRNA4 may be associated with smoking initiation and the C-G haplotype of rs1044396-rs1044397 might increase the vulnerability to nicotine dependence in Chinese male smokers.

  14. Conformational stability analyses of alpha subunit I domain of LFA-1 and Mac-1.

    Directory of Open Access Journals (Sweden)

    Debin Mao

    Full Text Available β₂ integrin of lymphocyte function-associated antigen-1 (LFA-1 or macrophage-1 antigen (Mac-1 binds to their common ligand of intercellular adhesion molecule-1 (ICAM-1 and mediates leukocyte-endothelial cell (EC adhesions in inflammation cascade. Although the two integrins are known to have distinct functions, the corresponding micro-structural bases remain unclear. Here (steered-molecular dynamics simulations were employed to elucidate the conformational stability of α subunit I domains of LFA-1 and Mac-1 in different affinity states and relevant I domain-ICAM-1 interaction features. Compared with low affinity (LA Mac-1, the LA LFA-1 I domain was unstable in the presence or absence of ICAM-1 ligand, stemming from diverse orientations of its α₇-helix with different motifs of zipper-like hydrophobic junction between α₁- and α₇-helices. Meanwhile, spontaneous transition of LFA-1 I domain from LA state to intermediate affinity (IA state was first visualized. All the LA, IA, and high affinity (HA states of LFA-1 I domain and HA Mac-1 I domain were able to bind to ICAM-1 ligand effectively, while LA Mac-1 I domain was unfavorable for binding ligand presumably due to the specific orientation of S144 side-chain that capped the MIDAS ion. These results furthered our understanding in correlating the structural bases with their functions of LFA-1 and Mac-1 integrins from the viewpoint of I domain conformational stability and of the characteristics of I domain-ICAM-1 interactions.

  15. Small angle X-ray scattering of wheat seed-storage proteins: alpha-, gamma- and omega-gliadins and the high molecular weight (HMW) subunits of glutenin.

    Science.gov (United States)

    Thomson, N H; Miles, M J; Popineau, Y; Harries, J; Shewry, P; Tatham, A S

    1999-03-19

    Small angle X-ray scattering in solution was performed on seed-storage proteins from wheat. Three different groups of gliadins (alpha-, gamma- and omega-) and a high molecular weight (HMW) subunit of glutenin (1Bx20) were studied to determine molecular size parameters. All the gliadins could be modelled as prolate ellipsoids with extended conformations. The HMW subunit existed as a highly extended rod-like particle in solution with a length of about 69 nm and a diameter of about 6.4 nm. Specific aggregation effects were observed which may reflect mechanisms of self-assembly that contribute to the unique viscoelastic properties of wheat dough.

  16. Mutation Analysis of 16 Mucolipidosis II and III Alpha/Beta Chinese Children Revealed Genotype-Phenotype Correlations

    Science.gov (United States)

    Liu, Shuang; Zhang, Weimin; Shi, Huiping; Yao, Fengxia; Wei, Min; Qiu, Zhengqing

    2016-01-01

    Mucolipidosis II and III alpha/beta are autosomal recessive diseases caused by mutations in the GNPTAB gene which encodes the α and β subunits of the N-acetylglucosamine-1-phosphotransferase. Clinically, mucolipidosis II (MLII) is characterized by severe developmental delay, coarse facial features, skeletal deformities, and other systemic involvement. In contrast, MLIII alpha/beta is a much milder disorder, the symptoms of which include progressive joint stiffness, short stature, and scoliosis. To study the relationship between the genotypes and phenotypes of the MLII and MLIII alpha/beta patients, we analyzed the GNPTAB gene in 16 Chinese MLII and MLIII alpha/beta patients. We collected and analyzed the patients’ available clinical data and all showed clinical features typical of MLII or MLIII alpha/beta. Moreover, the activity of several lysosomal enzymes was measured in the plasma and finally the GNPTAB gene was sequenced. We detected 30 mutant alleles out of 32 alleles in our patients. These include 10 new mutations (c.99delC, c.118-1G>A, c.523_524delAAinsG, c.1212C>G, c.2213C>A, c.2345C>T, c.2356C>T, c.2455G>T, c.2821dupA, and c.3136-2A>G) and 5 previously reported mutations (c.1071G>A, c.1090C>T, c.2715+1G>A, c.2550_2554delGAAA, and c.3613C>T). The most frequent mutation was the splicing mutation c.2715+1G>A, which accounted for 28% of the mutations. The majority of the mutations reported in the Chinese patients (57%) were located on exon 13 or in its intronic flanking regions. PMID:27662472

  17. Cross-linking of the delta subunit to one of the three alpha subunits has no effect on functioning, as expected if delta is a part of the stator that links the F1 and F0 parts of the Escherichia coli ATP synthase.

    Science.gov (United States)

    Ogilvie, I; Aggeler, R; Capaldi, R A

    1997-06-27

    A mutant of the Escherichia coli F1F0-ATPase has been generated (alphaQ2C) in which the glutamine at position 2 of the alpha subunit has been replaced with a cysteine residue. Cu2+ treatment of ECF1 from this mutant cross-linked an alpha subunit to the delta subunit in high yield. Two different sites of disulfide bond formation were involved, i.e. between Cys90 (or the closely spaced Cys47) of alpha with Cys140 of delta, and between Cys2 of alpha and Cys140 of delta. Small amounts of other cross-linked products, including alpha-alpha, delta internal, and alpha-alpha-delta were obtained. In ECF1F0, there was no cross-linking between the intrinsic Cys of alpha and Cys140. Instead, the product generated between Cys2 of alpha and Cys140 of delta was obtained at near 90% yield. Small amounts of alpha-alpha and delta internal were present, and under high Cu2+ concentrations, alpha-alpha-delta was also formed. The ATPase activity of ECF1 and ECF1F0 was not significantly affected by the presence of these cross-links. When Cys140 of delta was first modified with N-ethylmaleimide in ECF1F0, an alpha-delta cross-link was still produced, although in lower yield, between Cys64 of delta and Cys2 of alpha. ATP hydrolysis-linked proton pumping of inner membranes from the mutant alpha2QC was only marginally affected by cross-linking of the alpha to the delta subunit. These results indicate that Cys140 and Cys64 of the delta subunit and Cys2 of the alpha subunit are in close proximity. This places the delta subunit near the top of the alpha-beta hexagon and not in the stalk region. As fixing the delta to the alpha by cross-linking does not greatly impair either the ATPase function of the enzyme, or coupled proton translocation, we argue that the delta subunit forms a portion of the stator linking F1 to F0.

  18. Functional analysis of Trichoderma reesei CKIIα2, a catalytic subunit of casein kinase II.

    Science.gov (United States)

    Wang, Mingyu; Yang, Hui; Zhang, Meiling; Liu, Kuimei; Wang, Hanbin; Luo, Yi; Fang, Xu

    2015-07-01

    Trichoderma reesei is the most important industrial cellulase-producing filamentous fungus. Although its molecular physiology has been investigated, the signal transduction pathways are not fully understood. In particular, the role of casein kinase II (CKII) is not yet clear. In this work, we carried out functional investigations on a catalytic subunit of CKII, CKIIα2. Comparison of the phenotypic features of T. reesei parent and Δck2α2 strains showed significant changes following ck2α2 disruption. T. reesei Δck2α2 form significantly smaller mycelial pellets in glucose-containing liquid minimum media, have shorter and fewer branch hyphae, produce smaller amounts of chitinases, produce more spores, show more robust growth on glucose-containing agar plates, and consume glucose at a significantly higher rate. Suggestions can be made that CKIIα2 governs chitinase expression, and the disruption of ck2α2 results in lower levels of chitinase production, leading to a weaker cell wall disruption capability, further resulting in weaker hyphal branching, which eventually leads to smaller mycelial pellets in liquid media. Further conclusions can be made that CKIIα2 is involved in repression of sporulation and glucose metabolism, which is consistent with the proposal that CKIIα2 represses global metabolism. These observations make the deletion of ck2α2 a potentially beneficial genetic disruption for T. reesei during industrial applications, as smaller mycelial pellets, more spores and more robust glucose metabolism are all desired traits for industrial fermentation. This work reports novel unique functions of a CKII catalytic subunit and is also the first genetic and physiological investigation on CKII in T. reesei.

  19. Immunogenicity of P/Q-type calcium channel in small cell lung cancer: investigation of alpha1 subunit polyglutamine expansion.

    Science.gov (United States)

    Black, J L; Nelson, T R; Snow, K; Lennon, V A

    1999-12-01

    The ectopic expression of neuronal P/Q-type voltage-gated calcium channels in small cell lung carcinoma (SCLC) is thought to induce antisynaptic autoimmunity in the paraneoplastic Lambert-Eaton myasthenic syndrome. The gene CACNL1A4, encoding the principal (alpha1A) subunit of this calcium channel, is mutated in several inherited neurological disorders. One of these disorders (spinocerebellar ataxia, type 6, or SCA-6) involves the expansion of a trinucleotide (CAG) repeat unit. We hypothesized that a somatic CAG repeat instability of this gene in neoplastic cells might generate a non-self epitope capable of initiating autoimmunity to P/Q-type calcium channels. We therefore analyzed the CACNL1A4 gene in SCLC lines established from metastases derived from seven individual patients (four associated with Lambert-Eaton myasthenic syndrome, one associated with myasthenia gravis, and two not associated with neurological autoimmunity). We compared their CAG repeat numbers (determined by polymerase chain reaction (PCR) amplification followed by separation of products on a 6% polyacrylamide/8M urea gel) to published norms and to DNA from a patient with SCA-6. The number of CAG repeats in SCLC DNA fell within a normal range whether or not the neoplasm was complicated by neurological autoimmunity. Therefore, it is unlikely that somatically unstable CAG repeat units in the gene encoding the P/Q-type voltage-gated calcium channel account for this tumor protein's immunogenicity in the Lambert-Eaton myasthenic syndrome.

  20. Control of yeast mating signal transduction by a mammalian. beta. sub 2 -adrenergic receptor and G sub s. alpha. subunit

    Energy Technology Data Exchange (ETDEWEB)

    King, K.; Caron, M.G.; Lefkowitz, R.J. (Duke Univ. Medical Center, Durham, NC (USA)); Dohlman, H.G.; Thorner, J. (Univ. of California, Berkeley (USA))

    1990-10-05

    To facilitate functional and mechanistic studies of receptor-G protein interactions by expression of the human {beta}{sub 2}-adrenergic receptor (h{beta}-AR) has been expressed in Saccharomyces cerevisiae. This was achieved by placing a modified h{beta}-AR gene under control of the galactose-inducible GAL1 promoter. After induction by galactose, functional h{beta}-AR was expressed at a concentration several hundred times as great as that found in any human tissue. As determined from competitive ligand binding experiments, h{beta}-AR expressed in yeast displayed characteristic affinities, specificity, and stereoselectivity. Partial activation of the yeast pheromone response pathway by {beta}-adrenergic receptor agonists was achieved in cells coexpressing h{beta}-AR and a mammalian G protein (G{sub s}) {alpha} subunit - demonstrating that these components can couple to each other and to downstream effectors when expressed in yeast. This in vivo reconstitution system provides a new approach for examining ligand binding and G protein coupling to cell surface receptors.

  1. Condensin II subunit dCAP-D3 restricts retrotransposon mobilization in Drosophila somatic cells.

    Directory of Open Access Journals (Sweden)

    Andrew T Schuster

    2013-10-01

    Full Text Available Retrotransposon sequences are positioned throughout the genome of almost every eukaryote that has been sequenced. As mobilization of these elements can have detrimental effects on the transcriptional regulation and stability of an organism's genome, most organisms have evolved mechanisms to repress their movement. Here, we identify a novel role for the Drosophila melanogaster Condensin II subunit, dCAP-D3 in preventing the mobilization of retrotransposons located in somatic cell euchromatin. dCAP-D3 regulates transcription of euchromatic gene clusters which contain or are proximal to retrotransposon sequence. ChIP experiments demonstrate that dCAP-D3 binds to these loci and is important for maintaining a repressed chromatin structure within the boundaries of the retrotransposon and for repressing retrotransposon transcription. We show that dCAP-D3 prevents accumulation of double stranded DNA breaks within retrotransposon sequence, and decreased dCAP-D3 levels leads to a precise loss of retrotransposon sequence at some dCAP-D3 regulated gene clusters and a gain of sequence elsewhere in the genome. Homologous chromosomes exhibit high levels of pairing in Drosophila somatic cells, and our FISH analyses demonstrate that retrotransposon-containing euchromatic loci are regions which are actually less paired than euchromatic regions devoid of retrotransposon sequences. Decreased dCAP-D3 expression increases pairing of homologous retrotransposon-containing loci in tissue culture cells. We propose that the combined effects of dCAP-D3 deficiency on double strand break levels, chromatin structure, transcription and pairing at retrotransposon-containing loci may lead to 1 higher levels of homologous recombination between repeats flanking retrotransposons in dCAP-D3 deficient cells and 2 increased retrotransposition. These findings identify a novel role for the anti-pairing activities of dCAP-D3/Condensin II and uncover a new way in which dCAP-D3/Condensin

  2. NR2 subunits and NMDA receptors on lamina II inhibitory and excitatory interneurons of the mouse dorsal horn

    Directory of Open Access Journals (Sweden)

    MacDermott Amy B

    2010-05-01

    Full Text Available Abstract Background NMDA receptors expressed by spinal cord neurons in the superficial dorsal horn are involved in the development of chronic pain associated with inflammation and nerve injury. The superficial dorsal horn has a complex and still poorly understood circuitry that is mainly populated by inhibitory and excitatory interneurons. Little is known about how NMDA receptor subunit composition, and therefore pharmacology and voltage dependence, varies with neuronal cell type. NMDA receptors are typically composed of two NR1 subunits and two of four NR2 subunits, NR2A-2D. We took advantage of the differences in Mg2+ sensitivity of the NMDA receptor subtypes together with subtype preferring antagonists to identify the NR2 subunit composition of NMDA receptors expressed on lamina II inhibitory and excitatory interneurons. To distinguish between excitatory and inhibitory interneurons, we used transgenic mice expressing enhanced green fluorescent protein driven by the GAD67 promoter. Results Analysis of conductance ratio and selective antagonists showed that lamina II GABAergic interneurons express both the NR2A/B containing Mg2+ sensitive receptors and the NR2C/D containing NMDA receptors with less Mg2+ sensitivity. In contrast, excitatory lamina II interneurons express primarily NR2A/B containing receptors. Despite this clear difference in NMDA receptor subunit expression in the two neuronal populations, focally stimulated synaptic input is mediated exclusively by NR2A and 2B containing receptors in both neuronal populations. Conclusions Stronger expression of NMDA receptors with NR2C/D subunits by inhibitory interneurons compared to excitatory interneurons may provide a mechanism to selectively increase activity of inhibitory neurons during intense excitatory drive that can provide inhibitory feedback.

  3. Biosensor analysis of dynamics of interleukin 5 receptor subunit beta(c) interaction with IL5:IL5R(alpha) complexes.

    Science.gov (United States)

    Scibek, Jeffery J; Evergren, Emma; Zahn, Stefan; Canziani, Gabriela A; Van Ryk, Donald; Chaiken, Irwin M

    2002-08-15

    To gain insight into IL5 receptor subunit recruitment mechanism, and in particular the experimentally elusive pathway for assembly of signaling subunit beta(c), we constructed a soluble beta(c) ectodomain (s(beta)(c)) and developed an optical biosensor assay to measure its binding kinetics. Functionally active s(beta)(c) was anchored via a C-terminal His tag to immobilized anti-His monoclonal antibodies on the sensor surface. Using this surface, we quantitated for the first time direct binding of s(beta)(c) to IL5R(alpha) complexed to either wild-type or single-chain IL5. Binding was much weaker if at all with either R(alpha) or IL5 alone. Kinetic evaluation revealed a moderate affinity (0.2-1 microM) and relatively fast off rate for the s(beta)(c) interaction with IL5:R(alpha) complexes. The data support a model in which beta(c) recruitment occurs with preformed IL5:R(alpha) complex. Dissociation kinetics analysis suggests that the IL5-alpha-beta(c) complex is relatively short-lived. Overall, this study solidifies a model of sequential recruitment of receptor subunits by IL5, provides a novel biosensor binding assay of beta(c) recruitment dynamics, and sets the stage for more advanced characterization of the roles of structural elements within R(alpha), beta(c), and cytokines of the IL5/IL3/GM-CSF family in receptor recruitment and activation.

  4. [Altered expression of L-type calcium channel alpha1C and alpha1D subunits in colon of rats with diarrhea-predominant irritable bowel syndrome].

    Science.gov (United States)

    Zhu, Jie; Luo, He-Sheng; Chen, Ling; Zhou, Ting

    2009-10-20

    To investigate the molecular identities of L-type calcium channel alpha1C subunit (Cav1.2) and alpha1D subunit (Cav1.3) responsible for motor dysfunction of diarrhea-predominant irritable bowel syndrome (D-IBS). A total of 30 male Wistar rats were randomly divided into two groups. The traditional method for irritable bowel syndrome in a cold environment and intragastric administration of Folium Cassiae were combined to develop the D-IBS model. The fecal particles of rats and the water content in feces were measured. Then the expression of Cav1.2 and Cav1.3 mRNA was detected by reverse transcription polymerase chain reaction. The expressions of Cav1.2 and Cav1.3 were examined by immunohistochemistry in colonic tissues from D-IBS model rats and matched tissues. The fecal particles and the water content in feces of D-IBS model rats significantly increased as compared with the normal rats (6.8 +/- 1.4 vs 3.2 +/- 0.8, P = 0.032, 80% +/- 4% vs 47% +/- 5%, P = 0.018). Cav1.2 and Cav1.3 were positively expressed in colon of both model group and control group rats. The immunohistochemical scores of Cav1.2 and Cav1.3 expression increased in colon of D-IBS model rats as compared with those in normal control rats (3.43 +/- 0.92 vs 2.82 +/- 0.60, P = 0.034, 4.32 +/- 0.51 vs 3.75 +/- 1.05, P = 0.039). The immunohistochemical scores of Cav1.3 expression were significantly higher than Cav1.2 in colon of both two group rats (P = 0.003, 0.005). Similarly, the expression of Cav1.2 and Cav1.3 mRNA increased in colon of D-IBS model rats as compared with those in normal control rats (1.18 +/- 0.15 vs 1.06 +/- 0.12, P = 0.023, 1.32 +/- 0.13 vs 1.23 +/- 0.13, P = 0.033). The expression of Cav1.3 mRNA was significantly higher than Cav1.2 in colon of both two group rats (P = 0.038, 0.012). The traditional modeling of irritable bowel syndrome in rats alters the expression of Cav1.2 and Cav1.3. It may be directly related to the generation of enhanced colonic contraction in D-IBS. In addition

  5. Mobilities of the inner three core residues and the Man(alpha 1--6) branch of the glycan at Asn78 of the alpha-subunit of human chorionic gonadotropin are restricted by the protein.

    Science.gov (United States)

    van Zuylen, C W; de Beer, T; Leeflang, B R; Boelens, R; Kaptein, R; Kamerling, J P; Vliegenthart, J F

    1998-02-17

    Human chorionic gonadotropin (hCG) is a heterodimeric glycoprotein hormone involved in the maintenance of the corpus luteum in early pregnancy. The free alpha-subunit of hCG has a biological activity of its own, namely, stimulation of prolactin secretion from term pregnancy decidual cells [Blithe, D. L., et al. (1991) Endocrinology 129, 2257-2259]. Glycosylation at Asn78 of the alpha-subunit is required for the stability of the protein, but the exact nature of the stabilizing effect is not known. In our previous study, it was indicated that GlcNAc-1 at Asn78 has a reduced mobility, whereas the glycan at Asn52 is highly mobile [De Beer, T., et al. (1996) Eur. J. Biochem. 241, 229-242]. In the present investigation, it is shown that the PNGase F susceptibility of the Asn52-linked glycan in the free alpha-subunit is absent in the heterodimer. Thus, the high mobility of the glycan at Asn52 may be characteristic for the free alpha-subunit. For accurate modeling of alpha hCG, knowledge of the behavior of each of the glycans is essential. In this context, the mobility of the glycans and their interactions with the protein are explored by NMR spectroscopy using desialylated, partially deglycosylated free alpha-subunit (as-pd alpha) carrying glycans at Asn78 only. NOEs between GlcNAc-2 and several amino acid residues indicate that GlcNAc-2 is involved in stabilizing alpha hCG. From the values of 13C relaxation parameters T2 and T1 rho of the constituting monosaccharide residues, it was concluded that the inner three residues have a severely restricted mobility. The Man-4 and Man-4' residues of the diantennary oligosaccharide exhibit a similar relaxation behavior, suggesting that the Man-4' branch occurs in a single conformation of the C5-C6 linkage of Man-3 instead of in rapidly interconverting conformations that are known to exist for this linkage for the free oligosaccharide.

  6. Wheat and barley allergens associated with baker's asthma. Glycosylated subunits of the alpha-amylase-inhibitor family have enhanced IgE-binding capacity.

    Science.gov (United States)

    Sanchez-Monge, R; Gomez, L; Barber, D; Lopez-Otin, C; Armentia, A; Salcedo, G

    1992-01-15

    A 16 kDa protein, designated CM16*, which strongly binds IgE from baker's-asthma patients has been identified as a glycosylated form of the previously reported WTAI-CM16, which is a subunit of the wheat tetrameric alpha-amylase inhibitor. A glycosylated form (CMb*) of BTAI-CMb, the equivalent inhibitor subunit from barley, has been also found to have significantly enhanced IgE-binding capacity. In all, 14 purified members of the alpha-amylase/trypsin-inhibitor family showed very different IgE-binding capacities when tested by a dot-blot assay. The glycosylated components CM16*, CMb* and the previously described non-glycosylated 14.5 kDa allergen from barley (renamed BMAI-1) were found to be the strongest allergens.

  7. Further studies on the covalent crosslinking of thyrotropin to its receptor: evidence that both the alpha and beta subunits of thyrotropin are crosslinked to the receptor.

    Science.gov (United States)

    McQuade, R; Thomas, C G; Nayfeh, S N

    1987-02-01

    Highly purified alpha- and beta-subunits of thyrotropin were individually radioiodinated and, subsequently, recombined with their unlabeled complementary subunits. This procedure resulted in the formation of [125I]thyrotropin(TSH) hybrid molecules which were labeled on only one hormone subunit. Characterization of the binding properties of these two hybrid molecules demonstrated that both yielded nonlinear Scatchard plots with Kd and Bmax values similar to those obtained with radioiodinated native TSH and that both were capable of interaction with the high- and low-affinity binding components of the TSH receptor. The recombined [125I]TSH molecules were then crosslinked to the TSH receptor using disuccinimidyl suberate. Following electrophoresis and autoradiography, two labeled TSH-receptor complexes with Mr of 68,000 and 80,000 were observed. These two complexes exhibited hormone specificity and electrophoretic mobility identical to those previously observed using native [125I]TSH. Crosslinking with increasing concentrations of disuccinimidyl suberate suggested that the formation of the 68,000 and 80,000 complexes was sequential with the 68,000 appearing before the 80,000. Furthermore, the two bands were labeled regardless of which TSH subunit of the hybrid TSH was radioiodinated. These data strongly suggest that the 68,000 and 80,000 TSH-receptor complexes are the result of crosslinking to the TSH alpha-beta dimer and not to one subunit in the case of the 68,000 complex and to the TSH alpha-beta dimer in the case of the 80,000 complex, as had been hypothesized previously.

  8. Characterization of a novel monoclonal antibody with restricted specificity to the free beta 2 integrin alpha M CD11b subunit.

    Science.gov (United States)

    Tanfous, Naouel Guedel-Ben; Essafi, Makram; Larguech, Beya; Barbouche, Ridha; Fathallah, Dahmani M

    2007-12-01

    Leukocyte cell surface expression and function of beta2 integrins require the intracellular association of alpha subunits, CD11a, b, c, d, respectively, with the common CD18 beta2 subunit. We have raised and characterized a murine MAb -- ME-MDF -- directed against the low affinity form of the human integrin alphaM subunit CD11b A-domain. MAb ME-MDF is an IgG2a that has a kDa of 2,45461 +/- 0.12 x 10(-9) M. MAb ME-MDF recognizes both the low and high affinity forms of the CD11b A-domain. Flow cytometry showed that ME-MDF does not recognize the heterodimeric CD11b/CD18 molecule at the surface of polymorphonuclear cells and the human monoblast cell line U937. Western blot analysis of U937 cell line cell surface proteins demonstrated that ME-MDF reacts specifically with the CD11b subunit but does not react with the heterodimeric CD11b/CD18 complex, a feature that differentiates it from other CD11b A-dom-specific MAbs. These observations suggest that ME-MDF recognizes an epitope that is involved in the association of the two subunits and hence is not accessible within the heterodimeric form of the CD11b/CD18 molecule. These data show that the CD11b A-dom engages not only the MIDAS but also the ME-MDF-specific epitope to associate with the CD18 subunit. We have also constructed, and expressed in the yeast Pichia pastoris, the corresponding recombinant scFv form of MAb ME-MDF and characterized the CDRs. MAb ME-MDF is characterized by short VH and VL CDR3. MAb ME-MDF and/or its recombinant scFv form would be very useful to study the structural basis of the association between the alpha and beta2 integrin subunits and to investigate the possibility of modulating CR3 cell surface expression by preventing subunit association.

  9. Alpha-subunit positions methionine 180 and glutamate 214 of Pseudomonas stutzeri OX1 toluene-o-xylene monooxygenase influence catalysis.

    Science.gov (United States)

    Vardar, Gönül; Wood, Thomas K

    2005-02-01

    Alpha-subunit position M180 of toluene-o-xylene monooxygenase influences the regiospecific oxidation of aromatics (e.g., from o-cresol, M180H forms 3-methylcatechol, methylhydroquinone, and 4-methylresorcinol, whereas the wild type forms only 3-methylcatechol). Position E214 influences the rate of reaction (e.g., E214G increases p-nitrophenol oxidation 15-fold) by controlling substrate entrance and product efflux as a gate residue.

  10. $Ly \\alpha$ Fluorescent Excitation of FeII in Active Galactic Nuclei

    CERN Document Server

    Sigut, T A A; Pradhan, Anil K.

    1998-01-01

    We have calculated FeII emission line strengths for Active Galactic Nuclei Broad-Line Regions using precise radiative transfer and Iron Project atomic data. We improve the treatment of all previously considered excitation mechanisms for the FeII emission, continuum fluorescence, collisional excitation, fluorescence by self-overlap among the iron lines, and fluorescent excitation by Lyman-alpha. We demonstrate that Lyman-alpha fluorescence is of fundamental importance in determining the strength of the FeII emission. In addition to enhancing the ultraviolet and optical FeII flux, Lyman-alpha fluorescence also results in significant near-infrared FeII emission in the 8500-9500 Angstrom wavelength range. New observations are suggested to probe this effect in strong FeII emitting quasars.

  11. Analysis of the cytochrome c oxidase subunit II (COX2) gene in giant panda, Ailuropoda melanoleuca.

    Science.gov (United States)

    Ling, S S; Zhu, Y; Lan, D; Li, D S; Pang, H Z; Wang, Y; Li, D Y; Wei, R P; Zhang, H M; Wang, C D; Hu, Y D

    2017-01-23

    The giant panda, Ailuropoda melanoleuca (Ursidae), has a unique bamboo-based diet; however, this low-energy intake has been sufficient to maintain the metabolic processes of this species since the fourth ice age. As mitochondria are the main sites for energy metabolism in animals, the protein-coding genes involved in mitochondrial respiratory chains, particularly cytochrome c oxidase subunit II (COX2), which is the rate-limiting enzyme in electron transfer, could play an important role in giant panda metabolism. Therefore, the present study aimed to isolate, sequence, and analyze the COX2 DNA from individuals kept at the Giant Panda Protection and Research Center, China, and compare these sequences with those of the other Ursidae family members. Multiple sequence alignment showed that the COX2 gene had three point mutations that defined three haplotypes, with 60% of the sequences corresponding to haplotype I. The neutrality tests revealed that the COX2 gene was conserved throughout evolution, and the maximum likelihood phylogenetic analysis, using homologous sequences from other Ursidae species, showed clustering of the COX2 sequences of giant pandas, suggesting that this gene evolved differently in them.

  12. Reactions of a fluorescent ATP analog, 2'-(5-dimethyl-aminonaphthalene-1-sulfonyl) amino-2'-deoxyATP, with E. coli F1-ATPase and its subunits: the roles of the high affinity binding site in the alpha subunit and the low affinity binding site in the beta subunit.

    Science.gov (United States)

    Matsuoka, I; Takeda, K; Futai, M; Tonomura, Y

    1982-11-01

    We performed kinetic studies on the reactions of a fluorescent ATP analog, 2'-(5-dimethyl-aminonaphthalene-1-sulfonyl) amino-2'-deoxyATP (DNS-ATP), with E. coli F1-ATPase (EF1) and its subunits, to clarify the role of each subunit in the ATPase reaction. The following results were obtained. 1. One mol of EF1, which contains nonexchangeable 2 mol ATP and 0.5 mol ADP, binds 3 mol of DNS-ATP. The apparent dissociation constant, in the presence of Mg2+, was 0.23 microM. Upon binding, the fluorescence intensity of DNS-ATP at 520 nm increased exponentially with t1/2 of 35 s, and reached 3.5 times the original fluorescence level. Following the fluorescence increase, DNS-ATP was hydrolyzed, and the fluorescence intensity maintained its enhanced level. 2. The addition of an excess of ATP over the EF1-DNS-nucleotide complex, in the presence of Mg2+, decreased the fluorescence intensity rapidly, indicating the acceleration of DNS-nucleotide release from EF1. ADP and GTP also decreased the fluorescence intensity. 3. DCCD markedly inhibited the accelerating effect of ATP on DNS-nucleotide release from EF1 and the EF1-DNS-ATPase or -ATPase activity in a steady state. On the other hand, DCCD only slightly inhibited the fluorescence increase of DNS-ATP, due to its binding to EF1, and the rate of single cleavage of 1 mol of DNS-ATP per mol of alpha subunit of EF1. 4. In the presence of Mg2+, 0.65-0.82 mol of DNS-ATP binds to 1 mol of the isolated alpha subunit of EF1 with an apparent dissociation constant of 0.06-0.07 microM. Upon binding, the fluorescence intensity of DNS-ATP at 520 nm increased 1.55 fold very rapidly (t1/2 less than 1 s). No hydrolysis of DNS-ATP was observed upon the addition of the isolated alpha subunit. The fluorescence intensity of DNS-ATP was unaffected by the addition of the isolated beta subunit. DNS-ATP was also unhydrolyzed by the isolated beta subunit. 5. EF1-ATPase was reconstituted from alpha, beta, and gamma subunits in the presence of Mg2+ and ATP

  13. daf-31 encodes the catalytic subunit of N alpha-acetyltransferase that regulates Caenorhabditis elegans development, metabolism and adult lifespan.

    Science.gov (United States)

    Chen, Di; Zhang, Jiuli; Minnerly, Justin; Kaul, Tiffany; Riddle, Donald L; Jia, Kailiang

    2014-10-01

    The Caenorhabditis elegans dauer larva is a facultative state of diapause. Mutations affecting dauer signal transduction and morphogenesis have been reported. Of these, most that result in constitutive formation of dauer larvae are temperature-sensitive (ts). The daf-31 mutant was isolated in genetic screens looking for novel and underrepresented classes of mutants that form dauer and dauer-like larvae non-conditionally. Dauer-like larvae are arrested in development and have some, but not all, of the normal dauer characteristics. We show here that daf-31 mutants form dauer-like larvae under starvation conditions but are sensitive to SDS treatment. Moreover, metabolism is shifted to fat accumulation in daf-31 mutants. We cloned the daf-31 gene and it encodes an ortholog of the arrest-defective-1 protein (ARD1) that is the catalytic subunit of the major N alpha-acetyltransferase (NatA). A daf-31 promoter::GFP reporter gene indicates daf-31 is expressed in multiple tissues including neurons, pharynx, intestine and hypodermal cells. Interestingly, overexpression of daf-31 enhances the longevity phenotype of daf-2 mutants, which is dependent on the forkhead transcription factor (FOXO) DAF-16. We demonstrate that overexpression of daf-31 stimulates the transcriptional activity of DAF-16 without influencing its subcellular localization. These data reveal an essential role of NatA in controlling C. elegans life history and also a novel interaction between ARD1 and FOXO transcription factors, which may contribute to understanding the function of ARD1 in mammals.

  14. Genetic Construction of Truncated and Chimeric Metalloproteins Derived from the Alpha Subunit of Acetyl-CoA Synthase from Clostridium thermoaceticum

    Energy Technology Data Exchange (ETDEWEB)

    Huay-Keng Loke; Xiangshi Tan; Paul A. Lindahl

    2002-06-28

    In this study, a genetics-based method is used to truncate acetyl-coenzyme A synthase from Clostridium thermoaceticum (ACS), an alpha2beta2 tetrameric 310 kda bifunctional enzyme. ACS catalyzes the reversible reduction of CO2 to CO and the synthesis of acetyl-CoA from CO (or CO2 in the presence of low-potential reductants), CoA, and a methyl group bound to a corrinoid-iron sulfur protein (CoFeSP). ACS contains 7 metal-sulfur clusters of 4 different types called A, B, C, and D. The B, C, and D clusters are located in the 72 kda beta subunit while the A-cluster, a Ni-X-Fe4S4 cluster that serves as the active site for acetyl-CoA synthase activity, is located in the 82 kda alpha subunit. The extent to which the essential properties of the cluster, including catalytic, redox, spectroscopic, and substrate-binding properties, were retained as ACS was progressively truncated was determined. Acetyl-CoA synthase catalytic activity remained when the entire alpha subunit was removed, as long as CO, rather than CO2 and a low-potential reductant, was used as a substrate. Truncating an {approx} 30 kda region from the N-terminus of the alpha subunit yielded a 49 kda protein that lacked catalytic activity but exhibited A-cluster-like spectroscopic, redox, and CO binding properties. Further truncation afforded a 23 kda protein that lacked recognizable A-cluster properties except for UV-vis spectra typical of [Fe4S4]2+ clusters. Two chimeric proteins were constructed by fusing the gene encoding a ferredoxin from Chromatium vinosum to genes encoding the 49 kda and 82 kda fragments of the alpha subunit. The chimeric proteins exhibited EPR signals that were not the simple sum of the signals from the separate proteins, suggesting magnetic interactions between clusters. This study highlights the potential for using genetics to simplify the study of complex multi-centered metalloenzymes and to generate new complex metalloenzymes with interesting properties.

  15. Genetic Construction of Truncated and Chimeric Metalloproteins Derived from the Alpha Subunit of Acetyl-CoA Synthase from Clostridium thermoaceticum

    Energy Technology Data Exchange (ETDEWEB)

    Huay-Keng Loke; Xiangshi Tan; Paul A. Lindahl

    2002-06-28

    In this study, a genetics-based method is used to truncate acetyl-coenzyme A synthase from Clostridium thermoaceticum (ACS), an alpha2beta2 tetrameric 310 kda bifunctional enzyme. ACS catalyzes the reversible reduction of CO2 to CO and the synthesis of acetyl-CoA from CO (or CO2 in the presence of low-potential reductants), CoA, and a methyl group bound to a corrinoid-iron sulfur protein (CoFeSP). ACS contains 7 metal-sulfur clusters of 4 different types called A, B, C, and D. The B, C, and D clusters are located in the 72 kda beta subunit while the A-cluster, a Ni-X-Fe4S4 cluster that serves as the active site for acetyl-CoA synthase activity, is located in the 82 kda alpha subunit. The extent to which the essential properties of the cluster, including catalytic, redox, spectroscopic, and substrate-binding properties, were retained as ACS was progressively truncated was determined. Acetyl-CoA synthase catalytic activity remained when the entire alpha subunit was removed, as long as CO, rather than CO2 and a low-potential reductant, was used as a substrate. Truncating an {approx} 30 kda region from the N-terminus of the alpha subunit yielded a 49 kda protein that lacked catalytic activity but exhibited A-cluster-like spectroscopic, redox, and CO binding properties. Further truncation afforded a 23 kda protein that lacked recognizable A-cluster properties except for UV-vis spectra typical of [Fe4S4]2+ clusters. Two chimeric proteins were constructed by fusing the gene encoding a ferredoxin from Chromatium vinosum to genes encoding the 49 kda and 82 kda fragments of the alpha subunit. The chimeric proteins exhibited EPR signals that were not the simple sum of the signals from the separate proteins, suggesting magnetic interactions between clusters. This study highlights the potential for using genetics to simplify the study of complex multi-centered metalloenzymes and to generate new complex metalloenzymes with interesting properties.

  16. Mapping of the {alpha}{sub 4} subunit gene (GABRA4) to human chromosome 4 defines an {alpha}{sub 2}-{alpha}{sub 4}-{beta}{sub 1}-{gamma}{sub 1} gene cluster: Further evidence that modern GABA{sub a} receptor gene clusters are derived from an ancestral cluster

    Energy Technology Data Exchange (ETDEWEB)

    McLean, P.J.; Farb, D.H.; Russek, S.J. [Boston Univ. School of Medicine, MA (United States)] [and others

    1995-04-10

    We demonstrated previously that an {alpha}{sub 1}-{beta}{sub 2}-{gamma}{sub 2} gene cluster of the {gamma}-aminobutyric acid (GABA{sub A}) receptor is located on human chromosome 5q34-q35 and that an ancestral {alpha}-{beta}-{gamma} gene cluster probably spawned clusters on chromosomes 4, 5, and 15. Here, we report that the {alpha}{sub 4} gene (GABRA4) maps to human chromosome 4p14-q12, defining a cluster comprising the {alpha}{sub 2}, {alpha}{sub 4}, {beta}{sub 1}, and {gamma}{sub 1} genes. The existence of an {alpha}{sub 2}-{alpha}{sub 4}-{beta}{sub 1}-{gamma}{sub 2} cluster on chromosome 4 and an {alpha}{sub 1}-{alpha}{sub 6}-{beta}{sub 2}-{gamma}{sub 2} cluster on chromosome 5 provides further evidence that the number of ancestral GABA{sub A} receptor subunit genes has been expanded by duplication within an ancestral gene cluster. Moreover, if duplication of the {alpha} gene occurred before duplication of the ancestral gene cluster, then a heretofore undiscovered subtype of a subunit should be located on human chromosome 15q11-q13 within an {alpha}{sub 5}-{alpha}{sub x}-{beta}{sub 3}-{gamma}{sub 3} gene cluster at the locus for Angelman and Prader-Willi syndromes. 34 refs., 6 figs., 1 tab.

  17. Effects of estradiol-17beta administration on steady-state messenger ribonucleic acid (MRNA) encoding equine alpha and LH/CGbeta subunits in pituitaries of ovariectomized pony mares.

    Science.gov (United States)

    Sharp, D C; Wolfe, M W; Cleaver, B D; Nilson, J

    2001-03-15

    The process of sexual recrudescence in the springtime in mares is characterized by renewal of follicular growth and acquisition of steroidogenic competence. Concomitant with renewal of follicular steroidogenesis is re-establishment of LH biosynthesis and secretion. Research results from our laboratory indicate that increased estradiol and LH secretion occur in close temporal association before the first ovulation of the year. Therefore, the hypothesis tested in this experiment was that estrogen administration to ovariectomized pony mares during the equivalent time of early vernal transition would enhance LH biosynthesis as monitored by messenger ribonucleic acid (mRNA) encoding for the pituitary subunits of LH (alpha and LH/CGbeta). Mares were administered either sesame oil vehicle control, or estradiol (5 mg i.m. twice daily in sesame oil) for 3, 6 or 9 days, beginning on February 2. The pituitary glands were harvested, and examined for LH subunit mRNA by Northern Blot and slot blot analysis. There was a significant increase in LH secretion after 6 days of estradiol secretion compared with control vehicle administration. Similarly, there was a significant increase in both alpha and LH/CGbeta subunit mRNA when estradiol was administered for 9 days. These data indicate that estrogen stimulates LH subunit formation in mares during early equivalent vernal transition. These data do not, however, discriminate between a direct pituitary effect of estrogen, and a hypothalamic effect. Whether the surge of estradiol just prior to the first ovulation of the year is essential for the renewed biosynthesis of LH subunits cannot be determined from these data. However an important role of estrogen in the final stages of sexual recrudescence is indicated.

  18. A Trp474Cys mutation in the alpha-subunit of beta-hexosaminidase causes a subacute encephalopathic form of G{sub M2} gangliosidosis, type 1

    Energy Technology Data Exchange (ETDEWEB)

    Petroulakis, E.; Cao, Z.; Salo, T. [Univ. of Manitoba, Winnipeg (Canada)] [and others

    1994-09-01

    Mutations in the HEXA gene that encodes the {alpha}-subunit of the heterodimeric lysosomal enzyme {beta}-hexosaminidase A, or Hex A ({alpha}{beta}), cause G{sub M2} gangliosidosis, type 1. The infantile form (Tay-Sachs disease) results when there is no residual Hex A activity, while less severe and more variable clinical phenotypes result when residual Hex A activity is present. A non-Jewish male who presented with an acute psychotic episode at age 16 was diagnosed with a subacute encephalopathic form of G{sub M2} gangliosidosis. At age 19, chronic psychosis with intermittent acute exacerbations remains the most disabling symptom in this patient and his affected brother although both exhibit some ataxia and moderately severe dysarthria. We have found a 4 bp insertion (+TATC 1278) associated with infantile Tay-Sachs disease on one allele; no previously identified mutation was found on the second allele. SSCP analysis detected a shift in exon 13 and sequencing revealed a G1422C mutation in the second allele that results in a Trp474Cys substitution. The presence of the mutation was confirmed by the loss of HaeIII and ScrFI sites in exon 13 PCR products from the subjects and their father. The mutation was introduced into the {alpha}-subunit cDNA and Hex S ({alpha}{alpha}) and Hex A ({alpha}{beta}) were transiently expressed in monkey COS-7 cells. The Trp474Cys mutant protein had approximately 5% and 12% of wild-type Hex S and Hex A activity, respectively. Western blot analysis revealed a small amount of residual mature {alpha}-subunit and a normal level of precursor protein. We conclude that the Trp474Cys mutation is the cause of the Hex A deficiency associated with a subacute (juvenile-onset) phenotype in this patient. Like other mutations in exon 13 of HEXA, it appears to affect intracellular processing. Studies of the defect in intracellular processing are in progress.

  19. Identification of the minimal copper(II)-binding alpha-synuclein sequence.

    Science.gov (United States)

    Jackson, Mark S; Lee, Jennifer C

    2009-10-05

    Parkinson's disease has been long linked to environmental factors, such as transition metals and recently to alpha-synuclein, a presynaptic protein. Using tryptophan-containing peptides, we identified the minimal Cu(II)-binding sequence to be within the first four residues, MDV(F/W), anchored by the alpha-amino terminus. In addition, mutant peptide 1-10 (Lys --> Arg) verified that neither Lys6 nor Lys10 are necessary for Cu(II) binding. Interestingly, Trp4 excited-state decay kinetics measured for peptides and proteins reveal two quenching modes, possibly arising from two distinct Cu(II)-polypeptide structures.

  20. Interleukin-2 and subunit alpha of its soluble receptor in autoimmune Addison's disease--an association study and expression analysis.

    Science.gov (United States)

    Fichna, Marta; Żurawek, Magdalena; Bratland, Eirik; Husebye, Eystein S; Kasperlik-Załuska, Anna; Czarnocka, Barbara; Januszkiewicz-Lewandowska, Danuta; Nowak, Jerzy

    2015-03-01

    Autoimmune Addison's disease (AAD) results from T cell-mediated destruction of the adrenal cortex, commonly accompanied by autoantibodies to 21-hydroxylase (21OH). In order to gain insight into the obscure aetiology of this disease, we investigated the roles of the IL2 and IL2RA genes, encoding interleukin-2 and subunit alpha of its receptor (IL2Ra), respectively. The association of AAD with IL2 and IL2RA polymorphisms (rs6822844, rs2069762, rs3136534, rs11594656, rs3118470 and rs2104286) was tested in 223 patients and 672 healthy controls. Functional studies consisted of gene expression analysis in cultured PBMCs exposed to 21OH and evaluation of serum interleukin by ELISA assays. The frequency of the minor C allele of rs3136534 was significantly decreased in AAD subjects compared to controls (OR 0.71; 95%CI 0.561-0.887; p = 0.003). Only AAD cells responded to 21OH with an elevated IL2 and IL2RA mRNA synthesis (p = 0.004 and p = 0.009 versus controls, respectively), paralleled by increased supernatant levels of both cytokines (p = 0.031 and p = 0.001 versus controls). IL2 mRNA level in 21OH-stimulated AAD PBMCs correlated negatively with age (p = 0.036) and positively with serum antibodies to 21OH (p = 0.006). Carriers of the rs2104286 AA genotype demonstrated higher IL2RA mRNA (p = 0.022) and soluble IL2Ra secretion (p = 0.029) upon 21OH stimulation. Serum interleukin-2 in AAD subjects was significantly higher compared to controls (4.61 ± 4.3 versus 1.71 ± 3.2 pg/mL, p < 0.001), whereas sIL2Ra levels remained similar in both groups (p = 0.885). In conclusion, the study reveals an association between AAD and IL2 locus. It confirms specific 21OH-directed reactivity of the peripheral AAD lymphocytes, which display increased synthesis of interleukin-2 and sIL2Ra.

  1. Interaction between obesity and the Hypoxia Inducible Factor 3 Alpha Subunit rs3826795 polymorphism in relation with plasma alanine aminotransferase.

    Science.gov (United States)

    Wang, Shuo; Song, Jieyun; Yang, Yide; Zhang, Yining; Chawla, Nitesh V; Ma, Jun; Wang, Haijun

    2017-07-28

    Hypoxia Inducible Factor 3 Alpha Subunit (HIF3A) DNA has been demonstrated to be associated with obesity in the methylation level, and it also has a Body Mass Index (BMI)-independent association with plasma alanine aminotransferase (ALT). However, the relation among obesity, plasma ALT, HIF3A polymorphism and methylation remains unclear. This study aims to identify the association between HIF3A polymorphism and plasma ALT, and further to determine whether the effect of HIF3A polymorphism on ALT could be modified by obesity or mediated by DNA methylation. The HIF3A rs3826795 polymorphism was genotyped in a case-control study including 2030 Chinese children aged 7-18 years (705 obese cases and 1325 non-obese controls). Furthermore, the HIF3A DNA methylation of the peripheral blood was measured in 110 severely obese children and 110 age- and gender- matched normal-weight controls. There was no overall association between the HIF3A rs3826795 polymorphism and ALT. A significant interaction between obesity and rs3826795 in relation with ALT was found (P inter = 0.042), with rs3826795 G-allele number elevating ALT significantly only in obese children (β' = 0.075, P = 0.037), but not in non-obese children (β' = -0.009, P = 0.741). Additionally, a mediation effect of HIF3A methylation was found in the association between the HIF3A rs3826795 polymorphism and ALT among obese children (β' = 0.242, P = 0.014). This is the first study to report the interaction between obesity and HIF3A gene in relation with ALT, and also to reveal a mediation effect among the HIF3A polymorphism, methylation and ALT. This study provides new evidence to the function of HIF3A gene, which would be helpful for future risk assessment and personalized treatment of liver diseases.

  2. Involvement of proteasome alpha-subunit PSMA7 in hepatitis C virus internal ribosome entry site-mediated translation.

    Science.gov (United States)

    Krüger, M; Beger, C; Welch, P J; Barber, J R; Manns, M P; Wong-Staal, F

    2001-12-01

    Ribozymes are small catalytic RNA molecules that can be engineered to enzymatically cleave RNA transcripts in a sequence-specific fashion and thereby inhibit expression and function of the corresponding gene product. With their simple structures and site-specific cleavage activity, they have been exploited as potential therapeutic agents in a variety of human disorders, including hepatitis C virus (HCV) infection. We have designed a hairpin ribozyme (Rz3'X) targeting the HCV minus-strand replication intermediate at position 40 within the 3'X tail. Surprisingly, Rz3'X was found to induce ganciclovir (GCV)-resistant colonies in a bicistronic cellular reporter system with HCV internal ribosome entry site (IRES)-dependent translation of herpes simplex virus thymidine kinase (TK). Rz3'X-transduced GCV-resistant HeLa reporter cells showed substantially reduced IRES-mediated HCV core protein translation compared with control vector-transduced cells. Since these reporter systems do not contain the HCV 3'X tail sequences, the results indicate that Rz3'X probably exerted an inhibitory effect on HCV IRES activity fortuitously through another gene target. A novel technique of ribozyme cleavage-based target gene identification (cleavage-specific amplification of cDNA ends) (M. Krüger, C. Beger, P. J. Welch, J. R. Barber, and F. Wong-Staal, Nucleic Acids Res. 29:e94, 2001) revealed that human 20S proteasome alpha-subunit PSMA7 mRNA was a target RNA recognized and cleaved by Rz3'X. We then showed that additional ribozymes directed against PSMA7 RNA inhibited HCV IRES activity in two assay systems: GCV resistance in the HeLa IRES TK reporter cell system and a transient transfection assay performed with a bicistronic Renilla-HCV IRES-firefly luciferase reporter in Huh7 cells. In contrast, ribozymes were inactive against IRES of encephalomyocarditis virus and human rhinovirus. Additionally, proteasome inhibitor MG132 exerted a dose-dependent inhibitory effect on HCV IRES

  3. Determination of palladium(II) with alpha-(2-benzimidazolyl)-alpha',alpha''-(N-5-nitro-2-pyridylhydrazone)-toluene by adsorptive cathodic stripping voltammetry.

    Science.gov (United States)

    Kim, Sung-Ii; Cha, Ki-Won

    2002-06-10

    The determination of palladium(II) complexed with alpha-(2-benzimidazolyl)-alpha',alpha''-(N-5-nitro-2-pyridylhydrazone)-Toluene (BINPHT) was investigated by adsorptive cathodic stripping voltammetry using hanging mercury drop electrode. Palladium(II) in the sample solution can be determined in BINPHT and ethylenediaminetetraacetic acid (EDTA). Accumulation is achieved by adsorption of Pd(II)-BINPHT complex on a hanging mercury drop electrode. Optimal conditions were found to be: supporting electrolyte; 0.01 M sodium acetate buffer at pH 5.0, accumulation potential; -590 mV versus Ag/AgCl, accumulation time; 180 s, scan rate; 50 mV s(-1), concentration of BINPHT; 2x10(-5) M. The linear range of Pd(II) was observed over the concentration range 20-100 ng ml(-1) The detection limit (S/N=3) is 2 ng ml(-1). A good reproductivity shows RSD of 2.0% (n=7). This procedure offers high selectivity with the presence of EDTA masking some metallic ions. River water sample spiking with palladium was determined.

  4. Protein kinase CK2: evidence for a protein kinase CK2beta subunit fraction, devoid of the catalytic CK2alpha subunit, in mouse brain and testicles

    DEFF Research Database (Denmark)

    Guerra, B; Siemer, S; Boldyreff, B

    1999-01-01

    signals were observed for lung, liver and testicles. In the case of CK2beta mRNA the highest signals were found for testicles, kidney, brain and liver. The amount of CK2beta mRNA in testicles was estimated to be about 6-fold higher than in brain. The strongest CK2beta signals in the Western blot were...... in brain and testicles. By contrast, Northern blot analyses of the CK2alpha mRNA revealed a somewhat different picture. Here, the strongest signals were obtained for brain, liver, heart and lung. In kidney, spleen and testicles mRNAs were only weakly detectable. For CK2alpha' mRNA distribution strong...

  5. The host-dependent interaction of alpha-importins with influenza PB2 polymerase subunit is required for virus RNA replication.

    Directory of Open Access Journals (Sweden)

    Patricia Resa-Infante

    Full Text Available The influenza virus polymerase is formed by the PB1, PB2 and PA subunits and is required for virus transcription and replication in the nucleus of infected cells. As PB2 is a relevant host-range determinant we expressed a TAP-tagged PB2 in human cells and isolated intracellular complexes. Alpha-importin was identified as a PB2-associated factor by proteomic analyses. To study the relevance of this interaction for virus replication we mutated the PB2 NLS and analysed the phenotype of mutant subunits, polymerase complexes and RNPs. While mutant PB2 proteins showed reduced nuclear accumulation, they formed polymerase complexes normally when co expressed with PB1 and PA. However, mutant RNPs generated with a viral CAT replicon showed up to hundred-fold reduced CAT accumulation. Rescue of nuclear localisation of mutant PB2 by insertion of an additional SV40 TAg-derived NLS did not revert the mutant phenotype of RNPs. Furthermore, determination of recombinant RNP accumulation in vivo indicated that PB2 NLS mutations drastically reduced virus RNA replication. These results indicate that, above and beyond its role in nuclear accumulation, PB2 interaction with alpha-importins is required for virus RNA replication. To ascertain whether PB2-alpha-importin binding could contribute to the adaptation of H5N1 avian viruses to man, their association in vivo was determined. Human alpha importin isoforms associated efficiently to PB2 protein of an H3N2 human virus but bound to diminished and variable extents to PB2 from H5N1 avian or human strains, suggesting that the function of alpha importin during RNA replication is important for the adaptation of avian viruses to the human host.

  6. Tanshinone II-A sodium sulfonate (DS-201) enhances human BKCa channel activity by selectively targeting the pore-forming α subunit.

    Science.gov (United States)

    Tan, Xiao-qiu; Cheng, Xiu-li; Yang, Yan; Yan, Li; Gu, Jing-li; Li, Hui; Zeng, Xiao-rong; Cao, Ji-min

    2014-11-01

    Tanshinone II-A sodium sulfonate (DS-201), a water-soluble derivative of Tanshinone II-A, has been found to induce vascular relaxation and activate BKCa channels. The aim of this study was to explore the mechanisms underlying the action of DS-201 on BKCa channels. Human BKCa channels containing α subunit alone or α plus β1 subunits were expressed in HEK293 cells. BKCa currents were recorded from the cells using patch-clamp technique. The expression and trafficking of BKCa subunits in HEK293 cells or vascular smooth muscle cells (VSMCs) were detected by Western blotting, flow cytometry and confocal microscopy. DS-201 (40-160 μmol/L) concentration-dependently increased the total open probability of BKCa channels in HEK293 cells, associated with enhancements of Ca(2+) and voltage dependence as well as a delay in deactivation. Coexpression of β1 subunit did not affect the action of DS-201: the values of EC50 for BKCa channels containing α subunit alone and α plus β1 subunit were 66.6±1.5 and 62.0±1.1 μmol/L, respectively. In both HEK293 cells and VSMCs, DS-201 (80 μmol/L) markedly increased the expression of α subunit without affecting β1 subunit. In HEK293 cells, DS-201 enriched the membranous level of α subunit, likely by accelerating the trafficking and suppressing the internalization of α subunit. In both HEK293 cells and VSMCs, DS-201 (≥320 μmol/L) induced significant cytotoxicity. DS-201 selectively targets the pore-forming α subunit of human BKCa channels, thus enhancing the channel activities and increasing the subunit expression and trafficking, whereas the β1 subunit does not contribute to the action of DS-201.

  7. Co-expression of alpha7 and beta2 nicotinic acetylcholine receptor subunit mRNAs within rat brain cholinergic neurons.

    Science.gov (United States)

    Azam, L; Winzer-Serhan, U; Leslie, F M

    2003-01-01

    Nicotine enhances cognitive and attentional processes through stimulation of the basal forebrain cholinergic system. Although muscarinic cholinergic autoreceptors have been well characterized, pharmacological characterization of nicotinic autoreceptors has proven more difficult. The present study used double-labeling in situ hybridization to determine expression of nicotinic acetylcholine receptor (nAChR) subunit mRNAs within basal forebrain cholinergic neurons in order to gain information about possible nAChR autoreceptor properties. Cholinergic cells of the mesopontine tegmentum and striatal interneurons were also examined, as were septohippocampal GABAergic neurons that interact with cholinergic neurons to regulate hippocampal activity. alpha7 and beta2 nAChR mRNAs were found to be co-expressed in almost all cholinergic cells and in the majority of GABAergic neurons examined. alpha4 nAChR mRNA expression was restricted to cholinergic cells of the nucleus basalis magnocellularis, and to non-cholinergic cells of the medial septum and mesopontine tegmentum. These data suggest possible regional differences in the pharmacological properties of nicotinic autoreceptors on cholinergic cells. Whereas most cholinergic cells express rapidly desensitizing alpha7 homomers or alpha7beta2 heteromers, cortical projection neurons may also express a pharmacologically distinct alpha4beta2 nAChR subtype. There may also be differential nAChR regulation of cholinergic and non-cholinergic cells within the mesopontine tegmentum that are implicated in acquisition of nicotine self-administration.

  8. Top-down proteomic identification of furin-cleaved alpha-subunit of Shiga toxin 2 from Escherichia coli O157:H7 using MALDI-TOF-TOF-MS/MS

    Science.gov (United States)

    A method has been developed to identify the alpha-subunit of shiga toxin 2 (alpha-Stx2) from Escherichia coli O157:H7 using matrix-assisted laser desorption/ionization time-of-flight-time-of-flight tandem mass spectrometry (MALDI-TOF-TOF-MS/MS) and top-down proteomics using web-based software develo...

  9. Reduction of mouse egg surface integrin alpha9 subunit (ITGA9) reduces the egg's ability to support sperm-egg binding and fusion.

    Science.gov (United States)

    Vjugina, Ulyana; Zhu, Xiaoling; Oh, Eugene; Bracero, Nabal J; Evans, Janice P

    2009-04-01

    The involvement of egg integrins in mammalian sperm-egg interactions has been controversial, with data from integrin inhibitor studies contrasting with evidence from knockouts showing that specific integrin subunits are not essential for fertility. An alpha(4)/alpha(9) (ITGA4/ITGA9) integrin subfamily member has been implicated in fertilization but not extensively examined, so we tested the following three hypotheses: 1) an ITGA4/ITGA9 integrin participates in sperm-egg interactions, 2) short-term acute knockdown by RNA interference of integrin subunits would result in a fertilization phenotype differing from that of chronic depletion via knockout, and 3) detection of a fertilization phenotype is sensitive to in vitro fertilization (IVF) assay conditions. We show that mouse and human eggs express the alpha(9) integrin subunit (ITGA9). RNA interference-mediated knockdown resulted in reduced levels of Itga9 mRNA and surface protein in mouse eggs. RNA interference attempts to knockdown ITGA9's likely beta partner, beta(1) (ITGB1), resulted in reduced Itgb1 mRNA but no reduction in ITGB1 surface protein. Therefore, studies using a function-blocking anti-ITGB1 antibody tested the hypothesis that ITGB1 participates in gamete interactions. Analyses of sperm-egg interactions with Itga9-knockdown eggs and anti-ITGB1 antibody-treated eggs in IVF assays using specific sperm:egg ratios revealed the following: 1) a reduction, but not complete loss, of sperm-egg binding and fusion was observed and 2) the reduction of sperm-egg binding and fusion was not detected in inseminations with high sperm:egg ratios. These data demonstrate that ITGA9 and ITGB1 participate in sperm-egg interactions but clearly are not the only molecules involved. This also shows that careful design of IVF parameters allows detection of deficiencies in gamete interactions.

  10. Improving Saccharomyces cerevisiae ethanol production and tolerance via RNA polymerase II subunit Rpb7

    National Research Council Canada - National Science Library

    Zilong Qiu; Rongrong Jiang

    2017-01-01

    .... Here we try to improve Saccharomyces cerevisiae ethanol tolerance and productivity by reprogramming its transcription profile through rewiring its key transcription component RNA polymerase II (RNAP II...

  11. Effects of cigarette smoke exposure on nicotinic acetylcholine receptor subunits {alpha}7 and {beta}2 in the sudden infant death syndrome (SIDS) brainstem

    Energy Technology Data Exchange (ETDEWEB)

    Machaalani, Rita, E-mail: rita.machaalani@sydney.edu.au [Department of Medicine, The University of Sydney, NSW 2006 (Australia); Bosch Institute, The University of Sydney, NSW 2006 (Australia); The Children' s Hospital at Westmead, NSW 2145 (Australia); Say, Meichien [Department of Medicine, The University of Sydney, NSW 2006 (Australia); Bosch Institute, The University of Sydney, NSW 2006 (Australia); Waters, Karen A. [Department of Medicine, The University of Sydney, NSW 2006 (Australia); Bosch Institute, The University of Sydney, NSW 2006 (Australia); The Children' s Hospital at Westmead, NSW 2145 (Australia)

    2011-12-15

    It is postulated that nicotine, as the main neurotoxic constituent of cigarette smoke, influences SIDS risk through effects on nicotinic acetylcholine receptors (nAChRs) in brainstem nuclei that control respiration and arousal. This study compared {alpha}7 and {beta}2 nAChR subunit expression in eight nuclei of the caudal and rostral medulla and seven nuclei of the pons between SIDS (n = 46) and non-SIDS infants (n = 14). Evaluation for associations with known SIDS risk factors included comparison according to whether infants had a history of exposure to cigarette smoke in the home, and stratification for sleep position and gender. Compared to non-SIDS infants, SIDS infants had significantly decreased {alpha}7 in the caudal nucleus of the solitary tract (cNTS), gracile and cuneate nuclei, with decreased {beta}2 in the cNTS and increased {beta}2 in the facial. When considering only the SIDS cohort: 1-cigarette smoke exposure was associated with increased {alpha}7 in the vestibular nucleus and increased {beta}2 in the rostral dorsal motor nucleus of the vagus, rNTS and Cuneate, 2-there was a gender interaction for {alpha}7 in the gracile and cuneate, and {beta}2 in the cNTS and rostral arcuate nucleus, and 3-there was no effect of sleep position on {alpha}7, but prone sleep was associated with decreased {beta}2 in three nuclei of the pons. In conclusion, SIDS infants demonstrate differences in expression of {alpha}7 and {beta}2 nAChRs within brainstem nuclei that control respiration and arousal, which is independent on prior history of cigarette smoke exposure, especially for the NTS, with additional differences for smoke exposure ({beta}2), gender ({alpha}7 and {beta}2) and sleep position ({beta}2) evident. -- Highlights: Black-Right-Pointing-Pointer The 'normal' response to smoke exposure is decreased {alpha}7 and {beta}2 in certain nuclei. Black-Right-Pointing-Pointer SIDS infants have decreased {alpha}7 in cNTS, Grac and Cun. Black

  12. Attenuation of the slow component of delayed rectification, action potential prolongation, and triggered activity in mice expressing a dominant-negative Kv2 alpha subunit.

    Science.gov (United States)

    Xu, H; Barry, D M; Li, H; Brunet, S; Guo, W; Nerbonne, J M

    1999-10-01

    An in vivo experimental strategy, involving cardiac-specific expression of a mutant Kv 2.1 subunit that functions as a dominant negative, was exploited in studies focused on exploring the role of members of the Kv2 subfamily of pore-forming (alpha) subunits in the generation of functional voltage-gated K(+) channels in the mammalian heart. A mutant Kv2.1 alpha subunit (Kv2.1N216) was designed to produce a truncated protein containing the intracellular N terminus, the S1 membrane-spanning domain, and a portion of the S1/S2 loop. The truncated Kv2.1N216 was epitope tagged at the C terminus with the 8-amino acid FLAG peptide to generate Kv2. 1N216FLAG. No ionic currents are detected on expression of Kv2. 1N216FLAG in HEK-293 cells, although coexpression of this construct with wild-type Kv2.1 markedly reduced the amplitudes of Kv2. 1-induced currents. Using the alpha-myosin heavy chain promoter to direct cardiac specific expression of the transgene, 2 lines of Kv2. 1N216FLAG-expressing transgenic mice were generated. Electrophysiological recordings from ventricular myocytes isolated from these animals revealed that I(K, slow) is selectively reduced. The attenuation of I(K, slow) is accompanied by marked action potential prolongation, and, occasionally, spontaneous triggered activity (apparently induced by early afterdepolarizations) is observed. The time constant of inactivation of I(K, slow) in Kv2. 1N216FLAG-expressing cells (mean+/-SEM=830+/-103 ms; n=17) is accelerated compared with the time constant of I(K, slow) inactivation (mean+/-SEM=1147+/-57 ms; n=25) in nontransgenic cells. In addition, unlike I(K, slow) in wild-type cells, the component of I(K, slow) remaining in the Kv2.1N216FLAG-expressing cells is insensitive to 25 mmol/L tetraethylammonium. Taken together, these observations suggest that there are 2 distinct components of I(K, slow) in mouse ventricular myocytes and that Kv2 alpha subunits underlie the more slowly inactivating, tetraethylammonium

  13. Alpha Trianguli Australis (K2 II-III) - Hybrid or composite?

    Science.gov (United States)

    Ayres, T. R.

    1985-01-01

    The prototype hybrid-spectrum giant Alpha Trianguli Australis exhibits a far-ultraviolet continuum which is considerably bluer than would be expected of a star of its optical colors, suggesting the presence of a previously unrecognized companion. If the K-type primary is as luminous as indicated by the widths of its Ca II and H-alpha lines, the companion could be an early F-type dwarf that only recently has arrived on the main sequence. Indeed, the flux of C IV from Alpha TrA - an important measure of hybridness - would not be inconsistent with that expected from a very young chromospherically active F star.

  14. Cloning and purification of protein kinase CK2 recombinant alpha and beta subunits from the Mediterranean fly Ceratitis capitata.

    Science.gov (United States)

    Kouyanou-Koutsoukou, Sophia; Baier, Andrea; Kolaitis, Regina-Maria; Maniatopoulou, Evanthia; Thanopoulou, Konstantina; Szyszka, Ryszard

    2011-10-01

    The Mediterranean fruit fly Ceratitis capitata is an insect capable of wreaking extensive damage to a wide range of fruit crops. Protein kinase CK2 is a ubiquitous Ser/Thr kinase that is highly conserved among eukaryotes; it is a heterotetramer composed of two catalytic (α) and a dimer of regulatory (β) subunits. We present here the construction of the cDNA molecules of the CK2α and CK2β subunits from the medfly C. capitata by the 5'/3' RACE and RT-PCR methods, respectively. CcCK2α catalytic subunit presents the characteristic and conserved features of a typical protein kinase, similar to the regulatory CcCK2β subunit, that also possess the conserved features of regulatory CK2β subunits, as revealed by comparison of their predicted amino acid sequences with other eukaryotic species. The recombinant CcCK2α and CcCK2β proteins were purified by affinity chromatography to homogeneity, after overexpression in Escherichia coli. CcCK2α is capable to utilize GTP and its activity and is inhibited by polyanions and stimulated by polycations in phosphorylation assays, using purified acidic ribosomal protein P1 as a substrate.

  15. A Deep Narrowband Imaging Search for CIV and He II Emission from Ly$\\alpha$ Blobs

    CERN Document Server

    Battaia, Fabrizio Arrigoni; Hennawi, Joseph F; Prochaska, J Xavier; Matsuda, Yuichi; Yamada, Toru; Hayashino, Tomoki

    2014-01-01

    We conduct a deep narrow-band imaging survey of 13 Ly$\\alpha$ blobs (LABs) located in the SSA22 proto-cluster at z~3.1 in the CIV and HeII emission lines in an effort to constrain the physical process powering the Ly$\\alpha$ emission in LABs. Our observations probe down to unprecedented surface brightness limits of 2.1 $-$ 3.4 $\\times$ 10$^{-18}$ erg s$^{-1}$ cm$^{-2}$ arcsec$^{-2}$ per 1 arcsec$^2$ aperture (5$\\sigma$) for the HeII$\\lambda$1640 and CIV$\\lambda$1549 lines, respectively. We do not detect extended HeII and CIV emission in any of the LABs, placing strong upper limits on the HeII/Ly$\\alpha$ and CIV/Ly$\\alpha$ line ratios, of 0.11 and 0.16, for the brightest two LABs in the field. We conduct detailed photoionization modeling of the expected line ratios and find that, although our data constitute the deepest ever observations of these lines, they are still not deep enough to rule out a scenario where the Ly$\\alpha$ emission is powered by the ionizing luminosity of an obscured AGN. Our models can ac...

  16. Class II histone deacetylases are associated with VHL-independent regulation of hypoxia-inducible factor 1 alpha.

    Science.gov (United States)

    Qian, David Z; Kachhap, Sushant K; Collis, Spencer J; Verheul, Henk M W; Carducci, Michael A; Atadja, Peter; Pili, Roberto

    2006-09-01

    Hypoxia-inducible factor 1 alpha (HIF-1 alpha) plays a critical role in transcriptional gene activation involved in tumor angiogenesis. A novel class of agents, the histone deacetylase (HDAC) inhibitors, has been shown to inhibit tumor angiogenesis and HIF-1 alpha protein expression. However, the molecular mechanism responsible for this inhibition remains to be elucidated. In the current study, we investigated the molecular link between HIF-1 alpha inhibition and HDAC inhibition. Treatment of the VHL-deficient human renal cell carcinoma cell line UMRC2 with the hydroxamic HDAC inhibitor LAQ824 resulted in a dose-dependent inhibition of HIF-1 alpha protein via a VHL-independent mechanism and reduction of HIF-1 alpha transcriptional activity. HIF-1 alpha inhibition by LAQ824 was associated with HIF-1 alpha acetylation and polyubiquitination. HIF-1 alpha immunoprecipitates contained HDAC activity. Then, we tested different classes of HDAC inhibitors with diverse inhibitory activity of class I versus class II HDACs and assessed their capability of targeting HIF-1 alpha. Hydroxamic acid derivatives with known activity against both class I and class II HDACs were effective in inhibiting HIF-1 alpha at low nanomolar concentrations. In contrast, valproic acid and trapoxin were able to inhibit HIF-1 alpha only at concentrations that are effective against class II HDACs. Coimmunoprecipitation studies showed that class II HDAC4 and HDAC6 were associated with HIF-1 alpha protein. Inhibition by small interfering RNA of HDAC4 and HDAC6 reduced HIF-1 alpha protein expression and transcriptional activity. Taken together, these results suggest that class II HDACs are associated with HIF-1 alpha stability and provide a rationale for targeting HIF-1 alpha with HDAC inhibitors against class II isozymes.

  17. Antagonism of ligand-gated ion channel receptors: two domains of the glycine receptor alpha subunit form the strychnine-binding site.

    Science.gov (United States)

    Vandenberg, R J; French, C R; Barry, P H; Shine, J; Schofield, P R

    1992-01-01

    The inhibitory glycine receptor (GlyR) is a member of the ligand-gated ion channel receptor superfamily. Glycine activation of the receptor is antagonized by the convulsant alkaloid strychnine. Using in vitro mutagenesis and functional analysis of the cDNA encoding the alpha 1 subunit of the human GlyR, we have identified several amino acid residues that form the strychnine-binding site. These residues were identified by transient expression of mutated cDNAs in mammalian (293) cells and examination of resultant [3H]strychnine binding, glycine displacement of [3H]strychnine, and electrophysiological responses to the application of glycine and strychnine. This mutational analysis revealed that residues from two separate domains within the alpha 1 subunit form the binding site for the antagonist strychnine. The first domain includes the amino acid residues Gly-160 and Tyr-161, and the second domain includes the residues Lys-200 and Tyr-202. These results, combined with analyses of other ligand-gated ion channel receptors, suggest a conserved tertiary structure and a common mechanism for antagonism in this receptor superfamily. PMID:1311851

  18. Downstream targets of the Phytophthora infestans G alpha subunit PiGPA1 revealed by cDNA-AFLP

    NARCIS (Netherlands)

    Dong, W.; Latijnhouwers, M.; Jiang, R.H.Y.; Meijer, H.J.G.; Govers, F.

    2004-01-01

    In many plant pathogens heterotrimeric G-proteins are essential signalling components involved in development and pathogenicity. In the late blight oomycete pathogen Phytophthora infestans the G-protein (x subunit PiGPA1 controls zoospore motility and is required for virulence. To identify G-protein

  19. Copper(II) binding to alpha-synuclein, the Parkinson's protein.

    Science.gov (United States)

    Lee, Jennifer C; Gray, Harry B; Winkler, Jay R

    2008-06-04

    Variations in tryptophan fluorescence intensities confirm that copper(II) interacts with alpha-synuclein, a protein implicated in Parkinson's disease. Trp4 fluorescence decay kinetics measured for the F4W protein show that Cu(II) binds tightly (Kd 100 nM) near the N-terminus at pH 7. Work on a F4W/H50S mutant indicates that a histidine imidazole is not a ligand in this high-affinity site.

  20. Molecular evolution and nucleotide sequences of the maize plastid genes for the alpha subunit of CF1 (atpA) and the proteolipid subunit of CF0 (atpH).

    Science.gov (United States)

    Rodermel, S R; Bogorad, L

    1987-05-01

    The nucleotide sequences of the maize plastid genes for the alpha subunit of CF1 (atpA) and the proteolipid subunit of CF0 (atpH) are presented. The evolution of these genes among higher plants is characterized by a transition mutation bias of about 2:1 and by rates of synonymous and nonsynonymous substitution which are much lower than similar rates for genes from other sources. This is consistent with the notion that the plastid genome is evolving conservatively in primary sequence. Yet, the mode and tempo of sequence evolution of these and other plastid-encoded coupling factor genes are not the same. In particular, higher rates of nonsynonymous substitution in atpE (the gene for the epsilon subunit of CF1) and higher rates of synonymous substitution in atpH in the dicot vs. monocot lineages of higher plants indicate that these sequences are likely subject to different evolutionary constraints in these two lineages. The 5'- and 3'-transcribed flanking regions of atpA and atpH from maize, wheat and tobacco are conserved in size, but contain few putative regulatory elements which are conserved either in their spatial arrangement or sequence complexity. However, these regions likely contain variable numbers of "species-specific" regulatory elements. The present studies thus suggest that the plastid genome is not a passive participant in an evolutionary process governed by a more rapidly changing, readily adaptive, nuclear compartment, but that novel strategies for the coordinate expression of genes in the plastid genome may arise through rapid evolution of the flanking sequences of these genes.

  1. Ablation of phosphoinositide-3-kinase class II alpha suppresses hepatoma cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Stanley K.L. [Singapore Immunology Network A-STAR (Singapore); Neo, Soek-Ying, E-mail: neo_soek_ying@sics.a-star.edu.sg [Singapore Immunology Network A-STAR (Singapore); Yap, Yann-Wan [Singapore Immunology Network A-STAR (Singapore); Karuturi, R. Krishna Murthy; Loh, Evelyn S.L. [Genome Institute of Singapore A-STAR (Singapore); Liau, Kui-Hin [Department of General Surgery, Tan Tock Seng Hospital (Singapore); Ren, Ee-Chee, E-mail: ren_ee_chee@immunol.a-star.edu.sg [Singapore Immunology Network A-STAR (Singapore); Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore (Singapore)

    2009-09-18

    Cancer such as hepatocellular carcinoma (HCC) is characterized by complex perturbations in multiple signaling pathways, including the phosphoinositide-3-kinase (PI3K/AKT) pathways. Herein we investigated the role of PI3K catalytic isoforms, particularly class II isoforms in HCC proliferation. Among the siRNAs tested against the eight known catalytic PI3K isoforms, specific ablation of class II PI3K alpha (PIK3C2{alpha}) was the most effective in impairing cell growth and this was accompanied by concomitant decrease in PIK3C2{alpha} mRNA and protein levels. Colony formation ability of cells deficient for PIK3C2{alpha} was markedly reduced and growth arrest was associated with increased caspase 3 levels. A small but significant difference in gene dosage and expression levels was detected between tumor and non-tumor tissues in a cohort of 19 HCC patients. Taken together, these data suggest for the first time that in addition to class I PI3Ks in cancer, class II PIK3C2{alpha} can modulate HCC cell growth.

  2. Lyman Alpha and MgII as Probes of Galaxies and their Environments

    CERN Document Server

    Barnes, Luke A; Kacprzak, Glenn G

    2014-01-01

    Ly{\\alpha} emission, Ly{\\alpha} absorption and MgII absorption are powerful tracers of neutral hydrogen. Hydrogen is the most abundant element in the universe and plays a central role in galaxy formation via gas accretion and outflows, as well as being the precursor to molecular clouds, the sites of star formation. Since 21cm emission from neutral hydrogen can only be directly observed in the local universe, we rely on Ly{\\alpha} emission, and Ly{\\alpha} and MgII absorption to probe the physics that drives galaxy evolution at higher redshifts. Furthermore, these tracers are sensitive to a range of hydrogen densities that cover the interstellar medium, the circumgalactic medium and the intergalactic medium, providing an invaluable means of studying gas physics in regimes where it is poorly understood. At high redshift, Ly{\\alpha} emission line searches have discovered thousands of star-forming galaxies out to z = 7. The large Ly{\\alpha} scattering cross-section makes observations of this line sensitive to even...

  3. Prefrontal beta2 subunit-containing and alpha7 nicotinic acetylcholine receptors differentially control glutamatergic and cholinergic signaling.

    Science.gov (United States)

    Parikh, Vinay; Ji, Jinzhao; Decker, Michael W; Sarter, Martin

    2010-03-03

    One-second-long increases in prefrontal cholinergic activity ("transients") were demonstrated previously to be necessary for the incorporation of cues into ongoing cognitive processes ("cue detection"). Nicotine and, more robustly, selective agonists at alpha4beta2* nicotinic acetylcholine receptors (nAChRs) enhance cue detection and attentional performance by augmenting prefrontal cholinergic activity. The present experiments determined the role of beta2-containing and alpha7 nAChRs in the generation of prefrontal cholinergic and glutamatergic transients in vivo. Transients were evoked by nicotine, the alpha4beta2* nAChR agonist ABT-089 [2-methyl-3-(2-(S)-pyrrolindinylmethoxy) pyridine dihydrochloride], or the alpha7 nAChR agonist A-582941 [2-methyl-5-(6-phenyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole]. Transients were recorded in mice lacking beta2 or alpha7 nAChRs and in rats after removal of thalamic glutamatergic or midbrain dopaminergic inputs to prefrontal cortex. The main results indicate that stimulation of alpha4beta2* nAChRs evokes glutamate release and that the presence of thalamic afferents is necessary for the generation of cholinergic transients. ABT-089-evoked transients were completely abolished in mice lacking beta2* nAChRs. The amplitude, but not the decay rate, of nicotine-evoked transients was reduced by beta2* knock-out. Conversely, in mice lacking the alpha7 nAChR, the decay rate, but not the amplitude, of nicotine-evoked cholinergic and glutamatergic transients was attenuated. Substantiating the role of alpha7 nAChR in controlling the duration of release events, stimulation of alpha7 nAChR produced cholinergic transients that lasted 10- to 15-fold longer than those evoked by nicotine. alpha7 nAChR-evoked cholinergic transients are mediated in part by dopaminergic activity. Prefrontal alpha4beta2* nAChRs play a key role in evoking and facilitating the transient glutamatergic-cholinergic interactions that are necessary for cue detection

  4. Mitochondrial complex II participates in normoxic and hypoxic regulation of alpha-keto acids in the murine heart.

    NARCIS (Netherlands)

    Muhling, J.; Tiefenbach, M.; Lopez-Barneo, J.; Piruat, J.I.; Garcia-Flores, P.; Pfeil, U.; Gries, B.; Muhlfeld, C.; Weigand, M.A.; Kummer, W.; Weissmann, N.; Paddenberg, R.

    2010-01-01

    alpha-Keto acids (alpha-KAs) are not just metabolic intermediates but are also powerful modulators of different cellular pathways. Here, we tested the hypothesis that alpha-KA concentrations are regulated by complex II (succinate dehydrogenase=SDH), which represents an intersection between the

  5. Mitochondrial complex II participates in normoxic and hypoxic regulation of alpha-keto acids in the murine heart.

    NARCIS (Netherlands)

    Muhling, J.; Tiefenbach, M.; Lopez-Barneo, J.; Piruat, J.I.; Garcia-Flores, P.; Pfeil, U.; Gries, B.; Muhlfeld, C.; Weigand, M.A.; Kummer, W.; Weissmann, N.; Paddenberg, R.

    2010-01-01

    alpha-Keto acids (alpha-KAs) are not just metabolic intermediates but are also powerful modulators of different cellular pathways. Here, we tested the hypothesis that alpha-KA concentrations are regulated by complex II (succinate dehydrogenase=SDH), which represents an intersection between the mitoc

  6. Localization and expression of spermadhesin PSP-I/PSP-II subunits in the reproductive organs of the boar.

    Science.gov (United States)

    García, E M; Vázquez, J M; Parrilla, I; Ortega, M D; Calvete, J J; Sanz, L; Martínez, E A; Roca, J; Rodríguez-Martínez, H

    2008-08-01

    The epithelial localization and expression of the spermadhesin PSP-I and PSP-II subunits were determined in the testis, ductus epididymes (caput, corpus and cauda), seminal vesicles and bulbourethral glands of mature boars, using immunohistochemical, western blotting and RT-PCR methods. Immunohistochemistry showed positive labelling for PSP-I and PSP-II antibodies in the epithelium of seminal vesicles in all males tested. Positive immunolabelling, but with variable intensity, was also present in the epididymal epithelium (caput, corpus and cauda), although varying largely among segments and boars. Immunoreactivity was nearly or completely absent in the seminiferous epithelium and the bulbourethral gland, although SDS-PAGE and western blotting revealed the presence of PSP-I and PSP-II immunoreactive bands in all the tissue extracts, including the testis and the bulbourethral gland. mRNA amplification by RT-PCR using primers specific for PSP-I and PSP-II showed a trend similar to that observed for western blotting, i.e. intensity variation between tissues (even between segments of the same epididymis) and among boars. Our results indicate that the seminal vesicles are the main source of PSP-I and PSP-II spermadhesins, although epididymal segments, testis and the bulbourethral gland also participate in the expression of both proteins.

  7. Kinetics of prebeta1 HDL and alphaHDL in type II diabetic patients.

    Science.gov (United States)

    Chétiveaux, M; Lalanne, F; Lambert, G; Zair, Y; Ouguerram, K; Krempf, M

    2006-01-01

    The aim of this study was to analyze the recycling of high density lipoprotein (HDL) in six type II diabetic patients compared with six control subjects by endogenous labelling of apolipoprotein A-I (Apo A-I) with stable isotope Apo A. The -I-HDL kinetics were performed by infusion of (5.5.5-(2)H3)-leucine for 14 h. The prebeta1 and alphaHDL were separated by gel filtration fast protein liquid chromatrography system (FPLC). Kinetics of isotopic enrichment of Apo A-I were analyzed with a multi-compartmental model software (SAAM II, SAAM Institute, Seattle, WA). Plasma Apo A-I concentration was decreased in patients with type II diabetes as a result of a decrease in Apo A-I-alphaHDL (P Diabetic patients were also characterized by an increased relative contribution of Apo A-I in prebeta1 HDL (18.3 +/- 2.8% vs 11.9 +/- 3.7%, P HDL was slightly increased in diabetic patients compared with control (NS) and an increase of recycling rate of alpha to prebeta1 HDL was observed (11.67 +/- 3.14 d(-1) vs 7.09 +/- 4.51 d(-1), P diabetic patients (P HDL and P HDL in type II diabetic patients is mainly related to an increased conversion rate of alpha to prebeta1 HDL.

  8. Silencing gamma-aminobutyric acid A receptor alpha 1 subunit expression and outward potassium current in developing cortical neurons

    Institute of Scientific and Technical Information of China (English)

    Tao Bo; Jiang Li; Jian Li; Xingfang Li; Kaihui Xing

    2011-01-01

    We used RNA interference (RNAi) to disrupt synthesis of the cortical neuronal γ-aminobutyric acid A receptor (GABAAR) α1 in rats during development, and measured outward K+ currents during neuronal electrical activity using whole-cell patch-clamp techniques. Three pairs of small interfering RNA (siRNA) for GABAAR α1 subunit were designed using OligoEngine RNAi software. This siRNA was found to effectively inhibited GABAAR α1 mRNA expression in cortical neuronal culture in vitro, but did not significantly affect neuronal survival. Outward K+ currents were decreased, indicating that GABAAR α1 subunits in developing neurons participate in neuronal function by regulating outward K+ current.

  9. Alignment of the amino terminal amino acid sequence of human cytochrome c oxidase subunits I and II with the sequence of their putative mRNAs.

    OpenAIRE

    CHOMYN, A.; Hunkapiller, M W; Attardi, G

    1981-01-01

    Thirteen of the first fifteen amino acids from the NH2-terminus of the primary sequence of human cytochrome c oxidase subunit I and eleven of the first twelve amino acids of subunit II have been identified by microsequencing procedures. These sequences have been compared with the recently determined 5'-end proximal sequences of the HeLa cell mitochondrial mRNAs and unambiguously aligned with two of them. This alignment has allowed the identification of the putative mRNA for subunit I, and has...

  10. Complete inhibition of the tentoxin-resistant F1-ATPase from Escherichia coli by the phytopathogenic inhibitor tentoxin after substitution of critical residues in the alpha - and beta -subunit.

    Science.gov (United States)

    Schnick, Claudia; Körtgen, Nicole; Groth, Georg

    2002-12-27

    Substitution of critical residues in the alpha- and beta-subunit can turn the typically resistant ATP synthase from the bacterium Escherichia coli into an enzyme showing high sensitivity to the phytopathogenic inhibitor tentoxin, which usually affects only certain sensitive plant species. In contrast to recent results obtained with the thermophilic F(1) (Groth, G., Hisabori, T., Lill, H., and Bald, D. (2002) J. Biol. Chem. 277, 20117-20119), substitution of a critical serine in the beta-subunit (betaSer(59)), which is supposed to provide an important intermolecular hydrogen bond in the binding site, was not sufficient on its own for conferring tentoxin sensitivity to the E. coli F(1) complex. Superimposition of the chloroplast F(1)-tentoxin inhibitor complex on a homology model of the E. coli F(1) complex provided detailed information on the critical residues in the alpha-subunit of the binding cleft and allowed us to model the binding site according to the steric requirements of the inhibitor. Substitution of the highly conserved residue alphaLeu(64) seems to be most important for allowing access of the inhibitor to the binding site. Combining this substitution with either additional replacements in the alpha-subunit (Q49A, L95A, E96Q, I273M) or the replacement of Ser(59) in the beta-subunit enhanced the sensitivity to the inhibitor and resulted in a complete inhibition of the E. coli F(1)-ATPase by the plant-specific inhibitor tentoxin.

  11. Chromogranin A as serum marker for neuroendocrine neoplasia: comparison with neuron-specific enolase and the alpha-subunit of glycoprotein hormones.

    Science.gov (United States)

    Nobels, F R; Kwekkeboom, D J; Coopmans, W; Schoenmakers, C H; Lindemans, J; De Herder, W W; Krenning, E P; Bouillon, R; Lamberts, S W

    1997-08-01

    Chromogranin A (CgA) is gaining acceptance as a serum marker of neuroendocrine tumors. Its specificity in differentiating between neuroendocrine and nonneuroendocrine tumors, its sensitivity to detect small tumors, and its clinical value, compared with other neuroendocrine markers, have not clearly been defined, however. The objectives of this study were to evaluate the clinical usefulness of CgA as neuroendocrine serum marker. Serum levels of CgA, neuron-specific enolase (NSE), and the alpha-subunit of glycoprotein hormones (alpha-SU) were determined in 211 patients with neuroendocrine tumors and 180 control subjects with nonendocrine tumors. The concentrations of CgA, NSE, and alpha-SU were elevated in 50%, 43%, and 24% of patients with neuroendocrine tumors, respectively. Serum CgA was most frequently increased in subjects with gastrinomas (100%), pheochromocytomas (89%), carcinoid tumors (80%), nonfunctioning tumors of the endocrine pancreas (69%), and medullary thyroid carcinomas (50%). The highest levels were observed in subjects with carcinoid tumors. NSE was most frequently elevated in patients with small cell lung carcinoma (74%), and alpha-SU was most frequently elevated in patients with carcinoid tumors (39%). Most subjects with elevated alpha-SU levels also had elevated CgA concentrations. A significant positive relationship was demonstrated between the tumor load and serum CgA levels (P NSE, and alpha-SU were present in, respectively, 7%, 35%, and 15% of control subjects. Markedly elevated serum levels of CgA, exceeding 300 micrograms/L, were observed in only 2% of control patients (n = 3) compared to 40% of patients with neuroendocrine tumors (n = 76). We conclude that CgA is the best general neuroendocrine serum marker available. It has the highest specificity for the detection of neuroendocrine tumors compared to the other neuroendocrine markers, NSE and alpha-SU. Elevated levels are strongly correlated with tumor volume; therefore, small tumors may

  12. Autosomal dominant erythermalgia associated with a novel mutation in the voltage-gated sodium channel alpha subunit Nav1.7.

    Science.gov (United States)

    Michiels, Jan J; te Morsche, Rene H M; Jansen, Jan B M J; Drenth, Joost P H

    2005-10-01

    Autosomal dominant primary erythermalgia is a rare disorder characterized by recurrent attacks of red, warm, and painful hands and/or feet. To describe the phenotypes and molecular data of a 10-member family with 5 symptomatic living patients with erythermalgia. The clinical phenotype of this family was featured by episodic or continuous symmetrical red swelling, irritating warmth, and burning pain of feet and lower legs provoked or aggravated by warmth and exercise, and relief was always obtained by application of cold, such as putting feet in (ice-) cold water. The symptoms in this family were only partially controlled by analgesics and sedatives. All affected family members were heterozygous for a novel mutation (S241T) of the voltage-gated sodium channel alpha subunit Nav1.7. Primary erythermalgia may be a neuropathic disorder of the small peripheral sensory and sympathetic neurons, and may be caused by hyperexcitability of Nav1.7.

  13. Reduced volume and increased training intensity elevate muscle Na+/K+ pump {alpha}2-subunit expression as well as short- and long-term work capacity in humans

    DEFF Research Database (Denmark)

    Bangsbo, Jens; Gunnarsson, Thomas Petursson; Wendell, Jesper;

    2009-01-01

    The present study examined muscle adaptations and alterations in work capacity in endurance-trained runners as a result of a reduced amount of training combined with speed endurance training. Seventeen runners were for a 6- to 9-wk period assigned to either a speed endurance group with a 25......% reduction in the amount of training but including speed endurance training consisting of 6-12 30-s sprint runs 3-4 times a week (SET, n=12) or a control group (CON, n=5), which continued the endurance training (about 55 km(.)wk(-1)). For SET the expression of the muscle Na(+)/K(+) pump alpha2-subunit was 68......% higher (Ptraining period. In SET, VO2-max...

  14. Tumor necrosis factor receptor-associated protein 1 improves hypoxia-impaired energy production in cardiomyocytes through increasing activity of cytochrome c oxidase subunit II.

    Science.gov (United States)

    Xiang, Fei; Ma, Si-Yuan; Zhang, Dong-Xia; Zhang, Qiong; Huang, Yue-Sheng

    2016-10-01

    Tumor necrosis factor receptor-associated protein 1 protects cardiomyocytes against hypoxia, but the underlying mechanisms are not completely understood. In the present study, we used gain- and loss-of-function approaches to explore the effects of tumor necrosis factor receptor-associated protein 1 and cytochrome c oxidase subunit II on energy production in hypoxic cardiomyocytes. Hypoxia repressed ATP production in cultured cardiomyocytes, whereas overexpression of tumor necrosis factor receptor-associated protein 1 significantly improved ATP production. Conversely, knockdown of tumor necrosis factor receptor-associated protein 1 facilitated the hypoxia-induced decrease in ATP synthesis. Further investigation revealed that tumor necrosis factor receptor-associated protein 1 induced the expression and activity of cytochrome c oxidase subunit II, a component of cytochrome c oxidase that is important in mitochondrial respiratory chain function. Moreover, lentiviral-mediated overexpression of cytochrome c oxidase subunit II antagonized the decrease in ATP synthesis caused by knockdown of tumor necrosis factor receptor-associated protein 1, whereas knockdown of cytochrome c oxidase subunit II attenuated the increase in ATP synthesis caused by overexpression of tumor necrosis factor receptor-associated protein 1. In addition, inhibition of cytochrome c oxidase subunit II by a specific inhibitor sodium azide suppressed the ATP sy nthesis induced by overexpressed tumor necrosis factor receptor-associated protein 1. Hence, tumor necrosis factor receptor-associated protein 1 protects cardiomyocytes from hypoxia at least partly via potentiation of energy generation, and cytochrome c oxidase subunit II is one of the downstream effectors that mediates the tumor necrosis factor receptor-associated protein 1-mediated energy generation program.

  15. Association of Common Polymorphisms in the Nicotinic Acetylcholine Receptor Alpha4 Subunit Gene with an Electrophysiological Endophenotype in a Large Population-Based Sample.

    Directory of Open Access Journals (Sweden)

    A Mobascher

    Full Text Available Variation in genes coding for nicotinic acetylcholine receptor (nAChR subunits affect cognitive processes and may contribute to the genetic architecture of neuropsychiatric disorders. Single nucleotide polymorphisms (SNPs in the CHRNA4 gene that codes for the alpha4 subunit of alpha4/beta2-containing receptors have previously been implicated in aspects of (mostly visual attention and smoking-related behavioral measures. Here we investigated the effects of six synonymous but functional CHRNA4 exon 5 SNPs on the N100 event-related potential (ERP, an electrophysiological endophenotype elicited by a standard auditory oddball. A total of N = 1,705 subjects randomly selected from the general population were studied with electroencephalography (EEG as part of the German Multicenter Study on nicotine addiction. Two of the six variants, rs1044396 and neighboring rs1044397, were significantly associated with N100 amplitude. This effect was pronounced in females where we also observed an effect on reaction time. Sequencing of the complete exon 5 region in the population sample excluded the existence of additional/functional variants that may be responsible for the observed effects. This is the first large-scale population-based study investigation the effects of CHRNA4 SNPs on brain activity measures related to stimulus processing and attention. Our results provide further evidence that common synonymous CHRNA4 exon 5 SNPs affect cognitive processes and suggest that they also play a role in the auditory system. As N100 amplitude reduction is considered a schizophrenia-related endophenotype the SNPs studied here may also be associated with schizophrenia outcome measures.

  16. Comparative study of the distribution of the alpha-subunits of voltage-gated sodium channels in normal and axotomized rat dorsal root ganglion neurons.

    Science.gov (United States)

    Fukuoka, Tetsuo; Kobayashi, Kimiko; Yamanaka, Hiroki; Obata, Koichi; Dai, Yi; Noguchi, Koichi

    2008-09-10

    We compared the distribution of the alpha-subunit mRNAs of voltage-gated sodium channels Nav1.1-1.3 and Nav1.6-1.9 and a related channel, Nax, in histochemically identified neuronal subpopulations of the rat dorsal root ganglia (DRG). In the naïve DRG, the expression of Nav1.1 and Nav1.6 was restricted to A-fiber neurons, and they were preferentially expressed by TrkC neurons, suggesting that proprioceptive neurons possess these channels. Nav1.7, -1.8, and -1.9 mRNAs were more abundant in C-fiber neurons compared with A-fiber ones. Nax was evenly expressed in both populations. Although Nav1.8 and -1.9 were preferentially expressed by TrkA neurons, other alpha-subunits were expressed independently of TrkA expression. Actually, all IB4(+) neurons expressed both Nav1.8 and -1.9, and relatively limited subpopulations of IB4(+) neurons (3% and 12%, respectively) expressed Nav1.1 and/or Nav1.6. These findings provide useful information in interpreting the electrophysiological characteristics of some neuronal subpopulations of naïve DRG. After L5 spinal nerve ligation, Nav1.3 mRNA was up-regulated mainly in A-fiber neurons in the ipsilateral L5 DRG. Although previous studies demonstrated that nerve growth factor (NGF) and glial cell-derived neurotrophic factor (GDNF) reversed this up-regulation, the Nav1.3 induction was independent of either TrkA or GFRalpha1 expression, suggesting that the induction of Nav1.3 may be one of the common responses of axotomized DRG neurons without a direct relationship to NGF/GDNF supply. (c) 2008 Wiley-Liss, Inc.

  17. Structural bases of dimerization of yeast telomere protein Cdc13 and its interaction with the catalytic subunit of DNA polymerase [alpha

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Jia; Yang, Yuting; Wan, Ke; Mao, Ninghui; Yu, Tai-Yuan; Lin, Yi-Chien; DeZwaan, Diane C.; Freeman, Brian C.; Lin, Jing-Jer; Lue, Neal F.; Lei, Ming

    2011-08-24

    Budding yeast Cdc13-Stn1-Ten1 (CST) complex plays an essential role in telomere protection and maintenance, and has been proposed to be a telomere-specific replication protein A (RPA)-like complex. Previous genetic and structural studies revealed a close resemblance between Stn1-Ten1 and RPA32-RPA14. However, the relationship between Cdc13 and RPA70, the largest subunit of RPA, has remained unclear. Here, we report the crystal structure of the N-terminal OB (oligonucleotide/oligosaccharide binding) fold of Cdc13. Although Cdc13 has an RPA70-like domain organization, the structures of Cdc13 OB folds are significantly different from their counterparts in RPA70, suggesting that they have distinct evolutionary origins. Furthermore, our structural and biochemical analyses revealed unexpected dimerization by the N-terminal OB fold and showed that homodimerization is probably a conserved feature of all Cdc13 proteins. We also uncovered the structural basis of the interaction between the Cdc13 N-terminal OB fold and the catalytic subunit of DNA polymerase {alpha} (Pol1), and demonstrated a role for Cdc13 dimerization in Pol1 binding. Analysis of the phenotypes of mutants defective in Cdc13 dimerization and Cdc13-Pol1 interaction revealed multiple mechanisms by which dimerization regulates telomere lengths in vivo. Collectively, our findings provide novel insights into the mechanisms and evolution of Cdc13.

  18. Structure-function relationships in the Na,K-ATPase. cap alpha. subunit: site-directed mutagenesis of glutamine-111 to arginine and asparagine-122 to aspartic acid generates a ouabain-resistant enzyme

    Energy Technology Data Exchange (ETDEWEB)

    Price, E.M.; Lingrel, J.B.

    1988-11-01

    Na,K-ATPases from various species differ greatly in their sensitivity to cardiac glycosides such as ouabain. The sheep and human enzymes are a thousand times more sensitive than the corresponding ones from rat and mouse. To define the region of the ..cap alpha..1 subunit responsible for this differential sensitivity, chimeric cDNAs of sheep and rat were constructed and expressed in ouabain-sensitive HeLa cells. The construct containing the amino-terminal half of the rat ..cap alpha..1 subunit coding region and carboxyl-terminal half of the sheep conferred the ouabain-resistant phenotype to HeLa cells while the reverse construct did not. This indicates that the determinants involved in ouabain sensitivity are located in the amino-terminal half of the Na,K-ATPase ..cap alpha.. subunit. By use of site-directed mutagenesis, the amino acid sequence of the first extracellular domain (H1-H2) of the sheep ..cap alpha..1 subunit was changed to that of the rat. When expressed in HeLa cells, this mutated sheep ..cap alpha..1 construct, like the rat/sheep chimera, was able to confer ouabain resistance to these cells. Furthermore, similar results were observed when HeLa cells were transfected with a sheep ..cap alpha..1 cDNA containing only two amino acid substitutions. The resistant cells, whether transfected with the rat ..cap alpha..1 cDNA, the rat/sheep chimera, or the mutant sheep ..cap alpha..1 cDNAs, exhibited identical biochemical characteristics including ouabain-inhibitable cell growth, /sup 86/Rb/sup +/ uptake, and Na,K-ATPase activity. These results demonstrate that the presence of arginine and aspartic acid on the amino end and carboxyl end, respectively, of the H1-H2 extracellular domain of the Na,K-ATPase ..cap alpha.. subunit together is responsible for the ouabain-resistant character of the rat enzyme and the corresponding residues in the sheep ..cap alpha..1 subunit (glutamine and asparagine) are somehow involved in ouabain binding.

  19. An antisense oligodeoxynucleotide targeted against the type II sub. beta. regulatory subunit mRNA of protein kinase inhibits cAMP-induced differentiation in HL-60 leukemia cells without affecting phorbol ester effects

    Energy Technology Data Exchange (ETDEWEB)

    Tortora, G.; Clair, T.; Cho-Chung, Y.S. (National Institutes of Health, Bethesda, MD (USA))

    1990-01-01

    The type II{sub {beta}} regulatory subunit of cAMP-dependent protein kinase (RII{sub {beta}}) has been hypothesized to play an important role in the growth inhibition and differentiation induced by site-selective cAMP analogs in human cancer cells, but direct proof of this function has been lacking. To address this tissue, HL-60 human promyelocytic leukemia cells were exposed to RII{sub {beta}} antisense synthetic oligodeoxynucleotide, and the effects on cAMP-induced growth regulation were examined. Exposure of these cells to RII{sub {beta}} antisense oligodeoxynucleotide resulted in a decrease in cAMP analog-induced growth inhibition and differentiation without apparent effect on differentiation induced by phorbol esters. This loss in cAMP growth regulatory function correlated with a decrease in basal and induced levels of RII{sub {beta}} protein. Exposure to RII{sub {beta}} sense, RI{sub {alpha}} and RII{sub {alpha}} antisense, or irrelevant oligodeoxynucleotides had no such effect. These results show that the RII{sub {beta}} regulatory subunit of protein kinase plays a critical role in the cAMP-induced growth regulation of HL-60 leukemia cells.

  20. Phenotypic consequences of deletion of the {gamma}{sub 3}, {alpha}{sub 5}, or {beta}{sub 3} subunit of the type A {gamma}-aminobutyric acid receptor in mice

    Energy Technology Data Exchange (ETDEWEB)

    Culia, C.T.; Stubbs, L.J.; Montgomery, C.S.; Russell, L.B.; Rinchik, E.M. [Oak Ridge National Lab., TN (United States)

    1994-03-29

    Three genes (Gabrg3, Gabra5, and Gabrb3) encoding the {gamma}{sub 3}, {alpha}{sub 5}, and {beta}{sub 3} subunits of the type A {gamma}-aminobutyric acid receptor, respectively, are known to map near the pink-eyed dilution (p) locus in mouse chromosome 7. This region shares homology with a segment of human chromosome 15 that is implicated in Angelman syndrome, an inherited neurobehavioral disorder. By mapping Gabrg3-Gabra5-Gabrb3-telomere. Like Gabrb3, neither the Gabra5 nor Gabrg3 gene is functionally imprinted in adult mouse brain. Mice deleted for all three subunits die at birth with a cleft palate, although there are rare survivors ({approximately} 5%) that do not have a cleft palate but do exhibit a neurological abnormality characterized by tremor, jerky gait, and runtiness. The authors have previously suggested that deficiency of the {beta}{sub 3} subunit may be responsible for the clefting defect. Most notably, however, in this report they describe mice carrying two overlapping, complementing p deletions that fail to express the {gamma}{sub 3} transcript, as well as mice from another line that express neither the {gamma}{sub 3} nor {alpha}{sub 5} transcripts. Surprisingly, mice from both of these lines are phenotypically normal and do not exhibit any of the neurological symptoms characteristic of the rare survivors that are deleted for all three ({gamma}{sub 3}, {alpha}{sub 5}, and {beta}{sub 3}) subunits. These mice therefore provide a whole-organism type A {gamma}-aminobutyric-acid receptor background that is devoid of any receptor subtypes that normally contain the {gamma}{sub 3} and/or {alpha}{sub 5} subunits. The absence of an overt neurological phenotype in mice lacking the {gamma}{sub 3} and/or {alpha}{sub 5} subunits also suggests that mutations in these genes are unlikely to provide useful animal models for Angelman syndrome in humans.

  1. An anilinoquinazoline derivative inhibits tumor growth through interaction with hCAP-G2, a subunit of condensin II.

    Directory of Open Access Journals (Sweden)

    Hirokazu Shiheido

    Full Text Available We screened 46 novel anilinoquinazoline derivatives for activity to inhibit proliferation of a panel of human cancer cell lines. Among them, Q15 showed potent in vitro growth-inhibitory activity towards cancer cell lines derived from colorectal cancer, lung cancer and multiple myeloma. It also showed antitumor activity towards multiple myeloma KMS34 tumor xenografts in lcr/scid mice in vivo. Unlike the known anilinoquinazoline derivative gefitinib, Q15 did not inhibit cytokine-mediated intracellular tyrosine phosphorylation. Using our mRNA display technology, we identified hCAP-G2, a subunit of condensin II complex, which is regarded as a key player in mitotic chromosome condensation, as a Q15 binding partner. Immunofluorescence study indicated that Q15 compromises normal segregation of chromosomes, and therefore might induce apoptosis. Thus, our results indicate that hCAP-G2 is a novel therapeutic target for development of drugs active against currently intractable neoplasms.

  2. Metallothionein 2A affects the cell respiration by suppressing the expression of mitochondrial protein cytochrome c oxidase subunit II.

    Science.gov (United States)

    Bragina, Olga; Gurjanova, Karina; Krishtal, Jekaterina; Kulp, Maria; Karro, Niina; Tõugu, Vello; Palumaa, Peep

    2015-06-01

    Metallothioneins (MT) are involved in a broad range of cellular processes and play a major role in protection of cells towards various stressors. Two functions of MTs, namely the maintaining of the homeostasis of transition metal ions and the redox balance, are directly linked to the functioning of mitochondria. Dyshomeostasis of MTs is often related with malfunctioning of mitochondria; however, the mechanism by which MTs affect the mitochondrial respiratory chain is still unknown. We demonstrated that overexpression of MT-2A in HEK cell line decreased the oxidative phosphorylation capacity of the cells. HEK cells overexpressing MT-2A demonstrated reduced oxygen consumption and lower cellular ATP levels. MT-2A did not affect the number of mitochondria, but reduced specifically the level of cytochrome c oxidase subunit II protein, which resulted in lower activity of the complex IV.

  3. Fe K alpha and hydrodynamic loop model diagnostics for a large flare on II Peg

    CERN Document Server

    Ercolano, Barbara; Reale, Fabio; Testa, Paola; Miller, Jon M

    2008-01-01

    The observation by the Swift X-ray Telescope of the Fe K alpha_1, alpha_2 doublet during a large flare on the RS CVn binary system II Peg represents one of only two firm detections to date of photospheric Fe K alpha from a star other than our Sun. We present models of the Fe K alpha equivalent widths reported in the literature for the II Peg observations and show that they are most probably due to fluorescence following inner shell photoionisation of quasi-neutral Fe by the flare X-rays. Our models constrain the maximum height of flare the to 0.15 R_* assuming solar abundances for the photospheric material, and 0.1 R_* and 0.06 R_* assuming depleted photospheric abundances ([M/H]=-0.2 and [M/H]=-0.4, respectively). Accounting for an extended loop geometry has the effect of increasing the estimated flare heights by a factor of ~3. These predictions are consistent with those derived using results of flaring loop models, which are also used to estimate the flaring loop properties and energetics. From loop models...

  4. Introduction of all-hydrocarbon i,i+3 staples into alpha-helices via ring-closing olefin metathesis.

    Science.gov (United States)

    Kim, Young-Woo; Kutchukian, Peter S; Verdine, Gregory L

    2010-07-02

    The introduction of all-hydrocarbon i,i+3 staples into alpha-helical peptide scaffolds via ring-closing olefin metathesis (RCM) between two alpha-methyl,alpha-pentenylglycine residues incorporated at i and i+3 positions, which lie on the same face of the helix, has been investigated. The reactions were found to be highly dependent upon the side-chain stereochemistry of the amino acids undergoing RCM. The i,i+3 stapling system established here provides a potentially useful alternative to the well-established i,i+4 stapling system now in widespread use.

  5. Maternal topoisomerase II alpha, not topoisomerase II beta, enables embryonic development of zebrafish top2a-/- mutants

    LENUS (Irish Health Repository)

    Sapetto-Rebow, Beata

    2011-11-23

    Abstract Background Genetic alterations in human topoisomerase II alpha (TOP2A) are linked to cancer susceptibility. TOP2A decatenates chromosomes and thus is necessary for multiple aspects of cell division including DNA replication, chromosome condensation and segregation. Topoisomerase II alpha is also required for embryonic development in mammals, as mouse Top2a knockouts result in embryonic lethality as early as the 4-8 cell stage. The purpose of this study was to determine whether the extended developmental capability of zebrafish top2a mutants arises from maternal expression of top2a or compensation from its top2b paralogue. Results Here, we describe bloody minded (blm), a novel mutant of zebrafish top2a. In contrast to mouse Top2a nulls, zebrafish top2a mutants survive to larval stages (4-5 day post fertilization). Developmental analyses demonstrate abundant expression of maternal top2a but not top2b. Inhibition or poisoning of maternal topoisomerase II delays embryonic development by extending the cell cycle M-phase. Zygotic top2a and top2b are co-expressed in the zebrafish CNS, but endogenous or ectopic top2b RNA appear unable to prevent the blm phenotype. Conclusions We conclude that maternal top2a enables zebrafish development before the mid-zygotic transition (MZT) and that zebrafish top2a and top2b are not functionally redundant during development after activation of the zygotic genome.

  6. Maternal topoisomerase II alpha, not topoisomerase II beta, enables embryonic development of zebrafish top2a-/- mutants

    Directory of Open Access Journals (Sweden)

    Sapetto-Rebow Beata

    2011-11-01

    Full Text Available Abstract Background Genetic alterations in human topoisomerase II alpha (TOP2A are linked to cancer susceptibility. TOP2A decatenates chromosomes and thus is necessary for multiple aspects of cell division including DNA replication, chromosome condensation and segregation. Topoisomerase II alpha is also required for embryonic development in mammals, as mouse Top2a knockouts result in embryonic lethality as early as the 4-8 cell stage. The purpose of this study was to determine whether the extended developmental capability of zebrafish top2a mutants arises from maternal expression of top2a or compensation from its top2b paralogue. Results Here, we describe bloody minded (blm, a novel mutant of zebrafish top2a. In contrast to mouse Top2a nulls, zebrafish top2a mutants survive to larval stages (4-5 day post fertilization. Developmental analyses demonstrate abundant expression of maternal top2a but not top2b. Inhibition or poisoning of maternal topoisomerase II delays embryonic development by extending the cell cycle M-phase. Zygotic top2a and top2b are co-expressed in the zebrafish CNS, but endogenous or ectopic top2b RNA appear unable to prevent the blm phenotype. Conclusions We conclude that maternal top2a enables zebrafish development before the mid-zygotic transition (MZT and that zebrafish top2a and top2b are not functionally redundant during development after activation of the zygotic genome.

  7. Constitutive Activation of the G-Protein Subunit G[alpha]s within Forebrain Neurons Causes PKA-Dependent Alterations in Fear Conditioning and Cortical "Arc" mRNA Expression

    Science.gov (United States)

    Kelly, Michele P.; Cheung, York-Fong; Favilla, Christopher; Siegel, Steven J.; Kanes, Stephen J.; Houslay, Miles D.; Abel, Ted

    2008-01-01

    Memory formation requires cAMP signaling; thus, this cascade has been of great interest in the search for cognitive enhancers. Given that medications are administered long-term, we determined the effects of chronically increasing cAMP synthesis in the brain by expressing a constitutively active isoform of the G-protein subunit G[alpha]s…

  8. Zolpidem, a selective GABA(A) receptor alpha1 subunit agonist, induces comparable Fos expression in oxytocinergic neurons of the hypothalamic paraventricular and accessory but not supraoptic nuclei in the rat

    DEFF Research Database (Denmark)

    Kiss, Alexander; Søderman, Andreas; Bundzikova, Jana;

    2006-01-01

    Functional activation of oxytocinergic (OXY) cells in the hypothalamic paraventricular (PVN), supraoptic (SON), and accessory (ACC) nuclei was investigated in response to acute treatment with Zolpidem (a GABA(A) receptor agonist with selectivity for alpha(1) subunits) utilizing dual Fos/OXY immun...

  9. Zolpidem, a selective GABA(A) receptor alpha1 subunit agonist, induces comparable Fos expression in oxytocinergic neurons of the hypothalamic paraventricular and accessory but not supraoptic nuclei in the rat

    DEFF Research Database (Denmark)

    Kiss, Alexander; Søderman, Andreas; Bundzikova, Jana

    2006-01-01

    Functional activation of oxytocinergic (OXY) cells in the hypothalamic paraventricular (PVN), supraoptic (SON), and accessory (ACC) nuclei was investigated in response to acute treatment with Zolpidem (a GABA(A) receptor agonist with selectivity for alpha(1) subunits) utilizing dual Fos/OXY immun...

  10. CRYSTAL-STRUCTURE OF DEOXYGENATED LIMULUS-POLYPHEMUS SUBUNIT-II HEMOCYANIN AT 2.18-ANGSTROM RESOLUTION - CLUES FOR A MECHANISM FOR ALLOSTERIC REGULATION

    NARCIS (Netherlands)

    HAZES, B; MAGNUS, KA; BONAVENTURA, C; BONAVENTURA, J; DAUTER, Z; KALK, KH; HOL, WGJ

    The crystal structure of Limulus polyphemus subunit type II hemocyanin in the deoxygenated state has been determined to a resolution of 2.18 angstrom. Phase information for this first structure of a cheliceratan hemocyanin was obtained by molecular replacement using the crustacean hemocyanin

  11. CRYSTAL-STRUCTURE OF DEOXYGENATED LIMULUS-POLYPHEMUS SUBUNIT-II HEMOCYANIN AT 2.18-ANGSTROM RESOLUTION - CLUES FOR A MECHANISM FOR ALLOSTERIC REGULATION

    NARCIS (Netherlands)

    HAZES, B; MAGNUS, KA; BONAVENTURA, C; BONAVENTURA, J; DAUTER, Z; KALK, KH; HOL, WGJ

    1993-01-01

    The crystal structure of Limulus polyphemus subunit type II hemocyanin in the deoxygenated state has been determined to a resolution of 2.18 angstrom. Phase information for this first structure of a cheliceratan hemocyanin was obtained by molecular replacement using the crustacean hemocyanin structu

  12. Isolation of monomeric photosystem II that retains the subunit PsbS.

    Science.gov (United States)

    Haniewicz, Patrycja; De Sanctis, Daniele; Büchel, Claudia; Schröder, Wolfgang P; Loi, Maria Cecilia; Kieselbach, Thomas; Bochtler, Matthias; Piano, Dario

    2013-12-01

    Photosystem II has been purified from a transplastomic strain of Nicotiana tabacum according to two different protocols. Using the procedure described in Piano et al. (Photosynth Res 106:221-226, 2010) it was possible to isolate highly active PSII composed of monomers and dimers but depleted in their PsbS protein content. A "milder" procedure than the protocol reported by Fey et al. (Biochim Biophys Acta 1777:1501-1509, 2008) led to almost exclusively monomeric PSII complexes which in part still bind the PsbS protein. This finding might support a role for PSII monomers in higher plants.

  13. Inhibin alpha-subunit (INHA expression in adrenocortical cancer is linked to genetic and epigenetic INHA promoter variation.

    Directory of Open Access Journals (Sweden)

    Johannes Hofland

    Full Text Available Adrenocortical carcinoma (ACC is a rare, but highly malignant tumor of unknown origin. Inhibin α-subunit (Inha knockout mice develop ACCs following gonadectomy. In man, INHA expression varies widely within ACC tissues and its circulating peptide inhibin pro-αC has been described as a novel tumor marker for ACC. We investigated whether genetic and epigenetic changes of the INHA gene in human ACC cause loss or variation of INHA expression. To this end, analyses of INHA sequence, promoter methylation and mRNA expression were performed in human adrenocortical tissues. Serum inhibin pro-αC levels were also measured in ACC patients. INHA genetic analysis in 37 unique ACCs revealed 10 novel, heterozygous rare variants. Of the 3 coding bases affected, one variant was synonymous and two were missense variants: S72F and S184F. The minor allele of rs11893842 at -124 bp was observed at a low frequency (24% in ACC samples and was associated with decreased INHA mRNA levels: 4.7±1.9 arbitrary units for AA, compared to 26±11 for AG/GG genotypes (P = 0.034. The methylation of four proximal INHA promoter CpGs was aberrantly increased in five ACCs (47.7±3.9%, compared to normal adrenals (18.4±0.6%, P = 0.0052, whereas the other 14 ACCs studied showed diminished promoter methylation (9.8±1.1%, P = 0.020. CpG methylation was inversely correlated to INHA mRNA levels in ACCs (r = -0.701, p = 0.0036, but not associated with serum inhibin pro-αC levels. In conclusion, aberrant methylation and common genetic variation in the INHA promoter occur in human ACCs and are associated with decreased INHA expression.

  14. Inhibin Alpha-Subunit (INHA) Expression in Adrenocortical Cancer Is Linked to Genetic and Epigenetic INHA Promoter Variation

    Science.gov (United States)

    Hofland, Johannes; Steenbergen, Jacobie; Voorsluijs, Jacoba M.; Verbiest, Michael M. P. J.; de Krijger, Ronald R.; Hofland, Leo J.; de Herder, Wouter W.; Uitterlinden, Andre G.; Feelders, Richard A.; de Jong, Frank H.

    2014-01-01

    Adrenocortical carcinoma (ACC) is a rare, but highly malignant tumor of unknown origin. Inhibin α-subunit (Inha) knockout mice develop ACCs following gonadectomy. In man, INHA expression varies widely within ACC tissues and its circulating peptide inhibin pro-αC has been described as a novel tumor marker for ACC. We investigated whether genetic and epigenetic changes of the INHA gene in human ACC cause loss or variation of INHA expression. To this end, analyses of INHA sequence, promoter methylation and mRNA expression were performed in human adrenocortical tissues. Serum inhibin pro-αC levels were also measured in ACC patients. INHA genetic analysis in 37 unique ACCs revealed 10 novel, heterozygous rare variants. Of the 3 coding bases affected, one variant was synonymous and two were missense variants: S72F and S184F. The minor allele of rs11893842 at −124 bp was observed at a low frequency (24%) in ACC samples and was associated with decreased INHA mRNA levels: 4.7±1.9 arbitrary units for AA, compared to 26±11 for AG/GG genotypes (P = 0.034). The methylation of four proximal INHA promoter CpGs was aberrantly increased in five ACCs (47.7±3.9%), compared to normal adrenals (18.4±0.6%, P = 0.0052), whereas the other 14 ACCs studied showed diminished promoter methylation (9.8±1.1%, P = 0.020). CpG methylation was inversely correlated to INHA mRNA levels in ACCs (r = −0.701, p = 0.0036), but not associated with serum inhibin pro-αC levels. In conclusion, aberrant methylation and common genetic variation in the INHA promoter occur in human ACCs and are associated with decreased INHA expression. PMID:25111790

  15. A vacuolar-type proton (H+) translocating ATPase alpha subunit encoded by the Hc-vha-6 gene of Haemonchus contortus.

    Science.gov (United States)

    Hu, Min; He, Li; Campbell, Bronwyn E; Zhong, Weiwei; Sternberg, Paul W; Gasser, Robin B

    2010-08-01

    In the present study, a full-length cDNA (designated Hc-vha-6) inferred to encode an alpha subunit of a vacuolar-type proton translocating adenosine triphosphatase (V-ATPase) was isolated from the parasitic nematode Haemonchus contortus, and characterized. The transcript for Hc-vha-6 was detected in all developmental stages and both sexes of H. contortus. Elements, including two TATA box (TATAA), two inverted CAAT box (ATTGG), five E box (CANNTG) and six GATA as well as five inverse GATA (TTATC) transcription factor motifs, were identified in the non-coding region upstream of Hc-vha-6. The open reading frame (ORF) of 2601 nucleotides encoded a protein (Hc-VHA-6) of 866 amino acids and a molecular weight of approximately 98.7 kDa. Comparison with a published protein sequence for a homologue (VPH1P) from yeast showed that Hc-VHA-6 had nine transmembrane domains and the 14 essential amino acid residues associated with enzyme activity, assembly, intracellular and/or membrane targeting. Phylogenetic analyses of selected amino acid sequence data revealed Hc-VHA-6 to be most closely related to VHA-6 of Caenorhabditis elegans. A predictive network analysis inferred that vha-6 interacts with at least seven other genes encoding V-ATPase subunits and a small Rab GTPase. This study provides the first insight into a V-ATPase of parasitic nematodes and a sound basis for future functional genomic work. Copyright 2010 Elsevier Ltd. All rights reserved.

  16. The Appearance of Spicules in High Resolution Observations of Ca II H and H-alpha

    CERN Document Server

    Pereira, Tiago M D; Carlsson, Mats

    2016-01-01

    Solar spicules are chromospheric fibrils that appear everywhere on the Sun, yet their origin is not understood. Using high resolution observations of spicules obtained with the Swedish 1-m Solar Telescope we aim to understand how spicules appear in filtergrams and Dopplergrams, how they compare in Ca II H and H-alpha, and what can make them appear and disappear. We find spicules display a rich and detailed spatial structure, and show a distribution of transverse velocities that when aligned with the line of sight can make them appear at different H-alpha wing positions. They become more abundant at positions closer to the line core, reflecting a distribution of Doppler shifts and widths. In H-alpha width maps they stand out as bright features both on disk and off-limb, reflecting their large Doppler motions and possibly higher temperatures than in the typical H-alpha formation region. Spicule lifetimes measured from narrowband images at only a few positions will be an underestimate because Doppler shifts can ...

  17. Protein crystallization and initial neutron diffraction studies of the photosystem II subunit PsbO.

    Science.gov (United States)

    Bommer, Martin; Coates, Leighton; Dau, Holger; Zouni, Athina; Dobbek, Holger

    2017-09-01

    The PsbO protein of photosystem II stabilizes the active-site manganese cluster and is thought to act as a proton antenna. To enable neutron diffraction studies, crystals of the β-barrel core of PsbO were grown in capillaries. The crystals were optimized by screening additives in a counter-diffusion setup in which the protein and reservoir solutions were separated by a 1% agarose plug. Crystals were cross-linked with glutaraldehyde. Initial neutron diffraction data were collected from a 0.25 mm(3) crystal at room temperature using the MaNDi single-crystal diffractometer at the Spallation Neutron Source, Oak Ridge National Laboratory.

  18. K+-Phosphatase activity of gill (Na+, K+)-ATPase from the blue crab, Callinectes danae: low-salinity acclimation and expression of the alpha-subunit.

    Science.gov (United States)

    Masui, D C; Furriel, R P M; Mantelatto, F L M; McNamara, J C; Leone, F A

    2005-04-01

    The kinetic properties of a microsomal gill (Na(+), K(+)) ATPase from the blue crab, Callinectes danae, acclimated to 15 per thousand salinity for 10 days, were analyzed using the substrate p-nitrophenylphosphate. The (Na(+), K(+))-ATPase hydrolyzed the substrate obeying Michaelian kinetics at a rate of V=102.9+/-4.3 U.mg(-1) with K(0.5)=1.7+/-0.1 mmol.L(-1), while stimulation by magnesium (V=93.7+/-2.3 U.mg(-1); K(0.5)=1.40+/-0.03 mmol.L(-1)) and potassium ions (V=94.9+/-3.5 U.mg(-1); K(0.5)=2.9+/-0.1 mmol.L(-1)) was cooperative. K(+)-phosphatase activity was also stimulated by ammonium ions to a rate of V=106.2+/-2.2 U. mg(-1) with K(0.5)=9.8+/-0.2 mmol.L(-1), following cooperative kinetics (n(H)=2.9). However, K(+)-phosphatase activity was not stimulated further by K(+) plus NH(4) (+) ions. Sodium ions (K(I)=22.7+/-1.7 mmol.L(-1)), and orthovanadate (K(I)=28.1+/-1.4 nmol.L(-1)) completely inhibited PNPPase activity while ouabain inhibition reached almost 75% (K(I)=142.0+/-7.1 micromol.L(-1)). Western blotting analysis revealed increased expression of the (Na(+), K(+))-ATPase alpha-subunit in crabs acclimated to 15 per thousand salinity compared to those acclimated to 33 per thousand salinity. The increase in (Na(+), K(+))-ATPase activity in C. danae gill tissue in response to low-salinity acclimation apparently derives from the increased expression of the (Na(+), K( (+) ))-ATPase alpha-subunit; phosphate-hydrolyzing enzymes other than (Na(+), K(+))-ATPase are also expressed. These findings allow a better understanding of the kinetic behavior of the enzymes that underlie the osmoregulatory mechanisms of euryhaline crustaceans. (c) 2005 Wiley-Liss, Inc.

  19. Structural basis of transcription inhibition by alpha-amanitin and implications for RNA polymerase II translocation.

    Science.gov (United States)

    Brueckner, Florian; Cramer, Patrick

    2008-08-01

    To study how RNA polymerase II translocates after nucleotide incorporation, we prepared elongation complex crystals in which pre- and post-translocation states interconvert. Crystal soaking with the inhibitor alpha-amanitin locked the elongation complex in a new state, which was refined at 3.4-A resolution and identified as a possible translocation intermediate. The DNA base entering the active site occupies a 'pretemplating' position above the central bridge helix, which is shifted and occludes the templating position. A leucine residue in the trigger loop forms a wedge at the shifted bridge helix, but moves by 13 A to close the active site during nucleotide incorporation. Our results support a Brownian ratchet mechanism that involves swinging of the trigger loop between open, wedged and closed positions, and suggest that alpha-amanitin impairs nucleotide incorporation and translocation by trapping the trigger loop and bridge helix.

  20. H-alpha features with hot onsets. II. A contrail fibril

    CERN Document Server

    Rutten, R J

    2016-01-01

    The solar chromosphere observed in H-alpha consists mostly of narrow fibrils. The longest typically originate in network or plage and arch far over adjacent internetwork. We use data from multiple telescopes to analyze one well-observed example in a quiet area. It resulted from the earlier passage of an accelerating disturbance in which the gas was heated to high temperature as in the spicule-II phenomenon. After this passage a dark H-Halpha fibril appeared as a contrail. We use Saha-Boltzmann extinction estimation to gauge the onset and subsequent visibilities in various diagnostics and conclude that such H-alpha fibrils can indeed be contrail phenomena, not indicative of the thermodynamic and magnetic environment when they are observed but of more dynamic happenings before. They do not connect across internetwork cells but represent launch tracks of heating events and chart magnetic field during launch, not at present.

  1. [The clinical significance of PIVKA-II determination in patients with hepatocellular carcinoma: a comparative study with alpha-fetoprotein].

    Science.gov (United States)

    Sakon, M; Monden, M; Goto, M; Kanai, T; Umeshita, K; Endo, W; Mori, T

    1990-05-01

    The changes in the plasma level of PIVKA-II (Protein Induced by Vitamin K Absence or Antagonist-II) following the treatment or progress of the disease was studied in 60 patients with hepatocellular carcinoma. The positivity rate determined by the changes in PIVKA-II was 58.4 percent (35/60 cases) and was about the same as those reported so far, all of which were obtained by a single determination of PIVKA-II. Plasma PIVKA-II was elevated in 61.9 percent (13/21 cases) of alpha-fetoprotein negative patients and it was almost identical with the overall positivity rate. In parallel with serum alpha-fetoprotein, the plasma level of PIVKA-II was decreased after the surgery or transcatheter arterial embolization and was increased when the recurrence or progress of the disease was observed. Furthermore, the nonspecific elevation of PIVKA-II due to the associated liver cirrhosis or chronic hepatitis was infrequent compared with that of alpha-fetoprotein. In 18 cases positive with both PIVKA-II and alpha-fetoprotein, a close correlation (R = 0.91) was observed between the changes of these markers during the progress or treatment of the disease. Thus, it was suggested that determination of PIVKA-II in blood might be useful not only in the diagnosis but in monitoring the progress or the effectiveness of treatments in hepatocellular carcinoma.

  2. Regulation of the nuclear gene that encodes the alpha-subunit of the mitochondrial F0F1-ATP synthase complex. Activation by upstream stimulatory factor 2.

    Science.gov (United States)

    Breen, G A; Jordan, E M

    1997-04-18

    We have previously identified several positive cis-acting regulatory regions in the promoters of the bovine and human nuclear-encoded mitochondrial F0F1-ATP synthase alpha-subunit genes (ATPA). One of these cis-acting regions contains the sequence 5'-CACGTG-3' (an E-box), to which a number of transcription factors containing a basic helix-loop-helix motif can bind. This E-box element is required for maximum activity of the ATPA promoter in HeLa cells. The present study identifies the human transcription factor, upstream stimulatory factor 2 (USF2), as a nuclear factor that binds to the ATPA E-box and demonstrates that USF2 plays a critical role in the activation of the ATPA gene in vivo. Evidence includes the following. Antiserum directed against USF2 recognized factors present in HeLa nuclear extracts that interact with the ATPA promoter in mobility shift assays. Wild-type USF2 proteins synthesized from expression vectors trans-activated the ATPA promoter through the E-box, whereas truncated USF2 proteins devoid of the amino-terminal activation domains did not. Importantly, expression of a dominant-negative mutant of USF2 lacking the basic DNA binding domain but able to dimerize with endogenous USF proteins significantly reduced the level of activation of the ATPA promoter caused by ectopically coexpressed USF2, demonstrating the importance of endogenous USF2 in activation of the ATPA gene.

  3. An intact F1ATPase alpha-subunit gene and a pseudogene with differing genomic organization are detected in both male-fertile and CMS petunia mitochondria.

    Science.gov (United States)

    Yesodi, V; Hauschner, H; Tabib, Y; Firon, N

    1997-11-01

    The gene copies for the alpha-subunit of the mitochondrial F1ATPase (atpA) were isolated and characterized in both male-fertile and cytoplasmic male sterile (CMS) petunia. Two copies, an intact gene and a truncated gene, were detected in both cytoplasms. The accumulated data, based upon a comparison of the sequences (the open reading frames as well as the 5' and 3' flanking regions) of the two atpA copies, both in male-fertile and CMS Petunia, indicate that: (1) they differ in their genomic organization and (2) a common progenitor cytoplasm, containing two copies of an intact atpA sequence, served as the origin for the atpA copies of the fertility and CMS-inducing cytoplasms. Homologous recombination through the progenitor intact atpA sequences is assumed to have caused the rearrangement in the 3' portion of the atpA open reading frame and the generation of the truncated atpA gene. It is thus suggested that the atpA pseudogenes, in both male-fertile and CMS cytoplasms, originated from a common progenitor atpA pseudogene sequence.

  4. Susceptibility effects of GABA receptor subunit alpha-2 (GABRA2) variants and parental monitoring on externalizing behavior trajectories: Risk and protection conveyed by the minor allele.

    Science.gov (United States)

    Trucco, Elisa M; Villafuerte, Sandra; Heitzeg, Mary M; Burmeister, Margit; Zucker, Robert A

    2016-02-01

    Understanding factors increasing susceptibility to social contexts and predicting psychopathology can help identify targets for prevention. Persistently high externalizing behavior in adolescence is predictive of psychopathology in adulthood. Parental monitoring predicts low externalizing behavior, yet youth likely vary in the degree to which they are affected by parents. Genetic variants of GABA receptor subunit alpha-2 (GABRA2) may increase susceptibility to parental monitoring, thus impacting externalizing trajectories. We had several objectives: (a) to determine whether GABRA2 (rs279827, rs279826, rs279858) moderates the relationship between a component of parental monitoring, parental knowledge, and externalizing trajectories; (b) to test the form of this interaction to assess whether GABRA2 variants reflect risk (diathesis-stress) or susceptibility (differential susceptibility) factors; and (c) to clarify GABRA2 associations on the development of problem behavior. This prospective study (N = 504) identified three externalizing trajectory classes (i.e., low, decreasing, and high) across adolescence. A GABRA2 × Parental Monitoring effect on class membership was observed, such that A-carriers were largely unaffected by parental monitoring, whereas class membership for those with the GG genotype was affected by parental monitoring. Findings support differential susceptibility in GABRA2.

  5. INCURVATA2 encodes the catalytic subunit of DNA Polymerase alpha and interacts with genes involved in chromatin-mediated cellular memory in Arabidopsis thaliana.

    Science.gov (United States)

    Barrero, José María; González-Bayón, Rebeca; del Pozo, Juan Carlos; Ponce, María Rosa; Micol, José Luis

    2007-09-01

    Cell type-specific gene expression patterns are maintained by the stable inheritance of transcriptional states through mitosis, requiring the action of multiprotein complexes that remodel chromatin structure. Genetic and molecular interactions between chromatin remodeling factors and components of the DNA replication machinery have been identified in Schizosaccharomyces pombe, indicating that some epigenetic marks are replicated simultaneously to DNA with the participation of the DNA replication complexes. This model of epigenetic inheritance might be extended to the plant kingdom, as we report here with the positional cloning and characterization of INCURVATA2 (ICU2), which encodes the putative catalytic subunit of the DNA polymerase alpha of Arabidopsis thaliana. The strong icu2-2 and icu2-3 insertional alleles caused fully penetrant zygotic lethality when homozygous and incompletely penetrant gametophytic lethality, probably because of loss of DNA polymerase activity. The weak icu2-1 allele carried a point mutation and caused early flowering, leaf incurvature, and homeotic transformations of sepals into carpels and of petals into stamens. Further genetic analyses indicated that ICU2 interacts with TERMINAL FLOWER2, the ortholog of HETEROCHROMATIN PROTEIN1 of animals and yeasts, and with the Polycomb group (PcG) gene CURLY LEAF. Another PcG gene, EMBRYONIC FLOWER2, was found to be epistatic to ICU2. Quantitative RT-PCR analyses indicated that a number of regulatory genes were derepressed in the icu2-1 mutant, including genes associated with flowering time, floral meristem, and floral organ identity.

  6. Molecular Cloning, Structural Analysis and Tissue Expression of Protein Phosphatase 3 Catalytic Subunit Alpha Isoform (PPP3CA Gene in Tianfu Goat Muscle

    Directory of Open Access Journals (Sweden)

    Lu Wan

    2014-02-01

    Full Text Available Calcineurin, a Ca2+/calmodulin-dependent protein phosphatase, plays a critical role in controlling skeletal muscle fiber type. However, little information is available concerning the expression of calcineurin in goat. Therefore, protein phosphatase 3 catalytic subunit alpha isoform (PPP3CA gene, also called calcineurin Aα, was cloned and its expression characterized in Tianfu goat muscle. Real time quantitative polymerase chain reaction (RT-qPCR analyses revealed that Tianfu goat PPP3CA was detected in cardiac muscle, biceps femoris muscle, abdominal muscle, longissimus dors muscle, and soleus muscle. High expression levels were found in biceps femoris muscle, longissimus muscle and abdominal muscle (p < 0.01, and low expression levels were seen in cardiac muscle and soleus muscle (p > 0.05. In addition, the spatial-temporal mRNA expression levels showed different variation trends in different muscles with the age of the goats. Western blotting further revealed that PPP3CA protein was expressed in the above-mentioned tissues, with the highest level in biceps femoris muscle, and the lowest level in soleus muscle. In this study, we isolated the full-length coding sequence of Tianfu goat PPP3CA gene, analyzed its structure, and investigated its expression in different muscle tissues from different age stages. These results provide a foundation for understanding the function of the PPP3CA gene in goats.

  7. The essential role of hippocampal alpha6 subunit-containing GABAA receptors in maternal separation stress-induced adolescent depressive behaviors.

    Science.gov (United States)

    Yang, Linjie; Xu, Ting; Zhang, Ke; Wei, Zhisheng; Li, Xuran; Huang, Mingfa; Rose, Gregory M; Cai, Xiang

    2016-10-15

    Exposure to early stressful adverse life events such as maternal separation severely impacts the development of the nervous system. Using immunohistochemistry, quantitative PCR and Western blot approaches, we found that alpha6 subunit-containing GABAA receptors (Gabra6-containing GABAA Rs) were expressed on hippocampal interneurons of adolescent rats. Maternal separation stress (MS) from postnatal day 2 to15 significantly reduced Gabra6 expression and provoked depressive behaviors such as anhedonia. Furosemide, the selective antagonist of Gabra6-containing GABAARs, strongly increased peak amplitude of evoked IPSCs at CA3-CA1 synapses and the frequency of miniature IPSPs recorded from CA1 pyramidal cells in naive control animals, and this effect was occluded in MS animals. Knockdown of Gabra6 expression in hippocampus mimicked furosemide's effect and was sufficient to produce similar depressive symptoms that were observed in MS animals. These results indicate that the Gabra6-containing GABAA R is a key modulator of hippocampal synaptic transmission and likely plays a crucial role in the pathophysiology of maternal separation-induced depression.

  8. Molecular cloning, structural analysis and tissue expression of protein phosphatase 3 catalytic subunit alpha isoform (PPP3CA) gene in Tianfu goat muscle.

    Science.gov (United States)

    Wan, Lu; Ma, Jisi; Xu, Gangyi; Wang, Daihua; Wang, Nianlu

    2014-02-07

    Calcineurin, a Ca(2+)/calmodulin-dependent protein phosphatase, plays a critical role in controlling skeletal muscle fiber type. However, little information is available concerning the expression of calcineurin in goat. Therefore, protein phosphatase 3 catalytic subunit alpha isoform (PPP3CA) gene, also called calcineurin Aα, was cloned and its expression characterized in Tianfu goat muscle. Real time quantitative polymerase chain reaction (RT-qPCR) analyses revealed that Tianfu goat PPP3CA was detected in cardiac muscle, biceps femoris muscle, abdominal muscle, longissimus dors muscle, and soleus muscle. High expression levels were found in biceps femoris muscle, longissimus muscle and abdominal muscle (p muscle and soleus muscle (p > 0.05). In addition, the spatial-temporal mRNA expression levels showed different variation trends in different muscles with the age of the goats. Western blotting further revealed that PPP3CA protein was expressed in the above-mentioned tissues, with the highest level in biceps femoris muscle, and the lowest level in soleus muscle. In this study, we isolated the full-length coding sequence of Tianfu goat PPP3CA gene, analyzed its structure, and investigated its expression in different muscle tissues from different age stages. These results provide a foundation for understanding the function of the PPP3CA gene in goats.

  9. Two novel functional mutations in the Na+,K+-ATPase alpha2-subunit ATP1A2 gene in patients with familial hemiplegic migraine and associated neurological phenotypes.

    Science.gov (United States)

    Castro, M-J; Nunes, B; de Vries, B; Lemos, C; Vanmolkot, K R J; van den Heuvel, J J M W; Temudo, T; Barros, J; Sequeiros, J; Frants, R R; Koenderink, J B; Pereira-Monteiro, J M; van den Maagdenberg, A M J M

    2008-01-01

    Mutations in the ATP1A2 gene, encoding the alpha2-subunit of the Na+,K+-ATPase, are associated with familial hemiplegic migraine type 2. The majority of ATP1A2 mutations were reported in patients with hemiplegic migraine without any additional neurological findings. Here, we report on two novel ATP1A2 mutations that were identified in two Portuguese probands with hemiplegic migraine and interesting additional clinical features. The proband's of family 1 (with a V362E mutation) had mood alterations, classified as a borderline personality. The proband in family 2 (with a P796S mutation) had mild mental impairment, in addition to hemiplegic migraine; more severe mental retardation was observed in his brother, who also had hemiplegic migraine and carried the same mutation. Cell-survival assays clearly showed abnormal functioning of mutant Na+,K+-ATPase, indicating that both ATP1A2 mutants are disease causing. Additionally, our results suggest a possible causal relationship of the ATP1A2 mutations with the complex clinical phenotypes observed in the probands.

  10. Interaction of the heterotrimeric G protein alpha subunit SSG-1 of Sporothrix schenckii with proteins related to stress response and fungal pathogenicity using a yeast two-hybrid assay

    Directory of Open Access Journals (Sweden)

    González-Méndez Ricardo

    2010-12-01

    Full Text Available Abstract Background Important biological processes require selective and orderly protein-protein interactions at every level of the signalling cascades. G proteins are a family of heterotrimeric GTPases that effect eukaryotic signal transduction through the coupling of cell surface receptors to cytoplasmic effector proteins. They have been associated with growth and pathogenicity in many fungi through gene knock-out studies. In Sporothrix schenckii, a pathogenic, dimorphic fungus, we previously identified a pertussis sensitive G alpha subunit, SSG-1. In this work we inquire into its interactions with other proteins. Results Using the yeast two-hybrid technique, we identified protein-protein interactions between SSG-1 and other important cellular proteins. The interactions were corroborated using co-immuneprecipitation. Using these techniques we identified a Fe/Mn superoxide dismutase (SOD, a glyceraldehyde-3-P dehydrogenase (GAPDH and two ion transport proteins, a siderophore-iron transporter belonging to the Major Facilitator Superfamily (MFS and a divalent-cation transporter of the Nramp (natural resistance-associated macrophage protein family as interacting with SSG-1. The cDNA's encoding these proteins were sequenced and bioinformatic macromolecular sequence analyses were used for the correct classification and functional assignment. Conclusions This study constitutes the first report of the interaction of a fungal G alpha inhibitory subunit with SOD, GAPDH, and two metal ion transporters. The identification of such important proteins as partners of a G alpha subunit in this fungus suggests possible mechanisms through which this G protein can affect pathogenicity and survival under conditions of environmental stress or inside the human host. The two ion transporters identified in this work are the first to be reported in S. schenckii and the first time they are identified as interacting with fungal G protein alpha subunits. The association

  11. MASH-II: More Planetary Nebulae from the AAO/UKST H\\alpha Survey

    CERN Document Server

    Miszalski, B; Acker, A; Birkby, J L; Frew, D J; Kovacevic, A

    2007-01-01

    We present a supplement to the Macquarie/AAO/Strasbourg H$\\alpha$ planetary nebulae (PNe) catalogue (MASH), which we denote MASH-II. The supplement consists of over 300 true, likely and possible new Galactic PNe found after re-examination of the entire AAO/UKST H$\\alpha$ survey of the southern Galactic Plane in digital form. We have spectroscopically confirmed over 240 of these new candidates as bona-fide PNe and we include other high quality candidates awaiting spectroscopic confirmation as possible PNe. These latest discoveries largely comprise two distinct groups: small, star-like or moderately resolved PNe at one end and mostly large, extremely low surface brightness PNe at the other. Neither group were easy to discover from simple visual scrutiny of the original survey exposures as for MASH but were relatively straightforward to uncover from the digital images via application of semi-automated discovery techniques. We suspect the few PNe still hidden in the H$\\alpha$ survey will lie outside our search cr...

  12. GalICS II: the [alpha/Fe]-mass relation in elliptical galaxies

    CERN Document Server

    Pipino, A; Thomas, D; Silk, J; Kaviraj, S

    2008-01-01

    We aim at reproducing the mass- and sigma-[alpha/Fe] relations in the stellar populations of early-type galaxies by means of a cosmologically motivated assembly history for the spheroids. We implement a detailed treatment for the chemical evolution of H, He, O and Fe in GalICS, a semi-analytical model for galaxy formation which successfully reproduces basic low- and high-redshift galaxy properties. The contribution of supernovae (both type Ia and II) as well as low- and intermediate-mass stars to chemical feedback are taken into account. We find that this chemically improved GalICS does not produce the observed mass- and sigma-[alpha/Fe] relations. The slope is too shallow and scatter too large, in particular in the low and intermediate mass range. The model shows significant improvement at the highest masses and velocity dispersions, where the predicted [alpha/Fe] ratios are now marginally consistent with observed values. We show that this result comes from the implementation of AGN (plus halo) quenching of ...

  13. Versatility of the carboxy-terminal domain of the alpha subunit of RNA polymerase in transcriptional activation: use of the DNA contact site as a protein contact site for MarA.

    Science.gov (United States)

    Dangi, Bindi; Gronenborn, Angela M; Rosner, Judah L; Martin, Robert G

    2004-10-01

    The transcriptional activator, MarA, interacts with RNA polymerase (RNAP) to activate promoters of the mar regulon. Here, we identify the interacting surfaces of MarA and of the carboxy-terminal domain of the alpha subunit of RNAP (alpha-CTD) by NMR-based chemical shift mapping. Spectral changes were monitored for a MarA-DNA complex upon titration with alpha-CTD, and for alpha-CTD upon titration with MarA-DNA. The mapping results were confirmed by mutational studies and retention chromatography. A model of the ternary complex shows that alpha-CTD uses a '265-like determinant' to contact MarA at a surface distant from the DNA. This is unlike the interaction of alpha-CTD with the CRP or Fis activators where the '265 determinant' contacts DNA while another surface of the same alpha-CTD molecule contacts the activator. These results reveal a new versatility for alpha-CTD in transcriptional activation.

  14. HH 666: Different kinematics from H{\\alpha} and [Fe II] emission provide a missing link between jets and outflows

    CERN Document Server

    Reiter, Megan; Kiminki, Megan M; Bally, John

    2015-01-01

    HH 666 is an externally irradiated protostellar outflow in the Carina Nebula for which we present new near-IR [Fe II] spectra obtained with the FIRE spectrograph at Magellan Observatory. Earlier H{\\alpha} and near-IR [Fe II] imaging revealed that the two emission lines trace substantially different morphologies in the inner ~40" of the outflow. H{\\alpha} traces a broad cocoon that surrounds the collimated [Fe II] jet that extends throughout the parent dust pillar. New spectra show that this discrepancy extends to their kinematics. Near-IR [Fe II] emission traces steady, fast velocities of +/- 200 km/s from the eastern and western limbs of the jet. We compare this to a previously published H{\\alpha} spectrum that reveals a Hubble-flow velocity structure near the jet-driving source. New, second-epoch HST/ACS H{\\alpha} images reveal the lateral spreading of the H{\\alpha} outflow lobe away from the jet axis. H{\\alpha} proper motions also indicate a sudden increase in the mass-loss rate ~1000 yr ago, while steady ...

  15. A new sodium channel alpha-subunit gene (Scn9a) from Schwann cells maps to the Scn1a, Scn2a, Scn3a cluster of mouse chromosome 2.

    Science.gov (United States)

    Beckers, M C; Ernst, E; Belcher, S; Howe, J; Levenson, R; Gros, P

    1996-08-15

    We have used a total of 27 AXB/BXA recombinant inbred mouse strains to determine the chromosomal location of a newly identified gene encoding an alpha-subunit isoform of the sodium channel from Schwann cells, Scn9a. Linkage analysis established that Scn9a mapped to the proximal segment of mouse chromosome 2. The segregation of restriction fragment length polymorphisms in 145 progeny from a Mus spretus x C57BL/6J backcross indicates that Scn9a is very tightly linked to Scn1a (gene encoding the type I sodium channel alpha-subunit of the brain) and forms part of a cluster of four Scna genes located on mouse chromosome 2.

  16. A new sodium channel {alpha}-subunit gene (Scn9a) from Schwann cells maps to the Scn1a, Scn2a, Scn3a cluster of mouse chromosome 2

    Energy Technology Data Exchange (ETDEWEB)

    Beckers, M.C.; Ernst, E.; Gros, P. [McGill Univ., Montreal (Canada)

    1996-08-15

    We have used a total of 27 AXB/BXA recombinant inbred mouse strains to determine the chromosomal location of a newly identified gene encoding an {alpha}-subunit isoform of the sodium channel from Schwann cells, Scn9a. Linkage analysis established that Scn9a mapped to the proximal segment of mouse chromosome 2. The segregation of restriction fragment length polymorphisms in 145 progeny from a Mus spretus x C57BL/6J backcross indicates that Scn9a is very tightly linked to Scn1a (gene encoding the type I sodium channel {alpha}-subunit of the brain) and forms part of a cluster of four Scna genes located on mouse chromosome 2. 17 refs., 1 fig., 3 tabs.

  17. Platelet cytosolic 44-kDa protein is a substrate of cholera toxin-induced ADP-ribosylation and is not recognized by antisera against the. alpha. subunit of the stimulatory guanine nucleotide-binding regulatory protein

    Energy Technology Data Exchange (ETDEWEB)

    Molina Y Vedia, L.M.; Reep, B.R.; Lapetina, E.G. (Burroughs Wellcome Co., Research Triangle Park, NC (USA))

    1988-08-01

    ADP-ribosylation induced by cholera toxin and pertussis toxin was studied in particulate and cytosolic fractions of human platelets. Platelets were disrupted by a cycle of freezing and thawing in the presence of a hyposmotic buffer containing protease inhibitors. In both fractions, the A subunit of cholera toxin ADP-ribosylates two proteins with molecular masses of 42 and 44 kDa, whereas pertussis toxin ADP-ribosylates a 41-kDa polypeptide. Two antisera against the {alpha} subunit of the stimulatory guanine nucleotide-binding regulatory protein recognize only the 42-kDa polypeptide. Cholera toxin-induced ADP-ribosylation of the 42- and 44-kDa proteins is reduced by pretreatment of platelets with iloprost, a prostacyclin analog. The 44-kDa protein, which is substrate of cholera toxin, could be extracted completely from the membrane and recovered in the cytosolic fraction when the cells were disrupted by Dounce homogenization and the pellet was extensively washed. A 44-kDa protein can also be labeled with 8-azidoguanosine 5{prime}-({alpha}-{sup 32}P)triphosphate in the cytosol and membranes. These finding indicate that cholera and pertussis toxins produced covalent modifications of proteins present in particulate and cytosolic platelet fractions. Moreover, the 44-kDa protein might be an {alpha} subunit of a guanine nucleotide-binding regulatory protein that is not recognized by available antisera.

  18. Gene targeting of CK2 catalytic subunits.

    Science.gov (United States)

    Seldin, David C; Lou, David Y; Toselli, Paul; Landesman-Bollag, Esther; Dominguez, Isabel

    2008-09-01

    Protein kinase CK2 is a highly conserved and ubiquitous serine-threonine kinase. It is a tetrameric enzyme that is made up of two regulatory CK2beta subunits and two catalytic subunits, either CK2alpha/CK2alpha, CK2alpha/CK2alpha', or CK2alpha'/CK2alpha'. Although the two catalytic subunits diverge in their C termini, their enzymatic activities are similar. To identify the specific function of the two catalytic subunits in development, we have deleted them individually from the mouse genome by homologous recombination. We have previously reported that CK2alpha' is essential for male germ cell development, and we now demonstrate that CK2alpha has an essential role in embryogenesis, as mice lacking CK2alpha die in mid-embryogenesis, with cardiac and neural tube defects.

  19. Effect of recombinant alpha interferon on NK and ADCC function in lung cancer patients: results from a phase II trial

    DEFF Research Database (Denmark)

    Hokland, P; Hokland, M; Olesen, B K

    1985-01-01

    During a phase II trial of recombinant IFN-alpha given in doses of 50 X 10(6) units/m2 three times per week to lung cancer patients, 13 patients were evaluated longitudinally in NK and ADCC assays and in immunofluorescence tests enumerating the number of cells reactive with the new N901 NK-cell a....... These data are discussed in relation to other clinical trials using leukocyte or recombinant IFN-alpha. Udgivelsesdato: 1984 Fall...

  20. Evaluation of Zinc-alpha-2-Glycoprotein and Proteasome Subunit beta-Type 6 Expression in Prostate Cancer Using Tissue Microarray Technology.

    LENUS (Irish Health Repository)

    2010-07-23

    Prostate cancer (CaP) is a significant cause of illness and death in males. Current detection strategies do not reliably detect the disease at an early stage and cannot distinguish aggressive versus nonaggressive CaP leading to potential overtreatment of the disease and associated morbidity. Zinc-alpha-2-glycoprotein (ZAG) and proteasome subunit beta-Type 6 (PSMB-6) were found to be up-regulated in the serum of CaP patients with higher grade tumors after 2-dimensional difference gel electrophoresis analysis. The aim of this study was to investigate if ZAG and PSMB-6 were also overexpressed in prostatic tumor tissue of CaP patients. Immunohistochemical analysis was performed on CaP tissue microarrays with samples from 199 patients. Confirmatory gene expression profiling for ZAG and PSMB-6 were performed on 4 cases using Laser Capture Microdissection and TaqMan real-time polymerase chain reaction. ZAG expression in CaP epithelial cells was inversely associated with Gleason grade (benign prostatic hyperplasia>G3>G4\\/G5). PSMB-6 was not expressed in either tumor or benign epithelium. However, strong PSMB-6 expression was noted in stromal and inflammatory cells. Our results indicate ZAG as a possible predictive marker of Gleason grade. The inverse association between grade and tissue expression with a rising serum protein level is similar to that seen with prostate-specific antigen. In addition, the results for both ZAG and PSMB-6 highlight the challenges in trying to associate the protein levels in serum with tissue expression.

  1. GlyT1 Inhibitor NFPS Exerts Neuroprotection via GlyR Alpha1 Subunit in the Rat Model of Transient Focal Cerebral Ischaemia and Reperfusion

    Directory of Open Access Journals (Sweden)

    Baosheng Huang

    2016-05-01

    Full Text Available Background/Aims: Glycine is a strychnine-sensitive inhibitory neurotransmitter in the central nervous system (CNS, especially in the spinal cord, brainstem, and retina. The objective of the present study was to investigate the potential neuroprotective effects of GlyT1 inhibitor N [3-(4'-fluorophenyl-3-(4'-phenylphenoxy propyl] sarcosine (NFPS in the rat model of experimental stroke. Methods: In vivo ischaemia was induced by transient middle cerebral artery occlusion (tMCAO. The methods of Western Blotting, Nissl Staining and Morris water maze methods were applied to analyze the anti-ischaemia mechanism. Results: The results showed that high dose of NFPS (H-NFPS significantly reduced infarct volume, neuronal injury and the expression of cleaved caspase-3, enhanced Bcl-2/Bax, and improved spatial learning deficits which were administered three hours after transient middle cerebral artery occlusion (tMCAO induction in rats, while, low dose of NFPS (L-NFPS exacerbated the injury of ischaemia. These findings suggested that low and high dose of NFPS produced opposite effects. Importantly, it was demonstrated that H-NFPS-dependent neuronal protection was inverted by salicylate (Sal, a specific GlyR ɑ1 antagonist. Such effects could probably be attributed to the enhanced glycine level in both synaptic and extrasynaptic clefts and the subsequently altered extrasynaptic GlyRs and their subtypes. Conclusions: These data imply that GlyT1 inhibitor NFPS may be a novel target for clinical treatment of transient focal cerebral ischaemia and reperfusion which are associated with altered GlyR alpha 1 subunits.

  2. Alanine 101 and alanine 110 of the alpha subunit of Pseudomonas stutzeri OX1 toluene-o-xylene monooxygenase influence the regiospecific oxidation of aromatics.

    Science.gov (United States)

    Vardar, Gönül; Tao, Ying; Lee, Jintae; Wood, Thomas K

    2005-12-05

    Saturation mutagenesis was used to generate 10 mutants of toluene-o-xylene monooxygenase (ToMO) at alpha subunit (TouA) positions A101 and A110: A101G, A101I, A101M, A101VE, A101V, A110G, A110C, A110S, A110P, and A110T; by testing the substrates toluene, o-cresol, m-cresol, p-cresol, phenol, naphthalene, o-methoxyphenol, m-methoxyphenol, p-methoxyphenol, o-xylene, and nitrobenzene, these positions were found to influence the regiospecific oxidation of aromatics. For example, compared to wild-type ToMO, TouA variant A101V produced threefold more 3-methoxycatechol from m-methoxyphenol as well as produced methylhydroquinone from o-cresol whereas wild-type ToMO did not. Similarly, variant A110C synthesized 1.8-fold more o-cresol from toluene and 1.8-fold more 3-methoxycatechol from m-methoxyphenol, and variant A110G synthesized more m-nitrophenol and twofold less p-nitrophenol from nitrobenzene. The A101V and A110C mutations did not affect the rate of reaction with the natural substrate toluene, so the variants had high activity. This is the first report that these or analogous residues influence the catalysis with this class of enzymes. Wild-type ToMO was found to oxidize o-methoxyphenol to methoxyhydroquinone (60%) and 4-methoxyresorcinol (40%), m-methoxyphenol to 4-methoxycatechol (96%) and 3-methoxycatechol (4%), and p-methoxyphenol to 4-methoxycatechol (100%). (c) 2005 Wiley Periodicals, Inc.

  3. Phosphatidyl-inositol-3-kinase alpha catalytic subunit mutation and response to neoadjuvant endocrine therapy for estrogen receptor positive breast cancer

    Science.gov (United States)

    Ellis, Matthew J; Lin, Li; Crowder, Robert; Tao, Yu; Hoog, Jeremy; Snider, Jacqueline; Davies, Sherri; DeSchryver, Katherine; Evans, Dean B; Steinseifer, Jutta; Bandaru, Raj; Liu, WeiHua; Gardner, Humphrey; Semiglazov, Vladimir; Watson, Mark; Hunt, Kelly; Olson, John; Baselga, José

    2010-01-01

    Background Mutations in the alpha catalytic subunit of phosphoinositol-3-kinase (PIK3CA) occur in ~30% of ER positive breast cancers. We therefore sought to determine the impact of PIK3CA mutation on response to neoadjuvant endocrine therapy. Methods Exon 9 (helical domain - HD) and Exon 20 (kinase domain- KD) mutations in PIK3CA were determined samples from four neoadjuvant endocrine therapy trials. Interactions with clinical, pathological and biomarker response parameters were examined. Results A weak negative interaction between PIK3CA mutation status and clinical response to neoadjuvant endocrine treatment was detected (N=235 P=<0.05), but not with treatment-induced changes in Ki67-based proliferation index (N=418). Despite these findings, PIK3CA KD mutation was a favorable prognostic factor for relapse-free survival (RFS log rank P=0.02) in the P024 trial (N=153). The favorable prognostic effect was maintained in a multivariable analysis (N=125) that included the preoperative prognostic index (PEPI), an approach to predicting RFS based on post neoadjuvant endocrine therapy pathological stage, ER and Ki67 levels (HR for no PIK3CA KD mutation, 14, CI 1.9–105 P=0.01). Conclusion PIK3CA mutation status did not strongly interact with neoadjuvant endocrine therapy responsiveness in estrogen receptor positive breast cancer. Nonetheless, as with other recent studies, a favorable interaction between PIK3CA kinase domain mutation and prognosis was detected. The mechanism for the favorable prognostic impact of PIK3CA mutation status therefore remains unexplained. PMID:19844788

  4. Three-dimensional localization of the α and β subunits and of the II-III loop in the skeletal muscle L-type Ca2+ channel.

    Science.gov (United States)

    Szpyt, John; Lorenzon, Nancy; Perez, Claudio F; Norris, Ethan; Allen, Paul D; Beam, Kurt G; Samsó, Montserrat

    2012-12-21

    The L-type Ca(2+) channel (dihydropyridine receptor (DHPR) in skeletal muscle acts as the voltage sensor for excitation-contraction coupling. To better resolve the spatial organization of the DHPR subunits (α(1s) or Ca(V)1.1, α(2), β(1a), δ1, and γ), we created transgenic mice expressing a recombinant β(1a) subunit with YFP and a biotin acceptor domain attached to its N- and C- termini, respectively. DHPR complexes were purified from skeletal muscle, negatively stained, imaged by electron microscopy, and subjected to single-particle image analysis. The resulting 19.1-Å resolution, three-dimensional reconstruction shows a main body of 17 × 11 × 8 nm with five corners along its perimeter. Two protrusions emerge from either face of the main body: the larger one attributed to the α(2)-δ1 subunit that forms a flexible hook-shaped feature and a smaller protrusion on the opposite side that corresponds to the II-III loop of Ca(V)1.1 as revealed by antibody labeling. Novel features discernible in the electron density accommodate the atomic coordinates of a voltage-gated sodium channel and of the β subunit in a single docking possibility that defines the α1-β interaction. The β subunit appears more closely associated to the membrane than expected, which may better account for both its role in localizing the α(1s) subunit to the membrane and its suggested role in excitation-contraction coupling.

  5. Beta 2 subunit-containing nicotinic receptors mediate acute nicotine-induced activation of calcium/calmodulin-dependent protein kinase II-dependent pathways in vivo.

    Science.gov (United States)

    Jackson, K J; Walters, C L; Damaj, M I

    2009-08-01

    Nicotine is the addictive component of tobacco, and successful smoking cessation therapies must address the various processes that contribute to nicotine addiction. Thus, understanding the nicotinic acetylcholine receptor (nAChR) subtypes and subsequent molecular cascades activated after nicotine exposure is of the utmost importance in understanding the progression of nicotine dependence. One possible candidate is the calcium/calmodulin-dependent protein kinase II (CaMKII) pathway. Substrates of this kinase include the vesicle-associated protein synapsin I and the transcription factor cAMP response element-binding protein (CREB). The goal of these studies was to examine these postreceptor mechanisms after acute nicotine treatment in vivo. We first show that administration of nicotine increases CaMKII activity in the ventral tegmental area (VTA), nucleus accumbens (NAc), and amygdala. In beta2 nAChR knockout (KO) mice, nicotine does not induce an increase in kinase activity, phosphorylated (p)Synapsin I, or pCREB. In contrast, alpha7 nAChR KO mice show nicotine-induced increases in CaMKII activity and pCREB, similar to their wild-type littermates. Moreover, we show that when animals are pretreated with the CaMKII inhibitors 4-[(2S)-2-[(5-isoquinolinylsulfonyl) methylamino]-3-oxo-3-(4-phenyl-1-piperazinyl)propyl]phenyl isoquinolinesulfonic acid ester (KN-62) and N-[2-[[[3-(4-chlorophenyl)-2 propenyl]methylamino]methyl]phenyl]-N-(2-hydroxyethyl)-4-methoxybenzenesulphonamide (KN-93), nicotine-induced increase in the kinase activity and pCREB was attenuated in the VTA and NAc, whereas pretreatment with (2-[N-(4-methoxybenzenesulfonyl)]amino-N-(4-chlorocinnamyl)-N-methylbenzylamine, phosphate) (KN-92), the inactive analog, did not alter the nicotine-induced increase in pCREB. Taken together, these data suggest that the nicotine-induced increase in CaMKII activity may correlate with the nicotine-induced increase in pSynapsin I and pCREB in the VTA and NAc via beta2

  6. Phaeophytins from Thyrsacanthus ramosissimus Moric. with inhibitory activity on human DNA topoisomerase II-{alpha}

    Energy Technology Data Exchange (ETDEWEB)

    Cabral, Analucia Guedes Silveira; Tenorio-Souza, Fabio Henrique; Moura, Marcelo Dantas; Mota, Sabrina Gondim Ribeiro; Silva Lins, Antonio Claudio da; Dias, Celidarque da Silva; Barbosa-Filho, Jose Maria [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Dept. de Ciencias Frmaceuticas; Giulietti, Ana Maria [Universidade Estadual de Feira de Santana, Feira de Santana, BA (Brazil). Dept. de Ciencias Biologicas; Silva, Tania Maria Sarmento da [Universidade Federal Rural de Pernambuco, Recife, PE (Brazil). Dept. de Ciencias Moleculares; Santos, Creusioni Figueredo dos, E-mail: jbarbosa@ltf.ufpb.br [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Dept. de Biologia Molecular

    2012-07-01

    Our study reports the extraction and isolation of a new phaeophytin derivative 15{sup 1}-hydroxy-(15{sup 1}-S)-porphyrinolactone, designated anamariaine (1) herein, isolated from the chloroform fraction of aerial parts of Thyrsacanthus ramosissimus Moric. along with the known 15{sup 1}-ethoxy-(15{sup 1}-S)-porphyrinolactone (2). These compounds were identified by usual spectroscopic methods. Both compounds were subjected to in vitro (inhibitory activity) tests by means of supercoiled DNA relaxation techniques and were shown to display inhibitory activity against human DNA topoisomerase II-{alpha} at 50 {mu}M. Interconversion of these two pigments under the mild conditions of the isolation techniques should be highly unlikely but cannot be entirely ruled out. (author)

  7. Diamagnetic anisotropy and orientation of alpha helix in frog rhodopsin and meta II intermediate.

    Science.gov (United States)

    Chabre, M

    1978-01-01

    The diamagnetic anisotropy of retinal rod outer segments, and its variation upon bleaching, have been measured with a rotating field device. A large molar diamagnetic asymmetry is found for rhodopsin. This cannot be explained by an anisotropy of the aromatic side chains of the protein, nor by the orientation of the retinal chromophore. However, it can be accounted for by an orientation perpendicular to the disc membrane of a major proportion of the alpha-helical segments of the protein. Upon bleaching a decrease of 9 +/- 2% of the diamagnetic asymmetry is observed when going to the meta II intermediate. This change is not mainly due to a reorientation of the retinal, since it is practically insensitive to detachment of the chromophore by addition of NH2OH. Comparison with recent UV linear dichroism results indicate that it may be due to the rotation of a trytophan residue in the bleaching sequence. PMID:310121

  8. Chromospheric Sunspot Oscillations in H-alpha and Ca II 8542A

    CERN Document Server

    Maurya, Ram Ajor; Park, Hyungmin; Yang, Heesu; Song, Donguk; Cho, Kyuhyoun

    2013-01-01

    We study chromospheric oscillations including umbral flashes and running penumbral waves in a sunspot of active region (AR) using scanning spectroscopy in H-alpha and Ca II 8542A, with the Fast Imaging Solar Spectrograph (FISS) at the 1.6 meter New Solar Telescope at Big Bear Solar Observatory. A bisector method is applied to spectral observations to construct chromospheric Doppler velocity maps. Temporal sequence analysis of these shows enhanced high-frequency oscillations inside the sunspot umbra in both lines. Their peak frequency gradually decreases outward from the umbra. The oscillation power is found to be associated with magnetic-field strength and inclination, with different relationships in different frequency bands.

  9. Expression of 10 GABA(A) receptor subunit messenger RNAs in the motor-related thalamic nuclei and basal ganglia of Macaca mulatta studied with in situ hybridization histochemistry.

    Science.gov (United States)

    Kultas-Ilinsky, K; Leontiev, V; Whiting, P J

    1998-07-01

    In situ hybridization histochemistry technique with [35S]UTP-labelled riboprobes was used to study the expression pattern of 10 GABA(A) receptor subunit messenger RNAs in the basal ganglia and motor thalamic nuclei of rhesus monkey. Human transcripts were used for the synthesis of alpha2, alpha4, beta2, beta3, gamma1 and delta subunit messenger RNA probes. Rat complementary DNAs were used for generating alpha1, alpha3, beta1 and gamma2 subunit messenger RNA probes. Nigral, pallidal and cerebellar afferent territories in the ventral tier thalamic nuclei all expressed alpha1, alpha2, alpha3, alpha4, beta1, beta2, beta3, delta and gamma2 subunit messenger RNAs but at different levels. Each intralaminar nucleus displayed its own unique expression pattern. In the thalamus, gamma1 subunit messenger RNA was detected only in the parafascicular nucleus. Comparison of the expression patterns with the known organization of GABA(A) connections in thalamic nuclei suggests that (i) the composition of the receptor associated with reticulothalamic synapses, except for those in the intralaminar nuclei, may be alpha1alpha4beta2delta, (ii) receptors of various other subunit compositions may operate in the local GABAergic circuits, and (iii) the composition of receptors at nigro- and pallidothalamic synapses may differ, with those at nigrothalamic probably containing beta1 and gamma2 subunits. In the medial and lateral parts of the globus pallidus, the subthalamic nucleus and the substantia nigra pars reticularis, the alpha1, beta2 and gamma2 messenger RNAs were co-expressed at a high level suggesting that this subunit composition was associated with all GABAergic synapses in the direct and indirect striatal output pathways. Various other subunit messenger RNAs were also expressed but at a lower level. In the substantia nigra pars compacta the most highly expressed messenger RNAs were alpha3, alpha4 and beta3; all other subunit messenger RNAs studied, except for gamma1, alpha1 and

  10. The anxioselective agent 7-(2-chloropyridin-4-yl)pyrazolo-[1,5-a]-pyrimidin-3-yl](pyridin-2-yl)methanone (DOV 51892) is more efficacious than diazepam at enhancing GABA-gated currents at alpha1 subunit-containing GABAA receptors.

    Science.gov (United States)

    Popik, Piotr; Kostakis, Emmanuel; Krawczyk, Martyna; Nowak, Gabriel; Szewczyk, Bernadeta; Krieter, Philip; Chen, Zhengming; Russek, Shelley J; Gibbs, Terrell T; Farb, David H; Skolnick, Phil; Lippa, Arnold S; Basile, Anthony S

    2006-12-01

    Studies using mice with point mutations of GABA(A) receptor alpha subunits suggest that the sedative and anxiolytic properties of 1,4-benzodiazepines are mediated, respectively, by GABA(A) receptors bearing the alpha(1) and alpha(2) subunits. This hypothesis predicts that a compound with high efficacy at GABA(A) receptors containing the alpha(1) subunit would produce sedation, whereas an agonist acting at alpha(2) subunit-containing receptors (with low or null efficacy at alpha(1)-containing receptors) would be anxioselective. Electrophysiological studies using recombinant GABA(A) receptors expressed in Xenopus oocytes indicate that maximal potentiation of GABA-stimulated currents by the pyrazolo-[1,5-a]-pyrimidine, DOV 51892, at alpha(1)beta(2)gamma(2S) constructs of the GABA(A) receptor was significantly higher (148%) than diazepam. In contrast, DOV 51892 was considerably less efficacious and/or potent than diazepam in enhancing GABA-stimulated currents mediated by constructs containing alpha(2), alpha(3), or alpha(5) subunits. In vivo, DOV 51892 increased punished responding in the Vogel conflict test, an effect blocked by flumazenil, and increased the percentage of time spent in the open arms of the elevated plus-maze. However, DOV 51892 had no consistent effects on motor function or muscle relaxation at doses more than 1 order of magnitude greater than the minimal effective anxiolytic dose. Although the mutant mouse data predict that the high-efficacy potentiation of GABA(A1a) receptor-mediated currents by DOV 51892 would be sedating, behavioral studies demonstrate that DOV 51892 is anxioselective, indicating that GABA potentiation mediated by alpha(1) subunit-containing GABA(A) receptors may be neither the sole mechanism nor highly predictive of the sedative properties of benzodiazepine recognition site modulators.

  11. Structural motifs and potential sigma homologies in the large subunit of human general transcription factor TFIIE.

    Science.gov (United States)

    Ohkuma, Y; Sumimoto, H; Hoffmann, A; Shimasaki, S; Horikoshi, M; Roeder, R G

    1991-12-05

    The general transcription factor TFIIE has an essential role in eukaryotic transcription initiation together with RNA polymerase II and other general factors. Human TFIIE consists of two subunits of relative molecular mass 57,000 (TFIIE-alpha) and 34,000 (TFIIE-beta) and joins the preinitiation complex after RNA polymerase II and TFIIF. Here we report the cloning and structure of a complementary DNA encoding a functional human TFIIE-alpha. TFIIE-alpha is necessary for transcription initiation together with TFIIE-beta, and recombinant TFIIE-alpha can fully replace the natural subunit in an in vitro transcription assay. The sequence contains several interesting structural motifs (leucine repeat, zinc finger and helix-turn-helix) and sequence similarities to bacterial sigma factors that suggest direct involvement in the regulation of transcription initiation.

  12. Vibron-polaron in alpha-helices. II. Two-vibron bound states

    CERN Document Server

    Falvo, C; Falvo, Cyril; Pouthier, Vincent

    2005-01-01

    The two-vibron dynamics associated to amide-I vibrations in a 3D $\\alpha$-helix is described according to a generalized Davydov model. The helix is modeled by three spines of hydrogen-bonded peptide units linked via covalent bonds. It is shown that the two-vibron energy spectrum supports both a two-vibron free states continuum and two kinds of bound states, called TVBS-I and TVBS-II, connected to the trapping of two vibrons onto the same amide-I mode and onto two nearest neighbor amide-I modes belonging to the same spine, respectively. At low temperature, non vanishing interspine hopping constants yield a three dimensional nature of both TVBS-I and TVBS-II which the wave functions extend over the three spines of the helix. At biological temperature, the pairs are confined in a given spine and exhibit the same features as the bound states described within a one-dimensional model. The interplay between the temperature and the 3D nature of the helix is also responsible for the occurrence of a third bound state c...

  13. HeII emission in Lyman-alpha nebulae: AGN or cooling radiation?

    CERN Document Server

    Scarlata, C; Teplitz, H I; Bridge, C; Francis, P; Palunas, P; Siana, B; Williger, G M; Woodgate, B

    2009-01-01

    We present a study of an extended Lyman-alpha (Lya) nebula located in a known overdensity at z~2.38. The data include multiwavelength photometry covering the rest-frame spectral range from 0.1 to 250um, and deep optical spectra of the sources associated with the extended emission. Two galaxies are associated with the Lya nebula. One of them is a dust enshrouded AGN, while the other is a powerful starburst, forming stars at >~600 Msol/yr. We detect the HeII emission line at 1640A in the spectrum of the obscured AGN, but detect no emission from other highly ionized metals (CIV or NV) as is expected from an AGN. One scenario that simultaneously reproduces the width of the detected emission lines, the lack of CIV emission, and the geometry of the emitting gas, is that the HeII and the Lya emission are the result of cooling gas that is being accreted on the dark matter halo of the two galaxies, Ly1 and Ly2. Given the complexity of the environment associated with our Lya nebula it is possible that various mechanism...

  14. Electron/gamma and alpha backgrounds in CRESST-II Phase 2

    CERN Document Server

    Strauss, R; Bento, A; Bucci, C; Canonica, L; Erb, A; Feilitzsch, F v; Iachellini, N Ferreiro; Gorla, P; Gütlein, A; Hauff, D; Jochum, J; Kiefer, M; Kluck, H; Kraus, H; Lanfranchi, J -C; Loebell, J; Münster, A; Petricca, F; Potzel, W; Pröbst, F; Reindl, F; Roth, S; Rottler, K; Sailer, C; Schäffner, K; Schieck, J; Scholl, S; Schönert, S; Seidel, W; Sivers, M v; Stodolsky, L; Strandhagen, C; Tanzke, A; Uffinger, M; Ulrich, A; Usherov, I; Wawoczny, S; Willers, M; Wüstrich, M; Zöller, A

    2014-01-01

    The experiment CRESST-II aims at the detection of dark matter with scintillating CaWO$_4$ crystals operated as cryogenic detectors. Recent results on spin-independent WIMP-nucleon scattering from the CRESST-II Phase 2 allowed to probe a new region of parameter space for WIMP masses below 3$\\,$GeV/c$^2$. This sensitivity was achieved after background levels were reduced significantly. We present extensive background studies of a CaWO$_4$ crystal, called TUM40, grown at the Technische Universit\\"at M\\"unchen. The average beta/gamma rate of 3.44/[kg$\\,$keV$\\,$day] (1-40$\\,$keV) and the total intrinsic alpha activity from natural decay chains of $3.08\\pm0.04\\,$mBq/kg are the lowest reported for CaWO$_4$ detectors. Contributions of gamma lines resulting from cosmogenic activation, external X-rays and intrinsic beta emitters are investigated in detail.

  15. Saturation mutagenesis of Bradyrhizobium sp. BTAi1 toluene 4-monooxygenase at alpha-subunit residues proline 101, proline 103, and histidine 214 for regiospecific oxidation of aromatics.

    Science.gov (United States)

    Yanık-Yıldırım, K Cansu; Vardar-Schara, Gönül

    2014-11-01

    A novel toluene monooxygenase (TMO) six-gene cluster from Bradyrhizobium sp. BTAi1 having an overall 35, 36, and 38 % protein similarity with toluene o-xylene monooxygenase (ToMO) of Pseudomonas sp. OX1, toluene 4-monooxygenase (T4MO) of Pseudomonas mendocina KR1, and toluene-para-monooxygenase (TpMO) of Ralstonia pickettii PKO1, respectively, was cloned and expressed in Escherichia coli TG1, and its potential activity was investigated for aromatic hydroxylation and trichloroethylene (TCE) degradation. The natural substrate toluene was hydroxylated to p-cresol, indicating that the new toluene monooxygenase (T4MO·BTAi1) acts as a para hydroxylating enzyme, similar to T4MO and TpMO. Some shifts in regiospecific hydroxylations were observed compared to the other wild-type TMOs. For example, wild-type T4MO·BTAi1 formed catechol (88 %) and hydroquinone (12 %) from phenol, whereas all the other wild-type TMOs were reported to form only catechol. Furthermore, it was discovered that TG1 cells expressing wild-type T4MO·BTAi1 mineralized TCE at a rate of 0.67 ± 0.10 nmol Cl(-)/h/mg protein. Saturation and site directed mutagenesis were used to generate eight variants of T4MO·BTAi1 at alpha-subunit positions P101, P103, and H214: P101T/P103A, P101S, P101N/P103T, P101V, P103T, P101V/P103T, H214G, and H214G/D278N; by testing the substrates phenol, nitrobenzene, and naphthalene, positions P101 and P103 were found to influence the regiospecific oxidation of aromatics. For example, compared to wild type, variant P103T produced four fold more m-nitrophenol from nitrobenzene as well as produced mainly resorcinol (60 %) from phenol whereas wild-type T4MO·BTAi1 did not. Similarly, variants P101T/P103A and P101S synthesized more 2-naphthol and 2.3-fold and 1.6-fold less 1-naphthol from naphthalene, respectively.

  16. MiR-30e suppresses proliferation of hepatoma cells via targeting prolyl 4-hydroxylase subunit alpha-1 (P4HA1) mRNA

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Guoxing [State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin (China); Shi, Hui [State Key Laboratory of Medicinal Chemical Biology, Department of Biochemistry, College of Life Sciences, Nankai University, Tianjin (China); Li, Jiong; Yang, Zhe [State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin (China); Fang, Runping; Ye, Lihong [State Key Laboratory of Medicinal Chemical Biology, Department of Biochemistry, College of Life Sciences, Nankai University, Tianjin (China); Zhang, Weiying, E-mail: zhwybao@nankai.edu.cn [State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin (China); Zhang, Xiaodong, E-mail: zhangxd@nankai.edu.cn [State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin (China)

    2016-04-08

    Aberrant microRNA expression has been shown to be characteristic of many cancers. It has been reported that the expression levels of miR-30e are decreased in liver cancer tissues. However, the role of miR-30e in hepatocellular carcinoma remains poorly understood. In the present study, we investigated the significance of miR-30e in hepatocarcinogenesis. Bioinformatics analysis reveals a putative target site of miR-30e in the 3′-untranslated region (3′UTR) of prolyl 4-hydroxylase subunit alpha-1 (P4HA1) mRNA. Moreover, luciferase reporter gene assays verified that miR-30e directly targeted 3′UTR of P4HA1 mRNA. Then, we demonstrated that miR-30e was able to reduce the expression of P4HA1 at the levels of mRNA and protein using reverse transcription-polymerase chain reaction and Western blot analysis. Enforced expression of miR-30e suppressed proliferation of HepG2 cells by 5-ethynyl-2-deoxyuridine (EdU) assay and reduced colony formation of these cells by colony formation analysis. Conversely, anti-miR-30e enhanced the proliferation of hepatoma cells in vitro. Interestingly, the ectopic expression of P4HA1 could efficiently rescue the inhibition of cell proliferation mediated by miR-30e in HepG2 cells. Meanwhile, silencing of P4HA1 abolished the anti-miR-30e-induced proliferation of cells. Clinically, quantitative real-time PCR showed that miR-30e was down-regulated in liver tumor tissues relative to their peritumor tissues. The expression levels of miR-30e were negatively correlated to those of P4HA1 mRNA in clinical liver tumor tissues. Thus, we conclude that miR-30e suppresses proliferation of hepatoma cells through targeting P4HA1 mRNA. Our finding provides new insights into the mechanism of hepatocarcinogenesis. - Highlights: • P4HA1 is a novel target gene of miR-30e. • P4HA1 is increased in clinical HCC tissues. • MiR-30e is negatively correlated with P4HA1 in clinical HCC tissues. • MiR-30e suppresses the proliferation of HCC cells through

  17. A critical role for the S4-S5 intracellular loop in domain IV of the sodium channel alpha-subunit in fast inactivation.

    Science.gov (United States)

    McPhee, J C; Ragsdale, D S; Scheuer, T; Catterall, W A

    1998-01-09

    Na+ channel fast inactivation is thought to involve the closure of an intracellular inactivation gate over the channel pore. Previous studies have implicated the intracellular loop connecting domains III and IV and a critical IFM motif within it as the inactivation gate, but amino acid residues at the intracellular mouth of the pore required for gate closure and binding have not been positively identified. The short intracellular loops connecting the S4 and S5 segments in each domain of the Na+ channel alpha-subunit are good candidates for this role in the Na+ channel inactivation process. In this study, we used scanning mutagenesis to examine the role of the IVS4-S5 region in fast inactivation. Mutations F1651A, near the middle of the loop, and L1660A and N1662A, near the COOH-terminal end, substantially disrupted Na+ channel fast inactivation. The mutant F1651A conducted Na+ currents that decayed very slowly, while L1660A and N1662A had large sustained Na+ currents at the end of 30-ms depolarizing pulses. Inactivation of macroscopic Na+ currents was nearly abolished by the N1662A mutation and the combination of the F1651A/L1660A mutations. Single channel analysis revealed frequent reopenings for all three mutants during 40-ms depolarizing pulses, indicating a substantial impairment of the stability of the inactivated state compared with wild type (WT). The F1651A and N1662A mutants also had increased mean open times relative to WT, indicating a slowed rate of entry into the inactivated state. In addition to these effects on inactivation of open Na+ channels, mutants F1651A, L1660A, and N1662A also impaired fast inactivation of closed Na+ channels, as assessed from measurements of the maximum open probability of single channels. The peptide KIFMK mimics the IFM motif of the inactivation gate and provides a test of the effect of mutations on the hydrophobic interaction of this motif with the inactivation gate receptor. KIFMK restores fast inactivation of open

  18. Functional and molecular plasticity of gamma and alpha-1 GABAA receptor subunits in the dorsal motor nucleus of the vagus after experimentally-induced diabetes.

    Science.gov (United States)

    Boychuk, Carie R; Smith, Katalin Cs; Smith, Bret N

    2017-08-23

    Chronic experimentally-induced hyperglycemia augments subunit specific gamma-aminobutyric acid A (GABAA) receptor-mediated inhibition of parasympathetic preganglionic motor neurons in the dorsal motor nucleus of the vagus (DMV). However, the contribution of α1 or γ GABAA receptor subunits, which are ubiquitously expressed on central nervous system neurons, to this elevation in inhibitory tone have not been determined. This study investigated the effect of chronic hyperglycemia/hypoinsulinemia on α1- and γ-subunit specific GABAA receptor-mediated inhibition using electrophysiological recordings in vitro and quantitative (q)RT-PCR. DMV neurons from streptozotocin-treated mice demonstrated enhancement of both phasic and tonic inhibitory currents in response to application of the α1-subunit selective GABAA receptor positive allosteric modulator, zolpidem. Responses to low concentrations of the GABAA receptor antagonist, gabazine suggested an additional increased contribution of γ-subunit-containing receptors to tonic currents in DMV neurons. Consistent with the functional elevation in α1- and γ-subunit-dependent activity, transcription of both the α1- and γ2-subunits was increased in the dorsal vagal complex of streptozotocin-treated mice. Overall these findings suggest an increased sensitivity to both zolpidem and gabazine after several days of hyperglycemia/hypoinsulinemia, which could contribute to altered parasympathetic output from DMV neurons in diabetes. Copyright © 2017, Journal of Neurophysiology.

  19. Structural basis of transcription: alpha-amanitin-RNA polymerase II cocrystal at 2.8 A resolution.

    Science.gov (United States)

    Bushnell, David A; Cramer, Patrick; Kornberg, Roger D

    2002-02-05

    The structure of RNA polymerase II in a complex with the inhibitor alpha-amanitin has been determined by x-ray crystallography. The structure of the complex indicates the likely basis of inhibition and gives unexpected insight into the transcription mechanism.

  20. Human acid alpha-glucosidase from rabbit milk has therapeutic effect in mice with glycogen storage disease type II

    NARCIS (Netherlands)

    A.G.A. Bijvoet (Agnes); A.J.J. Reuser (Arnold); H. van Hirtum (Hans); M.A. Kroos (Marian); E.H. van de Kamp; O. Schoneveld; P. Visser (Pim); J.P. Brakenhoff (Just); M. Weggeman; E.J.J.M. van Corven (Emiel); A.T. van der Ploeg (Ans)

    1999-01-01

    textabstractPompe's disease or glycogen storage disease type II (GSDII) belongs to the family of inherited lysosomal storage diseases. The underlying deficiency of acid alpha-glucosidase leads in different degrees of severity to glycogen storage in heart, skeletal and s

  1. Structure-function of proteins interacting with the alpha1 pore-forming subunit of high voltage-activated calcium channel

    Directory of Open Access Journals (Sweden)

    Alan eNeely

    2014-06-01

    Full Text Available Openings of high-voltage-activated calcium channels lead to a transient increase in calcium concentration that in turn activate a plethora of cellular functions, including muscle contraction, secretion and gene transcription. To coordinate all these responses calcium channels form supramolecular assemblies containing effectors and regulatory proteins that couple calcium influx to the downstream signal cascades and to feedback elements. According to the original biochemical characterization of skeletal muscle Dihydropyridine receptors, high-voltage-activated calcium channels are multi-subunit protein complexes consisting of a pore-forming subunit (α1 associated with four additional polypeptide chains β, α2, δ and γ, often referred to as accessory subunits. Twenty-five years after the first purification of a high-voltage calcium channel, the concept of a flexible stoichiometry to expand the repertoire of mechanisms that regulate calcium channel influx has emerged. Several other proteins have been identified that associate directly with the α1-subunit, including calmodulin and multiple members of the small and large GTPase family. Some of these proteins only interact with a subset of α1-subunits and during specific stages of biogenesis. More strikingly, most of the α1-subunit interacting proteins, such as the β-subunit and small GTPases, regulate both gating and trafficking through a variety of mechanisms. Modulation of channel activity covers almost all biophysical properties of the channel. Likewise, regulation of the number of channels in the plasma membrane is performed by altering the release of the α1-subunit from the endoplasmic reticulum, by reducing its degradation or enhancing its recycling back to the cell surface. In this review, we discuss the structural basis, interplay and functional role of selected proteins that interact with the central pore-forming subunit of high-voltage-activated calcium channels.

  2. Effect of moxonidine on contractile activity of isolated large intestine in mice: role of alpha2-adrenoceptors and Ii-imidazoline receptors.

    Science.gov (United States)

    Kozaeva, L P; Korobov, N V; Medvedev, O S

    2004-03-01

    We studied the ability of moxonidine to interact with alpha2-adrenoceptors and Ii-imidazoline receptors in isolated mouse large intestine. Moxonidine caused contractions of longitudinal muscles in the large intestine, which depended on the dose of this preparation. Pretreatment with yohimbine (alpha2-adrenoceptor antagonist with low affinity for Ii-imidazoline receptors) and efaroxan (Ii-imidazoline receptor antagonist with low affinity for alpha2-adrenoceptors) abolished the effect of moxonidine. Antagonistic activity and relative selectivity of yohimbine and efaroxan suggest that the effects of moxonidine on mouse large intestine are realized via alpha2-adrenoceptors.

  3. Mono-nuclear copper complexes mimicking the intermediates for the binuclear copper center of the subunit II of cytochrome oxidase: a peptide based approach.

    Science.gov (United States)

    Dutta Gupta, Dwaipayan; Usharani, Dandamudi; Mazumdar, Shyamalava

    2016-11-28

    Three stable copper complexes of peptides derived from the copper ion binding loop of the subunit II of cytochrome c oxidase have been prepared and characterized by various spectroscopic techniques. These stable copper complexes of peptides were found to exhibit cysteine, histidine and/or methionine ligation, which has predominant σ-contribution in the Cys-Cu charge transfer. The copper(ii) peptide complexes showed type-2 EPR spectra, which is uncommon in copper-cysteinate complexes. UV-visible spectra, Raman and EPR results support a tetragonal structure of the coordination geometry around the copper ion. The copper complex of the 9-amino acid peptide suggested the formation of a 'red' copper center while the copper complexes of the 12- and 11-amino acid peptides showed the formation of a 'green' copper center. The results provide insights on the first stable models of the copper complexes formed in the peptide scaffold that mimic the mono-nuclear copper bound protein intermediates proposed during the formation of the binuclear Cu2S2 core of the enzyme. These three copper complexes of peptides derived from the metal ion binding loop of the CuA center of the subunit II of cytochrome c oxidase showed novel spectroscopic properties which have not so far been reported in any stable small complex.

  4. Na/H exchanger regulatory factors control parathyroid hormone receptor signaling by facilitating differential activation of G(alpha) protein subunits.

    Science.gov (United States)

    Wang, Bin; Ardura, Juan A; Romero, Guillermo; Yang, Yanmei; Hall, Randy A; Friedman, Peter A

    2010-08-27

    The Na/H exchanger regulatory factors, NHERF1 and NHERF2, are adapter proteins involved in targeting and assembly of protein complexes. The parathyroid hormone receptor (PTHR) interacts with both NHERF1 and NHERF2. The NHERF proteins toggle PTHR signaling from predominantly activation of adenylyl cyclase in the absence of NHERF to principally stimulation of phospholipase C when the NHERF proteins are expressed. We hypothesized that this signaling switch occurs at the level of the G protein. We measured G protein activation by [(35)S]GTPgammaS binding and G(alpha) subtype-specific immunoprecipitation using three different cellular models of PTHR signaling. These studies revealed that PTHR interactions with NHERF1 enhance receptor-mediated stimulation of G(alpha)(q) but have no effect on stimulation of G(alpha)(i) or G(alpha)(s). In contrast, PTHR associations with NHERF2 enhance receptor-mediated stimulation of both G(alpha)(q) and G(alpha)(i) but decrease stimulation of G(alpha)(s). Consistent with these functional data, NHERF2 formed cellular complexes with both G(alpha)(q) and G(alpha)(i), whereas NHERF1 was found to interact only with G(alpha)(q). These findings demonstrate that NHERF interactions regulate PTHR signaling at the level of G proteins and that NHERF1 and NHERF2 exhibit isotype-specific effects on G protein activation.

  5. Reduced volume but increased training intensity elevates muscle Na+-K+ pump alpha1-subunit and NHE1 expression as well as short-term work capacity in humans

    DEFF Research Database (Denmark)

    Iaia, F. Marcello; Thomassen, Martin; Kolding, Helle;

    2008-01-01

    by 30-s sprint runs three to four times a week, whereas CON continued the endurance training ( approximately 45 km/wk). After the 4-wk sprint period, the expression of the muscle Na(+)-K(+) pump alpha(1)-subunit and Na(+)/H(+)-exchanger isoform 1 was 29 and 30% higher (P ... pulmonary maximum oxygen uptake and 10-k time were unchanged. No changes in CON were observed. The present data suggest a role of the Na(+)-K(+) pump in the control of K(+) homeostasis and in the development of fatigue during repeated high-intensity exercise. Furthermore, performance during intense exercise...

  6. Paramyotonia congenita and hyperkalemic periodic paralysis associated with a Met 1592 Val substitution in the skeletal muscle sodium channel alpha subunit--a large kindred with a novel phenotype.

    Science.gov (United States)

    Kelly, P; Yang, W S; Costigan, D; Farrell, M A; Murphy, S; Hardiman, O

    1997-03-01

    Paramyotonia congenita (PC) and Hyperkalemic periodic paralysis (HyperPP) are caused by amino acid substitutions in the alpha subunit of the human skeletal muscle sodium channel. One such substitution, methionine for valine at position 1592, has been associated with HyperPP with myotonia and cold sensitivity. We report clinical, electromyographic (EMG), genetic and pathological features of a large kindred with the Met1592Val substitution. Affected members were phenotypically heterogenous and had episodic potassium-sensitive paralysis, and stiffness and weakness induced by exercise and cold, which was confirmed by EMG studies. These features indicate a combined PC-HyperPP phenotype not previously described with this mutation.

  7. Topoisomerase II alpha--a fundamental prognostic factor in breast carcinoma.

    Science.gov (United States)

    Hajduk, Magdalena

    2009-01-01

    Because of the introduction of modern diagnostic methods, numerous prognostic and predictive factors have been recognized and are today considered classic, yet they seem to be insufficient in assessment of prognosis, hence the need for further investigations. Among factors newly discovered by molecular techniques, there are class I and II topoisomerases, the role of which as prognosticators has not been fully determined. The objective of the present investigation was the assessment of topoisomerase II alpha (TOP2A) expression in patients with infiltrating breast carcinoma, as a prognostic factor in correlation with other recognized prognosticators and patient survival. The study was carried out in 151 patients treated by mastectomy and lymph node excision followed by adjuvant chemotherapy. The material was evaluated histopathologically according to the pTNM system, taking into consideration such parameters as grade of malignancy (G); the ER, PR as well as HER2 and TOP2A receptors status--all of them were assessed immunohistochemically. TOP2A was expressed with varying intensity in the majority of infiltrating ductal carcinomas studied, more frequently in large T3 and T4, grade G2 and G3 tumours, in patients with extensive metastases to regional N2 and N3 lymph nodes, a positive HER2 and negative ER and PR status. Five-year mortality rates were higher and 5-year symptom-free survival rates were lower in patients with TOP2A-positive tumours as compared to individuals with a negative TOP2A status. The study indicates that TOP2A expression is a negative predictive factor and may be recognized as a prognostic factor.

  8. Beta-to-alpha transformation in polycrystalline SiC. II - Interfacial energetics

    Science.gov (United States)

    Mitchell, T. E.; Ogbuji, L. U.; Heuer, A. H.

    1978-01-01

    A phenomenological analysis of the energetics of the beta-to-alpha transformation in polycrystalline SiC is presented. It is found that the extreme anisotropy of the interfacial energy between alpha- and beta-SiC can account for the rapid growth of composite grains into the beta matrix during conventional sintering or hot-pressing processes. The composite grains consist of alpha-SiC plates 'sandwiched' between well-oriented and recrystallized beta-SiC 'envelopes'. The interfaces involving the 111 plane type of beta and (0001) of alpha have much lower energies than random beta/alpha interfaces.

  9. DNA sequence polymorphisms within the bovine guanine nucleotide-binding protein Gs subunit alpha (Gsα-encoding (GNAS genomic imprinting domain are associated with performance traits

    Directory of Open Access Journals (Sweden)

    Mullen Michael P

    2011-01-01

    Full Text Available Abstract Background Genes which are epigenetically regulated via genomic imprinting can be potential targets for artificial selection during animal breeding. Indeed, imprinted loci have been shown to underlie some important quantitative traits in domestic mammals, most notably muscle mass and fat deposition. In this candidate gene study, we have identified novel associations between six validated single nucleotide polymorphisms (SNPs spanning a 97.6 kb region within the bovine guanine nucleotide-binding protein Gs subunit alpha gene (GNAS domain on bovine chromosome 13 and genetic merit for a range of performance traits in 848 progeny-tested Holstein-Friesian sires. The mammalian GNAS domain consists of a number of reciprocally-imprinted, alternatively-spliced genes which can play a major role in growth, development and disease in mice and humans. Based on the current annotation of the bovine GNAS domain, four of the SNPs analysed (rs43101491, rs43101493, rs43101485 and rs43101486 were located upstream of the GNAS gene, while one SNP (rs41694646 was located in the second intron of the GNAS gene. The final SNP (rs41694656 was located in the first exon of transcripts encoding the putative bovine neuroendocrine-specific protein NESP55, resulting in an aspartic acid-to-asparagine amino acid substitution at amino acid position 192. Results SNP genotype-phenotype association analyses indicate that the single intronic GNAS SNP (rs41694646 is associated (P ≤ 0.05 with a range of performance traits including milk yield, milk protein yield, the content of fat and protein in milk, culled cow carcass weight and progeny carcass conformation, measures of animal body size, direct calving difficulty (i.e. difficulty in calving due to the size of the calf and gestation length. Association (P ≤ 0.01 with direct calving difficulty (i.e. due to calf size and maternal calving difficulty (i.e. due to the maternal pelvic width size was also observed at the rs

  10. Identification of Interleukin-27 (IL-27)/IL-27 Receptor Subunit Alpha as a Critical Immune Axis for In Vivo HIV Control.

    Science.gov (United States)

    Ruiz-Riol, M; Berdnik, D; Llano, A; Mothe, B; Gálvez, C; Pérez-Álvarez, S; Oriol-Tordera, B; Olvera, A; Silva-Arrieta, S; Meulbroek, M; Pujol, F; Coll, J; Martinez-Picado, J; Ganoza, C; Sanchez, J; Gómez, G; Wyss-Coray, T; Brander, C

    2017-08-15

    blood is a key conduit for transporting such factors. Investigating the communication factors promoting effective immune responses and having potentially antiviral functions against HIV using a novel focused omics approach ("communicome") has the potential to significantly improve our knowledge of effective host immunity and accelerate the HIV cure agenda. Including 140 subjects with variable viral loads and measuring the plasma levels of >600 soluble proteins, our data highlight the importance of Th17 cells and Wnt/β-catenin signaling in HIV control and especially identify the IL-27/IL-27 receptor subunit alpha (IL-27RA) axis as a predictor of plasma viral load and proviral copy number in the peripheral blood. These data may provide important guidance to therapeutic approaches in the HIV cure agenda. Copyright © 2017 Ruiz-Riol et al.

  11. DNA sequence polymorphisms within the bovine guanine nucleotide-binding protein Gs subunit alpha (Gsα)-encoding (GNAS) genomic imprinting domain are associated with performance traits

    Science.gov (United States)

    2011-01-01

    Background Genes which are epigenetically regulated via genomic imprinting can be potential targets for artificial selection during animal breeding. Indeed, imprinted loci have been shown to underlie some important quantitative traits in domestic mammals, most notably muscle mass and fat deposition. In this candidate gene study, we have identified novel associations between six validated single nucleotide polymorphisms (SNPs) spanning a 97.6 kb region within the bovine guanine nucleotide-binding protein Gs subunit alpha gene (GNAS) domain on bovine chromosome 13 and genetic merit for a range of performance traits in 848 progeny-tested Holstein-Friesian sires. The mammalian GNAS domain consists of a number of reciprocally-imprinted, alternatively-spliced genes which can play a major role in growth, development and disease in mice and humans. Based on the current annotation of the bovine GNAS domain, four of the SNPs analysed (rs43101491, rs43101493, rs43101485 and rs43101486) were located upstream of the GNAS gene, while one SNP (rs41694646) was located in the second intron of the GNAS gene. The final SNP (rs41694656) was located in the first exon of transcripts encoding the putative bovine neuroendocrine-specific protein NESP55, resulting in an aspartic acid-to-asparagine amino acid substitution at amino acid position 192. Results SNP genotype-phenotype association analyses indicate that the single intronic GNAS SNP (rs41694646) is associated (P ≤ 0.05) with a range of performance traits including milk yield, milk protein yield, the content of fat and protein in milk, culled cow carcass weight and progeny carcass conformation, measures of animal body size, direct calving difficulty (i.e. difficulty in calving due to the size of the calf) and gestation length. Association (P ≤ 0.01) with direct calving difficulty (i.e. due to calf size) and maternal calving difficulty (i.e. due to the maternal pelvic width size) was also observed at the rs43101491 SNP. Following

  12. Localization of type II collagen, long form alpha 1(IX) collagen, and short form alpha 1(IX) collagen transcripts in the developing chick notochord and axial skeleton.

    Science.gov (United States)

    Swiderski, R E; Solursh, M

    1992-06-01

    In this study we compare, by in situ hybridization, the spatial and temporal expression patterns of transcripts of avian type II collagen and the long and short forms of the (alpha 1) chain of type IX collagen during the development of the notochord and axial skeleton. We observed type II collagen and short form type IX collagen transcripts in the developing (stage 25-28) nonchondrogenic notochord. Conversely, long form type IX transcripts were not detectable in the notochord or perinotochordal sheath. Interestingly, all three transcripts colocalized in the developing chondrogenic vertebrae of the axial skeleton as well as in the chondrocranium and Meckel's cartilage. The expression of the short form of type IX collagen in these regions was more restricted than that of the long form. This report provides additional support for a complex regulatory pathway of cartilage marker gene expression in chondrogenic vs. nonchondrogenic tissues during avian embryogenesis.

  13. The alpha(1G)-subunit of a voltage-dependent Ca(2+) channel is localized in rat distal nephron and collecting duct

    DEFF Research Database (Denmark)

    Andreasen, D; Jensen, B L; Hansen, P B

    2000-01-01

    +CCD), and inner medullary collecting duct (IMCD). alpha(1G) mRNA was expressed in the IMCD cell line mIMCD-3. Single- and double-labeling immunohistochemistry and confocal laser microscopy on semithin paraffin sections of rat kidneys by using an anti-alpha(1G) antibody demonstrated a distinct labeling...

  14. MID1 and MID2 homo- and heterodimerise to tether the rapamycin-sensitive PP2A regulatory subunit, Alpha 4, to microtubules: implications for the clinical variability of X-linked Opitz GBBB syndrome and other developmental disorders

    Directory of Open Access Journals (Sweden)

    Cox Timothy C

    2002-01-01

    Full Text Available Abstract Background Patients with Opitz GBBB syndrome present with a variable array of developmental defects including craniofacial, cardiac, and genital anomalies. Mutations in the X-linked MID1 gene, which encodes a microtubule-binding protein, have been found in ~50% of Opitz GBBB syndrome patients consistent with the genetically heterogeneous nature of the disorder. A protein highly related to MID1, called MID2, has also been described that similarly associates with microtubules. Results To identify protein partners of MID1 and MID2 we undertook two separate yeast two-hybrid screens. Using this system we identified Alpha 4, a regulatory subunit of PP2-type phosphatases and a key component of the rapamycin-sensitive signaling pathway, as a strong interactor of both proteins. Analysis of domain-specific deletions has shown that the B-boxes of both MID1 and MID2 mediate the interaction with Alpha 4, the first demonstration in an RBCC protein of a specific role for the B-box region. In addition, we show that the MID1/2 coiled-coil motifs mediate both homo- and hetero-dimerisation, and that dimerisation is a prerequisite for association of the MID-Alpha 4 complex with microtubules. Conclusions Our findings not only implicate Alpha 4 in the pathogenesis of Opitz GBBB syndrome but also support our earlier hypothesis that MID2 is a modifier of the X-linked phenotype. Of further note is the observation that Alpha 4 maps to Xq13 within the region showing linkage to FG (Opitz-Kaveggia syndrome. Overlap in the clinical features of FG and Opitz GBBB syndromes warrants investigation of Alpha 4 as a candidate for causing FG syndrome.

  15. Changes in Na+, K+-ATPase activity and alpha 3 subunit expression in CNS after administration of Na+, K+-ATPase inhibitors.

    Science.gov (United States)

    Bersier, María Geraldina; Peña, Clara; Arnaiz, Georgina Rodríguez de Lores

    2011-02-01

    The expression of Na(+), K(+)-ATPase α3 subunit and synaptosomal membrane Na(+), K(+)-ATPase activity were analyzed after administration of ouabain and endobain E, respectively commercial and endogenous Na(+), K(+)-ATPase inhibitors. Wistar rats received intracerebroventricularly ouabain or endobain E dissolved in saline solution or Tris-HCl, respectively or the vehicles (controls). Two days later, animals were decapitated, cerebral cortex and hippocampus removed and crude and synaptosomal membrane fractions were isolated. Western blot analysis showed that Na(+), K(+)-ATPase α3 subunit expression increased roughly 40% after administration of 10 or 100 nmoles ouabain in cerebral cortex but remained unaltered in hippocampus. After administration of 10 μl endobain E (1 μl = 28 mg tissue) Na(+), K(+)-ATPase α3 subunit enhanced 130% in cerebral cortex and 103% in hippocampus. The activity of Na(+), K(+)-ATPase in cortical synaptosomal membranes diminished or increased after administration of ouabain or endobain E, respectively. It is concluded that Na(+), K(+)-ATPase inhibitors modify differentially the expression of Na(+), K(+)-ATPase α3 subunit and enzyme activity, most likely involving compensatory mechanisms.

  16. The inhibition of P338 lymphocytic leukemia DNA polymerase alpha activity by cis-diamminedichloroplatinum(II) and related derivatives.

    Science.gov (United States)

    Oswald, C B; Hall, I H

    1989-01-01

    Cis-platinum derivatives were observed to inhibit the activity of DNA polymerase alpha of P388 lymphocytic leukemia cells. A 600g nuclear preparation of the polymerase alpha was inhibited by cis-diamminedichloroplatinum(II) [cDDP], diamminemalonatoplatinum(II) [MAL], (1,2-diaminocyclohexane)-dichloroplatinum(II) [DACH-Pt-CL2], and (1,2-diaminocyclohexane)malonato-platinum(II) [DACH-Pt-MAL]. cDDP was a more potent inhibitor of the enzyme activity which was positively correlated with the observed inhibition of DNA synthesis of P388 cells in vivo and in vitro. The inhibition of the 600g preparation by cDDP could be partially reversed by the addition of exogenous ctDNA, but 35% inhibition was not retreivable by adding new template. Isolation of the P388 DNA polymerase alpha enzyme by DEAE column chromatography led to an enzyme with 100 fold purification, which was sensitive to N-ethyl maleimide at 0.1 mM concentration. cDDP inhibited the activity of this enzyme in a dose dependent manner. However, MAL, DACH-Pt-Cl2 and DACH-Pt-MAL afforded no inhibition, nor did the latter two derivatives bind to the enzyme. cDDP inhibition of the activity of purified enzyme was partially reversed by the addition of exogenous ctDNA and by the addition of dGTP, whereas addition of other d(NTP)s had no effect on the recovery of the enzyme activity. These studies suggest that cDDP inhibits DNA polymerase alpha activity and that the inhibition is not the sole mechanism of the action of the drug in suppression of DNA synthesis and cell death. Preliminary studies suggest that the drug may bind to the apoprotein of the enzyme in a competitive manner with dGTP.

  17. Prevalence of estrogen receptor alpha PvuII and XbaI polymorphism in population of Polish postmenopausal women.

    Directory of Open Access Journals (Sweden)

    Jozef Haczynski

    2008-01-01

    Full Text Available Numerous data indicate that polymorphism of estrogen receptor alpha (ERalpha may predict lipid levels, lipid response to hormone replacement therapy (HRT, myocardial infarction risk, bone fracture risk, bone mineral density (BMD and changes in BMD over time. In this study we aimed to evaluate distribution of ERalpha PvuII and XbaI genotypes in population of Polish postmenopausal women qualified to different protocols of HRT. Subject of the study were 64 consecutive postmenopausal women aged from 45 to 65 years (mean 56.6 assigned to HRT. ERalpha PvuII and XbaI polymorphism was determined by PCR-restriction fragment length polymorphism (RFLP. The absence of PvuII and XbaI restriction sites were indicated by "P" and "X" and presence by "p" and "x", respectively. PvuII genotype was distributed as follows: PP 17.2% (n=11, Pp 50% (n=32, pp 32.83% (n=21. Frequency of XbaI genotype was: XX 6.25% (n=4, Xx 34.4% (n=22, xx 59.4% (n=38. Four haplotypes with following frequencies were recognized: PX 17.3%, px 47.4%, Px 24.4% and pX 10.9%. Prevalence of estrogen receptor alpha PvuII and XbaI polymorphisms in Polish women is similar to previously studied population.

  18. Linking supply to demand: the neuronal monocarboxylate transporter MCT2 and the alpha-amino-3-hydroxyl-5-methyl-4-isoxazole-propionic acid receptor GluR2/3 subunit are associated in a common trafficking process.

    Science.gov (United States)

    Pierre, Karin; Chatton, Jean-Yves; Parent, Annabelle; Repond, Cendrine; Gardoni, Fabrizio; Di Luca, Monica; Pellerin, Luc

    2009-05-01

    MCT2 is the major neuronal monocarboxylate transporter (MCT) that allows the supply of alternative energy substrates such as lactate to neurons. Recent evidence obtained by electron microscopy has demonstrated that MCT2, like alpha-amino-3-hydroxyl-5-methyl-4-isoxazole-propionic acid (AMPA) receptors, is localized in dendritic spines of glutamatergic synapses. Using immunofluorescence, we show in this study that MCT2 colocalizes extensively with GluR2/3 subunits of AMPA receptors in neurons from various mouse brain regions as well as in cultured neurons. It also colocalizes with GluR2/3-interacting proteins, such as C-kinase-interacting protein 1, glutamate receptor-interacting protein 1 and clathrin adaptor protein. Coimmunoprecipitation of MCT2 with GluR2/3 and C-kinase-interacting protein 1 suggests their close interaction within spines. Parallel changes in the localization of both MCT2 and GluR2/3 subunits at and beneath the plasma membrane upon various stimulation paradigms were unraveled using an original immunocytochemical and transfection approach combined with three-dimensional image reconstruction. Cell culture incubation with AMPA or insulin triggered a marked intracellular accumulation of both MCT2 and GluR2/3, whereas both tumor necrosis factor alpha and glycine (with glutamate) increased their cell surface immunolabeling. Similar results were obtained using Western blots performed on membrane or cytoplasm-enriched cell fractions. Finally, an enhanced lactate flux into neurons was demonstrated after MCT2 translocation on the cell surface. These observations provide unequivocal evidence that MCT2 is linked to AMPA receptor GluR2/3 subunits and undergoes a similar translocation process in neurons upon activation. MCT2 emerges as a novel component of the synaptic machinery putatively linking neuroenergetics to synaptic transmission.

  19. Structural analysis of Golgi alpha-mannosidase II inhibitors identified from a focused glycosidase inhibitor screen.

    Science.gov (United States)

    Kuntz, Douglas A; Tarling, Chris A; Withers, Stephen G; Rose, David R

    2008-09-23

    The N-glycosylation pathway is a target for pharmaceutical intervention in a number of pathological conditions including cancer. Golgi alpha-mannosidase II (GMII) is the final glycoside hydrolase in the pathway and has been the target for a number of synthetic efforts aimed at providing more selective and effective inhibitors. Drosophila GMII (dGMII) has been extensively studied due to the ease of obtaining high resolution structural data, allowing the observation of substrate distortion upon binding and after formation of a trapped covalent reaction intermediate. However, attempts to find new inhibitor leads by high-throughput screening of large commercial libraries or through in silico docking were unsuccessful. In this paper we provide a kinetic and structural analysis of five inhibitors derived from a small glycosidase-focused library. Surprisingly, four of these were known inhibitors of beta-glucosidases. X-ray crystallographic analysis of the dGMII:inhibitor complexes highlights the ability of the zinc-containing GMII active site to deform compounds, even ones designed as conformationally restricted transition-state mimics of beta-glucosidases, into binding entities that have inhibitory activity. Although these deformed conformations do not appear to be on the expected conformational itinerary of the enzyme, and are thus not transition-state mimics of GMII, they allow positioning of the three vicinal hydroxyls of the bound gluco-inhibitors into similar locations to those found with mannose-containing substrates, underlining the importance of these hydrogen bonds for binding. Further, these studies show the utility of targeting the acid-base catalyst using appropriately positioned positively charged nitrogen atoms, as well as the challenges associated with aglycon substitutions.

  20. Characterization and expression of MHC class II alpha and II beta genes in mangrove red snapper (Lutjanus argentimaculatus).

    Science.gov (United States)

    Wang, Tianyan; Tan, Shangjin; Cai, Zhonghua

    2015-12-01

    The major histocompatibility complex (MHC) class II plays a key role in adaptive immunity by presenting foreign peptides to CD4(+) T cells and by triggering the adaptive immune response. While the structure and function of MHC class II have been well characterized in mammalian, limited research has been done on fishes. In this study, we characterized the gene structure and expression of MHC class II α (Lunar-DAA) and II β (Lunar-DAB) of mangrove red snapper (Lutjanus argentimaculatus). Both genes shared, respectively, a high similarity and typical features with other vertebrate MHC class II α and II β. The phylogenetic analysis of the deduced peptides revealed that both Lunar-DAA and Lunar-DAB were located in the teleost subclass. Western blotting analyses indicated that both MHC class II α and II β were expressed ubiquitously in immune-related cells, tissues and organs, and that MHC class II α and II β chains existed mainly as heterodimers. While it was highly expressed in gills, thymus, head kidney (HK), spleen, head kidney macrophage and spleen leucocytes, MHC class II β chain was expressed with a low abundance in skin, intestine, stomach and heart. The highest expression of MHC class II β in thymus confirmed the conclusion that thymus is one of the primary lymphoid organs in fishes. The detection of MHC class II αβ dimers in HK macrophages and spleen leucocytes indicated that HK macrophages and spleen leucocytes play a critical role in the adaptive immunity in fishes. All these results provide valuable information for understanding the structure of MHC class II α and II β and their function in immune responses.

  1. Hepatoid carcinoma of the pancreas producing protein induced by vitamin K absence or antagonist II (PIVKA-II) and alpha-fetoprotein (AFP).

    Science.gov (United States)

    Matsueda, Kazuhiro; Yamamoto, Hiroshi; Yoshida, Yasuo; Notohara, Kenji

    2006-10-01

    We describe a rare case of hepatoid carcinoma of the pancreas with production of protein induced by vitamin K absence or antagonist II (PIVKA-II) and alpha-fetoprotein (AFP). The patient was a 49-year-old woman admitted because of high serum levels of PIVKA-II (1.63 AU/ml) and AFP (623 ng/ml) and abnormal ultrasonographic findings of the pancreas, found incidentally at medical checkup. Both ultrasonography and computed tomography showed swelling of the pancreas with small areas of low density, but no hepatic lesions. The serum levels of carcinoembryonic antigen and carbohydrate antigen 19-9 were not increased. A PIVKA-II and AFP-producing pancreatic cancer was strongly suspected, and total pancreatectomy was performed. Pathological examination showed that the tumor cells were arranged in trabecular and solid patterns with bile production, and were immunohistochemically positive for PIVKA-II and AFP, resembling hepatocellular carcinoma cells. The tumor was diagnosed as hepatoid carcinoma of the pancreas, and the patient has survived 48 months after initial diagnosis. It is important that hepatoid carcinoma be considered as a possible malignant tumor of the pancreas, and simultaneous measurement of the serum levels of AFP and PIVKA-II will enable earlier diagnosis. This is the first report describing hepatoid carcinoma of the pancreas producing PIVKA-II.

  2. On the Lack of Correlation Between Mg II 2796, 2803 Angstrom and Lyman alpha Emission in Lensed Star-Forming Galaxies

    Science.gov (United States)

    Rigby, Jane Rebecca; Bayliss, M. B.; Gladders, M. D.; Sharon, K.; Wuyts, E.; Dahle, H.

    2014-01-01

    We examine the Mg II 2796, 2803 Angstrom, Lyman alpha, and nebular line emission in five bright star-forming galaxies at 1.66 less than z less than 1.91 that have been gravitationally lensed by foreground galaxy clusters. All five galaxies show prominent Mg II emission and absorption in a P Cygni profile. We find no correlation between the equivalent widths of Mg II and Lyman alpha emission. The Mg II emission has a broader range of velocities than do the nebular emission line profiles; the Mg II emission is redshifted with respect to systemic by 100 to 200 km s(exp-1). When present, Lyman alpha is even more redshifted. The reddest components of Mg II and Lyman alpha emission have tails to 500-600 km s(exp-1), implying a strong outflow. The lack of correlation in the Mg II and Lyman alpha equivalent widths, the differing velocity profiles, and the high ratios of Mg II to nebular line fluxes together suggest that the bulk of Mg II emission does not ultimately arise as nebular line emission, but may instead be reprocessed stellar continuum emission.

  3. Pivotal Role for a Tail Subunit of the RNA Polymerase II Mediator Complex CgMed2 in Azole Tolerance and Adherence in Candida glabrata

    Science.gov (United States)

    Borah, Sapan; Shivarathri, Raju; Srivastava, Vivek Kumar; Ferrari, Sélène; Sanglard, Dominique

    2014-01-01

    Antifungal therapy failure can be associated with increased resistance to the employed antifungal agents. Candida glabrata, the second most common cause of invasive candidiasis, is intrinsically less susceptible to the azole class of antifungals and accounts for 15% of all Candida bloodstream infections. Here, we show that C. glabrata MED2 (CgMED2), which codes for a tail subunit of the RNA polymerase II Mediator complex, is required for resistance to azole antifungal drugs in C. glabrata. An inability to transcriptionally activate genes encoding a zinc finger transcriptional factor, CgPdr1, and multidrug efflux pump, CgCdr1, primarily contributes to the elevated susceptibility of the Cgmed2Δ mutant toward azole antifungals. We also report for the first time that the Cgmed2Δ mutant exhibits sensitivity to caspofungin, a constitutively activated protein kinase C-mediated cell wall integrity pathway, and elevated adherence to epithelial cells. The increased adherence of the Cgmed2Δ mutant was attributed to the elevated expression of the EPA1 and EPA7 genes. Further, our data demonstrate that CgMED2 is required for intracellular proliferation in human macrophages and modulates survival in a murine model of disseminated candidiasis. Lastly, we show an essential requirement for CgMed2, along with the Mediator middle subunit CgNut1 and the Mediator cyclin-dependent kinase/cyclin subunit CgSrb8, for the high-level fluconazole resistance conferred by the hyperactive allele of CgPdr1. Together, our findings underscore a pivotal role for CgMed2 in basal tolerance and acquired resistance to azole antifungals. PMID:25070095

  4. Two aspartate residues at the putative p10 subunit of a type II metacaspase from Nicotiana tabacum L. may contribute to the substrate-binding pocket.

    Science.gov (United States)

    Acosta-Maspons, Alexis; Sepúlveda-García, Edgar; Sánchez-Baldoquín, Laura; Marrero-Gutiérrez, Junier; Pons, Tirso; Rocha-Sosa, Mario; González, Lien

    2014-01-01

    Metacaspases are cysteine proteases present in plants, fungi, prokaryotes, and early branching eukaryotes, although a detailed description of their cellular function remains unclear. Currently, three-dimensional (3D) structures are only available for two metacaspases: Trypanosoma brucei (MCA2) and Saccharomyces cerevisiae (Yca1). Furthermore, metacaspases diverged from animal caspases of known structure, which limits straightforward homology-based interpretation of functional data. We report for the first time the identification and initial characterization of a metacaspase of Nicotiana tabacum L., NtMC1. By combining domain search, multiple sequence alignment (MSA), and protein fold-recognition studies, we provide compelling evidences that NtMC1 is a plant metacaspase type II, and predict its 3D structure using the crystal structure of two type I metacaspases (MCA2 and Yca1) and Gsu0716 protein from Geobacter sulfurreducens as template. Analysis of the predicted 3D structure allows us to propose Asp353, at the putative p10 subunit, as a new member of the aspartic acid triad that coordinates the P1 arginine/lysine residue of the substrate. Nevertheless, site-directed mutagenesis and expression analysis in bacteria and Nicotiana benthamiana indicate the functionality of both Asp348 and Asp353. Through the co-expression of mutant and wild-type proteins by transient expression in N. benthamiana leaves we found that polypeptide processing seems to be intramolecular. Our results provide the first evidence in plant metacaspases concerning the functionality of the putative p10 subunit.

  5. Mutations in mitochondrial-encoded cytochrome c oxidase subunits I, II, and III genes detected in Alzheimer's disease using single-strand conformation polymorphism.

    Science.gov (United States)

    Hamblet, Natasha S; Ragland, Brian; Ali, Mervat; Conyers, Barbara; Castora, Frank J

    2006-02-01

    A "mitochondrial hypothesis" of late onset Alzheimer's disease (AD) has been proposed. Biochemical studies indicate that there is a significant decrease in cytochrome oxidase (CO) activity as well as perturbed CO I and CO III mRNA levels in platelets and brain tissue from Alzheimer's patients. Using the electrophoretic mutation detection technique SSCP and DNA sequencing, we have identified 20 point mutations in the mitochondrial-encoded CO subunits (CO I, II, and III) in AD and age-matched control brain samples. Eight of the mutations are new variants of the mitochondrial genome. The efficiency of SSCP in detecting mutations in the CO subunits was estimated to be 80% when compared to dideoxy sequencing. One of the mutations (at position 9,861) results in a phenylalanine-->leucine substitution at a highly conserved residue in CO III. CO activity was reduced by an average of 35% in all AD brains compared to age-matched control samples, which agrees with previous reports. CO activity in one of the AD brain samples carrying the 9,861 mutation decreased by 80% relative to control brain samples, suggesting that the phenotypic expression of this mutation may result in reduced CO activity and compromised mitochondrial function.

  6. Linkage of the gene that encodes the alpha 1 chain of type V collagen (COL5A1) to type II Ehlers-Danlos syndrome (EDS II).

    Science.gov (United States)

    Loughlin, J; Irven, C; Hardwick, L J; Butcher, S; Walsh, S; Wordsworth, P; Sykes, B

    1995-09-01

    Ehlers-Danlos syndrome (EDS) is a group of heritable disorders of connective tissue with skin, ligaments and blood vessels being the main sites affected. The commonest variant (EDS II) exhibits an autosomal dominant mode of inheritance and is characterized by joint hypermobility, cigarette paper scars, lax skin and excessive bruising. As yet no gene has been linked to EDS II, nor has linkage been established to a specific region of the genome. However, several candidate genes encoding proteins of the extracellular matrix have been excluded. Using an intragenic simple sequence repeat polymorphism, we report linkage of the COL5A1 gene, which encodes the alpha 1(V) chain of type V collagen, to EDS II. A maximum LOD score (Zmax) for linkage of 8.3 at theta = 0.00 was generated for a single large pedigree.

  7. Fluxes in H\\alpha and Ca II H and K for a sample of Southern stars

    CERN Document Server

    Cincunegui, C; Mauas, P J D; Cincunegui, Carolina; D\\'iaz, Rodrigo F.; Mauas, Pablo J. D.

    2007-01-01

    The main chromospheric activity indicator is the S index, which is esentially the ratio of the flux in the core of the Ca II H and K lines to the continuum nearby, and is well studied basically for stars from F to K. Another usual chromospheric proxy is the H\\alpha line, which is beleived to be tightly correlated with the Ca II index. In this work we characterize both chromospheric activity indicators, one associated with the H and K Ca II lines and the other with H\\alpha, for the whole range of late type stars, from F to M. We present periodical medium-resolution echelle observations covering the complete visual range, which were taken at the CASLEO Argentinean Observatory. These observations are distributed along 7 years. We use a total of 917 flux-calibrated spectra for 109 stars which range from F6 to M5. We statistically study these two indicators for stars of different activity levels and spectral types. We directly derive the conversion factor which translate the known S index to flux in the Ca II core...

  8. On the selection of damped Lyman alpha systems using MgII absorption at 2

    CERN Document Server

    Berg, T A M; Prochaska, J X; Sanchez-Ramirez, R; Lopez, S; D'Odorico, V; Becker, G; Christensen, L; Cupani, G; Denney, K; Worseck, G

    2016-01-01

    The XQ-100 survey provides optical and near infrared coverage of 36 blindly selected, intervening damped Lyman alpha systems (DLAs) at 2 < z < 4, simultaneously covering the MgII doublet at 2796A, 2803A, and the Ly-alpha transition. Using the XQ-100 DLA sample, we investigate the completeness of selecting DLA absorbers based on their MgII rest-frame equivalent width (W2796) at these redshifts. Of the 29 DLAs with clean MgII profiles, we find that six (20% of DLAs) have W2796 < 0.6A. The DLA incidence rate of W2796 < 0.6A absorbers is a factor of ~5 higher than what is seen in z~1 samples, indicating a potential evolution in the MgII properties of DLAs with redshift. All of the W2796 < 0.6A DLAs have low metallicities (-2.5 < [M/H] < -1.7), small velocity widths (v90 < 50 km/s), and tend to have relatively low N(HI). We demonstrate that the exclusion of these low W2796 DLAs results in a higher mean N(HI) which in turn leads to a ~7% increase in the cosmological gas density of HI of DLAs...

  9. Arabidopsis thaliana RGXT1 and RGXT2 encode Golgi-localized (1,3)-alpha-D-xylosyltransferases involved in the synthesis of pectic rhamnogalacturonan-II

    DEFF Research Database (Denmark)

    Madsen, Jack Egelund; Petersen, Bent Larsen; Motawia, Mohammed Saddik

    2006-01-01

    of a type II membrane protein structure. Soluble secreted forms of the corresponding proteins expressed in insect cells showed xylosyltransferase activity, transferring d-xylose from UDP-alpha-d-xylose to l-fucose. The disaccharide product was hydrolyzed by alpha-xylosidase, whereas no reaction...

  10. Dopamine D3 receptor-dependent changes in alpha6 GABAA subunit expression in striatum modulate anxiety-like behaviour: Responsiveness and tolerance to diazepam.

    Science.gov (United States)

    Leggio, Gian Marco; Torrisi, Sebastiano Alfio; Castorina, Alessandro; Platania, Chiara Bianca Maria; Impellizzeri, Agata Antonia Rita; Fidilio, Annamaria; Caraci, Filippo; Bucolo, Claudio; Drago, Filippo; Salomone, Salvatore

    2015-09-01

    Increasing evidence indicates that central dopamine (DA) neurotransmission is involved in pathophysiology of anxiety, in particular the DA receptor subtype 3 (D3R). We previously reported that D3R null mice (D3R(-/-)) exhibit low baseline anxiety levels and that acutely administrated diazepam is more effective in D3R(-/-) than in wild type (WT) when tested in the elevated plus maze test (EPM). Here we tested the hypothesis that genetic deletion or pharmacological blockade of D3R affect GABAA subunit expression, which in turn modulates anxiety-like behaviour as well as responsiveness and tolerance to diazepam. D3R(-/-) mice exhibited tolerance to diazepam (0.5mg/kg, i.p.), assessed by EPM, as fast as after 3 day-treatment, performing similarly to untreated D3R(-/-) mice; conversely, WT exhibited tolerance to diazepam after a 14-21 day-treatment. Analysis of GABAA α6 subunit mRNA expression by qPCR in striatum showed that it was about 15-fold higher in D3R(-/-) than in WT. Diazepam treatment did not modify α6 expression in D3R(-/-), but progressively increased α6 expression in WT, to the level of untreated D3R(-/-) after 14-21 day-treatment. BDNF mRNA expression in striatum was remarkably (>10-fold) increased after 3 days of diazepam-treatment in both WT and D3R(-/-); such expression level, however, slowly declined below control levels, by 14-21 days. Following a 7 day-treatment with the selective D3R antagonist SB277011A, WT exhibited a fast tolerance to diazepam accompanied by a robust increase in α6 subunit expression. In conclusion, genetic deletion or pharmacological blockade of D3R accelerate the development of tolerance to repeated administrations of diazepam and increase α6 subunit expression, a GABAA subunit that has been linked to diazepam insensitivity. Modulation of GABAA receptor by DA transmission may be involved in the mechanisms of anxiety and, if occurring in humans, may have therapeutic relevance following repeated use of drugs targeting D3R.

  11. Comparative structure analyses of cystine knot-containing molecules with eight aminoacyl ring including glycoprotein hormones (GPH alpha and beta subunits and GPH-related A2 (GPA2 and B5 (GPB5 molecules

    Directory of Open Access Journals (Sweden)

    Combarnous Yves

    2009-08-01

    Full Text Available Abstract Background Cystine-knot (cys-knot structure is found in a rather large number of secreted proteins and glycoproteins belonging to the TGFbeta and glycoprotein hormone (GPH superfamilies, many of which are involved in endocrine control of reproduction. In these molecules, the cys-knot is formed by a disulfide (SS bridge penetrating a ring formed by 8, 9 or 10 amino-acid residues among which four are cysteine residues forming two SS bridges. The glycoprotein hormones Follicle-Stimulating Hormone (FSH, Luteinizing Hormone (LH, Thyroid-Stimulating Hormone (TSH and Chorionic Gonadotropin (CG are heterodimers consisting of non-covalently associated alpha and beta subunits that possess cys-knots with 8-amino-acyl (8aa rings. In order to get better insight in the structural evolution of glycoprotein hormones, we examined the number and organization of SS bridges in the sequences of human 8-aa-ring cys-knot proteins having 7 (gremlins, 9 (cerberus, DAN, 10 (GPA2, GPB5, GPHα and 12 (GPHβ cysteine residues in their sequence. Discussion The comparison indicated that the common GPH-alpha subunit exhibits a SS bridge organization ressembling that of DAN and GPA2 but possesses a unique bridge linking an additional cysteine inside the ring to the most N-terminal cysteine residue. The specific GPHbeta subunits also exhibit a SS bridge organization close to that of DAN but it has two additional C-terminal cysteine residues which are involved in the formation of the "seat belt" fastened by a SS "buckle" that ensures the stability of the heterodimeric structure of GPHs. GPA2 and GPB5 exhibit no cys residue potentially involved in interchain SS bridge and GPB5 does not possess a sequence homologous to that of the seatbelt in GPH β-subunits. GPA2 and GPB5 are thus not expected to form a stable heterodimer at low concentration in circulation. Summary The 8-aa cys-knot proteins GPA2 and GPB5 are expected to form a heterodimer only at concentrations above 0

  12. EASY-II: a system for modelling of n, d, p, {\\gamma} and {\\alpha} activation and transmutation processes

    CERN Document Server

    Sublet, Jean-Christophe; Morgan, Guy; Koning, Arjan; Rochman, Dimitri

    2013-01-01

    EASY-II is designed as a functional replacement for the previous European Activation System, EASY-2010. It has extended nuclear data and new software, FISPACT-II, written in object-style Fortran to provide new capabilities for predictions of activation, transmutation, depletion and burnup. The new FISPACT-II code has allowed us to implement many more features in terms of energy range, up to GeV; incident particles: alpha, gamma, proton, deuteron and neutron; and neutron physics: self-shielding effects, temperature dependence, pathways analysis, sensitivity and error estimation using covariance data. These capabilities cover most application needs: nuclear fission and fusion, accelerator physics, isotope production, waste management and many more. In parallel, the maturity of modern general-purpose libraries such as TENDL-2012 encompassing thousands of target nuclides, the evolution of the ENDF format and the capabilities of the latest generation of processing codes PREPRO-2012, NJOY2012 and CALENDF-2010 have ...

  13. Abundances of Baade's Window Giants from Keck/HIRES Spectra: II. The Alpha- and Light Odd Elements

    CERN Document Server

    Fulbright, J P; Rich, R M; Fulbright, Jon. P.; William, Andrew Mc

    2006-01-01

    We report detailed chemical abundance analysis of 27 RGB stars towards the Galactic bulge in Baade's Window for elements produced by massive stars: O, Na, Mg, Al, Si, Ca and Ti. All of these elements are overabundant in the bulge relative to the disk, especially Mg, indicating that the bulge is enhanced in Type~II supernova ejecta and most likely formed more rapidly than the disk. We attribute a rapid decline of [O/Fe] to metallicity-dependent yields of oxygen in massive stars, perhaps connected to the Wolf-Reyet phenomenon. he explosive nucleosynthesis alphas, Si, Ca and Ti, possess identical trends with [Fe/H], consistent with their putative common origin. We note that different behaviors of hydrostatic and explosive alpha elements can be seen in the stellar abundances of stars in Local Group dwarf galaxies. We also attribute the decline of Si,Ca and Ti relative to Mg, to metallicity- dependent yields for the explosive alpha elements from Type~II supernovae. The starkly smaller scatter of [/Fe] with [Fe/H] ...

  14. Photodamage induced by Zinc(II)-phthalocyanine to microtubules, actin, alpha-actinin and keratin of HeLa cells.

    Science.gov (United States)

    Juarranz, A; Espada, J; Stockert, J C; Villanueva, A; Polo, S; Domínguez, V; Cañete, M

    2001-03-01

    We have studied the photosensitizing effects of zinc(II)-phthalocyanine (ZnPc) on the cytoskeleton of HeLa cells using sublethal (10(-7) M, followed by 1 or 3 min of red light to induce 20%, LD20, or 60%, LD60, cell death, respectively) or lethal (5 x 10(-6) M and 15 min of irradiation, LD100) experimental conditions. The immunofluorescent analysis of the cytoskeleton showed a variable photodamage to microtubules (MT), actin microfilaments (AF) and intermediate filaments of keratin (KF), as well as on alpha-actinin, which was dependent on treatment conditions. Both sublethal treatments induced deep alterations on interphase and mitotic MT. The mitotic index increased with time with the maximum at 18 h (12%) or 24 h (14%) after LD20 or LD60, respectively. The alterations on AF and alpha-actinin were much more severe than those observed on KF at any evaluated time. With the exception of the KF, which remained partially organized, the MT and AF network was severely damaged by the lethal treatment. Western blot analysis for alpha-tubulin, G-actin and alpha-actinin from soluble and insoluble fractions confirmed the results observed by immunofluorescence, thus indicating that these cytoskeletal components are involved in cell damage and death by ZnPc photosensitization.

  15. Evolutionary stellar population synthesis with MILES - II. Scaled-solar and \\alpha-enhanced models

    CERN Document Server

    Vazdekis, A; Cassisi, S; Ricciardelli, E; Falcón-Barroso, J; Sánchez-Blázquez, P; La Barbera, F; Beasley, M A; Pietrinferni, A

    2015-01-01

    We present models that predict spectra of old- and intermediate-aged stellar populations at 2.51\\AA\\ (FWHM) with varying [\\alpha/Fe] abundance. The models are based on the MILES library and on corrections from theoretical stellar spectra. The models employ recent [Mg/Fe] determinations for the MILES stars and BaSTI scaled-solar and \\alpha-enhanced isochrones. We compute models for a suite of IMF shapes and slopes, covering a wide age/metallicity range. Using BaSTI, we also compute "base models" matching The Galactic abundance pattern. We confirm that the \\alpha-enhanced models show a flux excess with respect to the scaled-solar models blue-ward $\\sim$4500\\AA, which increases with age and metallicity. We also confirm that both [MgFe] and [MgFe]' indices are [\\alpha/Fe]-insensitive. We show that the sensitivity of the higher order Balmer lines to [\\alpha/Fe] resides in their pseudo-continua, with narrower index definitions yielding lower sensitivity. We confirm that the \\alpha-enhanced models yield bluer (redde...

  16. Des-gamma carboxy prothrombin (PIVKA-II) and alpha-fetoprotein producing gastric cancer with multiple liver metastases.

    Science.gov (United States)

    Takahashi, Yoshihisa; Inoue, Tohru

    2003-04-01

    We describe the case of an 87-year-old woman who presented to Tokyo Kousei Nenkin Hospital because of appetite loss and general fatigue. Multiple liver masses and Borrmann type 2 gastric tumor were detected. A clinical diagnosis of hepatocellular carcinoma and gastric cancer was made based on the patient's high levels of serum alpha-fetoprotein (AFP; 490 200 ng/mL) and protein induced by vitamin K absence or antagonist-II (PIVKA-II, 2284 mAU/mL). The patient's general condition worsened gradually and she died 42 days after admission. Autopsy revealed that the predominant histological structure of the gastric tumor was trabecular or sheet-like, although a tubular structure was also found. Venous invasion was prominent. Immunohistochemically, the tumor tissue was positive for AFP and a few tumor cells were positive for PIVKA-II. The histological appearance and immunohistochemical features of the hepatic tumors resembled that of the gastric tumor. This case was pathologically diagnosed as AFP- and PIVKA-II-producing gastric carcinoma with multiple liver metastases. When tumors are found in the stomach and liver and serum PIVKA-II level is abnormally high, the possibility of PIVKA-II-producing gastric cancer with liver metastasis should be considered, especially when hepatitis virus markers are negative and liver cirrhosis is not present.

  17. Structural characterization of copper(II) binding to alpha-synuclein: Insights into the bioinorganic chemistry of Parkinson's disease.

    Science.gov (United States)

    Rasia, Rodolfo M; Bertoncini, Carlos W; Marsh, Derek; Hoyer, Wolfgang; Cherny, Dmitry; Zweckstetter, Markus; Griesinger, Christian; Jovin, Thomas M; Fernández, Claudio O

    2005-03-22

    The aggregation of alpha-synuclein (AS) is characteristic of Parkinson's disease and other neurodegenerative synucleinopathies. We demonstrate here that Cu(II) ions are effective in accelerating AS aggregation at physiologically relevant concentrations without altering the resultant fibrillar structures. By using numerous spectroscopic techniques (absorption, CD, EPR, and NMR), we have located the primary binding for Cu(II) to a specific site in the N terminus, involving His-50 as the anchoring residue and other nitrogen/oxygen donor atoms in a square planar or distorted tetragonal geometry. The carboxylate-rich C terminus, originally thought to drive copper binding, is able to coordinate a second Cu(II) equivalent, albeit with a 300-fold reduced affinity. The NMR analysis of AS-Cu(II) complexes reveals the existence of conformational restrictions in the native state of the protein. The metallobiology of Cu(II) in Parkinson's disease is discussed by a comparative analysis with other Cu(II)-binding proteins involved in neurodegenerative disorders.

  18. In cellulo examination of a beta-alpha hybrid construct of beta-hexosaminidase A subunits, reported to interact with the GM2 activator protein and hydrolyze GM2 ganglioside.

    Directory of Open Access Journals (Sweden)

    Incilay Sinici

    Full Text Available The hydrolysis in lysosomes of GM2 ganglioside to GM3 ganglioside requires the correct synthesis, intracellular assembly and transport of three separate gene products; i.e., the alpha and beta subunits of heterodimeric beta-hexosaminidase A, E.C. # 3.2.1.52 (encoded by the HEXA and HEXB genes, respectively, and the GM2-activator protein (GM2AP, encoded by the GM2A gene. Mutations in any one of these genes can result in one of three neurodegenerative diseases collectively known as GM2 gangliosidosis (HEXA, Tay-Sachs disease, MIM # 272800; HEXB, Sandhoff disease, MIM # 268800; and GM2A, AB-variant form, MIM # 272750. Elements of both of the hexosaminidase A subunits are needed to productively interact with the GM2 ganglioside-GM2AP complex in the lysosome. Some of these elements have been predicted from the crystal structures of hexosaminidase and the activator. Recently a hybrid of the two subunits has been constructed and reported to be capable of forming homodimers that can perform this reaction in vivo, which could greatly simplify vector-mediated gene transfer approaches for Tay-Sachs or Sandhoff diseases. A cDNA encoding a hybrid hexosaminidase subunit capable of dimerizing and hydrolyzing GM2 ganglioside could be incorporated into a single vector, whereas packaging both subunits of hexosaminidase A into vectors, such as adeno-associated virus, would be impractical due to size constraints. In this report we examine the previously published hybrid construct (H1 and a new more extensive hybrid (H2, with our documented in cellulo (live cell- based assay utilizing a fluorescent GM2 ganglioside derivative. Unfortunately when Tay-Sachs cells were transfected with either the H1 or H2 hybrid construct and then were fed the GM2 derivative, no significant increase in its turnover was detected. In vitro assays with the isolated H1 or H2 homodimers confirmed that neither was capable of human GM2AP-dependent hydrolysis of GM2 ganglioside.

  19. Copernicus observations of Ly-alpha and Mg II emission from HR 1099 /V711 Tauri/ and UX Ari

    Science.gov (United States)

    Weiler, E. J.

    1978-01-01

    Ultraviolet observations of two RS CVn binaries obtained with Copernicus are described. High-resolution (0.05 A) U1 observations indicate that both HR 1099 and UX Ari display broad Ly-alpha emission. The Ly-alpha emission strength from HR 1099 is variable and seems to be correlated with orbital phase, while the UX Ari results indicate no significant variation. Moderate resolution (0.51 A) V2 scans of both systems show variable Mg II h and k emission-line profiles which usually matched the velocity of the more active star in each binary. Additionally, displaced emission components were seen at velocities of up to + or - 250 km/s, indicative of high-velocity gas motions. The radial velocities of these emission features from HR 1099 are marginally correlated with orbital phase. Highly active and variable chromospheric phenomena are found to be the most consistent explanation of these results.

  20. Copernicus observations of Ly-alpha and Mg II emission from HR 1099 /V711 Tauri/ and UX Ari

    Science.gov (United States)

    Weiler, E. J.

    1978-01-01

    Ultraviolet observations of two RS CVn binaries obtained with Copernicus are described. High-resolution (0.05 A) U1 observations indicate that both HR 1099 and UX Ari display broad Ly-alpha emission. The Ly-alpha emission strength from HR 1099 is variable and seems to be correlated with orbital phase, while the UX Ari results indicate no significant variation. Moderate resolution (0.51 A) V2 scans of both systems show variable Mg II h and k emission-line profiles which usually matched the velocity of the more active star in each binary. Additionally, displaced emission components were seen at velocities of up to + or - 250 km/s, indicative of high-velocity gas motions. The radial velocities of these emission features from HR 1099 are marginally correlated with orbital phase. Highly active and variable chromospheric phenomena are found to be the most consistent explanation of these results.

  1. Glutamate-119 of the large alpha-subunit is the catalytic base in the hydration of 2-trans-enoyl-coenzyme A catalyzed by the multienzyme complex of fatty acid oxidation from Escherichia coli.

    Science.gov (United States)

    He, X Y; Yang, S Y

    1997-09-09

    Glu139 of the large alpha-subunit of the multienzyme complex of fatty acid oxidation from Escherichia coli was identified as the catalytic residue of enoyl-CoA hydratase [Yang, S.-Y., He, X.-Y., & Schulz, H. (1995) Biochemistry 34, 6441-6447]. To determine whether any of the other conserved protic residues is directly involved in the hydratase catalysis, the multienzyme complexes with either an alpha/Asp69 --> Asn or an alpha/Glu119 --> Gln mutation were overproduced and characterized. The catalytic properties of 3-ketoacyl-CoA thiolase and l-3-hydroxyacyl-CoA dehydrogenase of the mutant complexes were almost unaffected. The amidation of Asp69 and Glu119 caused a 7.6- and 88-fold decrease, respectively, in the kcat of enoyl-CoA hydratase without a significant change in the Km value of the hydratase as well as a 5.9- and 62-fold increase, respectively, in the Km of Delta3-cis-Delta2-trans-enoyl-CoA isomerase with a very small decrease in the kcat of the latter enzyme. The data suggest that the carboxyl group of Glu119 is particularly important to the catalytic activity of enoyl-CoA hydratase. Furthermore, the wild-type hydratase shows a bell-shaped pH dependence of the kcat/Km with pKa values of 5.9 and 9.2, whereas the Glu119 --> Gln mutant hydratase has only a single pKa of 9.5. A simple explanation for these observations is that a deprotonated Glu119 and a protonated Glu139 are required for the high kcat of the enoyl-CoA hydratase. The results of site-directed mutagenesis studies, together with the structural information about the spatial arrangement of two conserved glutamate residues of rat liver enoyl-CoA hydratase [Engel, C. K., Mathieu, M., Zeelen, J. P., Hiltunen, J. K., and Wierenga, R. K. (1996) EMBO J. 15, 5135-5145] to which Glu119 and Glu139 of the large alpha-subunit correspond, lead to the conclusion that the gamma-carboxyl group of Glu119 serves as the second general acid-base functional group in catalyzing the hydration of 2-trans-enoyl-CoA.

  2. A highly conserved glycine within linker I and the extreme C terminus of G protein alpha subunits interact cooperatively in switching G protein-coupled receptor-to-effector specificity

    DEFF Research Database (Denmark)

    Kostenis, Evi; Martini, Lene; Ellis, James;

    2004-01-01

    Numerous studies have attested to the importance of the extreme C terminus of G protein alpha subunits in determining their selectivity of receptor recognition. We have previously reported that a highly conserved glycine residue within linker I is important for constraining the fidelity of receptor...... recognition by Galpha(q) proteins. Herein, we explored whether both modules (linker I and extreme C terminus) interact cooperatively in switching G protein-coupled receptor (GPCR)-to-effector specificity and created as models mutant Galpha(q) proteins in which glycine was replaced with various amino acids...... and the C-terminal five Galpha(q) residues with the corresponding Galpha(i) or Galpha(s) sequence. Coupling properties of the mutated Galpha(q) proteins were determined after coexpression with a panel of 13 G(i)-and G(s) -selective receptors and compared with those of Galpha proteins modified in only one...

  3. Neutralization of Gating Charges in Domain II of the Sodium Channel α Subunit Enhances Voltage-Sensor Trapping by a β-Scorpion Toxin

    Science.gov (United States)

    Cestèle, Sandrine; Scheuer, Todd; Mantegazza, Massimo; Rochat, Hervé; Catterall, William A.

    2001-01-01

    β-Scorpion toxins shift the voltage dependence of activation of sodium channels to more negative membrane potentials, but only after a strong depolarizing prepulse to fully activate the channels. Their receptor site includes the S3–S4 loop at the extracellular end of the S4 voltage sensor in domain II of the α subunit. Here, we probe the role of gating charges in the IIS4 segment in β-scorpion toxin action by mutagenesis and functional analysis of the resulting mutant sodium channels. Neutralization of the positively charged amino acid residues in the IIS4 segment by mutation to glutamine shifts the voltage dependence of channel activation to more positive membrane potentials and reduces the steepness of voltage-dependent gating, which is consistent with the presumed role of these residues as gating charges. Surprisingly, neutralization of the gating charges at the outer end of the IIS4 segment by the mutations R850Q, R850C, R853Q, and R853C markedly enhances β-scorpion toxin action, whereas mutations R856Q, K859Q, and K862Q have no effect. In contrast to wild-type, the β-scorpion toxin Css IV causes a negative shift of the voltage dependence of activation of mutants R853Q and R853C without a depolarizing prepulse at holding potentials from −80 to −140 mV. Reaction of mutant R853C with 2-aminoethyl methanethiosulfonate causes a positive shift of the voltage dependence of activation and restores the requirement for a depolarizing prepulse for Css IV action. Enhancement of sodium channel activation by Css IV causes large tail currents upon repolarization, indicating slowed deactivation of the IIS4 voltage sensor by the bound toxin. Our results are consistent with a voltage-sensor–trapping model in which the β-scorpion toxin traps the IIS4 voltage sensor in its activated position as it moves outward in response to depolarization and holds it there, slowing its inward movement on deactivation and enhancing subsequent channel activation. Evidently

  4. The properties of the single chicken MHC classical class II alpha chain ( B-LA) gene indicate an ancient origin for the DR/E-like isotype of class II molecules

    DEFF Research Database (Denmark)

    Salomonsen, Jan; Marston, Denise; Avila, David;

    2003-01-01

    for the cloning and sequencing of the cDNA. We found only one class II alpha chain transcript, which bears the major features of a classical class II alpha sequence, including the critical peptide-binding residues. The chicken sequence is more similar to human DR than to the DQ, DP, DO or DM isotypes, most......In mammals, there are MHC class II molecules with distinctive sequence features, such as the classical isotypes DR, DQ and DP. These particular isotypes have not been reported in non-mammalian vertebrates. We have isolated the class II (B-L) alpha chain from outbred chickens as the basis...... significantly in the peptide-binding alpha(1) domain. The cDNA and genomic DNA sequences from chickens of diverse origins show few alleles, which differ in only four nucleotides and one amino acid. In contrast, significant restriction fragment length polymorphism is detected by Southern blot analysis of genomic...

  5. Haemoglobins of the shark, Heterodontus portusjacksoni II. Amino acid sequence of the alpha-chain.

    Science.gov (United States)

    Nash, A R; Fisher, W K; Thompson, E O

    1976-03-01

    The amino acid sequence of the alpha-chain of the principal haemoglobin from the shark, H. portusjacksoni has been determined. The chain has 148 residues and is acetylated at the amino terminal. The soluble peptides obtained by tryptic and chymotryptic digestion of the protein or its cyanogen bromide fragments were isolated by gel filtration, paper ionophoresis and paper chromatography. The amino acid sequences were determined by the dansyl-Edman procedure. The insoluble "core" peptide from the tryptic digestion contained 34 residues and required cleavage by several prosteases before the sequence was established. Compared with human alpha-chain there are 88 amino acid differences including the additional seven residues which appear on the amino terminal of the shark chain. There is also one deletion and one insertion. The chain contains no tryptophan but has four cysteinyl residues which is the highest number of such residues recorded for a vertebrate globin. In the alpha1beta1 contact sites there are four changes in the oxyhaemoglobin form and six deoxy form. Nine of the 16, alpha1beta1 contact sites show variation while three of the haem contact sites have changed in comparison to the residues known to be involved in these interactions in horse haemoglobin alpha-chain. Use of the sequence data to estimate a time of divergence of the shark from the main vertebrate line yielded the value of 410 +/- 46 million years. The data, in general, support the palaeontological view that bony fishes arose before the elasmobranchs.

  6. GABAA receptor subunit gene expression in human prefrontal cortex: comparison of schizophrenics and controls

    Science.gov (United States)

    Akbarian, S.; Huntsman, M. M.; Kim, J. J.; Tafazzoli, A.; Potkin, S. G.; Bunney, W. E. Jr; Jones, E. G.; Bloom, F. E. (Principal Investigator)

    1995-01-01

    The prefrontal cortex of schizophrenics is hypoactive and displays changes related to inhibitory, GABAergic neurons, and GABAergic synapses. These changes include decreased levels of glutamic acid decarboxylase (GAD), the enzyme for GABA synthesis, upregulation of muscimol binding, and downregulation of benzodiazepine binding to GABAA receptors. Studies in the visual cortex of nonhuman primates have demonstrated that gene expression for GAD and for several GABAA receptor subunit polypeptides is under control of neuronal activity, raising the possibility that similar mechanisms in the hypoactive prefrontal cortex of schizophrenics may explain the abnormalities in GAD and in GABAA receptor regulation. In the present study, which is the first of its type on human cerebral cortex, levels of mRNAs for six GABAA receptor subunits (alpha 1, alpha 2, alpha 5, beta 1, beta 2, gamma 2) and their laminar expression patterns were analyzed in the prefrontal cortex of schizophrenics and matched controls, using in situ hybridization histochemistry and densitometry. Three types of laminar expression pattern were observed: mRNAs for the alpha 1, beta 2, and gamma 2 subunits, which are the predominant receptor subunits expressed in the mature cortex, were expressed at comparatively high levels by cells of all six cortical layers, but most intensely by cells in lower layer III and layer IV. mRNAs for the alpha 2, alpha 5, and beta 1 subunits were expressed at lower levels; alpha 2 and beta 1 were expressed predominantly by cells in layers II, III, and IV; alpha 5 was expressed predominantly in layers IV, V, and VI. There were no significant changes in overall mRNA levels for any of the receptor subunits in the prefrontal cortex of schizophrenics, and the laminar expression pattern of all six receptor subunit mRNAs did not differ between schizophrenics and controls. Because gene expression for GABAA receptor subunits is not consistently altered in the prefrontal cortex of

  7. Structure of Ctk3, a subunit of the RNA polymerase II CTD kinase complex, reveals a noncanonical CTD-interacting domain fold.

    Science.gov (United States)

    Mühlbacher, Wolfgang; Mayer, Andreas; Sun, Mai; Remmert, Michael; Cheung, Alan C M; Niesser, Jürgen; Soeding, Johannes; Cramer, Patrick

    2015-10-01

    CTDK-I is a yeast kinase complex that phosphorylates the C-terminal repeat domain (CTD) of RNA polymerase II (Pol II) to promote transcription elongation. CTDK-I contains the cyclin-dependent kinase Ctk1 (homologous to human CDK9/CDK12), the cyclin Ctk2 (human cyclin K), and the yeast-specific subunit Ctk3, which is required for CTDK-I stability and activity. Here we predict that Ctk3 consists of a N-terminal CTD-interacting domain (CID) and a C-terminal three-helix bundle domain. We determine the X-ray crystal structure of the N-terminal domain of the Ctk3 homologue Lsg1 from the fission yeast Schizosaccharomyces pombe at 2.0 Å resolution. The structure reveals eight helices arranged into a right-handed superhelical fold that resembles the CID domain present in transcription termination factors Pcf11, Nrd1, and Rtt103. Ctk3 however shows different surface properties and no binding to CTD peptides. Together with the known structure of Ctk1 and Ctk2 homologues, our results lead to a molecular framework for analyzing the structure and function of the CTDK-I complex.

  8. Signal peptide homology between the sweet protein thaumatin II and unrelated cereal alpha-amylase/trypsin inhibitors.

    Science.gov (United States)

    Lázaro, A; Rodriguez-Palenzuela, P; Maraña, C; Carbonero, P; Garcia-Olmedo, F

    1988-10-24

    A cDNA clone (pUP-23) corresponding to a member of a protein family that includes inhibitors of trypsin and of heterologous alpha-amylases has been selected from a library derived from developing barley endosperm and its sequence has been determined. A stretch of 95 nucleotides that included the signal peptide and the first 8 residues of the mature protein was found to be homologous to an exactly equivalent region of the nucleotide sequence encoding the sweet protein thaumatin II. Evolutionary implications of this finding are discussed.

  9. A doppel alpha-helix peptide fragment mimics the copper(II) interactions with the whole protein.

    Science.gov (United States)

    La Mendola, Diego; Magrì, Antonio; Campagna, Tiziana; Campitiello, Maria Anna; Raiola, Luca; Isernia, Carla; Hansson, Orjan; Bonomo, Raffaele P; Rizzarelli, Enrico

    2010-06-01

    The doppel protein (Dpl) is the first homologue of the prion protein (PrP(C)) to be discovered; it is overexpressed in transgenic mice that lack the prion gene, resulting in neurotoxicity. The whole prion protein is able to inhibit Dpl neurotoxicity, and its N-terminal domain is the determinant part of the protein function. This region represents the main copper(II) binding site of PrP(C). Dpl is able to bind at least one copper ion, and the specific metal-binding site has been identified as the histidine residue at the beginning of the third helical region. However, a reliable characterization of copper(II) coordination features has not been reported. In a previous paper, we studied the copper(II) interaction with a peptide that encompasses only the loop region potentially involved in metal binding. Nevertheless, we did not find a complete match between the EPR spectroscopic parameters of the copper(II) complexes formed with the synthesized peptide and those reported for the copper(II) binding sites of the whole protein. Herein, the synthesis of the human Dpl peptide fragment hDpl(122-139) (Ac-KPDNKLHQQVLWRLVQEL-NH(2)) and its copper(II) complex species are reported. This peptide encompasses the third alpha helix and part of the loop linking the second and the third helix of human doppel protein. The single-point-mutated peptide, hDpl(122-139)D124N, in which aspartate 124 replaces an asparagine residue, was also synthesized. This peptide was used to highlight the role of the carboxylate group on both the conformation preference of the Dpl fragment and its copper(II) coordination features. NMR spectroscopic measurements show that the hDpl(122-139) peptide fragment is in the prevailing alpha-helix conformation. It is localized within the 127-137 amino acid residue region that represents a reliable conformational mimic of the related protein domain. A comparison with the single-point-mutated hDpl(122-139)D124N reveals the significant role played by the aspartic

  10. An intrinsically disordered photosystem II subunit, PsbO, provides a structural template and a sensor of the hydrogen-bonding network in photosynthetic water oxidation.

    Science.gov (United States)

    Offenbacher, Adam R; Polander, Brandon C; Barry, Bridgette A

    2013-10-04

    Photosystem II (PSII) is a membrane-bound enzyme that utilizes solar energy to catalyze the photooxidation of water. Molecular oxygen is evolved after four sequential light-driven oxidation reactions at the Mn4CaO5 oxygen-evolving complex, producing five sequentially oxidized states, Sn. PSII is composed of 17 membrane-spanning subunits and three extrinsic subunits, PsbP, PsbQ, and PsbO. PsbO is intrinsically disordered and plays a role in facilitation of the water oxidizing cycle. Native PsbO can be removed and substituted with recombinant PsbO, thereby restoring steady-state activity. In this report, we used reaction-induced Fourier transform infrared spectroscopy to obtain information concerning the role of PsbP, PsbQ, and PsbO during the S state cycle. Light-minus-dark difference spectra were acquired, monitoring structural changes associated with each accessible flash-induced S state transition in a highly purified plant PSII preparation (Triton X-100, octylthioglucoside). A comparison of S2 minus S1 spectra revealed that removal of PsbP and PsbQ had no significant effect on the data, whereas amide frequency and intensity changes were associated with PsbO removal. These data suggest that PsbO acts as an organizational template for the PSII reaction center. To identify any coupled conformational changes arising directly from PsbO, global (13)C-PsbO isotope editing was employed. The reaction-induced Fourier transform infrared spectra of accessible S states provide evidence that PsbO spectral contributions are temperature (263 and 277 K) and S state dependent. These experiments show that PsbO undergoes catalytically relevant structural dynamics, which are coupled over long distance to hydrogen-bonding changes at the Mn4CaO5 cluster.

  11. [A novel gene (Aa-accA ) encoding acetyl-CoA carboxyltransferase alpha-subunit of Alkalimonas amylolytica N10 enhances salt and alkali tolerance of Escherichia coli and tobacco BY-2 cells].

    Science.gov (United States)

    Xian, Mingjie; Zhai, Lei; Zhong, Naiqin; Ma, Yiwei; Xue, Yanfen; Ma, Yanhe

    2013-08-04

    Acetyl-CoA carboxylase (ACC) catalyzes the first step of fatty acid synthesis. In most bacteria, ACC is composed of four subunits encoded by accA, accB, accC, and accD. Of them, accA encodes acetyl-CoA carboxyltransferase alpha-subunit. Our prior work on proteomics of Alkalimonas amylolytica N10 showed that the expression of the Aa-accA has a remarkable response to salt and alkali stress. This research aimed to find out the Aa-accA gene contributing to salt and alkali tolerance. The Aa-accA was amplified by PCR from A. amylolytica N10 and expressed in E. coli K12 host. The effects of Aa-accA expression on the growth of transgenic strains were examined under different NaCl concentration and pH conditions. Transgenic tobacco BY-2 cells harboring Aa-accA were also generated via Agrobacterium-mediated transformation. The viability of BY-2 cells was determined with FDA staining method after salt and alkali shock. The Aa-accA gene product has 318 amino acids and is homologous to the carboxyl transferase domain of acyl-CoA carboxylases. It showed 76% identity with AccA (acetyl-CoA carboxylase carboxyltransferase subunit alpha) from E. coli. Compared to the wild-type strains, transgenic E. coli K12 strain containing Aa-accA showed remarkable growth superiority when grown in increased NaCl concentrations and pH levels. The final cell density of the transgenic strains was 2.6 and 3.5 times higher than that of the control type when they were cultivated in LB medium containing 6% (W/V) NaCl and at pH 9, respectively. Complementary expression of Aa-accA in an accA-depletion E. coli can recover the tolerance of K12 delta accA to salt and alkali stresses to some extent. Similar to the transgenic E. coli, transgenic tobacco BY-2 cells showed higher percentages of viability compared to the wild BY-2 cells under the salt or alkali stress condition. We found that Aa-accA from A. amylolytica N10 overexpression enhances the tolerance of both transgenic E. coli and tobacco BY-2 cells to

  12. NAC (Nascent Polypeptide-associated Complex) and Its Alpha Subunit NACA%NAC(初期多肽相关复合体)及其α亚基NACA

    Institute of Scientific and Technical Information of China (English)

    刘娇玲; 吕晓莉; 陈克平

    2015-01-01

    初期多肽相关复合体(nascent polypeptide-associated complex,NAC)是新生肽链从核糖体上延伸出来第一个接触的异二聚体蛋白复合体,从古生菌、酵母到哺乳动物都高度保守.NAC是一个具有多种功能的蛋白,包括保护新生肽链、调控新生肽转位进入内质网和线粒体、肌肉损伤修复等.其α亚基NACA/αNAC(nascent polypeptide-associated complex alpha subunit)主要在转录调控中起作用.此外,NACA还能调控FADD(Fas-associated with death domain protein)所介导的信号转导.在一些病毒性疾病,如乙肝、丙肝和非洲猪瘟中,NACA能与病毒的某些蛋白相互作用,致使机体功能紊乱.在老年痴呆症和唐氏综合征患者脑细胞中,与正常水平相比,NACA表达下调.%NAC (nascent polypeptide-associated complex) is the first cytosolic heterodimeric protein complex to contact nascent polypeptide chains emerging from ribosomes and is evolutionarily conserved in the genomes from archaea,yeast to mammals.NAC is found to be a multifunctional protein which can shield nascent chains,regulate nascent chains translocating into endoplasmic reticulum and mitochondria,repair muscle damage and so on.However,its α subunit NACA/αNAC (nascent polypeptide-associated complex alpha subunit) is identified mainly functioning in transcriptional regulation.It may play a role in FADD-mediated signal transduction process.Moreover,in many viral diseases,such as the Viral Hepatitis Type B,C and the African swine fever,it is found to be able to interact with the relevant viral protein to cause physiological disorders.Even in the brain tissues of patients with Alzheimer's disease and Down syndrome,NACA is found downregulated.

  13. Structural Characterization of the Loop at the Alpha-Subunit C-Terminus of the Mixed Lineage Leukemia Protein Activating Protease Taspase1.

    Directory of Open Access Journals (Sweden)

    Johannes van den Boom

    Full Text Available Type 2 asparaginases, a subfamily of N-terminal nucleophile (Ntn hydrolases, are activated by limited proteolysis. This activation yields a heterodimer and a loop region at the C-terminus of the α-subunit is released. Since this region is unresolved in all type 2 asparaginase crystal structures but is close to the active site residues, we explored this loop region in six members of the type 2 asparaginase family using homology modeling. As the loop model for the childhood cancer-relevant protease Taspase1 differed from the other members, Taspase1 activation as well as the conformation and dynamics of the 56 amino acids loop were investigated by CD and NMR spectroscopy. We propose a helix-turn-helix motif, which can be exploited as novel anticancer target to inhibit Taspase1 proteolytic activity.

  14. Estrogen receptor-alpha mediates estrogen protection from angiotensin II-induced hypertension in conscious female mice.

    Science.gov (United States)

    Xue, Baojian; Pamidimukkala, Jaya; Lubahn, Dennis B; Hay, Meredith

    2007-04-01

    It has been shown that the female sex hormones have a protective role in the development of angiotensin II (ANG II)-induced hypertension. The present study tested the hypotheses that 1) the estrogen receptor-alpha (ERalpha) is involved in the protective effects of estrogen against ANG II-induced hypertension and 2) central ERs are involved. Blood pressure (BP) was measured in female mice with the use of telemetry implants. ANG II (800 ng.kg(-1).min(-1)) was administered subcutaneously via an osmotic pump. Baseline BP in the intact, ovariectomized (OVX) wild-type (WT) and ERalpha knockout (ERalphaKO) mice was similar; however, the increase in BP induced by ANG II was greater in OVX WT (23.0 +/- 1.0 mmHg) and ERalphaKO mice (23.8 +/- 2.5 mmHg) than in intact WT mice (10.1 +/- 4.5 mmHg). In OVX WT mice, central infusion of 17beta-estradiol (E(2); 30 microg.kg(-1).day(-1)) attenuated the pressor effect of ANG II (7.0 +/- 0.4 mmHg), and this protective effect of E(2) was prevented by coadministration of ICI-182,780 (ICI; 1.5 microg.kg(-1).day(-1), 18.8 +/- 1.5 mmHg), a nonselective ER antagonist. Furthermore, central, but not peripheral, infusions of ICI augmented the pressor effects of ANG II in intact WT mice (17.8 +/- 4.2 mmHg). In contrast, the pressor effect of ANG II was unchanged in either central E(2)-treated OVX ERalphaKO mice (19.0 +/- 1.1 mmHg) or central ICI-treated intact ERalphaKO mice (19.6 +/- 1.6 mmHg). Lastly, ganglionic blockade on day 7 after ANG II infusions resulted in a greater reduction in BP in OVX WT, central ER antagonist-treated intact WT, central E(2) + ICI-treated OVX WT, ERalphaKO, and central E(2)- or ICI-treated ERalphaKO mice compared with that in intact WT mice given just ANG II. Together, these data indicate that ERalpha, especially central expression of the ER, mediates the protective effects of estrogen against ANG II-induced hypertension.

  15. Iron K$\\alpha$ emission in type-I and type-II Active Galactic Nuclei

    CERN Document Server

    Ricci, Claudio; Paltani, Stephane; Ichikawa, Kohei; Gandhi, Poshak; Awaki, Hisamitsu

    2014-01-01

    The narrow Fe K$\\alpha$ line is one of the main signatures of the reprocessing of X-ray radiation from the material surrounding supermassive black holes, and it has been found to be omnipresent in the X-ray spectra of active galactic nuclei (AGN). In this work we study the characteristics of the narrow Fe K$\\alpha$ line in different types of AGN. Using the results of a large Suzaku study we find that Seyfert 2s have on average lower Fe K$\\alpha$ luminosities than Seyfert 1s for the same 10-50 keV continuum luminosity. Simulating dummy Sy1s and Sy2s populations using physical torus models of X-ray reflected emission, we find that this difference can be explained by means of different average inclination angles with respect to the torus, as predicted by the unified model. Alternative explanations include differences in the intensities of Compton humps or in the photon index distributions. We show that the ratio between the flux of the broad and narrow Fe K$\\alpha$ line in the 6.35-6.45 keV range depends on the ...

  16. C IV and He II Line Emission of Lyman Alpha Blobs: Powered by Shock Heated Gas

    CERN Document Server

    Cabot, Samuel H C; Zheng, Zheng

    2016-01-01

    Utilizing {\\it ab initio} ultra-high resolution hydrodynamical simulations, we investigate the properties of the interstellar and circum-galactic medium of Ly$\\alpha$ Blobs (LABs) at $z=3$, focusing on three important emission lines: Ly$\\alpha$ 1216\\AA, \\heii 1640\\AA\\ and \\civ 1449\\AA. Their relative strengths provide a powerful probe of the thermodynamic properties of the gas when confronted with observations. By adjusting the dust attenuation effect using one parameter and matching the observed size-luminosity relation of LABs using another parameter, we show that our simulations can reproduce the observed \\civ/\\lya\\ and \\heii/\\lya\\ ratios adequately. This analysis provides the first successful physical model to account for simultaneously the LAB luminosity function, luminosity-size relation, and the \\civ/Ly$\\alpha$ and \\heii/Ly$\\alpha$ ratios, with only two parameters. The physical underpinning for this model is that, in addition to the stellar component for the \\lya\\ emission, the \\lya\\ and \\civ\\ emission...

  17. Localization of cyanobacterial photosystem II donor-side subunits by electron microscopy and the supramolecular organization of photosystem II in the thylakoid membrane

    NARCIS (Netherlands)

    Kuhl, Helena; Rögner, Matthias; Breemen, Jan F.L. van; Boekema, Egbert J.

    1999-01-01

    A large set of electron microscopy projections of photosystem II (PSII) dimers isolated from the cyanobacterium Synechococcus elongatus was characterized by single particle image analysis. In addition to previously published maps at lower resolution [Boekema, E.J., Hankamer, B., Bald, D., Kruip, J.,

  18. Association of polymorphisms in nicotinic acetylcholine receptor alpha 4 subunit gene (CHRNA4), mu-opioid receptor gene (OPRM1), and ethanol-metabolizing enzyme genes with alcoholism in Korean patients.

    Science.gov (United States)

    Kim, Soon Ae; Kim, Jong-Woo; Song, Ji-Young; Park, Sunny; Lee, Hee Jae; Chung, Joo-Ho

    2004-01-01

    Findings obtained from several studies indicate that ethanol enhances the activity of alpha4beta2 neuronal nicotinic acetylcholine receptor and support the possibility that a polymorphism of the nicotinic acetylcholine receptor alpha4 subunit gene (CHRNA4) modulates enhancement of nicotinic receptor function by ethanol. To identify the association between the CfoI polymorphism of the CHRNA4 and alcoholism, we examined distribution of genotypes and allele frequencies in Korean patients diagnosed with alcoholism (n = 127) and Korean control subjects without alcoholism (n = 185) with polymerase chain reaction-restriction fragment length polymorphism methods. We were able to detect the association between the CfoI polymorphism of the CHRNA4 and alcoholism in Korean patients (genotype P = .023; allele frequency P = .047). The genotypes and allele frequencies of known polymorphisms in other alcoholism candidate genes, such as alcohol metabolism-related genes [alcohol dehydrogenase 2 (ADH2), aldehyde dehydrogenase 2 (ALDH2), alcohol dehydrogenase 3 (ADH3), and cytochrome P450 2E1 (CYP2E1)] and mu-opioid receptor gene (OPRM1), were studied. The polymorphisms of ADH2, ALDH2, and CYP2E1 were significantly different in Korean patients with alcoholism and Korean control subjects without alcoholism, but ADH3 and OPRM1 did not differ between the two groups.

  19. Evaluation of [methyl-{sup 3}H]L655,708 and [ethyl-{sup 3}H]RY80 as putative PET ligands for central GABA{sub A} receptors containing {alpha}5 subunit

    Energy Technology Data Exchange (ETDEWEB)

    Opacka-Juffry, J. E-mail: jolanta@cu.rpms.ac.uk; Hirani, E.; Dawson, G.R.; Luthra, S.K.; Hume, S.P

    1999-10-01

    Two selective radioligands of gamma aminobutyric acid (GABA){sub A} receptors containing the {alpha}5 subunit, [{sup 3}H]L655,708 and [{sup 3}H]RY80, were evaluated in rats as potential in vivo tracers for positron emission tomography (PET). Brain uptake index (BUI), a measure of first pass extraction, was moderate for [{sup 3}H]L655,708 (BUI of 59%) and good for [{sup 3}H]RY80 (BUI of 96%). This finding was consistent with their in vitro binding to plasma proteins of {approx}76% and 50%, respectively. Following intravenous injection of either radioligand, radioactivity in plasma was measured and uptake characteristics were assessed in brain within a time period relevant to PET scanning (up to 90 min). Discrete brain regions, such as frontal cortex, striatum, hypothalamus, thalamus, hippocampus, colliculi, medulla, and cerebellum, were sampled and the temporal distribution of radioactivity analysed. Despite the reasonable delivery to the brain, neither of the radioligands had sufficient retention in the tissues rich in {alpha}5-containing GABA{sub A} receptors to achieve a good selective signal. For both radioligands, a maximal tissue:cerebellum ratio of 1.5 was seen in hippocampus at 10 min after injection. Thus, neither of the compounds studied shows potential for further development as an in vivo PET ligand.

  20. Regulation of topoisomerase II alpha and beta in HIV-1 infected and uninfected neuroblastoma and astrocytoma cells: involvement of distinct nordihydroguaretic acid sensitive inflammatory pathways.

    Science.gov (United States)

    Mandraju, Raj Kumar; Kondapi, Anand K

    2007-05-01

    The activity of Topoisomerase II alpha and beta isoforms is tightly regulated during different phases of cell cycle. In the present study, the action of anti-inflammatory agents, nordihydroguaretic acid (NDGA) is analyzed in HIV-1 infected CXCR4(+), CCR5(+) and CD4(-) SK-N-SH neuroblastoma, CXCR4(+), CCR5(+) and CD4(-) 1321N1 astrocytoma and CXCR4(+), CCR5(+/-) and CD4(-) GO-G-CCM glioblastoma cell lines. In SK-N-SH and 1321N1 the expression of Topoisomerase II alpha is concomitant with that of LOX-5 and is highly sensitive to NDGA, while the Topoisomerase II beta is expressed along with TNFalpha and exhibits low sensitivity to NDGA, suggesting distinct pathways of regulation for the two isoforms. HIV-1 infection in these cells enhanced the expression of Topo II alpha and beta. Further, the regulation of Topo II beta and TNFalpha in infected and uninfected SK cells is distinctly different. HIV-1 gp120 derived peptides could block HIV-1 mediated inflammation and Topoisomerase II alpha and beta expression, suggesting the viral mediated response. A combination of NDGA, gp-120 derived peptides and AZT has completely blocked the viral replication, suggesting the enhancement of potency of AZT under the suppression of inflammatory response. In contrast, the expression of Topo II alpha and beta was stimulated by NDGA in GO-G-CCM cells showing distinct regulatory pathway in these cells that was resistant to HIV-1 infection. This suggests the requirement of inflammatory response for productive viral infection. In summary, an induction of co-receptor mediated inflammatory response can distinctly enhance regulated expression of the cellular Topo II alpha and beta and promote productive infection in neurons and astrocytes.

  1. Synthesis of novel naphthoquinone-spermidine conjugates and their effects on DNA-topoisomerases I and II-{alpha}

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Andrea S.; Lima, Edson L.S.; Pinto, Angelo C.; Esteves-Souza, Andressa; Torrese, Jose C. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Quimica; Echevarria, Aurea [Universidade Federal Rural do Rio de Janeiro, RJ (Brazil). Dept. de Quimica; Camara, Celso A. [Paraiba Univ., Joao Pessoa, PB (Brazil). Lab. de Tecnologia Farmaceutica; Vargas, Maria D. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Quimica]. E-mail: mdvargas@vm.uff.br

    2006-05-15

    Novel derivatives of lapachol 2, nor-lapachol 3 and lawsone 4 have been synthesized by nucleophilic displacement of the methoxynaphthoquinones 2a, 3a and 4a with the polyamine (PA) N{sup 1}-Boc-N{sup 5}-Bn-spermidine 1a. The respective products 2b-4b were obtained in good yields and characterized by spectroscopic and analytical methods. The inhibitory action of these naphthoquinone-PA conjugates on DNA-topoisomerases (topo) I and II-{alpha} was evaluated by relaxation assay of supercoiled DNA plasmid. All compounds (1a 2b, 3b and 4b) presented significant inhibition of topo II-{alpha} catalytic activity at the 2 {mu}M dose. Considering that only PA 1a did not inhibit the enzyme catalytic activity at the 0.2 {mu}M dose, the appended naphthoquinone moiety acts as a 'value added' fragment. Compounds 1a 2b, 3b and 4b did not inhibit the enzyme DNA-topo I at the 200 {mu}M dose. (author)

  2. A detector module with highly efficient surface-alpha event rejection operated in CRESST-II Phase 2

    CERN Document Server

    Strauss, R; Bento, A; Bucci, C; Canonica, L; Erb, A; Feilitzsch, F v; Ferreiro, N; Gorla, P; Gütlein, A; Hauff, D; Jochum, J; Kiefer, M; Kluck, H; Kraus, H; Lanfranchi, J -C; Loebell, J; Münster, A; Petricca, F; Potzel, W; Pröbst, F; Reindl, F; Roth, S; Rottler, K; Sailer, C; Schäffner, K; Schieck, J; Scholl, S; Schönert, S; Seidel, W; Sivers, M v; Stanger, M; Stodolsky, L; Strandhagen, C; Tanzke, A; Uffinger, M; Ulrich, A; Usherov, I; Wawoczny, S; Willers, M; Wüstrich, M; Zöller, A

    2014-01-01

    The cryogenic dark matter experiment CRESST-II aims at the direct detection of WIMPs via elastic scattering off nuclei in scintillating CaWO$_4$ crystals. We present a new, highly improved, detector design installed in the current run of CRESST-II Phase 2 with an efficient active rejection of surface-alpha backgrounds. Using CaWO$_4$ sticks to hold the target crystal a detector housing with fully-scintillating inner surface could be realized. The presented detector (TUM40) provides an excellent threshold of ${\\sim}\\,0.60\\,$keV and a resolution of $\\sigma\\,{\\approx}\\,0.090\\,$keV (at 2.60$\\,$keV). With significantly reduced background levels, TUM40 sets stringent limits on the spin-independent WIMP-nucleon scattering cross section and probes a new region of parameter space for WIMP masses below 3$\\,$GeV/c$^2$. In this paper, we discuss the novel detector design and the surface-alpha event rejection in detail.

  3. PHASE I-II STUDY OF THE ADDITION OF ALPHA-2A INTERFERON TO 5-FLUOROURACIL LEUCOVORIN - PHARMACOKINETIC INTERACTION OF ALPHA-2A INTERFERON AND LEUCOVORIN

    NARCIS (Netherlands)

    SINNIGE, HAM; DEVRIES, EGE; UGES, DRA; ROENHORST, HW; VERSCHUEREN, RCJ; SLEIJFER, DT; WILLEMSE, PHB; MULDER, NH

    1993-01-01

    5-Fluorouracil (5-FU) activity has been improved by the use of leucovorin (LV) or alpha-2a interferon (alpha-IF). We investigated the feasibility and activity of addition of alpha-IF to a 5-FU/LV regimen. A phase I study with 26 patients (14 previously untreated, 12 previously treated) with dissemin

  4. The structural organization and immunohistochemistry of G-protein alpha subunits in the olfactory system of the air-breathing mudskipper, Periophthalmus barbarus (Linnaeus, 1766) (Gobiidae, Oxudercinae).

    Science.gov (United States)

    Kuciel, Michał; Rita Lauriano, Eugenia; Silvestri, Giuseppa; Zuwała, Krystyna; Pergolizzi, Simona; Zaccone, Daniele

    2014-01-01

    The study provides the first comprehensive information on the immunohistochemistry and ultrastructure of the olfactory receptor neurons (ORNs) in the mudskipper, Periophthalmus barbarus. The olfactory sensory epithelium is in the form of islets which cover part of the olfactory canal running from the upper lip toward the eye, where large single accessory nasal sacs occur. Within the islets, microvillous, ciliated and crypt ORNs were observed as well as giant cells and sparse non-sensory ciliated cells. Around the islets and in the walls of accessory nasal sacs, there are epidermal cells with microridges typical of fish epidermis. Close to the entrance to the accessory nasal sac, in the non-sensory epithelium of the nasal cavity and the skin epithelium covering the olfactory organ, areas of solitary chemosensory cells (SCCs) are reported for the first time. The distribution of the various ORN cell types is assessed through the immunohistochemistry against olfactory receptor coupled G-proteins. The ciliated ORNs were labeled by G alpha olf/s antibody. The ORNs with microvilli and crypt cells were G alpha i-3 immunoreactive.

  5. Transiting the Sun II: The impact of stellar activity on Lyman-$\\alpha$ transits

    CERN Document Server

    Llama, J

    2015-01-01

    High-energy observations of the Sun provide an opportunity to test the limits of our ability to accurately measure properties of transiting exoplanets in the presence of stellar activity. Here we insert transits of a hot Jupiter into continuous disk integrated data of the Sun in Lyman-alpha (Ly$\\alpha$) from NASA's SDO/EVE instrument to assess the impact of stellar activity on the measured planet-to-star radius ratio $(\\textrm{R}_\\textrm{p}/\\textrm{R}_\\star)$. In 75% of our simulated light curves we measure the correct radius ratio; however, incorrect values can be measured if there is significant short term variability in the light curve. The maximum measured value of $(\\textrm{R}_\\textrm{p}/\\textrm{R}_\\star)$ is $50\\%$ larger than the input value, which is much smaller than the large Ly$\\alpha$ transit depths that have been reported in the literature, suggesting that for stars with activity levels comparable to the Sun, stellar activity alone cannot account for these deep transits. We ran simulations withou...

  6. A case of subepidermal blistering disease with autoantibodies to multiple laminin subunits who developed later autoantibodies to alpha-5 chain of type IV collagen associated with membranous glomerulonephropathy.

    Science.gov (United States)

    Sueki, Hirohiko; Sato, Yoshinori; Ohtoshi, Shinpei; Nakada, Tokio; Yoshimura, Ashio; Tateishi, Chiharu; Borza, Dorin-Bogdan; Fader, William; Ghohestani, Reza F; Hirako, Yoshiaki; Koga, Hiroshi; Ishii, Norito; Tsuchisaka, Atsunari; Qian, Hua; Li, Xiaoguang; Hashimoto, Takashi

    2015-09-01

    We report a 68-year-old Japanese female patient with subepidermal blistering disease with autoantibodies to multiple laminins, who subsequently developed membranous glomerulonephropathy. At skin disease stage, immunofluorescence demonstrated IgG anti-basement membrane zone antibodies reactive with dermal side of NaCl-split skin. Immunoblotting of human dermal extract, purified laminin-332, hemidesmosome-rich fraction and laminin-521 trimer recombinant protein (RP) detected laminin γ-1 and α-3 and γ-2 subunits of laminin-332. Three years after skin lesions disappeared, nephrotic symptoms developed. Antibodies to α-3 chain of type IV collagen (COL4A3) were negative, thus excluding the diagnosis of Goodpasture syndrome. All anti-laminin antibodies disappeared. Additional IB and ELISA studies of RPs of various COL4 chains revealed reactivity with COL4A5, but not with COL4A6 or COL4A3. Although diagnosis of anti-laminin γ-1 (p200) pemphigoid or anti-laminin-332-type mucous membrane pemphigoid could not be made, this case was similar to previous cases with autoantibodies to COL4A5 and/or COL4A6.

  7. Proteolytic processing of the L-type Ca2+ channel alpha11.2 subunit in neurons [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Olivia R. Buonarati

    2017-07-01

    Full Text Available Background: The L-type Ca2+ channel Cav1.2 is a prominent regulator of neuronal excitability, synaptic plasticity, and gene expression. The central element of Cav1.2 is the pore-forming α11.2 subunit. It exists in two major size forms, whose molecular masses have proven difficult to precisely determine. Recent work suggests that α11.2 is proteolytically cleaved between the second and third of its four pore-forming domains (Michailidis et al,. 2014. Methods: To better determine the apparent molecular masses (MRof the α11.2 size forms, extensive systematic immunoblotting of brain tissue as well as full length and C-terminally truncated α11.2 expressed in HEK293 cells was conducted using six different region–specific antibodies against α11.2. Results: The full length form of α11.2 migrated, as expected, with an apparent MR of ~250 kDa. A shorter form of comparable prevalence with an apparent MR of ~210 kDa could only be detected in immunoblots probed with antibodies recognizing α11.2 at an epitope 400 or more residues upstream of the C-terminus. Conclusions: The main two size forms of α11.2 are the full length form and a shorter form, which lacks ~350 distal C-terminal residues. Midchannel cleavage as suggested by Michailidis et al. (2014 is at best minimal in brain tissue.

  8. Ser2 is the autophosphorylation site in the beta subunit from bicistronically expressed human casein kinase-2 and from native rat liver casein kinase-2 beta

    DEFF Research Database (Denmark)

    Boldyreff, B; James, P; Staudenmann, W;

    1993-01-01

    Human casein kinase-2 (CK-2) subunits alpha and beta were bicistronically expressed in bacteria. The recombinant holoenzyme shared all investigated properties with the native CK-2 from mammalian sources (rat liver, Krebs II mouse ascites tumour cells). Contrary to recombinant human CK-2 produced...

  9. An Organelle RNA Recognition Motif Protein Is Required for Photosystem II Subunit psbF Transcript Editing1[OPEN

    Science.gov (United States)

    Lucas, Meriah K.

    2017-01-01

    Loss-of-function mutations in ORGANELLE RNA RECOGNITION MOTIF PROTEIN6 (ORRM6) result in the near absence of RNA editing of psbF-C77 and the reduction in accD-C794 editing in Arabidopsis (Arabidopsis thaliana). The orrm6 mutants have decreased levels of photosystem II (PSII) proteins, especially PsbF, lower PSII activity, pale green pigmentation, smaller leaf and plant sizes, and retarded growth. Stable expression of ORRM6 rescues the orrm6 editing defects and mutant phenotype. Unlike ORRM1, the other known ORRM plastid editing factor, ORRM6, does not contain RNA editing interacting protein/multiple organellar RNA editing factor (RIP/MORF) boxes, which are required for ORRM1 to interact with site-specific pentatricopeptide repeat protein editing factors. ORRM6 interacts with RIP1/MORF8, RIP2/MORF2, and RIP9/MORF9, known components of RNA editosomes. While some plastid RRM proteins are involved in other forms of RNA processing and translation, the primary function of ORRM6 is evidently to mediate psbF-C77 editing, like the essential site-specific pentatricopeptide repeat protein LOW PSII ACCUMULATION66. Stable expression in the orrm6 mutants of a nucleus-encoded, plastid-targeted PsbF protein from a psbF gene carrying a T at nucleotide 77 significantly increases leaf and plant sizes, chlorophyll content, and PSII activity. These transformants demonstrate that plastid RNA editing can be bypassed through the expression of nucleus-encoded, edited forms of plastid genes. PMID:28213559

  10. An Organelle RNA Recognition Motif Protein Is Required for Photosystem II Subunit psbF Transcript Editing.

    Science.gov (United States)

    Hackett, Justin B; Shi, Xiaowen; Kobylarz, Amy T; Lucas, Meriah K; Wessendorf, Ryan L; Hines, Kevin M; Bentolila, Stephane; Hanson, Maureen R; Lu, Yan

    2017-04-01

    Loss-of-function mutations in ORGANELLE RNA RECOGNITION MOTIF PROTEIN6 (ORRM6) result in the near absence of RNA editing of psbF-C77 and the reduction in accD-C794 editing in Arabidopsis (Arabidopsis thaliana). The orrm6 mutants have decreased levels of photosystem II (PSII) proteins, especially PsbF, lower PSII activity, pale green pigmentation, smaller leaf and plant sizes, and retarded growth. Stable expression of ORRM6 rescues the orrm6 editing defects and mutant phenotype. Unlike ORRM1, the other known ORRM plastid editing factor, ORRM6, does not contain RNA editing interacting protein/multiple organellar RNA editing factor (RIP/MORF) boxes, which are required for ORRM1 to interact with site-specific pentatricopeptide repeat protein editing factors. ORRM6 interacts with RIP1/MORF8, RIP2/MORF2, and RIP9/MORF9, known components of RNA editosomes. While some plastid RRM proteins are involved in other forms of RNA processing and translation, the primary function of ORRM6 is evidently to mediate psbF-C77 editing, like the essential site-specific pentatricopeptide repeat protein LOW PSII ACCUMULATION66. Stable expression in the orrm6 mutants of a nucleus-encoded, plastid-targeted PsbF protein from a psbF gene carrying a T at nucleotide 77 significantly increases leaf and plant sizes, chlorophyll content, and PSII activity. These transformants demonstrate that plastid RNA editing can be bypassed through the expression of nucleus-encoded, edited forms of plastid genes.

  11. Effects of hippocampal injections of a novel ligand selective for the alpha 5 beta 2 gamma 2 subunits of the GABA/benzodiazepine receptor on Pavlovian conditioning.

    Science.gov (United States)

    Bailey, David J; Tetzlaff, Julie E; Cook, James M; He, Xiaohui; Helmstetter, Fred J

    2002-07-01

    Benzodiazepine pharmacology has led to greater insight into the neural mechanisms underlying learning and anxiety. The synthesis of new compounds capable of modulating responses produced by these receptors has been made possible by the development of an isoform model of the GABA(A)/benzodiazepine receptor complex. In the current experiment, rats were pretreated with several concentrations of the novel ligand RY024 (an alpha 5 beta 2 gamma 2 -selective benzodiazepine receptor inverse agonist) in the hippocampus and were trained in a Pavlovian fear conditioning paradigm. RY024 independently produced fear-related behavior prior to training and, at the highest concentration, decreased the strength of conditioning observed 24 h after training. These data provide further evidence for the involvement of hippocampal GABA(A)/benzodiazepine receptors in learning and anxiety.

  12. The largest subunit of RNA polymerase II as a new marker gene to study assemblages of arbuscular mycorrhizal fungi in the field.

    Directory of Open Access Journals (Sweden)

    Herbert Stockinger

    Full Text Available Due to the potential of arbuscular mycorrhizal fungi (AMF, Glomeromycota to improve plant growth and soil quality, the influence of agricultural practice on their diversity continues to be an important research question. Up to now studies of community diversity in AMF have exclusively been based on nuclear ribosomal gene regions, which in AMF show high intra-organism polymorphism, seriously complicating interpretation of these data. We designed specific PCR primers for 454 sequencing of a region of the largest subunit of RNA polymerase II gene, and established a new reference dataset comprising all major AMF lineages. This gene is known to be monomorphic within fungal isolates but shows an excellent barcode gap between species. We designed a primer set to amplify all known lineages of AMF and demonstrated its applicability in combination with high-throughput sequencing in a long-term tillage experiment. The PCR primers showed a specificity of 99.94% for glomeromycotan sequences. We found evidence of significant shifts of the AMF communities caused by soil management and showed that tillage effects on different AMF taxa are clearly more complex than previously thought. The high resolving power of high-throughput sequencing highlights the need for quantitative measurements to efficiently detect these effects.

  13. Glucosidase II β-subunit, a novel substrate for caspase-3-like activity in rice, plays as a molecular switch between autophagy and programmed cell death

    Science.gov (United States)

    Cui, Jing; Chen, Bing; Wang, Hongjuan; Han, Yue; Chen, Xi; Zhang, Wei

    2016-01-01

    Endoplasmic reticulum (ER) stress activates unfolded protein response (UPR) and autophagy. However, prolonged, severe stresses activate programmed cell death (PCD) in both animal and plant cells. Compared to the well-studied UPR pathway, the molecular mechanisms of ER-stress-induced PCD are less understood. Here, we report the identification of Gas2, the glucosidase II β subunit in the ER, as a potential switch between PCD and autophagy in rice. MS analysis identified Gas2, GRP94, and HSP40 protein in a purified caspase-3-like activity from heat stressed rice cell suspensions. The three corresponding genes were down-regulated under DTT-induced ER stress. Gas2 and GRP94 were localized to the ER, while HSP40 localized to the cytoplasm. Compared to wild-type, a Gas2 RNAi cell line was much sensitive to DTT treatment and had high levels of autophagy. Both caspase-3 and heat-stressed cell suspension lysate could cleave Gas2, producing a 14 kDa N-terminal fragment. Conditional expression of corresponding C-terminal fragment resulted in enhanced caspase-3-like activity in the protoplasts under heat stress. We proposed that mild ER stress causes down-regulation of Gas2 and induces autophagy, while severe stress results in Gas2 cleavage by caspase-3-like activity and the cleavage product amplifies this activity, possibly participating in the initiation of PCD. PMID:27538481

  14. Localization of eight additional genes in the human major histocompatibility complex, including the gene encoding the casein kinase II {beta} subunit (CSNK2B)

    Energy Technology Data Exchange (ETDEWEB)

    Albertella, M.R.; Jones, H.; Thomson, W. [Oxford Univ. (United Kingdom)] [and others

    1996-09-01

    A wide range of autoimmune and other diseases are known to be associated with the major histocompatibility complex. Many of these diseases are linked to the genes encoding the polymorphic histocompatibility complex. Many of these diseases are linked to the genes encoding the polymorphic histocompatibility antigens in the class I and class II regions, but some appear to be more strongly associated with genes in the central 1100-kb class III region, making it important to characterize this region fully for the presence of novel genes. An {approximately}220-kb segment of DNA in the class III region separating the Hsp70 (HSPA1L) and BAT1 (D6S8IE) genes, which was previously known to contain 14 genes. Genomic DNA fragments spanning the gaps between the known genes were used as probes to isolate cDNAs corresponding to five new genes within this region. Evidence from Northern blot analysis and exon trapping experiments that suggested the presence of at least two more new genes was also obtained. Partial cDNA and complete exonic genomic sequencing of one of the new genes has identified it as the casein kinase II{beta} subunit (CSNK2B). Two of the other novel genes lie within a region syntenic to that implicated in susceptibility to experimental allergic orchitis in the mouse, an autoimmune disease of the testis, and represent additional candidates for the Orch-1 locus associated with this disease. In addition, characterization of the 13-kb intergenic gap separating the RD (D6545) and G11 (D6S60E) genes has revealed the presence of a gene encoding a 1246-amino-acid polypeptide that shows significant sequence similarity to the yeast anti-viral Ski2p gene product. 49 refs., 8 figs.

  15. Fluorescently tagged laminin subunits facilitate analyses of the properties, assembly and processing of laminins in live and fixed lung epithelial cells and keratinocytes.

    Science.gov (United States)

    Hopkinson, Susan B; DeBiase, Phillip J; Kligys, Kristina; Hamill, Kevin; Jones, Jonathan C R

    2008-09-01

    Recent analyses of collagen, elastin and fibronectin matrix assembly, organization and remodeling have been facilitated by the use of tagged proteins that can be visualized without the need for antibody labeling. Here, we report the generation of C-terminal tagged, full-length and "processed" (alpha3DeltaLG4-5) human alpha3 as well as C-terminal tagged, full-length human beta3 laminin subunits in adenoviral vectors. Human epidermal keratinocytes (HEKs) and human bronchial epithelial (BEP2D) cells, which assemble laminin-332-rich matrices, as well as primary rat lung alveolar type II (ATII) cells, which elaborate a fibrous network rich in laminin-311, were infected with adenovirus encoding the tagged human laminin subunits. In HEKs and BEP2D cells, tagged, full-length alpha3, alpha3DeltaLG4-5 and beta3 laminin subunits incorporate into arrays of matrix organized into patterns that are comparable to those observed when such cells are stained using laminin-332 subunit antibody probes. Moreover, HEKs and BEP2Ds move over these tagged, laminin-332-rich matrix arrays. We have also used the tagged beta3 laminin subunit-containing matrices to demonstrate that assembled laminin-332 arrays influence laminin matrix secretion and/or assembly. In the case of rat ATII cells, although tagged alpha3 laminin subunits are not detected in the matrix of rat ATII cells infected with virus encoding full-length human alpha3 laminin protein, processed human alpha3 laminin subunits are incorporated into an extracellular fibrous array. We discuss how these novel laminin reagents can be used to study the organization, processing and assembly of laminin matrices and how they provide new insights into the potential functional importance of laminin fragments.

  16. Molecular cloning of the alpha subunit of complement component C8 (CpC8α) of whitespotted bamboo shark (Chiloscyllium plagiosum).

    Science.gov (United States)

    Wang, Ying; Zhang, Mengmeng; Wang, Conghui; Ye, Boping; Hua, Zichun

    2013-12-01

    Complement-mediated cytolysis is the important effect of immune response, which results from the assembly of terminal complement components (C5b-9). Among them, α subunit of C8 (C8α) is the first protein that traverses the lipid bilayer, and then initiates the recruitment of C9 molecules to form pore on target membranes. In this article, a full-length cDNA of C8α (CpC8α) is identified from the whitespotted bamboo shark (Chiloscyllium plagiosum) by RACE. The CpC8α cDNA is 2183 bp in length, encoding a protein of 591 amino acids. The deduced CpC8α exhibits 89%, 49% and 44% identity with nurse shark, frog and human orthologs, respectively. Sequence alignment indicates that the C8α is well conserved during the evolution process from sharks to mammals, with the same modular architecture as well as the identical cysteine composition in the mature protein. Phylogenetic analysis places CpC8α and nurse shark C8α in cartilaginous fish clade, in parallel with the teleost taxa, to form the C8α cluster with higher vertebrates. Hydrophobicity analysis also indicates a similar hydrophobicity of CpC8α to mammals. Finally, expression analysis revealed CpC8α transcripts were constitutively highly expressed in shark liver, with much less expression in other tissues. The well conserved structure and properties suggests an analogous function of CpC8α to mammalian C8α, though it remains to be confirmed by further study.

  17. Synthesis of 17beta-N-substituted 19-Nor-10-azasteroids as inhibitors of human 5alpha-reductases I and II.

    Science.gov (United States)

    Scarpi, Dina; Occhiato, Ernesto G; Danza, Giovanna; Serio, Mario; Guarna, Antonio

    2002-11-01

    The synthesis of 17beta-[N-(phenyl)methyl/phenyl-amido] substituted 10-azasteroids has been accomplished by either the TiCl4- or TMSOTf-catalysed reaction of carbamates 11 and 12 with Danishefsky's diene. The reaction provided 5alpha-H isomers 3a-5a and 5beta-H isomers 3b-5b depending on the reaction conditions. Both epimers of each compound were tested against human 5alpha-reductase types I and II. Unexpectedly, 5beta-H compounds were found more active than their 5alpha-H counterparts, the best inhibitors being 3b (IC50=279 and 2000 nM toward isoenzyme I and II, respectively) and 5b (IC50=913 and 247 nM toward isoenzymes I and II, respectively).

  18. Gravimetric determination and radiochemical separation of palladium(II) with ethyl-. cap alpha. -isonitrosoacetoacetate

    Energy Technology Data Exchange (ETDEWEB)

    Manwati, S.J.; Sawant, A.D. (Institute of Science, Bombay (India). Inorganic and Nuclear Chemistry Lab.)

    1984-10-01

    The use of ethyl-..cap alpha..-isonitrosoacetoacetate for the determination of palladium is reported. Pd can be estimated quantitatively from 0.5M to 2M HCl solution. Accurate results are obtained in 1M solution with an accuracy better than 1%. Decontamination values against platinum and other metals usually associated with Pd are greater than 10/sup 5/. The time required for gravimetric determination is about an hour, for radiochemical separation about 25 min and the recovery is better than 90%.

  19. The GLARE Survey II. Faint z=6 Ly-alpha Line Emitters in the HUDF

    CERN Document Server

    Stanway, Elizabeth R; Glazebrook, Karl; Abraham, Roberto G; Rhoads, James; Malhotra, Sangeeta; Crampton, David; Colless, Matthew; Chiu, Kuenley; 10.1111/j.1365-2966.2007.11469.x

    2008-01-01

    The galaxy population at z~6 has been the subject of intense study in recent years, culminating in the Hubble Ultra Deep Field (HUDF) -- the deepest imaging survey yet. A large number of high redshift galaxy candidates have been identified within the HUDF, but until now analysis of their properties has been hampered by the difficulty of obtaining spectroscopic redshifts for these faint galaxies. Our ''Gemini Lyman-Alpha at Reionisation Era'' (GLARE) project has been designed to undertake spectroscopic follow up of faint (z'5.5, and a further nine possible line emitters with detections at lower significance. We also place tight constraints on the equivalent width of Lyman-alpha emission for a further ten i'-drop galaxies and examine the equivalent width distribution of this faint spectroscopic sample of z~6 galaxies. We find that the fraction of galaxies with little or no emission is similar to that at z~3, but that the z~6 population has a tail of sources with high rest frame equivalent widths. Possible expla...

  20. A Novel Mechanism in Regulating the Alpha-Subunit of the Epithelial Sodium Channel (α ENaC by the Alternatively Spliced Form α ENaC-b

    Directory of Open Access Journals (Sweden)

    Marlene F. Shehata

    2009-01-01

    Full Text Available Introduction: In Dahl rats’ kidney cortex, the alternatively spliced form of the epithelial sodium channel α subunit (α ENaC-b is the most abundant mRNA transcript (32+/-3 fold α ENaC-wt as was investigated by quantitative RT-PCR analysis. α ENaC-b mRNA levels were significantly higher in Dahl R versus S rats, and were further augmented by high salt diet.Objectives: In the present study, we described the molecular cloning and searched for a possible role of α ENaC-b by testing its potential expression in COS7 cells as well as its impact on α ENaC-wt expression levels when co-expressed in COS7 cells in a dose-dependent manner.Methods: Using RT-PCR strategy, the full-length wildtype α ENaC transcript and the alternatively spliced form α ENaC-b were amplified, sequenced, cloned, subcloned into PCMV-sport6 expression vector, expressed and co-expressed into COS7 cells in a dose-dependent manner. A combination of denaturing and native western blotting techniques was employed to examine the expression of α ENaC-b in vitro, and to determine if an interaction between α ENaC-b and α ENaC-wt occurs in vitro, and finally to demonstrate if degradation of α ENaC-wt protein does occur.Results: α ENaC-b is translated in COS7 cells. Co-expression of α ENaC-b together with α ENaC-wt reduced α ENaC-wt levels in a dose-dependent manner. α ENaC-wt and α ENaC-b appear to form a complex that enhances the degradation of α ENaC-wt.Conclusions: Western blots suggest a novel mechanism in α ENaC regulation whereby α ENaC-b exerts a dominant negative effect on α ENaC-wt expression. This is potentially by sequestering α ENaC-wt, enhancing its proteolytic degradation, and possibly explaining the mechanism of salt-resistance in Dahl R rats.

  1. Effects of clonidine and alpha-adrenoceptor antagonists on motor activity in DSP4-treated mice II: interactions with apomorphine.

    Science.gov (United States)

    Fredriksson, A; Archer, T

    2000-04-01

    Adult mice were administered either the noradrenaline (NA) neurotoxin, N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP4) or distilled water (control), 10-12 days before motor activity testing, and 6 h before testing all the mice were administered reserpine (10 mg/kg), the monoamine-depleting agent. The interactive effects of (I) clonidine, the alpha(2)-adrenoceptor agonist, with the dopamine (DA) agonist, apomorphine, and the alpha(2)-antagonist, yohimbine, and (II) with either yohimbine or the alpha(1)-antagonist, prazosin, upon motor behaviour in activity test chambers were studied in reserpinized DSP4-treated and control mice. It was shown that apomorphine (3 mg/kg) increased locomotor and total activity in both reserpinized DSP4-treated and control mice but the effect was attenuated in the DSP4 mice. Co-administration of clonidine (3 mg/kg) with apomorphine potentiated the effects of apomorphine on motor activity and this effect was enhanced markedly by DSP4 pretreatment. Yohimbine (10 mg/kg) antagonized the motor activity-stimulating effects of apomorphine in both DSP4-treated and control mice. Co-administration of clonidine with apomorphine, following yohimbine, restored motor activity levels to those obtained in the absence of yohimbine and this effect upon locomotor activity was enhanced by DSP4 pretreatment. The effects of clonidine on motor activity were enhanced by NA-denervation. Prazzosin (3 mg/kg) enhanced the locomotor activity of both reserpinized DSP4-treated and control mice after the initial 30-min period but was not affected by DSP4 treatment. Analysis of post-decapitation convulsions (PDCs) indicated loss of the reflex by DSP4 pretreatment. Reserpine pretreatment abolished the initial, exploratory phase (30 min) of motor activity. These results demonstrate interactions between NA and DA systems that may bear eventual relevance to neurologic disorders such as parkinsonism.

  2. THE PRESENCE OF A B SUBUNIT INCREASES SENSITIVITY OF SODIUM CHANNEL NAV1.3, BUT NOT NAV1.2, TO TYPE II PYRETHROIDS.

    Science.gov (United States)

    Voltage-sensitive sodium channels (VSSCs) are a primary target of pyrethroid insecticides. VSSCs are comprised of a pore-forming ¿ and auxillary ß subunits, and multiple isoforms of both subunit types exist. The sensitivity of different isoform combinations to pyrethroids has not...

  3. Temperature-dependent structural changes in intrinsically disordered proteins: formation of alpha-helices or loss of polyproline II?

    DEFF Research Database (Denmark)

    Kjærgaard, Magnus; Nørholm, Ann-Beth; Hendus-Altenburger, Ruth;

    2010-01-01

    temperature, which most likely reflects formation of transient alpha-helices or loss of polyproline II (PPII) content. Using three IDPs, ACTR, NHE1, and Spd1, we show that the temperature-induced structural change is common among IDPs and is accompanied by a contraction of the conformational ensemble......Structural characterization of intrinsically disordered proteins (IDPs) is mandatory for deciphering their potential unique physical and biological properties. A large number of circular dichroism (CD) studies have demonstrated that a structural change takes place in IDPs with increasing....... This phenomenon was explored at residue resolution by multidimensional NMR spectroscopy. Intrinsic chemical shift referencing allowed us to identify regions of transiently formed helices and their temperature-dependent changes in helicity. All helical regions were found to lose rather than gain helical structures...

  4. Photometric H alpha and [O II] Luminosity Function of SDF and SXDF Galaxies: Implications for Future Baryon Oscillation Surveys

    CERN Document Server

    Sumiyoshi, Masanao; Oshige, Shunsuke; Glazebrook, Karl; Akiyama, Masayuki; Morokuma, Tomoki; Motohara, Kentaro; Shimasaku, Kazuhiro; Hayashi, Masao; Yoshida, Makiko; Kashikawa, Nobunari; Kodama, Tadayuki

    2009-01-01

    Efficient selection of emission line galaxies at z > 1 by photometric information in wide field surveys is one of the keys for future spectroscopic surveys to constrain dark energy using the baryon acoustic oscillation (BAO) signature. Here we estimate the H alpha and [O II] line luminosity functions of galaxies at z = 0.5-1.7 using a novel approach where multi-wavelength imaging data is used to jointly estimate both photometric redshifts and star-formation rates. These photometric estimates of line luminosities at high-redshift use the large data sets of the Subaru Deep Field and Subaru XMM-Newton Deep Field (covering \\sim 1 deg^2) and are calibrated with the spectroscopic data of the local Sloan Digital Sky Survey galaxies. The derived luminosity functions (especially H alpha) are in reasonable agreement with the past estimates based on spectroscopic or narrow-band-filter surveys. This dataset is useful for examining the photometric selection of target galaxies for BAO surveys because of the large cosmologi...

  5. A detector module with highly efficient surface-alpha event rejection operated in CRESST-II Phase 2

    Energy Technology Data Exchange (ETDEWEB)

    Strauss, R. [Max-Planck-Institut fuer Physik, Munich (Germany); Technische Universitaet Muenchen, Physik-Department, Garching (Germany); Angloher, G.; Ferreiro, N.; Hauff, D.; Kiefer, M.; Petricca, F.; Proebst, F.; Reindl, F.; Seidel, W.; Stodolsky, L.; Tanzke, A.; Wuestrich, M. [Max-Planck-Institut fuer Physik, Munich (Germany); Bento, A. [Universidade de Coimbra, CIUC, Departamento de Fisica, Coimbra (Portugal); Bucci, C.; Canonica, L.; Gorla, P.; Schaeffner, K. [Laboratori Nazionali del Gran Sasso, INFN, Assergi (Italy); Erb, A. [Technische Universitaet Muenchen, Physik-Department, Garching (Germany); Walther-Meissner-Institut fuer Tieftemperaturforschung, Garching (Germany); Feilitzsch, F. von; Guetlein, A.; Lanfranchi, J.C.; Muenster, A.; Potzel, W.; Roth, S.; Schoenert, S.; Stanger, M.; Ulrich, A.; Wawoczny, S.; Willers, M.; Zoeller, A. [Technische Universitaet Muenchen, Physik-Department, Garching (Germany); Jochum, J.; Loebell, J.; Rottler, K.; Sailer, C.; Scholl, S.; Strandhagen, C.; Uffinger, M.; Usherov, I. [Eberhard-Karls-Universitaet Tuebingen, Physikalisches Institut, Tuebingen (Germany); Kluck, H. [Institut fuer Hochenergiephysik der Oesterreichischen Akademie der Wissenschaften, Wien (Austria); Vienna University of Technology, Atominstitut, Wien (Austria); Kraus, H. [University of Oxford, Department of Physics, Oxford (United Kingdom); Schieck, J. [Institut fuer Hochenergiephysik der Oesterreichischen Akademie der Wissenschaften, Wien (Austria); Sivers, M. von [Technische Universitaet Muenchen, Physik-Department, Garching (Germany); University of Bern, Albert Einstein Center for Fundamental Physics, Bern (Switzerland)

    2015-08-15

    The cryogenic dark matter experiment CRESSTII aims at the direct detection of WIMPs via elastic scattering off nuclei in scintillating CaWO{sub 4} crystals. We present a new, highly improved, detector design installed in the current run of CRESST-II Phase 2 with an efficient active rejection of surface-alpha backgrounds. Using CaWO{sub 4} sticks instead of metal clamps to hold the target crystal, a detector housing with fully-scintillating inner surface could be realized. The presented detector (TUM40) provides an excellent threshold of ∝0.60 keV and a resolution of σ ∼ 0.090 keV (at 2.60 keV).With significantly reduced background levels, TUM40 sets stringent limits on the spin-independent WIMP nucleon scattering cross section and probes a new region of parameter space for WIMP masses below 3GeV/c{sup 2}. In this paper, we discuss the novel detector design and the surface-alpha event rejection in detail. (orig.)

  6. Interaction of alpha-lactalbumin with dimyristoyl phosphatidylcholine vesicles. II. A fluorescence polarization study.

    Science.gov (United States)

    Herreman, W; van Tornout, P; van Cauwelaert, F H; Hanssens, I

    1981-01-22

    The interaction of alpha-lactalbumin with dimyristoyl phosphatidylcholine vesicles was studied as a function of temperature, pH and the molar ratio of phospholipid to protein. The method consisted of measuring the fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene used as a probe embedded in the vesicles. After incubation of the protein with the phospholipid for 2 h at 23 degrees C, the polarization of the light emitted by this probe shifted to higher values; the shift was greater at acidic pH than at neutral pH. After incubation at 37 degrees C, no shift in polarization was found at pH 7, 6 and 5 while a strong increase occurred at pH 4. Lowering the temperature, after incubation at 37 degrees C, had little effect on the polarization at neutral pH. At pH 5, however, and in the transition range of the phospholipid, the polarization increased greatly. A kinetic study of the interaction carried out around the transition temperature of dimyristoyl phosphatidylcholine as a function of pH shows that the speed of complex formation between alpha-lactalbumin and the lipid increases from neutral to acidic pH. From the present results and in agreement with our earlier calorimetric and fluorescence data (Hanssens, I., Houthuys, C., Herreman, W. and van Cauwelaert, F.H. (1980) Biochim. Biophys, Acta 602, 539--557), it is concluded that at neutral pH the interaction mechanism is probably different from that at acidic pH. At neutral pH and at all temperatures, alpha-lactalbumin is mainly absorbed electrostatically to the outer surface of the vesicle with little or no influence on the transition temperature of the phospholipid. At this pH, only around the transition temperature is penetration possible. At pH 4, however, the protein is able to penetrate the vesicle at all temperatures and to interact hydrophobically with the phospholipid fatty acid chains. As a result of this interaction, the transition temperature is increased by about 4 degrees C. This different

  7. Evidence for multiple promoters of the human IL-5 receptor alpha subunit gene: a novel 6-base pair element determines cell-specific promoter function.

    Science.gov (United States)

    Zhang, J; Kuvelkar, R; Cheewatrakoolpong, B; Williams, S; Egan, R W; Billah, M M

    1997-12-01

    In addition to a previously characterized promoter (P1), we now show the existence of a second promoter for the human IL-5Ralpha gene. Initially, a genomic region (P2) 5' upstream of human IL-5Ralpha exon 2 was cloned by an inverted PCR. The transcriptional start site was then mapped to a deoxycytidine (C) residue within P2 by analyzing cellular mRNA with both the 5' rapid amplification of cDNA end-PCR and S1 nuclease protection assays. Transfection of eosinophilic HL-60 cells with reporter gene constructs in which either P1 or P2 was linked to the bacterial chloramphenicol acetyltransferase (CAT) gene resulted in CAT expression; little or no CAT expression occurred in other myeloid and nonmyeloid cell lines. Deletion studies showed that a 66-bp region, ranging from -31 to +35, was sufficient to promote CAT expression in eosinophilic HL-60 cells. Analysis of linker-scanning mutants identified a novel 6-bp element (5' CTAATT 3') spanning -19 to -14 that was essential for P2 promoter activity. In electrophoretic mobility shift assays, a P2 region from -31 to +1 containing the unique 6-bp element, when used as a probe, formed a complex with a protein(s) that was found only in the eosinophilic cell line. This binding activity was lost upon replacement of the 6-bp element with a 6-bp linker, suggesting that this element likely serves as the binding site for an eosinophilic HL-60 cell-specific transcription factor(s). Together, these data suggest an important role for P2 promoter in the regulation of eosinophil-specific expression of the human IL-5 receptor alpha gene.

  8. The interstellar medium near the sun. II - The line of sight to Alpha Virginis

    Science.gov (United States)

    York, D. G.; Kinahan, B. F.

    1979-01-01

    Measurements of the UV interstellar lines in Alpha Vir between 935 and 2960 A are reported. The derived abundances indicate significant depletion of Al, Si, Mn, Fe, and possibly Mg, whereas S, C, Ar, and O appear to be essentially undepleted. About half the gas is shown to be ionized, with a mean electron density of no more than 1 per cu cm, and the remainder is neutral, though both regions have the same velocity to within 2 km/s. A small fraction of the gas is apparently at a temperature of 400,000 K. The possibility of measuring the temperature of the H I gas is discussed, using the observed relationship between Doppler width and mass. A detailed discussion is included of the data analysis useful for comparatively simple lines of sight in terms of density, temperature, and extent of the possible physical regions, and of the relevant radiation field. An unidentified feature at 1063.2 A is reported.

  9. Dialkylamino cyclopentadienyl ruthenium(ii) complex-catalyzed alpha-alkylation of arylacetonitriles with primary alcohols.

    Science.gov (United States)

    Cheung, Hung Wai; Li, Juan; Zheng, Wenxu; Zhou, Zhongyuan; Chiu, Yu Hin; Lin, Zhenyang; Lau, Chak Po

    2010-01-07

    Aminocyclopentadienyl ruthenium complexes, [(eta(5)-C(5)H(4)NMe(2))Ru(PPh(3))(2)(CH(3)CN)](+)BF(4)(-) and [(eta(5)-C(5)H(4)NEt(2))Ru(PPh(3))(2)(CH(3)CN)](+)BF(4)(-), are moderately active catalysts for alpha-alkylation of arylacetonitriles with primary alcohols; on the other hand, the analogous unsubstituted cyclopentadienyl ruthenium complex [(eta(5)-C(5)H(5))Ru(PPh(3))(2)(CH(3)CN)](+)BF(4)(-) shows very low catalytic activity. On the basis of experimental results and theoretical calculations, rationalization for the much higher catalytic activity of the aminocyclopentadienyl complexes over that of the unsubstituted Cp complex is provided. In the catalytic systems with the former, it is possible to regenerate the active solvento complexes via protonation of the metal hydride intermediates and subsequent ligand substitution; this process is, however, very nonfacile in the catalytic system with the latter.

  10. Systemic radioimmunotherapy using a monoclonal antibody, anti-Tac directed toward the alpha subunit of the IL-2 receptor armed with the {alpha}-emitting radionuclides {sup 212}Bi or {sup 211}At

    Energy Technology Data Exchange (ETDEWEB)

    Wesley, Jon N.; McGee, Edwin C.; Garmestani, Kayhan; Brechbiel, Martin W.; Yordanov, Alexander T.; Wu Chuanchu; Gansow, Otto A.; Eckelman, William C.; Bacher, John D.; Flynn, Michael; Goldman, Carolyn K.; MacLin, Melvin; Schwartz, Uwe P.; Jackson-White, Terri; Phillip, Celeste M.; Decker, Jean; Waldmann, Thomas A. E-mail: tawald@helix.nih.gov

    2004-04-01

    To exploit the fact that IL-2 receptors are expressed by T-cells responding to foreign antigens but not by resting T-cells, humanized anti-Tac (HAT) armed with alpha-emitting radionuclides {sup 212}Bi and {sup 211}At was evaluated in a cynomolgus cardiac allograft model. Control graft survival was 8.2{+-} 0.5 days compared with 14.0{+-}1.3 days (p<0.01) survival for monkeys treated with {sup 212}Bi labeled HAT and 26.7{+-}2.4 days survival (p<0.001 versus controls) with {sup 211}At labeled HAT. Thus, {sup 211}At labeled HAT may have application in organ transplantation and in treatment of IL-2 receptor expressing T-cell leukemia.

  11. Shared receptor components but distinct complexes for alpha and beta interferons.

    Science.gov (United States)

    Lewerenz, M; Mogensen, K E; Uzé, G

    1998-09-25

    The type I interferon family includes 13 alpha, one omega and one beta subtypes recognized by a complex containing the receptor subunits ifnar1 and ifnar2 and their associated Janus tyrosine kinases, Tyk2 and Jak1. To investigate the reported differences in the way that alpha and beta interferons signal through the receptor, we introduced alanine-substitutions in the ifnar2 extracellular domain, and expressed the mutants in U5A cells, lacking endogenous ifnar2. A selection, designed to recover mutants that responded preferentially to alpha or beta interferon yielded three groups: I, neutral; II, sensitive to alpha interferon, partially resistant to beta interferon; III, resistant to alpha interferon, partially sensitive to beta interferon. A mutant clone, TMK, fully resistant to alpha interferon with good sensitivity to beta interferon, was characterized in detail and compared with U5A cells complemented with wild-type ifnar2 and also with Tyk2-deficient 11.1 cells, which exhibit a similar alpha-unresponsive phenotype with a partial beta interferon response. Using anti-receptor antibodies and mutant forms of beta interferon, three distinct modes of ligand interaction could be discerned: (i) alpha interferon with ifnar1 and ifnar2; (ii) beta interferon with ifnar1 and ifnar2; (iii) beta interferon with ifnar2 alone. We conclude that alpha and beta interferons signal differently through their receptors because the two ligand subtypes interact with the receptor subunits ifnar 1 and ifnar2 in entirely different ways.

  12. Induction of apoptosis in cholangiocarcinoma by an andrographolide analogue is mediated through topoisomerase II alpha inhibition.

    Science.gov (United States)

    Nateewattana, Jintapat; Dutta, Suman; Reabroi, Somrudee; Saeeng, Rungnapha; Kasemsook, Sakkasem; Chairoungdua, Arthit; Weerachayaphorn, Jittima; Wongkham, Sopit; Piyachaturawat, Pawinee

    2014-01-15

    Cholangiocarcinoma (CCA), the common primary malignant tumor of bile duct epithelial cells, is unresponsive to most chemotherapeutic drugs. Diagnosis with CCA has a poor prognosis, and therefore urgently requires effective therapeutic agents. In the present study we investigated anti-cancer effects of andrographolide analogue 3A.1 (19-tert-butyldiphenylsilyl-8, 17-epoxy andrographolide) and its mechanism in human CCA cell line KKU-M213 derived from a Thai CCA patient. By 24h after exposure, the analogue 3A.1 exhibited a potent cytotoxic effect on KKU-M213 cells with an inhibition concentration 50 (IC50) of approximately 8.0µM. Analogue 3A.1 suppressed DNA topoisomerase II α (Topo II α) protein expression, arrested the cell cycle at sub G0/G1 phase, induced cleavage of DNA repair protein poly (ADP-ribose) polymerases-1 (PARP-1), and enhanced expression of tumor suppressor protein p53 and pro-apoptotic protein Bax. In addition, analogue 3A.1 induced caspase 3 activity and inhibited cyclin D1, CDK6, and COX-2 protein expression. These results suggest that andrographolide analogue 3A.1, a novel topo II inhibitor, has significant potential to be developed as a new anticancer agent for the treatment of CCA.

  13. Genotypic to expression profiling of bovine calcium channel, voltage-dependent, alpha-2/delta subunit 1 gene, and their association with bovine mastitis among Frieswal (HFX Sahiwal) crossbred cattle of Indian origin.

    Science.gov (United States)

    Deb, Rajib; Singh, Umesh; Kumar, Sushil; Kumar, Arun; Singh, Rani; Sengar, Gyanendra; Mann, Sandeep; Sharma, Arjava

    2014-04-01

    Calcium channel, voltage-dependent, alpha-2/delta subunit 1 (CACNA2D1) gene is considered to be an important noncytokine candidate gene influencing mastitis. Scanty of reports are available until today regarding the role play of CACNA2D1 gene on the susceptibility of bovine mastitis. We interrogated the CACNA2D1 G519663A [A>G] SNP by PCR-RFLP among two hundreds Frieswal (HF X Sahiwal) crossbred cattle of Indian origin. Genotypic frequency of AA (51.5, n=101) was comparatively higher than AG (35, n=70) and GG (14.5, n=29). Association of Somatic cell score (SCS) with genotypes revealed that, GG genotypes showing lesser count (less susceptible to mastitis) compare to AA and AG. Relative expression of CACNA2D1 transcript (in milk samples) was significantly higher among GG than AG and AA. Further we have also isolated blood sample from the all groups and PBMCs were cultured from each blood sample as per the standard protocol. They were treated with Calcium channel blocker and the expression level of the CACNA2D1 gene was evaluated by Real Time PCR. Results show that expression level decline in each genotypic group after treatment and expression level of GG are again significantly higher than AA and AG. Thus, it may be concluded that GG genotypic animals are favorable for selecting disease resistant breeds.

  14. The human [gamma]-aminobutyric acid receptor subunit [beta]3 and [alpha]5 gene cluster in chromosome 15q11-q13 is rich in highly polymorphic (CA)[sub n] repeats

    Energy Technology Data Exchange (ETDEWEB)

    Glatt, K.; Lalande, M. (Howard Hughes Medical Institute, Boston, MA (United States)); Sinnett, D. (Harvard Medical School, Boston, MA (United States))

    1994-01-01

    The [gamma]-aminobutyric acid (GABA[sub A]) receptor [beta]33 (GABRB3) and [alpha]5 (GABRA5) subunit genes have been localized to the Angelman and Prader-Willi syndrome region of chromosome 15q11-q13. GABRB3, which encompasses 250 kb, is located 100 kb proximal of GABRA5, with the two genes arranged in head-to-head transcriptional orientation. In screening 135 kb of cloned DNA within a 260-kb interval extending from within GABRB3 to the 5[prime] end of GABRA5, 10 new (CA), repeats have been identified. Five of these have been analyzed in detail and found to be highly polymorphic, with the polymorphism information content (PIC) ranging from 0.7 to 0.85 and with heterozygosities of 67 to 94%. In the clones from GABRB3/GABRA5 region, therefore, the frequency of (CA)[sub n] with PICs [ge] 0.7 is 1 per 27 kb. Previous estimates of the density of (CA)[sub n] with PICs [ge] 0.7 in the human genome have been approximately 10-fold lower. The GABRB3/GABRA5 region appears, therefore, to be enriched for highly informative (CA)[sub n]. This set of closely spaced, short tandem repeat polymorphisms will be useful in the molecular analyses of Prader-Willi and Angelman syndromes and in high-resolution studies of genetic recombination within this region. 21 refs., 2 figs., 1 tab.

  15. A multilevel prediction of physiological response to challenge: Interactions among child maltreatment, neighborhood crime, endothelial nitric oxide synthase gene (eNOS), and GABA(A) receptor subunit alpha-6 gene (GABRA6).

    Science.gov (United States)

    Lynch, Michael; Manly, Jody Todd; Cicchetti, Dante

    2015-11-01

    Physiological response to stress has been linked to a variety of healthy and pathological conditions. The current study conducted a multilevel examination of interactions among environmental toxins (i.e., neighborhood crime and child maltreatment) and specific genetic polymorphisms of the endothelial nitric oxide synthase gene (eNOS) and GABA(A) receptor subunit alpha-6 gene (GABRA6). One hundred eighty-six children were recruited at age 4. The presence or absence of child maltreatment as well as the amount of crime that occurred in their neighborhood during the previous year were determined at that time. At age 9, the children were brought to the lab, where their physiological response to a cognitive challenge (i.e., change in the amplitude of the respiratory sinus arrhythmia) was assessed and DNA samples were collected for subsequent genotyping. The results confirmed that complex Gene × Gene, Environment × Environment, and Gene × Environment interactions were associated with different patterns of respiratory sinus arrhythmia reactivity. The implications for future research and evidence-based intervention are discussed.

  16. Ionized Gas in Damped Lyman Alpha Protogalaxies II. Comparison Between Models and the Kinematic Data

    CERN Document Server

    Wolfe, A M; Wolfe, Arthur M.

    2000-01-01

    We test semi-analytic models for galaxy formation with accurate kinematic data of damped Lyman alpha protogalaxies (DLAs) presented in the companion paper I. The models envisage centrifugally supported exponential disks at the centers of dark matter halos which are filled with ionized gas undergoing radial infall to the disks. The halo masses are drawn from cross-section weighted mass distributions predicted by CDM cosmogonies, or by the null hypothesis (TF model) that the dark matter mass distribution has not evolved since z ~ 3. In our models, C IV absorption lines detected in DLAs arise in infalling ionized clouds while the low-ion absorption lines arise from neutral gas in the disks. Using Monte Carlo methods we find: (a) The CDM models are incompatible with the low-ion statistics at more than 99% confidence whereas some TF models cannot be excluded at more than 88% confidence. (b) Both CDM and TF models agree with the observed distribution of C IV velocity widths. (c) The CDM models generate differences ...

  17. The role of the active site Zn in the catalytic mechanism of the GH38 Golgi alpha-mannosidase II: Implications from noeuromycin inhibition

    DEFF Research Database (Denmark)

    Bols, Mikael; Kuntz, Douglas A.; Rose, David R.

    2006-01-01

    Golgi alpha-mannosidase II (GMII) is a Family 38 glycosyl hydrolase involved in the eukaryotic N-glycosylation pathway in protein synthesis. Understanding of its catalytic mechanism has been of interest for the development of specific inhibitors that could lead to novel anti-metastatic or anti...

  18. Molecular Mechanism of AHSP-Mediated Stabilization of Alpha-Hemoglobin

    Energy Technology Data Exchange (ETDEWEB)

    Feng,L.; Gell, D.; Zhou, S.; Gu, L.; Kong, Y.; Li, J.; Hu, M.; Yan, N.; Lee, C.; et al.

    2005-01-01

    Hemoglobin A (HbA), the oxygen delivery system in humans, comprises two alpha and two beta subunits. Free alpha-hemoglobin (alphaHb) is unstable, and its precipitation contributes to the pathophysiology of beta thalassemia. In erythrocytes, the alpha-hemoglobin stabilizing protein (AHSP) binds alphaHb and inhibits its precipitation. The crystal structure of AHSP bound to Fe(II)-alphaHb reveals that AHSP specifically recognizes the G and H helices of alphaHb through a hydrophobic interface that largely recapitulates the alpha1-beta1 interface of hemoglobin. The AHSP-alphaHb interactions are extensive but suboptimal, explaining why beta-hemoglobin can competitively displace AHSP to form HbA. Remarkably, the Fe(II)-heme group in AHSP bound alphaHb is coordinated by the distal but not the proximal histidine. Importantly, binding to AHSP facilitates the conversion of oxy-alphaHb to a deoxygenated, oxidized [Fe(III)], nonreactive form in which all six coordinate positions are occupied. These observations reveal the molecular mechanisms by which AHSP stabilizes free alphaHb.

  19. Molecular requirements for MHC class II alpha-chain engagement and allelic discrimination by the bacterial superantigen streptococcal pyrogenic exotoxin C.

    Science.gov (United States)

    Kasper, Katherine J; Xi, Wang; Rahman, A K M Nur-Ur; Nooh, Mohammed M; Kotb, Malak; Sundberg, Eric J; Madrenas, Joaquín; McCormick, John K

    2008-09-01

    Superantigens (SAgs) are microbial toxins that bind to both TCR beta-chain variable domains (Vbetas) and MHC class II molecules, resulting in the activation of T cells in a Vbeta-specific manner. It is now well established that different isoforms of MHC II molecules can play a significant role in the immune response to bacterial SAgs. In this work, using directed mutational studies in conjunction with functional analyses, we provide a complete functional map of the low-affinity MHC II alpha-chain binding interface of the SAg streptococcal pyrogenic exotoxin C (SpeC) and identify a functional epitope in the beta-barrel domain that is required for the activation of T cells. Using cell lines that exclusively express individual MHC II isoforms, our studies provide a molecular basis for the selectivity of SpeC-MHC II recognition, and provide one mechanism by how SAgs are capable of distinguishing between different MHC II alleles.

  20. The Lyman alpha reference sample. II. Hubble space telescope imaging results, integrated properties, and trends

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, Matthew; Östlin, Göran; Duval, Florent; Sandberg, Andreas; Guaita, Lucia; Melinder, Jens; Rivera-Thorsen, Thøger [Department of Astronomy, Oskar Klein Centre, Stockholm University, AlbaNova University Centre, SE-106 91 Stockholm (Sweden); Adamo, Angela [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Schaerer, Daniel [Université de Toulouse, UPS-OMP, IRAP, F-31000 Toulouse (France); Verhamme, Anne; Orlitová, Ivana [Geneva Observatory, University of Geneva, 51 Chemin des Maillettes, CH-1290 Versoix (Switzerland); Mas-Hesse, J. Miguel; Otí-Floranes, Héctor [Centro de Astrobiología (CSIC-INTA), Departamento de Astrofísica, P.O. Box 78, E-28691 Villanueva de la Cañada (Spain); Cannon, John M.; Pardy, Stephen [Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States); Atek, Hakim [Laboratoire dAstrophysique, École Polytechnique Fédérale de Lausanne (EPFL), Observatoire, CH-1290 Sauverny (Switzerland); Kunth, Daniel [Institut d' Astrophysique de Paris, UMR 7095, CNRS and UPMC, 98 bis Bd Arago, F-75014 Paris (France); Laursen, Peter [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Herenz, E. Christian, E-mail: matthew@astro.su.se [Leibniz-Institut für Astrophysik (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany)

    2014-02-10

    We report new results regarding the Lyα output of galaxies, derived from the Lyman Alpha Reference Sample, and focused on Hubble Space Telescope imaging. For 14 galaxies we present intensity images in Lyα, Hα, and UV, and maps of Hα/Hβ, Lyα equivalent width (EW), and Lyα/Hα. We present Lyα and UV radial light profiles and show they are well-fitted by Sérsic profiles, but Lyα profiles show indices systematically lower than those of the UV (n ≈ 1-2 instead of ≳ 4). This reveals a general lack of the central concentration in Lyα that is ubiquitous in the UV. Photometric growth curves increase more slowly for Lyα than the far ultraviolet, showing that small apertures may underestimate the EW. For most galaxies, however, flux and EW curves flatten by radii ≈10 kpc, suggesting that if placed at high-z only a few of our galaxies would suffer from large flux losses. We compute global properties of the sample in large apertures, and show total Lyα luminosities to be independent of all other quantities. Normalized Lyα throughput, however, shows significant correlations: escape is found to be higher in galaxies of lower star formation rate, dust content, mass, and nebular quantities that suggest harder ionizing continuum and lower metallicity. Six galaxies would be selected as high-z Lyα emitters, based upon their luminosity and EW. We discuss the results in the context of high-z Lyα and UV samples. A few galaxies have EWs above 50 Å, and one shows f{sub esc}{sup Lyα} of 80%; such objects have not previously been reported at low-z.

  1. Isophotes of a field in the Cygnus loop photographed in the (O III) and (N II)+H. cap alpha. lines

    Energy Technology Data Exchange (ETDEWEB)

    Sitnik, T.G.; Toropova, M.S.

    1982-11-01

    From interference-filter image-tube photographs of a 9' field in the western part of the Cygnus Loop supernova remnant, taken in the lambda5007 (O III) and lambdalambda 6584, 6563 (N II) + H..cap alpha.. lines, sets of isophotes are derived by an equidensitometry technique based on the Sabattier effect. The emission regions in these lines exhibit a relative displacement, interpreted as evidence for radiative cooling of the gas behind the shock generated in the supernova outburst. An explanation is offered for the differing morphology of the nebular filaments in the (O III) and (N II) + H..cap alpha.. lines. The anomalously high I/sub Otsi/II/I/sub H/..beta.. intensity ratio may reflect a spatial separation of the corresponding emission zones.

  2. Inhibin subunits, follistatin and activin receptors in the human teratocarcinoma cell line Tera-2.

    Science.gov (United States)

    de Jong, F H; de Winter, J P; Wesseling, J G; Timmerman, M A; van Genesen, S; van den Eijnden-van Raaij, A J; van Zoelen, E J

    1993-05-14

    The expression of mRNAs for inhibin subunits was studied in the human teratocarcinoma cell line Tera-2 clone 13 before and after differentiation with retinoic acid (RA). Both alpha- and beta B-subunits of inhibin were expressed. Subsequently, inhibin bio- and immunoactivity in the conditioned media of the Tera-2 cells were determined by studying the release of follicle-stimulating hormone from rat pituitary cells, by immunoassay and by immunoprecipitation using inhibin alpha- and beta B-subunit specific antibodies. Strikingly dissimilar high bio- and low immuno-activities were found. The ensuing hypothesis that the high bioactivity might be due to the presence of the activin-binding protein follistatin was confirmed by immunoprecipitation of 34 and 37 kDa labelled proteins, using a polyclonal anti-follistatin antiserum after culture of the Tera-2 cells with [35S]-methionine. Furthermore, expression of activin receptor types II and IIB mRNA was found in the cells. Addition of 5 microM RA to monolayer cultures of Tera-2 cells resulted in differentiation to flat endoderm-like cells and caused a slight suppression of the expression of the mRNA encoding the inhibin alpha- and beta B-subunits. The expression of follistatin and activin receptor type IIB was strongly suppressed, whereas the expression of the activin receptor type II was not affected. We conclude that Tera-2 cells secrete follistatin and express inhibin subunits and activin receptors differentially during RA-induced differentiation. The role of the decreased expression of follistatin and activin receptor IIB mRNA after addition of RA in the mechanism of RA-induced differentiation remains to be elucidated.

  3. Mutant U5A cells are complemented by an interferon-alpha beta receptor subunit generated by alternative processing of a new member of a cytokine receptor gene cluster.

    Science.gov (United States)

    Lutfalla, G; Holland, S J; Cinato, E; Monneron, D; Reboul, J; Rogers, N C; Smith, J M; Stark, G R; Gardiner, K; Mogensen, K E

    1995-10-16

    The cellular receptor for the alpha/beta interferons contains at least two components that interact with interferon. The ifnar1 component is well characterized and a putative ifnar2 cDNA has recently been identified. We have cloned the gene for ifnar2 and show that it produces four different transcripts encoding three different polypeptides that are generated by exon skipping, alternative splicing and differential use of polyadenylation sites. One polypeptide is likely to be secreted and two are transmembrane proteins with identical extracellular and transmembrane domains but divergent cytoplasmic tails of 67 and 251 amino acids. A mutant cell line U5A, completely defective in IFN-alpha beta binding and response, has been isolated and characterized. Expression in U5A cells of the polypeptide with the long cytoplasmic domain reconstitutes a functional receptor that restores normal interferon binding, activation of the JAK/STAT signal transduction pathway, interferon-inducible gene expression and antiviral response. The IFNAR2 gene maps at 0.5 kb from the CRFB4 gene, establishing that together IFNAR2, CRFB4, IFNAR1 and AF1 form a cluster of class II cytokine receptor genes on human chromosome 21.

  4. Functional expression and characterization of a Xenopus laevis peptidylglycine alpha-amidating monooxygenase, AE-II, in insect-cell culture.

    Science.gov (United States)

    Suzuki, K; Ohta, M; Okamoto, M; Nishikawa, Y

    1993-04-01

    The alpha-amidating reaction of peptide hormones is a two-step process which is catalyzed by peptidylglycine alpha-hydroxylating monooxygenase (PHM) and peptidylhydroxyglycine N-C lyase (PHL). There are three types of mRNA for these amidating enzymes in Xenopus laevis, namely AE-I, AE-II and AE-III. AE-I encodes only PHM and AE-III encodes both PHM and PHL. AE-II seems to encode subtypes of both PHM and PHL. While AE-II mRNA is present in high amounts in frog skin, the actual enzymes originating from AE-II have not been detected. When we expressed AE-II in cultured insect-cells using the baculovirus expression vector system, the expressed enzyme was specifically localized to the membrane fraction due to its hydrophobic transmembrane domain. Alternatively, when the transmembrane-domain-deleted AE-II (Met1-Ile731) was expressed, the enzyme was secreted into the culture medium; this secreted enzyme was purified to homogeneity by a simple two-step procedure. We have verified that the reaction product of the purified enzyme was the amidated peptide, indicating that AE-II has the ability to catalyze the entire amidating reaction.

  5. Transcriptional regulation of the nuclear gene encoding the alpha-subunit of the mammalian mitochondrial F1F0 ATP synthase complex: role for the orphan nuclear receptor, COUP-TFII/ARP-1.

    Science.gov (United States)

    Jordan, Elzora M; Worley, Teri; Breen, Gail A M

    2003-03-11

    Our laboratory has been studying the transcriptional regulation of the nuclear gene (ATPA) that encodes the alpha-subunit of the mammalian mitochondrial F1F0 ATP synthase complex. We have previously determined that the regulatory factor, upstream stimulatory factor 2 (USF2), can stimulate transcription of the ATPA gene through the cis-acting regulatory element 1 in the upstream promoter of this gene. In this study, we used the yeast one-hybrid screening method to identify another factor, COUP-TFII/ARP-1, which also binds to the ATPA cis-acting regulatory element 1. Binding of the orphan nuclear receptor, COUP-TFII/ARP-1, to the ATPA regulatory element 1 was confirmed using electrophoretic mobility shift experiments, and COUP-TFII/ARP-1-containing complexes were detected in HeLa cell nuclear extracts. A mutational analysis indicated that the binding site for COUP-TFII/ARP-1 in the ATPA regulatory element 1 is an imperfect direct repeat of a nuclear receptor response element (A/GGGTCA) with a spacer of three nucleotides. Functional assays in HeLa cells showed that COUP-TFII/ARP-1 represses the ATPA promoter activity in a dose- and sequence-dependent manner. Furthermore, cotransfection assays demonstrated that COUP-TFII/ARP-1 inhibits the USF2-mediated activation of the wild-type ATPA gene promoter but not a mutant promoter that is defective in COUP-TFII/ARP-1-binding. Overexpression of USF2 reversed the COUP-TFII/ARP-1-mediated repression of the ATPA promoter. Mobility shift assays revealed that COUP-TFII/ARP-1 and USF2 compete for binding to the ATPA regulatory element 1. Thus, the ATPA gene is regulated by a multifunctional binding site through which the transcription factors, COUP-TFII/ARP-1 and USF2, bind and exert their antagonistic effects.

  6. Comparison of denaturation by guanidine hydrochloride of the wild type tryptophan synthase alpha-subunit of Escherichia coli and two mutant protein (Glu 49 replaced by Met or Gln).

    Science.gov (United States)

    Yutani, K; Ogasahara, K; Suzuki, M; Sugino, Y

    1979-04-01

    In order to elucidate the roles of individual amino acid residues in the conformational stability of proteins, the denaturation by guanidine hydrochloride of the wild-type trytophan synthase alpha-subunit of Escherichia coli and two mutant proteins, trpA33 (Glu 49 leads to Met) and trpA11 (Glu 49 leads to Gln), has been compared by means of CD measurements at pH 7.0 and various temperatures. CD spectra of the two mutant proteins were similar to that of the wild-type protein. The trpA33 and the trpA11 proteins were more and less resistant, respectively, to guanidine hydrochloride than the wild-type protein at 9.7 to 49.6 degrees C. The free energy change of unfolding in water delta delta Gnd H2O, was evaluated assuming a three state denaturation, since the denaturation curves of three proteins suggested the presence of one stable intermediate. The values of delta Gnd H2O for the trpA33, the wild-type, and the trpA11 proteins at 25.8 degrees C and pH 7.0 were 13.4,8.8, and 6.3 kcal/mol, respectively. The delta Gnd H2O of the trpA11 protein was almost independent of temperature, though that of the trpA33 protein was remarkably dependent on temperature. The conformation stabilities of the three proteins were correlated with the hydrophobicities of the substituted amino acid residues.

  7. Gene fusions with human carbonic anhydrase II for efficient expression and rapid single-step recovery of recombinant proteins: expression of the Escherichia coli F1-ATPase epsilon subunit.

    Science.gov (United States)

    Van Heeke, G; Shaw, R; Schnizer, R; Couton, J M; Schuster, S M; Wagner, F W

    1993-08-01

    A new expression vector was constructed which allows the overproduction in Escherichia coli of tripartite proteins consisting of human carbonic anhydrase isozyme II (hCAII), a peptide linker containing an enterokinase cleavage site, and a target protein of interest. Carbonic anhydrase is soluble and stable in E. coli and serves as a highly specific purification tag in the recovery of the fusion protein by a single affinity chromatography step. The enterokinase cleavage site was engineered into the construct to allow accurate and efficient release of the target protein. To demonstrate the practical value of this vector, the E. coli F1-ATPase epsilon subunit was expressed as a fusion with hCAII. After a single purification step, biologically active recombinant E. coli F1-ATPase epsilon subunit was recovered following proteolytic removal of the hCAII moiety.

  8. Oscillations of the sun's chromosphere. II - H-alpha line centre and wing filtergram time sequences

    Science.gov (United States)

    Kneer, F.; von Uexkuell, M.

    1985-03-01

    In order to investigate the dynamics of the solar chromosphere we perform a Fourier analysis of time sequences (total duration 128 min) of Hα photographic filtergrams taken simultaneously at disc centre in line centre and ±0.5 Å from the line centre. The results are: (i) At low frequencies (periods >450 s) the brightness fluctuations are caused by the temporal evolution of Hα structures at the boundaries of the chromospheric network. We observe that much of the coarse chromospheric structure survives the 128 min time span. We derive lifetimes of 2-8 min for the small-scale structure and 5-20 min for the larger structures. (ii) The modal structure of the 5 min oscillation is clearly visible in the power spectra of the three filtergram. The fundamental (f) mode can be followed to high horizontal wavenumbers kh ≍3.7 Mm-1 and follows the expected relationship ω2f = gkh, where g is the surface gravity. (iii) A chromospheric resonant mode cannot be found in the k - ω plane. (iv) The higher resonant p modes reach into the acoustic wave domain (periods T ≍ 150 s) and thus require the transition zone as the upper reflecting layer. (v) We find no evidence for internal gravity waves. (vi) From a coherence and phase analysis we conclude that the brightness fluctuations of the chromospheric structure seen in -0.5 Å lead those in +0.5 Å by 2 min at kh =2 Mm -1 and by 4 min at kh =0.5 Mm-1. (vii) From the same coherence and phase analysis we can identify acoustic waves in the solar atmosphere with periods as short as 80 s. They possess as much power as the 5 min oscillations and are seen better outside the chromospheric network than within the network. (viii) The phase difference between intensity in Hα line centre and velocity, constructed from the two Hα wing filtergrams, decreases from about 90° at low frequencies and high wavenumbers to 0° at high frequencies and low wavenumbers. Tentatively we interpret this as a change from mainly standing waves for the low

  9. Topoisomerase II alpha and p27; alternative markers to decide on the proliferation capacity of astrocytic tumors

    Directory of Open Access Journals (Sweden)

    Evrim ÖZTÜRK

    2008-05-01

    Full Text Available Proliferation capacity is an important parameter which enables us to predict the prognosis of tumours. Many immunohistochemical studies were conducted to search the relation of proliferative capacity with different clinical and histological parameters. Ki67 is a well known immunohistochemical marker of proliferation and some standard values have been established for Ki67 indexes of astrocytic tumours. For this purpose, considering the roles of proteins in cell cycle, some immunohistochemical markers other than Ki67 can be suggested. In this study, expressions of topoisomerase II alpha, a nuclear protein in mitotically active cells and p27, a cylin-dependent kinase inhibitor, were correlated with the grade and Ki67 indexes of 67 astrocytomas. Topoisomerase expressions demonstrated an increase with increasing grade. It also followed a parallel curve with Ki67. On the other hand, p27 had an inverse correlation with the tumor grade. The cut-off value for topoisomerase was calculated to vary 3.5% between low and high grade tumours. No cut-off value could be obtained for p27.

  10. 1. alpha. ,25-dihydroxyvitamin D sub 3 regulates the expression of carbonic anhydrase II in nonerythroid avian bone marrow cells

    Energy Technology Data Exchange (ETDEWEB)

    Billecocq, A.; Emanuel, J.R.; Levenson, R.; Baron, R. (Yale Univ. School of Medicine, New Haven, CT (USA))

    1990-08-01

    1{alpha},25-Dihydroxyvitamin D{sub 3} (1,25(OH){sub 2}D{sub 3}), the active metabolite of the steroid hormone vitamin D, is a potent regulator of macrophage and osteoclast differentiation. The mature osteoclast, unlike the circulating monocyte or the tissue macrophage, expresses high levels of carbonic anhydrase II (CAII). This enzyme generates protons and bicarbonate from water and carbon dioxide and is involved in bone resorption and acid-base regulation. To test whether 1,25(OH){sub 2}D{sub 3} could induce the differentiation of myelomonocytic precursors toward osteoclasts rather than macrophages, analyzed its effects on the expression of CAII in bone marrow cultures containing precursors common to both cell types. The expression of CAII was markedly increased by 1,25(OH){sub 2}D{sub 3} in a dose-and time-dependent manner. In bone marrow, this increase occurred at the mRNA and protein levels and was detectable as early as 24 hr after stimulation. 1,25(OH){sub 2}D{sub 3} was also found to induce CAII expression in a transformed myelomonocytic avian cell line. These results suggest that 1,25(OH){sub 2}D{sub 3} regulates the level at which myelomonocytic precursors express CAII, an enzyme that is involved in the function of the mature osteoclast.

  11. Age-related effects on verbal and visuospatial memory are mediated by theta and alpha II rhythms.

    Science.gov (United States)

    Reichert, Johanna Louise; Kober, Silvia Erika; Witte, Matthias; Neuper, Christa; Wood, Guilherme

    2016-01-01

    Both electrical brain activity during rest and memory functions change across the lifespan. Moreover, electrical brain activity is associated with memory functions. However, the interplay between all these effects has been investigated only scarcely. The present study investigated the extent to which the power of resting-state electroencephalographic (EEG) frequencies mediates the impact of aging on verbal and visuospatial memory. Seventy healthy participants with 22 to 83years of age completed a visuospatial and verbal learning and memory test and provided eyes-open and eyes-closed resting-state EEG data. Robust age-related effects on behavioral and EEG data were observed. Mediation analyses showed that the relative power of the theta (4-8Hz) frequency band in fronto-central locations partly explained the negative age-related effect on delayed recall in the verbal memory task. The relative power of the alpha II (10-12Hz) frequency band in mainly parietal locations partly explained the negative impact of age on immediate and delayed recall in the visuospatial task. Results indicate that spontaneous brain activity carries specific information about aging processes and predicts the level of competence in verbal and visuospatial memory tasks.

  12. Insulin-like growth factors (IGFs) stimulate the release of alpha 1-antichymotrypsin and soluble IGF-II/mannose 6-phosphate receptor from MCF7 breast cancer cells.

    Science.gov (United States)

    Confort, C; Rochefort, H; Vignon, F

    1995-09-01

    The growth of hormone-responsive MCF7 human breast cancer cells is controlled by steroid hormones and growth factors. By metabolic labeling of cells grown in steroid- and growth factor-stripped serum conditions, we show that insulin-like growth factors (IGF-I and IGF-II) increase by approximately 5-fold the release of several proteins including cathepsin D, alpha 1-antichymotrypsin, and soluble forms of the multifunctional IGF-II/mannose 6-phosphate (M6P) receptor. Two soluble forms of IGF-II/M6P receptors were detected, one major (approximately 260 kilodaltons) and one minor (approximately 85 kilodaltons) that probably represents a proteolytic fragment of the larger soluble molecule. IGFs increased receptor release in a dose-dependent fashion with 50-60% of newly synthesized receptor released at 5-10 nM IGFs. The release of IGF-II/M6P receptors correlated with the levels of secreted cathepsin D in different human breast cancer cells or in rats stable transfectants that are constitutively expressing variable levels of human cathepsin D. IGFs had a stronger effect on IGF-II/M6P receptor release, whereas estradiol treatment preferentially enhanced the release of protease and antiprotease. We thus demonstrate that in human breast cancer cells, IGFs not only act as strong mitogens but also regulate release of alpha 1-antichymotrypsin, IGF-II/M6P-soluble receptor, and cathepsin D; three proteins that potentially regulate cell proliferation and/or invasion.

  13. Twenty-two novel mutations in the lysosomal alpha-glucosidase gene (GAA) underscore the genotype-phenotype correlation in glycogen storage disease type II.

    Science.gov (United States)

    Hermans, Monique M P; van Leenen, Dik; Kroos, Marian A; Beesley, Clare E; Van Der Ploeg, Ans T; Sakuraba, Hitoshi; Wevers, Ron; Kleijer, Wim; Michelakakis, Helen; Kirk, Edwin P; Fletcher, Janice; Bosshard, Nils; Basel-Vanagaite, Lina; Besley, Guy; Reuser, Arnold J J

    2004-01-01

    Patients with glycogen storage disease type II (GSDII, Pompe disease) suffer from progressive muscle weakness due to acid alpha-glucosidase deficiency. The disease is inherited as an autosomal recessive trait with a spectrum of clinical phenotypes. We have investigated 29 cases of GSDII and thereby identified 55 pathogenic mutations of the acid alpha-glucosidase gene (GAA) encoding acid maltase. There were 34 different mutations identified, 22 of which were novel. All of the missense mutations and two other mutations with an unpredictable effect on acid alpha-glucosidase synthesis and function were transiently expressed in COS cells. The effect of a novel splice-site mutation was investigated by real-time PCR analysis. The outcome of our analysis underscores the notion that the clinical phenotype of GSDII is largely dictated by the nature of the mutations in the GAA alleles. This genotype-phenotype correlation makes DNA analysis a valuable tool to help predict the clinical course of the disease.

  14. FtmOx1, a non-heme Fe(II) and alpha-ketoglutarate-dependent dioxygenase, catalyses the endoperoxide formation of verruculogen in Aspergillus fumigatus.

    Science.gov (United States)

    Steffan, Nicola; Grundmann, Alexander; Afiyatullov, Shamil; Ruan, Hanli; Li, Shu-Ming

    2009-10-07

    Verruculogen is a tremorgenic mycotoxin and contains an endoperoxide bond. In this study, we describe the cloning, overexpression and purification of a non-heme Fe(ii) and alpha-ketoglutarate-dependent dioxygenase FtmOx1 from Aspergillus fumigatus, which catalyses the conversion of fumitremorgin B to verruculogen by inserting an endoperoxide bond between two prenyl moieties. Incubation with (18)O(2)-enriched atmosphere demonstrated that both oxygen atoms of the endoperoxide bond are derived from one molecule of O(2). FtmOx1 is the first endoperoxide-forming non-heme Fe(ii) and alpha-ketoglutarate-dependent dioxygenase reported so far. A mechanism of FtmOx1-catalysed verruculogen formation is postulated and discussed.

  15. Isophotes of a field in the Cygnus Loop photographed in the forbidden O III and forbidden N II + H-alpha lines

    Science.gov (United States)

    Sitnik, T. G.; Toropova, M. S.

    1982-12-01

    From interference-filter image-tube photographs of a 9 arc min field in the western part of the Cygnus Loop supernova remnant, taken in the 5007 forbidden O III and 6584, 6563 forbidden N II + H-alpha lines, sets of isophotes are derived by an equidensitometry technique based on the Sabattier effect. The emission regions in these lines exhibit a relatively displacement, interpreted as evidence for radiative cooling of the gas behind the shock generated in the supernova outburst. An explanation is offered for the differing morphology of the nebular filaments in the forbiddden O III and forbidden N II + H-alpha lines. The anomalously high I (O III)/I(H-beta) intensity ratio may reflect a spatial separation of the corresponding emission zones.

  16. Clinical evaluation of serum alpha-fetoprotein (AFP) and protein induced by vitamin K absence or antagonist-II (PIVKA-II) levels in patients with hepatocellular carcinoma following interventional radiology.

    Science.gov (United States)

    Minakuchi, K; Murata, K; Kaminoh, T; Takada, K; Takashima, S; Nakamura, K; Onoyama, Y

    1993-01-01

    Fourteen patients with unrespectable HCC were treated with various interventional radiology (IVR) procedures. The initial therapeutic response was determined using computed tomography (CT) findings, and determinations of serum alpha-fetoprotein (AFP) and protein induced by Vitamin K absence or antagonist-II (PIVKA-II) levels. When CT studies of the initial response to IVR were compared with changes in the serum AFP and PIVKA-II levels, the AFP level was found to correlate more closely than the PIVKA-II levels. The PIVKA-II level correlated more closely than the AFP level in cases with poor response to IVR. Both of these tumor markers should be measured in combination with the diagnostic imagings for follow-up studies of IVR.

  17. Electronic spectra and photophysics of platinum(II) complexes with alpha-diimine ligands - Solid-state effects. I - Monomers and ligand pi dimers

    Science.gov (United States)

    Miskowski, Vincent M.; Houlding, Virginia H.

    1989-01-01

    Two types of emission behavior for Pt(II) complexes containing alpha-diimine ligands have been observed in dilute solution. If the complex also has weak field ligands such as chloride, ligand field (d-d) excited states become the lowest energy excited states. If only strong field ligands are present, a diimine 3(pi-pi/asterisk/) state becomes the lowest. In none of the cases studied did metal-to-ligand charge transfer excited state lie lowest.

  18. Mechanism of promoter selection by RNA polymerase II: mammalian transcription factors alpha and beta gamma promote entry of polymerase into the preinitiation complex.

    Science.gov (United States)

    Conaway, R C; Garrett, K P; Hanley, J P; Conaway, J W

    1991-07-15

    Productive binding of RNA polymerase II at the core region of TATA box-containing promoters is controlled by the action of the TATA factor and four additional transcription factors, designated alpha, beta gamma, delta, and epsilon, which have each been purified to near homogeneity from rat liver. This process is accomplished in three distinguishable stages. In the first stage (initial complex formation), the core promoter is packaged with the TATA factor into a binary complex that serves as the recognition site for RNA polymerase II. Here we show that, in the second stage (site selection), transcription factors alpha and beta gamma act in combination to promote selective binding of RNA polymerase II to the initial complex. Several lines of evidence argue that alpha and beta gamma function at this stage by a mechanism related to that utilized by bacterial sigma factors. In the third stage, transcription factors delta and epsilon promote assembly of the functional preinitiation complex. Our evidence supports the model that delta and epsilon enter the preinitiation complex and direct formation of stable protein-DNA contacts that anchor the transcription apparatus to the core promoter at sequences near the cap site.

  19. Topoisomerase II alpha expression and the benefit of adjuvant chemotherapy for postoperative patients with non-small cell lung cancer

    Directory of Open Access Journals (Sweden)

    Jie Li

    2010-11-01

    Full Text Available Abstract Background Adjuvant chemotherapy has been shown to improve survival rates of postoperative patients with non-small cell lung cancer (NSCLC. Biomarkers could help select an appropriate chemotherapy for NSCLC patients or predict the efficacy of chemotherapy. The objective of this study was to explore the possible prognostic and predictive role of topoisomerase II alpha (TopIIα expression level in postoperative NSCLC patients who received adjuvant chemotherapy. Methods Patients with stage I-III NSCLC, who underwent surgery in our hospital from January 2004 to December 2007 and who also received adjuvant chemotherapy after surgery, were analyzed in this study. Expression of TopIIα and Ki67 in paraffin-embedded tissues was detected by immunohistochemistry (IHC. The relationships between clinicopathological characteristics, chemotherapy regimens, the expression of biomarkers and disease free survival (DFS were analyzed. Results TopIIα and Ki67 were highly expressed in 22.5% and 36.4% of the 151 patients, respectively. Univariate survival analysis showed that male sex (P = 0.036, non-adenocarcinoma (P = 0.004, earlier pathological TNM stage (P = 0.001 or pathological N stage (P Conclusions High TopIIα expression was discovered to be correlated with better DFS for postoperative NSCLC patients who received adjuvant chemotherapy. The NVB-containing chemotherapy regimen was more effective than the TXT-containing regimen in improving DFS in patients with low TopIIα expression. TopIIα could be considered to be an independent prognostic biomarker of DFS in postoperative NSCLC patients who received adjuvant chemotherapy.

  20. [Clinical features and acid alpha-glucosidase gene mutation in 7 Chinese patients with glycogen storage disease type II].

    Science.gov (United States)

    Liu, Qi; Zhao, Juan; Wang, Zhao-xia; Zhang, Wei; Yuan, Yun

    2013-07-02

    To explore the clinical features and acid alpha-glucosidase (GAA) gene mutations of Chinese patients with glycogen storage disease typeII(GSDII). Seven patients with GSDII were diagnosed by muscle pathology examination at Department of Neurology, Peking University First Hospital from 2003 to 2011. One patient with infant-onset presented development retardation, generalized muscle weakness, dyspnea, cardiomegaly and hepatomegaly. Six cases were of late-onset ranging from 1 to 29 years. Their main clinical features included progressive muscle weakness. Two patients developed respiratory insufficiency. Increased serum creatine kinase was detected in all of them. Electromyography studies showed myopathic (n = 5) and neuropathic (n = 1) changes. Muscle biopsies showed basophilic vacuoles in muscle fibers containing a large amounts of glycogen on electron microscopy. GAA gene mutation was detected by direct sequencing of polymerase chain reaction (PCR) product. Novel mutations were screened in 100 normal controls. GAA gene mutations were found in all of them, including 10 point mutations and 1 frameshift deletion. Six mutations (p. P361L, p. P266S, p.R437C, p.R600C, p.W746S and p.W746*) have been reported before. And five novel mutations (p.R168Q, p.R168P, p.E521V, p.R594H and c.827_845del) were found in this study. None of these novel mutations were found in 100 normal controls except for p.R168Q mutation in two normal controls. p. P361L and p.W746* were detected in two unrelated GSDII patients while other mutations were carried by only one patient. In our study, we found several novel GAA mutations in Chinese patients with GSDII. No hot spot mutation of GAA gene existed in our patient group. However, p. P266S, p. P361L and p.R437C might be associated with late-onset GSDII.

  1. MicroRNA-139 suppresses proliferation in luminal type breast cancer cells by targeting Topoisomerase II alpha

    Energy Technology Data Exchange (ETDEWEB)

    Hua, Wei [Department of Obstetrics and Gynecology, Xijing Hospital, Fourth Military Medical University, Xi' an 710032 (China); State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, 710032 Xi' an (China); Sa, Ke-Di; Zhang, Xiang; Jia, Lin-Tao; Zhao, Jing [State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, 710032 Xi' an (China); Yang, An-Gang [State Key Laboratory of Cancer Biology, Department of Immunology, Fourth Military Medical University, 710032 Xi' an (China); Zhang, Rui, E-mail: ruizhang@fmmu.edu.cn [State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, 710032 Xi' an (China); Fan, Jing, E-mail: jingfan@fmmu.edu.cn [Department of Vascular and Endocrine Surgery, Xijing Hospital, Fourth Military Medical University, Xi' an 710032 (China); Bian, Ka, E-mail: kakamax85@hotmail.com [State Key Laboratory of Cancer Biology, Department of Immunology, Fourth Military Medical University, 710032 Xi' an (China); Department of Otolaryngology, Tangdu Hospital, Fourth Military Medical University, Xi' an 710038 (China)

    2015-08-07

    The classification of molecular subtypes of breast cancer improves the prognostic accuracy and therapeutic benefits in clinic. However, because of the complexity of breast cancer, more biomarkers and functional molecules need to be explored. Here, analyzing the data in a huge cohort of breast cancer patients, we found that Topoisomerase II alpha (TOP2a), an important target of chemotherapy is a biomarker for prognosis in luminal type breast cancer patients, but not in basal like or HER2 positive breast cancer patients. We identified that miR-139, a previous reported anti-metastatic microRNA targets 3’-untranslated region (3′UTR) of TOP2a mRNA. Further more, we revealed that the forced expression of miR-139 reduces the TOP2a expression at both mRNA and protein levels. And our functional experiments showed that the ectopic expression of miR-139 remarkably inhibits proliferation in luminal type breast cancer cells, while exogenous TOP2a expression could rescue inhibition of cell proliferation mediated by miR-139. Collectively, our present study demonstrates the miR-139-TOP2a regulatory axis is important for proliferation in luminal type breast cancer cells. This functional link may help us to further understand the specificity of subtypes of breast cancer and optimize the strategy of cancer treatment. - Highlights: • High levels of TOP2a expression are closely associated with poor prognosis in luminal type breast cancer patients. • TOP2a is a novel target of miR-139. • Overexpression of miR-139 inhibits proliferation in luminal type breast cancer cells. • TOP2a is essential for miR-139-induced growth arrest in luminal type breast cancer cells.

  2. alpha1-acid glycoprotein as a putative biomarker for monitoring the development of the type II reactional stage of leprosy.

    Science.gov (United States)

    Gupta, Nishma; Shankernarayan, Nallakandy P; Dharmalingam, Kuppamuthu

    2010-04-01

    Leprosy, a spectral disease manifested on the basis of host immune responses, is complicated by its reactional stages, namely type I reversal reaction (RR) and type II erythema nodosum leprosum (ENL). These reactional stages are characterized by uncontrolled and aberrant immune responses. Biomarkers for reactional stages would aid in early diagnosis, efficient treatment, prevention of neurological complications and prediction of predisposition to reactional stages. In this study, comparative analysis of the serum proteome of leprosy patients by two-dimensional electrophoresis (2DE) followed by mass spectrometry showed differential expression of acute-phase protein alpha (1)-acid glycoprotein (AGP; also known as orosomucoid). AGP levels in untreated ENL cases were significantly higher than in lepromatous leprosy (LL; a non-reactional disease stage) (P=0.0126), RR (P=0.0176) and healthy controls (P=0.0030). These data were confirmed using ELISA. The levels of AGP decreased to normal levels after treatment with multidrug therapy and thalidomide (P =0.0167). In a follow-up study, AGP levels, which were high in the untreated ENL stage, decreased significantly at 5 days ( P=0.0084) and 21 days (P=0.0027) post-treatment. A stage-dependent increase in AGP in an LL patient who progressed into the ENL stage was also shown. Glycosylation analysis by 2DE showed differential expression of acidic glycoforms of AGP in untreated ENL cases. Changes in AGP concentration and differential expression of isoforms correlated with the inflammatory condition in ENL and also with the treatment regimen. Thus, initial validation of AGP as an ENL-specific biomarker and treatment indicator was shown in this study.

  3. PRESENT-DAY DESCENDANTS OF z = 3 Ly{alpha}-EMITTING GALAXIES IN THE MILLENNIUM-II HALO MERGER TREES

    Energy Technology Data Exchange (ETDEWEB)

    Walker-Soler, Jean P.; Gawiser, Eric [Physics and Astronomy Department, Rutgers University, Piscataway, NJ 08854 (United States); Bond, Nicholas A. [Goddard Space Flight Center, Astrophysics Science Division, Observational Cosmology Laboratory, Greenbelt, MD 20771 (United States); Padilla, Nelson; Francke, Harold, E-mail: jpwalker@physics.rutgers.edu [Pontificia Universidad Catolica de Chile, Facultad de Fisica, Santiago (Chile)

    2012-06-20

    Using the Millennium-II Simulation dark matter sub-halo merger histories, we created mock catalogs of Ly{alpha}-emitting (LAE) galaxies at z = 3.1 to study the properties of their descendants. Several models were created by selecting the sub-halos to match the number density and typical dark matter mass determined from observations of these galaxies. We used mass-based and age-based selection criteria to study their effects on descendant populations at z {approx_equal} 2, 1, and 0. For the models that best represent LAEs at z = 3.1, the z = 0 descendants have a median dark matter halo mass of 10{sup 12.7} M{sub Sun }, with a wide scatter in masses (50% between 10{sup 11.8} and 10{sup 13.7} M{sub Sun }). Our study differentiated between central and satellite sub-halos and found that {approx}55% of z = 0 descendants are central sub-halos with M{sub Median} {approx} 10{sup 12}. This confirms that central z = 0 descendants of z = 3.1 LAEs have halo masses typical of L*-type galaxies. The satellite sub-halos reside in group/cluster environments with dark matter masses around 10{sup 14} M{sub Sun }. The median descendant mass is robust to various methods of age determination, but it could vary by a factor of five due to current observational uncertainties in the clustering of LAEs used to determine their typical z = 3.1 dark matter mass.

  4. Alpha II Spectrin breakdown products in immature Sprague Dawley rat hippocampus and cortex after traumatic brain injury.

    Science.gov (United States)

    Schober, Michelle E; Requena, Daniela F; Davis, Lizeth J; Metzger, Ryan R; Bennett, Kimberly S; Morita, Denise; Niedzwecki, Christian; Yang, Zhihui; Wang, Kevin K W

    2014-07-29

    After traumatic brain injury (TBI), proteolysis of Alpha II Spectrin by Calpain 1 produces 145 Spectrin breakdown products (SBDPs) while proteolysis by Caspase 3 produces 120 SBDPs. 145 and 120 SBDP immunoblotting reflects the relative importance of caspase-dependent apoptosis or calpain-dependent excitotoxic/necrotoxic cell death in brain regions over time. In the adult rat, controlled cortical impact (CCI) increased 120 SBDPs in the first hours, lasting a few days, and increased 145 SBDPs within the first few days lasting up to 14 days after injury. Little is known about SBDPs in the immature brain after TBI. Since development affects susceptibility to apoptosis after TBI, we hypothesized that CCI would increase 145 and 120 SBDPs in the immature rat brain relative to SHAM during the first 3 and 5 days, respectively. SBDPs were measured in hippocampi and cortices at post injury days (PID) 1, 2, 3, 5, 7 and 14 after CCI or SHAM surgery in the 17 day old Sprague Dawley rat. 145 SBDPs increased in both brain tissues ipsilateral to injury during the first 3 days, while changes in contralateral tissues were limited to PID2 cortex. 145 SBDPs elevations were more marked and enduring in hippocampus than in cortex. Against expectations, 120 SBDPs only increased in PID1 hippocampus and PID2 cortex. 145 SBDPs elevations occurred early after CCI, similar to previous studies in the adult rat, but resolved more quickly. The minimal changes in 120 SBDPs suggest that calpain-dependent, but not caspase-dependent, cell death predominates in the 17 day old rat after CCI. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Protein engineering of the archetypal nitroarene dioxygenase of Ralstonia sp. strain U2 for activity on aminonitrotoluenes and dinitrotoluenes through alpha-subunit residues leucine 225, phenylalanine 350, and glycine 407.

    Science.gov (United States)

    Keenan, Brendan G; Leungsakul, Thammajun; Smets, Barth F; Mori, Masa-aki; Henderson, David E; Wood, Thomas K

    2005-05-01

    Naphthalene dioxygenase (NDO) from Ralstonia sp. strain U2 has not been reported to oxidize nitroaromatic compounds. Here, saturation mutagenesis of NDO at position F350 of the alpha-subunit (NagAc) created variant F350T that produced 3-methyl-4-nitrocatechol from 2,6-dinitrotoluene (26DNT), that released nitrite from 23DNT sixfold faster than wild-type NDO, and that produced 3-amino-4-methyl-5-nitrocatechol and 2-amino-4,6-dinitrobenzyl alcohol from 2-amino-4,6-dinitrotoluene (2A46DNT) (wild-type NDO has no detectable activity on 26DNT and 2A46DNT). DNA shuffling identified the beneficial NagAc mutation G407S, which when combined with the F350T substitution, increased the rate of NDO oxidation of 26DNT, 23DNT, and 2A46DNT threefold relative to variant F350T. DNA shuffling of NDO nagAcAd also generated the NagAc variant G50S/L225R/A269T with an increased rate of 4-amino-2-nitrotoluene (4A2NT; reduction product of 2,4-dinitrotoluene) oxidation; from 4A2NT, this variant produced both the previously uncharacterized oxidation product 4-amino-2-nitrocresol (enhanced 11-fold relative to wild-type NDO) as well as 4-amino-2-nitrobenzyl alcohol (4A2NBA; wild-type NDO does not generate this product). G50S/L225R/A269T also had increased nitrite release from 23DNT (14-fold relative to wild-type NDO) and generated 2,3-dinitrobenzyl alcohol (23DNBA) fourfold relative to wild-type NDO. The importance of position L225 for catalysis was confirmed through saturation mutagenesis; relative to wild-type NDO, NDO variant L225R had 12-fold faster generation of 4-amino-2-nitrocresol and production of 4A2NBA from 4A2NT as well as 24-fold faster generation of nitrite and 15-fold faster generation of 23DNBA from 23DNT. Hence, random mutagenesis discovered two new residues, G407 and L225, that influence the regiospecificity of Rieske non-heme-iron dioxygenases.

  6. The vertebrate ancestral repertoire of visual opsins, transducin alpha subunits and oxytocin/vasopressin receptors was established by duplication of their shared genomic region in the two rounds of early vertebrate genome duplications.

    Science.gov (United States)

    Lagman, David; Ocampo Daza, Daniel; Widmark, Jenny; Abalo, Xesús M; Sundström, Görel; Larhammar, Dan

    2013-11-02

    Vertebrate color vision is dependent on four major color opsin subtypes: RH2 (green opsin), SWS1 (ultraviolet opsin), SWS2 (blue opsin), and LWS (red opsin). Together with the dim-light receptor rhodopsin (RH1), these form the family of vertebrate visual opsins. Vertebrate genomes contain many multi-membered gene families that can largely be explained by the two rounds of whole genome duplication (WGD) in the vertebrate ancestor (2R) followed by a third round in the teleost ancestor (3R). Related chromosome regions resulting from WGD or block duplications are said to form a paralogon. We describe here a paralogon containing the genes for visual opsins, the G-protein alpha subunit families for transducin (GNAT) and adenylyl cyclase inhibition (GNAI), the oxytocin and vasopressin receptors (OT/VP-R), and the L-type voltage-gated calcium channels (CACNA1-L). Sequence-based phylogenies and analyses of conserved synteny show that the above-mentioned gene families, and many neighboring gene families, expanded in the early vertebrate WGDs. This allows us to deduce the following evolutionary scenario: The vertebrate ancestor had a chromosome containing the genes for two visual opsins, one GNAT, one GNAI, two OT/VP-Rs and one CACNA1-L gene. This chromosome was quadrupled in 2R. Subsequent gene losses resulted in a set of five visual opsin genes, three GNAT and GNAI genes, six OT/VP-R genes and four CACNA1-L genes. These regions were duplicated again in 3R resulting in additional teleost genes for some of the families. Major chromosomal rearrangements have taken place in the teleost genomes. By comparison with the corresponding chromosomal regions in the spotted gar, which diverged prior to 3R, we could time these rearrangements to post-3R. We present an extensive analysis of the paralogon housing the visual opsin, GNAT and GNAI, OT/VP-R, and CACNA1-L gene families. The combined data imply that the early vertebrate WGD events contributed to the evolution of vision and the

  7. Predicting Lyman-alpha and Mg II Fluxes from K and M Dwarfs Using GALEX Ultraviolet Photometry

    CERN Document Server

    Shkolnik, Evgenya L; Peacock, Sarah; Barman, Travis S

    2014-01-01

    A star's UV emission can greatly affect the atmospheric chemistry and physical properties of closely orbiting planets with the potential for severe mass loss. In particular, the Lyman-alpha emission line at 1216 Angstroms, which dominates the far-ultraviolet spectrum, is a major source of photodissociation of important atmospheric molecules such as water and methane. The intrinsic flux of Lyman-alpha, however, cannot be directly measured due to the absorption of neutral hydrogen in the interstellar medium and contamination by geocoronal emission. To date, reconstruction of the intrinsic Lyman-alpha line based on Hubble Space Telescope spectra has been accomplished for 46 FGKM nearby stars, 28 of which have also been observed by the Galaxy Evolution Explorer (GALEX). Our investigation provides a correlation between published intrinsic Lyman-alpha and GALEX far- and near-ultraviolet chromospheric fluxes for K and M stars. The negative correlations between the ratio of the Lyman-alpha to the GALEX fluxes reveal ...

  8. Protein kinase A type I activates a CRE-element more efficiently than protein kinase A type II regardless of C subunit isoform

    Directory of Open Access Journals (Sweden)

    Kvissel Anne-Katrine

    2011-02-01

    Full Text Available Abstract Background Protein kinase A type I (PKAI and PKAII are expressed in most of the eukaryotic cells examined. PKA is a major receptor for cAMP and specificity is achieved partly through tissue-dependent expression and subcellular localization of subunits with different biochemical properties. In addition posttranslational modifications help fine tune PKA activity, distribution and interaction in the cell. In spite of this the functional significance of two forms of PKA in one cell has not been fully determined. Here we have tested the ability of PKAI and PKAII formed by expression of the regulatory (R subunits RIα or RIIα in conjunction with Cα1 or Cβ2 to activate a co-transfected luciferace reporter gene, controlled by the cyclic AMP responsive element-binding protein (CREB in vivo. Results We show that PKAI when expressed at equal levels as PKAII was significantly (p Conclusion We suggest that differential effects of PKAI and PKAII in inducing Cre-luciferace activity depend on R and not C subunit identity.

  9. Chemical chaperones improve transport and enhance stability of mutant alpha-glucosidases in glycogen storage disease type II.

    Science.gov (United States)

    Okumiya, Toshika; Kroos, Marian A; Vliet, Laura Van; Takeuchi, Hiroaki; Van der Ploeg, Ans T; Reuser, Arnold J J

    2007-01-01

    Glycogen storage disease type II (GSDII; Pompe disease or acid maltase deficiency) is an autosomal recessive disorder caused by lysosomal acid alpha-glucosidase (AalphaGlu) deficiency and manifests predominantly as skeletal muscle weakness. Defects in post-translational modification and transport of mutant AalphaGlu species are frequently encountered and may potentially be corrected with chaperone-mediated therapy. In the present study, we have tested this hypothesis by using deoxynojirimycin and derivatives as chemical chaperones to correct the AalphaGlu deficiency in cultured fibroblasts from patients with GSDII. Four mutant phenotypes were chosen: Y455F/Y455F, P545L/P545L, 525del/R600C and D645E/R854X. In case of Y455F/Y455F and P545L/P545L, N-(n-butyl)deoxynojirimycin (NB-DNJ) restored the transport, maturation and activity of AalphaGlu in a dose dependent manner, while it had no effect on the reference enzyme beta-hexosaminidase. NB-DNJ promoted export from the endoplasmic reticulum (ER) to the lysosomes and stabilized the activity of mutant AalphaGlu species, Y455F and P545L, inside the lysosomes. In long-term culture, the AalphaGlu activity in the fibroblasts from the patients with mutant phenotypes, Y455F/Y455F and P545L/P545L, increased up to 14.0- and 7.9-fold, respectively, in the presence of 10mumol/L NB-DNJ. However, the effect of NB-DNJ on Y455F/Y455F subsided quickly after removal of the compound. We conclude that NB-DNJ acts in low concentration as chemical chaperone for certain mutant forms of AalphaGlu that are trapped in the ER, poorly transported or labile in the lysosomal environment. Chemical chaperone therapy could create new perspectives for therapeutic intervention in GSDII.

  10. Estrogen receptor binding radiopharmaceuticals: II. Tissue distribution of 17. cap alpha. -methylestradiol in normal and tumor-bearing rats

    Energy Technology Data Exchange (ETDEWEB)

    Feenstra, A.; Vaalburg, W.; Nolten, G.M.J.; Reiffers, S.; Talma, A.G.; Wiegman, T.; van der Molen, H.D.; Woldring, M.G.

    1983-06-01

    Tritiated 17..cap alpha..-methylestradiol was synthesized to investigate the potential of the carbon-11-labeled analog as an estrogen-receptor-binding radiopharmaceutical. In vitro, 17..cap alpha..-methylestradiol is bound with high affinity to the cytoplasmic estrogen receptor from rabbit uterus (K/sub d/ = 1.96 x 10/sup -10/M), and it sediments as an 8S hormone-receptor complex in sucrose gradients. The compound shows specific uptake in the uterus of the adult rat, within 1 h after injection. In female rats bearing DMBA-induced tumors, specific uterine and tumor uptakes were observed, although at 30 min the tumor uptake was only 23 to 30% of the uptake in the uterus. Tritiated 17..cap alpha..-methylestradiol with a specific activity of 6 Ci/mmole showed a similar tissue distribution. Our results indicate that a 17 ..cap alpha..-methylestradiol is promising as an estrogen-receptor-binding radiopharmaceutical.

  11. Primer extension studies on alpha-amylase mRNAs in barley aleurone. II. Hormonal regulation of expression.

    Science.gov (United States)

    Chandler, P M; Jacobsen, J V

    1991-04-01

    Relative levels of different alpha-amylase mRNAs were assessed by primer extension experiments using RNA prepared from aleurone of barley (Hordeum vulgare L. cv. Himalaya). Three different aleurone systems were studied: protoplasts prepared from aleurone layers, isolated aleurone layers, and aleurone from germinated grain. Oligonucleotide primers specific for the low-pI and high-pI alpha-amylase groups allowed the levels of different alpha-amylase mRNAs to be assessed both within and between the two groups. In all aleurone systems the same set of alpha-amylase mRNAs was produced in response to either applied gibberellic acid (aleurone protoplasts, isolated aleurone layers) or, presumably, native gibberellin(s) (germinated grain). This result indicates that the same set of genes is being expressed in each case. Differences were observed between the different aleurone systems in regulation of levels of alpha-amylase mRNAs. In particular, the regulation of alpha-amylase mRNA levels in aleurone of germinated grain has unique features which are not adequately explained by the response of isolated aleurone layers to gibberellic acid.

  12. Problems connected with the use of oligonucleotide probes with a high degree of degeneracy. Identification of mRNA and of cDNA clones corresponding to the gene of the. cap alpha. -subunit of Na/sup +/, K/sup +/-ATPase

    Energy Technology Data Exchange (ETDEWEB)

    Petrukhin, K.E.; Grishin, A.V.; Arsenyan, S.G.; Broude, N.E.; Grinkevich, V.A.; Filippova, L.Yu.; Severtsova, I.V.; Modyanov, N.N.

    1986-10-01

    To identify and search for nucleotide sequences containing the structural part of the gene of the ..cap alpha..-subunit of Na/sup +/, K/sup +/-ATPase, 17-membered oligonucleotide probes corresponding to the peptide Lys-Asp-Ala-Phe-Gln-Asn have been synthesized. It has been shown that, with a 64-fold degeneracyd, the 17-membered probe is suitable only for the identification of a specific sequence in mRNA. To search for clones containing cDNA fragments, preliminary fractionation of the probes with the aid of HPLC or the resynthesis of groups of oligonucleotides with a lower degeneracy is necessary.

  13. Role of the Rubisco Small Subunit

    Energy Technology Data Exchange (ETDEWEB)

    Spreitzer, Robert Joseph [Univ. of Nebraska, Lincoln, NE (United States)

    2016-11-05

    possible structural pathway between the small-subunit βA-βB loop and alpha-helix 8 of the large-subunit α/β-barrel active site. Hybrid enzymes were also created comprised of plant small subunits and Chlamydomonas large subunits, and these enzymes have increases in CO2/O2 specificity, further indicating that small subunits may be the key for ultimately engineering an improved Rubisco enzyme.

  14. MOLECULAR ANALYSIS OF THE TOPOISOMERASE-II ALPHA-GENE AND ITS EXPRESSION IN HUMAN OVARIAN-CANCER

    NARCIS (Netherlands)

    VANDERZEE, AGJ; DEVRIES, EGE; HOLLEMA, H; KAYE, SB; BROWN, R; KEITH, WN

    Background: DNA topoisomerase II enzymes are key targets for the group of anti-tumour agents known as topoisomerase inhibitors. In general, cell lines which express high levels of topoisomerase II are sensitive to the cytotoxic effects of the topoisomerase poisons. The levels of topoisomerase II

  15. $\\alpha_s$ review (2016)

    CERN Document Server

    d'Enterria, David

    2016-01-01

    The current world-average of the strong coupling at the Z pole mass, $\\alpha_s(m^2_{Z}) = 0.1181 \\pm 0.0013$, is obtained from a comparison of perturbative QCD calculations computed, at least, at next-to-next-to-leading-order accuracy, to a set of 6 groups of experimental observables: (i) lattice QCD "data", (ii) $\\tau$ hadronic decays, (iii) proton structure functions, (iv) event shapes and jet rates in $e^+e^-$ collisions, (v) Z boson hadronic decays, and (vi) top-quark cross sections in p-p collisions. In addition, at least 8 other $\\alpha_s$ extractions, usually with a lower level of theoretical and/or experimental precision today, have been proposed: pion, $\\Upsilon$, W hadronic decays; soft and hard fragmentation functions; jets cross sections in pp, e-p and $\\gamma$-p collisions; and photon F$_2$ structure function in $\\gamma\\,\\gamma$ collisions. These 14 $\\alpha_s$ determinations are reviewed, and the perspectives of reduction of their present uncertainties are discussed.

  16. The Building the Bridge survey for z=3 Ly-alpha emitting galaxies II: Completion of the survey

    CERN Document Server

    Grove, L F; Ledoux, C; Limousin, M; Møller, P; Nilsson, K; Thomsen, B

    2009-01-01

    (Abridged). We aim at bridging the gap between absorption selected and emission selected galaxies at z~3 by probing the faint end of the luminosity function of star-forming galaxies at z~3. We have performed narrow-band imaging in three fields with intervening QSO absorbers (a damped Ly$\\alpha$ absorber and two Lyman-limit systems) using the VLT. We target Ly-alpha at redshifts 2.85, 3.15 and 3.20. We find a consistent surface density of about 10 Ly-alpha-emitters per square arcmin per unit redshift in all three fields down to our detection limit of about 3x10^41 ergs s^-1. The luminosity function is consistent with what has been found by other surveys at similar redshifts. About 85% of the sources are fainter than the canonical limit of R=25.5 for most Lyman-break galaxy surveys. In none of the three fields do we detect the emission counterparts of the QSO absorbers. In particular we do not detect the counterpart of the z=2.85 damped Ly-alpha absorber towards Q2138-4427. Narrow-band surveys for Ly-alpha emit...

  17. LT-IIb(T13I, a non-toxic type II heat-labile enterotoxin, augments the capacity of a ricin toxin subunit vaccine to evoke neutralizing antibodies and protective immunity.

    Directory of Open Access Journals (Sweden)

    Christopher J Greene

    Full Text Available Currently, there is a shortage of adjuvants that can be employed with protein subunit vaccines to enhance protection against biological threats. LT-IIb(T13I is an engineered nontoxic derivative of LT-IIb, a member of the type II subfamily of heat labile enterotoxins expressed by Escherichia coli, that possesses potent mucosal adjuvant properties. In this study we evaluated the capacity of LT-IIb(T13I to augment the potency of RiVax, a recombinant ricin toxin A subunit vaccine, when co-administered to mice via the intradermal (i.d. and intranasal (i.n. routes. We report that co-administration of RiVax with LT-IIb(T13I by the i.d. route enhanced the levels of RiVax-specific serum IgG antibodies (Ab and elevated the ratio of ricin-neutralizing to non-neutralizing Ab, as compared to RiVax alone. Protection against a lethal ricin challenge was also augmented by LT-IIb(T13I. While local inflammatory responses elicited by LT-IIb(T13I were comparable to those elicited by aluminum salts (Imject®, LT-IIb(T13I was more effective than aluminum salts at augmenting production of RiVax-specific serum IgG. Finally, i.n. administration of RiVax with LT-IIb(T13I also increased levels of RiVax-specific serum and mucosal Ab and enhanced protection against ricin challenge. Collectively, these data highlight the potential of LT-IIb(T13I as an effective next-generation i.d., or possibly i.n. adjuvant for enhancing the immunogenicity of subunit vaccines for biodefense.

  18. Calpain- and caspase-mediated alphaII-spectrin and tau proteolysis in rat cerebrocortical neuronal cultures after ecstasy or methamphetamine exposure.

    Science.gov (United States)

    Warren, Matthew W; Zheng, Wenrong; Kobeissy, Firas H; Cheng Liu, Ming; Hayes, Ronald L; Gold, Mark S; Larner, Stephen F; Wang, Kevin K W

    2007-08-01

    Abuse of 3,4-methylenedioxymethamphetamine (MDMA or Ecstasy) and methamphetamine (Meth or Speed) is a growing international problem with an estimated 250 million users of psychoactive drugs worldwide. It is important to demonstrate and understand the mechanism of neurotoxicity so potential prevention and treatment therapies can be designed. In this study rat primary cerebrocortical neuron cultures were challenged with MDMA and Meth (1 or 2 mM) for 24 and 48 h and compared to the excitotoxin N-methyl-D-aspartate (NMDA). The neurotoxicity of these drugs, as assessed by microscopy, lactate dehydrogenase release and immunoblot, was shown to be both dose- and time-dependent. Immunoblot analysis using biomarkers of cell death showed significant proteolysis of both alphaII-spectrin and tau proteins. Breakdown products of alphaII-spectrin (SBDPs) of 150, 145, and 120 kDa and tau breakdown products (TBDPs) of 45, 32, 26, and 14 kDa were observed. The use of the protease inhibitors calpain inhibitor SJA6017 and caspase inhibitors z-VAD-fmk and Z-D-DCB, attenuated drug-induced alphaII-spectrin and tau proteolysis. The calpain inhibitor reduced the calpain-induced breakdown products SBDP145 and TBDP14, but there was an offset increase in the caspase-mediated breakdown products SBDP120 and TBDP45. The caspase inhibitors, on the other hand, decreased SBDP120 and TBDP45. These data suggest that both MDMA and Meth trigger concerted proteolytic attacks of the structural proteins by both calpain and caspase family of proteases. The ability of the protease inhibitors to reduce the damage caused by these drugs suggests that the treatment arsenal could include similar drugs as possible tools to combat the drug-induced neurotoxicity in vivo.

  19. Ligand- and subunit-specific conformational changes in the ligand-binding domain and the TM2-TM3 linker of {alpha}1 {beta}2 {gamma}2 GABAA receptors

    DEFF Research Database (Denmark)

    Wang, Qian; Pless, Stephan Alexander; Lynch, Joseph W

    2010-01-01

    changes are essential for gating. Here we used voltage clamp fluorometry to investigate the roles of loops C and F in gating the α1 β2 γ2 GABA(A) receptor. Voltage clamp fluorometry involves labeling introduced cysteines with environmentally sensitive fluorophores and inferring structural rearrangements......Cys-loop receptor ligand binding sites are located at subunit interfaces where they are lined by loops A-C from one subunit and loops D-F from the adjacent subunit. Agonist binding induces large conformational changes in loops C and F. However, it is controversial as to whether these conformational...... from ligand-induced fluorescence changes. Previous attempts to define the roles of loops C and F using this technique have focused on homomeric Cys-loop receptors. However, the problem with studying homomeric receptors is that it is difficult to eliminate the possibility of bound ligands interacting...

  20. Study of the terahertz spectra of crystalline materials using NDDO semi-empirical methods: polyethylene, poly(vinylidene fluoride) form II and $\\alpha$-D-glucose

    CERN Document Server

    Chamorro-Posada, P

    2016-01-01

    Semi-empirical quantum chemistry methods offer a very interesting compromise between accuracy and computational load. In order to assess the performance of NDDO methods in the interpretation of terahertz spectra, the low frequency vibration modes of three crystalline materials, namely, polyethylene, poly(vinylidene fluoride) form II and $\\alpha$-D-glucose have been studied using the PM6 and PM7 Hamiltonians and the results have been compared with the experimental data and former calculations. The results show good qualitative or semi-quantitative agreement with the experimentally observed terahertz spectra.

  1. Prolonged Survival in a Case of Chemotherapy-Sensitive Gastric Cancer That Produced Alpha-Fetoprotein and Protein Induced by Vitamin K Antagonist-II

    Directory of Open Access Journals (Sweden)

    Naotaka Ogasawara

    2015-04-01

    Full Text Available The number of reported cases of alpha-fetoprotein (AFP-producing gastric cancer has gradually increased, with a reported prevalence of 1.3-1.5% of all gastric cancer cases. However, reports of gastric cancer accompanied by elevated serum levels of both AFP and protein induced by vitamin K antagonist-II (PIVKA-II are rare. The prognosis of AFP- and PIVKA-II-producing gastric cancer has been reported to be very poor because the tumor cells were considered to have a high malignant potential and the cancer progressed rapidly. We described a case of gastric cancer producing AFP and PIVKA-II in which chemotherapy was effective and resulted in prolonged survival, and these two tumor markers were useful for monitoring the treatment response. Routine health screening using upper abdominal ultrasonography revealed hepatic tumors in an apparently healthy 65-year-old man. Whole-body computed tomography (CT revealed multiple hepatic tumors, and an esophagogastroduodenoscopy (EGD revealed a Bormann type 3 tumor in the lower stomach. A biopsy specimen confirmed that the tumor was immunohistochemically positive for AFP, PIVKA-II, and human epidermal growth factor receptor 2. After chemotherapy, the gastric tumor appeared as a small elevated lesion on EGD, and CT revealed a remarkable reduction in the size of the metastatic liver tumors. The patient is still alive, 35 months after the initial chemotherapy.

  2. Syntheses and characterization of two novel 1D Pb(II) Halide supramolecular polymers possessing incomplete Cubane subunit directed by -conjugated Dication templates

    Indian Academy of Sciences (India)

    Chengjie Ma; Mei Liu; Wenli Zhang; Haijuan Du; Yao Li; Chaohai Wang; Yunyin Niu

    2015-07-01

    Two novel cation-templated complexes, {(1, 4-PMBP)[Pb4I10]·DMF} n(1) {(DBBP)2[Pb5I8Br6]} n(2), (1,4-PMBP·2Br =1,1”-[1,4-phenylene-bis(methylene)]bis-4,4’-bipyridinium dibromide; DBBP·2Br = N, N’-dibenzyl- 4, 4’-bipyridinium dibromide) have been synthesized via the self-assembly reaction in solution. X-ray crystallography showed that compounds 1 and 2 can be regarded as 1D iodoplumbate examples which contain incomplete cubane subunit directed by -conjugated dication templates. It is the H-bonds and electrostatic interactions between the organic counter cations and inorganic moieties that contribute the crystal packing. These compounds have been further characterized by IR spectroscopy, UV-Vis spectra, elemental analysis and thermostability properties.

  3. Evasion of the innate immune response: the Old World alphavirus nsP2 protein induces rapid degradation of Rpb1, a catalytic subunit of RNA polymerase II.

    Science.gov (United States)

    Akhrymuk, Ivan; Kulemzin, Sergey V; Frolova, Elena I

    2012-07-01

    The Old World alphaviruses are emerging human pathogens with an ability to cause widespread epidemics. The latest epidemic of Chikungunya virus, from 2005 to 2007, affected over 40 countries in Africa, Asia, and Europe. The Old World alphaviruses are highly cytopathic and known to evade the cellular antiviral response by inducing global inhibition of transcription in vertebrate cells. This function was shown to be mediated by their nonstructural nsP2 protein; however, the detailed mechanism of this phenomenon has remained unknown. Here, we report that nsP2 proteins of Sindbis, Semliki Forest, and Chikungunya viruses inhibit cellular transcription by inducing rapid degradation of Rpb1, a catalytic subunit of the RNAPII complex. This degradation of Rpb1 is independent of the nsP2-associated protease activity, but, instead, it proceeds through nsP2-mediated Rpb1 ubiquitination. This function of nsP2 depends on the integrity of the helicase and S-adenosylmethionine (SAM)-dependent methyltransferase-like domains, and point mutations in either of these domains abolish Rpb1 degradation. We go on to show that complete degradation of Rpb1 in alphavirus-infected cells occurs within 6 h postinfection, before other previously described virus-induced changes in cell physiology, such as apoptosis, autophagy, and inhibition of STAT1 phosphorylation, are detected. Since Rpb1 is a subunit that catalyzes the polymerase reaction during RNA transcription, degradation of Rpb1 plays an indispensable role in blocking the activation of cellular genes and downregulating cellular antiviral response. This indicates that the nsP2-induced degradation of Rpb1 is a critical mechanism utilized by the Old World alphaviruses to subvert the cellular antiviral response.

  4. Biogenesis of lysosomal enzymes in the alpha-glucosidase II-deficient modA mutant of Dictyostelium discoideum: retention of alpha-1,3-linked glucose on N-linked oligosaccharides delays intracellular transport but does not alter sorting of alpha-mannosidase or beta-glucosidase.

    Science.gov (United States)

    Ebert, D L; Bush, J M; Dimond, R L; Cardelli, J A

    1989-09-01

    The endoplasmic reticulum-localized enzyme alpha-glucosidase II is responsible for removing the two alpha-1,3-linked glucose residues from N-linked oligosaccharides of glycoproteins. This activity is missing in the modA mutant strain, M31, of Dictyostelium discoideum. Results from both radiolabeled pulse-chase and subcellular fractionation experiments indicate that this deficiency did not prevent intracellular transport and proteolytic processing of the lysosomal enzymes, alpha-mannosidase and beta-glucosidase. However, the rate at which the glucosylated precursors left the rough endoplasmic reticulum was several-fold slower than the rate at which the wild-type precursors left this compartment. Retention of glucose residues did not disrupt the binding of the precursor forms of the enzymes with intracellular membranes, indicating that the delay in movement of proteins from the ER did not result from lack of association with membranes. However, the mutant alpha-mannosidase precursor contained more trypsin-sensitive sites than did the wild-type precursor, suggesting that improper folding of precursor molecules might account for the slow rate of transport to the Golgi complex. Percoll density gradient fractionation of extracts prepared from M31 cells indicated that the proteolytically processed mature forms of alpha-mannosidase and beta-glucosidase were localized to lysosomes. Finally, the mutation in M31 may have other, more dramatic, effects on the lysosomal system since two enzymes, N-acetylglucosaminidase and acid phosphatase, were secreted much less efficiently from lysosomal compartments by the mutant strain.

  5. MgII Absorption Lines in z=2.974 Damped Lyman-alpha System toward Gravitationally Lensed QSO APM 08279+5255 Detection of Small-scale Structure in MgII Absorbing Clouds

    CERN Document Server

    Kobayashi, N; Goto, M; Tokunaga, A; Kobayashi, Naoto; Terada, Hiroshi; Goto, Miwa; Tokunaga, Alan

    2002-01-01

    1.02-1.16 micron spectra (R ~ 7,000) of the gravitationally lensed QSO APM 08279+5255 at z_em=3.911 were obtained during the commissioning run of IRCS, the 1-5 micron near-infrared camera and spectrograph for the Subaru 8.2 m Telescope. Strong MgII doublet at 2976,2800 angstrom and FeII (2600 angstrom), FeII (2587 angstrom) absorption lines at z_abs=2.974 were clearly detected in the rest-frame UV spectra, confirming the presence of a damped Lyman-alpha system at the redshift as suggested by Petitjean et al. Also MgI (2853 angstrom) absorption line is probably detected. An analysis of the absorption lines including velocity decomposition was performed. This is a first detailed study of MgII absorption system at high redshift (z > 2.5) where the MgII doublet shifts into the near-infrared in the observer's frame. The spectra of the lensed QSO pair A and B with 0.38 arcsec separation were resolved in some exposure frames under excellent seeing condition. We extracted the MgII doublet spectra of A and B separatel...

  6. Mutation of Gly195 of the ChlH Subunit of Mg-chelatase Reduces Chlorophyll and Further Disrupts PS II Assembly in a Ycf48-Deficient Strain of Synechocystis sp. PCC 6803

    Science.gov (United States)

    Crawford, Tim S.; Eaton-Rye, Julian J.; Summerfield, Tina C.

    2016-01-01

    Biogenesis of the photosystems in oxygenic phototrophs requires co-translational insertion of chlorophyll a. The first committed step of chlorophyll a biosynthesis is the insertion of a Mg2+ ion into the tetrapyrrole intermediate protoporphyrin IX, catalyzed by Mg-chelatase. We have identified a Synechocystis sp. PCC 6803 strain with a spontaneous mutation in chlH that results in a Gly195 to Glu substitution in a conserved region of the catalytic subunit of Mg-chelatase. Mutant strains containing the ChlH Gly195 to Glu mutation were generated using a two-step protocol that introduced the chlH gene into a putative neutral site in the chromosome prior to deletion of the native gene. The Gly195 to Glu mutation resulted in strains with decreased chlorophyll a. Deletion of the PS II assembly factor Ycf48 in a strain carrying the ChlH Gly195 to Glu mutation did not grow photoautotrophically. In addition, the ChlH-G195E:ΔYcf48 strain showed impaired PS II activity and decreased assembly of PS II centers in comparison to a ΔYcf48 strain. We suggest decreased chlorophyll in the ChlH-G195E mutant provides a background to screen for the role of assembly factors that are not essential under optimal growth conditions. PMID:27489555

  7. A murine experimental anthracycline extravasation model: pathology and study of the involvement of topoisomerase II alpha and iron in the mechanism of tissue damage

    DEFF Research Database (Denmark)

    2010-01-01

    The bisdioxopiperazine topoisomerase II catalytic inhibitor dexrazoxane has successfully been introduced into the clinic as an antidote to accidental anthracycline extravasation based on our preclinical mouse studies. The histology of this mouse extravasation model was investigated and found...... with dense dermal connective tissue. The extension of this fibrosis was quantified, and dexrazoxane intervention resulted in a statistically significant decrease in fibrosis extension, as also observed in the clinic. Several mechanisms have been proposed in anthracycline extravasation cytotoxicity, and we...... tested two major hypotheses: (1) interaction with topoisomerase II alpha and (2) the formation of tissue damaging reactive oxygen species following redox cycling of an anthracycline Fe(2+) complex. Dexrazoxane could minimise skin damage via both mechanisms, as it stops the catalytic activity...

  8. Early expression of GABA(A) receptor delta subunit in the neonatal rat hippocampus.

    Science.gov (United States)

    Didelon, F; Mladinic', M; Cherubini, E; Bradbury, A

    2000-12-01

    The cDNA library screening strategy was used to identify the genes encoding for GABA(A) receptor subunits in the rat hippocampus during development. With this technique, genes encoding eleven GABA(A) receptor subunits were identified. The alpha5 subunit was by far the most highly expressed, followed by the gamma2, alpha2 and alpha4 subunits respectively. The expression of the beta2, alpha1, gamma1, beta1 and beta3 subunits was moderate, although that of the alpha3 and delta subunits was weak. In situ hybridization experiments, using digoxigenin-labeled cRNA probes, confirmed that the delta subunit was expressed in the neonatal as well as in the adult hippocampus, and is likely to form functional receptors in association with other subunits of the GABA(A) receptor. When the more sensitive RT-PCR approach was used, the gamma3 subunit was also detected, suggesting that this subunit is present in the hippocampus during development but at low levels of expression. The insertion of the delta subunit into functional GABA(A) receptors may enhance the efficacy of GABA in the immediate postnatal period when this amino acid is still exerting a depolarizing and excitatory action.

  9. Maltose effects on barley malt diastatic power enzyme activity and thermostability at high isothermal mashing temperature: II. Alpha-amylase

    Science.gov (United States)

    Maltose, the primary product of starch degradation during mashing, has the potential as a compatible solute to affect the activity of and increase the thermostability of barley malt alpha-amylase activity at high temperatures used in mashing and temperatures above those normally used in mashing. To ...

  10. Deep HeII and CIV Spectroscopy of a Giant Lyman alpha Nebula: Dense Compact Gas Clumps in the Circumgalactic Medium of a z~2 Quasar

    CERN Document Server

    Battaia, Fabrizio Arrigoni; Prochaska, J Xavier; Cantalupo, Sebastiano

    2015-01-01

    The recent discovery by Cantalupo et al. (2014) of the largest (~500 kpc) and luminous Ly-alpha nebula associated with the quasar UM287 (z=2.279) poses a great challenge to our current understanding of the astrophysics of the halos hosting massive z~2 galaxies. Either an enormous reservoir of cool gas is required $M\\simeq10^{12}$ $M_{\\odot}$, exceeding the expected baryonic mass available, or one must invoke extreme gas clumping factors not present in high-resolution cosmological simulations. However, observations of Ly-alpha emission alone cannot distinguish between these two scenarios. We have obtained the deepest ever spectroscopic integrations in the HeII and CIV lines with the goal of detecting extended line emission, but detect neither line to a 3$\\sigma$ limiting SB $\\simeq10^{-18}$ erg/s/cm$^2$/arcsec$^2$. We construct models of the expected emission spectrum in the highly probable scenario that the nebula is powered by photoionization from the central hyper-luminous quasar. The non-detection of HeII ...

  11. Phosphorylation of the PCNA binding domain of the large subunit of replication factor C by Ca2+/calmodulin-dependent protein kinase II inhibits DNA synthesis

    DEFF Research Database (Denmark)

    Maga, G; Mossi, R; Fischer, R

    1997-01-01

    that the PCNA binding domain is phosphorylated by the Ca2+/calmodulin-dependent protein kinase II (CaMKII), an enzyme required for cell cycle progression in eukaryotic cells. The DNA binding domain, on the other hand, is not phosphorylated. Phosphorylation by CaMKII reduces the binding of PCNA to RF...

  12. Coupling of metal-based light-harvesting antennas and electron-donor subunits: Trinuclear Ruthenium(II) complexes containing tetrathiafulvalene-substituted polypyridine ligands

    DEFF Research Database (Denmark)

    Campagna, Sebastiano; Serroni, Scolastica; Puntoriero, Fausto

    2002-01-01

    Three new tetrathiafulvalene-substituted 2,2'-bipyridine ligands, cis-bpy-TTF1, trans-bpy-TTF1, and cis-bpy-TTF2 have been prepared and characterized. X-ray analysis of trans-bpy-TTF1, is also reported. Such ligands have been used to prepare two new trinuclear Ru-II complexes, namely, [{(bpy)(2)R...

  13. Molecular investigations of BK(Ca) channels and the modulatory beta-subunits in porcine basilar and middle cerebral arteries

    DEFF Research Database (Denmark)

    Johansson, Helle Wulf; Hay-Schmidt, Anders; Poulsen, Asser Nyander

    2009-01-01

    arteries using reverse transcription polymerase chain reaction (RT-PCR) and quantitative real-time PCR. Western blotting was used to detect immunoreactivity for the porcine BK(Ca) channel alpha-subunit and beta-subunit proteins. The BK(Ca) channel alpha-subunit RNA and protein distribution patterns were......-PCR in porcine basilar and middle cerebral arteries. However, at the protein level, only, the beta1-subunit protein was found by western blotting....

  14. An Observational Pursuit for Population III Stars in a Ly_alpha Emitter at z=6.33 through HeII Emission

    CERN Document Server

    Nagao, T; Maiolino, R; Marconi, A; Taniguchi, Y; Aoki, K; Ajiki, M; Shioya, Y; Nagao, Tohru; Motohara, Kentaro; Maiolino, Roberto; Marconi, Alessandro; Taniguchi, Yoshiaki; Aoki, Kentaro; Ajiki, Masaru; Shioya, Yasuhiro

    2005-01-01

    We present a very deep near-infrared spectroscopic observation of a strong Ly_alpha emitter at z=6.33, SDF J132440.6+273607, which we used to search for HeII 1640. This emission line is expected if the target hosts a significant number of population III stars. Even after 42 ksec of integration with the Subaru/OHS spectrograph, no emission-line features are detected in the JH band, which confirms that SDF J132440.6+273607 is neither an active galactic nucleus nor a low-$z$ emission-line object. We obtained a 2sigma upper-limit of 9.06e-18 ergs/s/cm^2 on the HeII 1640 emission line flux, which corresponds to a luminosity of 4.11e42 ergs/s. This upper-limit on the HeII 1640 luminosity implies that the upper limit on population III star-formation rate is in the range 4.9--41.2 M_sun/yr if population III stars suffer no mass loss, and in the range 1.8--13.2 M_sun/yr if strong mass loss is present. The non-detection of HeII in SDF J132440.6+273607 at z=6.33 may thus disfavor weak feedback models for population III ...

  15. Complementation of Escherichia coli unc mutant strains by chloroplast and cyanobacterial F1-ATPase subunits.

    Science.gov (United States)

    Lill, H; Burkovski, A; Altendorf, K; Junge, W; Engelbrecht, S

    1993-10-04

    The genes encoding the five subunits of the F1 portion of the ATPases from both spinach chloroplasts and the cyanobacterium Synechocystis sp. PCC 6803 were cloned into expression vectors and expressed in Escherichia coli. The recombinant subunits formed inclusion bodies within the cells. Each particular subunit was expressed in the respective unc mutant, each unable to grow on non-fermentable carbon sources. The following subunits restored growth under conditions of oxidative phosphorylation: alpha (both sources, cyanobacterial subunit more than spinach subunit), beta (cyanobacterial subunit only), delta (both spinach and Synechocystis), and epsilon (both sources), whereas no growth was achieved with the gamma subunits from both sources. Despite a high degree of sequence homology the large subunits alpha and beta of spinach and cyanobacterial F1 were not as effective in the substitution of their E. coli counterparts. On the other hand, the two smallest subunits of the E. coli ATPase could be more effectively replaced by their cyanobacterial or chloroplast counterparts, although the sequence identity or even similarity is very low. We attribute these findings to the different roles of these subunits in F1: The large alpha and beta subunits contribute to the catalytic centers of the enzyme, a function rendering them very sensitive to even minor changes. For the smaller delta and epsilon subunits it was sufficient to maintain a certain tertiary structure during evolution, with little emphasis on the conservation of particular amino acids.

  16. The MUSCLES Treasury Survey II: Intrinsic Lyman Alpha and Extreme Ultraviolet Spectra of K and M Dwarfs with Exoplanets

    CERN Document Server

    Youngblood, Allison; Loyd, R O Parke; Linsky, Jeffrey L; Redfield, Seth; Schneider, P Christian; Wood, Brian E; Brown, Alexander; Froning, Cynthia; Miguel, Yamila; Rugheimer, Sarah; Walkowicz, Lucianne

    2016-01-01

    The ultraviolet (UV) spectral energy distributions of low-mass (K- and M-type) stars play a critical role in the heating and chemistry of exoplanet atmospheres, but are not observationally well-constrained. Direct observations of the intrinsic flux of the Lyman alpha line (the dominant source of UV photons from low-mass stars) are challenging, as interstellar HI absorbs the entire line core for even the closest stars. To address the existing gap in empirical constraints on the UV flux of K and M dwarfs, the MUSCLES HST Treasury Survey has obtained UV observations of 11 nearby M and K dwarfs hosting exoplanets. This paper presents the Lyman alpha and extreme-UV spectral reconstructions for the MUSCLES targets. Most targets are optically inactive, but all exhibit significant UV activity. We use a Markov Chain Monte Carlo technique to correct the observed Lyman alpha profiles for interstellar absorption, and we employ empirical relations to compute the extreme-UV spectral energy distribution from the intrinsic L...

  17. Alpha1 and Alpha2 Integrins Mediate Invasive Activity of Mouse Mammary Carcinoma Cells through Regulation of Stromelysin-1 Expression

    Energy Technology Data Exchange (ETDEWEB)

    Lochter, Andre; Navre, Marc; Werb, Zena; Bissell, Mina J

    1998-06-29

    Tumor cell invasion relies on cell migration and extracellular matrix proteolysis. We investigated the contribution of different integrins to the invasive activity of mouse mammary carcinoma cells. Antibodies against integrin subunits {alpha}6 and {beta}1, but not against {alpha}1 and {alpha}2, inhibited cell locomotion on a reconstituted basement membrane in two-dimensional cell migration assays, whereas antibodies against {beta}1, but not against a6 or {alpha}2, interfered with cell adhesion to basement membrane constituents. Blocking antibodies against {alpha}1 integrins impaired only cell adhesion to type IV collagen. Antibodies against {alpha}1, {alpha}2, {alpha}6, and {beta}1, but not {alpha}5, integrin subunits reduced invasion of a reconstituted basement membrane. Integrins {alpha}1 and {alpha}2, which contributed only marginally to motility and adhesion, regulated proteinase production. Antibodies against {alpha}1 and {alpha}2, but not {alpha}6 and {beta}1, integrin subunits inhibited both transcription and protein expression of the matrix metalloproteinase stromelysin-1. Inhibition of tumor cell invasion by antibodies against {alpha}1 and {alpha}2 was reversed by addition of recombinant stromelysin-1. In contrast, stromelysin-1 could not rescue invasion inhibited by anti-{alpha}6 antibodies. Our data indicate that {alpha}1 and {alpha}2 integrins confer invasive behavior by regulating stromelysin-1 expression, whereas {alpha}6 integrins regulate cell motility. These results provide new insights into the specific functions of integrins during tumor cell invasion.

  18. A comparison of intraspecific patterns of DNA sequence variation in mitochondrial DNA, alpha-enolase, and MHC class II B loci in auklets (Charadriiformes: Alcidae).

    Science.gov (United States)

    Walsh, Hollie E; Friesen, Vicki L

    2003-12-01

    Patterns of DNA sequence variation can be used to learn about mechanisms of organismal evolution, but only if mechanisms of sequence evolution are well understood. Although theories of molecular evolution are well developed, few empirical studies have addressed patterns and mechanisms of sequence evolution in nuclear genes within species. In the present study, we compared DNA sequences among three loci with different evolutionary constraints to determine the influences of effective population size, balancing selection, and linkage on intraspecific patterns of sequence variation. Specifically, we assessed the degree and nature of polymorphism in a 307-base pair (bp) fragment of the mitochondrial cytochrome b gene, intron VIII of the gene for alpha-enolase (a presumably neutral nuclear gene), and an approximately 600-bp fragment of an MHC class II B gene, including 155 bp of the hypervariable peptide binding region (a nuclear locus thought to be under balancing selection) for least and crested auklets (Aethia pusilla and A. cristatella; Charadriiformes: Alcidae). Transspecies polymorphism was found in both alpha-enolase and the MHC but not cytochrome b and, given estimates of effective population size, probably represents retained ancestral variation. Biases in nucleotide composition suggested that mutational bias, tRNA availability, and the secondary structure of mRNA and/or DNA may influence base usage. Several lines of evidence indicated that balancing selection may be acting on the MHC II B exon 2. However, no evidence of balancing selection was observed in the intron and exon sequences immediately downstream of MHC II B exon 2.

  19. Comparing prothrombin induced by vitamin K absence-II (PIVKA-II) with the oncofetal proteins glypican-3, Alpha feto protein and carcinoembryonic antigen in diagnosing hepatocellular carcinoma among Egyptian patients.

    Science.gov (United States)

    Abd El Gawad, Iman A; Mossallam, Ghada I; Radwan, Noha H; Elzawahry, Heba M; Elhifnawy, Niveen M

    2014-06-01

    Hepatocellular carcinoma (HCC) is usually asymptomatic in the early stage and does not show elevated alpha-feto protein (AFP). AFP shows 60-80% sensitivity in diagnosing HCC. Glypican3 (GPC-3) is an oncofetal protein that is only detected in HCC cells but not in benign liver tissues, while Carcinoembryonic antigen (CEA) is expressed in various neoplasms including HCC. Although, it is not specific for HCC. Prothrombin induced by vitamin K absence-II (PIVKA-II) is an abnormal prothrombin protein that is increased in the serum of HCC patients. It has higher sensitivity and specificity compared to AFP. The aim of this study is to compare the clinical utility of PIVKA-II with GPC-3, AFP and CEA in diagnosing HCC. This study included 40 patients with HCC, 10 patients with cirrhosis as a benign control group, and 10 apparently healthy volunteers as normal controls. Serum samples were subjected to routine laboratory investigations, measurement of CEA, AFP using MEIA technique (Axsym), glypican3, and PIVKA-II using ELISA technique in the sera of all patients and controls. All markers showed the highest results in the HCC group. Higher concentrations of PIVKA-II were detected in patients with splenomegaly, and in tumors with size (>3cm). Combination of Glypican-3 and PIVKA-II showed the highest sensitivity, while GPC-3 alone and combination of GPC-3 and AFP showed the highest specificity to differentiate HCC from liver cirrhosis and normal controls. GPC-3, PIVKAII, and combination of both showed the highest sensitivity, while GPC-3 alone showed the highest specificity to differentiate HCC from liver cirrhosis. Glypican-3 is the only oncofetal antigen that showed comparable high diagnostic accuracy as PIVKA-II in diagnosing HCC among Egyptian patients. Copyright © 2014. Production and hosting by Elsevier B.V.

  20. Conserved sequence motifs in the small subunit of human general transcription factor TFIIE.

    Science.gov (United States)

    Sumimoto, H; Ohkuma, Y; Sinn, E; Kato, H; Shimasaki, S; Horikoshi, M; Roeder, R G

    1991-12-05

    A general initiation factor, TFIIE, is essential for transcription initiation by RNA polymerase II in conjunction with other general factors. TFIIE is a heterotetramer containing two subunits of relative molecular mass 57,000 (TFIIE-alpha) and two of 34,000 (TFIIE-beta). TFIIE-beta is required in conjunction with TFIIE-alpha for transcription initiation. Here we report the cloning and expression of a complementary DNA encoding a functional human TFIIE-beta. Recombinant TFIIE-beta could replace the natural TFIIE-beta for transcription in conjunction with TFIIE-alpha. Amino-acid sequence comparisons reveal regions with sequence similarities to: subregion 3 of bacterial sigma factors; a region of RAP30 (the small subunit of TFIIF) with sequence similarity to a sigma-factor subregion implicated in binding to RNA polymerase; and a portion of the basic region-helix-loop-helix motif found in several enhancer-binding proteins. These potential homologies have implications for the role of TFIIE in preinitiation complex assembly and function.

  1. Studies of ternary surface complexes at liquid-solid interfaces in seawater. 3: Comparative studies of the E(%)-pH curves and the diffuse reflectance IR spectra of the {alpha}-FeOOH-Cu(II)-tryptophan system

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Zhengbin; Wang Wei; Liu Liansheng; Fu Youjun; Wu Zhijian [Ocean Univ. of Qingdao (China). Inst. of Marine Chemistry

    1997-06-01

    The E(%)-pH curves of the ternary surface complexes at liquid-solid interfaces in the simulated seawater system of {alpha}-FeOOH-Cu(II)-tryptophan were determined. The diffuse reflectance IR spectra of the species at the solid surfaces in the above ternary equilibration system were examined. The above two results were comparatively studied. It is shown that the coadsorption of Cu(II) and tryptophan on {alpha}0FeOOH surface results in the formation of the ternary surface complex. Cu(II) can promote the exchange adsorption of tryptophan on {alpha}-FeOOH surface. The diffuse reflectance IR spectra can give one some evidence for the structure of the ternary surface complex, and these results are in accordance with the results of the E(%)-pH curves.

  2. Inhibition of voltage-gated calcium channels by sequestration of beta subunits.

    Science.gov (United States)

    Cuchillo-Ibañez, Inmaculada; Aldea, Marcos; Brocard, Jacques; Albillos, Almudena; Weiss, Norbert; Garcia, Antonio G; De Waard, Michel

    2003-11-28

    The auxiliary Ca(v)beta subunit is essential for functional expression of high-voltage activated Ca(2+) channels. Here, we describe a lure sequence designed to sequester the Ca(v)beta subunits in transfected bovine chromaffin cells. This sequence is composed of the extracellular and transmembrane domains of the alpha chain of the human CD8, the I-II loop of Ca(v)2.1 subunit, and EGFP. We showed that expressing the CD8-I-II-EGFP sequence in chromaffin cells led to a >50% decrease in overall Ca(2+) current density. Although this decrease involved all the Ca(2+) channel types (L, N, P/Q, R), the proportion of each type supporting the remaining current was altered. A similar effect was observed after transfection when measuring the functional role of Ca(2+) channels in catecholamine release by chromaffin cells: global decrease of release and change of balance between the different channel types supporting it. Possible explanations for this apparent discrepancy are further discussed.

  3. A new h allele detected in Europe has a missense mutationin alpha(1,2)-fucosyltransferase motif II.

    Science.gov (United States)

    Wagner, T; Vadon, M; Staudacher, E; Schmarda, A; Gassner, C; Helmberg, W; Lanzer, G; Flegel, W A; Wagner, F F

    2001-01-01

    The FUT1 gene encodes an alpha(1,2)-fucosyltransferase (H transferase), which determines the blood group H. Nonfunctional alleles of this gene, called h alleles and carrying loss-of-function mutations, are observed in the exceedingly rare Bombay phenotype. Twenty-three distinct h alleles have been characterized at the molecular level in various populations. The FUT2 (SE) gene is highly homologous to FUT1 (H:). The FUT1 gene of an Austrian proband with the Bombay phenotype was characterized by nucleotide sequencing of the full-length coding sequence. A PCR method using sequence-specific primers for FUT2 genotyping in whites was developed. The plasma alpha(1,2)-fucosyltransferase activity was determined. The distribution of the mutations underlying 24 h alleles and 7 se alleles was analyzed. The proband carried a new h allele. Two nucleotide changes, G785A and C786A, in codon 262 of the FUT1 gene resulted in the replacement of serine by lysine. No alpha(1,2)-fucosyltransferase activity was detected in the proband's plasma. The proband was homozygous for the seG428A allele. Six of 17 missense mutations in nonfunctional h and se alleles occurred in highly conserved fucosyltransferase motifs. No loss-of-function mutation was observed in the aminoterminal section encompassing the transmembraneous helix. The missense mutation S262K in the FUT1 gene caused the loss of H transferase activity. The analysis of the distribution of mutations in nonfunctional FUT1 and FUT2 genes can point to functionally important domains in the H transferase.

  4. Purification and partial characterization of three forms of alpha-glucosidase from the fruit fly Drosophila melanogaster.

    Science.gov (United States)

    Tanimura, T; Kitamura, K; Fukuda, T; Kikuchi, T

    1979-01-01

    Three forms of alpha-glucosidase, I, II, and III, have been purified from the whole body extract of adult flies of Drosophila melanogaster in yields of 2.1, 5.3, and 6.7%, respectively. The purification procedures involved ammonium sulfate fractionation, Con A-Sepharose 4B affinity chromatography, DEAE-Sepharose CL-6B ion exchange chromatography, Sephacryl S-200 gel filtration, and preparative gel electrophoresis. Each purified enzyme showed a single band on polyacrylamide gel on both protein and enzyme activity staining. The molecular weights of alpha-glucosidases I, II, and III were estimated to be 200,000, 56,000, and 76,000, respectively, by gel filtration. SDS gels indicated that alpha-glucosidases II and III were each composed of a single polypeptide chain, whereas alpha-glucosidase I was composed of two identical subunits. Both alpha-glucosidases II and III hydrolyzed sucrose and p-nitrophenyl-alpha-D-glucoside (PNPG), but alpha-glucosidase I hydrolyzed PNPG to a much lesser extent than sucrose. For sucrose the pH optima of alpha-glucosidases I, II, and III were pH 6.0, 5.0, and 6.0 and the Km values were 13.1, 8.9, and 10 mM, respectively. For PNPG the pH optima of alpha-glucosidases II and III were pH 5.5 and 6.5 and the Km values were 0.77 and 0.21 mM, respectively.

  5. Alternative Splicing of Toll-Like Receptor 9 Transcript in Teleost Fish Grouper Is Regulated by NF-κB Signaling via Phosphorylation of the C-Terminal Domain of the RPB1 Subunit of RNA Polymerase II

    Science.gov (United States)

    Lee, Frank Fang-Yao; Hui, Cho-Fat; Chang, Tien-Hsien; Chiou, Pinwen Peter

    2016-01-01

    Similar to its mammalian counterparts, teleost Toll-like receptor 9 (TLR9) recognizes unmethylated CpG DNA presented in the genome of bacteria or DNA viruses and initiates signaling pathway(s) for immune responses. We have previously shown that the TLR9 pathway in grouper, an economically important teleost, can be debilitated by an inhibitory gTLR9B isoform, whose production is mediated by RNA alternative splicing. However, how does grouper TLR9 (gTLR9) signaling impinge on the RNA splicing machinery to produce gTlr9B is unknown. Here we show that the gTlr9 alternative splicing is regulated through ligand-induced phosphorylation of the C-terminal domain (CTD) of the largest subunit of RNA polymerase II (Pol II). We first observed that ligand-activated NF- κB pathway biased the production of the gTlr9B isoform. Because NF- κB is known to recruit p-TEFb kinase, which phosphorylates the Pol II CTD at Ser2 residues, we examined p-TEFb’s role in alternative splicing. We found that promoting p-TEFb kinase activity significantly favored the production of the gTlr9B isoform, whereas inhibiting p-TEFb yielded an opposite result. We further showed that p-TEFb-mediated production of the gTlr9B isoform down-regulates its own immune responses, suggesting a self-limiting mechanism. Taken together, our data indicate a feedback mechanism of the gTLR9 signaling pathway to regulate the alternative splicing machinery, which in turn produces an inhibitor to the pathway. PMID:27658294

  6. Heavily Reddened z~2 Type 1 Quasars II: H-alpha Star Formation Constraints from SINFONI IFU Observations

    CERN Document Server

    Alaghband-Zadeh, Susannah; Hewett, Paul C; McMahon, Richard G

    2016-01-01

    We use near infrared integral field unit (IFU) spectroscopy to search for H$\\alpha$ emission associated with star formation in a sample of 28 heavily reddened ($E(B-V)\\simeq$0.5-1.9), hyperluminous ($log(L_{bol}/ergs^{-1})\\simeq$47-48) broad-line quasars at $z\\simeq$1.4-2.7. Sixteen of the 28 quasars show evidence for star formation with an average extinction-corrected star formation rate (SFR) of 320$\\pm$70M$_\\odot$yr$^{-1}$. A stacked spectrum of the detections shows weak [NII], consistent with star formation as the origin of the narrow H$\\alpha$ emission. The star-forming regions are spatially unresolved in 11 of the 16 detections and constrained to lie within $\\sim$6kpc of the quasar emission. In the five resolved detections we find the star-forming regions are extended on scales of $\\sim$8kpc around the quasar emission. The prevalence of high SFRs is consistent with the identification of the heavily reddened quasar population as representing a transitional phase from apparent `starburst galaxies' to opti...

  7. ENDOPLASMIC RETICULUM-MEDIATED QUALITY-CONTROL OF TYPE-I COLLAGEN PRODUCTION BY CELLS FROM OSTEOGENESIS IMPERFECTA PATIENTS WITH MUTATIONS IN THE PRO-ALPHA-1(I) CHAIN CARBOXYL-TERMINAL PROPEPTIDE WHICH IMPAIR SUBUNIT ASSEMBLY

    NARCIS (Netherlands)

    LAMANDE, [No Value; CHESSLER, SD; GOLUB, SB; BYERS, PH; CHAN, D; COLE, WG; SILLENCE, DO; BATEMAN, JF

    1995-01-01

    A heterozygous single base change in exon 49 of COL1A1, which converted the codon for pro alpha 1(I) carboxyl-terminal propeptide residue 94 from tryptophan (TGG) to cysteine (TGT) was identified in a baby with lethal osteogenesis imperfecta (OI64). The C-propeptide mutations in OI64 and in another

  8. The scattering polarization of the Ly-alpha lines of H I and He II taking into account PRD and J-state interference effects

    CERN Document Server

    Belluzzi, Luca; Stepan, Jiri

    2012-01-01

    Recent theoretical investigations have pointed out that the cores of the Ly-alpha lines of H I and He II should show measurable scattering polarization signals when observing the solar disk, and that the magnetic sensitivity, through the Hanle effect, of such linear polarization signals is suitable for exploring the magnetism of the solar transition region. Such investigations were carried out in the limit of complete frequency redistribution (CRD) and neglecting quantum interference between the two upper J-levels of each line. Here we relax both approximations and show that the joint action of partial frequency redistribution (PRD) and J-state interference produces much more complex fractional linear polarization (Q/I) profiles, with large amplitudes in their wings. Such wing polarization signals turn out to be very sensitive to the temperature structure of the atmospheric model, so that they can be exploited for constraining the thermal properties of the solar chromosphere. Finally, we show that the approxi...

  9. Estrogen receptor-alpha gene PvuII (T/C) and XbaI (A/G) polymorphisms and endometriosis risk: a meta-analysis.

    Science.gov (United States)

    Li, Ya; Liu, Fei; Tan, Shi-Qiao; Wang, Yan; Li, Shang-Wei

    2012-10-15

    Estrogen receptor-alpha (ER-α) polymorphisms have been hypothesized to be associated with the risk of endometriosis (EMT) development by many epidemiological studies, however, the available results were conflicting. To derive a more precise estimation of association between the ER-α PvuII (T/C) and XbaI (A/G) polymorphisms and risk of EMT, we performed a meta-analysis. Summary odds ratios (ORs) and 95% confidence intervals (95% CIs) for ER-α polymorphisms and EMT were calculated in a fixed-effects model and a random-effects model when appropriate. This meta-analysis included 20 case-control studies with 1752 cases and 1742 controls for PvuII polymorphism and 15 case-control studies with 1349 cases and 1411 controls for XbaI polymorphism. For PvuII T/C polymorphism, no obvious associations were found for all genetic models when all studies were pooled into the meta-analysis. In the subgroup analyses by ethnicity, country, HWE in controls and study sample size, a significantly increased risk was observed among Caucasians (recessive model, OR=2.56, 95% CI=1.06-6.16) and among studies without the HWE (recessive model, OR=1.85, 95% CI=1.20-2.84). For XbaI A/G polymorphism, also no obvious associations were found for all genetic models. In the subgroup analyses by ethnicity, country, HWE in controls and study sample size, still no obvious associations were found. No publication bias was found in the present study. This meta-analysis suggests that ER-α gene PvuII (T/C) and XbaI (A/G) polymorphisms may not be associated with EMT risk, while the observed increase in risk of EMT may be due to small-study bias. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Structural regularities of helicoidally-like biopolymers in the framework of algebraic topology: II. {alpha}-Helix and DNA structures

    Energy Technology Data Exchange (ETDEWEB)

    Samoylovich, M. I., E-mail: samoylovich@technomash.ru [Central Research Technological Institute ' Technomash' (Russian Federation); Talis, A. L. [Russian Academy of Sciences, Nesmeyanov Institute of Organoelement Compounds (Russian Federation)

    2013-09-15

    The developed apparatus of the 'structural application' of algebraic geometry and topology makes it possible to determine topologically stable helicoidally-like packings of polyhedra (clusters). A packing found is limited by a minimal surface with zero instability index; this surface is set by the Weierstrass representation and corresponds to the bifurcation point. The symmetries of the packings under consideration are determined by four-dimensional polyhedra (polytopes) from a closed sequence, which begins with diamondlike polytope (240). One example of these packings is a packing of tetrahedra, which arises as a result of the multiplication of a peculiar starting aggregation of tetrahedra by a fractional 40/11 axis with an angle of helical rotation of 99 Degree-Sign . The arrangement of atoms in particular positions of this starting aggregation allows one to obtain a model of the {alpha}-helix. This apparatus makes it possible to determine a priori the symmetry parameters of DNA double helices.

  11. Directly imaging damped Ly-alpha galaxies at z>2. II: Imaging and spectroscopic observations of 32 quasar fields

    CERN Document Server

    Fumagalli, Michele; Prochaska, J Xavier; Kanekar, Nissim; Wolfe, Arthur M

    2014-01-01

    Damped Ly-alpha absorbers (DLAs) are a well-studied class of absorption line systems, and yet the properties of their host galaxies remain largely unknown. To investigate the origin of these systems, we have conducted an imaging survey of 32 quasar fields with intervening DLAs between z~1.9-3.8, leveraging a technique that allows us to image galaxies at any small angular separation from the background quasars. In this paper, we present the properties of the targeted DLA sample, new imaging observations of the quasar fields, and the analysis of new and archival spectra of the background quasars. In a companion paper we use these data to obtain an unbiased census of the DLA host galaxy population(s) and to directly measure the in-situ star formation rates of gas-rich galaxies at z>2.

  12. Mango starch degradation. II. The binding of alpha-amylase and beta-amylase to the starch granule.

    Science.gov (United States)

    Peroni, Fernanda Helena Gonçalves; Koike, Claudia; Louro, Ricardo Pereira; Purgatto, Eduardo; do Nascimento, João Roberto Oliveira; Lajolo, Franco Maria; Cordenunsi, Beatriz Rosana

    2008-08-27

    During mango ripening, soluble sugars that account for mango sweetening are accumulated through carbon supplied by both photosynthesis and starch degradation. The cultivar Keitt has a characteristic dependence on sugar accumulation during starch degradation, which takes place during ripening, only a few days after detachment from the tree. Most knowledge about starch degradation is based on seeds and leaves currently used as models. However, information about the mango fruit is scarce. This work presents the evaluation of alpha- and beta-amylases in the starch granule surface during fruit development and ripening. Extractable proteins were assayed for amylase activity and detected by immunofluorescence microscopy and correlated to gene expression. The results suggest that both amylases are involved in starch degradation during mango ripening, probably under the dependence of another signal triggered by the detachment from the mother-plant.

  13. Mutant U5A cells are complemented by an interferon-alpha beta receptor subunit generated by alternative processing of a new member of a cytokine receptor gene cluster.

    OpenAIRE

    Lutfalla, G; Holland, S J; Cinato, E; Monneron, D; Reboul, J.; Rogers, N C; J. M. Smith; Stark, G R; Gardiner, K.; Mogensen, K E

    1995-01-01

    The cellular receptor for the alpha/beta interferons contains at least two components that interact with interferon. The ifnar1 component is well characterized and a putative ifnar2 cDNA has recently been identified. We have cloned the gene for ifnar2 and show that it produces four different transcripts encoding three different polypeptides that are generated by exon skipping, alternative splicing and differential use of polyadenylation sites. One polypeptide is likely to be secreted and two ...

  14. A resected case of metachronous liver metastasis from lung cancer producing alpha-fetoprotein (AFP) and protein induced by vitamin K absence or antagonist II (PIVKA-II).

    Science.gov (United States)

    Oshiro, Yukio; Takada, Yasutsugu; Enomoto, Tsuyoshi; Fukao, Katashi; Ishikawa, Shigemi; Iijima, Tatsuo

    2004-01-01

    A resected case of huge liver metastasis of hepatoid adenocarcinoma of the lung is described. A 77-year-old man who presented a solitary huge liver tumor was admitted to our hospital. He had undergone right lower lobectomy of the lung for lung cancer one year before. The view of imaging studies was not a typical one of hepatocellular carcinoma. Serum levels of AFP and PIVKA-II were 334,500ng/mL and 3,890mAU/mL, respectively, and the proportion of AFP L3 was 97.9%. It was thought that they were strongly diagnostic for hepatocellular carcinoma. Extended right lobectomy of the liver was performed. Microscopically, it was poorly differentiated adenocarcinoma and diagnosed as liver metastasis from the formerly resected lung cancer. The tumor was composed of cells with both sheet-like growth and tubule formation. The neoplastic cells, in the sheet-like growth resembled hepatocellular carcinoma cells. By immunohistochemical staining with anti-AFP and anti-PIVKA-II antibodies, cancer cells of both the primary and metastatic lesions were positive. The patient eventually died of multiple liver and bone metastasis 6 months after the operation.

  15. A dynamic model of interactions of Ca2+, calmodulin, and catalytic subunits of Ca2+/calmodulin-dependent protein kinase II.

    Directory of Open Access Journals (Sweden)

    Shirley Pepke

    2010-02-01

    Full Text Available During the acquisition of memories, influx of Ca2+ into the postsynaptic spine through the pores of activated N-methyl-D-aspartate-type glutamate receptors triggers processes that change the strength of excitatory synapses. The pattern of Ca2+influx during the first few seconds of activity is interpreted within the Ca2+-dependent signaling network such that synaptic strength is eventually either potentiated or depressed. Many of the critical signaling enzymes that control synaptic plasticity,including Ca2+/calmodulin-dependent protein kinase II (CaMKII, are regulated by calmodulin, a small protein that can bindup to 4 Ca2+ ions. As a first step toward clarifying how the Ca2+-signaling network decides between potentiation or depression, we have created a kinetic model of the interactions of Ca2+, calmodulin, and CaMKII that represents our best understanding of the dynamics of these interactions under conditions that resemble those in a postsynaptic spine. We constrained parameters of the model from data in the literature, or from our own measurements, and then predicted time courses of activation and autophosphorylation of CaMKII under a variety of conditions. Simulations showed that species of calmodulin with fewer than four bound Ca2+ play a significant role in activation of CaMKII in the physiological regime,supporting the notion that processing of Ca2+ signals in a spine involves competition among target enzymes for binding to unsaturated species of CaM in an environment in which the concentration of Ca2+ is fluctuating rapidly. Indeed, we showed that dependence of activation on the frequency of Ca2+ transients arises from the kinetics of interaction of fluctuating Ca2+with calmodulin/CaMKII complexes. We used parameter sensitivity analysis to identify which parameters will be most beneficial to measure more carefully to improve the accuracy of predictions. This model provides a quantitative base from which to build more complex dynamic

  16. QUANTITATION OF DNA TOPOISOMERASE-II-ALPHA MESSENGER-RIBONUCLEIC-ACID LEVELS IN A SMALL-CELL LUNG-CANCER CELL-LINE AND 2 DRUG-RESISTANT SUBLINES USING A POLYMERASE CHAIN REACTION-AIDED TRANSCRIPT TITRATION ASSAY

    NARCIS (Netherlands)

    WITHOFF, S; SMIT, EF; MEERSMA, GJ; van den Berg, Anke; TIMMERBOSSCHA, H; KOK, K; POSTMUS, PE; MULDER, NH; DEVRIES, EGE; BUYS, CHCM

    1994-01-01

    BACKGROUND: We have modified a polymerase chain reaction (PCR)-aided transcript titration assay (1) in order to allow quantitation of low amounts of DNA topoisomerase II alpha mRNA in small RNA samples. EXPERIMENTAL DESIGN: The titration assay was used to quantitate the amount of DNA topoisomerase I

  17. Alpha Thalassemia

    Science.gov (United States)

    Alpha Thalassemia Physicians often mistake alpha thalassemia trait for iron deficiency anemia and incorrectly prescribe iron supplements that have no effect 1 on the anemia. αα αα Normal alpha ...

  18. Isolation and characterization of cDNA encoding the alpha subunit of Cap Z(36/32), an actin-capping protein from the Z line of skeletal muscle.

    OpenAIRE

    Casella, J F; Casella, S J; Hollands, J. A.; Caldwell, J E; Cooper, J A

    1989-01-01

    cDNA encoding the alpha chain of Cap Z has been isolated by screening a lambda gt11 library with affinity-purified antibodies. A single cDNA insert (designated CE2) of 2153 base pairs (bp) contains an open reading frame of 836 bp, which is incomplete at its 5' end. The technique of "rapid amplification of cDNA ends" has been used to extend the 5' end of this open reading frame to a potential transcription initiation site that is preceded by 320 bp of an apparently untranslated region. The pro...

  19. Functional Diversification of Maize RNA Polymerase IV and V subtypes via Alternative Catalytic Subunits

    Energy Technology Data Exchange (ETDEWEB)

    Haag, Jeremy R.; Brower-Toland, Brent; Krieger, Elysia K.; Sidorenko, Lyudmila; Nicora, Carrie D.; Norbeck, Angela D.; Irsigler, Andre; LaRue, Huachun; Brzeski, Jan; Mcginnis, Karen A.; Ivashuta, Sergey; Pasa-Tolic, Ljiljana; Chandler, Vicki L.; Pikaard, Craig S.

    2014-10-01

    Unlike nuclear multisubunit RNA polymerases I, II, and III, whose subunit compositions are conserved throughout eukaryotes, plant RNA polymerases IV and V are nonessential, Pol II-related enzymes whose subunit compositions are still evolving. Whereas Arabidopsis Pols IV and V differ from Pol II in four or five of their 12 subunits, respectively, and differ from one another in three subunits, proteomic ana- lyses show that maize Pols IV and V differ from Pol II in six subunits but differ from each other only in their largest subunits. Use of alternative catalytic second subunits, which are nonredundant for development and paramutation, yields at least two sub- types of Pol IV and three subtypes of Pol V in maize. Pol IV/Pol V associations with MOP1, RMR1, AGO121, Zm_DRD1/CHR127, SHH2a, and SHH2b extend parallels between paramutation in maize and the RNA-directed DNA methylation pathway in Arabidopsis.

  20. The significance of Epstein Barr Virus (EBV & DNA Topoisomerase II alpha (DNA-Topo II alpha immunoreactivity in normal oral mucosa, Oral Epithelial Dysplasia (OED and Oral Squamous Cell Carcinoma (OSCC

    Directory of Open Access Journals (Sweden)

    Osman Mohamed M

    2008-11-01

    Full Text Available Abstract Background Head and neck cancer including oral cancer is considered to develop by accumulated genetic alterations and the major pathway is cancerization from lesions such as intraepithelial dysplasia in oral leukoplakia and erythroplakia. The relationship of proliferation markers with the grading of dysplasia is uncertain. The involvement of EBV in oral carcinogenesis is not fully understood. Aim The present study was designed to investigate the role of EBV and DNA Topoisomerase II∝ (DNA-Topo II∝ during oral carcinogenesis and to examine the prognostic significance of these protein expressions in OSCCs. Methods Using specific antibodies for EBV and DNA-Topo II∝, we examined protein expressions in archival lesion tissues from 16 patients with oral epithelial dysplasia, 22 oral squamous cell carcinoma and 20 normal oral mucosa by immunohistochemistry. Clinical information was obtained through the computerized retrospective database from the tumor registry. Results DNA-Topo II∝ was expressed in all examined specimens. Analysis of Variance ANOVA revealed highly significant difference (P 0.05 in inferior surface of tongue and in hard palatal tissues. Significant differences were observed between OEDs and NSE (P Conclusion EBV and DNA Topo II-αLI expression are possible indicators in oral carcinogenesis and may be valuable diagnostic and prognostic indices in oral carcinoma.

  1. PI3KC2{alpha}, a class II PI3K, is required for dynamin-independent internalization pathways

    DEFF Research Database (Denmark)

    Krag, Claudia; Malmberg, Emily Kim; Salcini, Anna Elisabetta

    2010-01-01

    Increasing evidence indicates that cellular uptake of several molecules can occur independently of functional dynamin, but the molecular players that regulate dynamin-independent endocytosis and the subsequent trafficking steps are still largely unknown. A survival-based short-hairpin (sh) RNA...... screen using a cell line expressing a diphtheria toxin receptor (DTR, officially known as HBEGF) anchored to GPI (DTR-GPI), which internalizes diphtheria toxin (DT, officially known as DTX) in a dynamin-independent manner, identified PI3KC2a, a class II phosphoinositide 3-kinase (PI3K), as a specific...... regulator of dynamin-independent DT internalization. We found that the internalization of several proteins that enter the cell through dynamin-independent pathways led to a relocalization of PI3KC2a to cargo-positive vesicles. Furthermore, downregulation of PI3KC2a impaired internalization of CD59 as well...

  2. Role of the beta subunit of casein kinase-2 on the stability and specificity of the recombinant reconstituted holoenzyme

    DEFF Research Database (Denmark)

    Meggio, F; Boldyreff, B; Marin, O;

    1992-01-01

    Recombinant human alpha subunit from casein kinase-2 (CK-2) was subjected, either alone or in combination with recombinant human beta subunit, to high temperature, tryptic digestion and urea treatment. In all three cases, it was shown that the presence of the beta subunit could drastically reduce...

  3. Assembly processes in oligomers containing structurally distinct subunits. [Hemoglobin, Hemocyanin

    Energy Technology Data Exchange (ETDEWEB)

    Bonaventura, C. (Duke Univ. Marine Laboratory, Beaufort, NC); Bonaventura, J.; Brouwer, M.

    1980-10-01

    There are two major classes of oxygen carrying proteins: the hemoglobins and the hemocyanins. Thetrameric hemoglobin is an oxygen carrier that has long served as a model in the analysis of allostery in proteins. In assembly processes as well, the oxygen carrying proteins appear to be good model systems which illustrate the distinct roles played by structurally diverse subunits. Thetrameric human hemoglobin shows definite differences in assembly and tetrameric stability depending on alpha-beta, alpha-alpha, beta-beta, alpha-gamma, etc., interactions. The blue-colored hemocyanins are found in the hemolymph of many molluscs and arthropods. In these molecules, oxygen binds at dimeric copper centers. Te reactivity toward oxygen is typically modulated by external factors such as pH and sodium chloride. Because of their extremely large size and subunit diversity, the hemocyanins may be particularly useful as assembly models.

  4. Vascular smooth muscle cells express the alpha(1A) subunit of a P-/Q-type voltage-dependent Ca(2+)Channel, and It is functionally important in renal afferent arterioles

    DEFF Research Database (Denmark)

    Hansen, Pernille B. Lærkegaard; Jensen, Boye L.; Andreasen, D

    2000-01-01

    in rat aorta, brain, aortic smooth muscle cells (A7r5), VSMCs, and mesangial cells. Immunolabeling with an anti-alpha(1A) antibody was positive in acid-macerated, microdissected preglomerular vessels and in A7r5 cells. Patch-clamp experiments on aortic A7r5 cells showed 22+/-4% (n=6) inhibition of inward...... Ca(2+) current by omega-Agatoxin IVA (10(-8) mol/L), which in this concentration is a specific inhibitor of P-type VDCCs. Measurements of intracellular Ca(2+) in afferent arterioles with fluorescence-imaging microscopy showed 32+/-9% (n=10) inhibition of the K(+)-induced rise in Ca(2...... preglomerular resistance vessels and aorta, as well as mesangial cells, and that P-type VDCCs contribute to Ca(2+) influx in aortic and renal VSMCs and are involved in depolarization-mediated contraction in renal afferent arterioles....

  5. Differential stimulation by CCAAT/enhancer-binding protein alpha isoforms of the estrogen-activated promoter of the very-low-density apolipoprotein II gene

    NARCIS (Netherlands)

    Calkhoven, CF; Snippe, L; Ab, G

    1997-01-01

    The transcription factors CCAAT/enhancer-binding proteins alpha and beta (C/EBP alpha and C/EBP beta) are highly expressed in liver and are believed to function in maintaining the differentiated state of the hepatocytes, C/EBP alpha appears to be a critical regulator of genes involved in metabolic p

  6. HEAD INJURY ASSESSMENT IN JUVENILE CHINOOK USING THE ALPHA II-SPECTRIN BIOMARKER: EFFECTS OF PRESSURE CHANGES AND PASSAGE THROUGH A REMOVABLE SPILLWAY WEIR

    Energy Technology Data Exchange (ETDEWEB)

    Jonason, C.; Miracle, A.

    2009-01-01

    The cytoskeletal protein alpha II-spectrin has specifi c neurodegenerative mechanisms that allow the necrotic (injury-induced) and apoptotic (non-injury-induced) pathways of proteolysis to be differentiated in an immunoblot. Consequently, αII-spectrin breakdown products (SBDPs) are potential biomarkers for diagnosing traumatic brain injury (TBI). The purpose of the following investigation, consisting of two studies, was to evaluate the utility of the spectrin biomarker in diagnosing TBI in fi sh that travel through hydroelectric dams in the Columbia and Snake Rivers. The fi rst study used hyperbaric pressure chambers to simulate the pressure changes that affect fi sh during passage through a Federal Columbia River Power System (FCRPS) Kaplan turbine. The second study tested the effect of a removable spillway weir (RSW) on the passage of juvenile chinook (Oncorhynchus tshawytscha). This study was conducted in tandem with a balloon-tag study by the U.S. Army Corps of Engineers. Brain samples from fi sh were collected and analyzed using an immunoblot for SBDPs, and imaging software was used to quantify the protein band density and determine the ratio of cleaved protein to total protein. The biomarker analyses found higher SBDP expression levels in fi sh that were exposed to lower pressure nadirs and fi sh that passed through the RSW at a deep orientation. In general, the incidence of injuries observed after treatment positively correlated with expression levels, suggesting that the biomarker method of analysis is comparable to traditional methods of injury assessment. It was also found that, for some treatments, the 110 kDa spectrin fragment (SBDP 110) correlated more strongly with necrotic head injury incidence and mortality rates than did the total cleaved protein or the 120 kDa fragment. These studies will be informative in future decisions regarding the design of turbines and fi sh passage structures in hydroelectric dams and will hopefully contribute to the

  7. Genetic conservation of hlyA determinants and serological conservation of HlyA: basis for developing a broadly cross-reactive subunit Escherichia coli alpha-hemolysin vaccine.

    Science.gov (United States)

    O'Hanley, P; Marcus, R; Baek, K H; Denich, K; Ji, G E

    1993-03-01

    The HlyA determinant among Escherichia coli isolates from patients with symptomatic urinary tract infection was compared in this report with a prototype HlyA encoded by pSF4000 by DNA-DNA hybridization tests with 20-base synthetic oligonucleotides and monoclonal antibody binding and neutralization assays. Hybridization results demonstrated that 349 (98%) of 357 definitive reactions among 54 hemolytic strains shared homology with seven DNA probes spanning many HlyA regions corresponding to residues (R) 41 to 47, 55 to 61, 248 to 254, 306 to 312, 336 to 343, 402 to 408, and 929 to 935. Genetic divergence was identified by lack of hybridization signals among 17 to 76% of the hemolytic strains within the distal portion of a predicted hydrophobic region corresponding to R491 to 319 and within a predicted hydrophilic region corresponding to R491 to 497 and R532 to 538. Serological studies demonstrated that 26 (81%) culture supernatants of 32 hemolytic strains were bound by all 12 monoclonal anti-HlyA antibodies. Among five of six remaining strains, the culture supernatants were bound by 3 to 11 monoclonal antibody preparations. There was only one hemolytic culture supernatant that failed to be bound by any monoclonal antibody, although the strain hybridized with nine hemolysin DNA probes. In addition, hemolytic activity of all 24 different culture supernatants tested was reduced by at least twofold by one monoclonal antibody specific for R2-161. These data extend and support previous views that the HlyA determinant is conserved among E. coli strains and suggest that a broadly cross-reactive HlyA subunit vaccine can be developed.

  8. Conformational characterization of human eukaryotic initiation factor 2alpha: a single tryptophan protein.

    Science.gov (United States)

    Sreejith, R K; Yadav, Viveka Nand; Varshney, Nishant K; Berwal, Sunil K; Suresh, C G; Gaikwad, Sushama M; Pal, Jayanta K

    2009-12-11

    The alpha-subunit of the human eukaryotic initiation factor 2 (heIF2alpha), a GTP binding protein, plays a major role in the initiation of protein synthesis. During various cytoplasmic stresses, eIF2alpha gets phosphorylated by eIF2alpha-specific kinases resulting in inhibition of protein synthesis. The cloned and over expressed heIF2alpha, a protein with a single tryptophan (trp) residue was examined for its conformational characteristics using steady-state and time-resolved tryptophan fluorescence, circular dichroism (CD) and hydrophobic dye binding. The steady-state fluorescence spectrum, fluorescence lifetimes (tau(1)=1.13ns and tau(2)=4.74ns) and solute quenching studies revealed the presence of trp conformers in hydrophobic and differential polar environment at any given time. Estimation of the alpha-helix and beta-sheet content showed: (i) more compact structure at pH 2.0, (ii) distorted alpha-helix and rearranged beta-sheet in presence of 4M guanidine hydrochloride and (iii) retention of more than 50% ordered structure at 95 degrees C. Hydrophobic dye binding to the protein with loosened tertiary structure was observed at pH 2.0 indicating the existence of a molten globule-like structure. These observations indicate the inherent structural stability of the protein under various denaturing conditions.

  9. Spillway-induced salmon head injury triggers the generation of brain alphaII-spectrin breakdown product biomarkers similar to mammalian traumatic brain injury.

    Directory of Open Access Journals (Sweden)

    Ann Miracle

    Full Text Available Recent advances in biomedical research have resulted in the development of specific biomarkers for diagnostic testing of disease condition or physiological risk. Of specific interest are alphaII-spectrin breakdown products (SBDPs, which are produced by proteolytic events in traumatic brain injury and have been used as biomarkers to predict the severity of injury in humans and other mammalian brain injury models. This study describes and demonstrates the successful use of antibody-based mammalian SBDP biomarkers to detect head injury in migrating juvenile Chinook salmon (Oncorhynchus tshawytscha that have been injured during passage through high-energy hydraulic environments present in spillways under different operational configurations. Mortality and injury assessment techniques currently measure only near-term direct mortality and easily observable acute injury. Injury-based biomarkers may serve as a quantitative indicator of subacute physical injury and recovery, and aid hydropower operators in evaluation of safest passage configuration and operation actions for migrating juvenile salmonids. We describe a novel application of SBDP biomarkers for head injury for migrating salmon. To our knowledge, this is the first documented cross-over use of a human molecular biomarker in a wildlife and operational risk management scenario.

  10. Spillway-induced salmon head injury triggers the generation of brain alphaII-spectrin breakdown product biomarkers similar to mammalian traumatic brain injury.

    Science.gov (United States)

    Miracle, Ann; Denslow, Nancy D; Kroll, Kevin J; Liu, Ming Cheng; Wang, Kevin K W

    2009-01-01

    Recent advances in biomedical research have resulted in the development of specific biomarkers for diagnostic testing of disease condition or physiological risk. Of specific interest are alphaII-spectrin breakdown products (SBDPs), which are produced by proteolytic events in traumatic brain injury and have been used as biomarkers to predict the severity of injury in humans and other mammalian brain injury models. This study describes and demonstrates the successful use of antibody-based mammalian SBDP biomarkers to detect head injury in migrating juvenile Chinook salmon (Oncorhynchus tshawytscha) that have been injured during passage through high-energy hydraulic environments present in spillways under different operational configurations. Mortality and injury assessment techniques currently measure only near-term direct mortality and easily observable acute injury. Injury-based biomarkers may serve as a quantitative indicator of subacute physical injury and recovery, and aid hydropower operators in evaluation of safest passage configuration and operation actions for migrating juvenile salmonids. We describe a novel application of SBDP biomarkers for head injury for migrating salmon. To our knowledge, this is the first documented cross-over use of a human molecular biomarker in a wildlife and operational risk management scenario.

  11. Retention behaviour of proteins on poly(vinylimidazole)-copper(II) complexes supported on silica: application to the fractionation of desialylated human alpha 1-acid glycoprotein variants.

    Science.gov (United States)

    Millot, M C; Hervé, F; Sébille, B

    1995-02-03

    The retention behaviour of various amino acids, peptides and proteins on poly(vinylimidazole)-Cu(II) complexes supported on silica was investigated. Free amino acids and peptides containing one histidine and in some instances one additional tryptophan residue in their primary structure were found to elute from the supports only after addition of a competing complexing agent to the mobile phase. However, the results obtained the proteins containing metal binding groups suggested that, in addition to the presence of donor-acceptor interactions between the macromolecules and the immobilized metal, other additional (essentially ionic and/or hydrophobic) interactions took place between the proteins and the surrounding of the metal. When donor-acceptor interactions were predominant, proteins were strongly adsorbed on the stationary phase and their elution required the addition of a competing complexing agent in the mobile phase. However, when the binding between the proteins and the supports via donor-acceptor interactions was less favourable, proteins were eluted from the columns without the addition of a competing agent in the mobile phase. With respect to the binding of these proteins, ionic and/or hydrophobic interactions were no longer negligible during the chromatographic process and the retention of the macromolecules by the stationary phase depended on the elution conditions (ionic strength, pH, etc.). These supports were used in the fractionation of the three main genetic variants of desialylated alpha 1-acid glycoprotein.

  12. PKA regulatory subunit expression in tooth development.

    Science.gov (United States)

    de Sousa, Sílvia Ferreira; Kawasaki, Katsushige; Kawasaki, Maiko; Volponi, Ana Angelova; Gomez, Ricardo Santiago; Gomes, Carolina Cavaliéri; Sharpe, Paul T; Ohazama, Atsushi

    2014-05-01

    Protein kinase A (PKA) plays critical roles in many biological processes including cell proliferation, cell differentiation, cellular metabolism and gene regulation. Mutation in PKA regulatory subunit, PRKAR1A has previously been identified in odontogenic myxomas, but it is unclear whether PKA is involved in tooth development. The aim of the present study was to assess the expression of alpha isoforms of PKA regulatory subunit (Prkar1a and Prkar2a) in mouse and human odontogenesis by in situ hybridization. PRKAR1A and PRKAR2A mRNA transcription was further confirmed in a human deciduous germ by qRT-PCR. Mouse Prkar1a and human PRKAR2A exhibited a dynamic spatio-temporal expression in tooth development, whereas neither human PRKAR1A nor mouse Prkar2a showed their expression in odontogenesis. These isoforms thus showed different expression pattern between human and mouse tooth germs. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Galaxy counterparts of metal-rich damped Lyman-alpha absorbers - II. A solar-metallicity, molecular-rich, and dusty DLA at z_abs=2.58

    CERN Document Server

    Fynbo, J P U; Noterdaeme, P; Christensen, L; Moller, P; Durgapal, A K; Goldoni, P; Kaper, L; Krogager, J -K; Laursen, P; Maund, J R; Milvang-Jensen, B; Okoshi, K; Rasmussen, P K; Thorsen, T J; Toft, S; Zafar, T

    2010-01-01

    [Abridged]. Here, we report on the discovery of the galaxy counterpart of the z_abs=2.58 DLA on the line-of-sight to the z=3.07 quasar SDSS J091826.16+163609.0. The galaxy counterpart of the DLA is detected in the OIII 5007 and OII 3726,3729 emission lines redshifted into the NIR at an impact parameter of 16 kpc. Ly-alpha emission is not detected. The upper limit implies that Ly-alpha emission from this galaxy is suppressed by more than an order of magnitude. The DLA is amongst the most metal-rich DLAs studied so far at comparable redshifts. We find evidence for substantial depletion of refractory elements onto dust grains. Fitting the main metal line component of the DLA, which is located at z_abs=2.5832 and accounts for at least 85% of the total column density of low-ionisation species, we measure metal abundances from ZnII, SII, SiII, CrII, MnII, FeII and NiII of -0.12, -0.26, -0.46, -0.88, -0.92, -1.03 and -0.78, respectively. In addition, we detect absorption in the Lyman and Werner bands of hydrogen, wh...

  14. GABA receptor subunit composition relative to insecticide potency and selectivity.

    Science.gov (United States)

    Ratra, G S; Casida, J E

    2001-07-01

    Three observations on the 4-[(3)H]propyl-4'-ethynylbicycloorthobenzoate ([(3)H]EBOB) binding site in the gamma-aminobutyric acid (GABA) receptor indicate the specific target for insecticide action in human brain and a possible mechanism for selectivity. First, from published data, alpha-endosulfan, lindane and fipronil compete for the [(3)H]EBOB binding site with affinities of 0.3--7 nM in both human recombinant homooligomeric beta 3 receptors and housefly head membranes. Second, from structure-activity studies, including new data, GABAergic insecticide binding potency on the pentameric receptor formed from the beta 3 subunit correlates well with that on the housefly receptor (r=0.88, n=20). This conserved inhibitor specificity is consistent with known sequence homologies in the housefly GABA receptor and the human GABA(A) receptor beta 3 subunit. Third, as mostly new findings, various combinations of alpha 1, alpha 6, and gamma 2 subunits coexpressed with a beta 1 or beta 3 subunit confer differential insecticide binding sensitivity, particularly to fipronil, indicating that subunit composition is a major factor in insecticide selectivity.

  15. Differential expression of BK channel isoforms and beta-subunits in rat neuro-vascular tissues

    DEFF Research Database (Denmark)

    Poulsen, Asser Nyander; Johansson, Helle Wulf; Hay-Schmidt, Anders

    2009-01-01

    We investigated the expression of splice variants and beta-subunits of the BK channel (big conductance Ca(2+)-activated K(+) channel, Slo1, MaxiK, K(Ca)1.1) in rat cerebral blood vessels, meninges, trigeminal ganglion among other tissues. An alpha-subunit splice variant X1(+24) was found expresse...

  16. A-Raf kinase is a new interacting partner of protein kinase CK2 beta subunit

    DEFF Research Database (Denmark)

    Boldyreff, B; Issinger, O G

    1997-01-01

    In a search for protein kinase CK2 beta subunit binding proteins using the two-hybrid system, more than 1000 positive clones were isolated. Beside clones for the alpha' and beta subunit of CK2, there were clones coding for a so far unknown protein, whose partial cDNA sequence was already deposite...

  17. Crystal Structure of the Cytoplasmic N-Terminal Domain of Subunit I, a Homolog of Subunit a, of V-ATPase

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, Sankaranarayanan; Vyas, Nand K.; Baker, Matthew L.; Quiocho, Florante A. (Baylor)

    2012-02-27

    Subunit 'a' is associated with the membrane-bound (VO) complex of eukaryotic vacuolar H{sup +}-ATPase acidification machinery. It has also been shown recently to be involved in diverse membrane fusion/secretory functions independent of acidification. Here, we report the crystal structure of the N-terminal cytosolic domain from the Meiothermus ruber subunit 'I' homolog of subunit a. The structure is composed of a curved long central {alpha}-helix bundle capped on both ends by two lobes with similar {alpha}/{beta} architecture. Based on the structure, a reasonable model of its eukaryotic subunit a counterpart was obtained. The crystal structure and model fit well into reconstructions from electron microscopy of prokaryotic and eukaryotic vacuolar H{sup +}-ATPases, respectively, clarifying their orientations and interactions and revealing features that could enable subunit a to play a role in membrane fusion/secretion.

  18. Stereoselective reduction of carbonyl compounds with Actinomycete: purification and characterization of three alpha-keto ester reductases from Streptomyces avermitilis.

    Science.gov (United States)

    Ishihara, Kohji; Kato, Chiaki; Yamaguchi, Hitomi; Iwai, Rieko; Yoshida, Momoko; Ikeda, Natsumi; Hamada, Hiroki; Masuoka, Noriyoshi; Nakajima, Nobuyoshi

    2008-12-01

    We achieved the purification of three alpha-keto ester reductases (Streptomyces avermitilis keto ester reductase, SAKERs-I, -II, and -III) from Streptomyces avermitilis NBRC14893 whole cells. The molecular masses of the native SAKERs-I, -II, and -III were estimated to be 72, 38, and 36 kDa, respectively, by gel filtration chromatography. The subunit molecular masses of SAKERs-I, -II, and -III were also estimated to be 32, 32, and 34 kDa, respectively, by SDS-polyacrylamide gel electrophoresis. The purified SAKERs-II and -III showed a reducing activity for alpha-keto esters (in particular, for ethyl pyruvate). SAKER-I showed a high reducing activity not only toward the alpha- and beta-keto esters, but also toward alpha-keto acid. The N-terminal region amino acid sequences of SAKERs-I, -II, and -III were identical to that of a putative oxidoreductase, SAV2750, a putative oxidoreductase, SAV1849, and a putative oxidoreductase, SAV4117, respectively, hypothetical proteins coded on the S. avermitilis genome.

  19. Topoisomerase II alpha gene copy loss has adverse prognostic significance in ERBB2-amplified breast cancer: a retrospective study of paraffin-embedded tumor specimens and medical charts

    Directory of Open Access Journals (Sweden)

    Zhu April

    2008-08-01

    Full Text Available Abstract Background Amplification of the ERBB2 (Her-2/neu oncogene, which occurs in approximately 25% of breast carcinomas, is a known negative prognostic factor. Available data indicate that a variable number of nearby genes on chromosome 17q may be co-amplified or deleted, forming a continuous amplicon of variable size. In approximately 25% of these patients, the amplicon extends to the gene for topoisomerase II alpha (TOP2A, a target for anthracyclines. We sought to understand the significance of these associated genomic changes for breast cancer prognosis and predicting response to therapy. Methods and patients Archival tissue samples from 63 breast cancer patients with ERBB2 amplification, stages 0–IV, were previously analyzed with FISH probes for genes located near ERBB2. In the present study, the clinical outcome data were determined for all patients presenting at stages I–III for whom adequate clinical follow up was available. Results Four amplicon patterns (Classes were identified. These were significantly associated with the clinical outcome, specifically, recurrence of breast cancer. The Amplicon class IV with deleted TOP2A had 67% (6/9 cases with recurrence, whereas the other three classes combined had only 12% (3/25 cases (p-value = 0.004 at the time of last follow-up. TOP2A deletion was also significantly associated with time to recurrence (p-value = 0.0002. After adjusting for age in Cox regression analysis, the association between TOP2A deletion and time to recurrence remains strongly significant (p-value = 0.002 whereas the association with survival is marginally significant (p-value = 0.06. Conclusion TOP2A deletion is associated with poor prognosis in ERBB2-amplified breast carcinomas. Clarification of the mechanism of this association will require additional study.

  20. High frequency of acid alpha-glucosidase pseudodeficiency complicates newborn screening for glycogen storage disease type II in the Japanese population.

    Science.gov (United States)

    Kumamoto, Shingo; Katafuchi, Tatsuya; Nakamura, Kimitoshi; Endo, Fumio; Oda, Eri; Okuyama, Torayuki; Kroos, Marian A; Reuser, Arnold J J; Okumiya, Toshika

    2009-07-01

    To investigate the feasibility of newborn screening for glycogen storage disease type II (GSDII; Pompe disease or acid maltase deficiency) in the Japanese population, we assayed the acid alpha-glucosidase activity in dried blood spots from 715 Japanese newborns and 18 previously diagnosed patients using a fluorometric procedure. The enzyme activity of apparently healthy newborns showed a bimodal distribution. The median activity of the minor group (31 individuals, 4.3% of the samples) was 6.5 times lower than that of the major group. Four of the 715 control samples (0.56%) fell in the patient range. We then analyzed genomic DNA, extracted from the same blood spots, for the occurrence of two sequence variants, c.1726G>A and c.2065G>A, known to cause "pseudodeficiency". This analysis revealed that 27 of 28 individuals homozygous for c.[1726A; 2065A] belonged to the minor group. One c.[1726A; 2065A] homozygote had just slightly higher activity. Twelve of the 18 patients with GSDII either had one (9 cases) or two (3 cases) c.[1726A; 2065A] alleles. The frequency of this allele was double in the patient compared to the control group (0.42 vs 0.19) at the expense of a lower frequency of the c.[1726G; 2065G] and c.[1726G; 2065A] alleles (0.58 vs 0.71 and 0 vs 0.1). These findings illustrate that c.[1726A; 2065A] homozygosity among apparently healthy individuals (3.9 per 100) complicates newborn screening for GSDII in Japan, and further that one or more pathogenic mutations are associated with the c.[1726A; 2065A] allele.

  1. Subunit structure of 6-phosphofructokinase from brewers' yeast.

    Science.gov (United States)

    Tamaki, N; Hess, B

    1975-11-01

    An analysis of 6-phosphofructokinase from brewers' yeast in the presence of sodium dodecylsulfate reveals the occurrence of four components with the following molecular weights: alpha = 140000, beta = 130000, and alpha' = 92000, beta' = 87000. It was found that the alpha- and beta-components can be converted to the alpha' and beta' components by treatment of the native preparation with hyaluronidase. A comparison of the molecular weight obtained by ultracentrifugation and gel filtration with the results obtained by dodecylsulfate electrophoresis after treatment with hyaluronidase reveals that the alpha' and beta' components are the smallest molecular structures obtained upon dissociation of the native enzyme. The mechanism of action of hyaluronidase suggests a desensitization of the alpha and beta components of the enzyme towards dodecylsulfate. Thus, in the absence of hyaluronidase treatment; only an apparent molecular weight for the alpha and beta component is obtained. The analysis indicates that the native enzyme might be composed of four different subunits with an alpha, beta, alpha' and beta' configuration. It is not excluded that the native enzyme consists only of alpha- and beta-chains.

  2. Properties and subunit structure of pig heart pyruvate dehydrogenase.

    Science.gov (United States)

    Hamada, M; Hiraoka, T; Koike, K; Ogasahara, K; Kanzaki, T

    1976-06-01

    Pyruvate dehydrogenase [EC 1.2.4.1] was separated from the pyruvate dehydrogenase complex and its molecular weight was estimated to be about 150,000 by sedimentation equilibrium methods. The enzyme was dissociated into two subunits (alpha and beta), with estimated molecular weights of 41,000 (alpha) and 36,000 (beta), respectively, by polyacrylamide gel electrophoresis in sodium dodecyl sulfate. The subunits were separated by phosphocellulose column chromatography and their chemical properties were examined. The subunit structure of the pyruvate dehydrogenase was assigned as alpha2beta2. The content of right-handed alpha-helix in the enzyme molecule was estimated to be about 29 and 28% by optical rotatory dispersion and by circular dichroism, respectively. The enzyme contained no thiamine-PP, and its dehydrogenase activity was completely dependent on added thiamine-PP and partially dependent on added Mg2+ and Ca2+. The Km value of pyruvate dehydrogenase for thiamine diphosphate was estimated to be 6.5 X 10(-5) M in the presence of Mg2+ or Ca2+. The enzyme showed highly specific activity for thiamine-PP dependent oxidation of both pyruvate and alpha-ketobutyrate, but it also showed some activity with alpha-ketovalerate, alpha-ketoisocaproate, and alpha-ketoisovalerate. The pyruvate dehydrogenase activity was strongly inhibited by bivalent heavy metal ions and by sulfhydryl inhibitors; and the enzyme molecule contained 27 moles of 5,5'-dithiobis(2-nitrobenzoic acid)-reactive sulfhydryl groups and a total of 36 moles of sulfhydryl groups. The inhibitory effect of p-chloromercuribenzoate was prevented by preincubating the enzyme with thiamine-PP plus pyruvate. The structure of pyruvate dehydrogenase necessary for formation of the complex is also reported.

  3. Conservation of helical bundle structure between the exocyst subunits.

    Directory of Open Access Journals (Sweden)

    Nicole J Croteau

    Full Text Available BACKGROUND: The exocyst is a large hetero-octomeric protein complex required for regulating the targeting and fusion of secretory vesicles to the plasma membrane in eukaryotic cells. Although the sequence identity between the eight different exocyst subunits is less than 10%, structures of domains of four of the subunits revealed a similar helical bundle topology. Characterization of several of these subunits has been hindered by lack of soluble protein for biochemical and structural studies. METHODOLOGY/PRINCIPAL FINDINGS: Using advanced hidden Markov models combined with secondary structure predictions, we detect significant sequence similarity between each of the exocyst subunits, indicating that they all contain helical bundle structures. We corroborate these remote homology predictions by identifying and purifying a predicted domain of yeast Sec10p, a previously insoluble exocyst subunit. This domain is soluble and folded with approximately 60% alpha-helicity, in agreement with our predictions, and capable of interacting with several known Sec10p binding partners. CONCLUSIONS/SIGNIFICANCE: Although all eight of the exocyst subunits had been suggested to be composed of similar helical bundles, this has now been validated by our hidden Markov model structure predictions. In addition, these predictions identified protein domains within the exocyst subunits, resulting in creation and characterization of a soluble, folded domain of Sec10p.

  4. Imidazenil: a low efficacy agonist at alpha1- but high efficacy at alpha5-GABAA receptors fail to show anticonvulsant cross tolerance to diazepam or zolpidem.

    Science.gov (United States)

    Auta, James; Impagnatiello, Francesco; Kadriu, Bashkim; Guidotti, Alessandro; Costa, Erminio

    2008-08-01

    Whereas advances in the molecular biology of GABA(A) receptor complex using knock-out and knock-in mice have been valuable in unveiling the structure, composition, receptor assembly, and several functions of different GABA(A) receptor subtypes, the mechanism(s) underlying benzodiazepine (BZ) tolerance and withdrawal remain poorly understood. Studies using specific GABA(A) receptor subunit knock-in mice suggest that tolerance to sedative action of diazepam requires long-term activation of alpha1 and alpha5 GABA(A) receptor subunits. We investigated the role of long-term activation of these GABA(A) receptor subunits during anticonvulsant tolerance using high affinity and high intrinsic efficacy ligands for GABA(A) receptors expressing the alpha5 subunit (imidazenil) or alpha1 subunit (zolpidem), and a non-selective BZ recognition site ligand (diazepam). We report here that long-term activation of GABA(A) receptors by zolpidem and diazepam but not by imidazenil elicits anticonvulsant tolerance. Although anticonvulsant cross-tolerance occurs between diazepam and zolpidem, there is no cross-tolerance between imidazenil and diazepam or zolpidem. Furthermore, diazepam or zolpidem long-term treatment decreased the expression of mRNA encoding the alpha1 GABA(A) receptor subunit in prefrontal cortex by 43% and 20% respectively. In addition, diazepam but not zolpidem long-term treatment produced a 30% increase in the expression of the alpha5 GABA(A) receptor subunit mRNA in prefrontal cortex. In contrast, imidazenil which is devoid of anticonvulsant tolerance does not elicit significant changes in the expression of alpha1 or alpha5 GABA(A) receptor subunit. These findings suggest that long-term activation of GABA(A) receptors containing the alpha1 or other subunits but not the alpha5 receptor subunit is essential for the induction of anticonvulsant tolerance.

  5. Expression, purification and crystallization of the catalytic subunit of protein kinase CK2 from Zea mays

    DEFF Research Database (Denmark)

    Guerra, B; Niefind, K; Pinna, L A

    1998-01-01

    The catalytic (alpha) subunit of protein kinase CK2 (CK2alpha) was originally cloned and overexpressed in the Escherichia coli strain pT7-7/BL21(DE3). The protein has been purified to homogeneity and crystallized. The crystals belong to the monoclinic space group C2, they have unit-cell parameter...

  6. Structure of protein kinase CK2: dimerization of the human beta-subunit

    DEFF Research Database (Denmark)

    Boldyreff, B; Mietens, U; Issinger, O G

    1996-01-01

    Protein kinase CK2 has been shown to be elevated in all so far investigated solid tumors and its catalytic subunit has been shown to serve as an oncogene product. CK2 is a heterotetrameric serine-threonine kinase composed of two catalytic (alpha and/or alpha') and two regulatory beta...

  7. Reciprocal control of retinal rod cyclic GMP phosphodiesterase by its gamma subunit and transducin.

    Science.gov (United States)

    Wensel, T G; Stryer, L

    1986-09-01

    The switching on of the cGMP phosphodiesterase (PDE) in retinal rod outer segments by activated transducin (T alpha-GTP) is a key step in visual excitation. The finding that trypsin activates PDE (alpha beta gamma) by degrading its gamma subunit and the reversal of this activation by gamma led to the proposal that T alpha-GTP activates PDE by relieving an inhibitory constraint imposed by gamma (Hurley and Stryer: J. Biol. Chem. 257:11094-11099, 1982). We report here studies showing that the addition of gamma subunit also reverses the activation of PDE by T alpha-GTP-gamma S. A procedure for preparing gamma in high yield (50-80%) is presented. Analyses of SDS polyacrylamide gel slices confirmed that inhibitory activity resides in the gamma subunit. Nanomolar gamma blocks the activation of PDE by micromolar T alpha-GTP gamma S. The degree of activation of PDE depends reciprocally on the concentrations of gamma and T alpha-GTP gamma S. gamma remains bound to the disk membrane during the activation of PDE by transducin. The binding of gamma to the alpha beta subunits of native PDE is very tight; the dissociation constant is less than 10 pM, indicating that fewer than 1 in 1,700 PDE molecules in rod outer segments are activated in the absence of T alpha-GTP.

  8. The role of palmitoylation in functional expression of nicotinic alpha7 receptors.

    Science.gov (United States)

    Drisdel, Renaldo C; Manzana, Ehrine; Green, William N

    2004-11-17

    Neuronal alpha-bungarotoxin receptors (BgtRs) are nicotinic receptors that require as yet unidentified post-translational modifications to achieve functional expression. In this study, we examined the role of protein palmitoylation in BgtR expression. BgtR alpha7 subunits are highly palmitoylated in neurons from brain and other cells capable of BgtR expression, such as pheochromocytoma 12 (PC12) cells. In PC12 cells, alpha7 subunits are palmitoylated with a stoichiometry of approximately one palmitate per subunit, and inhibition of palmitoylation blocks BgtR expression. In cells incapable of BgtR expression, such as human embryonic kidney cells, alpha7 subunits are not significantly palmitoylated. However, in these same cells, chimeric subunits with the N-terminal half of alpha7 fused to the C-terminal half of serotonin-3A receptor (alpha7/5-HT3A) subunits form functional BgtRs that are palmitoylated to an extent similar to that of BgtRalpha7 subunits in PC12 cells. Palmitoylation of PC12 and alpha7/5-HT3A BgtRs occurred during assembly in the endoplasmic reticulum (ER). In conclusion, our data indicate a function for protein palmitoylation in which palmitoylation of assembling alpha7 subunits in the ER has a role in the formation of functional BgtRs.

  9. Topoisomerase II alpha and TLE3 as predictive markers of response to anthracycline and taxane-containing regimens for neoadjuvant chemotherapy in breast cancer

    Directory of Open Access Journals (Sweden)

    Susini T

    2014-11-01

    Full Text Available Tommaso Susini,1 Barbara Berti,1 Carlo Carriero,1 Ketty Tavella,2 Jacopo Nori,3 Ermanno Vanzi,3 Cecilia Molino,1 Mariarosaria Di Tommaso,1 Marco Santini,1 Valeria Saladino,4 Simonetta Bianchi4 1Department of Health Science, Gynecology Section, 2Department of Health Science, Chemotherapy Section, University of Florence, Italy; 3Diagnostic Senology Unit, Azienda Ospedaliera-Universitaria Careggi, Florence, Italy; 4Department of Surgery and Translational Medicine, Pathology Unit, University of Florence, Italy Purpose: Anthracyclines and taxanes are considered the standard for neoadjuvant chemotherapy of breast cancer, although they are often associated with serious side effects and wide variability of individual response. In this study, we analyzed the value of topoisomerase II alpha (TOP2A and transducin-like enhancer of split 3 (TLE3 as predictive markers of response to therapy with anthracyclines and taxanes. Materials and methods: TOP2A and TLE3 protein expressions were evaluated using immunohistochemistry on 28 samples, obtained by core needle biopsy in patients with locally advanced breast carcinoma, subsequently subjected to epirubicin- and paclitaxel-based neoadjuvant chemotherapy. The immunohistochemical staining was correlated with the clinical response measured by the tumor size reduction evaluated by breast magnetic resonance imaging, prior and after chemotherapy, and by pathologic evaluation of the surgical specimen. Results: Neoadjuvant chemotherapy achieved a size reduction in 26/28 tumors (92.9%, with an average percentage decrease of 45.6%. A downstaging was achieved in 71.4% of the cases of locally advanced carcinoma. TOP2A positivity was correlated with a greater reduction in tumor diameter (P=0.06; negative staining for TLE3 was predictive of a better response to neoadjuvant chemotherapy (P=0.07. A higher reduction in tumor diameter (P=0.03 was also found for tumors that were concurrently TLE3-negative and TOP2A

  10. Optical observations of the nearby galaxy IC342 with narrow band [SII] and H$\\alpha$ filters. II - Detection of 16 Optically-Identified Supernova Remnant Candidates

    CERN Document Server

    Vucetic, M M; Pavlovic, M Z; Pannuti, T G; Petrov, N; Goker, U D; Ercan, E N

    2015-01-01

    We present the detection of 16 optical supernova remnant (SNR) candidates in the nearby spiral galaxy IC342. The candidates were detected by applying [SII]/H$\\alpha$ ratio criterion on observations made with the 2 m RCC telescope at Rozhen National Astronomical Observatory in Bulgaria. In this paper, we report the coordinates, diameters, H$\\alpha$ and [SII] fluxes for 16 SNRs detected in two fields of view in the IC342 galaxy. Also, we estimate that the contamination of total H$\\alpha$ flux from SNRs in the observed portion of IC342 is 1.4%. This would represent the fractional error when the star formation rate (SFR) for this galaxy is derived from the total galaxy's H$\\alpha$ emission.

  11. TNF-alpha, produced by feline infectious peritonitis virus (FIPV)-infected macrophages, upregulates expression of type II FIPV receptor feline aminopeptidase N in feline macrophages.

    Science.gov (United States)

    Takano, Tomomi; Hohdatsu, Tsutomu; Toda, Ayako; Tanabe, Maki; Koyama, Hiroyuki

    2007-07-20

    The pathogenicity of feline infectious peritonitis virus (FIPV) is known to depend on macrophage tropism, and this macrophage infection is enhanced by mediation via anti-S antibody (antibody-dependent enhancement, ADE). In this study, we found that TNF-alpha production was increased with viral replication in macrophages inoculated with a mixture of FIPV and anti-S antibody, and demonstrated that this culture supernatant had feline PBMC apoptosis-inducing activity. We also demonstrated that the expression level of the FIPV virus receptor, feline aminopeptidase N (fAPN), was increased in macrophages of FIP cats. For upregulation of TNF-alpha and fAPN in macrophages, viral replication in macrophages is necessary, and their expressions were increased by ADE of FIPV infection. It was demonstrated that a heat-resistant fAPN-inducing factor was present in the culture supernatant of FIPV-infected macrophages, and this factor was TNF-alpha: fAPN expression was upregulated in recombinant feline TNF-alpha-treated macrophages, and FIPV infectivity was increased in these macrophages. These findings suggested that FIPV replication in macrophages increases TNF-alpha production in macrophages, and the produced TNF-alpha acts and upregulates fAPN expression, increasing FIPV sensitivity.

  12. Subunit structure of the acetylcholine receptor from Electrophorus electricus.

    Science.gov (United States)

    Conti-Tronconi, B M; Hunkapiller, M W; Lindstrom, J M; Raftery, M A

    1982-11-01

    The amino-terminal amino acid sequences of the four major peptides (Mr 41,000, 50,000, 55,000, and 62,000) present in purified preparations of Electrophorus electricus nicotinic acetylcholine receptor (AcChoR) have been determined for 24 cycles by automated sequence analysis procedures yielding four unique polypeptide sequences. The sequences showed a high degree of similarity, having identical residues in a number of positions ranging between 37% and 50% for specific pairs of subunits. Comparison of the sequences obtained with those of the subunits of similar molecular weight from Torpedo californica AcChoR revealed an even higher degree of homology (from 46% to 71%) for these two highly diverged species. Simultaneous sequence analysis of the amino termini present in native, purified Electrophorus AcChoR showed that these four related sequences were the only ones present and that they occur in a ratio of 2:1:1:1, with the smallest subunit ("alpha 1") being present in two copies. Genealogical analysis suggests that the subunits of both Torpedo and Electrophorus AcChoRs derive from a common ancestral gene, the divergence having occurred early in the evolution of the receptor. This shared ancestry and the very early divergence of the four subunits, as well as the highly conserved structure of the AcChoR complex along animal evolution, suggest that each of the subunits evolved to perform discrete crucial roles in the physiological function of the AcChoR.

  13. Transcriptional regulators of Na, K-ATPase subunits

    Directory of Open Access Journals (Sweden)

    Zhiqin eLi

    2015-10-01

    Full Text Available The Na,K-ATPase classically serves as an ion pump creating an electrochemical gradient across the plasma membrane that is essential for transepithelial transport, nutrient uptake and membrane potential. In addition, Na,K-ATPase also functions as a receptor, a signal transducer and a cell adhesion molecule. With such diverse roles, it is understandable that the Na,K-ATPase subunits, the catalytic alpha-subunit, the beta-subunit and the FXYD proteins, are controlled extensively during development and to accommodate physiological needs. The spatial and temporal expression of Na,K-ATPase is partially regulated at the transcriptional level. Numerous transcription factors, hormones, growth factors, lipids and extracellular stimuli modulate the transcription of the Na,K-ATPase subunits. Moreover, epigenetic mechanisms also contribute to the regulation of Na,K-ATPase expression. With the ever growing knowledge about diseases associated with the malfunction of Na,K-ATPase, this review aims at summarizing the best-characterized transcription regulators that modulate Na,K-ATPase subunit levels. As abnormal expression of Na,K-ATPase subunits have been observed in many carcinoma, we will also discuss transcription factors that are associated with epithelial-to-mesenchymal transition, a crucial step in the progression of many tumors to malignant disease.

  14. Differential distribution of GABAA receptor subunits in soma and processes of cerebellar granule cells: effects of maturation and a GABA agonist

    DEFF Research Database (Denmark)

    Elster, L; Hansen, Gert Helge; Belhage, B;

    1995-01-01

    or absence of the GABAA receptor agonist 4,5,6,7-tetrahydroisoxazolo[5,4c]pyridin-3-ol (THIP). THIP (150 microM) induced a 2-fold increase in the number of alpha 1 and beta 2/3 subunits in both cell bodies and processes in 4-day-old cultures. Extending the culture period to 8 days led to a polarization...... composition. Interestingly, receptor subunit clusters, consisting of alpha 1 alone, were more frequently observed than composite (alpha 1; beta 2/3) clusters. This substantiates the view that receptors not having alpha 1 and beta 2/3 subunits in the same complex may exist....

  15. Sequenciamento e análise dos genes das subunidades alfa e beta do hormônio folículo estimulante de bovino (Bos taurus indicus Sequencing and analysis of subunits alpha and beta of the follicle stimulating hormone from bovine (Bos taurus indicus

    Directory of Open Access Journals (Sweden)

    Luci Sayori Murata

    2008-07-01

    of the subunits alpha and beta of the Bos taurus indicus follicle stimulated hormone (FSH. It to compare the results of sequencing these subunits between subunits aplha and beta from swine and Bos taurus taurus previouly published in GenBank. There was a high similarity between nucleotides and predicted amino acids in the αFSH chain of Bos taurus indicus and those of swine and buffalo. In the compare the sequence of the subunit of αFSH of Bos taurus indicus with swine showed differences in three aminoacid residues with ßFSH there was a modification in the first base of the codon, which had to an alteration in the 83 amino acid residue which in Bos taurus indicus and a glycin, this was serine in Bos taurus taurus. This modification, as well as those indentyfied in cDNA of the αFSH and ßFSH chains were confirmed by cloning. The modification of serine for glycine in position 83 was the only substitute that altered the residue in the comparson between ßFSH subunit of Bos taurus indicus and Bos taurus taurus. Nevertheles this modification showld not significantly alter the physiological properties of FSH as the glycine residue was also found in the swine ßFSH, it is therefore a specific modification which distinguishes between the ßFSH of Bos taurus taurus and Bos taurus indicus.

     

    KEY WORDS: Bovine, cloning, FSH, hormone.

  16. Alpha Blockers

    Science.gov (United States)

    ... positive side, alpha blockers might decrease low-density lipoprotein (LDL) cholesterol (the "bad" cholesterol). Alpha blockers can ... PreventionTreatmentofHighBloodPressure/Types-of-Blood-Pressure-Medications_UCM_303247_Article.jsp. Accessed June 4, 2016. Kaplan NM, et ...

  17. New Action of Inhibin Alpha Subunit in Advanced Prostate Cancer

    Science.gov (United States)

    2010-02-01

    were able to obtained LEC isolated from skin to do the proposed experiments. The goal of this aim was to use LEC and culture them in the presence...transcription factor 2 0.64 0.202 LASS1 LAG1 homolog, ceramide synthase 1 (S. cerevisiae) 0.42 0.186 GDF3 Growth differentiation factor 3 0.40 0.158...domains 1 1.60 1.51 STARD4 StAR-related lipid transfer (START) domain containing 4 2.29 1.51 LOC646853 hypothetical LOC646853 1.72 1.50 PLA2G4A

  18. Association of single nucleotide polymorphisms of nicotinic acetylcholine receptor subunits with cervical neoplasia

    Science.gov (United States)

    Calleja-Macias, Itzel; Osann, Kathryn; Remedios-Chan, Mariana; Barrera-Saldana, Hugo A.; Illades-Aguiar, Berenice; Anton-Culver, Hoda; Chikova, Anna K.; Grando, Sergei A.; Bernard, Hans-Ulrich

    2014-01-01

    Aims Cholinergic signaling, particularly in response to non-physiological ligands like nicotine, stimulates carcinogenesis of a variety of tissue types including epithelia of the cervix uteri. Cholinergic signaling is mediated by nicotinic acetylcholine receptors (nAChRs), which are pentamers formed by subsets of 16 nAChR subunits. Recent literature suggests that single nucleotide polymorphisms (SNPs) of some of these subunits, notably alpha5, are risk factors for developing lung cancer in smokers as well as in non-smokers. Main methods We have studied the prevalence of four SNPs in the alpha5, alpha9, and beta1 subunits, which are expressed in cervical cells, in 456 patients with cervical cancers, precursor lesions, and healthy controls from two cohorts in Mexico. Key findings A SNP in the alpha9 subunit, the G allele of rs10009228 (alpha9, A>G) shows a significant trend in the combined cohort, indicating that this allele constitutes a risk factor for neoplastic progression. The A allele of the SNP rs16969968 (alpha5, G>A), which correlates with the development of lung cancer, shows a non-significant trend to be associated with cervical lesions. Two other SNPs, rs55633891 (alpha9, C>T) and rs17856697 (beta1, A>G), did not exhibit a significant trend. Significance Our study points to a potential risk factor of cervical carcinogenesis with importance for DNA diagnosis and as a target for intervention. PMID:22406075

  19. Structural analysis of ARC-type inhibitor (ARC-1034) binding to protein kinase A catalytic subunit and rational design of bisubstrate analogue inhibitors of basophilic protein kinases.

    Science.gov (United States)

    Lavogina, Darja; Lust, Marje; Viil, Indrek; König, Norbert; Raidaru, Gerda; Rogozina, Jevgenia; Enkvist, Erki; Uri, Asko; Bossemeyer, Dirk

    2009-01-22

    The crystal structure of a complex of the catalytic subunit (type alpha) of cAMP-dependent protein kinase (PKA C alpha) with ARC-type inhibitor (ARC-1034), the presumed lead scaffold of previously reported adenosine-oligo-arginine conjugate-based (ARC-type) inhibitors, was solved. Structural elements important for interaction with the kinase were established with specifically modified derivatives of the lead compound. On the basis of this knowledge, a new generation of inhibitors, conjugates of adenosine-4'-dehydroxymethyl-4'-carboxylic acid moiety and oligo(D-arginine), was developed with inhibitory constants well into the subnanomolar range. The structural determinants of selectivity of the new compounds were established in assays with ROCK-II and PKBgamma.

  20. Expression of neuronal nicotinic acetylcholine receptor subunit mRNAs in rat hippocampal GABAergic interneurons.

    Science.gov (United States)

    Son, Jong-Hyun; Winzer-Serhan, Ursula H

    2008-11-10

    Hippocampal inhibitory interneurons are a diverse population of cells widely scattered in the hippocampus, where they regulate hippocampal circuit activity. The hippocampus receives cholinergic projections from the basal forebrain, and functional studies have suggested the presence of different subtypes of nicotinic acetylcholine receptors (AChRs) on gamma-aminobutyric acid (GABA)ergic interneurons. Single-cell polymerase chain reaction analysis had confirmed that several nAChR subunit mRNAs are co-expressed with glutamate decarboxylase 67 (GAD67), the marker for GABAergic interneurons. In this anatomical study, we systematically investigated the co-expression of GAD67 with different nAChR subunits by using double in situ hybridization with a digoxigenin-labeled GAD67 probe and (35)S-labeled probes for nAChR subunits (alpha2, alpha3, alpha4, alpha5, alpha6, alpha7, beta2, beta3, and beta4). The results revealed that most GAD67-positive interneurons expressed beta2, and 67 % also expressed alpha7 mRNA. In contrast, mRNA expression of other subunits was limited; only 13 % of GAD67-positive neurons co-expressed alpha4, and less than 10% expressed transcripts for alpha2, alpha3, alpha5, or beta4. Most GAD67/alpha2 co-expression was located in CA1/CA3 stratum oriens, and GAD67/alpha5 co-expression was predominantly detected in CA1/CA3 stratum radiatum/lacunosum moleculare and the dentate gyrus. Expression of alpha6 and beta3 mRNAs was rarely detected in the hippocampus, and mRNAs were not co-expressed with GAD67. These findings suggest that the majority of nicotinic responses in GABAergic interneurons should be mediated by a homomeric alpha7 or heteromeric alpha7*-containing nAChRs. Other possible combinations such as alpha2beta2*, alpha4beta2*, or alpha5beta2* heteromeric nAChRs could contribute to functional nicotinic response in subsets of GABAergic interneurons but overall would have a minor role.

  1. The subunit delta-subunit b domain of the Escherichia coli F1F0 ATPase. The B subunits interact with F1 as a dimer and through the delta subunit.

    Science.gov (United States)

    Rodgers, A J; Wilkens, S; Aggeler, R; Morris, M B; Howitt, S M; Capaldi, R A

    1997-12-05

    The delta and b subunits are both involved in binding the F1 to the F0 part in the Escherichia coli ATP synthase (ECF1F0). The interaction of the purified delta subunit and the isolated hydrophilic domain of the b subunit (bsol) has been studied here. Purified delta binds to bsol weakly in solution, as indicated by NMR studies and protease protection experiments. On F1, i.e. in the presence of ECF1-delta, delta, and bsol interact strongly, and a complex of ECF1.bsol can be isolated by native gel electrophoresis. Both delta subunit and bsol are protected from trypsin cleavage in this complex. In contrast, the delta subunit is rapidly degraded by the protease when bound to ECF1 when bsol is absent. The interaction of bsol with ECF1 involves the C-terminal domain of delta as delta(1-134) cannot replace intact delta in the binding experiments. As purified, bsol is a stable dimer with 80% alpha helix. A monomeric form of bsol can be obtained by introducing the mutation A128D (Howitt, S. M., Rodgers, A. J.,W., Jeffrey, P. D., and Cox, G. B. (1996) J. Biol. Chem. 271, 7038-7042). Monomeric bsol has less alpha helix, i.e. only 58%, is much more sensitive to trypsin cleavage than dimer, and unfolds at much lower temperatures than the dimer in circular dichroism melting studies, indicating a less stable structure. The bsol dimer, but not monomer, binds to delta in ECF1. To examine whether subunit b is a monomor or dimer in intact ECF1F0, CuCl2 was used to induce cross-link formation in the mutants bS60C, bQ104C, bA128C, bG131C, and bS146C. With the exception of bS60C, CuCl2 treatment resulted in formation of b subunit dimers in all mutants. Cross-linking yield was independent of nucleotide conditions and did not affect ATPase activity. These results show the b subunit to be dimeric for a large portion of the C terminus, with residues 124-131 likely forming a pair of parallel alpha helices.

  2. Slow-dissociation effect of common signaling subunit beta c on IL5 and GM-CSF receptor assembly.

    Science.gov (United States)

    Ishino, Tetsuya; Harrington, Adrian E; Zaks-Zilberman, Meirav; Scibek, Jeffery J; Chaiken, Irwin

    2008-05-01

    Receptor activation by IL5 and GM-CSF is a sequential process that depends on their interaction with a cytokine-specific subunit alpha and recruitment of a common signaling subunit beta (betac). In order to elucidate the assembly dynamics of these receptor subunits, we performed kinetic interaction analysis of the cytokine-receptor complex formation by a surface plasmon resonance biosensor. Using the extracellular domains of receptor fused with C-terminal V5-tag, we developed an assay method to co-anchor alpha and betac subunits on the biosensor surface. We demonstrated that dissociation of the cytokine-receptor complexes was slower when both subunits were co-anchored on the biosensor surface than when alpha subunit alone was anchored. The slow-dissociation effect of betac had a similar impact on GM-CSF receptor stabilization to that of IL5. The effects were abolished by alanine replacement of either Tyr18 or Tyr344 residue in betac, which together constitute key parts of a cytokine binding epitope. The data argue that betac plays an important role in preventing the ligand-receptor complexes from rapidly dissociating. This slow-dissociation effect of betac explains how, when multiple betac cytokine receptor alpha subunits are present on the same cell surface, selective betac usage can be controlled by sequestration in stabilized cytokine-alpha-betac complexes.

  3. Specific in vitro toxicity of crude and refined petroleum products: II. Estrogen (alpha and beta) and androgen receptor-mediated responses in yeast assays.

    NARCIS (Netherlands)

    Vrabie, C.M.; Candido, A.; van Duursen, M.B.M.; Jonker, M.T.O.

    2010-01-01

    The present study is the second in a series aiming at a systematic inventory of specific toxic effects of oils. By employing a recombinant yeast stably transfected with human estrogen receptor-alpha (ERalpha) or -beta (ERbeta) or androgen receptor (AR) and expressing yeast enhanced green fluorescent

  4. Interaction between CK2α and CK2β, the Subunits of Protein Kinase CK2: Thermodynamic Contributions of Key Residues on the CK2α Surface

    DEFF Research Database (Denmark)

    Raaf, J; Bischoff, N; Kloppfleisch, K

    2011-01-01

    The protein Ser/Thr kinase CK2 (former name: casein kinase II) exists predominantly as a heterotetrameric holoenzyme composed of two catalytic subunits (CK2α) bound to a dimer of noncatalytic subunits (CK2β). We undertook a study to further understand how these subunits interact to form the tetra......The protein Ser/Thr kinase CK2 (former name: casein kinase II) exists predominantly as a heterotetrameric holoenzyme composed of two catalytic subunits (CK2α) bound to a dimer of noncatalytic subunits (CK2β). We undertook a study to further understand how these subunits interact to form...

  5. The HADES RV Programme with HARPS-N@TNG IV. Time resolved analysis of the Ca ii H&K and H{\\alpha} chromospheric emission of low-activity early-type M dwarfs

    CERN Document Server

    Scandariato, G; Biazzo, K; Leto, G; Stelzer, B; Sanchez, R Zanmar; Claudi, R; Cosentino, R; Damasso, M; Desidera, S; Álvarez, E González; Hernández, J I González; Gratton, R; Lanza, A F; Maggio, A; Messina, S; Micela, G; Pagano, I; Perger, M; Piotto, G; Rebolo, R; Ribas, I; Rosich, A; Sozzetti, A; Mascareño, A Suárez

    2016-01-01

    M dwarfs are prime targets for planet search programs, particularly of those focused on the detection and characterization of rocky planets in the habitable zone. Understanding their magnetic activity is important because it affects our ability to detect small planets, and it plays a key role in the characterization of the stellar environment. We analyze observations of the Ca II H&K and H{\\alpha} lines as diagnostics of chromospheric activity for low-activity early-type M dwarfs. We analyze the time series of spectra of 71 early-type M dwarfs collected for the HADES project for planet search purposes. The HARPS-N spectra provide simultaneously the H&K doublet and the H{\\alpha} line. We develop a reduction scheme able to correct the HARPS-N spectra for instrumental and atmospheric effects, and to provide flux-calibrated spectra in units of flux at the stellar surface. The H&K and H{\\alpha} fluxes are compared with each other, and their variability is analyzed. We find that the H and K flux excesse...

  6. Alpha fetoprotein

    Science.gov (United States)

    Fetal alpha globulin; AFP ... Greater than normal levels of AFP may be due to: Cancer in testes , ovaries, biliary (liver secretion) tract, stomach, or pancreas Cirrhosis of the liver Liver cancer ...

  7. Quantitative and qualitative aspects of topoisomerase I and II alpha and beta in untreated and platinum/cyclophosphamide treated malignant ovarian tumors

    NARCIS (Netherlands)

    van der Zee, A G; de Jong, Steven; Keith, W N; Hollema, H; Boonstra, H; de Vries, Liesbeth

    1994-01-01

    Quantitative and qualitative aspects of topoisomerase (Topo) I and II were studied in 17 malignant ovarian tumors [eight untreated and nine after platinum/cyclophosphamide (Pt/Cy) chemotherapy]. Median Topo II catalytic activity was lower (P <0.05) in tumors after Pt/Cv chemotherapy in comparison to

  8. The progress of pyruvate dehydrogenase E1 alpha subunit in myocardial ischemia-reperfusion injury%丙酮酸脱氢酶E1α亚单位与心肌缺血再灌注损伤的研究进展

    Institute of Scientific and Technical Information of China (English)

    叶星华; 梁贵友

    2016-01-01

    心肌缺血再灌注损伤(MIRI)是临床体外循环(CPB)心脏直视手术术后心功能障碍甚至导致死亡的主要原因之一,其发生机制至今仍未完全阐明.我们的前期研究结果显示,心肌胰岛素抵抗(IR)可能是MIRI的又一重要机制,涉及心肌能量底物葡萄糖和脂肪酸代谢紊乱.近来的研究结果显示,丙酮酸脱氢酶E1α亚单位(PDHA1)作为丙酮酸脱氢酶复合物(PDC)的重要组成部分,在维持缺血缺氧及再灌注心肌细胞糖、脂及能量代谢稳态中扮演关键的角色.通过研究PDHA1的相关分子机制,可进一步阐明体外循环心肌胰岛素抵抗的发生机制,对MIRI的防治具有重要意义.%The myocardial ischemia-reperfusion injury (MIRI) is one of the main reason to cardiac dysfunction which is even leading to the death after a open heart surgery by cardiopulmonary bypass (CPB).However,the mechanism of MIRI remains to be fully elucidated.Our previous studies have shown that myocardial insulin resistance (IR) might be another important mechanism of MIRI,involving myocardial energy substrate glucose and fatty acid metabolism disorders.Recent literatures indicated that pyruvate dehydrogenase E1 component subunit alpha (PDHA1)as the important part of pyruvate dehydrogenase complex (PDC),plays a key role in the maintenance of homeostasis of the carbohydrate,lipid and energy metabolism of ischemia and reperfusion myocardial cells.Through the study on molecular mechanisms of PDHA1,we can further elucidate the mechanism of CPB-myocardial IR and provide an important academic and practical significance forprevention and treatment of MIRI.

  9. The elusive third subunit IIa of the bacterial B-type oxidases: the enzyme from the hyperthermophile Aquifex aeolicus.

    Directory of Open Access Journals (Sweden)

    Laurence Prunetti

    Full Text Available The reduction of molecular oxygen to water is catalyzed by complicated membrane-bound metallo-enzymes containing variable numbers of subunits, called cytochrome c oxidases or quinol oxidases. We previously described the cytochrome c oxidase II from the hyperthermophilic bacterium Aquifex aeolicus as a ba(3-type two-subunit (subunits I and II enzyme and showed that it is included in a supercomplex involved in the sulfide-oxygen respiration pathway. It belongs to the B-family of the heme-copper oxidases, enzymes that are far less studied than the ones from family A. Here, we describe the presence in this enzyme of an additional transmembrane helix "subunit IIa", which is composed of 41 amino acid residues with a measured molecular mass of 5105 Da. Moreover, we show that subunit II, as expected, is in fact longer than the originally annotated protein (from the genome and contains a transmembrane domain. Using Aquifex aeolicus genomic sequence analyses, N-terminal sequencing, peptide mass fingerprinting and mass spectrometry analysis on entire subunits, we conclude that the B-type enzyme from this bacterium is a three-subunit complex. It is composed of subunit I (encoded by coxA(2 of 59000 Da, subunit II (encoded by coxB(2 of 16700 Da and subunit IIa which contain 12, 1 and 1 transmembrane helices respectively. A structural model indicates that the structural organization of the complex strongly resembles that of the ba(3 cytochrome c oxidase from the bacterium Thermus thermophilus, the IIa helical subunit being structurally the lacking N-terminal transmembrane helix of subunit II present in the A-type oxidases. Analysis of the genomic context of genes encoding oxidases indicates that this third subunit is present in many of the bacterial oxidases from B-family, enzymes that have been described as two-subunit complexes.

  10. Comparison of the subunit structure of acetylcholine receptors from muscle and electric organ of Electrophorus electricus.

    Science.gov (United States)

    Gullick, W J; Lindstrom, J M

    1983-08-02

    The acetylcholine receptors of the electric organ and muscle tissues of Electrophorus electricus are composed of alpha, beta, gamma, and delta subunits. Receptor subunits from the two tissues were compared by peptide mapping with monoclonal antibodies, an affinity-labeling reagent, and a lectin to characterize particular peptide fragments. These experiments indicate that the corresponding receptor subunits from the two tissues are extensively homologous or identical throughout their amino acid sequences. Small differences in the electrophoresis of peptide fragments of alpha subunits between the two tissues occurred on fragments which bound labeled lectin. These results suggest that the acetylcholine receptors in electric organ and muscle tissues of Electrophorus differ in structure only by minor posttranslational modifications perhaps involving carbohydrate.

  11. Fibrinogen geneva II: a new congenitally abnormal fibrinogen alpha chain (Gly17Asp) with a review of similar mutations resulting in abnormal knob A.

    Science.gov (United States)

    Casini, Alessandro; De Maistre, Emmanuel; Casini-Stuppi, Virginie; Fontana, Pierre; Neerman-Arbez, Marguerite; de Moerloose, Philippe

    2014-04-01

    Congenital dysfibrinogenemias are characterized by biosynthesis of a structurally abnormal fibrinogen molecule that exhibits reduced functional levels compared with the level of fibrinogen antigen. To date a large number of mutations have been identified in patients with dysfibrinogenemia. Mutations occurring at the thrombin cleavage site (Arg16-Gly17 in the mature alpha-chain) at the amino-terminal end of the fibrinogen alpha chain are a common cause of the disease. These mutations causing abnormal fibrin polymerization are associated with different phenotypes. Here, we report the identification of a novel heterozygous missense mutation of Glycine 17 (Gly17Asp) in a female patient with mild bleeding manifestations, and compare it with other previously reported mutations also resulting in abnormal knob A.

  12. G alpha12 is targeted to the mitochondria and affects mitochondrial morphology and motility.

    Science.gov (United States)

    Andreeva, Alexandra V; Kutuzov, Mikhail A; Voyno-Yasenetskaya, Tatyana A

    2008-08-01

    G alpha12 constitutes, along with G alpha13, one of the four families of alpha subunits of heterotrimeric G proteins. We found that the N terminus of G alpha12, but not those of other G alpha subunits, contains a predicted mitochondrial targeting sequence. Using confocal microscopy and cell fractionation, we demonstrated that up to 40% of endogenous G alpha12 in human umbilical vein endothelial cells colocalize with mitochondrial markers. N-terminal sequence of G alpha12 fused to GFP efficiently targeted the fusion protein to mitochondria. G alpha12 with mutated mitochondrial targeting sequence was still located in mitochondria, suggesting the existence of additional mechanisms for mitochondrial localization. Lysophosphatidic acid, one of the known stimuli transduced by G alpha12/13, inhibited mitochondrial motility, while depletion of endogenous G alpha12 increased mitochondrial motility. G alpha12Q229L variants uncoupled from RhoGEFs (but not fully functional activated G alpha12Q229L) induced transformation of the mitochondrial network into punctate mitochondria and resulted in a loss of mitochondrial membrane potential. All examined G alpha12Q229L variants reduced phosphorylation of Bcl-2 at Ser-70, while only mutants unable to bind RhoGEFs also decreased cellular levels of Bcl-2. These G alpha12 mutants were also more efficient Hsp90 interactors. These findings are the first demonstration of a heterotrimeric G protein alpha subunit specifically targeted to mitochondria and involved in the control of mitochondrial morphology and dynamics.

  13. Structure of 3-oxoacyl-(acyl-carrier protein) synthase II from Thermus thermophilus HB8.

    Science.gov (United States)

    Bagautdinov, Bagautdin; Ukita, Yoko; Miyano, Masashi; Kunishima, Naoki

    2008-05-01

    The beta-ketoacyl-(acyl carrier protein) synthases (beta-keto-ACP synthases; KAS) catalyse the addition of two-carbon units to the growing acyl chain during the elongation phase of fatty-acid synthesis. As key regulators of bacterial fatty-acid synthesis, they are promising targets for the development of new antibacterial agents. The crystal structure of 3-oxoacyl-ACP synthase II from Thermus thermophilus HB8 (TtKAS II) has been solved by molecular replacement and refined at 2.0 A resolution. The crystal is orthorhombic, space group P2(1)2(1)2, with unit-cell parameters a = 72.07, b = 185.57, c = 62.52 A, and contains one homodimer in the asymmetric unit. The subunits adopt the well known alpha-beta-alpha-beta-alpha thiolase fold that is common to ACP synthases. The structural and sequence similarities of TtKAS II to KAS I and KAS II enzymes of known structure from other sources support the hypothesis of comparable enzymatic activity. The dimeric state of TtKAS II is important to create each fatty-acid-binding pocket. Closer examination of KAS structures reveals that compared with other KAS structures in the apo form, the active site of TtKAS II is more accessible because of the ;open' conformation of the Phe396 side chain.

  14. Cloning and Expression of Luteinizing Hormone Subunits in Chinese Hamster Ovary Cell Line

    Directory of Open Access Journals (Sweden)

    Zeinab Soleimanifar

    2016-10-01

    Full Text Available Background: Luteinizing hormone (LH was secreted by the stimulating cells of the testes and ovaries in the anterior pituitary gland. The application of this hormone is in the treatment of men and women with infertility and amenorrhea respectively.Materials and Methods: In the present study the alpha and beta subunits of human LH gene were cloned into the pEGFP-N1 expression vector and produced the recombinant LH hormone in Chinese hamster ovary (CHO eukaryotic system.Results: Alpha and beta subunits of LH hormone were cloned between NheI and BamHI cut sites of pEGFP_N1 expression plasmid and confirmed by PCR.  Hormone expression was evaluated in CHO cell line by Western blotting using the specific antibody.Conclusion: Alpha and beta subunits of LH hormone were expressed in CHO cell line perfectly.

  15. A murine experimental anthracycline extravasation model: pathology and study of the involvement of topoisomerase II alpha and iron in the mechanism of tissue damage

    DEFF Research Database (Denmark)

    Thougaard, Annemette V; Langer, Seppo W; Hainau, Bo;

    2010-01-01

    The bisdioxopiperazine topoisomerase II catalytic inhibitor dexrazoxane has successfully been introduced into the clinic as an antidote to accidental anthracycline extravasation based on our preclinical mouse studies. The histology of this mouse extravasation model was investigated and found...

  16. A novel endogenous antimalarial: Fe(II)-protoporphyrin IX alpha (heme) inhibits hematin polymerization to beta-hematin (malaria pigment) and kills malaria parasites.

    Science.gov (United States)

    Monti, D; Vodopivec, B; Basilico, N; Olliaro, P; Taramelli, D

    1999-07