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Sample records for ancillary pilin subunit

  1. Mutations in the Gene Encoding the Ancillary Pilin Subunit of the Streptococcus suis srtF Cluster Result in Pili Formed by the Major Subunit Only

    Science.gov (United States)

    Fittipaldi, Nahuel; Takamatsu, Daisuke; la Cruz Domínguez-Punaro, María de; Lecours, Marie-Pier; Montpetit, Diane; Osaki, Makoto; Sekizaki, Tsutomu; Gottschalk, Marcelo

    2010-01-01

    Pili have been shown to contribute to the virulence of different Gram-positive pathogenic species. Among other critical steps of bacterial pathogenesis, these structures participate in adherence to host cells, colonization and systemic virulence. Recently, the presence of at least four discrete gene clusters encoding putative pili has been revealed in the major swine pathogen and emerging zoonotic agent Streptococcus suis. However, pili production by this species has not yet been demonstrated. In this study, we investigated the functionality of one of these pili clusters, known as the srtF pilus cluster, by the construction of mutant strains for each of the four genes of the cluster as well as by the generation of antibodies against the putative pilin subunits. Results revealed that the S. suis serotype 2 strain P1/7, as well as several other highly virulent invasive S. suis serotype 2 isolates express pili from this cluster. However, in most cases tested, and as a result of nonsense mutations at the 5′ end of the gene encoding the minor pilin subunit (a putative adhesin), pili were formed by the major pilin subunit only. We then evaluated the role these pili play in S. suis virulence. Abolishment of the expression of srtF cluster-encoded pili did not result in impaired interactions of S. suis with porcine brain microvascular endothelial cells. Furthermore, non-piliated mutants were as virulent as the wild type strain when evaluated in a murine model of S. suis sepsis. Our results show that srtF cluster-encoded, S. suis pili are atypical compared to other Gram-positive pili. In addition, since the highly virulent strains under investigation are unlikely to produce other pili, our results suggest that pili might be dispensable for critical steps of the S. suis pathogenesis of infection. PMID:20052283

  2. Lactobacillus rhamnosus GG SpaC pilin subunit binds to the carbohydrate moieties of intestinal glycoconjugates.

    Science.gov (United States)

    Nishiyama, Keita; Ueno, Shintaro; Sugiyama, Makoto; Yamamoto, Yuji; Mukai, Takao

    2016-06-01

    Lactobacillus rhamnosus GG (LGG) is a well-established probiotic strain. The beneficial properties of this strain are partially dependent on its prolonged residence in the gastrointestinal tract, and are likely influenced by its adhesion to the intestinal mucosa. The pilin SpaC subunit, located within the Spa pili structure, is the most well studied LGG adhesion factor. However, the binding epitopes of SpaC remain largely unknown. The aim of this study was to evaluate the binding properties of SpaC to the carbohydrate moieties of intestinal glycoconjugates using a recombinant SpaC protein. In a competitive enzyme-linked immunosorbent assay, SpaC binding was markedly reduced by addition of purified mucin and the mucin oligosaccharide fraction. Histochemical staining revealed that the binding of SpaC was drastically reduced by periodic acid treatment. Moreover, in the surface plasmon resonance-based Biacore assay, SpaC bound strongly to the carbohydrate moieties containing β-galactoside at the non-reducing terminus of glycolipids. We here provide the first demonstration that SpaC binds to the oligosaccharide chains of mucins, and that the carbohydrate moieties containing β-galactoside at the non-reducing termini of glycoconjugates play a crucial role in this binding. Our results demonstrate the importance of carbohydrates of SpaC for mucus interactions.

  3. Purification, crystallization and preliminary crystallographic analysis of the SpaA backbone-pilin subunit from probiotic Lactobacillus rhamnosus GG.

    Science.gov (United States)

    Singh, Deepak; von Ossowski, Ingemar; Palva, Airi; Krishnan, Vengadesan

    2013-10-01

    Lactobacillus rhamnosus GG, a widely used Gram-positive probiotic strain, is clinically well known for its perceived health-promoting effects. It has recently been shown to display proteinaceous pilus fibres (called SpaCBA) on its cell surface. Structurally, SpaCBA pili possess a characteristic three-pilin polymerized architecture, with repeating SpaA major pilins that form the backbone and two types of minor subunits (SpaB and SpaC). In this study, recombinant SpaA protein was purified, characterized and crystallized. The crystals diffracted to a resolution of 2.0 Å and belonged to space group C2, with unit-cell parameters a=227.9, b=63.2, c=104.3 Å, β=95.1°.

  4. Crystallization and X-ray Crystallographic Analysis of the Adhesive SpaC Pilin Subunit in the SpaCBA Pilus of Gut-adapted Lactobacillus rhamnosus GG.

    Science.gov (United States)

    Kant, Abhiruchi; von Ossowski, Ingemar; Palva, Airi; Krishnan, Vengadesan

    2016-01-01

    Gram-positive Lactobacillus rhamnosus GG, a gut-adapted commensalic (and probiotic) strain, is known to express sortase-assembled pili on its cell surface. These SpaCBA-called pili consist of three different types of building blocks; the SpaA backbone-pilin subunit and the SpaB and SpaC ancillary pilins. SpaC is a relatively large (~90kDa) multi-domain fimbrial adhesin, and while it is located primarily at the SpaCBA pilus tip, occasionally, it can also be detected throughout the length of pilus backbone. Functionally, SpaC mainly accounts for SpaCBA pilus-mediated interactions with intestinal mucus, collagen, and human gut epithelial cells. Moreover, SpaC adhesiveness is also perceived to have a causal relationship with SpaCBA pilus-induced host-cell immune responses. In order to improve the mechanistic understanding of SpaC and its adhesive properties by structural investigation, we purified and successfully crystallized a recombinant construct of the near full-length SpaC protein (residues 36-856) in the presence of magnesium ions. X-ray diffraction data were collected to 2.6 Å resolution. The SpaC crystal belongs to the space group P21212 with unit cell parameters a = 116.5, b = 128.3, c = 136.5 Å and contains two molecules in the asymmetric unit. Presence of conserved metal ion-dependent adhesion site containing von Willebrand factor type A domain suggests its likely role in the function of SpaC.

  5. Phylogeny, clinical associations, and diagnostic utility of the pilin subunit gene (sfpA) of sorbitol-fermenting, enterohemorrhagic Escherichia coli O157:H-

    NARCIS (Netherlands)

    Friedrich, Alexander W; Nierhoff, Katja V; Bielaszewska, Martina; Mellmann, Alexander; Karch, Helge

    2004-01-01

    The plasmid-borne sfpA gene encodes the pilin subunit in sorbitol-fermenting (SF) enterohemorrhagic Escherichia coli (EHEC) O157:H-. We investigated the distribution of sfpA among 600 E. coli isolates comprising the complete E. coli standard reference (ECOR) and diarrheagenic E. coli (DEC) strain co

  6. Pilin Processing Follows a Different Temporal Route than That of Archaellins in Methanococcus maripaludis

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    Divya B. Nair

    2015-01-01

    Full Text Available Methanococcus maripaludis has two different surface appendages: type IV-like pili and archaella. Both structures are believed to be assembled using a bacterial type IV pilus mechanism. Each structure is composed of multiple subunits, either pilins or archaellins. Both pilins and archaellins are made initially as preproteins with type IV pilin-like signal peptides, which must be removed by a prepilin peptidase-like enzyme. This enzyme is FlaK for archaellins and EppA for pilins. In addition, both pilins and archaellins are modified with N-linked glycans. The archaellins possess an N-linked tetrasaccharide while the pilins have a pentasaccharide which consists of the archaellin tetrasaccharide but with an additional sugar, an unidentified hexose, attached to the linking sugar. In this report, we show that archaellins can be processed by FlaK in the absence of N-glycosylation and N-glycosylation can occur on archaellins that still retain their signal peptides. In contrast, pilins are not glycosylated unless they have been acted on by EppA to have the signal peptide removed. However, EppA can still remove signal peptides from non-glycosylated pilins. These findings indicate that there is a difference in the order of the posttranslational modifications of pilins and archaellins even though both are type IV pilin-like proteins.

  7. Pilin Processing Follows a Different Temporal Route than That of Archaellins in Methanococcus maripaludis

    Science.gov (United States)

    Nair, Divya B.; Jarrell, Ken F.

    2015-01-01

    Methanococcus maripaludis has two different surface appendages: type IV-like pili and archaella. Both structures are believed to be assembled using a bacterial type IV pilus mechanism. Each structure is composed of multiple subunits, either pilins or archaellins. Both pilins and archaellins are made initially as preproteins with type IV pilin-like signal peptides, which must be removed by a prepilin peptidase-like enzyme. This enzyme is FlaK for archaellins and EppA for pilins. In addition, both pilins and archaellins are modified with N-linked glycans. The archaellins possess an N-linked tetrasaccharide while the pilins have a pentasaccharide which consists of the archaellin tetrasaccharide but with an additional sugar, an unidentified hexose, attached to the linking sugar. In this report, we show that archaellins can be processed by FlaK in the absence of N-glycosylation and N-glycosylation can occur on archaellins that still retain their signal peptides. In contrast, pilins are not glycosylated unless they have been acted on by EppA to have the signal peptide removed. However, EppA can still remove signal peptides from non-glycosylated pilins. These findings indicate that there is a difference in the order of the posttranslational modifications of pilins and archaellins even though both are type IV pilin-like proteins. PMID:25569238

  8. Intron retention in mRNA encoding ancillary subunit of insect voltage-gated sodium channel modulates channel expression, gating regulation and drug sensitivity.

    Science.gov (United States)

    Bourdin, Céline M; Moignot, Bénédicte; Wang, Lingxin; Murillo, Laurence; Juchaux, Marjorie; Quinchard, Sophie; Lapied, Bruno; Guérineau, Nathalie C; Dong, Ke; Legros, Christian

    2013-01-01

    Insect voltage-gated sodium (Nav) channels are formed by a well-known pore-forming α-subunit encoded by para-like gene and ancillary subunits related to TipE from the mutation "temperature-induced-paralysis locus E." The role of these ancillary subunits in the modulation of biophysical and pharmacological properties of Na(+) currents are not enough documented. The unique neuronal ancillary subunit TipE-homologous protein 1 of Drosophila melanogaster (DmTEH1) strongly enhances the expression of insect Nav channels when heterologously expressed in Xenopus oocytes. Here we report the cloning and functional expression of two neuronal DmTEH1-homologs of the cockroach, Periplaneta americana, PaTEH1A and PaTEH1B, encoded by a single bicistronic gene. In PaTEH1B, the second exon encoding the last 11-amino-acid residues of PaTEH1A is shifted to 3'UTR by the retention of a 96-bp intron-containing coding-message, thus generating a new C-terminal end. We investigated the gating and pharmacological properties of the Drosophila Nav channel variant (DmNav1-1) co-expressed with DmTEH1, PaTEH1A, PaTEH1B or a truncated mutant PaTEH1Δ(270-280) in Xenopus oocytes. PaTEH1B caused a 2.2-fold current density decrease, concomitant with an equivalent α-subunit incorporation decrease in the plasma membrane, compared to PaTEH1A and PaTEH1Δ(270-280). PaTEH1B positively shifted the voltage-dependences of activation and slow inactivation of DmNav1-1 channels to more positive potentials compared to PaTEH1A, suggesting that the C-terminal end of both proteins may influence the function of the voltage-sensor and the pore of Nav channel. Interestingly, our findings showed that the sensitivity of DmNav1-1 channels to lidocaine and to the pyrazoline-type insecticide metabolite DCJW depends on associated TEH1-like subunits. In conclusion, our work demonstrates for the first time that density, gating and pharmacological properties of Nav channels expressed in Xenopus oocytes can be modulated by an

  9. Structural Characterization of Novel Pseudomonas aeruginosa Type IV Pilins

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Y.; Jackson, S; Aidoo, F; Junop, M; Burrows, L

    2010-01-01

    Pseudomonas aeruginosa type IV pili, composed of PilA subunits, are used for attachment and twitching motility on surfaces. P. aeruginosa strains express one of five phylogenetically distinct PilA proteins, four of which are associated with accessory proteins that are involved either in pilin posttranslational modification or in modulation of pilus retraction dynamics. Full understanding of pilin diversity is crucial for the development of a broadly protective pilus-based vaccine. Here, we report the 1.6-{angstrom} X-ray crystal structure of an N-terminally truncated form of the novel PilA from strain Pa110594 (group V), which represents the first non-group II pilin structure solved. Although it maintains the typical T4a pilin fold, with a long N-terminal {alpha}-helix and four-stranded antiparallel {beta}-sheet connected to the C-terminus by a disulfide-bonded loop, the presence of an extra helix in the {alpha}{beta}-loop and a disulfide-bonded loop with helical character gives the structure T4b pilin characteristics. Despite the presence of T4b features, the structure of PilA from strain Pa110594 is most similar to the Neisseria gonorrhoeae pilin and is also predicted to assemble into a fiber similar to the GC pilus, based on our comparative pilus modeling. Interactions between surface-exposed areas of the pilin are suggested to contribute to pilus fiber stability. The non-synonymous sequence changes between group III and V pilins are clustered in the same surface-exposed areas, possibly having an effect on accessory protein interactions. However, based on our high-confidence model of group III PilA{sub PA14}, compensatory changes allow for maintenance of a similar shape.

  10. Purification, crystallization and preliminary X-ray diffraction analysis of SpaD, a backbone-pilin subunit encoded by the fimbrial spaFED operon in Lactobacillus rhamnosus GG.

    Science.gov (United States)

    Chaurasia, Priyanka; von Ossowski, Ingemar; Palva, Airi; Krishnan, Vengadesan

    2015-01-01

    SpaD is the predicted backbone-pilin subunit of the SpaFED pilus, whose loci are encoded by the fimbrial spaFED operon in Lactobacillus rhamnosus GG, a Gram-positive gut-adapted commensal strain with perceived probiotic benefits. In this study, soluble recombinant SpaD protein was overproduced in Escherichia coli and then purified by Ni2+-chelating affinity and gel-filtration chromatography. After limited proteolysis with α-chymotrypsin, good-quality crystals of SpaD were obtained which diffracted beyond 2.0 Å resolution. These crystals belonged to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a=50.11, b=83.27, c=149.65 Å. For phasing, sodium iodide-derivatized crystals were prepared using the halide quick-soaking method and diffraction data were collected in-house to a resolution of 2.2 Å. An interpretable electron-density map was successfully obtained using single-wavelength anomalous diffraction (SAD).

  11. Crystallization and preliminary X-ray diffraction analysis of PsaA, the adhesive pilin subunit that forms the pH 6 antigen on the surface of Yersinia pestis.

    Science.gov (United States)

    Bao, Rui; Esser, Lothar; Sadhukhan, Annapurna; Nair, Manoj K M; Schifferli, Dieter M; Xia, Di

    2012-10-01

    Yersinia pestis has been responsible for a number of high-mortality epidemics throughout human history. Like all other bacterial infections, the pathogenesis of Y. pestis begins with the attachment of bacteria to the surface of host cells. At least five surface proteins from Y. pestis have been shown to interact with host cells. Psa, the pH 6 antigen, is one of them and is deployed on the surface of bacteria as thin flexible fibrils that are the result of the polymerization of a single PsaA pilin subunit. Here, the crystallization of recombinant donor-strand complemented PsaA by the hanging-drop vapor-diffusion method is reported. X-ray diffraction data sets were collected to 1.9 Å resolution from a native crystal and to 1.5 Å resolution from a bromide-derivatized crystal. These crystals displayed the symmetry of the orthorhombic space group P222(1), with unit-cell parameters a = 26.3, b = 54.6, c = 102.1 Å. Initial phases were derived from single isomorphous replacement with anomalous scattering experiments, resulting in an electron-density map that showed a single molecule in the crystallographic asymmetric unit. Sequence assignment was aided by residues binding to bromide ions of the heavy-atom derivative.

  12. Novel archaeal adhesion pilins with a conserved N terminus.

    Science.gov (United States)

    Esquivel, Rianne N; Xu, Rachel; Pohlschroder, Mechthild

    2013-09-01

    Type IV pili play important roles in a wide array of processes, including surface adhesion and twitching motility. Although archaeal genomes encode a diverse set of type IV pilus subunits, the functions for most remain unknown. We have now characterized six Haloferax volcanii pilins, PilA[1-6], each containing an identical 30-amino-acid N-terminal hydrophobic motif that is part of a larger highly conserved domain of unknown function (Duf1628). Deletion mutants lacking up to five of the six pilin genes display no significant adhesion defects; however, H. volcanii lacking all six pilins (ΔpilA[1-6]) does not adhere to glass or plastic. Consistent with these results, the expression of any one of these pilins in trans is sufficient to produce functional pili in the ΔpilA[1-6] strain. PilA1His and PilA2His only partially rescue this phenotype, whereas ΔpilA[1-6] strains expressing PilA3His or PilA4His adhere even more strongly than the parental strain. Most surprisingly, expressing either PilA5His or PilA6His in the ΔpilA[1-6] strain results in microcolony formation. A hybrid protein in which the conserved N terminus of the mature PilA1His is replaced with the corresponding N domain of FlgA1 is processed by the prepilin peptidase, but it does not assemble functional pili, leading us to conclude that Duf1628 can be annotated as the N terminus of archaeal PilA adhesion pilins. Finally, the pilin prediction program, FlaFind, which was trained primarily on archaeal flagellin sequences, was successfully refined to more accurately predict pilins based on the in vivo verification of PilA[1-6].

  13. Structural and functional studies of the Pseudomonas aeruginosa minor pilin, PilE.

    Science.gov (United States)

    Nguyen, Ylan; Harvey, Hanjeong; Sugiman-Marangos, Seiji; Bell, Stephanie D; Buensuceso, Ryan N C; Junop, Murray S; Burrows, Lori L

    2015-10-30

    Many bacterial pathogens, including Pseudomonas aeruginosa, use type IVa pili (T4aP) for attachment and twitching motility. T4aP are composed primarily of major pilin subunits, which are repeatedly assembled and disassembled to mediate function. A group of pilin-like proteins, the minor pilins FimU and PilVWXE, prime pilus assembly and are incorporated into the pilus. We showed previously that minor pilin PilE depends on the putative priming subcomplex PilVWX and the non-pilin protein PilY1 for incorporation into pili, and that with FimU, PilE may couple the priming subcomplex to the major pilin PilA, allowing for efficient pilus assembly. Here we provide further support for this model, showing interaction of PilE with other minor pilins and the major pilin. A 1.25 Å crystal structure of PilEΔ1-28 shows a typical type IV pilin fold, demonstrating how it may be incorporated into the pilus. Despite limited sequence identity, PilE is structurally similar to Neisseria meningitidis minor pilins PilXNm and PilVNm, recently suggested via characterization of mCherry fusions to modulate pilus assembly from within the periplasm. A P. aeruginosa PilE-mCherry fusion failed to complement twitching motility or piliation of a pilE mutant. However, in a retraction-deficient strain where surface piliation depends solely on PilE, the fusion construct restored some surface piliation. PilE-mCherry was present in sheared surface fractions, suggesting that it was incorporated into pili. Together, these data provide evidence that PilE, the sole P. aeruginosa equivalent of PilXNm and PilVNm, likely connects a priming subcomplex to the major pilin, promoting efficient assembly of T4aP.

  14. Comparative analysis of Haemophilus influenzae hifA (pilin) genes.

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    Clemans, D L; Marrs, C F; Patel, M; Duncan, M; Gilsdorf, J R

    1998-02-01

    Adherence of Haemophilus influenzae to epithelial cells plays a central role in colonization and is the first step in infection with this organism. Pili, which are large polymorphic surface proteins, have been shown to mediate the binding of H. influenzae to cells of the human respiratory tract. Earlier experiments have demonstrated that the major epitopes of H. influenzae pili are highly conformational and immunologically heterogenous; their subunit pilins are, however, immunologically homogenous. To define the extent of structural variation in pilins, which polymerize to form pili, the pilin genes (hifA) of 26 type a to f and 16 nontypeable strains of H. influenzae were amplified by PCR and subjected to restriction fragment length polymorphism (RFLP) analysis with AluI and RsaI. Six different RFLP patterns were identified. Four further RFLP patterns were identified from published hifA sequences from five nontypeable H. influenzae strains. Two patterns contained only nontypeable isolates; one of these contained H. influenzae biotype aegyptius strains F3031 and F3037. Another pattern contained predominantly H. influenzae type f strains. All other patterns were displayed by a variety of capsular and noncapsular types. Sequence analysis of selected hifA genes confirmed the 10 RFLP patterns and showed strong identity among representatives displaying the same RFLP patterns. In addition, the immunologic reactivity of pili with antipilus antisera correlated with the groupings of strains based on hifA RFLP patterns. Those strains that show greater reactivity with antiserum directed against H. influenzae type b strain M43 pili tend to fall into one RFLP pattern (pattern 3); while those strains that show equal or greater reactivity with antiserum directed against H. influenzae type b strain Eagan pili tend to fall in a different RFLP pattern (pattern 1). Sequence analysis of representative HifA pilins from typeable and nontypeable H. influenzae identified several highly

  15. The type 4 pilin of Moraxella nonliquefaciens exhibits unique similarities with the pilins of Neisseria gonorrhoeae and Dichelobacter (Bacteroides) nodosus.

    Science.gov (United States)

    Tønjum, T; Marrs, C F; Rozsa, F; Bøvre, K

    1991-10-01

    Moraxella nonliquefaciens is a bacterium which is part of the normal flora of the human upper respiratory tract and is an occasional cause of disease. Using a previously cloned type 4 pilin gene (tfpQ) from Moraxella bovis as a hybridization probe, we have cloned an 826 bp Sau3 AI fragment which contains an M. nonliquefaciens type 4 pilin gene (tfpA) from strain NCTC 7784. The pilin gene is expressed in Escherichia coli. We have examined NCTC 7784 and nine other M. nonliquefaciens strains by genomic Southern hybridization using tfpA as a probe, and they all appeared to have more than one pilin gene. While the predicted amino acid sequence of the M. nonliquefaciens tfpA pilin has conserved regions as compared to pilins of M. bovis and M. lacunata, it also shows similarities to both the type 4 pilin of Neisseria gonorrhoeae and the type 4 pilin of Dichelobacter nodosus (formerly Bacteroides nodosus).

  16. Comparative Analysis of Type IV Pilin in Desulfuromonadales

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    Shu, Chuanjun; Xiao, Ke; Yan, Qin; Sun, Xiao

    2016-01-01

    During anaerobic respiration, the bacteria Geobacter sulfurreducens can transfer electrons to extracellular electron accepters through its pilus. G. sulfurreducens pili have been reported to have metallic-like conductivity that is similar to doped organic semiconductors. To study the characteristics and origin of conductive pilin proteins found in the pilus structure, their genetic, structural, and phylogenetic properties were analyzed. The genetic relationships, and conserved structures and sequences that were obtained were used to predict the evolution of the pilins. Homologous genes that encode conductive pilin were found using PilFind and Cluster. Sequence characteristics and protein tertiary structures were analyzed with MAFFT and QUARK, respectively. The origin of conductive pilins was explored by building a phylogenetic tree. Truncation is a characteristic of conductive pilin. The structures of truncated pilins and their accompanying proteins were found to be similar to the N-terminal and C-terminal ends of full-length pilins respectively. The emergence of the truncated pilins can probably be ascribed to the evolutionary pressure of their extracellular electron transporting function. Genes encoding truncated pilins and proteins similar to the C-terminal of full-length pilins, which contain a group of consecutive anti-parallel beta-sheets, are adjacent in bacterial genomes. According to the genetic, structure, and phylogenetic analyses performed in this study, we inferred that the truncated pilins and their accompanying proteins probably evolved from full-length pilins by gene fission through duplication, degeneration, and separation. These findings provide new insights about the molecular mechanisms involved in long-range electron transport along the conductive pili of Geobacter species. PMID:28066394

  17. Structure of the type IVa major pilin from the electrically conductive bacterial nanowires of Geobacter sulfurreducens.

    Science.gov (United States)

    Reardon, Patrick N; Mueller, Karl T

    2013-10-11

    Several species of δ proteobacteria are capable of reducing insoluble metal oxides as well as other extracellular electron acceptors. These bacteria play a critical role in the cycling of minerals in subsurface environments, sediments, and groundwater. In some species of bacteria such as Geobacter sulfurreducens, the transport of electrons is proposed to be facilitated by filamentous fibers that are referred to as bacterial nanowires. These nanowires are polymeric assemblies of proteins belonging to the type IVa family of pilin proteins and are mainly comprised of one subunit protein, PilA. Here, we report the high resolution solution NMR structure of the PilA protein from G. sulfurreducens determined in detergent micelles. The protein is >85% α-helical and exhibits similar architecture to the N-terminal regions of other non-conductive type IVa pilins. The detergent micelle interacts with the first 21 amino acids of the protein, indicating that this region likely associates with the bacterial inner membrane prior to fiber formation. A model of the G. sulfurreducens pilus fiber is proposed based on docking of this structure into the fiber model of the type IVa pilin from Neisseria gonorrhoeae. This model provides insight into the organization of aromatic amino acids that are important for electrical conduction.

  18. Structure of the Type IVa Major Pilin from the Electrically Conductive Bacterial Nanowires of Geobacter sulfurreducens

    Energy Technology Data Exchange (ETDEWEB)

    Reardon, Patrick N.; Mueller, Karl T.

    2013-10-11

    Several species of bacteria are capable of reducing insoluble metal oxides as well as other extracellular electron acceptors. These bacteria play a critical role in the cycling of minerals in subsurface environments, sediments, and groundwater. In some species of bacteria, such as Geobacter sulfurreducens, the transport of electrons is facilitated by filamentous fibers that are referred to as bacterial nanowires. These nanowires belong to the type IVa family of pilin proteins and are mainly comprised of one subunit protein, PilA. Here, we report the high resolution solution nuclear magnetic resonance (NMR) structure of the PilA protein from G. sulfurreducens determined in detergent micelles. The protein is over 85% α-helical and exhibits similar architecture to the N-terminal regions of other non-conductive type IVa pilins. The detergent micelle interacts with the first 21 amino acids of the protein, indicating that this region likely associates with the bacterial inner membrane prior to fiber formation. A model of the G. sulfurreducens pilus fiber is proposed based on docking of this structure into the fiber model of the type IVa pilin from Neisseria gonorrhoeae. This model provides insight into the organization of aromatic amino acids that are important for electrical conduction.

  19. Cloning and sequencing of a Moraxella bovis pilin gene.

    OpenAIRE

    1985-01-01

    Moraxella bovis pili have been shown to play a major role in both infectivity and protective immunity of bovine infectious keratoconjunctivitis. Sonicated M. bovis DNA from the piliated strain EPP63 was inserted into the vector lambda gt11 with EcoRI linkers. Recombinant phage were screened with an oligonucleotide probe based on the amino-terminal portion of the DNA sequence of a Neisseria gonorrhoeae pilin gene. Two candidate phages produced a protein that comigrated with EPP63 beta pilin in...

  20. Cloning and sequencing of a Moraxella bovis pilin gene.

    Science.gov (United States)

    Marrs, C F; Schoolnik, G; Koomey, J M; Hardy, J; Rothbard, J; Falkow, S

    1985-07-01

    Moraxella bovis pili have been shown to play a major role in both infectivity and protective immunity of bovine infectious keratoconjunctivitis. Sonicated M. bovis DNA from the piliated strain EPP63 was inserted into the vector lambda gt11 with EcoRI linkers. Recombinant phage were screened with an oligonucleotide probe based on the amino-terminal portion of the DNA sequence of a Neisseria gonorrhoeae pilin gene. Two candidate phages produced a protein that comigrated with EPP63 beta pilin in sodium dodecyl sulfate-polyacrylamide gels and bound anti-pilus antisera. The 1.9-kilobase insert from one of these, lambda gt11M182, was subcloned in both orientations into pBR322, forming the plasmids pMxB7 and pMxB9, both of which produced beta pilin, as did pMxB12, a HindIII deletion derivative of pMxB7. In HB101(pMxB12), the M. bovis pilin protein was shown to be primarily localized in the inner membrane. The entire 939-base-pair insert of pMxB12 was sequenced, revealing a ribosome binding site just upstream of the coding region and an AT-rich region further upstream containing some potential RNA polymerase recognition sites. The translation of the sequence predicts a six-amino-acid leader sequence preceding the phenylalanine that begins the mature protein. Codon usage analysis of the M. bovis beta pilin gene revealed greater use of the CUA codon for leucine than usual for a well-expressed Escherichia coli gene. Comparisons of the M. bovis EPP63 beta pilin protein sequence with other pilin gene sequences are presented.

  1. The Vibrio cholerae Minor Pilin TcpB Initiates Assembly and Retraction of the Toxin-Coregulated Pilus

    Science.gov (United States)

    Harn, Tony; Spielman, Ingrid; Gao, Yang; Kovacikova, Gabriela; Biais, Nicolas

    2016-01-01

    Type IV pilus (T4P) systems are complex molecular machines that polymerize major pilin proteins into thin filaments displayed on bacterial surfaces. Pilus functions require rapid extension and depolymerization of the pilus, powered by the assembly and retraction ATPases, respectively. A set of low abundance minor pilins influences pilus dynamics by unknown mechanisms. The Vibrio cholerae toxin-coregulated pilus (TCP) is among the simplest of the T4P systems, having a single minor pilin TcpB and lacking a retraction ATPase. Here we show that TcpB, like its homolog CofB, initiates pilus assembly. TcpB co-localizes with the pili but at extremely low levels, equivalent to one subunit per pilus. We used a micropillars assay to demonstrate that TCP are retractile despite the absence of a retraction ATPase, and that retraction relies on TcpB, as a V. cholerae tcpB Glu5Val mutant is fully piliated but does not induce micropillars movements. This mutant is impaired in TCP-mediated autoagglutination and TcpF secretion, consistent with retraction being required for these functions. We propose that TcpB initiates pilus retraction by incorporating into the growing pilus in a Glu5-dependent manner, which stalls assembly and triggers processive disassembly. These results provide a framework for understanding filament dynamics in more complex T4P systems and the closely related Type II secretion system. PMID:27992883

  2. Characterization of pilin genes from seven serologically defined prototype strains of Moraxella bovis.

    Science.gov (United States)

    Atwell, J L; Tennent, J M; Lepper, A W; Elleman, T C

    1994-08-01

    Numerous field isolates of Moraxella bovis have previously been classified by serological techniques into seven serogroups, each defined by homologous cross-reaction with antisera prepared against purified pili of a single prototype strain. The gene encoding pilin from each of the prototype strains has been characterized by nucleotide sequence determination. The coding sequences show extensive homology (70 to 80%) while the proximal downstream sequences show a dichotomy into nonhomologous sets. The pilin genes of three more strains were also characterized. The presence of an additional, partial pilin gene in each prototype strain was confirmed by Southern blot analysis, and the partial pilin genes from two strains of one serogroup were characterized by sequence determination. Features of the pilin gene sequences are considered in relation to pilin gene inversion and the serological variants of strains which may arise from gene inversion events.

  3. Isopeptide bonds of the major pilin protein BcpA influence pilus structure and bundle formation on the surface of Bacillus cereus

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickx, Antoni P.A.; Poor, Catherine B.; Jureller, Justin E.; Budzik, Jonathan M.; He, Chuan; Schneewind, Olaf (UC)

    2012-09-05

    Bacillus cereus strains elaborate pili on their surface using a mechanism of sortase-mediated cross-linking of major and minor pilus components. Here we used a combination of electron microscopy and atomic force microscopy to visualize these structures. Pili occur as single, double or higher order assemblies of filaments formed from monomers of the major pilin, BcpA, capped by the minor pilin, BcpB. Previous studies demonstrated that within assembled pili, four domains of BcpA -- CNA{sub 1}, CNA{sub 2}, XNA and CNA{sub 3} -- each acquire intramolecular lysine-asparagine isopeptide bonds formed via catalytic glutamic acid or aspartic acid residues. Here we showed that mutants unable to form the intramolecular isopeptide bonds in the CNA2 or CNA3 domains retain the ability to form pilus bundles. A mutant lacking the CNA{sub 1} isopeptide bond assembled deformed pilin subunits that failed to associate as bundles. X-ray crystallography revealed that the BcpA variant Asp{sup 312}Ala, lacking an aspartyl catalyst, did not generate the isopeptide bond within the jelly-roll structure of XNA. The Asp{sup 312}Ala mutant was also unable to form bundles and promoted the assembly of deformed pili. Thus, structural integrity of the CNA{sub 1} and XNA domains are determinants for the association of pili into higher order bundle structures and determine native pilus structure.

  4. A slow-forming isopeptide bond in the structure of the major pilin SpaD from Corynebacterium diphtheriae has implications for pilus assembly

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hae Joo; Paterson, Neil G. [University of Auckland, Private Bag 92019, Auckland 1142 (New Zealand); Kim, Chae Un [Cornell University, Ithaca, NY 14853 (United States); Middleditch, Martin [University of Auckland, Private Bag 92019, Auckland 1142 (New Zealand); Chang, Chungyu; Ton-That, Hung [University of Texas–Houston Medical School, Houston, TX 77030 (United States); Baker, Edward N., E-mail: ted.baker@auckland.ac.nz [University of Auckland, Private Bag 92019, Auckland 1142 (New Zealand)

    2014-05-01

    Two crystal structures of the major pilin SpaD from C. diphtheriae have been determined at 1.87 and 2.5 Å resolution. The N-terminal domain is found to contain an isopeptide bond that forms slowly over time in the recombinant protein. Given its structural context, this provides insight into the relationship between internal isopeptide-bond formation and pilus assembly. The Gram-positive organism Corynebacterium diphtheriae, the cause of diphtheria in humans, expresses pili on its surface which it uses for adhesion and colonization of its host. These pili are covalent protein polymers composed of three types of pilin subunit that are assembled by specific sortase enzymes. A structural analysis of the major pilin SpaD, which forms the polymeric backbone of one of the three types of pilus expressed by C. diphtheriae, is reported. Mass-spectral and crystallographic analysis shows that SpaD contains three internal Lys–Asn isopeptide bonds. One of these, shown by mass spectrometry to be located in the N-terminal D1 domain of the protein, only forms slowly, implying an energy barrier to bond formation. Two crystal structures, of the full-length three-domain protein at 2.5 Å resolution and of a two-domain (D2-D3) construct at 1.87 Å resolution, show that each of the three Ig-like domains contains a single Lys–Asn isopeptide-bond cross-link, assumed to give mechanical stability as in other such pili. Additional stabilizing features include a disulfide bond in the D3 domain and a calcium-binding loop in D2. The N-terminal D1 domain is more flexible than the others and, by analogy with other major pilins of this type, the slow formation of its isopeptide bond can be attributed to its location adjacent to the lysine used in sortase-mediated polymerization during pilus assembly.

  5. Sequence divergence in two tandemly located pilin genes of Eikenella corrodens.

    Science.gov (United States)

    Tønjum, T; Weir, S; Bøvre, K; Progulske-Fox, A; Marrs, C F

    1993-05-01

    Eikenella corrodens normally inhabits the human respiratory and gastrointestinal tracts but is frequently the cause of abscesses at various sites. Using the N-terminal portion of the Moraxella nonliquefaciens pilin gene as a hybridization probe, we cloned two tandemly located pilin genes of E. corrodens 31745, ecpC and ecpD, and expressed the two pilin genes separately in Escherichia coli. A comparison of the predicted amino acid sequences of E. corrodens 31745 EcpC and EcpD revealed considerable divergence between the sequences of these two pilins and even less similarity to EcpA and EcpB of E. corrodens type strain ATCC 23834. EcpC from E. corrodens 31745 displayed high degrees of homology to the pilins of Neisseria gonorrhoeae and Pseudomonas aeruginosa. EcpD from E. corrodens 31745 showed the highest homologies with the pilin of one of the three P. aeruginosa classes, whereas EcpA and EcpB of strain ATCC 23834 most closely resemble Moraxella bovis pilins. These findings raise interesting questions about potential genetic transfer between different bacterial species, as opposed to convergent evolution.

  6. Sequence divergence in two tandemly located pilin genes of Eikenella corrodens.

    OpenAIRE

    1993-01-01

    Eikenella corrodens normally inhabits the human respiratory and gastrointestinal tracts but is frequently the cause of abscesses at various sites. Using the N-terminal portion of the Moraxella nonliquefaciens pilin gene as a hybridization probe, we cloned two tandemly located pilin genes of E. corrodens 31745, ecpC and ecpD, and expressed the two pilin genes separately in Escherichia coli. A comparison of the predicted amino acid sequences of E. corrodens 31745 EcpC and EcpD revealed consider...

  7. Ancillary testing in brain death.

    Science.gov (United States)

    Kramer, Andreas H

    2015-04-01

    Despite worldwide acceptance of the concept of brain death, there is marked variability in the use of ancillary testing. In most countries, ancillary tests are used primarily when confounding factors interfere with reliable completion of a clinical assessment, or physiologic instability precludes performance of an apnea test. Alternatively, in some countries, confirmatory ancillary tests are routinely required before brain death can be diagnosed. Ancillary tests assess brain function (e.g., electroencephalography) or blood flow (e.g., cerebral angiography). Evaluation of blood flow is affected less by confounding clinical factors and is now preferred in most jurisdictions. With angiographic techniques, a significant proportion of patients meeting clinical criteria for brain death have some opacification of proximal intracranial arteries. Consequently, the sensitivity of angiography is strongly influenced by the particular criteria that are used to define intracranial circulatory arrest. Lack of enhancement of the great cerebral and internal cerebral veins has the highest sensitivity. Worldwide experience with newer tests, such as computed tomography and magnetic resonance angiography, is growing. Radionuclide imaging has the advantage of not requiring use of potentially nephrotoxic contrast material. Transcranial Doppler ultrasonography can be brought to the bedside to demonstrate lack of brain blood flow. The specificity of imaging techniques in the detection of intracranial circulatory arrest has not been as well studied as their sensitivity.

  8. Cloning and sequence analysis of the structural pilin gene of Brazilian purpuric fever-associated Haemophilus influenzae biogroup aegyptius.

    Science.gov (United States)

    Whitney, A M; Farley, M M

    1993-04-01

    We have cloned and sequenced the Brazilian purpuric fever (BPF)-associated Haemophilus influenzae biogroup aegyptius (Hae) pilin gene. The sequence contained a 648-bp open reading frame encoding a mature pilin protein of 191 amino acids with a calculated mass of 20.5 kDa. There was 82% homology between the open reading frames of the BPF strain F3031 and H. influenzae type b (Hib) (strain M43) pilin genes and 71% homology at the amino acid level between the mature pilin proteins. However, areas of diversity were noted throughout the gene. A 17-bp probe corresponding to an area of diversity in the N-terminal region of the BPF-associated gene hybridized with other BPF strains but not with non-BPF Hae or Hib. In summary, the pilin protein of BPF-associated Hae is highly homologous to Hib pilin yet remains structurally distinct.

  9. A slow-forming isopeptide bond in the structure of the major pilin SpaD from Corynebacterium diphtheriae has implications for pilus assembly.

    Science.gov (United States)

    Kang, Hae Joo; Paterson, Neil G; Kim, Chae Un; Middleditch, Martin; Chang, Chungyu; Ton-That, Hung; Baker, Edward N

    2014-05-01

    The Gram-positive organism Corynebacterium diphtheriae, the cause of diphtheria in humans, expresses pili on its surface which it uses for adhesion and colonization of its host. These pili are covalent protein polymers composed of three types of pilin subunit that are assembled by specific sortase enzymes. A structural analysis of the major pilin SpaD, which forms the polymeric backbone of one of the three types of pilus expressed by C. diphtheriae, is reported. Mass-spectral and crystallographic analysis shows that SpaD contains three internal Lys-Asn isopeptide bonds. One of these, shown by mass spectrometry to be located in the N-terminal D1 domain of the protein, only forms slowly, implying an energy barrier to bond formation. Two crystal structures, of the full-length three-domain protein at 2.5 Å resolution and of a two-domain (D2-D3) construct at 1.87 Å resolution, show that each of the three Ig-like domains contains a single Lys-Asn isopeptide-bond cross-link, assumed to give mechanical stability as in other such pili. Additional stabilizing features include a disulfide bond in the D3 domain and a calcium-binding loop in D2. The N-terminal D1 domain is more flexible than the others and, by analogy with other major pilins of this type, the slow formation of its isopeptide bond can be attributed to its location adjacent to the lysine used in sortase-mediated polymerization during pilus assembly.

  10. Ancillary Services Provided from DER

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, J.B.

    2005-12-21

    Distributed energy resources (DER) are quickly making their way to industry primarily as backup generation. They are effective at starting and then producing full-load power within a few seconds. The distribution system is aging and transmission system development has not kept up with the growth in load and generation. The nation's transmission system is stressed with heavy power flows over long distances, and many areas are experiencing problems in providing the power quality needed to satisfy customers. Thus, a new market for DER is beginning to emerge. DER can alleviate the burden on the distribution system by providing ancillary services while providing a cost adjustment for the DER owner. This report describes 10 types of ancillary services that distributed generation (DG) can provide to the distribution system. Of these 10 services the feasibility, control strategy, effectiveness, and cost benefits are all analyzed as in the context of a future utility-power market. In this market, services will be provided at a local level that will benefit the customer, the distribution utility, and the transmission company.

  11. Ancillary service provision from distributed generation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This report summarises the findings of a study undertaken to investigate the potential for establishing ancillary service markets at the distribution level in the UK. Existing arrangements for ancillary service markets globally, the design of these markets, regulatory and legislative changes that may be required, different forms of distributed generation (DG), and prospects of increasing the connection to the distributed network are examined along with commercial frameworks and technical procedures, infrastructure requirements, and the effects on different market participants. The scope for new ancillary services at the distribution level, ancillary services from DG, the prospects for DG, commercial and technical aspects, and impact assessments are reviewed.

  12. Ancillary Services from Wind Farms

    DEFF Research Database (Denmark)

    Meeting the EU objectives of sustainable energy supply in the near future involves a dramatic increase of the electricity demand covered by variable renewable sources, among which wind power holds an important role. This important role comes together with ever increasing requirements of wind powe...... plants ability of delivering ancillary services to the power system. The presentation attempts at giving an overview of the present (and future) research on the ability of large (offshore) wind farms to provide power system services.......Meeting the EU objectives of sustainable energy supply in the near future involves a dramatic increase of the electricity demand covered by variable renewable sources, among which wind power holds an important role. This important role comes together with ever increasing requirements of wind power...

  13. Epithelial adhesion mediated by pilin SpaC is required for Lactobacillus rhamnosus GG-induced cellular responses.

    Science.gov (United States)

    Ardita, Courtney S; Mercante, Jeffrey W; Kwon, Young Man; Luo, Liping; Crawford, Madelyn E; Powell, Domonica N; Jones, Rheinallt M; Neish, Andrew S

    2014-08-01

    Lactobacillus rhamnosus GG is a widely used probiotic, and the strain's salutary effects on the intestine have been extensively documented. We previously reported that strain GG can modulate inflammatory signaling, as well as epithelial migration and proliferation, by activating NADPH oxidase 1-catalyzed generation of reactive oxygen species (ROS). However, how strain GG induces these responses is unknown. Here, we report that strain GG's probiotic benefits are dependent on the bacterial-epithelial interaction mediated by the SpaC pilin subunit. By comparing strain GG to an isogenic mutant that lacks SpaC (strain GGΩspaC), we establish that SpaC is necessary for strain GG to adhere to gut mucosa, that SpaC contributes to strain GG-induced epithelial generation of ROS, and that SpaC plays a role in strain GG's capacity to stimulate extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) signaling in enterocytes. In addition, we show that SpaC is required for strain GG-mediated stimulation of cell proliferation and protection against radiologically inflicted intestinal injury. The identification of a critical surface protein required for strain GG to mediate its probiotic influence advances our understanding of the molecular basis for the symbiotic relationship between some commensal bacteria of the gut lumen and enterocytes. Further insights into this relationship are critical for the development of novel approaches to treat intestinal diseases.

  14. Structural basis of typhoid: Salmonella typhi type IVb pilin (PiLS) and cystic fibrosis transmembrane conductance regulator interaction

    Energy Technology Data Exchange (ETDEWEB)

    Balakrishna, A.M.; Saxena, A.; Mok, H. Y.-K.; Swaminathan, K.

    2009-11-01

    The type IVb pilus of the enteropathogenic bacteria Salmonella typhi is a major adhesion factor during the entry of this pathogen into gastrointestinal epithelial cells. Its target of adhesion is a stretch of 10 residues from the first extracellular domain of cystic fibrosis transmembrane conductance regulator (CFTR). The crystal structure of the N-terminal 25 amino acid deleted S. typhi native PilS protein ({Delta}PilS), which makes the pilus, was determined at 1.9 {angstrom} resolution by the multiwavelength anomalous dispersion method. Also, the structure of the complex of {Delta}PilS and a target CFTR peptide, determined at 1.8 {angstrom}, confirms that residues 113-117 (NKEER) of CFTR are involved in binding with the pilin protein and gives us insight on the amino acids that are essential for binding. Furthermore, we have also explored the role of a conserved disulfide bridge in pilus formation. The subunit structure and assembly architecture are crucial for understanding pilus functions and designing suitable therapeutics against typhoid.

  15. Structural Basis of Typhoid: Salmonella typhi Type IVb pilin (PilS) and Cystic Fibrosis Transmembrane Conductance Regulatory Interaction

    Energy Technology Data Exchange (ETDEWEB)

    Balakrishna, A.; Saxena, A; Mok, H; Swaminathan, K

    2009-01-01

    The type IVb pilus of the enteropathogenic bacteria Salmonella typhi is a major adhesion factor during the entry of this pathogen into gastrointestinal epithelial cells. Its target of adhesion is a stretch of 10 residues from the first extracellular domain of cystic fibrosis transmembrane conductance regulator (CFTR). The crystal structure of the N-terminal 25 amino acid deleted S. typhi native PilS protein (PilS), which makes the pilus, was determined at 1.9 A resolution by the multiwavelength anomalous dispersion method. Also, the structure of the complex of PilS and a target CFTR peptide, determined at 1.8 A, confirms that residues 113-117 (NKEER) of CFTR are involved in binding with the pilin protein and gives us insight on the amino acids that are essential for binding. Furthermore, we have also explored the role of a conserved disulfide bridge in pilus formation. The subunit structure and assembly architecture are crucial for understanding pilus functions and designing suitable therapeutics against typhoid.

  16. Structural basis of typhod: Salmonella typhi type IVb pilin (PilS) and cystic fibrosis transmembrane conductance regulator interaction

    Energy Technology Data Exchange (ETDEWEB)

    Balakrishna, A.; Saxena, A; Mok, H; Swaminathan, K

    2009-01-01

    The type IVb pilus of the enteropathogenic bacteria Salmonella typhi is a major adhesion factor during the entry of this pathogen into gastrointestinal epithelial cells. Its target of adhesion is a stretch of 10 residues from the first extracellular domain of cystic fibrosis transmembrane conductance regulator (CFTR). The crystal structure of the N-terminal 25 amino acid deleted S. typhi native PilS protein (PilS), which makes the pilus, was determined at 1.9 A resolution by the multiwavelength anomalous dispersion method. Also, the structure of the complex of PilS and a target CFTR peptide, determined at 1.8 A, confirms that residues 113-117 (NKEER) of CFTR are involved in binding with the pilin protein and gives us insight on the amino acids that are essential for binding. Furthermore, we have also explored the role of a conserved disulfide bridge in pilus formation. The subunit structure and assembly architecture are crucial for understanding pilus functions and designing suitable therapeutics against typhoid.

  17. An overview of ancillary services in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Lobato Miguelez, Enrique; Egido Cortes, Ignacio; Rouco Rodriguez, Luis; Lopez Camino, Gerardo [School of Engineering of Universidad Pontifica Comillas, C/Alberto Aguilera, 23, 28015 Madrid (Spain)

    2008-03-15

    Under a deregulated environment, ancillary services (AS) are defined as the set of products separated from the energy production, which are related to security and reliability of a power system. Ancillary services can be classified in: (a) active power ancillary services (load-frequency control (LFC) - including primary control, automatic generation control (AGC), tertiary control, balancing service and black start provision) and (b) reactive power ancillary services (voltage control). The system operator is the entity responsible for the secure operation of the power system and in this way, the management of all the AS is considered a specific function of the system operator. Under a deregulated framework, ancillary services are separated from the energy production, and can be mandatory or remunerated under market-driven mechanisms. This paper overviews the management of ancillary services in the Spanish power system, including a detailed technical description of the services and the organization of the ancillary services markets. In addition, a comprehensive review of different optimization algorithms and tools used by the agents and system operator within the Spanish electricity business is presented. (author)

  18. Coldwater River NWR Ancillary Bird Observations 2006

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Ancillary bird observations on Coldwater River NWR in 2006 were recorded by local birders. No sampling design was used to generate the observations

  19. Coldwater River NWR Ancillary Bird Observations 2009

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Ancillary bird observations on Coldwater River NWR in 2009 were recorded by local birders. No sampling design was used to generate the observations

  20. Shewanella Oneidensis MR-1 Msh Pilin Proteins are Involved in Extracellular Electron Transfer in Microbial Fuel Cells

    Science.gov (United States)

    2011-01-01

    comparison of the 16 MR-1 Msh pilin complex proteins to Vibrio cholerae O1 biovar El Tor (tax id: 686) using the BLAST-search algorithm [21] for proteins... Vibrio cholerae mannose-sensitive hemagglutinin type 4 pilus gene locus. J Bacteriol 1999;181:1110–7. [23] Ringeisen BR, Henderson E, Wu PK...BLASTp) with default algorithm parameters. Sequence homology of MR-1 Msh proteins to the well-studied Msh pilin complex from V. cholera [22] allowed

  1. Exogam with its ancillary detectors

    Energy Technology Data Exchange (ETDEWEB)

    Theisen, Ch. [CEA Saclay, Dept. d' Astrophysique, de Physique des Particules de Physique Nucleaire et de l' Instrumentation Associee, 91- Gif sur Yvette (France)

    2004-07-01

    The goal of the meeting was to discuss the status of experiments using Exogam and its ancillary detectors. Presentations include details of experiments already run and those in preparation. This document gathers most of the slides presented at the meeting. The results of 7 experiments are described. There are 9 contributions as it follows: 1) presentation of the Vamos spectrometer p.1-15, 2) the Clara (detector) and Prisma (spectrometer) setup: status and perspectives p.16-33, 3) experiment E344aS: shape coexistence near the N=Z line and collective properties of Kr isotopes investigated by low-energy Coulomb excitation p.34-56, 4) experiment E389: study of effective charges at Sm{sup 100} via the nuclear lifetime measurements in Pd{sup 96} and Cd{sup 98} p.57-68, 5) experiment E375: spectroscopy of trans-fermium nuclei p.69-91, 6) experiment E408S: He{sup 8} on Pb{sup 208} and Bi{sup 209} p.92-102, 7) experiment E462: very neutron rich calcium isotopes at N=32, structure of magic Ca{sup 54} studied by gamma-spectroscopy with deep inelastic reactions p.103-115, 8) experiment E451: searching for T=D pairing and a new coupling scheme in Pd{sup 92} and Ru{sup 88} p.116-141, and 9) experiment E404aS: identification of gamma rays in nuclei around the drip-line nucleus Sm{sup 130}, probing the maximally deformed light rare earth region.

  2. Modification of Pseudomonas aeruginosa Pa5196 type IV Pilins at multiple sites with D-Araf by a novel GT-C family Arabinosyltransferase, TfpW.

    Science.gov (United States)

    Kus, Julianne V; Kelly, John; Tessier, Luc; Harvey, Hanjeong; Cvitkovitch, Dennis G; Burrows, Lori L

    2008-11-01

    Pseudomonas aeruginosa Pa5196 produces type IV pilins modified with unusual alpha1,5-linked d-arabinofuranose (alpha1,5-D-Araf) glycans, identical to those in the lipoarabinomannan and arabinogalactan cell wall polymers from Mycobacterium spp. In this work, we identify a second strain of P. aeruginosa, PA7, capable of expressing arabinosylated pilins and use a combination of site-directed mutagenesis, electrospray ionization mass spectrometry (MS), and electron transfer dissociation MS to identify the exact sites and extent of pilin modification in strain Pa5196. Unlike previously characterized type IV pilins that are glycosylated at a single position, those from strain Pa5196 were modified at multiple sites, with modifications of alphabeta-loop residues Thr64 and Thr66 being important for normal pilus assembly. Trisaccharides of alpha1,5-D-Araf were the principal modifications at Thr64 and Thr66, with additional mono- and disaccharides identified on Ser residues within the antiparallel beta sheet region of the pilin. TfpW was hypothesized to encode the pilin glycosyltransferase based on its genetic linkage to the pilin, weak similarity to membrane-bound GT-C family glycosyltransferases (which include the Mycobacterium arabinosyltransferases EmbA/B/C), and the presence of characteristic motifs. Loss of TfpW or mutation of key residues within the signature GT-C glycosyltransferase motif completely abrogated pilin glycosylation, confirming its involvement in this process. A Pa5196 pilA mutant complemented with other Pseudomonas pilins containing potential sites of modification expressed nonglycosylated pilins, showing that TfpW's pilin substrate specificity is restricted. TfpW is the prototype of a new type IV pilin posttranslational modification system and the first reported gram-negative member of the GT-C glycosyltransferase family.

  3. Interesting sequence differences between the pilin gene inversion regions of Moraxella lacunata ATCC 17956 and Moraxella bovis Epp63.

    Science.gov (United States)

    Rozsa, F W; Marrs, C F

    1991-07-01

    The bacterium Moraxella lacunata is a causative agent of human conjunctivitis and keratitis. We have previously reported construction of plasmid pMxL1, which includes a 5.9-kb fragment on which the pilin gene inversion region of M. lacunata resides. The inversion region of pMxL1 was shown to invert when pMxL1 was in an Escherichia coli host cell. In this report, we present Western immunoblot analysis using Moraxella bovis Epp63 anti-I and anti-Q pilin sera which demonstrate that pMxL1 makes pilin only when in orientation 1. The sequence of the pMxL1 plasmid containing the invertible region contains a perfect tandem repeat of 19 bp in the orientation 1 nonexpressed pilin gene at the middle of the recombination junction site. This 19-bp insert causes a frameshift and disrupts the pilin gene. The predicted amino acid sequence of this nonfunctional pilin gene (with the 19-bp repeat subtracted) bears closest resemblance to M. bovis Epp63 Q pilin sequence, although the other (functional) M. lacunata pilin encoded by pMxL1 shows slightly higher homology to Q pilin. Comparison of the pMxL1 sequence with that of the M. bovis Epp63 sequence shows two other particularly interesting differences. One is a 15-bp sequence addition found in pMxL1 at the 60-bp region previously reported as a possible M. bovis recombinational enhancer. The second is an AT deletion in pMxL1 compared with Epp63 within an open reading frame (tfpB) which results in the pMxL1 tfpB open reading frame being one-third shorter than in Epp63. The DNA sequences in these three altered regions from the M. lacunata strain from which pMxL1 was derived were amplified by polymerase chain reaction and sequenced. The parent strain was found to contain the differences seen in pMxL1. Comparison of the M.bovis and M. lacunata pilin gene amino acid sequences is also presented.

  4. Characterization of pilin genes from seven serologically defined prototype strains of Moraxella bovis.

    OpenAIRE

    1994-01-01

    Numerous field isolates of Moraxella bovis have previously been classified by serological techniques into seven serogroups, each defined by homologous cross-reaction with antisera prepared against purified pili of a single prototype strain. The gene encoding pilin from each of the prototype strains has been characterized by nucleotide sequence determination. The coding sequences show extensive homology (70 to 80%) while the proximal downstream sequences show a dichotomy into nonhomologous set...

  5. Ancillary Testing in Lung Cancer Diagnosis

    Directory of Open Access Journals (Sweden)

    William Dubinski

    2012-01-01

    Full Text Available The pathologic diagnosis of lung cancer historically has relied primarily on morphologic features of tumors in histologic sections. With the emergence of new targeted therapies, the pathologist is called upon increasingly to provide not only accurate typing of lung cancers, but also to provide prognostic and predictive information, based on a growing number of ancillary tests, that may have significant impact on patient management. This review provides an overview of ancillary tests currently used in the pathologic diagnosis of lung cancer, with a focus on immunohistochemistry and molecular diagnostics.

  6. Cell surface display of minor pilin adhesins in the form of a simple heterodimeric assembly in Corynebacterium diphtheriae.

    Science.gov (United States)

    Chang, Chungyu; Mandlik, Anjali; Das, Asis; Ton-That, Hung

    2011-03-01

    Pilus assembly in Gram-positive bacteria occurs by a two-step mechanism, whereby pilins are polymerized and then covalently anchored to the cell wall. In Corynebacterium diphtheriae, the pilin-specific sortase SrtA catalyses polymerization of the SpaA-type pilus, consisting of the shaft pilin SpaA, tip pilin SpaC and minor pilin SpaB. Cell wall anchoring of the SpaA polymers is triggered when SrtA incorporates SpaB into the pilus base via lysine-mediated transpeptidation; anchoring to the cell wall peptidoglycan is subsequently catalysed by the housekeeping sortase SrtF. Here we show that SpaB and SpaC formed a heterodimer independent of SpaA polymerization. SrtA was absolutely required for the formation of the SpaBC heterodimer, while SrtF facilitated the optimal cell wall anchoring of this heterodimer. Alanine substitution of the SpaB lysine residue K139 or truncation of the SpaB cell wall-sorting signal (CWSS) abolished assembly of the SpaBC heterodimer, hence underscoring SpaB function in transpeptidation and cell wall linkage. Importantly, sortase specificity for the cell wall-anchoring step was found to be dependent on the LAFTG motif within the SpaB CWSS. Thus, C. diphtheriae employs a common sortase-catalysed mechanism involving lysine-mediated transpeptidation to generate both adhesive pilus and simple heterodimeric structures on the bacterial the cell wall.

  7. Power system studies of new ancillary services

    DEFF Research Database (Denmark)

    Hansen, Anca Daniela; Altin, Müfit

    The objective of this report is to illustrate and analyse, by means of simulation test cases, the impact of wind power advanced ancillary services, like inertial response (IR), power oscillation damping (POD) and synchronising power (SP) on the power system. Generic models for wind turbine, wind...... power plant and power system are used in the investigation....

  8. Interesting sequence differences between the pilin gene inversion regions of Moraxella lacunata ATCC 17956 and Moraxella bovis Epp63.

    OpenAIRE

    1991-01-01

    The bacterium Moraxella lacunata is a causative agent of human conjunctivitis and keratitis. We have previously reported construction of plasmid pMxL1, which includes a 5.9-kb fragment on which the pilin gene inversion region of M. lacunata resides. The inversion region of pMxL1 was shown to invert when pMxL1 was in an Escherichia coli host cell. In this report, we present Western immunoblot analysis using Moraxella bovis Epp63 anti-I and anti-Q pilin sera which demonstrate that pMxL1 makes p...

  9. A conserved type IV pilin signal peptide H-domain is critical for the post-translational regulation of flagella-dependent motility.

    Science.gov (United States)

    Esquivel, Rianne N; Pohlschroder, Mechthild

    2014-08-01

    In many bacteria and archaea, type IV pili facilitate surface adhesion, the initial step in biofilm formation. Haloferax volcanii has a specific set of adhesion pilins (PilA1-A6) that, although diverse, contain an absolutely conserved signal peptide hydrophobic (H) domain. Data presented here demonstrate that these pilins (PilA1-A6) also play an important role in regulating flagella-dependent motility, which allows cells to rapidly transition between planktonic and sessile states. Cells lacking adhesion pilins exhibit a severe motility defect, however, expression of any one of the adhesion pilins in trans can rescue the motility and adhesion. Conversely, while deleting pilB3-C3, genes required for PilA pilus biosynthesis, results in cells lacking pili and having an adhesion defect, it does not affect motility, indicating that motility regulation requires the presence of pilins, but not assembled pili. Mutagenesis studies revealed that the pilin-dependent motility regulatory mechanism does not require the diverse C-terminal region of the PilA pilins but specifically involves the conserved H-domain. This novel post-translational regulatory mechanism, which employs components that promote biofilm formation to inhibit motility, can provide a rapid response to changing environmental conditions. A model for this regulatory mechanism, which may also be present in other prokaryotes, is discussed.

  10. Sequence analysis of the inversion region containing the pilin genes of Moraxella bovis.

    Science.gov (United States)

    Fulks, K A; Marrs, C F; Stevens, S P; Green, M R

    1990-01-01

    Moraxella bovis EPP63 is able to produce two antigenically distinct pili called Q and I pili (previously called beta and alpha pili). Hybridization studies have shown that the transition between the types is due to inversion of a 2.1-kilobase segment of chromosomal DNA. We present the sequence of a 4.1-kilobase region of cloned DNA spanning the entire inversion region in orientation 1 (Q pilin expressed). Comparison of this sequence with the sequence of the polymerase chain reaction-amplified genomic DNA from orientation 2 (I pilin expressed) allows the site-specific region of recombination to be localized to a 26-base-pair region in which sequence similarity to the left inverted repeat of the Salmonella typhimurium hin system was previously noted. In addition, 50% sequence similarity was seen in a 60-base-pair segment of our sequence to the recombinational enhancer of bacteriophage P1, an inversion system related to the hin system of S. typhimurium. Finally, two open reading frames representing potential genes were identified.

  11. Mucosal adhesion properties of the probiotic Lactobacillus rhamnosus GG SpaCBA and SpaFED pilin subunits

    NARCIS (Netherlands)

    Ossowski, von I.; Reunanen, J.; Satokari, R.M.; Vesterlund, S.; Kankainen, M.; Huhtinen, H.; Tynkkynen, S.; Salminen, S.; Vos, de W.M.; Palva, A.

    2010-01-01

    Lactobacillus rhamnosus GG is a well-established Gram-positive probiotic strain, whose health-benefiting properties are in part dependent upon a prolonged residency in the gastrointestinal tract and likely dictated by an adherence to the intestinal mucosa. Previously, we identified two pilus gene cl

  12. Isolation, expression, and nucleotide sequencing of the pilin structural gene of the Brazilian purpuric fever clone of Haemophilus influenzae biogroup aegyptius.

    Science.gov (United States)

    St Geme, J W; Falkow, S

    1993-05-01

    In this study we isolated the pilin gene from the Brazilian purpuric fever (BPF) clone of Haemophilus influenzae biogroup aegyptius, expressed the gene in Escherichia coli, and determined its nucleotide sequence. Comparison of the nucleotide sequence of the BPF pilin gene with the sequences of pilin genes from strains of H. influenzae sensu stricto demonstrated a high degree of identity. Consistent with this observation, hemagglutination inhibition studies performed with a series of glycoconjugates indicated that BPF pili and H. influenzae type b pili possess the same erythrocyte receptor specificity.

  13. Illustration of Modern Wind Turbine Ancillary Services

    DEFF Research Database (Denmark)

    Margaris, Ioannis D.; Hansen, Anca Daniela; Sørensen, Poul Ejnar

    2010-01-01

    Increasing levels of wind power penetration in modern power systems has set intensively high standards with respect to wind turbine technology during the last years. Security issues have become rather critical and operation of wind farms as conventional power plants is becoming a necessity as wind...... turbines replace conventional units on the production side. This article includes a review of the basic control issues regarding the capability of the Doubly Fed Induction Generator (DFIG) wind turbine configuration to fulfill the basic technical requirements set by the system operators and contribute...... to power system security. An overview of ancillary services provided by wind turbine technology nowadays is provided, i.e., fault ride-through capability, reactive power supply and frequency-active power control....

  14. Illustration of Modern Wind Turbine Ancillary Services

    Directory of Open Access Journals (Sweden)

    Ioannis D. Margaris

    2010-06-01

    Full Text Available Increasing levels of wind power penetration in modern power systems has set intensively high standards with respect to wind turbine technology during the last years. Security issues have become rather critical and operation of wind farms as conventional power plants is becoming a necessity as wind turbines replace conventional units on the production side. This article includes a review of the basic control issues regarding the capability of the Doubly Fed Induction Generator (DFIG wind turbine configuration to fulfill the basic technical requirements set by the system operators and contribute to power system security. An overview of ancillary services provided by wind turbine technology nowadays is provided, i.e., fault ride-through capability, reactive power supply and frequency-active power control.

  15. Integration of Flexible Consumers in the Ancillary Service Markets

    DEFF Research Database (Denmark)

    Biegel, Benjamin; Westenholz, Mikkel; Hansen, Lars Henrik

    2014-01-01

    services. In this work we present a simple method based on the existing ancillary service markets that resolves these issues via increased information and communication technology. The method allows an aggregator to continuously utilize the markets for slower ancillary service to ensure that its portfolio......Flexible consumption devices are often able to quickly adjust the power consumption making these devices very well suited as providers of fast ancillary services such as primary and secondary reserves. As these reserves are among the most well-paid ancillary services, it is an interesting idea...... to let an aggregator control a portfolio of flexible consumption devices and sell the accumulated flexibility in the primary and secondary reserve markets. However, two issues make it difficult for a portfolio of consumption devices to provide ancillary services: First, flexible consumption devices only...

  16. Purification and characterization of a pilin specific for Brazilian purpuric fever-associated Haemophilus influenzae biogroup aegyptius (H. aegyptius) strains.

    Science.gov (United States)

    Weyant, R S; Bibb, W F; Stephens, D S; Holloway, B P; Moo-Penn, W F; Birkness, K A; Helsel, L O; Mayer, L W

    1990-04-01

    Brazilian purpuric fever (BPF) is a recently described fatal pediatric disease caused by systemic infection with Haemophilus influenzae biogroup aegyptius. Previous studies have shown that all H. influenzae biogroup aegyptius strains isolated from BPF cases and case contacts share several unique phenotypic and genotypic characteristics that differentiate them from other H. influenzae biogroup aegyptius strains isolated from conjunctivitis cases in Brazil. One key characteristic of this BPF clone is reactivity in a BPF-specific monoclonal antibody enzyme-linked immunosorbent assay. We have purified and partially characterized a pilin, referred to as the 25-kilodalton (kDa) protein. Aggregates of this protein contain a heat-labile epitope which is recognized by a monoclonal antibody used in the BPF-specific enzyme-linked immunosorbent assay. The protein has a molecular weight of approximately 25,000, is insoluble in most detergents, and fractionates with outer membrane vesicles after LiCl extraction. Biochemical analysis of the 25-kDa protein shows it to have an amino acid composition similar but not identical to that of the H. influenzae type b pilin. The sequence of 20 N-terminal amino acids of the 25-kDa protein shows almost complete homology with the N terminus of the H. influenzae type b pilin and the types 1 and P pilins of Escherichia coli. Transmission electron microscopic analysis of the purified protein shows the presence of filamentous structures similar in morphology to those of H. influenzae pili. Reactivity between the 25-kDa protein and the BPF-specific monoclonal antibody is demonstrated by Western blotting (immunoblotting) and colloidal gold-enhanced immunoelectron microscopy. Hemadsorption analysis shows that expression of this protein is associated with increases in piliated cells and enhanced binding of these cells to human erythrocytes. These studies indicate that expression of the 25-kDa protein is a characteristic unique to the BPF clone and

  17. Minimum detection windows, PI-line existence and uniqueness for helical cone-beam scanning of variable pitch.

    Science.gov (United States)

    Ye, Yangbo; Zhu, Jiehua; Wang, Ge

    2004-03-01

    The goal of this paper is to study Cone-beam CT scanning along a helix of variable pitch. First the rationale and applications in medical imaging of variable pitch CT reconstruction are explained. Then formulas for the minimum detection window are derived. The main part of the paper proves a necessary and sufficient condition for the existence and uniqueness of PI-lines inside this variable pitch helix. These results are necessary steps toward an exact reconstruction algorithm for helix scanning of variable pitch, generalizing Katsevich's formula on constant pitch exact reconstruction. It is shown through an example that, when the derivative of the pitch function is not convex, or when the pitch function passes a inflection point and begins to slow down, PI-lines may be not unique near the rim of the helix cylinder. The conclusion is that the restriction on the pitch function is weaker, if the object is placed well within the helix cylinder and far from its rim, in order to preserve the uniqueness of PI-lines. If the object is near the rim, the restriction condition on the allowable pitch functions becomes stronger.

  18. Transcutaneous immunization with toxin-coregulated pilin A induces protective immunity against Vibrio cholerae O1 El Tor challenge in mice.

    Science.gov (United States)

    Rollenhagen, Julianne E; Kalsy, Anuj; Cerda, Francisca; John, Manohar; Harris, Jason B; Larocque, Regina C; Qadri, Firdausi; Calderwood, Stephen B; Taylor, Ronald K; Ryan, Edward T

    2006-10-01

    Toxin-coregulated pilin A (TcpA) is the main structural subunit of a type IV bundle-forming pilus of Vibrio cholerae, the cause of cholera. Toxin-coregulated pilus is involved in formation of microcolonies of V. cholerae at the intestinal surface, and strains of V. cholerae deficient in TcpA are attenuated and unable to colonize intestinal surfaces. Anti-TcpA immunity is common in humans recovering from cholera in Bangladesh, and immunization against TcpA is protective in murine V. cholerae models. To evaluate whether transcutaneously applied TcpA is immunogenic, we transcutaneously immunized mice with 100 mug of TcpA or TcpA with an immunoadjuvant (cholera toxin [CT], 50 mug) on days 0, 19, and 40. Mice immunized with TcpA alone did not develop anti-TcpA responses. Mice that received transcutaneously applied TcpA and CT developed prominent anti-TcpA immunoglobulin G (IgG) serum responses but minimal anti-TcpA IgA. Transcutaneous immunization with CT induced prominent IgG and IgA anti-CT serum responses. In an infant mouse model, offspring born to dams transcutaneously immunized either with TcpA and CT or with CT alone were challenged with 10(6) CFU (one 50% lethal dose) wild-type V. cholerae O1 El Tor strain N16961. At 48 h, mice born to females transcutaneously immunized with CT alone had 36% +/- 10% (mean +/- standard error of the mean) survival, while mice born to females transcutaneously immunized with TcpA and CT had 69% +/- 6% survival (P < 0.001). Our results suggest that transcutaneous immunization with TcpA and an immunoadjuvant induces protective anti-TcpA immune responses. Anti-TcpA responses may contribute to an optimal cholera vaccine.

  19. A combined mass spectrometry strategy for complete posttranslational modification mapping of Neisseria meningitidis major pilin.

    Science.gov (United States)

    Gault, Joseph; Malosse, Christian; Duménil, Guillaume; Chamot-Rooke, Julia

    2013-11-01

    Herein, we report a new approach, based on the combination of mass profiling and tandem mass spectrometry, to address the issue of localising all post-translational modifications (PTMs) on the major pilin protein PiIE expressed by the pathogenic Neisseria species. PilE is the main component of type IV pili; filamentous organelles expressed at the surface of many bacterial pathogens and important virulence factors. Previous reports have shown that PilE can harbour various combinations of PTMs and have established strong links between PTM and pathogenesis. Complete PTM mapping of proteins involved in bacterial infection is therefore highly desirable. The methodology we propose here allowed us to fully characterise the PilE proteoforms of Neisseria meningitidis strain 8013, definitively identifying all PTMs present on all proteoforms and localising their position on the protein backbone. These modifications include a processed and methylated N-terminus, disulfide bridge, glycosylation and glycerophosphorylation at two different sites. A key element of our approach is high resolution, intact mass measurement of the proteoforms, a piece of information completely lacking in all classical bottom-up proteomics strategies used for PTM analysis and without which it is difficult to ensure complete PTM mapping.

  20. Promoting crystallisation of the Salmonella enteritidis fimbriae 14 pilin SefD using deuterium oxide

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Bing; Garnett, James A.; Lee, Wei-chao; Lin, Jing; Salgado, Paula; Taylor, Jonathan; Xu, Yingqi; Lambert, Sebastian; Cota, Ernesto [Centre for Structural Biology and Division of Molecular Biosciences, Imperial College London, South Kensington, London SW7 2AZ (United Kingdom); Matthews, Steve, E-mail: s.j.matthews@imperial.ac.uk [Centre for Structural Biology and Division of Molecular Biosciences, Imperial College London, South Kensington, London SW7 2AZ (United Kingdom)

    2012-05-04

    Highlights: Black-Right-Pointing-Pointer The benefits of D{sub 2}O in screening for crystallisation was explored. Black-Right-Pointing-Pointer The crystal structures of the SefD pilin in both H{sub 2}O and D{sub 2}O reveal differences. Black-Right-Pointing-Pointer Crystallisation improvements are explained by altered interactions in D{sub 2}O crystals. Black-Right-Pointing-Pointer D{sub 2}O is useful additive in sparse-matrix screening for crystallisation. -- Abstract: The use of heavy water (D{sub 2}O) as a solvent is commonplace in many spectroscopic techniques for the study of biological macromolecules. A significant deuterium isotope effect exists where hydrogen-bonding is important, such as in protein stability, dynamics and assembly. Here we illustrate the use of D{sub 2}O in additive screening for the production of reproducible diffraction-quality crystals for the Salmonella enteritidis fimbriae 14 (SEF14) putative tip adhesin, SefD.

  1. Load Participation in Ancillary Services System from An Operator Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Kujawski, Don [PJM, Audubon, PA (United States); Petri, Mark C. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2011-10-25

    Ancillary services as defined by FERC (Order 888) distinguished by response time, duration, frequency. Met when DR has capability to balance supply and demand; and LMP payment to DR is cost effective.

  2. Survey of U.S. Ancillary Services Markets

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Zhi [Argonne National Lab. (ANL), Argonne, IL (United States); Levin, Todd [Argonne National Lab. (ANL), Argonne, IL (United States); Conzelmann, Guenter [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-01-01

    In addition to providing energy to end-consumers, power system operators are also responsible for ensuring system reliability. To this end, power markets maintain an array of ancillary services to ensure it is always possible to balance the supply and demand for energy in real-time. A subset of these ancillary services are commonly procured through market-based mechanisms: namely, Regulation, Spinning, and Non-spinning Reserves.

  3. Identification of Haloferax volcanii Pilin N-Glycans with Diverse Roles in Pilus Biosynthesis, Adhesion, and Microcolony Formation.

    Science.gov (United States)

    Esquivel, Rianne N; Schulze, Stefan; Xu, Rachel; Hippler, Michael; Pohlschroder, Mechthild

    2016-05-13

    N-Glycosylation is a post-translational modification common to all three domains of life. In many archaea, the oligosacharyltransferase (AglB)-dependent N-glycosylation of flagellins is required for flagella assembly. However, whether N-glycosylation is required for the assembly and/or function of the structurally related archaeal type IV pili is unknown. Here, we show that of six Haloferax volcanii adhesion pilins, PilA1 and PilA2, the most abundant pilins in pili of wild-type and ΔaglB strains, are modified under planktonic conditions in an AglB-dependent manner by the same pentasaccharide detected on H. volcanii flagellins. However, unlike wild-type cells, which have surfaces decorated with discrete pili and form a dispersed layer of cells on a plastic surface, ΔaglB cells have thick pili bundles and form microcolonies. Moreover, expressing PilA1, PilA2, or PilA6 in ΔpilA[1-6]ΔaglB stimulates microcolony formation compared with their expression in ΔpilA[1-6]. Conversely, expressing PilA3 or PilA4 in ΔpilA[1-6] cells results in strong surface adhesion, but not microcolony formation, and neither pilin stimulates surface adhesion in ΔpilA[1-6]ΔaglB cells. Although PilA4 assembles into pili in the ΔpilA[1-6]ΔaglB cells, these pili are, unlike wild-type pili, curled, perhaps rendering them non-functional. To our knowledge, this is the first demonstration of a differential effect of glycosylation on pilus assembly and function of paralogous pilins. The growth of wild-type cells in low salt media, a condition that decreases AglB glycosylation, also stimulates microcolony formation and inhibits motility, supporting our hypothesis that N-glycosylation plays an important role in regulating the transition between planktonic to sessile cell states as a response to stress.

  4. Medical Researchers' Ancillary Care Obligations: The Relationship-Based Approach.

    Science.gov (United States)

    Olson, Nate W

    2016-06-01

    In this article, I provide a new account of the basis of medical researchers' ancillary care obligations. Ancillary care in medical research, or medical care that research participants need but that is not required for the validity or safety of a study or to redress research injuries, is a topic that has drawn increasing attention in research ethics over the last ten years. My view, the relationship-based approach, improves on the main existing theory, Richardson and Belsky's 'partial-entrustment model', by avoiding its problematic restriction on the scope of health needs for which researchers could be obligated to provide ancillary care. Instead, it grounds ancillary care obligations in a wide range of morally relevant features of the researcher-participant relationship, including the level of engagement between researchers and participants, and weighs these factors against each other. I argue that the level of engagement, that is, the duration and intensity of interactions, between researchers and participants matters for ancillary care because of its connection to the meaningfulness of a relationship, and I suggest that other morally relevant features can be grounded in researchers' role obligations.

  5. Ancillary effects of selected acid deposition control policies

    Energy Technology Data Exchange (ETDEWEB)

    Moe, R.J.; Lyke, A.J.; Nesse, R.J.

    1986-08-01

    NAPAP is examining a number of potential ways to reduce the precursors (sulfur dioxide and nitrogen oxides) to acid deposition. However, the policies to reduce acid deposition will have other physical, biological and economic effects unrelated to acid deposition. For example, control policies that reduce sulfur dioxide emissions may also increase visibility. The effects of an acid deposition policy that are unrelated to acid deposition are referred to as ''ancillary'' effects. This reserch identifies and characterizes the principle physical and economic ancillary effects associated with acid deposition control and mitigation policies. In this study the ancillary benefits associated with four specific acid deposition policy options were investigated. The four policy options investigated are: (1) flue gas desulfurization, (2) coal blending or switching, (3) reductions in automobile emissions of NO/sub x/, and (4) lake liming. Potential ancillary benefits of each option were identified and characterized. Particular attention was paid to the literature on economic valuation of potential ancillary effects.

  6. The type IV pilin, PilA, is required for full virulence of Francisella tularensis subspecies tularensis

    Directory of Open Access Journals (Sweden)

    Forslund Anna-Lena

    2010-08-01

    Full Text Available Abstract Background All four Francisella tularensis subspecies possess gene clusters with potential to express type IV pili (Tfp. These clusters include putative pilin genes, as well as pilB, pilC and pilQ, required for secretion and assembly of Tfp. A hallmark of Tfp is the ability to retract the pilus upon surface contact, a property mediated by the ATPase PilT. Interestingly, out of the two major human pathogenic subspecies only the highly virulent type A strains have a functional pilT gene. Results In a previous study, we were able to show that one pilin gene, pilA, was essential for virulence of a type B strain in a mouse infection model. In this work we have examined the role of several Tfp genes in the virulence of the pathogenic type A strain SCHU S4. pilA, pilC, pilQ, and pilT were mutated by in-frame deletion mutagenesis. Interestingly, when mice were infected with a mixture of each mutant strain and the wild-type strain, the pilA, pilC and pilQ mutants were out-competed, while the pilT mutant was equally competitive as the wild-type. Conclusions This suggests that expression and surface localisation of PilA contribute to virulence in the highly virulent type A strain, while PilT was dispensable for virulence in the mouse infection model.

  7. Loads Providing Ancillary Services: Review of International Experience

    Energy Technology Data Exchange (ETDEWEB)

    Heffner, Grayson; Goldman, Charles; Kintner-Meyer, Michael

    2007-05-01

    In this study, we examine the arrangements for and experiences of end-use loads providing ancillary services (AS) in five electricity markets: Australia, the United Kingdom (UK), the Nordic market, and the ERCOT and PJM markets in the United States. Our objective in undertaking this review of international experience was to identify specific approaches or market designs that have enabled customer loads to effectively deliver various ancillary services (AS) products. We hope that this report will contribute to the ongoing discussion in the U.S. and elsewhere regarding what institutional and technical developments are needed to ensure that customer loads can meaningfully participate in all wholesale electricity markets.

  8. A real-time semi-quantitative RT–PCR assay demonstrates that the pilE sequence dictates the frequency and characteristics of pilin antigenic variation in Neisseria gonorrhoeae

    OpenAIRE

    Rohrer, Melissa S.; Lazio, Matthew P.; Seifert, H. Steven

    2005-01-01

    A semi-quantitative real-time RT–PCR assay was designed to measure gonococcal pilin antigenicvariation (SQ-PCR Av assay). This assay employs 17 hybridization probe sets that quantitate subpopulations of pilin transcripts carrying different silent pilin copy sequences and one set that detects total pilE transcript levels. Mixtures of a DNA standard carrying the silent copy being detected and a clone encoding the starting pilE sequence, which is the majority pilE template, provided amplificatio...

  9. Impact of advanced wind power ancillary services on power system

    DEFF Research Database (Denmark)

    Hansen, Anca Daniela; Altin, Müfit

    The objective of this report is to illustrate and analyse, by means of simulation test cases, the impact of wind power advanced ancillary services, like inertial response (IR), power oscillation damping (POD) and synchronising power (SP) on the power system. Generic models for wind turbine, wind...... power plant and power system are used in the investigation....

  10. EV and HP Providing Ancillary Services in the Nordic Region

    DEFF Research Database (Denmark)

    Liu, Zhaoxi; Wu, Qiuwei

    This report covers the analysis of the electric vehicle (EV) and heat pump (HP) providing ancillary services to the power system of the Nordic region including Denmark, Finland, Norway and Sweden. The analysis is to investigate the feasibility of EVs and HPs to serve as demand as frequency reserve...... (DFR) providers in the distribution power system in the four mentioned Nordic countries....

  11. Structure of Streptococcus agalactiae tip pilin GBS104: a model for GBS pili assembly and host interactions

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, Vengadesan [UNESCO Regional Centre for Biotechnology (RCB), Gurgaon 122 016, Haryana (India); Dwivedi, Prabhat [University of Texas Health Science Center, Houston, TX 77030 (United States); Kim, Brandon J. [San Diego State University, 5500 Campanile Drive, San Diego, CA 92182 (United States); Samal, Alexandra; Macon, Kevin [University of Alabama at Birmingham, Birmingham, AL 35294 (United States); Ma, Xin; Mishra, Arunima [University of Texas Health Science Center, Houston, TX 77030 (United States); Doran, Kelly S. [San Diego State University, 5500 Campanile Drive, San Diego, CA 92182 (United States); Ton-That, Hung [University of Texas Health Science Center, Houston, TX 77030 (United States); Narayana, Sthanam V. L., E-mail: narayana@uab.edu [University of Alabama at Birmingham, Birmingham, AL 35294 (United States); UNESCO Regional Centre for Biotechnology (RCB), Gurgaon 122 016, Haryana (India)

    2013-06-01

    The crystal structure of a 75 kDa central fragment of GBS104, a tip pilin from the 2063V/R strain of Streptococcus agalactiae (group B streptococcus; GBS), is reported. The crystal structure of a 75 kDa central fragment of GBS104, a tip pilin from the 2063V/R strain of Streptococcus agalactiae (group B streptococcus; GBS), is reported. In addition, a homology model of the remaining two domains of GBS104 was built and a model of full-length GBS104 was generated by combining the homology model (the N1 and N4 domains) and the crystal structure of the 75 kDa fragment (the N2 and N3 domains). This rod-shaped GBS104 model is constructed of three IgG-like domains (the N1, N2 and N4 domains) and one vWFA-like domain (the N3 domain). The N1 and N2 domains of GBS104 are assembled with distinct and remote segments contributed by the N- and C-termini. The metal-binding site in the N3 domain of GBS104 is in the closed/low-affinity conformation. Interestingly, this domain hosts two long arms that project away from the metal-binding site. Using site-directed mutagenesis, two cysteine residues that lock the N3 domain of GBS104 into the open/high-affinity conformation were introduced. Both wild-type and disulfide-locked recombinant proteins were tested for binding to extracellular matrix proteins such as collagen, fibronectin, fibrinogen and laminin, and an increase in fibronectin binding affinity was identified for the disulfide-locked N3 domain, suggesting that induced conformational changes may play a possible role in receptor binding.

  12. The N-Terminal GYPSY Motif Is Required for Pilin-Specific Sortase SrtC1 Functionality in Lactobacillus rhamnosus Strain GG.

    Science.gov (United States)

    Douillard, François P; Rasinkangas, Pia; Bhattacharjee, Arnab; Palva, Airi; de Vos, Willem M

    2016-01-01

    Predominantly identified in pathogenic Gram-positive bacteria, sortase-dependent pili are also found in commensal species, such as the probiotic-marketed strain Lactobacillus rhamnosus strain GG. Pili are typically associated with host colonization, immune signalling and biofilm formation. Comparative analysis of the N-terminal domains of pilin-specific sortases from various piliated Gram-positive bacteria identified a conserved motif, called GYPSY, within the signal sequence. We investigated the function and role of the GYPSY residues by directed mutagenesis in homologous (rod-shaped) and heterologous (coccoid-shaped) expression systems for pilus formation. Substitutions of some of the GYPSY residues, and more specifically the proline residue, were found to have a direct impact on the degree of piliation of Lb. rhamnosus GG. The present findings uncover a new signalling element involved in the functionality of pilin-specific sortases controlling the pilus biogenesis of Lb. rhamnosus GG and related piliated Gram-positive species.

  13. Ancillary-service costs for 12 US electric utilities

    Energy Technology Data Exchange (ETDEWEB)

    Kirby, B.; Hirst, E.

    1996-03-01

    Ancillary services are those functions performed by electrical generating, transmission, system-control, and distribution-system equipment and people to support the basic services of generating capacity, energy supply, and power delivery. The Federal Energy Regulatory Commission defined ancillary services as ``those services necessary to support the transmission of electric power from seller to purchaser given the obligations of control areas and transmitting utilities within those control areas to maintain reliable operations of the interconnected transmission system.`` FERC divided these services into three categories: ``actions taken to effect the transaction (such as scheduling and dispatching services) , services that are necessary to maintain the integrity of the transmission system [and] services needed to correct for the effects associated with undertaking a transaction.`` In March 1995, FERC published a proposed rule to ensure open and comparable access to transmission networks throughout the country. The rule defined six ancillary services and developed pro forma tariffs for these services: scheduling and dispatch, load following, system protection, energy imbalance, loss compensation, and reactive power/voltage control.

  14. Backbone dynamics of a bacterially expressed peptide from the receptor binding domain of Pseudomonas aeruginosa pilin strain PAK from heteronuclear 1H-15N NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, A. Patricia [University of Washington, Department of Medicinal Chemistry, School of Pharmacy (United States); Spyracopoulos, Leo [Department of Biochemistry (Canada); Irvin, Randall T. [University of Alberta, Department of Medical Microbiology and Immunology (Canada); Sykes, Brian D. [Department of Biochemistry (Canada)

    2000-07-15

    The backbone dynamics of a {sup 15}N-labeled recombinant PAK pilin peptide spanning residues 128-144 in the C-terminal receptor binding domain of Pseudomonas aeruginosa pilin protein strain PAK (Lys{sup 128}-Cys-Thr-Ser-Asp-Gln-Asp-Glu-Gln-Phe-Ile-Pro-Lys-Gly-Cys-Ser-Lys{sup 144}) were probed by measurements of {sup 15}N NMR relaxation. This PAK(128-144) sequence is a target for the design of a synthetic peptide vaccine effective against multiple strains of P. aeruginosa infection. The {sup 15}N longitudinal (T{sub 1}) and transverse (T{sub 2}) relaxation rates and the steady-state heteronuclear {l_brace}{sup 1}H{r_brace}-{sup 15}N NOE were measured at three fields (7.04, 11.74 and 14.1 Tesla), five temperatures (5, 10, 15, 20, and 25 deg. C ) and at pH 4.5 and 7.2. Relaxation data was analyzed using both the 'model-free' formalism [Lipari, G. and Szabo, A. (1982) J. Am. Chem. Soc., 104, 4546-4559 and 4559-4570] and the reduced spectral density mapping approach [Farrow, N.A., Szabo, A., Torchia, D.A. and Kay, L.E. (1995) J. Biomol. NMR, 6, 153-162]. The relaxation data, spectral densities and order parameters suggest that the type I and type II {beta}-turns spanning residues Asp{sup 134}-Glu-Gln-Phe{sup 137} and Pro{sup 139}-Lys-Gly-Cys{sup 142}, respectively, are the most ordered and structured regions of the peptide. The biological implications of these results will be discussed in relation to the role that backbone motions play in PAK pilin peptide immunogenicity, and within the framework of developing a pilin peptide vaccine capable of conferring broad immunity across P. aeruginosa strains.

  15. Optimal generator bidding strategies for power and ancillary services

    Science.gov (United States)

    Morinec, Allen G.

    As the electric power industry transitions to a deregulated market, power transactions are made upon price rather than cost. Generator companies are interested in maximizing their profits rather than overall system efficiency. A method to equitably compensate generation providers for real power, and ancillary services such as reactive power and spinning reserve, will ensure a competitive market with an adequate number of suppliers. Optimizing the generation product mix during bidding is necessary to maximize a generator company's profits. The objective of this research work is to determine and formulate appropriate optimal bidding strategies for a generation company in both the energy and ancillary services markets. These strategies should incorporate the capability curves of their generators as constraints to define the optimal product mix and price offered in the day-ahead and real time spot markets. In order to achieve such a goal, a two-player model was composed to simulate market auctions for power generation. A dynamic game methodology was developed to identify Nash Equilibria and Mixed-Strategy Nash Equilibria solutions as optimal generation bidding strategies for two-player non-cooperative variable-sum matrix games with incomplete information. These games integrated the generation product mix of real power, reactive power, and spinning reserve with the generators's capability curves as constraints. The research includes simulations of market auctions, where strategies were tested for generators with different unit constraints, costs, types of competitors, strategies, and demand levels. Studies on the capability of large hydrogen cooled synchronous generators were utilized to derive useful equations that define the exact shape of the capability curve from the intersections of the arcs defined by the centers and radial vectors of the rotor, stator, and steady-state stability limits. The available reactive reserve and spinning reserve were calculated given a

  16. Demand Response Resources for Energy and Ancillary Services (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Hummon, M.

    2014-04-01

    Demand response (DR) resources present a potentially important source of grid flexibility particularly on future systems with high penetrations of variable wind an solar power generation. However, DR in grid models is limited by data availability and modeling complexity. This presentation focuses on the co-optimization of DR resources to provide energy and ancillary services in a production cost model of the Colorado test system. We assume each DR resource can provide energy services by either shedding load or shifting its use between different times, as well as operating

  17. Brain death dilemmas and the use of ancillary testing.

    Science.gov (United States)

    Webb, Adam; Samuels, Owen

    2012-06-01

    The Uniform Determination of Death Act indicates that "an individual who has sustained either (1) irreversible cessation of circulatory and respiratory functions, or (2) irreversible cessation of all functions of the entire brain, including the brain stem, is dead," with brain death being determined based on "accepted medical standards." The AAN has published practice guidelines providing medical standards for the determination of brain death. The most recent AAN guideline update notes that "because of the deficiencies in the evidence base, clinicians must exercise considerable judgment when applying the criteria in specific circumstances" and that "ancillary tests can be used when uncertainty exists about the reliability of parts of the neurologic examination or when the apnea test cannot be performed. This article presents two cases commonly encountered in clinical practice in which the findings of the guideline-specified clinical neurologic assessment may be difficult to interpret, hampering the clinical determination of brain death. In these circumstances, ancillary testing specifically assessing for cerebral circulatory arrest may be helpful.

  18. Exogam with Vamos, Tiara and other ancillary detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lewitowicz, M.; Olivier, L.; Savajols, H.; Catford, W.; Raine, B.; Oliveira, F. de; Perru, O.; Podolyak, Z.; Redon, N.; Bouchez, E.; Simenel, C.; Stanoiu, M.; Lemmon, R.; Rubio, B.; Obertelli, A.; Cederwall, B.; Chapman, R.; Korten, W.; Rubio Barroso, B

    2003-07-01

    The aim of this workshop was to discuss the status of experiments at GANIL facility using Exogam with Vamos, Tiara and other ancillary detectors. This document gathers most of the slides that were presented at the workshop, it concerns 8 presentations: 1) the status of Spiral and Spiral-II, 2) the status of Tiara (Tiara array is used for the study of nuclear transfer reactions with radioactive beams in inverse kinematics), 3) data acquisition for the ancillary detectors, 4) the identification of gamma-ray in nuclei around Sm{sup 130}: probing the maximally deformed light rare earth region, 5) the Coulomb excitation of radioactive krypton beams (Kr{sup 76}, Kr{sup 74}), 6) the influence of weakly bound neutrons on fusion around the Coulomb barrier, 7) single particle transfer on doubly-magic Ni{sup 56}, and 8) the study of N=16 for neutron rich nuclei with Ne{sup 26}(d,p)Ne{sup 27} transfer reaction.

  19. National Ignition Facility sub-system design requirements ancillary systems SSDR 1.5.6

    Energy Technology Data Exchange (ETDEWEB)

    Spann, J.; Reed, R.; VanArsdall, P.; Bliss, E.

    1996-09-01

    This System Design Requirement document establishes the performance, design, development, and test requirements for the Ancillary Systems, which is part of the NIF Integrated Computer Control System (ICCS).

  20. Survey of U.S. Ancillary Services Markets

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Zhi [Argonne National Lab. (ANL), Argonne, IL (United States). Center for Energy, Environmental, and Economic Systems Analysis, Energy Systems Division; Levin, Todd [Argonne National Lab. (ANL), Argonne, IL (United States). Center for Energy, Environmental, and Economic Systems Analysis, Energy Systems Division; Conzelmann, Guenter [Argonne National Lab. (ANL), Argonne, IL (United States). Center for Energy, Environmental, and Economic Systems Analysis, Energy Systems Division

    2016-06-01

    In addition to providing energy to end-consumers, power system operators are also responsible for ensuring system reliability. To this end, power markets maintain an array of ancillary services to ensure that it is always possible to balance the supply and demand for energy in real-time. A subset of these ancillary services are commonly procured through market-based mechanisms: namely, Regulation, Spinning, and Non-spinning Reserves. Regulation Reserves are maintained to respond to supply/demand imbalances over short time frames, typically on the order of several seconds to one minute. Resources that provide Regulation Reserves adjust their generation or load levels in response to automatic generation control (AGC) signals provided by the system operator. Contingency reserves are maintained to provide additional generation capacity in the event that load increases substantially or supply side resources reduce their output or are taken offline. The reserves are typically segmented into two categories, 1) Spinning or Synchronized Reserves that are provided by generation units that are actively generating and have the ability to increase or decrease their output, 2) Non-spinning or Non-synchronized Reserves that are provided by generation resources that are not actively generating, but are able to start up and provide generation within a specified timeframe. Contingency reserves typically have response times on the order of ten to 30 minutes and can also be provided by demand-side resources that are capable of reducing their load. There are seven distinct power markets in the United States, each operated by a Regional Transmission Operator (RTO) or Independent System Operator (ISO) that operates the transmission system in its territory, operates markets for energy and ancillary services, and maintains system reliability. Each power market offers its own set of ancillary services, and precise definitions, requirements, and market mechanisms differ between markets

  1. Analysis of wind power ancillary services characteristics with German 250-MW wind data

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, B.

    1999-12-09

    With the increasing availability of wind power worldwide, power fluctuations have become a concern for some utilities. Under electric industry restructuring in the US, the impact of these fluctuations will be evaluated by examining provisions and costs of ancillary services for wind power. This paper analyzes wind power in the context of ancillary services, using data from a German 250 Megawatt Wind project.

  2. Effective Ancillary Services Market Designs on High Wind Power Penetration Systems: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Ela, E.; Kirby, B.; Navid, N.; Smith, J. C.

    2011-12-01

    This paper focuses on how the ancillary service market designs are implemented and how they may require changes on systems with greater penetrations of variable renewable energy suppliers, in particular wind power. Ancillary services markets have been developed in many of the restructured power system regions throughout the world. Ancillary services include the services that support the provision of energy to support power system reliability. The ancillary services markets are tied tightly to the design of the energy market and to the physics of the system and therefore careful consideration of power system economics and engineering must be considered in their design. This paper focuses on how the ancillary service market designs are implemented and how they may require changes on systems with greater penetrations of variable renewable energy suppliers, in particular wind power.

  3. Fundamental role for the KCNE4 ancillary subunit in Kv7.4 regulation of arterial tone

    DEFF Research Database (Denmark)

    Jepps, Thomas A; Carr, Georgina; Lundegaard, Pia R;

    2015-01-01

    tone by Kv7 channels. In HEK cells expressing Kv7.4, co-expression of KCNE4 increased the membrane expression of Kv7.4 and significantly altered Kv7.4 current properties. Quantitative PCR analysis of different rat arteries found that the KCNE4 isoform predominated and proximity ligation experiments......), which coincided with impaired effects of Kv7 modulators. When KCNE4 expression was reduced, less Kv7.4 expression was found in the membrane of the mesenteric artery myocytes. These data show that KCNE4 is consistently expressed in a variety of arteries, and knockdown of the expression product leads...

  4. Transactive Control and Coordination of Distributed Assets for Ancillary Services

    Energy Technology Data Exchange (ETDEWEB)

    Subbarao, Krishnappa; Fuller, Jason C.; Kalsi, Karanjit; Somani, Abhishek; Pratt, Robert G.; Widergren, Steven E.; Chassin, David P.

    2013-09-18

    The need to diversify energy supplies, the need to mitigate energy-related environmental impact, and the entry of electric vehicles in large numbers present challenges and opportunities to power system professionals. Wind and solar power provide many benefits, and to reap the benefits the resulting increased variability—forecasted as well as unforecasted—should be addressed. Demand resources are receiving increasing attention as one means of providing the grid balancing services. Control and coordination of a large number (~millions) of distributed smart grid assets requires innovative approaches. One such is transactive control and coordination (TC2)—a distributed, agent-based incentive and control system. The TC2 paradigm is to create a market system with the following characteristics: • Participation should be entirely voluntary. • The participant decides at what price s/he is willing to participate. • The bids and responses are automated. Such an approach has been developed and demonstrated by Pacific Northwest National Laboratory for energy markets. It is the purpose of this project to develop a similar approach for ancillary services. In this report, the following ancillary services are considered: • spinning reserve • ramping • regulation. These services are to be provided by the following devices: • refrigerators • water heaters • clothes dryers • variable speed drives. The important results are summarized below: The regulation signal can be divided into an energy-neutral high frequency component and a low frequency component. The high frequency component is particularly well suited for demand resources. The low frequency component, which carries energy non-neutrality, can be handled by a combination of generators and demand resources. An explicit method for such a separation is obtained from an exponentially weighted moving average filter. Causal filters (i.e., filters that process only present and past values of a signal

  5. 30 CFR 250.210 - If I conduct ancillary activities, what reporting and data/information retention requirements...

    Science.gov (United States)

    2010-07-01

    ... OPERATIONS IN THE OUTER CONTINENTAL SHELF Plans and Information Ancillary Activities § 250.210 If I conduct ancillary activities, what reporting and data/information retention requirements must I satisfy? (a... data or information obtained or derived from your ancillary activities. When applicable, MMS...

  6. 78 FR 46177 - Third-Party Provision of Ancillary Services; Accounting and Financial Reporting for New Electric...

    Science.gov (United States)

    2013-07-30

    ... Third-Party Provision of Ancillary Services; Accounting and Financial Reporting for New Electric Storage...-Party Provision of Ancillary Services; Accounting and Financial Reporting for New Electric Storage... services. \\6\\ Third-Party Provision of Ancillary Services; Accounting and Financial Reporting for...

  7. 77 FR 40413 - Third-Party Provision of Ancillary Services; Accounting and Financial Reporting for New Electric...

    Science.gov (United States)

    2012-07-09

    ... 101 Third-Party Provision of Ancillary Services; Accounting and Financial Reporting for New Electric... 101 Third-Party Provision of Ancillary Services; Accounting and Financial Reporting for New Electric... jurisdiction. \\2\\ Third-Party Provision of Ancillary Services; Accounting and Financial Reporting for...

  8. Exploiting ancillary services from distributed generation - perspectives for the Danish power system

    DEFF Research Database (Denmark)

    Nyeng, Preben; Pedersen, Knud Ole Helgesen; Østergaard, Jacob

    2007-01-01

    The share of the electric power production originating from distributed energy resources has rapidly increased during the recent past. However when it comes to ancillary services necessary to ensure the stability and appropriate operation of the power system, the distributed energy resources take...... a very passive role. This paper outlines suggestions on how to activate the potential of ancillary services from distributed energy resources, thereby exploiting their ability to contribute to power system operation. Furthermore, methods for integrating the ancillary service delivery into a deregulated...... power system are proposed and evaluated....

  9. Capabilities and costs for ancillary services provision by wind power plants. Deliverable D 3.1

    DEFF Research Database (Denmark)

    Faiella, Mariano; Hennig, Tobias; Cutululis, Nicolaos Antonio;

    This report is the deliverable of the third work package of the REserviceS project and describes the technical options and related costs for the provision of ancillary services specifically from wind energy technologies. It is focused on the set of ancillary services defined in the previous work...... package 2, shown in table 1 below. The information from this deliverable will be used as input to the case studies in subsequent work packages, which are expected to provide additional insights to the actual provision of ancillary services in transmission and distribution networks....

  10. Survey of U.S. Ancillary Services Markets

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Zhi; Levin, Todd; Conzelmann, Guenter

    2016-06-01

    In addition to providing energy to end-consumers, power system operators are also responsible for ensuring system reliability. To this end, power markets maintain an array of ancillary services to ensure that it is always possible to balance the supply and demand for energy in real-time. A subset of these ancillary services are commonly procured through market-based mechanisms: namely, Regulation, Spinning, and Non-spinning Reserves. Regulation Reserves are maintained to respond to supply/demand imbalances over short time frames, typically on the order of several seconds to one minute. Resources that provide Regulation Reserves adjust their generation or load levels in response to automatic generation control (AGC) signals provided by the system operator. Contingency reserves are maintained to provide additional generation capacity in the event that load increases substantially or supply side resources reduce their output or are taken offline. The reserves are typically segmented into two categories, 1) Spinning or Synchronized Reserves that are provided by generation units that are actively generating and have the ability to increase or decrease their output, 2) Non-spinning or Non-synchronized Reserves that are provided by generation resources that are not actively generating, but are able to start up and provide generation within a specified timeframe. Contingency reserves typically have response times on the order of ten to 30 minutes and can also be provided by demand-side resources that are capable of reducing their load. There are seven distinct power markets in the United States, each operated by a Regional Transmission Operator (RTO) or Independent System Operator (ISO) that operates the transmission system in its territory, operates markets for energy and ancillary services, and maintains system reliability. Each power market offers its own set of ancillary services, and precise definitions, requirements, and market mechanisms differ between markets

  11. Commercial Building Loads Providing Ancillary Services in PJM

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, Jason; Kiliccote, Sila; Boch, Jim; Chen, Jonathan; Nawy, Robert

    2014-06-27

    The adoption of low carbon energy technologies such as variable renewable energy and electric vehicles, coupled with the efficacy of energy efficiency to reduce traditional base load has increased the uncertainty inherent in the net load shape. Handling this variability with slower, traditional resources leads to inefficient system dispatch, and in some cases may compromise reliability. Grid operators are looking to future energy technologies, such as automated demand response (DR), to provide capacity-based reliability services as the need for these services increase. While DR resources are expected to have the flexibility characteristics operators are looking for, demonstrations are necessary to build confidence in their capabilities. Additionally, building owners are uncertain of the monetary value and operational burden of providing these services. To address this, the present study demonstrates the ability of demand response resources providing two ancillary services in the PJM territory, synchronous reserve and regulation, using an OpenADR 2.0b signaling architecture. The loads under control include HVAC and lighting at a big box retail store and variable frequency fan loads. The study examines performance characteristics of the resource: the speed of response, communications latencies in the architecture, and accuracy of response. It also examines the frequency and duration of events and the value in the marketplace which can be used to examine if the opportunity is sufficient to entice building owners to participate.

  12. Utilization of Ancillary Data Sets for SMAP Algorithm Development and Product Generation

    Science.gov (United States)

    ONeill, P.; Podest, E.; Njoku, E.

    2011-01-01

    Algorithms being developed for the Soil Moisture Active Passive (SMAP) mission require a variety of both static and ancillary data. The selection of the most appropriate source for each ancillary data parameter is driven by a number of considerations, including accuracy, latency, availability, and consistency across all SMAP products and with SMOS (Soil Moisture Ocean Salinity). It is anticipated that initial selection of all ancillary datasets, which are needed for ongoing algorithm development activities on the SMAP algorithm testbed at JPL, will be completed within the year. These datasets will be updated as new or improved sources become available, and all selections and changes will be documented for the benefit of the user community. Wise choices in ancillary data will help to enable SMAP to provide new global measurements of soil moisture and freeze/thaw state at the targeted accuracy necessary to tackle hydrologically-relevant societal issues.

  13. EX1504L2 Dive17 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  14. EX1504L2 Dive03 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  15. EX1504L4 Dive12 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  16. EX1504L4 Dive07 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  17. EX1504L2 Dive02 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  18. EX1504L4 Dive01 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  19. EX1504L2 Dive08 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  20. EX1504L2 Dive09 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  1. EX1504L2 Dive15 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  2. EX1504L2 Dive01 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  3. EX1504L4 Dive04 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  4. EX1504L4 Dive11 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  5. EX1504L2 Dive04 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  6. EX1504L4 Dive13 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  7. EX1504L4 Dive09 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  8. EX1504L2 Dive13 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  9. EX1504L2 Dive07 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  10. EX1504L4 Dive05 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  11. EX1504L4 Dive08 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  12. EX1504L2 Dive06 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  13. EX1504L2 Dive14 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  14. EX1504L4 Dive02 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  15. EX1504L3 Dive06 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L3: CAPSTONE Leg III:...

  16. EX1504L2 Dive10 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  17. EX1504L3 Dive02 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L3: CAPSTONE Leg III:...

  18. EX1504L2 Dive16 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  19. EX1504L2 Dive05 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  20. EX1504L3 Dive04 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L3: CAPSTONE Leg III:...

  1. EX1504L3 Dive07 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L3: CAPSTONE Leg III:...

  2. EX1504L4 Dive10 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  3. EX1504L4 Dive03 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  4. EX1504L3 Dive05 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L3: CAPSTONE Leg III:...

  5. EX1504L4 Dive06 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  6. EX1504L2 Dive12 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  7. EX1504L2 Dive11 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  8. EX1504L2 Dive18 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  9. EX1504L3 Dive03 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L3: CAPSTONE Leg III:...

  10. Technical and economic aspects of ancillary services markets in the electric power industry: an international comparison

    Energy Technology Data Exchange (ETDEWEB)

    Raineri, R. [Ingenieria Industrial y de Sistema e Ingenieria Electrica, Pontificia Universidad Catolica de Chile, Casilla 306, Correo 22, Santiago (Chile)]. E-mail: rraineri@ing.puc.cl; Rios, S. [Ingenieria Industrial y de Sistema e Ingenieria Electrica, Pontificia Universidad Catolica de Chile, Casilla 306, Correo 22, Santiago (Chile); Schiele, D. [Ingenieria Industrial y de Sistema e Ingenieria Electrica, Pontificia Universidad Catolica de Chile, Casilla 306, Correo 22, Santiago (Chile)

    2006-09-15

    We present a comparative analysis of technical and economic aspects of ancillary services on the markets of England and Wales, Nordic Countries, California, Argentina, Australia and Spain, comparing the services of voltage control, frequency regulation and system restoration. All the analyzed markets rely on the existence of an administrator of ancillary services, function that leads to the figure of the system operator. Among the services analyzed, the mandatory nature of voltage control and primary frequency regulation stands out, being both the ancillary services with the higher market price and the shortest period of time requirements. In general, the recognized costs of the services correspond to investments operation, maintenance, and opportunity costs. In the provision of these ancillary services, there are no clear preferences for a particular resource allocation mechanism, where mandatory provision, auctions, competitive offers and different time length bilateral contracts are combined.

  11. Ocean Surface Topography Mission (OSTM) /Jason-2: Ancillary Files (NODC Accession 0044982)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This accession contains the data descriptions for the OSTM/Jason-2 Ancillary data files, which is served through the NOAA/NESDIS Comprehensive Large Array-data...

  12. Ancillary Services for the European Grid with High Shares of Wind and Solar Power

    DEFF Research Database (Denmark)

    Van Hulle, Frans; Holttinen, Hannele; Kiviluoma, Juha

    2012-01-01

    With significantly increasing share of variable renewable power generation like wind and solar PV, the need in the power system for ancillary services supporting the network frequency, voltage, etc. changes. Turning this issue around, market opportunities will emerge for wind and solar PV...... technology to deliver such grid services. In the European power system, adequate market mechanisms need to be developed to ensure that there will be an efficient trading of these services. For that purpose a range of (economic) characteristics of wind (and solar) power as providers of grid services need......) conceptually analyzing system needs for ancillary services and at assessing the technical aspects of and cost of delivering these services by solar PV and wind power, in scenarios of high renewable penetration. (2) Investigation of the need for ancillary services in typical transmission and distribution...

  13. Entanglement Capabilities of Non-local Hamiltonians with Maximally Entangled Ancillary Particles

    Institute of Scientific and Technical Information of China (English)

    YE Peng; ZHENG Yizhuang

    2004-01-01

    @@ The entanglement capacity of non-local two-qubit Hamiltonians with maximally entangled ancillary particles are investigated.We gain a complete expression of entanglement capacity and show that the maximal entanglement capacity Γmax of a non-local Hamiltonian with ancillary particles will be never less than the maximal entanglement capacity Γ*max of the non-local Hamiltonian without ancillary particles.By defining relative entanglement rate η=Γmax /Γ*max (Γmax, Γ*max are maximal entanglement rate with and without ancillas respectively), we find the range of the values of relative entanglement rate is 1η1.3220.

  14. The ancillary benefits and costs of climate change mitigation: a conceptual framework

    Energy Technology Data Exchange (ETDEWEB)

    Krupnick, A.; Burtraw, D.; Markandya, A. [Resources for the Future, Washington, DC (USA)

    2000-07-01

    The paper concentrates on what the authors consider the most important in identifying and measuring ancillary benefits and costs in order to inform national-level policy analysis regarding mitigation of greenhouse gases. It considers ancillary benefits in the context of standard welfare economic theory, examines various types of claimed benefits to determine when they are valid, identifies factors that could change the benefit levels, examines the possibilities that economic behaviour could bring ancillary costs rather than benefits, and pays special attention to these issues in a developing country context. It mentions that reducing output of coal-based electricity by, for example, substituting nuclear or hydroelectric power could introduce health risks and create negative externalities to river ecosystems. Reduction in electricity use could, in developing countries, lead to an increase in indoor air pollution. 56 refs., 2 figs., 3 tabs.

  15. Loads Providing Ancillary Services: Review of InternationalExperience-- Technical Appendix: Market Descriptions

    Energy Technology Data Exchange (ETDEWEB)

    Grayson Heffner, Charles Goldman, Kintner-Meyer, M; Kirby, Brendan

    2007-05-01

    In this study, we examine the arrangements for andexperiences of end-use loads providing ancillary services (AS) in fiveelectricity markets: Australia, the United Kingdom (UK), the Nordicmarket, and the ERCOT and PJM markets in the United States. Our objectivein undertaking this review of international experience was to identifyspecific approaches or market designs that have enabled customer loads toeffectively deliver various ancillary services (AS) products. We hopethat this report will contribute to the ongoing discussion in the U.S.and elsewhere regarding what institutional and technical developments areneeded to ensure that customer loads can meaningfully participate in allwholesale electricity markets.

  16. Optimal Sizing and Allocation of Residential Photovoltaic Panels in a Distribution Network for Ancillary Services Application

    DEFF Research Database (Denmark)

    Kordheili, Reza Ahmadi; Pourmousavi, Ali; Pillai, Jayakrishnan Radhakrishna

    2014-01-01

    Tremendous penetration of renewable energy in electric networks, despite its valuable opportunities, such as balancing reserve and ancillary service, has raised concerns for network operators. Such concern stems from grid operating conditions. Such huge penetration can lead to violation in the grid...... requirements, such as voltage and current limits. This paper proposes an optimization method for determining the number of photovoltaic (PV) panels together with their arrangement in the grid in order to maximize ancillary service, without violating grid operation limits. The proposed optimization method...... the grid requirements within standard operating limits....

  17. Industrial Demand Management Providing Ancillary Services to the Distribution Grid: Experimental Verification

    DEFF Research Database (Denmark)

    Rahnama, Samira; Bendtsen, Jan Dimon; Lyhne, Casper

    2017-01-01

    A prominent feature of the future smart grid is the active participation of the consumer side in ancillary service provision. Grid operators procure ancillary services, including regulating power, voltage control, frequency control, and so on, to ensure safe, reliable, and high-quality electricity...... delivery. Consumers' involvement requires new entities and infrastructure. A so-called aggregator has been introduced as a new player to manage the services that are offered by the consumption units. This paper describes an industrial scale experimental setup for evaluating a particular type of aggregator...

  18. 29 CFR 2550.408b-6 - Statutory exemption for ancillary services by a bank or similar financial institution.

    Science.gov (United States)

    2010-07-01

    ....408b-6 Statutory exemption for ancillary services by a bank or similar financial institution. (a) In... service is consistent with sound banking and financial practice, as determined by Federal or State... 29 Labor 9 2010-07-01 2010-07-01 false Statutory exemption for ancillary services by a bank...

  19. Use of LANDSAT-7 ETM+ with ancillary data for soil salinity mapping in northeast Thailand

    Science.gov (United States)

    Katawatin, Roengsak; Kotrapat, Wilaiwan

    2005-04-01

    Soil salinity is a major environmental constraint in Northeast Thailand. Sustainable land use and management in this region require careful mapping of the salinity status. This study was conducted to investigate performances of some digital classification techniques for soil salinity mapping in the Northeast. The techniques investigated were based on the use of LANDSAT-7 ETM+ with different combinations of three kinds of ancillary data (i.e., topography, geology, and underground water quality). In this study, the Maximum Likelihood classification method was employed. Statistics including KAPPA analysis and Z-statistic, overall accuracy, producer's accuracy, and user's accuracy, were used as the bases for assessments of mapping accuracies and, in turn, performances of the classification techniques. Results have shown that the use of ETM+ data bands 4,5 and 7, with the combination of all three kinds of the ancillary data yielded the most accurate soil salinity map with 83.6 % overall accuracy. The same subset of ETM+ data when used with any combination of two kinds of the ancillary data could serve as well. Other classification techniques yielded significantly less accurate results. It was, therefore, concluded that techniques based on the use of the selected ETM+ data subset with combinations of two or three kinds of the ancillary data were promising.

  20. Technical Feasibility of Ancillary Services provided by ReGen Plants

    DEFF Research Database (Denmark)

    Altin, Müfit; Han, Xue; Hansen, Anca Daniela;

    This report is the first deliverable in WP1 in the project “Ancillary services from renewable power plants” (RePlan). RePlan is funded as PSO project 2015 no. 12347 by the Danish PSO-programme ForskEL, which is administered by Energinet.DK. RePlan is carried out in collaboration between DTU Wind ...

  1. Ancillary Frequency Control of Direct Drive Full-Scale Converter Based Wind Power Plants

    DEFF Research Database (Denmark)

    Hu, Weihao; Su, Chi; Fang, Jiakun;

    2013-01-01

    This paper presents a simulation model of a wind power plant based on a MW-level variable speed wind turbine with a full-scale back-to-back power converter developed in the simulation tool of DIgSILENT Power Factory. Three different kinds of ancillary frequency control strategies, namely inertia ...

  2. Provision of enhanced ancillary services from wind power plants - Examples and challenges

    DEFF Research Database (Denmark)

    Hansen, Anca Daniela; Altin, Müfit; Iov, Florin

    2016-01-01

    Emphasis in this article is on the power system impact of wind power plants capability to provide enhanced ancillary services, i.e. temporary frequency response (TFR) and power oscillation damping (POD). The main objective of the article is to analyze and justify the challenges in the use of TFR ...

  3. Differentiation of Moraxella nonliquefaciens, M. lacunata, and M. bovis by using multilocus enzyme electrophoresis and hybridization with pilin-specific DNA probes.

    Science.gov (United States)

    Tønjum, T; Caugant, D A; Bøvre, K

    1992-12-01

    Genetic relationships among strains of Moraxella nonliquefaciens, M. lacunata, and M. bovis were studied by using multilocus enzyme electrophoresis and DNA-DNA hybridization. The 74 isolates analyzed for electrophoretic variation at 12 enzyme loci were assigned to 59 multilocus genotypes. The multilocus genotypes were grouped in four major clusters, one representing strains of M. nonliquefaciens, two representing strains of M. lacunata, and one comprising strains of M. bovis and the single strain of M. equi analyzed. DNA-DNA hybridization with total genomic probes also revealed four major distinctive entities that corresponded to those identified by multilocus enzyme electrophoresis. The two distinct clusters recognized among the M. lacunata strains apparently corresponded to the species previously designated M. lacunata and M. liquefaciens. Distinction of the four entities was improved by hybridization with polymerase chain reaction products of nonconserved parts of pilin genes as DNA probes. With these polymerase chain reaction probes, new isolates of M. nonliquefaciens, M. lacunata, M. liquefaciens, and M. bovis can be identified easily by hybridization.

  4. Ancillary services: technical specifications, system needs and costs. Deliverable D 2.2

    DEFF Research Database (Denmark)

    Holttinen, Hannele; Cutululis, Nicolaos Antonio; Gubina, Andrej;

    2012-01-01

    In this report, different ancillary services are described and a table listing main services is presented. While Chapter 2 is describing the services from (renewable) generators point of view, Chapter 3 is considering future system needs for services with increased wind and solar penetration. The....... The table will be used as a starting point in the REServiceS project to see how much these services would cost when provided from wind/PV (WP3/4), and how often these services would be used in systems with higher penetrations of wind and solar (WP5/6).......In this report, different ancillary services are described and a table listing main services is presented. While Chapter 2 is describing the services from (renewable) generators point of view, Chapter 3 is considering future system needs for services with increased wind and solar penetration...

  5. Coordinated Control Scheme for Ancillary Services from Offshore Wind Power Plants to AC and DC Grids

    DEFF Research Database (Denmark)

    Sakamuri, Jayachandra N.; Altin, Müfit; Hansen, Anca Daniela;

    2016-01-01

    This paper proposes a new approach of providing ancillary services to AC and DC grids from offshore wind power plants (OWPPs), connected through multi-terminal HVDC network. A coordinated control scheme where OWPP’s AC grid frequency modulated according to DC grid voltage variations is used...... to detect and provide the ancillary service requirements of both AC and DC grids, is proposed in this paper. In particular, control strategies for onshore frequency control, fault ridethrough support in the onshore grid, and DC grid voltage control are considered. The proposed control scheme involves only...... local measurements and therefore avoids the need of communication infrastructure otherwise required for communication based control, and thus increases the reliability of the control system. The effectiveness of the proposed control scheme is demonstrated on a MTDC connected wind power system developed...

  6. Ancillary qubit spectroscopy of vacua in cavity and circuit quantum electrodynamics.

    Science.gov (United States)

    Lolli, Jared; Baksic, Alexandre; Nagy, David; Manucharyan, Vladimir E; Ciuti, Cristiano

    2015-05-01

    We investigate theoretically how the spectroscopy of an ancillary qubit can probe cavity (circuit) QED ground states containing photons. We consider three classes of systems (Dicke, Tavis-Cummings, and Hopfield-like models), where nontrivial vacua are the result of ultrastrong coupling between N two-level systems and a single-mode bosonic field. An ancillary qubit detuned with respect to the boson frequency is shown to reveal distinct spectral signatures depending on the type of vacua. In particular, the Lamb shift of the ancilla is sensitive to both ground state photon population and correlations. Backaction of the ancilla on the cavity ground state is investigated, taking into account the dissipation via a consistent master equation for the ultrastrong coupling regime. The conditions for high-fidelity measurements are determined.

  7. Influence of Wind Plant Ancillary Frequency Control on System Small Signal Stability

    DEFF Research Database (Denmark)

    Su, Chi; Chen, Zhe

    2012-01-01

    Since large-scale wind farms are increasingly connected to modern power grids, the transmission system operators put more requirements as part of the grid codes on the integration of wind farms. System frequency control which is normally provided by conventional synchronous generators becomes...... a common requirement to wind farms. This ancillary frequency control provided by wind farms could have some influence on the system small signal stability. This paper implements an ancillary frequency control strategy on a directdrive- full-convertor-based wind farm and studies its influence on the damping...... ratio values of the dominant oscillation modes within the connected power system. All the calculations and simulations are conducted in DIgSILENT PowerFactory 14.0....

  8. Influence of Wind Plant Ancillary Voltage Control on System Small Signal Stability

    DEFF Research Database (Denmark)

    Su, Chi; Chen, Zhe

    2012-01-01

    As a common tendency, large-scale wind farms are increasingly connected to the transmission system of modern power grids. This introduces some new challenges to the connected power systems, and the transmission system operators (TSOs) have to put some new requirements as part of the grid codes...... on the integration of wind farms. One common requirement to wind farms is the function of system voltage control which can be implemented in the grid-side convertor controller of a variable speed wind turbine. This ancillary voltage control provided by wind farms could have some influence on the system small signal...... stability. This paper implements an ancillary voltage control strategy on a direct-drive-full-convertor-based wind farm and studies its influence on the damping ratio values of the dominant oscillation mode within the connected power system. All the calculations and simulations are conducted in DIg...

  9. Market and policy barriers for demand response providing ancillary services in U.S. markets

    Energy Technology Data Exchange (ETDEWEB)

    Cappers, Peter [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); MacDonald, Jason [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Goldman, Charles [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

    2013-03-01

    This study provides an examination of various market and policy barriers to demand response providing ancillary services in both ISO/RTO and non-ISO/RTO regions, especially at the program provider level. It is useful to classify barriers in order to create a holistic understanding and identify parties that could be responsible for their removal. This study develops a typology of barriers focusing on smaller customers that must rely on a program provider (i.e., electric investor owned utility or IOU, ARC) to create an aggregated DR resource in order to bring ancillary services to the balancing authority. The barriers were identified through examinations of regulatory structures, market environments, and product offerings; and discussions with industry stakeholders and regulators. In order to help illustrate the differences in barriers among various wholesale market designs and their constituent retail environments, four regions were chosen to use as case studies: Colorado, Texas, Wisconsin, and New Jersey.

  10. VOLTTRON-Based System for Providing Ancillary Services with Residential Building Loads

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Xin

    2016-07-01

    Ancillary services entail controlled modulation of building equipment to maintain a stable balance of generation and load in the power system. Ancillary services include frequency regulation and contingency reserves, whose acting time ranges from several seconds to several minutes. Many pilot studies have been implemented to use industrial loads to provide ancillary services, and some have explored services from commercial building loads or electric vehicle charging loads. Residential loads, such as space conditioning and water heating, represent a largely untapped resource for providing ancillary services. The residential building sector accounts for a significant fraction of the total electricity use in the United States. Many loads in residential buildings are flexible and could potentially be curtailed or shifted at the request of the grid. However, there are many barriers that prevent residential loads being widely used for ancillary services. One of the major technical barriers is the lack of communication capabilities between end-use devices and the grid. End-use devices need to be able to receive the automatic generation control (AGC) signal from the grid operator and supply certain types of telemetry to verify response. With the advance of consumer electronics, communication-enabled, or 'connected,' residential equipment has emerged to overcome the communication barrier. However, these end-use devices have introduced a new interoperability challenge due to the existence of numerous standards and communication protocols among different end devices. In this paper, we present a VOLTTRON-based system that overcomes these technical challenges and provides ancillary services with residential loads. VOLTTRON is an open-source control and sensing platform for building energy management, facilitating interoperability solutions for end devices. We have developed drivers to communicate and control different types of end devices through standard

  11. Nuclear structure at high spin using multidetector gamma array and ancillary detectors

    Indian Academy of Sciences (India)

    S Muralithar

    2014-04-01

    A multidetector gamma array (GDA), for studying nuclear structure was built with ancillary devices namely gamma multiplicity filter and charged particle detector array. This facility was designed for in-beam gamma spectroscopy measurements in fusion evaporation reactions at Inter-University Accelerator Centre, New Delhi. Description of the facility and in-beam performance with two experimental studies done are presented. This array was used in a number of nuclear spectroscopic and reaction investigations.

  12. CO{sub 2} mitigation costs and ancillary benefits in the Nordic countries, the UK and Ireland: A survey

    Energy Technology Data Exchange (ETDEWEB)

    Kverndokk, Snorre; Rosendahl, Knut Einar

    2000-07-01

    This paper provides a survey of top-down modelling studies on mitigation costs and ancillary benefits in the Nordic countries, the UK and Ireland. Special emphasis is put on results concerning revenue recycling, double dividend, distributional effects and ancillary benefits. According to the papers surveyed, modest emissions restrictions as those given by the Kyoto Protocol, can be met without substantial costs for the countries studied. (Author)

  13. Integrating TM and Ancillary Geographical Data with Classification Trees for Land Cover Classification of Marsh Area

    Institute of Scientific and Technical Information of China (English)

    NA Xiaodong; ZHANG Shuqing; ZHANG Huaiqing; LI Xiaofeng; YU Huan; LIU Chunyue

    2009-01-01

    The main objective of this research is to determine the capacity of land cover classification combining spectral and textural features of Landsat TM imagery with ancillary geographical data in wetlands of the Sanjiang Plain, Heilongjiang Province, China. Semi-variograms and Z-test value were calculated to assess the separability of grey-level co-occurrence texture measures to maximize the difference between land cover types. The degree of spatial autocorrelation showed that window sizes of 3×3 pixels and 11×11 pixels were most appropriate for Landsat TM image texture calculations. The texture analysis showed that co-occurrence entropy, dissimilarity, and variance texture measures, derived from the Landsat TM spectrum bands and vegetation indices provided the most significant statistical differentiation between land cover types. Subsequently, a Classification and Regression Tree (CART) algorithm was applied to three different combinations of predictors: 1) TM imagery alone (TM-only); 2) TM imagery plus image texture (TM+TXT model); and 3) all predictors including TM imagery, image texture and additional ancillary GIS information (TM+TXT+GIS model). Compared with traditional Maximum Likelihood Classification (MLC) supervised classification, three classification trees predictive models reduced the overall error rate significantly. Image texture measures and ancillary geographical variables depressed the speckle noise effectively and reduced classification error rate of marsh obviously. For classification trees model making use of all available predictors, omission error rate was 12.90% and commission error rate was 10.99% for marsh. The developed method is portable, relatively easy to implement and should be applicable in other settings and over larger extents.

  14. Molecular Structure Laboratory. Fourier Transform Nuclear Magnetic Resonance (FTNMR) Spectrometer and Ancillary Instrumentation at SUNY Geneseo

    Energy Technology Data Exchange (ETDEWEB)

    Geiger, David K [State Univ. of New York (SUNY), Geneseo, NY (United States)

    2015-12-31

    An Agilent 400-MR nuclear magnetic resonance (NMR) spectrometer and ancillary equipment were purchased, which are being used for molecular structure elucidation.  The instrumentation is housed in a pre-existing facility designed specifically for its use. This instrument package is being used to expand the research and educational efforts of the faculty and students at SUNY-Geneseo and is made available to neighboring educational institutions and business concerns.  Funds were also used for training of College personnel, maintenance of the instrumentation, and installation of the equipment.

  15. Role of the Rubisco Small Subunit

    Energy Technology Data Exchange (ETDEWEB)

    Spreitzer, Robert Joseph [Univ. of Nebraska, Lincoln, NE (United States)

    2016-11-05

    Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) catalyzes the rate-limiting step of CO2 fixation in photosynthesis. However, it is a slow enzyme, and O2 competes with CO2 at the active site. Oxygenation initiates the photorespiratory pathway, which also results in the loss of CO2. If carboxylation could be increased or oxygenation decreased, an increase in net CO2 fixation would be realized. Because Rubisco provides the primary means by which carbon enters all life on earth, there is much interest in engineering Rubisco to increase the production of food and renewable energy. Rubisco is located in the chloroplasts of plants, and it is comprised of two subunits. Much is known about the chloroplast-gene-encoded large subunit (rbcL gene), which contains the active site, but much less is known about the role of the nuclear-gene-encoded small subunit in Rubisco function (rbcS gene). Both subunits are coded by multiple genes in plants, which makes genetic engineering difficult. In the eukaryotic, green alga Chlamydomonas reinhardtii, it has been possible to eliminate all the Rubisco genes. These Rubisco-less mutants can be maintained by providing acetate as an alternative carbon source. In this project, focus has been placed on determining whether the small subunit might be a better genetic-engineering target for improving Rubisco. Analysis of a variable-loop structure (βA-βB loop) of the small subunit by genetic selection, directed mutagenesis, and construction of chimeras has shown that the small subunit can influence CO2/O2 specificity. X-ray crystal structures of engineered chimeric-loop enzymes have indicated that additional residues and regions of the small subunit may also contribute to Rubisco function. Structural dynamics of the small-subunit carboxyl terminus was also investigated. Alanine-scanning mutagenesis of the most-conserved small-subunit residues has identified a

  16. Role of the Emp Pilus Subunits of Enterococcus faecium in Biofilm Formation, Adherence to Host Extracellular Matrix Components, and Experimental Infection.

    Science.gov (United States)

    Montealegre, Maria Camila; Singh, Kavindra V; Somarajan, Sudha R; Yadav, Puja; Chang, Chungyu; Spencer, Robert; Sillanpää, Jouko; Ton-That, Hung; Murray, Barbara E

    2016-05-01

    Enterococcus faecium is an important cause of hospital-associated infections, including urinary tract infections (UTIs), bacteremia, and infective endocarditis. Pili have been shown to play a role in the pathogenesis of Gram-positive bacteria, including E. faecium We previously demonstrated that a nonpiliated ΔempABC::cat derivative of E. faecium TX82 was attenuated in biofilm formation and in a UTI model. Here, we studied the contributions of the individual pilus subunits EmpA, EmpB, and EmpC to pilus architecture, biofilm formation, adherence to extracellular matrix (ECM) proteins, and infection. We identified EmpA as the tip of the pili and found that deletion of empA reduced biofilm formation to the same level as deletion of the empABC operon, a phenotype that was restored by reconstituting in situ the empA gene. Deletion of empB also caused a reduction in biofilm, while EmpC was found to be dispensable. Significant reductions in adherence to fibrinogen and collagen type I were observed with deletion of empA and empB, while deletion of empC had no adherence defect. Furthermore, we showed that each deletion mutant was significantly attenuated in comparison to the isogenic parental strain, TX82, in a mixed-inoculum UTI model (P Emp pilins are important for E. faecium to cause infection in the urinary tract.

  17. Risk capital allocation with autonomous subunits

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Smilgins, Aleksandrs

    2016-01-01

    Risk capital allocation problems have been widely discussed in the academic literature. We consider a set of independent subunits collaborating in order to reduce risk: that is, when subunit portfolios are merged a diversification benefit arises and the risk of the group as a whole is smaller than...

  18. 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....

  19. Open Automated Demand Response Communications in Demand Response for Wholesale Ancillary Services

    Energy Technology Data Exchange (ETDEWEB)

    Kiliccote, Sila; Piette, Mary Ann; Ghatikar, Girish; Koch, Ed; Hennage, Dan; Hernandez, John; Chiu, Albert; Sezgen, Osman; Goodin, John

    2009-11-06

    The Pacific Gas and Electric Company (PG&E) is conducting a pilot program to investigate the technical feasibility of bidding certain demand response (DR) resources into the California Independent System Operator's (CAISO) day-ahead market for ancillary services nonspinning reserve. Three facilities, a retail store, a local government office building, and a bakery, are recruited into the pilot program. For each facility, hourly demand, and load curtailment potential are forecasted two days ahead and submitted to the CAISO the day before the operation as an available resource. These DR resources are optimized against all other generation resources in the CAISO ancillary service. Each facility is equipped with four-second real time telemetry equipment to ensure resource accountability and visibility to CAISO operators. When CAISO requests DR resources, PG&E's OpenADR (Open Automated DR) communications infrastructure is utilized to deliver DR signals to the facilities energy management and control systems (EMCS). The pre-programmed DR strategies are triggered without a human in the loop. This paper describes the automated system architecture and the flow of information to trigger and monitor the performance of the DR events. We outline the DR strategies at each of the participating facilities. At one site a real time electric measurement feedback loop is implemented to assure the delivery of CAISO dispatched demand reductions. Finally, we present results from each of the facilities and discuss findings.

  20. A hybrid PSO technique for procuring VAR ancillary service in the deregulated electricity markets

    Energy Technology Data Exchange (ETDEWEB)

    El-Araby, E.E. [Department of Electrical Engineering, Suez Canal University (Egypt); Yorino, Naoto [Department of Artificial Complex Systems Engineering, Hiroshima University (Japan)

    2010-07-15

    This paper develops a new market-based technique for acquiring VAR ancillary service in the electricity market. The main objective of the developed market is to enable transmission operator ''TO'' to procure VAR service in a long term contract from the critical VAR providers that satisfy minimum VAR service payment while maintaining system security. Reactive power control problem for voltage stability is introduced into the VAR market problem in an explicit manner for normal and emergency states. An integration of particle swarm optimization ''PSO'' is presented with successive linear programming ''SLP'' for dealing with the VAR ancillary service problem. The problem is formulated as a large-scale nonlinear constrained optimization problem with a non-differentiable objective function representing VAR payment and operational costs. This type of problem is hard to be treated straightforwardly by the classical optimization methods. Therefore, we propose here a two-layer hybrid PSO/SLP approach, which is suited for carrying out the difficulties associated with non-differentiable and discontinuous objective functions. The proposed method has been examined on the standard IEEE 57 bus-system and compared with GA/SLP method to demonstrate its capability. (author)

  1. Market and Policy Barriers for Demand Response Providing Ancillary Services in U.S. Markets

    Energy Technology Data Exchange (ETDEWEB)

    Cappers, Peter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); MacDonald, Jason [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Goldman, Charles [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2013-03-01

    In this study, we attempt to provide a comprehensive examination of various market and policy barriers to demand response providing ancillary services in both ISO/RTO and non-ISO/RTO regions, especially at the program provider level. It is useful to classify barriers in order to create a holistic understanding and identify parties that could be responsible for their removal. This study develops a typology of barriers focusing on smaller customers that must rely on a program provider (i.e., electric investor owned utility or IOU, ARC) to create an aggregated DR resource in order to bring ancillary services to the balancing authority.ii The barriers were identified through examinations of regulatory structures, market environments, and product offerings; and discussions with industry stakeholders and regulators. In order to help illustrate the differences in barriers among various wholesale market designs and their constituent retail environments, four regions were chosen to use as case studies: Colorado, Texas, Wisconsin, and New Jersey. We highlight the experience in each area as it relates to the identified barriers.

  2. Complementation for an essential ancillary non-structural protein function across parvovirus genera.

    Science.gov (United States)

    Mihaylov, Ivailo S; Cotmore, Susan F; Tattersall, Peter

    2014-11-01

    Parvoviruses encode a small number of ancillary proteins that differ substantially between genera. Within the genus Protoparvovirus, minute virus of mice (MVM) encodes three isoforms of its ancillary protein NS2, while human bocavirus 1 (HBoV1), in the genus Bocaparvovirus, encodes an NP1 protein that is unrelated in primary sequence to MVM NS2. To search for functional overlap between NS2 and NP1, we generated murine A9 cell populations that inducibly express HBoV1 NP1. These were used to test whether NP1 expression could complement specific defects resulting from depletion of MVM NS2 isoforms. NP1 induction had little impact on cell viability or cell cycle progression in uninfected cells, and was unable to complement late defects in MVM virion production associated with low NS2 levels. However, NP1 did relocate to MVM replication centers, and supports both the normal expansion of these foci and overcomes the early paralysis of DNA replication in NS2-null infections.

  3. Analysis of the Impact of Wind Power Participating in Both Energy and Ancillary Services Markets – The Danish Case

    DEFF Research Database (Denmark)

    Soares, Tiago; Morais, Hugo; Pinson, Pierre

    2014-01-01

    with appropriate levels of security and reliability . The participation of wind f arms i n ancillary service market s ought to rely on market designs and offering strategies that satisfy power system needs, as well as their operating characteristics . Here we evaluate the system impact of different offering...... strategies that wind farms employ on ene rgy and ancillary service market. A lready proposed Proportional Wind Reserve Strategy (PWRS) and a Continuo us Wind Reserve Strategy (CWRS) are used to determine the amount of available power for ancillary services. A case study based on real and recent dat...... a for Denmark allows evaluating impact on market prices, wind farms’ revenue, as well as impact on power system reliability ....

  4. Acetylcholine receptor subunit and P-glycoprotein transcription patterns in levamisole-susceptible and -resistant Haemonchus contortus

    Science.gov (United States)

    Sarai, Ranbir S.; Kopp, Steven R.; Coleman, Glen T.; Kotze, Andrew C.

    2013-01-01

    The mechanism of resistance to the anthelmintic levamisole in parasitic nematodes is poorly understood, although there is some evidence implicating changes in expression of nicotinic acetylcholine receptor (nAChR) subunit genes. Hence, in order to define levamisole resistance mechanisms in some Australian field-derived isolates of Haemonchus contortus we examined gene expression patterns and SNPs in nAChR subunit genes, as well as expression levels for P-glycoprotein (P-gp) and receptor ancillary protein genes, in various life stages of one levamisole-sensitive and three levamisole-resistant isolates of this species. Larvae of two isolates showed high-level resistance to levamisole (resistance ratios at the IC50 > 600) while the third isolate showed a degree of heterogeneity, with a resistance factor of only 1.1-fold at the IC50 alongside the presence of a resistant subpopulation. Transcription patterns for nAChR subunit genes showed a great degree of variability across the different life stages and isolates. The most consistent observation was the down-regulation of Hco-unc-63a in adults of all resistant isolates. Transcription of this gene was also reduced in the L3 stage of the two most resistant isolates, highlighting its potential as a resistance marker in the readily accessible free-living stages. There was down regulation of all four Hco-unc-29 paralogs in adults of one resistant isolate. There were no consistent changes in expression of P-gps or ancillary protein genes across the resistant isolates. The present study has demonstrated a complex pattern of nAChR subunit gene expression in H. contortus, and has highlighted several instances where reduced expression of subunit genes (Hco-unc-63a, Hco-unc-29) may be associated with the observed levamisole resistance. The data also suggests that it will be difficult to detect resistance using gene transcription-based methods on pooled larval samples from isolates containing only a resistant subpopulation due to

  5. Utilization of Ancillary Data Sets for Conceptual SMAP Mission Algorithm Development and Product Generation

    Science.gov (United States)

    O'Neill, P.; Podest, E.

    2011-01-01

    The planned Soil Moisture Active Passive (SMAP) mission is one of the first Earth observation satellites being developed by NASA in response to the National Research Council's Decadal Survey, Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond [1]. Scheduled to launch late in 2014, the proposed SMAP mission would provide high resolution and frequent revisit global mapping of soil moisture and freeze/thaw state, utilizing enhanced Radio Frequency Interference (RFI) mitigation approaches to collect new measurements of the hydrological condition of the Earth's surface. The SMAP instrument design incorporates an L-band radar (3 km) and an L band radiometer (40 km) sharing a single 6-meter rotating mesh antenna to provide measurements of soil moisture and landscape freeze/thaw state [2]. These observations would (1) improve our understanding of linkages between the Earth's water, energy, and carbon cycles, (2) benefit many application areas including numerical weather and climate prediction, flood and drought monitoring, agricultural productivity, human health, and national security, (3) help to address priority questions on climate change, and (4) potentially provide continuity with brightness temperature and soil moisture measurements from ESA's SMOS (Soil Moisture Ocean Salinity) and NASA's Aquarius missions. In the planned SMAP mission prelaunch time frame, baseline algorithms are being developed for generating (1) soil moisture products both from radiometer measurements on a 36 km grid and from combined radar/radiometer measurements on a 9 km grid, and (2) freeze/thaw products from radar measurements on a 3 km grid. These retrieval algorithms need a variety of global ancillary data, both static and dynamic, to run the retrieval models, constrain the retrievals, and provide flags for indicating retrieval quality. The choice of which ancillary dataset to use for a particular SMAP product would be based on a number of factors

  6. Cleft Lip Repair: The Hybrid Subunit Method.

    Science.gov (United States)

    Tollefson, Travis T

    2016-04-01

    The unilateral cleft lip repair is one of the most rewarding and challenging of plastic surgery procedures. Surgeons have introduced a variety of straight line, geometric, and rotation-advancement designs, while in practice the majority of North American surgeons have been using hybrids of the rotation-advancement techniques. The anatomic subunit approach was introduced in 2005 by Fisher and has gained popularity, with early adopters of the design touting its simplicity and effectiveness. The objectives of this article are to summarize the basic tenets of respecting the philtral subunit, accurate measurement and planning, and tips for transitioning to this subunit approach.

  7. Measuring Generator Performance in Providing Regulation and Load-Following Ancillary Services

    Energy Technology Data Exchange (ETDEWEB)

    Hirst, E.

    2001-04-05

    In an earlier project, we analyzed data on total system load as well as the loads of eight large industrial customers (Kirby and Hirst 2000). We analyzed these data in terms of system and customer-specific requirements for two real-power ancillary services, regulation and load following. We conducted these analyses using 12 days of data from February 1999 plus 12 days of data from August and September 1999. The project discussed here focused on the supply side (provision) of these two services. Specifically, we examined the output of this control area's generation resources, in aggregate and by unit. We analyzed the performance of these generating units in two ways. First, we analyzed the contribution of these generators to overall system performance [generally relative to the North American Electric Reliability Council (NERC) standards]. Second, we analyzed performance relative to what the control center requested of the generators.

  8. DR Resources for Energy and Ancillary Services in the West (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Hummon, M.; Kiliccote, S.

    2014-04-01

    Demand response (DR) resources present a potentially important source of grid flexibility however, DR in grid models is limited by data availability and modeling complexity. This presentation focuses on the co-optimization of DR resources to provide energy and ancillary services in a production cost model of the Colorado "test system". We assume each DR resource can provide energy services by either shedding load or shifting its use between different times, as well as operating reserves: frequency regulation, contingency reserve, and flexibility (or ramping) reserve. There are significant variations in the availabilities of different types of DR resources, which affect both the operational savings as well as the revenue for each DR resource. The results presented include the system-wide avoided fuel and generator start-up costs as well as the composite revenue for each DR resource by energy and operating reserves.

  9. Yoga as an ancillary treatment for neurological and psychiatric disorders: a review.

    Science.gov (United States)

    Meyer, Hilary B; Katsman, Alina; Sones, Alexander C; Auerbach, Daniel E; Ames, Donna; Rubin, Robert T

    2012-01-01

    Yoga is gaining acceptance as an ancillary medical treatment, but there have been few studies evaluating its therapeutic benefits in neurological and major psychiatric conditions. The authors reviewed the literature in English on the efficacy of yoga for these disorders. Only randomized, controlled trials were included, with the exception of the only study of yoga for bipolar disorder, which was observational. Trials were excluded if yoga was not the central component of the intervention. Of seven randomized, controlled trials of yoga in patients with neurological disorders, six found significant, positive effects. Of 13 randomized, controlled trials of yoga in patients with psychiatric disorders, 10 found significant, positive effects. These results, although encouraging, indicate that additional randomized, controlled studies are needed to critically define the benefits of yoga for both neurological and psychiatric disorders.

  10. DMSO molecule as ancillary ligand in Ru-based catalysts for ring opening metathesis polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Santana, Sirlane A.A.; Carvalho Junior, Valdemiro P.; Lima-Neto, Benedito S. [Universidade de Sao Paulo, Sao Carlos (USP), SP (Brazil). Inst. de Quimica

    2010-07-01

    The ring-opening metathesis polymerization (ROMP) of norbornene (NBE) occurs in the presence of the fac-[RuCl{sub 2}(S-DMSO){sub 3}(O-DMSO)] complex and ethyldiazoacetate (5 {mu}L), where DMSO is S- or O-bonded dimethylsulfoxide. The yield is 62% (PDI = 1.64) at room temperature for 5 min and 88% (PDI 1.93) at 50 deg C for 30 min, with [NBE]/[Ru] = 516 in CHCl{sub 3}. The yield is 90% (PDI = 1.64) in the presence of NBu{sub 4}ClO{sub 4} at room temperature for 5 min. The complex is practically inactive when one or two molecules of DMSO are replaced by pyridine, imidazole, 2-methyl-imidazole or benzimidazole. The in situ formation of the catalytic species and the behavior of the DMSO molecules as ancillary ligands in the reactivity of the RuII complexes are discussed. (author)

  11. Ancillary services and the integration of substantial quantities of wind power

    Energy Technology Data Exchange (ETDEWEB)

    OEstergaard, Poul Alberg [Department of Development and Planning, Aalborg University, Fibigerstraede 13, 9220 Aalborg OE (Denmark)

    2006-05-15

    Denmark has the World's highest penetration of grid connected wind power in electricity generation with a share of 15.0% of total domestic demand in 2002 [Danish Energy Authority. Rapport fra arbejdsgruppen om kraftvarme- og VE-elektricitet. Bilagsrapport. Copenhagen: Danish Energy Authority; 2001]. This is unevenly distributed in the two separate electricity systems comprising Denmark, giving a 2003 share as high as 21% in Western Denmark [Eltra. http://www.Eltra.dk. Skaerbaek: Eltra; 2004] compared with a more modest 8% in the more densely populated Eastern Denmark [Elkraft System. Miljoberetning 2004. Ballerup: Elkraft System; 2004]. At the same time, Denmark has other forms of distributed generation, e.g., extensive cogeneration of heat and power (CHP) plants for district heating or for covering industrial heat demands. This results in a high fuel-efficiency but also in a technically complex energy system. This combination of wind power and CHP is a challenge for system operators but also gives opportunities. This article analyses the possibilities for integrating even more wind power using new power balancing strategies that exploit the possibilities given by the existence of CHP plants as well as the potential impact of heat pumps used for district heating and installed for integration purposes. The analyses are made with particular focus on grid stability and delivery of ancillary services (required to control voltage and frequency) and demonstrate that it is possible to accommodate 50% or more wind power without having to rely on import or export for power balancing. Relying on import and export sets demands on the neighbouring countries which may not be met. Compulsion to export or import furthermore gives a poor bargaining position on the electricity market. However, in order to reach such high levels of wind power, the generating equipment must be able to supply ancillary services in contrast to their present abilities. (author)

  12. Gene targeting of CK2 catalytic subunits

    Science.gov (United States)

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

    2013-01-01

    Protein kinase CK2 is a highly conserved and ubiquitous serine–threonine kinase. It is a tetrameric enzyme that is made up of two regulatory CK2β subunits and two catalytic subunits, either CK2α/CK2α, CK2α/ CK2α′, or CK2α′/CK2α′. 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 CK2α′is essential for male germ cell development, and we now demonstrate that CK2α has an essential role in embryogenesis, as mice lacking CK2α die in mid-embryogenesis, with cardiac and neural tube defects. PMID:18594950

  13. 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.

  14. 76 FR 36400 - Third-Party Provision of Ancillary Services; Accounting and Financial Reporting for New Electric...

    Science.gov (United States)

    2011-06-22

    ... Energy Regulatory Commission 18 CFR Chapter I Third-Party Provision of Ancillary Services; Accounting and..., irrespective of the technologies used for such provision; and the adequacy of current accounting and reporting... provision; and (2) the adequacy of current accounting and reporting requirements as they pertain to...

  15. Scheme for Implementation of Ancillary-Free 1 → 3 Optimal Phase-Covariant Quantum Cloning with Trapped Ions

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yan-Ping; YANG Rong-Can; LI Ping; LI Hong-Cai; GOU Qing-Quan; LIN Xiu; LIU Wei-Na; HUANG Zhi-Ping; XIE Hong

    2008-01-01

    We propose a simple scheme for the implementation of the ancillary-free 1 → 3 optimal phase-covariant quantum cloning for x-y equatorial qubits in ion-trap system. In the scheme, the vibrational mode is only virtually excited, which is very important in view of decoherence. The present proposal can be realized based on current available technologies.

  16. Profile of Hashimoto's Thyroiditis in Sri Lankans: Is There an Increased Risk of Ancillary Pathologies in Hashimoto's Thyroiditis?

    OpenAIRE

    Eranga Himalee Siriweera; Neelakanthi Vajira Illangakoon Ratnatunga

    2010-01-01

    Hashimoto's thyroiditis has been reported to be associated with many neoplastic and nonneoplastic thyroid pathologies. This retrospective study aims to determine the demographic profile of Hashimoto's thyroiditis in Sri Lankans, document ancillary pathologies in Hashimoto's thyroiditis, and determine whether there is an increased risk of occurrence of malignancies, benign neoplasms, and nonneoplastic benign lesions in Hashimoto's thyroiditis by comparing with thyroids showing multinodular goi...

  17. Development of a solid polymer electrolyte electrolysis cell module and ancillary components for a breadboard water electrolysis system

    Science.gov (United States)

    Porter, F. J., Jr.

    1972-01-01

    Solid polymer electrolyte technology in a water electrolysis system along with ancillary components to generate oxygen and hydrogen for a manned space station application are considered. Standard commercial components are utilized wherever possible. Presented are the results of investigations, surveys, tests, conclusions and recommendations for future development efforts.

  18. Planck intermediate results XXIII. Galactic plane emission components derived from Planck with ancillary data

    DEFF Research Database (Denmark)

    Ade, P. A. R.; Aghanim, N.; Arnaud, M.;

    2015-01-01

    Planck data when combined with ancillary data provide a unique opportunity to separate the diuse emission components of the inner Galaxy.The purpose of the paper is to elucidate the morphology of the various emission components in the strong star-formation region lying inside thesolar radius and ...

  19. Utilization of ancillary studies in the cytologic diagnosis of biliary and pancreatic lesions: The Papanicolaou Society of Cytopathology Guidelines

    Directory of Open Access Journals (Sweden)

    Lester J. Layfield

    2014-01-01

    Full Text Available The Papanicolaou Society of Cytopathology has developed a set of guidelines for pancreatobiliary cytology including indications for endoscopic ultrasound guided fine needle aspiration, terminology and nomenclature of pancreatobiliary disease, ancillary testing and post-biopsy management. All documents are based on the expertise of the authors, a review of the literature, discussion of the draft document at several national and international meetings and synthesis of selected online comments of the draft document. This document presents the results of these discussions regarding the use of ancillary testing in the cytologic diagnosis of biliary and pancreatic lesions. Currently, fluorescence in-situ hybridization (FISH appears to be the most clinically relevant ancillary technique for cytology of bile duct strictures. The addition of FISH analysis to routine cytologic evaluation appears to yield the highest sensitivity without loss in specificity. Loss of immunohistochemical staining for the protein product of the SMAD4 gene and positive staining for mesothelin support a diagnosis of ductal adenocarcinoma. Immunohistochemical markers for endocrine and exocrine differentiation are sufficient for a diagnosis of endocrine and acinar tumors. Nuclear staining for beta-catenin supports a diagnosis of solid-pseudopapillary neoplasm. Cyst fluid analysis for amylase and carcinoembryonic antigen aids in the pre-operative classification of pancreatic cysts. A number of gene mutations (KRAS, GNAS, von Hippel-Lindau, RNF43 and CTNNB1 may be of aid in the diagnosis of cystic neoplasms. Other ancillary techniques do not appear to improve diagnostic sensitivity sufficiently to justify their increased costs.

  20. 75 FR 63167 - San Diego Gas and Electric Company v. Sellers of Energy and Ancillary Services Into Markets...

    Science.gov (United States)

    2010-10-14

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission San Diego Gas and Electric Company v. Sellers of Energy and Ancillary Services Into Markets Operated by the California Independent System Operator Corporation and the...

  1. 75 FR 22125 - Market-Based Rates for Wholesale Sales of Electric Energy, Capacity and Ancillary Services by...

    Science.gov (United States)

    2010-04-27

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Market-Based Rates for Wholesale Sales of Electric Energy, Capacity and... Electric Energy, Capacity and Ancillary Services by Public Utilities, Order No. 697- C, FERC Stats. &...

  2. 75 FR 14342 - Market-Based Rates for Wholesale Sales of Electric Energy, Capacity and Ancillary Services by...

    Science.gov (United States)

    2010-03-25

    ... Energy Regulatory Commission 18 CFR Part 35 Market-Based Rates for Wholesale Sales of Electric Energy... Electric Energy, Capacity and Ancillary Services by Public Utilities, Order No. 697- C, FERC Stats. & Regs. ] 31,291 (2009). \\2\\ 18 CFR 35.42. \\3\\ Market-Based Rates for Wholesale Sales of Electric...

  3. Evaluation of freely available ancillary data used for detailed soil mapping in Brazil

    Science.gov (United States)

    Samuel-Rosa, Alessandro; Anjos, Lúcia; Vasques, Gustavo; Heuvelink, Gerard

    2014-05-01

    Brazil is one of the world's largest food producers, and is home of both largest rainforest and largest supply of renewable fresh water on Earth. However, it lacks detailed soil information in extensive areas of the country. The best soil map covering the entire country was published at a scale of 1:5,000,000. Termination of governmental support for systematic soil mapping in the 1980's made detailed soil mapping of the whole country a very difficult task to accomplish. Nowadays, due to new user-driven demands (e.g. precision agriculture), most detailed soil maps are produced for small size areas. Many of them rely on as is freely available ancillary data, although their accuracy is usually not reported or unknown. Results from a validation exercise that we performed using ground control points from a small hilly catchment (20 km²) in Southern Brazil (-53.7995ºE, -29.6355ºN) indicate that most freely available ancillary data needs some type of correction before use. Georeferenced and orthorectified RapidEye imagery (recently acquired by the Brazilian government) has a horizontal accuracy (root-mean-square error, RMSE) of 37 m, which is worse than the value published in the metadata (32 m). Like any remote sensing imagery, RapidEye imagery needs to be correctly registered before its use for soil mapping. Topographic maps produced by the Brazilian Army and derived geological maps (scale of 1:25,000) have a horizontal accuracy of 65 m, which is more than four times the maximum value allowed by Brazilian legislation (15 m). Worse results were found for geological maps derived from 1:50,000 topographic maps (RMSE = 147 m), for which the maximum allowed value is 30 m. In most cases positional errors are of systematic origin and can be easily corrected (e.g., affine transformation). ASTER GDEM has many holes and is very noisy, making it of little use in the studied area. TOPODATA, which is SRTM kriged from originally 3 to 1 arc-second by the Brazilian National

  4. Preliminary Results of Ancillary Safety Analyses Supporting TREAT LEU Conversion Activities

    Energy Technology Data Exchange (ETDEWEB)

    Brunett, A. J. [Argonne National Lab. (ANL), Argonne, IL (United States); Fei, T. [Argonne National Lab. (ANL), Argonne, IL (United States); Strons, P. S. [Argonne National Lab. (ANL), Argonne, IL (United States); Papadias, D. D. [Argonne National Lab. (ANL), Argonne, IL (United States); Hoffman, E. A. [Argonne National Lab. (ANL), Argonne, IL (United States); Kontogeorgakos, D. C. [Argonne National Lab. (ANL), Argonne, IL (United States); Connaway, H. M. [Argonne National Lab. (ANL), Argonne, IL (United States); Wright, A. E. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-10-01

    The Transient Reactor Test Facility (TREAT), located at Idaho National Laboratory (INL), is a test facility designed to evaluate the performance of reactor fuels and materials under transient accident conditions. The facility, an air-cooled, graphite-moderated reactor designed to utilize fuel containing high-enriched uranium (HEU), has been in non-operational standby status since 1994. Currently, in support of the missions of the Department of Energy (DOE) National Nuclear Security Administration (NNSA) Material Management and Minimization (M3) Reactor Conversion Program, a new core design is being developed for TREAT that will utilize low-enriched uranium (LEU). The primary objective of this conversion effort is to design an LEU core that is capable of meeting the performance characteristics of the existing HEU core. Minimal, if any, changes are anticipated for the supporting systems (e.g. reactor trip system, filtration/cooling system, etc.); therefore, the LEU core must also be able to function with the existing supporting systems, and must also satisfy acceptable safety limits. In support of the LEU conversion effort, a range of ancillary safety analyses are required to evaluate the LEU core operation relative to that of the existing facility. These analyses cover neutronics, shielding, and thermal hydraulic topics that have been identified as having the potential to have reduced safety margins due to conversion to LEU fuel, or are required to support the required safety analyses documentation. The majority of these ancillary tasks have been identified in [1] and [2]. The purpose of this report is to document the ancillary safety analyses that have been performed at Argonne National Laboratory during the early stages of the LEU design effort, and to describe ongoing and anticipated analyses. For all analyses presented in this report, methodologies are utilized that are consistent with, or improved from, those used in analyses for the HEU Final Safety Analysis

  5. GABA B receptor subunit expression in glia.

    Science.gov (United States)

    Charles, K J; Deuchars, J; Davies, C H; Pangalos, M N

    2003-09-01

    GABA(B) receptor subunits are widely expressed on neurons throughout the CNS, at both pre- and postsynaptic sites, where they mediate the late, slow component of the inhibitory response to the major inhibitory neurotransmitter GABA. The existence of functional GABA(B) receptors on nonneuronal cells has been reported previously, although the molecular composition of these receptors has not yet been described. Here we demonstrate for the first time, using immunohistochemistry the expression of GABA(B1a), GABA(B1b), and GABA(B2) on nonneuronal cells of the rat CNS. All three principle GABA(B) receptor subunits were expressed on these cells irrespective of whether they had been cultured or found within brain tissue sections. At the ultrastructural level GABA(B) receptor subunits were expressed on astrocytic processes surrounding both symmetrical and assymetrical synapses in the CA1 subregion of the hippocampus. In addition, GABA(B1a), GABA(B1b), and GABA(B2) receptor subunits were expressed on activated microglia in culture but were not found on myelin forming oligodendrocytes in the white matter of rat spinal cord. Together these data demonstrate that the obligate subunits of functional GABA(B) receptors are expressed in astrocytes and microglia in the rat CNS.

  6. Using ancillary information to improve hypocenter estimation: Bayesian single event location (BSEL)

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Dale N [Los Alamos National Laboratory

    2008-01-01

    We have developed and tested an algorithm, Bayesian Single Event Location (BSEL), for estimating the location of a seismic event. The main driver for our research is the inadequate representation of ancillary information in the hypocenter estimation procedure. The added benefit is that we have also addressed instability issues often encountered with historical NLR solvers (e.g., non-convergence or seismically infeasible results). BSEL differs from established nonlinear regression techniques by using a Bayesian prior probability density function (prior PDF) to incorporate ancillary physical basis constraints about event location. P-wave arrival times from seismic events are used in the development. Depth, a focus of this paper, may be modeled with a prior PDF (potentially skewed) that captures physical basis bounds from surface wave observations. This PDF is constructed from a Rayleigh wave depth excitation eigenfunction that is based on the observed minimum period from a spectrogram analysis and estimated near-source elastic parameters. For example, if the surface wave is an Rg phase, it potentially provides a strong constraint for depth, which has important implications for remote monitoring of nuclear explosions. The proposed Bayesian algorithm is illustrated with events that demonstrate its congruity with established hypocenter estimation methods and its application potential. The BSEL method is applied to three events: (1) A shallow Mw 4 earthquake that occurred near Bardwell, KY on June 6, 2003, (2) the Mw 5.6 earthquake of July 26, 2005 that occurred near Dillon, MT, and (3) a deep Mw 5.7 earthquake that occurred off the coast of Japan on April 22, 1980. A strong Rg was observed from the Bardwell, KY earthquake that places very strong constraints on depth and origin time. No Rg was observed for the Dillon, MT earthquake, but we used the minimum observed period of a Rayleigh wave (7 seconds) to reduce the depth and origin time uncertainty. Because the Japan

  7. Impact of Production from Photovoltaic Power Plants on Increase of Ancillary Services in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Martin Smocek

    2016-01-01

    Full Text Available Renewable energy resources represent a noticeable part of the overall energetic concept development. New integration of renewable energy resources into power grids has a significant impact on the reliability and quality of power supply. The major problem of the photovoltaic and wind power plants is their dependency on weather conditions, since it has a direct effect on their immediate output produced that shows stochastic behaviour. These stochastic outputs result in very adverse impacts on the power grid. Further development of these resources could lead to exceeding of the control and absorption abilities of the power grid. The power grid must be set in balance with respect to the production and consumption of electric power at any time. The operation of photovoltaic power plants impair keeping this balance. That has an adverse impact on the very operation and maintenance of network parameters within the extent required. This survey deals with analysis focused on operation of the photovoltaic power plants with respect to the increase of reserve power in ancillary services in the Czech Republic.

  8. Incorporating residential AC load control into ancillary service markets: Measurement and settlement

    Energy Technology Data Exchange (ETDEWEB)

    Bode, Josh L.; Sullivan, Michael J.; Berghman, Dries; Eto, Joseph H.

    2013-05-01

    Many pre-existing air conditioner load control programs can provide valuable operational flexibility but have not been incorporated into electricity ancillary service markets or grid operations. Multiple demonstrations have shown that residential air conditioner (AC) response can deliver resources quickly and can provide contingency reserves. A key policy hurdle to be overcome before AC load control can be fully incorporated into markets is how to balance the accuracy, cost, and complexity of methods available for the settlement of load curtailment. Overcoming this hurdle requires a means for assessing the accuracy of shorter-term AC load control demand reduction estimation approaches in an unbiased manner. This paper applies such a method to compare the accuracy of approaches varying in cost and complexity ? including regression analysis, load matching and control group approaches ? using feeder data, household data and AC end-use data. We recommend a practical approach for settlement, relying on an annually updated set of tables, with pre-calculated reduction estimates. These tables allow users to look up the demand reduction per device based on daily maximum temperature, geographic region and hour of day, simplifying settlement and providing a solution to the policy problem presented in this paper.

  9. Proposal for a change of contractor to operate the hostels, apartments and ancillary premises

    CERN Document Server

    2001-01-01

    The purpose of this document is to inform the Finance Committee of the final outcome of the negotiations with the firm to which the contract was adjudicated for the operation of the hostels, apartments and ancillary premises run by the CERN Housing Service and to request approval for the contract placed with the second lowest bidder. In September 2000, the Finance Committee agreed to the negotiation of a contract with VIENNA INTERNATIONAL HOTEL MANAGEMENT (AT) - SEREG (CH) (cf. CERN/FC/4311). For the reasons explained in this document, the Finance Committee is now invited to approve a contract with the consortium ISS MULTISERVICE (CH) - ISS GEBAEUDESERVICE (DE), the second lowest bidder, for an initial period of five years, from 1 January 2001, for a total amount of 7 206 000 Swiss francs, not subject to revision until 31 December 2001. The contract includes an option for two one-year extensions beyond the initial five-year period. The consortium has indicated the following distribution by country of the cont...

  10. Assessing the economic potential of electric vehicles to provide ancillary services. The case of Germany

    Energy Technology Data Exchange (ETDEWEB)

    Schuller, Alexander; Rieger, Fabian [Karlsruhe Institute of Technology, Karlsruhe (Germany)

    2013-09-15

    The Vehicle-to-Grid (V2G) concept is a promising possibility for the integration of electric vehicles (EVs) into the power grid. This article presents an economic evaluation of EVs participating in the ancillary service market (primary, secondary and tertiary regulation) for the case of Germany, based on a price data set from 2011 and 2012. We examine the economic potential of nine general options to participate in the regulation market based on real-life EV specifications, connection powers and regulation energy prices. Results show that in the most profitable case a maximum average yearly profit of 730.31 Euro per vehicle is possible for negative regulation with payment direction TSO to provider in the secondary regulation market. Furthermore a sensitivity analysis is performed for all of the analyzed participation scenarios in order to identify crucial parameters for a possible V2G implementation. Major parameters for the successful implementation of V2G are the provided power per vehicle, the time an EV is available to the grid and the variable energy storage costs it incurs.

  11. Workshop on environmental assessment. [Regulation of applications of nuclear energy and related ancillary systems

    Energy Technology Data Exchange (ETDEWEB)

    Watson, E.C. (comp.)

    1982-07-01

    Objectives of the workshop were: to review and evaluate the state-of-the-art of environmental impact assessments as applied to the regulation of applications of nuclear energy and related ancillary systems; to identify areas where existing technology allows establishing acceptable methods or standard practices that will meet the requirements of the NRC regulations, standards and guides for both normal operations and off-standard conditions including accident considerations; to illuminate topics where existing models or analytical methods are deficient because of unverified assumptions, a paucity of empirical data, conflicting results reported in the literature or a need for observation of operation systems; to compile, analyze and synthesize a prioritized set of research needs to advance the state-of-the-art to the level which will meet all of the requirements of the Commission's regulations, standards and guides; and to develop bases for maintaining the core of regulatory guidance at the optimum level balancing technical capabilities with practical considerations of cost and value to the regulatory process. The discussion held in small group sessions on aquatic, atmospheric, and terrestrial pathways are presented. The following research needs were identified as common to all three groups: validation of models; characterization of source terms; development of screening techniques; basis for de minimis levels of contamination; and updating of objectives for environmental monitoring programs.

  12. Analysis of the Effects of a Flexible Ramping Ancillary Service Product on Power System Operations: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Krad, Ibrahim; Ibanez, Eduardo; Ela, Erik

    2015-10-19

    The recent increased interest in utilizing variable generation (VG) resources such as wind and solar in power systems has motivated investigations into new operating procedures. Although these resources provide desirable value to a system (e.g., no fuel costs or emissions), interconnecting them provides unique challenges. Their variable, non-controllable nature in particular requires significant attention, because it directly results in increased power system variability and uncertainty. One way to handle this is via new operating reserve schemes. Operating reserves provide upward and downward generation and ramping capacity to counteract uncertainty and variability prior to their realization. For instance, uncertainty and variability in real-time dispatch can be accounted for in the hour-ahead unit commitment. New operating reserve methodologies that specifically account for the increased variability and uncertainty caused by VG are currently being investigated and developed by academia and industry. This paper examines one method inspired by the new operating reserve product being proposed by the California Independent System Operator. The method is based on examining the potential ramping requirements at any given time and enforcing those requirements via a reserve demand curve in the market-clearing optimization as an additional ancillary service product.

  13. Catalytic water oxidation by mononuclear Ru complexes with an anionic ancillary ligand.

    Science.gov (United States)

    Tong, Lianpeng; Inge, A Ken; Duan, Lele; Wang, Lei; Zou, Xiaodong; Sun, Licheng

    2013-03-04

    Mononuclear Ru-based water oxidation catalysts containing anionic ancillary ligands have shown promising catalytic efficiency and intriguing properties. However, their insolubility in water restricts a detailed mechanism investigation. In order to overcome this disadvantage, complexes [Ru(II)(bpc)(bpy)OH2](+) (1(+), bpc = 2,2'-bipyridine-6-carboxylate, bpy = 2,2'-bipyridine) and [Ru(II)(bpc)(pic)3](+) (2(+), pic = 4-picoline) were prepared and fully characterized, which features an anionic tridentate ligand and has enough solubility for spectroscopic study in water. Using Ce(IV) as an electron acceptor, both complexes are able to catalyze O2-evolving reaction with an impressive rate constant. On the basis of the electrochemical and kinetic studies, a water nucleophilic attack pathway was proposed as the dominant catalytic cycle of the catalytic water oxidation by 1(+), within which several intermediates were detected by MS. Meanwhile, an auxiliary pathway that is related to the concentration of Ce(IV) was also revealed. The effect of anionic ligand regarding catalytic water oxidation was discussed explicitly in comparison with previously reported mononuclear Ru catalysts carrying neutral tridentate ligands, for example, 2,2':6',2″-terpyridine (tpy). When 2(+) was oxidized to the trivalent state, one of its picoline ligands dissociated from the Ru center. The rate constant of picoline dissociation was evaluated from time-resolved UV-vis spectra.

  14. Planck intermediate results. XXIII. Galactic plane emission components derived from Planck with ancillary data

    CERN Document Server

    Ade, P A R; Alves, M I R; Arnaud, M; Ashdown, M; Atrio-Barandela, F; Aumont, J; Baccigalupi, C; Banday, A J; Barreiro, R B; Battaner, E; Benabed, K; Benoit-Lévy, A; Bernard, J -P; Bersanelli, M; Bielewicz, P; Bobin, J; Bonaldi, A; Bond, J R; Bouchet, F R; Boulanger, F; Burigana, C; Cardoso, J -F; Catalano, A; Chamballu, A; Chiang, H C; Christensen, P R; Clements, D L; Colombi, S; Colombo, L P L; Combet, C; Couchot, F; Crill, B P; Cuttaia, F; Danese, L; Davies, R D; Davis, R J; de Bernardis, P; de Rosa, A; de Zotti, G; Delabrouille, J; Dickinson, C; Diego, J M; Donzelli, S; Doré, O; Douspis, M; Dupac, X; Efstathiou, G; Enßlin, T A; Eriksen, H K; Finelli, F; Forni, O; Frailis, M; Franceschi, E; Galeotta, S; Ganga, K; Génova-Santos, R T; Ghosh, T; Giard, M; Giardino, G; Giraud-Héraud, Y; González-Nuevo, J; Górski, K M; Gregorio, A; Gruppuso, A; Hansen, F K; Harrison, D L; Henrot-Versillé, S; Herranz, D; Hildebrandt, S R; Hivon, E; Hobson, M; Hornstrup, A; Hovest, W; Huffenberger, K M; Jaffe, A H; Jaffe, T R; Jones, W C; Keihänen, E; Keskitalo, R; Kisner, T S; Kneissl, R; Knoche, J; Kunz, M; Kurki-Suonio, H; Lagache, G; Lähteenmäki, A; Lamarre, J -M; Lasenby, A; Lawrence, C R; Leonardi, R; Liguori, M; Lilje, P B; Linden-Vørnle, M; López-Caniego, M; Lubin, P M; Macías-Pérez, J F; Maino, D; Mandolesi, N; Martin, P G; Martínez-González, E; Masi, S; Massardi, M; Matarrese, S; Mazzotta, P; Meinhold, P R; Melchiorri, A; Mendes, L; Mennella, A; Migliaccio, M; Mitra, S; Miville-Deschênes, M -A; Moneti, A; Montier, L; Morgante, G; Mortlock, D; Munshi, D; Murphy, J A; Naselsky, P; Nati, F; Natoli, P; Nørgaard-Nielsen, H U; Noviello, F; Novikov, D; Novikov, I; Oxborrow, C A; Pagano, L; Pajot, F; Paladini, R; Paoletti, D; Pasian, F; Pearson, T J; Peel, M; Perdereau, O; Perrotta, F; Piacentini, F; Piat, M; Pierpaoli, E; Pietrobon, D; Plaszczynski, S; Pointecouteau, E; Polenta, G; Ponthieu, N; Popa, L; Pratt, G W; Prunet, S; Puget, J -L; Rachen, J P; Reach, W T; Rebolo, R; Reich, W; Reinecke, M; Remazeilles, M; Renault, C; Ricciardi, S; Riller, T; Ristorcelli, I; Rocha, G; Rosset, C; Roudier, G; Rubiño-Martín, J A; Rusholme, B; Sandri, M; Savini, G; Scott, D; Spencer, L D; Stolyarov, V; Strong, A W; Sutton, D; Suur-Uski, A -S; Sygnet, J -F; Tauber, J A; Tavagnacco, D; Terenzi, L; Tibbs, C T; Toffolatti, L; Tomasi, M; Tristram, M; Tucci, M; Valenziano, L; Valiviita, J; Van Tent, B; Varis, J; Vielva, P; Villa, F; Wade, L A; Wandelt, B D; Watson, R; Yvon, D; Zacchei, A; Zonca, A

    2014-01-01

    Planck data when combined with ancillary data provide a unique opportunity to separate the diffuse emission components of the inner Galaxy. The purpose of the paper is to elucidate the morphology of the various emission components in the strong star-formation region lying inside the solar radius and to clarify the relationship between the various components. The region of the Galactic plane covered is l=300-0-60deg where star-formation is highest and the emission is strong enough to make meaningful component separation. The latitude widths in this longitude range lie between 1deg and 2deg, which correspond to FWHM z-widths of 100-200pc at a typical distance of 6kpc. The four emission components studied here are synchrotron, free-free, anomalous microwave emission (AME), and thermal (vibrational) dust emission. These components are identified by constructing spectral energy distributions (SEDs) at positions along the Galactic plane using the wide frequency coverage of Planck (28.4-857GHz) in combination with l...

  15. Electric industry restructuring, ancillary services, and the potential impact on wind

    Energy Technology Data Exchange (ETDEWEB)

    Kirby, B.; Hirst, E. [Oak Ridge National Lab., TN (United States); Parsons, B.; Porter, K. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1997-12-31

    The new competitive electric power environment raises increased challenges for wind power. The DOE and EPRI wind programs have dealt extensively with the traditional vertically integrated utility planning and operating environment in which the host utility owns the generation (or purchases the power) and provides dispatch and transmission services. Under this traditional environment, 1794 MW of wind power, principally in California, have been successfully integrated into the U.S. electric power system. Another 4200 MW are installed elsewhere in the world. As issues have arisen, such as intermittency and voltage regulation, they have been successfully addressed with accepted power system procedures and practices. For an intermittent, non-dispatchable resource such as wind, new regulatory rules affecting power transmission services, raise questions about which ancillary services wind plants will be able to sell, which they will be required to purchase, and what the economic impacts will be on individual wind projects. This paper begins to look at issues of concern to wind in a restructured electric industry. The paper first briefly looks at the range of unbundled services and comments on their unique significance to wind. To illustrate the concerns that arise with restructuring, the paper then takes a more detailed look at a single service: regulation. Finally, the paper takes a brief look at technologies and strategies that could improve the competitive position of wind.

  16. Unmet Needs for Ancillary Services Among Hispanics/Latinos Receiving HIV Medical Care - United States, 2013-2014.

    Science.gov (United States)

    Korhonen, Lauren C; DeGroote, Nicholas P; Shouse, R Luke; Valleroy, Linda A; Prejean, Joseph; Bradley, Heather

    2016-10-14

    The prevalence of diagnosed human immunodeficiency virus (HIV) infection in Hispanics/Latinos in the United States is more than twice as high as the prevalence among non-Hispanic whites (1). Services that support retention in HIV medical care and assist with day-to-day living, referred to here as ancillary services, help persons living with HIV access HIV medical care, adhere to HIV treatment, and attain HIV viral suppression. The needs for these ancillary services among Hispanics/Latinos are not well described (2). To obtain nationally representative estimates of and reasons for unmet needs for such services among Hispanic/Latino adults receiving outpatient HIV medical care during 2013-2014, CDC analyzed data from the Medical Monitoring Project (MMP). The analysis found that Hispanics/Latinos in all age and sexual orientation/behavior subgroups reported substantial unmet needs, including 24% needing dental care, 21% needing eye or vision care, 15% needing food and nutrition services, and 9% needing transportation assistance. Addressing unmet needs for ancillary services among Hispanics/Latinos living with HIV might help increase access to HIV care, improve health outcomes, and reduce health disparities.

  17. Map of risks for the implementation of radio-frequency identification: application of ancillaries in the University Hospital Jean Verdier.

    Science.gov (United States)

    Bertrand, E; Schlatter, J

    2010-01-01

    Ancillaries are surgical instruments, such as orthopedical instruments set for reconstruction of knee (a mounting arm...) used to implant or extract prosthesis. Their management involves the departments of sterilization and surgery as well as the suppliers. Such a long circuit exposes the instruments to potential risk hazards like a lack of traceability as the suspicion of Creutzfeldt-Jakob. In order to reduce the risk of errors we will propose the implementation of radio-frequency identification (RFID) to trace the ancillaries during each step of the supply chain. The objective of our study is to analyze and to map the risks associated with RFID implementation. A preliminary analysis of risks (APR) is conducted to map out the hazards for the implementation of RFID. The APR identifies 162 scenarios with a maximum risk connected to environment and technology. To reduce the risks identified, 22 courses of action are proposed, such as audits, training, and internal controls. For each action, a procedure has been designed and evaluated. This preliminary analysis of risks allows targeting the potential dangers for the RFID implementation applied to ancillaries and reduces them significantly.

  18. Regional land cover characterization using Landsat thematic mapper data and ancillary data sources

    Science.gov (United States)

    Vogelmann, J.E.; Sohl, T.L.; Campbell, P.V.; Shaw, D.M.; ,

    1998-01-01

    As part of the activities of the Multi-Resolution Land Characteristics (MRLC) Interagency Consortium, an intermediate-scale land cover data set is being generated for the conterminous United States. This effort is being conducted on a region-by-region basis using U.S. Standard Federal Regions. To date, land cover data sets have been generated for Federal Regions 3 (Pennsylvania, West Virginia, Virginia, Maryland, and Delaware) and 2 (New York and New Jersey). Classification work is currently under way in Federal Region 4 (the southeastern United States), and land cover mapping activities have been started in Federal Regions 5 (the Great Lakes region) and 1 (New England). it is anticipated that a land cover data set for the conterminous United States will be completed by the end of 1999. A standard land cover classification legend is used, which is analogous to and compatible with other classification schemes. The primary MRLC regional classification scheme contains 23 land cover classes. The primary source of data for the project is the Landsat thematic mapper (TM) sensor. For each region, TM scenes representing both leaf-on and leaf-off conditions are acquired, preprocessed, and georeferenced to MRLC specifications. Mosaicked data are clustered using unsupervised classification, and individual clusters are labeled using aerial photographs. Individual clusters that represent more than one land cover unit are split using spatial modeling with multiple ancillary spatial data layers (most notably, digital elevation model, population, land use and land cover, and wetlands information). This approach yields regional land cover information suitable for a wide array of applications, including landscape metric analyses, land management, land cover change studies, and nutrient and pesticide runoff modeling.

  19. Cardiovascular Fat, Menopause, and Sex Hormones in Women: The SWAN Cardiovascular Fat Ancillary Study

    Science.gov (United States)

    Shields, Kelly J.; Janssen, Imke; Hanley, Carrie; Budoff, Matthew J.; Barinas-Mitchell, Emma; Everson-Rose, Susan A.; Powell, Lynda H.; Matthews, Karen A.

    2015-01-01

    Context: Cardiovascular risk increases in women after menopause. Mounting evidence demonstrates a role of cardiovascular fat (CF) in the pathogenesis of coronary heart disease, but no research has examined CF in relation to sex hormones or menopausal status in women. Objective: The objective was to determine the relationship between CF depots, menopausal status, and endogenous sex hormones. Design: Cross-sectional and longitudinal study designs were used. Setting: The setting included the Study of Women's Health Across the Nation (SWAN) Heart and Cardiovascular Fat Ancillary Study. Participants: A total of 456 women (mean age, 50.75 y); 62% premenopausal/early perimenopausal, and 38% late peri-/postmenopausal. Intervention: Menopausal status, endogenous sex hormones measured simultaneously with CF volumes, and circulating estradiol available 4.80 years (median) before CF measures. Main Outcome Measures: Volumes of CF (epicardial adipose tissue [EAT], paracardial adipose tissue [PAT], total heart adipose tissue [TAT = EAT + PAT], and aortic perivascular adipose tissue [PVAT]). Results: In final models, late peri-/postmenopausal women had 9.88% more EAT, 20.72% more PAT, and 11.69% more TAT volumes than pre-/early perimenopausal women (P < .05). PVAT was not associated with menopausal status. In final models, lower estradiol concentrations were associated with greater volumes of PAT and TAT (P < .05). Women with the greatest reduction in estradiol since baseline had greater volumes of PAT compared to women with the least reduction (P = .02). Conclusions: Late peri-/postmenopausal women have greater volumes of heart fat compared with pre-/early perimenopausal women independent of age, obesity, and other covariates. Endogenous sex hormones are associated with CF. Perhaps CF plays a role in the higher risk of coronary heart disease reported in women after menopause. PMID:26176800

  20. Camera traps and mark-resight models: The value of ancillary data for evaluating assumptions

    Science.gov (United States)

    Parsons, Arielle W.; Simons, Theodore R.; Pollock, Kenneth H.; Stoskopf, Michael K.; Stocking, Jessica J.; O'Connell, Allan F.

    2015-01-01

    Unbiased estimators of abundance and density are fundamental to the study of animal ecology and critical for making sound management decisions. Capture–recapture models are generally considered the most robust approach for estimating these parameters but rely on a number of assumptions that are often violated but rarely validated. Mark-resight models, a form of capture–recapture, are well suited for use with noninvasive sampling methods and allow for a number of assumptions to be relaxed. We used ancillary data from continuous video and radio telemetry to evaluate the assumptions of mark-resight models for abundance estimation on a barrier island raccoon (Procyon lotor) population using camera traps. Our island study site was geographically closed, allowing us to estimate real survival and in situ recruitment in addition to population size. We found several sources of bias due to heterogeneity of capture probabilities in our study, including camera placement, animal movement, island physiography, and animal behavior. Almost all sources of heterogeneity could be accounted for using the sophisticated mark-resight models developed by McClintock et al. (2009b) and this model generated estimates similar to a spatially explicit mark-resight model previously developed for this population during our study. Spatially explicit capture–recapture models have become an important tool in ecology and confer a number of advantages; however, non-spatial models that account for inherent individual heterogeneity may perform nearly as well, especially where immigration and emigration are limited. Non-spatial models are computationally less demanding, do not make implicit assumptions related to the isotropy of home ranges, and can provide insights with respect to the biological traits of the local population.

  1. Probing subunit-subunit interactions in the yeast vacuolar ATPase by peptide arrays.

    Directory of Open Access Journals (Sweden)

    Lee S Parsons

    Full Text Available BACKGROUND: Vacuolar (H(+-ATPase (V-ATPase; V(1V(o-ATPase is a large multisubunit enzyme complex found in the endomembrane system of all eukaryotic cells where its proton pumping action serves to acidify subcellular organelles. In the plasma membrane of certain specialized tissues, V-ATPase functions to pump protons from the cytoplasm into the extracellular space. The activity of the V-ATPase is regulated by a reversible dissociation mechanism that involves breaking and re-forming of protein-protein interactions in the V(1-ATPase - V(o-proton channel interface. The mechanism responsible for regulated V-ATPase dissociation is poorly understood, largely due to a lack of detailed knowledge of the molecular interactions that are responsible for the structural and functional link between the soluble ATPase and membrane bound proton channel domains. METHODOLOGY/PRINCIPAL FINDINGS: To gain insight into where some of the stator subunits of the V-ATPase associate with each other, we have developed peptide arrays from the primary sequences of V-ATPase subunits. By probing the peptide arrays with individually expressed V-ATPase subunits, we have identified several key interactions involving stator subunits E, G, C, H and the N-terminal domain of the membrane bound a subunit. CONCLUSIONS: The subunit-peptide interactions identified from the peptide arrays complement low resolution structural models of the eukaryotic vacuolar ATPase obtained from transmission electron microscopy. The subunit-subunit interaction data are discussed in context of our current model of reversible enzyme dissociation.

  2. Subunit organization in cytoplasmic dynein subcomplexes

    Science.gov (United States)

    King, Stephen J.; Bonilla, Myriam; Rodgers, Michael E.; Schroer, Trina A.

    2002-01-01

    Because cytoplasmic dynein plays numerous critical roles in eukaryotic cells, determining the subunit composition and the organization and functions of the subunits within dynein are important goals. This has been difficult partly because of accessory polypeptide heterogeneity of dynein populations. The motor domain containing heavy chains of cytoplasmic dynein are associated with multiple intermediate, light intermediate, and light chain accessory polypeptides. We examined the organization of these subunits within cytoplasmic dynein by separating the molecule into two distinct subcomplexes. These subcomplexes were competent to reassemble into a molecule with dynein-like properties. One subcomplex was composed of the dynein heavy and light intermediate chains whereas the other subcomplex was composed of the intermediate and light chains. The intermediate and light chain subcomplex could be further separated into two pools, only one of which contained dynein light chains. The two pools had distinct intermediate chain compositions, suggesting that intermediate chain isoforms have different light chain–binding properties. When the two intermediate chain pools were characterized by analytical velocity sedimentation, at least four molecular components were seen: intermediate chain monomers, intermediate chain dimers, intermediate chain monomers with bound light chains, and a mixture of intermediate chain dimers with assorted bound light chains. These data provide new insights into the compositional heterogeneity and assembly of the cytoplasmic dynein complex and suggest that individual dynein molecules have distinct molecular compositions in vivo. PMID:11967380

  3. Impact of Market Behavior, Fleet Composition, and Ancillary Services on Revenue Sufficiency

    Energy Technology Data Exchange (ETDEWEB)

    Frew, Bethany [National Renewable Energy Lab. (NREL), Golden, CO (United States); Gallo, Giulia [National Renewable Energy Lab. (NREL), Golden, CO (United States); Brinkman, Gregory [National Renewable Energy Lab. (NREL), Golden, CO (United States); Milligan, Michael [National Renewable Energy Lab. (NREL), Golden, CO (United States); Clark, Kara [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bloom, Aaron [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-06-01

    Revenue insufficiency, or the missing money problem, occurs when the revenues that generators earn from the market are not sufficient to cover both fixed and variable costs to remain in the market and/or justify investments in new capacity, which may be needed for reliability. The near-zero marginal cost of variable renewable generators further exacerbates these revenue challenges. Estimating the extent of the missing money problem in current electricity markets is an important, nontrivial task that requires representing both how the power system operates and how market participants behave. This paper explores the missing money problem using a production cost model that represented a simplified version of the Electric Reliability Council of Texas (ERCOT) energy-only market for the years 2012-2014. We evaluate how various market structures -- including market behavior, ancillary services, and changing fleet compositions -- affect net revenues in this ERCOT-like system. In most production cost modeling exercises, resources are assumed to offer their marginal capabilities at marginal costs. Although this assumption is reasonable for feasibility studies and long-term planning, it does not adequately consider the market behaviors that impact revenue sufficiency. In this work, we simulate a limited set of market participant strategic bidding behaviors by means of different sets of markups; these markups are applied to the true production costs of all gas generators, which are the most prominent generators in ERCOT. Results show that markups can help generators increase their net revenues overall, although net revenues may increase or decrease depending on the technology and the year under study. Results also confirm that conventional, variable-cost-based production cost simulations do not capture prices accurately, and this particular feature calls for proxies for strategic behaviors (e.g., markups) and more accurate representations of how electricity markets work. The

  4. Na+ channel β subunits: Overachievers of the ion channel family

    Directory of Open Access Journals (Sweden)

    William J Brackenbury

    2011-09-01

    Full Text Available Voltage gated Na+ channels (VGSCs in mammals contain a pore-forming α subunit and one or more β subunits. There are five mammalian β subunits in total: β1, β1B, β2, β3, and β4, encoded by four genes: SCN1B-SCN4B. With the exception of the SCN1B splice variant, β1B, the β subunits are type I topology transmembrane proteins. In contrast, β1B lacks a transmembrane domain and is a secreted protein. A growing body of work shows that VGSC β subunits are multifunctional. While they do not form the ion channel pore, β subunits alter gating, voltage-dependence, and kinetics of VGSC α subunits and thus regulate cellular excitability in vivo. In addition to their roles in channel modulation, β subunits are members of the immunoglobulin (Ig superfamily of cell adhesion molecules (CAMs and regulate cell adhesion and migration. β subunits are also substrates for sequential proteolytic cleavage by secretases. An example of the multifunctional nature of β subunits is β1, encoded by SCN1B, that plays a critical role in neuronal migration and pathfinding during brain development, and whose function is dependent on Na+ current and γ-secretase activity. Functional deletion of SCN1B results in Dravet Syndrome, a severe and intractable pediatric epileptic encephalopathy. β subunits are emerging as key players in a wide variety of pathophysiologies, including epilepsy, cardiac arrhythmia, multiple sclerosis, Huntington’s disease, neuropsychiatric disorders, neuropathic and inflammatory pain, and cancer. β subunits mediate multiple signaling pathways on different timescales, regulating electrical excitability, adhesion, migration, pathfinding, and transcription. Importantly, some β subunit functions may operate independent of α subunits. Thus, β subunits perform critical roles during development and disease. As such, they may prove useful in disease diagnosis and therapy.

  5. Localisation of main and ancillary foramina within the mesial and distal roots of the first lower molars

    Directory of Open Access Journals (Sweden)

    Jovanović-Medojević Milica

    2005-01-01

    Full Text Available Introduction. Understanding the morphology of the root canal system, and especially its apical third, represents the basic precondition for the successful treatment of diseased pulp and the apical endodontium. Aim. The aim of this study was to precisely locate the main and ancillary foramina in the mesial and distal first lower molars. Method. One hundred extracted first lower molars, originating from persons of both sexes and three different age groups, were used in the study. Results. The analysis of the sampled molars’ apical third was carried out using a binocular magnifier and a digital X-ray scanner (Trophy. The results showed that the main mesial and distal root foramina were located mostly on the distal surface. The ancillary mesial and distal root foramina were located at the lingual end, in most cases. Statistical analysis demonstrated the congruence of results achieved using the binocular magnifier and digital x-ray in 100% of cases if the main foramen is located on the very top of the mesial root (χ2 =17.23; p<0.001, and in 92.9% of cases if the main foramen is localised on the very top of the distal root of the first lower molar (χ2 =12.07; p<0.001. Conclusion. The most common localisation of the main foramina for all age categories and in both mesial and distal roots is on the distal surface of the root. The greatest number of ancillary foramina was observed in the youngest age category, while they were localised most often on the lingual side of the mesial and distal root.

  6. From a bundled energy-capacity pricing model to an energy-capacity-ancillary services pricing model

    Energy Technology Data Exchange (ETDEWEB)

    Raineri, Ricardo; Arce, Raul; Salamanca, Carlos [Departamento de Ingenieria Industrial y de Sistemas, Pontificia Universidad Catolica de Chile, Casilla 306, Correo 22, Santiago (Chile); Rios, Sebastian [Departamento de Ingenieria Electrica, Pontificia Universidad Catolica de Chile, Casilla 306, Correo 22, Santiago (Chile)

    2008-08-15

    In this paper, we extend the Chilean power generation pricing mechanism, with capacity and energy payments, to one where ancillary services (AS), as frequency regulation and voltage control, are explicitly recognized. Adequacy and security attributes of the electric system and the public good characteristics of AS are set within the payment structure to distribute the financing of AS among those who benefit from their provision. The contribution to finance the provision of AS is determined assessing the value assigned to the system security by each agent, following what's an efficient pricing mechanism in the presence of public goods. (author)

  7. Methodology and forecast products for the optimal offering of ancillary services from wind in a market environment

    DEFF Research Database (Denmark)

    Bacher, Peder; Madsen, Henrik; Pinson, Pierre

    of wind power for example in the planning of ancillary power services, where the level of available wind power with a high degree of certainty is important to know. The presented extreme value models are applied to negative forecast residuals from state-of-the-art wind power forecast software...... of extreme weather induced phenomena, for example extreme water levels in a river, wind levels or at sea for design of dykes (de Haan and de Ronde, 1998). In insurance and finance the extreme value modelling is widespread (Embrechts et al., 1997). Extreme value statistics for energy and power applications...

  8. New dyads using (metallo)porphyrins as ancillary ligands in polypyridine ruthenium complexes. Synthesis and electronic properties.

    Science.gov (United States)

    Lachaud, Fabien; Jeandon, Christophe; Monari, Antonio; Assfeld, Xavier; Beley, Marc; Ruppert, Romain; Gros, Philippe C

    2012-11-07

    Porphyrins bearing enaminoketones at their periphery have been used as ancillary ligands in ruthenium complexes. Free base, nickel and zinc porphyrins were successfully coordinated to Ru(bpy)(2)Cl(2) under microwave irradiation. The positive contribution of the ruthenium complex was demonstrated by the complexes' wide absorption domains that covered the 500-600 nm region where the parent porphyrins did not absorb. Electrochemical as well as computational data revealed an efficient electronic communication between the porphyrins and the ruthenium cation in the dyads.

  9. Prefoldin Subunits Are Protected from Ubiquitin-Proteasome System-mediated Degradation by Forming Complex with Other Constituent Subunits*

    Science.gov (United States)

    Miyazawa, Makoto; Tashiro, Erika; Kitaura, Hirotake; Maita, Hiroshi; Suto, Hiroo; Iguchi-Ariga, Sanae M. M.; Ariga, Hiroyoshi

    2011-01-01

    The molecular chaperone prefoldin (PFD) is a complex comprised of six different subunits, PFD1-PFD6, and delivers newly synthesized unfolded proteins to cytosolic chaperonin TRiC/CCT to facilitate the folding of proteins. PFD subunits also have functions different from the function of the PFD complex. We previously identified MM-1α/PFD5 as a novel c-Myc-binding protein and found that MM-1α suppresses transformation activity of c-Myc. However, it remains unclear how cells regulate protein levels of individual subunits and what mechanisms alter the ratio of their activities between subunits and their complex. In this study, we found that knockdown of one subunit decreased protein levels of other subunits and that transfection of five subunits other than MM-1α into cells increased the level of endogenous MM-1α. We also found that treatment of cells with MG132, a proteasome inhibitor, increased the level of transfected/overexpressed MM-1α but not that of endogenous MM-1α, indicating that overexpressed MM-1α, but not endogenous MM-1α, was degraded by the ubiquitin proteasome system (UPS). Experiments using other PFD subunits showed that the UPS degraded a monomer of PFD subunits, though extents of degradation varied among subunits. Furthermore, the level of one subunit was increased after co-transfection with the respective subunit, indicating that there are specific combinations between subunits to be stabilized. These results suggest mutual regulation of protein levels among PFD subunits and show how individual subunits form the PFD complex without degradation. PMID:21478150

  10. Liposome-Based Adjuvants for Subunit Vaccines: Formulation Strategies for Subunit Antigens and Immunostimulators

    DEFF Research Database (Denmark)

    Schmidt, Signe Tandrup; Foged, Camilla; Korsholm, Karen Smith;

    2016-01-01

    for which no effective vaccines exist. The subunit vaccine technology exploits pathogen subunits as antigens, e.g., recombinant proteins or synthetic peptides, allowing for highly specific immune responses against the pathogens. However, such antigens are usually not sufficiently immunogenic to induce......The development of subunit vaccines has become very attractive in recent years due to their superior safety profiles as compared to traditional vaccines based on live attenuated or whole inactivated pathogens, and there is an unmet medical need for improved vaccines and vaccines against pathogens...... been licensed for use in human vaccines, and they mainly stimulate humoral immunity. Thus, there is an unmet demand for the development of safe and efficient adjuvant systems that can also stimulate cell-mediated immunity (CMI). Adjuvants constitute a heterogeneous group of compounds, which can broadly...

  11. Secure provision of reactive power ancillary services in competitive electricity markets

    Science.gov (United States)

    El-Samahy, Ismael

    decoupled and assumed to be fixed during the reactive power dispatch procedures; however, the effect of reactive power on real power is considered in the model by calculating the required reduction in real power output of a generator due to an increase in its reactive power supply. In this case, real power generation is allowed to be rescheduled, within given limits, from the already dispatched levels obtained from the energy market clearing process. The proposed dispatch model achieves the main objective of an ISO in a competitive electricity market, which is to provide the required reactive power support from generators at least cost while ensuring a secure operation of the power system. The proposed reactive power procurement and dispatch models capture both the technical and economic aspects of power system operation in competitive electricity markets; however, from an optimization point of view, these models represent non-convex mixed integer non-linear programming (MINLP) problems due to the presence of binary variables associated with the different regions of reactive power operation in a synchronous generator. Such MINLP optimization problems are difficult to solve, especially for an actual power system. A novel Generator Reactive Power Classification (GRPC) algorithm is proposed in this thesis to address this issue, with the advantage of iteratively solving the optimization models as a series of non-linear programming (NLP) sub-problems. The proposed reactive power procurement and dispatch models are implemented and tested on the CIGRE 32-bus system, with several case studies that represent different practical operating scenarios. The developed models are also compared with other approaches for reactive power provision, and the results demonstrate the robustness and effectiveness of the proposed model. The results clearly reveal the main features of the proposed models for optimal provision of reactive power ancillary service, in order to suit the requirements of

  12. Fine needle biopsy with cytology in paediatrics: the importance of a multidisciplinary approach and the role of ancillary techniques.

    Science.gov (United States)

    Barroca, H; Bom-Sucesso, M

    2014-02-01

    Fine needle biopsy (FNB) with cytology has long been regarded as an excellent technique as the first choice for diagnosing adult tumours. Being an inexpensive minimally invasive technique with high accuracy and diagnostic immediacy through rapid on-site evaluation, it is also ideal for implementation in the paediatric setting, particularly in developing countries. Furthermore, it allows complementary and advanced procedures such as flow cytometry, polymerase chain reaction (PCR) or fluorescence in situ hybridization (FISH), among others, which enhances the diagnostic capacity of this technique and gives it a key role in risk stratification and therapeutic decision-making for several tumours. The advantages of FNB are optimized in the setting of a multidisciplinary team where cytologist, clinician and radiologist play leading roles. Paediatric tumours are rare and most ancillary techniques are cost-effective but complex to be implemented in small centres with limited experience in paediatric pathology. Therefore reference centres are essential, in order to establish teams with extensive experience and expertise. Hence, any child with a suspected malignancy should be directly referred to a paediatric oncology unit. Focusing on a practical approach to the assessment of paediatric lymphadenopathies and non-central nervous system solid tumours we review the effectiveness of FNB as applied concurrently with ancillary techniques in a multidisciplinary approach to the diagnosis, prognosis and therapeutic decisions of paediatric tumours and tumour-like lesions.

  13. Use of GIS and ancillary variables to predict volatile organic compound and nitrogen dioxide levels at unmonitored locations

    Science.gov (United States)

    Smith, Luther; Mukerjee, Shaibal; Gonzales, Melissa; Stallings, Casson; Neas, Lucas; Norris, Gary; Özkaynak, Halûk

    In late 1999, passive air sampling of nitrogen dioxide (NO 2) and volatile organic compounds was conducted at 22 school locations and two intensive sites in El Paso, Texas. Our goal was to predict concentrations of NO 2 and benzene, toluene, ethylbenzene, o-xylene, and m, p-xylene at a total of 55 schools. The predictive equations were developed by regressing the passive monitor measurements at the 22 monitored schools on land-use variables derived from a geographic information system (GIS). These GIS-based ancillary variables included distance to the nearest border crossing, elevation, population density, distance to roads with specified traffic volumes, traffic intensity around the schools, and distance to the nearest petroleum facility. The reliability of the predictive equations was assessed at the two intensive monitoring sites. For all pollutants, the most useful predictive ancillary variables were elevation, population density, distance to a border crossing, and distance to a petroleum facility. For estimating NO 2, traffic intensity was also important.

  14. On combining multi-normalization and ancillary measures for the optimal score level fusion of fingerprint and voice biometrics

    Science.gov (United States)

    Mohammed Anzar, Sharafudeen Thaha; Sathidevi, Puthumangalathu Savithri

    2014-12-01

    In this paper, we have considered the utility of multi-normalization and ancillary measures, for the optimal score level fusion of fingerprint and voice biometrics. An efficient matching score preprocessing technique based on multi-normalization is employed for improving the performance of the multimodal system, under various noise conditions. Ancillary measures derived from the feature space and the score space are used in addition to the matching score vectors, for weighing the modalities, based on their relative degradation. Reliability (dispersion) and the separability (inter-/intra-class distance and d-prime statistics) measures under various noise conditions are estimated from the individual modalities, during the training/validation stage. The `best integration weights' are then computed by algebraically combining these measures using the weighted sum rule. The computed integration weights are then optimized against the recognition accuracy using techniques such as grid search, genetic algorithm and particle swarm optimization. The experimental results show that, the proposed biometric solution leads to considerable improvement in the recognition performance even under low signal-to-noise ratio (SNR) conditions and reduces the false acceptance rate (FAR) and false rejection rate (FRR), making the system useful for security as well as forensic applications.

  15. Active Power Control of Wind Turbines for Ancillary Services: A Comparison of Pitch and Torque Control Methodologies

    Energy Technology Data Exchange (ETDEWEB)

    Aho, Jacob; Fleming, Paul; Pao, Lucy Y.

    2016-08-01

    As wind energy generation becomes more prevalent in some regions, there is increased demand for wind power plants to provide ancillary services, which are essential for grid reliability. This paper compares two different wind turbine control methodologies to provide active power control (APC) ancillary services, which include derating or curtailing power generation, providing automatic generation control (AGC), and providing primary frequency control (PFC). The torque APC controller provides all power control through the power electronics whereas the pitch APC controller uses the blade pitch actuators as the primary means of power control. These controllers are simulated under various wind conditions with different derating set points and AGC participation levels. The metrics used to compare their performance are the damage equivalent loads (DELs) induced on the structural components and AGC performance metrics, which are used to determine the payments for AGC services by system operators in the United States. The simulation results show that derating the turbine reduces structural loads for both control methods, with the APC pitch control providing larger reductions in DELs, lower AGC performance scores, and higher root-mean-square pitch rates. Providing AGC increases the structural loads when compared to only derating the turbine, but even the AGC DELs are generally lower than those of the baseline control system. The torque APC control methodology also allows for more sustained PFC responses under certain derating conditions.

  16. Mitigation costs, distributional effects, and ancillary benefits of carbon policies in the Nordic countries, the U.K., and Ireland

    Energy Technology Data Exchange (ETDEWEB)

    Bye, B; Rosendahl, K.E. [Research Department, Statistics Norway, P.O. Box 8131 Dep., 0033 Oslo (Norway); Kverndokk, S. [Ragnar Frisch Centre for Economic Research, Gaustadalleen 21, 0349 Oslo (Norway)

    2002-07-01

    This paper provides a survey of top-down modelling analyses of carbon (C) abatement mitigation costs, distributional effects and ancillary benefits in the Nordic countries, the U.K. and Ireland. Special emphasis is placed on the effects of revenue recycling and tax exemptions. According to the analyses, modest emissions reductions can be met without substantial costs for the countries studied, and a strong double dividend is found in some analyses. The gross domestic product (GDP) or welfare effects are mostly in the range of -0.4 and 1.2% when C emissions are reduced by 20-30 per cent. Lowest costs are obtained without tax exemptions and with tax revenues used to reduce distortionary taxes. Ancillary benefits are mostly in the range 35-80/MgC{sup -1}, i.e., about the same order of magnitude as the mitigation costs. Distributional effects are mostly regressive, unless the tax revenues are distributed in lump-sum fashion with equal transfers to each household.

  17. STEADY-STATE TRANSCRIPT LEVELS OF CYTOCHROME-C-OXIDASE GENES DURING HUMAN MYOGENESIS INDICATE SUBUNIT SWITCHING OF SUBUNIT VIA AND COEXPRESSION OF SUBUNIT VIIA ISOFORMS

    NARCIS (Netherlands)

    TAANMAN, JW; HERZBERG, NH; DEVRIES, H; BOLHUIS, PA; VANDENBOGERT, C

    1992-01-01

    Steady-state levels of the mitochondrial rRNAs, of mRNAs for mitochondrially and nuclear-encoded subunits of cytochrome c oxidase and for the beta-subunit of ATP synthase were assessed by Northern blot hybridizations during the in vitro differentiation of human myoblasts. Transcript levels of the so

  18. 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.

  19. Subunit structure of the phycobiliproteins of blue-green algae.

    Science.gov (United States)

    Glazer, A N; Cohen-Bazire, G

    1971-07-01

    The phycobiliproteins of the blue-green algae Synechococcus sp. and Aphanocapsu sp. were characterized with respect to homogeneity, isoelectric point, and subunit composition. Each of the biliproteins consisted of two different noncovalently associated subunits, with molecular weights of about 20,000 and 16,000 for phycocyanin, 17,500 and 15,500 for allophycocyanin, and 22,000 and 20,000 for phycoerythrin. Covalently bound chromophore was associated with each subunit.

  20. Work environments of different types of nursing subunits.

    Science.gov (United States)

    Leatt, P; Schneck, R

    1982-11-01

    Based upon organizational theory, the purpose of this research was to identify and describe similarities and differences in the work environments of nine different types of nursing subunits (intensive care, medical, surgical, psychiatric, auxiliary, rehabilitation, rural, paediatric and obstetrical) in hospitals. Six measures of nursing subunit environment were developed: these included measures of nursing subunit autonomy, and the complexity and pervasiveness of other medical and hospital groups interacting with the nursing subunit. Data were collected by questionnaire from headnurses in 157 nursing subunits located in 24 hospitals in Alberta, Canada. The results indicated that the types of nursing subunits were similar in their degree of autonomy from both physicians and administration in the larger context in which they were located but were significantly different in terms of number and heterogeneity of groups outside nurses with which they interacted and the extent to which such groups pervaded the subunits. For example, intensive care units appeared as the type of nursing subunit with the greatest need for interaction with physicians, paramedics, hotel services and so on, whereas, psychiatric subunits appeared to be the least dependent on groups outside nursing in the hospital. These findings have implications for the management practices and educational programme for nursing.

  1. Thermostable Subunit Vaccines for Pulmonary Delivery

    DEFF Research Database (Denmark)

    Foged, Camilla

    2016-01-01

    -administrable, can be distributed independently of functioning freezers and refrigerators, and can be designed to induce mucosal and/or cell-mediated immunity, which is attractive for a number of diseases requiring stimulation of local mucosal immunity for protection. However, the design and delivery of thermostable...... dry powder-based vaccines represents a technological challenge: It calls for careful formulation and dosage form design, combined with cheap and efficient delivery devices, which must be engineered via a thorough understanding of the physiological barrier and the requirements for induction of mucosal...... immunity. Here, I review state of the art and perspectives in formulation design and processing methods for powder-based subunit vaccines intended for pulmonary administration, and present dry powder inhaler technologies suitable for translating these vaccines into clinical trials....

  2. Risk-constrained dynamic self-scheduling of a pumped-storage plant in the energy and ancillary service markets

    Energy Technology Data Exchange (ETDEWEB)

    Kazempour, S. Jalal; Moghaddam, M. Parsa; Haghifam, M.R.; Yousefi, G.R. [Department of Electrical Engineering, Tarbiat Modares University (TMU), Tehran (Iran)

    2009-05-15

    This work addresses a new framework for self-scheduling of an individual price-taker pumped-storage plant in a day-ahead (DA) market. The goal is achieving the best trade-off between the expected profit and the risks when the plant participates in DA energy, spinning reserve and regulation markets. In this paper, a set of uncertainties including price forecasting errors and also the uncertainty of power delivery requests in the ancillary service markets are contemplated. Considering these uncertainties, a new approach is proposed which is called dynamic self-scheduling (DSS). This risk-constrained dynamic self-scheduling problem is therefore formulated and solved as a mixed integer programming (MIP) problem. Numerical results for a case study are discussed. (author)

  3. The business of medicine: how to overcome financial obstacles and secure financing for your private practice and ancillary services business.

    Science.gov (United States)

    Nayor, David

    2012-01-01

    Doctors across the country who operate private medical practices are facing increasing financial obstacles, namely shrinking income as a result of rising costs and lower reimbursements. In addition, as hospitals have become overburdened many physicians have opened up private surgical centers; magnetic resonance imaging and computed tomography and positron emission tomography scanning facilities; pathology labs; colonoscopy/endoscopy suites; lithotripsy centers; and other medical businesses typically performed within the hospital. Moreover, many doctors seek loans to purchase existing practices or for their capital contribution in medical partnerships. The past decade has thus seen a significant increase in the number of doctors taking out small business loans. Indeed, banks view the healthcare industry as a large growth market. This article includes practical information, advice, and resources to help doctors to secure bank financing for their practices, ancillary services business, real estate, and equipment on the best possible market terms.

  4. Profile of Hashimoto's Thyroiditis in Sri Lankans: Is There an Increased Risk of Ancillary Pathologies in Hashimoto's Thyroiditis?

    Directory of Open Access Journals (Sweden)

    Eranga Himalee Siriweera

    2010-01-01

    Full Text Available Hashimoto's thyroiditis has been reported to be associated with many neoplastic and nonneoplastic thyroid pathologies. This retrospective study aims to determine the demographic profile of Hashimoto's thyroiditis in Sri Lankans, document ancillary pathologies in Hashimoto's thyroiditis, and determine whether there is an increased risk of occurrence of malignancies, benign neoplasms, and nonneoplastic benign lesions in Hashimoto's thyroiditis by comparing with thyroids showing multinodular goiters, follicular adenomas, and colloid nodules. The mean age of Hashimoto's thyroiditis is 43.3 years with the majority in the 41 to 60 year age group and a female to male ratio of 10.3 : 1. This study revealed a statistically significant increase of thyroid malignancies in association with Hashimoto's thyroiditis. The association of Papillary carcinoma, Non-Hodgkin's lymphoma, and Hurthle cell adenoma with Hashimoto's thyroiditis was statistically significant.

  5. Profile of Hashimoto's Thyroiditis in Sri Lankans: Is There an Increased Risk of Ancillary Pathologies in Hashimoto's Thyroiditis?

    Science.gov (United States)

    Siriweera, Eranga Himalee; Ratnatunga, Neelakanthi Vajira Illangakoon

    2010-10-10

    Hashimoto's thyroiditis has been reported to be associated with many neoplastic and nonneoplastic thyroid pathologies. This retrospective study aims to determine the demographic profile of Hashimoto's thyroiditis in Sri Lankans, document ancillary pathologies in Hashimoto's thyroiditis, and determine whether there is an increased risk of occurrence of malignancies, benign neoplasms, and nonneoplastic benign lesions in Hashimoto's thyroiditis by comparing with thyroids showing multinodular goiters, follicular adenomas, and colloid nodules. The mean age of Hashimoto's thyroiditis is 43.3 years with the majority in the 41 to 60 year age group and a female to male ratio of 10.3 : 1. This study revealed a statistically significant increase of thyroid malignancies in association with Hashimoto's thyroiditis. The association of Papillary carcinoma, Non-Hodgkin's lymphoma, and Hurthle cell adenoma with Hashimoto's thyroiditis was statistically significant.

  6. Dynamic regulation of β1 subunit trafficking controls vascular contractility.

    Science.gov (United States)

    Leo, M Dennis; Bannister, John P; Narayanan, Damodaran; Nair, Anitha; Grubbs, Jordan E; Gabrick, Kyle S; Boop, Frederick A; Jaggar, Jonathan H

    2014-02-11

    Ion channels composed of pore-forming and auxiliary subunits control physiological functions in virtually all cell types. A conventional view is that channels assemble with their auxiliary subunits before anterograde plasma membrane trafficking of the protein complex. Whether the multisubunit composition of surface channels is fixed following protein synthesis or flexible and open to acute and, potentially, rapid modulation to control activity and cellular excitability is unclear. Arterial smooth muscle cells (myocytes) express large-conductance Ca(2+)-activated potassium (BK) channel α and auxiliary β1 subunits that are functionally significant modulators of arterial contractility. Here, we show that native BKα subunits are primarily (∼95%) plasma membrane-localized in human and rat arterial myocytes. In contrast, only a small fraction (∼10%) of total β1 subunits are located at the cell surface. Immunofluorescence resonance energy transfer microscopy demonstrated that intracellular β1 subunits are stored within Rab11A-postive recycling endosomes. Nitric oxide (NO), acting via cGMP-dependent protein kinase, and cAMP-dependent pathways stimulated rapid (≤1 min) anterograde trafficking of β1 subunit-containing recycling endosomes, which increased surface β1 almost threefold. These β1 subunits associated with surface-resident BKα proteins, elevating channel Ca(2+) sensitivity and activity. Our data also show that rapid β1 subunit anterograde trafficking is the primary mechanism by which NO activates myocyte BK channels and induces vasodilation. In summary, we show that rapid β1 subunit surface trafficking controls functional BK channel activity in arterial myocytes and vascular contractility. Conceivably, regulated auxiliary subunit trafficking may control ion channel activity in a wide variety of cell types.

  7. Liposome-Based Adjuvants for Subunit Vaccines: Formulation Strategies for Subunit Antigens and Immunostimulators

    DEFF Research Database (Denmark)

    Schmidt, Signe Tandrup; Foged, Camilla; Korsholm, Karen Smith

    2016-01-01

    be classified into delivery systems or immunostimulators. Liposomes are versatile delivery systems for antigens, and they can carefully be customized towards desired immune profiles by combining them with immunostimulators and optimizing their composition, physicochemical properties and antigen-loading mode......The development of subunit vaccines has become very attractive in recent years due to their superior safety profiles as compared to traditional vaccines based on live attenuated or whole inactivated pathogens, and there is an unmet medical need for improved vaccines and vaccines against pathogens...... of immunostimulators and antigens, respectively, into liposomes, and the choice of immunostimulator should ideally be based on knowledge regarding the specific PRR expression profile of the target APCs. Here, we review state-of-the-art formulation approaches employed for the inclusion of immunostimulators and subunit...

  8. The Role of Liquid Based Cytology and Ancillary Techniques in the Peritoneal Washing Analysis: Our Institutional Experience

    Science.gov (United States)

    Rossi, Esther; Bizzarro, Tommaso; Martini, Maurizio; Longatto-Filho, Adhemar; Schmitt, Fernando; Fagotti, Anna; Scambia, Giovanni; Zannoni, Gian Franco

    2017-01-01

    Background The cytological analysis of peritoneal effusions serves as a diagnostic and prognostic aid for either primary or metastatic diseases. Among the different cytological preparations, liquid based cytology (LBC) represents a feasible and reliable method ensuring also the application of ancillary techniques (i.e immunocytochemistry-ICC and molecular testing). Methods We recorded 10348 LBC peritoneal effusions between January 2000 and December 2014. They were classified as non-diagnostic (ND), negative for malignancy-NM, atypical-suspicious for malignancy-SM and positive for malignancy-PM. Results The cytological diagnosis included 218 ND, 9.035 NM, 213 SM and 882 PM. A total of 8048 (7228 NM, 115SM, 705 PM) cases with histological follow-up were included. Our NM included 21 malignant and 7207 benign histological diagnoses. Our 820 SMs+PMs were diagnosed as 107 unknown malignancies (30SM and 77PM), 691 metastatic lesions (81SM and 610PM), 9 lymphomas (2SM and 7PM), 9 mesotheliomas (1SM and 8SM), 4 sarcomas (1SM and 3PM). Primary gynecological cancers contributed with 64% of the cases. We documented 97.4% sensitivity, 99.9% specificity, 98% diagnostic accuracy, 99.7% negative predictive value (NPV) and 99.7% positive predictive value (PPV). Furthermore, the morphological diagnoses were supported by either 173 conclusive ICC results or 50 molecular analyses. Specifically the molecular testing was performed for the EGFR and KRAS mutational analysis based on the previous or contemporary diagnoses of Non Small Cell Lung Cancer (NSCLC) and colon carcinomas. We identified 10 EGFR in NSCCL and 7 KRAS mutations on LBC stored material. Conclusions Peritoneal cytology is an adjunctive tool in the surgical management of tumors mostly gynecological cancers. LBC maximizes the application of ancillary techniques such as ICC and molecular analysis with feasible diagnostic and predictive yields also in controversial cases. PMID:28099523

  9. Liposome-Based Adjuvants for Subunit Vaccines: Formulation Strategies for Subunit Antigens and Immunostimulators

    Directory of Open Access Journals (Sweden)

    Signe Tandrup Schmidt

    2016-03-01

    Full Text Available The development of subunit vaccines has become very attractive in recent years due to their superior safety profiles as compared to traditional vaccines based on live attenuated or whole inactivated pathogens, and there is an unmet medical need for improved vaccines and vaccines against pathogens for which no effective vaccines exist. The subunit vaccine technology exploits pathogen subunits as antigens, e.g., recombinant proteins or synthetic peptides, allowing for highly specific immune responses against the pathogens. However, such antigens are usually not sufficiently immunogenic to induce protective immunity, and they are often combined with adjuvants to ensure robust immune responses. Adjuvants are capable of enhancing and/or modulating immune responses by exposing antigens to antigen-presenting cells (APCs concomitantly with conferring immune activation signals. Few adjuvant systems have been licensed for use in human vaccines, and they mainly stimulate humoral immunity. Thus, there is an unmet demand for the development of safe and efficient adjuvant systems that can also stimulate cell-mediated immunity (CMI. Adjuvants constitute a heterogeneous group of compounds, which can broadly be classified into delivery systems or immunostimulators. Liposomes are versatile delivery systems for antigens, and they can carefully be customized towards desired immune profiles by combining them with immunostimulators and optimizing their composition, physicochemical properties and antigen-loading mode. Immunostimulators represent highly diverse classes of molecules, e.g., lipids, nucleic acids, proteins and peptides, and they are ligands for pattern-recognition receptors (PRRs, which are differentially expressed on APC subsets. Different formulation strategies might thus be required for incorporation of immunostimulators and antigens, respectively, into liposomes, and the choice of immunostimulator should ideally be based on knowledge regarding the

  10. Structure of the archaeal Cascade subunit Csa5: relating the small subunits of CRISPR effector complexes.

    Science.gov (United States)

    Reeks, Judith; Graham, Shirley; Anderson, Linzi; Liu, Huanting; White, Malcolm F; Naismith, James H

    2013-05-01

    The Cascade complex for CRISPR-mediated antiviral immunity uses CRISPR RNA (crRNA) to target invading DNA species from mobile elements such as viruses, leading to their destruction. The core of the Cascade effector complex consists of the Cas5 and Cas7 subunits, which are widely conserved in prokaryotes. Cas7 binds crRNA and forms the helical backbone of Cascade. Many archaea encode a version of the Cascade complex (denoted Type I-A) that includes a Csa5 (or small) subunit, which interacts weakly with the core proteins. Here, we report the crystal structure of the Csa5 protein from Sulfolobus solfataricus. Csa5 comprises a conserved α-helical domain with a small insertion consisting of a weakly conserved β-strand domain. In the crystal, the Csa5 monomers have multimerized into infinite helical threads. At each interface is a strictly conserved intersubunit salt bridge, deletion of which disrupts multimerization. Structural analysis indicates a shared evolutionary history among the small subunits of the CRISPR effector complexes. The same α-helical domain is found in the C-terminal domain of Cse2 (from Type I-E Cascade), while the N-terminal domain of Cse2 is found in Cmr5 of the CMR (Type III-B) effector complex. As Cmr5 shares no match with Csa5, two possibilities present themselves: selective domain loss from an ancestral Cse2 to create two new subfamilies or domain fusion of two separate families to create a new Cse2 family. A definitive answer awaits structural studies of further small subunits from other CRISPR effector complexes.

  11. Prediction of spatial soil property information from ancillary sensor data using ordinary linear regression: Model derivations, residual assumptions and model validation tests

    Science.gov (United States)

    Geospatial measurements of ancillary sensor data, such as bulk soil electrical conductivity or remotely sensed imagery data, are commonly used to characterize spatial variation in soil or crop properties. Geostatistical techniques like kriging with external drift or regression kriging are often use...

  12. Microwave-assisted synthesis and complexation of luminescent cyanobipyridyl-zinc(II) bis(thiolate) complexes with intrinsic and ancillary photophysical tunability.

    Science.gov (United States)

    Bagley, Mark C; Lin, Zhifan; Pope, Simon J A

    2010-04-07

    A series of cyanobipyridine-derived zinc(II) bis(thiolate) complexes are prepared rapidly and efficiently by a microwave-assisted cross-coupling/complexation sequence and display luminescence that can be modulated using intrinsic functionality and ancillary ligands.

  13. 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.

  14. The subunit composition and function of mammalian cytochrome c oxidase.

    Science.gov (United States)

    Kadenbach, Bernhard; Hüttemann, Maik

    2015-09-01

    Cytochrome c oxidase (COX) from mammals and birds is composed of 13 subunits. The three catalytic subunits I-III are encoded by mitochondrial DNA, the ten nuclear-coded subunits (IV, Va, Vb, VIa, VIb, VIc, VIIa, VIIb, VIIc, VIII) by nuclear DNA. The nuclear-coded subunits are essentially involved in the regulation of oxygen consumption and proton translocation by COX, since their removal or modification changes the activity and their mutation causes mitochondrial diseases. Respiration, the basis for ATP synthesis in mitochondria, is differently regulated in organs and species by expression of tissue-, developmental-, and species-specific isoforms for COX subunits IV, VIa, VIb, VIIa, VIIb, and VIII, but the holoenzyme in mammals is always composed of 13 subunits. Various proteins and enzymes were shown, e.g., by co-immunoprecipitation, to bind to specific COX subunits and modify its activity, but these interactions are reversible, in contrast to the tightly bound 13 subunits. In addition, the formation of supercomplexes with other oxidative phosphorylation complexes has been shown to be largely variable. The regulatory complexity of COX is increased by protein phosphorylation. Up to now 18 phosphorylation sites have been identified under in vivo conditions in mammals. However, only for a few phosphorylation sites and four nuclear-coded subunits could a specific function be identified. Research on the signaling pathways leading to specific COX phosphorylations remains a great challenge for understanding the regulation of respiration and ATP synthesis in mammalian organisms. This article reviews the function of the individual COX subunits and their isoforms, as well as proteins and small molecules interacting and regulating the enzyme.

  15. Regulation of BK channels by auxiliary γ subunits

    Directory of Open Access Journals (Sweden)

    Jiyuan eZhang

    2014-10-01

    Full Text Available The large-conductance, calcium- and voltage-activated potassium (BK channel has the largest single-channel conductance among potassium channels and can be activated by both membrane depolarization and increases in intracellular calcium concentration. BK channels consist of pore-forming, voltage- and calcium-sensing α subunits, either alone or in association with regulatory subunits. BK channels are widely expressed in various tissues and cells including both excitable and non-excitable cells and display diverse biophysical and pharmacological characteristics. This diversity can be explained in part by posttranslational modifications and alternative splicing of the α subunit, which is encoded by a single gene, KCNMA1, as well as by tissue-specific β subunit modulation. Recently, a leucine-rich repeat-containing membrane protein, LRRC26, was found to interact with BK channels and cause an unprecedented large negative shift (~-140 mV in the voltage dependence of the BK channel activation. LRRC26 allows BK channels to open even at near-physiological calcium concentration and membrane voltage in non-excitable cells. Three LRRC26-related proteins, LRRC52, LRRC55, and LRRC38, were subsequently identified as BK channel modulators. These LRRC proteins are structurally and functionally distinct from the BK channel β subunits and were designated as γ subunits. The discovery of the γ subunits adds a new dimension to BK channel regulation and improves our understanding of the physiological functions of BK channels in various tissues and cell types. Unlike BK channel β subunits, which have been intensively investigated both mechanistically and physiologically, our understanding of the γ subunits is very limited at this stage. This article reviews the structure, modulatory mechanisms, physiological relevance, and potential therapeutic implications of γ subunits as they are currently understood.

  16. Identification of a novel HMW glutenin subunit and comparison of its amino acid sequence with those of homologous subunits

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Aegilops tauschii is the donor of the D genome of common wheat (Triticum aestivum). Genetic variation of HMW glutenin subunits encoded by the Glu-1Dt locus of Ae. tauschii has been found to be higher than that specified by the Glu-1D locus in common wheat. In the present note, we report the identification of a novel HMW glutenin subunit, Dy13t, from Ae. tauschii. The newly identified subunit possessed an electrophoretic mobility that was faster than that of the Dy12 subunit of common wheat. The complete ORF of encoding the Dy13t subunit contained 624 codons (excluding the stop codons). The amino acid sequence deduced from the Dy13t gene ORF was the shortest among those of the previously reported subunits derived by the D genome. A further comparison of Dy13t amino acid sequence with those of the subunits characterized from the A, B, D, R genomes of Triticeae showed that the smaller size of the Dy13t subunit was associated with a reduction in the size of its repetitive domain.

  17. 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.

  18. A fully automatic tool to perform accurate flood mapping by merging remote sensing imagery and ancillary data

    Science.gov (United States)

    D'Addabbo, Annarita; Refice, Alberto; Lovergine, Francesco; Pasquariello, Guido

    2016-04-01

    Flooding is one of the most frequent and expansive natural hazard. High-resolution flood mapping is an essential step in the monitoring and prevention of inundation hazard, both to gain insight into the processes involved in the generation of flooding events, and from the practical point of view of the precise assessment of inundated areas. Remote sensing data are recognized to be useful in this respect, thanks to the high resolution and regular revisit schedules of state-of-the-art satellites, moreover offering a synoptic overview of the extent of flooding. In particular, Synthetic Aperture Radar (SAR) data present several favorable characteristics for flood mapping, such as their relative insensitivity to the meteorological conditions during acquisitions, as well as the possibility of acquiring independently of solar illumination, thanks to the active nature of the radar sensors [1]. However, flood scenarios are typical examples of complex situations in which different factors have to be considered to provide accurate and robust interpretation of the situation on the ground: the presence of many land cover types, each one with a particular signature in presence of flood, requires modelling the behavior of different objects in the scene in order to associate them to flood or no flood conditions [2]. Generally, the fusion of multi-temporal, multi-sensor, multi-resolution and/or multi-platform Earth observation image data, together with other ancillary information, seems to have a key role in the pursuit of a consistent interpretation of complex scenes. In the case of flooding, distance from the river, terrain elevation, hydrologic information or some combination thereof can add useful information to remote sensing data. Suitable methods, able to manage and merge different kind of data, are so particularly needed. In this work, a fully automatic tool, based on Bayesian Networks (BNs) [3] and able to perform data fusion, is presented. It supplies flood maps

  19. NADH dehydrogenase subunit 1 and cytochrome c oxidase subunit I sequences compared for members of the genus Taenia (Cestoda).

    Science.gov (United States)

    Gasser, R B; Zhu, X; McManus, D P

    1999-12-01

    Nine members of the genus Taenia (Taenia taeniaeformis, Taenia hydatigena, Taenia pisiformis, Taenia ovis, Taenia multiceps, Taenia serialis, Taenia saginata, Taenia solium and the Asian Taenia) were characterised by their mitochondrial NADH dehydrogenase subunit 1 gene sequences and their genetic relationships were compared with those derived from the cytochrome c oxidase subunit 1 sequence data. The extent of inter-taxon sequence difference in NADH dehydrogenase subunit 1 (approximately 5.9-30.8%) was usually greater than in cytochrome c oxidase subunit 1 (approximately 2.5-18%). Although topology of the phenograms derived from NADH dehydrogenase subunit 1 and cytochrome c oxidase subunit 1 sequence data differed, there was concordance in that T. multiceps, T. serialis (of canids), T. saginata and the Asian Taenia (of humans) were genetically most similar, and those four members were genetically more similar to T. ovis and T. solium than they were to T. hydatigena and T. pisiformis (of canids) or T. taeniaeformis (of cats). The NADH dehydrogenase subunit 1 sequence data may prove useful in studies of the systematics and population genetic structure of the Taeniidae.

  20. Genetic analysis of the cytoplasmic dynein subunit families.

    Directory of Open Access Journals (Sweden)

    K Kevin Pfister

    2006-01-01

    Full Text Available Cytoplasmic dyneins, the principal microtubule minus-end-directed motor proteins of the cell, are involved in many essential cellular processes. The major form of this enzyme is a complex of at least six protein subunits, and in mammals all but one of the subunits are encoded by at least two genes. Here we review current knowledge concerning the subunits, their interactions, and their functional roles as derived from biochemical and genetic analyses. We also carried out extensive database searches to look for new genes and to clarify anomalies in the databases. Our analysis documents evolutionary relationships among the dynein subunits of mammals and other model organisms, and sheds new light on the role of this diverse group of proteins, highlighting the existence of two cytoplasmic dynein complexes with distinct cellular roles.

  1. Proposal for the award of an industrial services contract for operation of the hostels, apartments and ancillary premises

    CERN Document Server

    2000-01-01

    This document concerns the award of an Industrial Services contract for operation of the hostels, apartments and ancillary premises run by the CERN Housing Service. Following a market survey carried out among 32 firms in ten Member States, a call for tenders (IT-2404/AS/Rev.) was sent on 5 April 2000 to one firm and three consortia in four Member States. By the closing date, CERN had received tenders from the firm and the three consortia. The Finance Committee is invited to agree to the negotiation of a contract with the consortium VIENNA INTERNATIONAL HOTEL MANAGEMENT (AT) - SEREG (CH), the lowest bidder, for an initial period of five years, to enter into force on 1 January 2001, for a total amount of 6 871 850 Swiss francs, not subject to revision until 31 December 2001. The contract will include an option for two one-year extensions beyond the initial five-year period. The consortium has indicated the following distribution by country of the contract value covered by this adjudication proposal: CH-60%, AT-...

  2. Impact of Histopathological Diagnosis with Ancillary Immunohistochemical Studies on Lung Cancer Subtypes Incidence and Survival: A Population-Based Study

    Directory of Open Access Journals (Sweden)

    Andrea Bordoni

    2011-01-01

    Full Text Available Purpose. The aim of this study was to assess the impact of immunohistochemical- (IHC- studies on incidence and survival of lung cancer histotypes. Patients and Methods. Lung cancers occurred in southern Switzerland between 1996 and 2010 were selected by the Ticino Cancer Registry and categorised into adenocarcinoma (AC, squamous-cell-carcinoma (SqCC, small-cell-carcinoma (SmCC, and large-cell carcinoma/non-small-cell lung cancer (LCC/NSCLC. Incidence rates, annual-percentage-change (APC, and two-year overall survival (OS (follow-up: 31.12.2010 were performed. Results. 2467 cases were selected: 997 (40.4% AC; 522 (21.2% LCC/NSCLC, 378 (15.3% SmCC, and 570 (23.1% SqCC. Trend-analysis showed significant increase in AC (APC: 4.6; 95% CI: 3.1; 6.0 and decrease of LCC/NSCLC, with significant joinpoint in 2003 (APC: −14.7; 95% CI: −21.6; −7.1. Improved OS and decreased OS were detected in SqCC and LCC/NSCLC, respectively. Conclusions. This study highlights that diagnosis with ancillary immunohistochemical studies will change incidence and survival of precisely defined lung cancer subtypes. It calls attention to the need for cautious interpretation of studies and clinical trials, where the diagnosis was based on histology unaccompanied by IHC studies, and to the need of standardised diagnostic procedures.

  3. Reducing costs of managing and accessing navigation and ancillary data by relying on the extensive capabilities of NASA's spice system

    Science.gov (United States)

    Semenov, Boris V.; Acton, Charles H., Jr.; Bachman, Nathaniel J.; Elson, Lee S.; Wright, Edward D.

    2005-01-01

    The SPICE system of navigation and ancillary data possesses a number of traits that make its use in modern space missions of all types highly cost efficient. The core of the system is a software library providing API interfaces for storing and retrieving such data as trajectories, orientations, time conversions, and instrument geometry parameters. Applications used at any stage of a mission life cycle can call SPICE APIs to access this data and compute geometric quantities required for observation planning, engineering assessment and science data analysis. SPICE is implemented in three different languages, supported on 20+ computer environments, and distributed with complete source code and documentation. It includes capabilities that are extensively tested by everyday use in many active projects and are applicable to all types of space missions - flyby, orbiters, observatories, landers and rovers. While a customer's initial SPICE adaptation for the first mission or experiment requires a modest effort, this initial effort pays off because adaptation for subsequent missions/experiments is just a small fraction of the initial investment, with the majority of tools based on SPICE requiring no or very minor changes.

  4. Chronic stress, inflammation, and glucose regulation in U.S. Hispanics from the HCHS/SOL Sociocultural Ancillary Study.

    Science.gov (United States)

    McCurley, Jessica L; Mills, Paul J; Roesch, Scott C; Carnethon, Mercedes; Giacinto, Rebeca E; Isasi, Carmen R; Teng, Yanping; Sotres-Alvarez, Daniela; Llabre, Maria M; Penedo, Frank J; Schneiderman, Neil; Gallo, Linda C

    2015-08-01

    Diabetes prevalence is rising rapidly, and diabetes disproportionately affects Hispanics and other underserved groups. Chronic stress may contribute to diabetes risk, but few studies have examined this relationship in U.S. Hispanics. We examined associations of chronic stress with fasting glucose, glucose tolerance, and glycosylated hemoglobin (HbA1c) in Hispanics without diabetes, and also assessed indirect effects of stress through inflammation (CRP). Participants were 3,923 men and women, aged 18-74, without diabetes, from the four U.S. field centers (Bronx, NY; Chicago, IL; Miami, FL; San Diego, CA) of the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) Sociocultural Ancillary study. Participants completed a measure of chronic life stress and a physical exam with oral glucose tolerance test. In a multivariate regression analysis with adjustment for demographic and health covariates, higher chronic stress was related to higher fasting glucose (standardized regression coefficient: β = .09, p effect of stress through inflammation. Findings suggest that higher chronic stress is associated with poorer glucose regulation in Hispanics, prior to the onset of a clinical diabetes diagnosis.

  5. 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.

  6. Structure and assembly of group B streptococcus pilus 2b backbone protein.

    Science.gov (United States)

    Cozzi, Roberta; Malito, Enrico; Lazzarin, Maddalena; Nuccitelli, Annalisa; Castagnetti, Andrea; Bottomley, Matthew J; Margarit, Immaculada; Maione, Domenico; Rinaudo, C Daniela

    2015-01-01

    Group B Streptococcus (GBS) is a major cause of invasive disease in infants. Like other Gram-positive bacteria, GBS uses a sortase C-catalyzed transpeptidation mechanism to generate cell surface pili from backbone and ancillary pilin precursor substrates. The three pilus types identified in GBS contain structural subunits that are highly immunogenic and are promising candidates for the development of a broadly-protective vaccine. Here we report the X-ray crystal structure of the backbone protein of pilus 2b (BP-2b) at 1.06Å resolution. The structure reveals a classical IgG-like fold typical of the pilin subunits of other Gram-positive bacteria. The crystallized portion of the protein (residues 185-468) encompasses domains D2 and D3 that together confer high stability to the protein due to the presence of an internal isopeptide bond within each domain. The D2+D3 region, lacking the N-terminal D1 domain, was as potent as the entire protein in conferring protection against GBS challenge in a well-established mouse model. By site-directed mutagenesis and complementation studies in GBS knock-out strains we identified the residues and motives essential for assembly of the BP-2b monomers into high-molecular weight complexes, thus providing new insights into pilus 2b polymerization.

  7. Structure and assembly of group B streptococcus pilus 2b backbone protein.

    Directory of Open Access Journals (Sweden)

    Roberta Cozzi

    Full Text Available Group B Streptococcus (GBS is a major cause of invasive disease in infants. Like other Gram-positive bacteria, GBS uses a sortase C-catalyzed transpeptidation mechanism to generate cell surface pili from backbone and ancillary pilin precursor substrates. The three pilus types identified in GBS contain structural subunits that are highly immunogenic and are promising candidates for the development of a broadly-protective vaccine. Here we report the X-ray crystal structure of the backbone protein of pilus 2b (BP-2b at 1.06Å resolution. The structure reveals a classical IgG-like fold typical of the pilin subunits of other Gram-positive bacteria. The crystallized portion of the protein (residues 185-468 encompasses domains D2 and D3 that together confer high stability to the protein due to the presence of an internal isopeptide bond within each domain. The D2+D3 region, lacking the N-terminal D1 domain, was as potent as the entire protein in conferring protection against GBS challenge in a well-established mouse model. By site-directed mutagenesis and complementation studies in GBS knock-out strains we identified the residues and motives essential for assembly of the BP-2b monomers into high-molecular weight complexes, thus providing new insights into pilus 2b polymerization.

  8. D型打结器及其辅助机构的运动特性%Kinematic Characteristic Analysis of D-knotter and Its Ancillary Mechanisms

    Institute of Scientific and Technical Information of China (English)

    李双; 尹建军; 李耀明

    2011-01-01

    以苜邦9KF-8042型方草捆压捆机为研究对象,采用SOLIDWORKS建立D型打结器及其辅助机构的3D装配模型,导入ADAMS软件后对其动作过程进行运动学仿真,得到了捆扎打结过程各机构的运动学特性曲线,分析了各机构的运动特性,确定了机构各构件的耦合动作时序关系,可以为D型打结器及其辅助机构的工程反求和优化设计提供参考.%The Mubang 9KF-8042 baler for square straw bale was chosen as research object in this paper. 3D assemble model of D-knotter and its ancillary mechanisms was firstly buit up by using SOLIDWORKS software, and imported to ADAMS software for its kinematics simulation of enlacing and knotting process. The kinematic characteristic curves of D-knotter and its ancillary mechanisms were gained and analyzed during the process of enlacing and knotting.And then, coupling relationship of motion time series of each functional component was determined. It provides a reference for reverse engineering and optimization design of D-knotter and its ancillary mechanisms.

  9. NOAA Digital Orthophotography and Ancillary Oblique Imagery Collection for the Coasts of Main/New Hampshire, Massachusetts/Rhode Island/Connecticut, and Hudson River/Long Island /NY/NJ

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Project: NOAA Digital Orthophotography and Ancillary Oblique Imagery Collection for the Coasts of Main/New Hampshire, Massachusetts/Rhode Island/Connecticut, and...

  10. Phosphorylation of ATPase subunits of the 26S proteasome.

    Science.gov (United States)

    Mason, G G; Murray, R Z; Pappin, D; Rivett, A J

    1998-07-01

    The 26S proteasome complex plays a major role in the non-lysosomal degradation of intracellular proteins. Purified 26S proteasomes give a pattern of more than 40 spots on 2D-PAGE gels. The positions of subunits have been identified by mass spectrometry of tryptic peptides and by immunoblotting with subunit-specific antipeptide antibodies. Two-dimensional polyacrylamide gel electrophoresis of proteasomes immunoprecipitated from [32P]phosphate-labelled human embryo lung L-132 cells revealed the presence of at least three major phosphorylated polypeptides among the regulatory subunits as well as the C8 and C9 components of the core 20S proteasome. Comparison with the positions of the regulatory polypeptides revealed a minor phosphorylated form to be S7 (MSS1). Antibodies against S4, S6 (TBP7) and S12 (MOV34) all cross-reacted at the position of major phosphorylated polypeptides suggesting that several of the ATPase subunits may be phosphorylated. The phosphorylation of S4 was confirmed by double immunoprecipitation experiments in which 26S proteasomes were immunoprecipitated as above and dissociated and then S4 was immunoprecipitated with subunit-specific antibodies. Antibodies against the non-ATPase subunit S10, which has been suggested by others to be phosphorylated, did not coincide with the position of a phosphorylated polypeptide. Some differences were observed in the 2D-PAGE pattern of proteasomes immunoprecipitated from cultured cells compared to purified rat liver 26S proteasomes suggesting possible differences in subunit compositions of 26S proteasomes.

  11. Pituitary glycoprotein hormone a-subunit secretion by cirrhotic patients

    Directory of Open Access Journals (Sweden)

    Oliveira M.C.

    1999-01-01

    Full Text Available Secretion of the a-subunit of pituitary glycoprotein hormones usually follows the secretion of intact gonadotropins and is increased in gonadal failure and decreased in isolated gonadotropin deficiency. The aim of the present study was to determine the levels of the a-subunit in the serum of patients with cirrhosis of the liver and to compare the results obtained for eugonadal cirrhotic patients with those obtained for cirrhotic patients with hypogonadotropic hypogonadism. Forty-seven of 63 patients with cirrhosis (74.6% presented hypogonadism (which was central in 45 cases and primary in 2, 7 were eugonadal, and 9 women were in normal menopause. The serum a-subunit was measured by the fluorimetric method using monoclonal antibodies. Cross-reactivity with LH, TSH, FSH and hCG was 6.5, 1.2, 4.3 and 1.1%, respectively, with an intra-assay coefficient of variation (CV of less than 5% and an interassay CV of 5%, and sensitivity limit of 4 ng/l. The serum a-subunit concentration ranged from 36 to 6253 ng/l, with a median of 273 ng/l. The median was 251 ng/l for patients with central hypogonadism and 198 ng/l for eugonadal patients. The correlation between the a-subunit and basal LH levels was significant both in the total sample (r = 0.48, P<0.01 and in the cirrhotic patients with central hypogonadism (r = 0.33, P = 0.02. Among men with central hypogonadism there was a negative correlation between a-subunit levels and total testosterone levels (r = 0.54, P<0.01 as well as free testosterone levels (r = -0.53, P<0.01. In conclusion, although the a-subunit levels are correlated with LH levels, at present they cannot be used as markers for hypogonadism in patients with cirrhosis of the liver.

  12. NOX Activation by Subunit Interaction and Underlying Mechanisms in Disease

    Science.gov (United States)

    Rastogi, Radhika; Geng, Xiaokun; Li, Fengwu; Ding, Yuchuan

    2017-01-01

    Nicotinamide adenine dinucleotide phosphate (NAPDH) oxidase (NOX) is an enzyme complex with the sole function of producing superoxide anion and reactive oxygen species (ROS) at the expense of NADPH. Vital to the immune system as well as cellular signaling, NOX is also involved in the pathologies of a wide variety of disease states. Particularly, it is an integral player in many neurological diseases, including stroke, TBI, and neurodegenerative diseases. Pathologically, NOX produces an excessive amount of ROS that exceed the body’s antioxidant ability to neutralize them, leading to oxidative stress and aberrant signaling. This prevalence makes it an attractive therapeutic target and as such, NOX inhibitors have been studied and developed to counter NOX’s deleterious effects. However, recent studies of NOX have created a better understanding of the NOX complex. Comprised of independent cytosolic subunits, p47-phox, p67-phox, p40-phox and Rac, and membrane subunits, gp91-phox and p22-phox, the NOX complex requires a unique activation process through subunit interaction. Of these subunits, p47-phox plays the most important role in activation, binding and translocating the cytosolic subunits to the membrane and anchoring to p22-phox to organize the complex for NOX activation and function. Moreover, these interactions, particularly that between p47-phox and p22-phox, are dependent on phosphorylation initiated by upstream processes involving protein kinase C (PKC). This review will look at these interactions between subunits and with PKC. It will focus on the interaction involving p47-phox with p22-phox, key in bringing the cytosolic subunits to the membrane. Furthermore, the implication of these interactions as a target for NOX inhibitors such as apocynin will be discussed as a potential avenue for further investigation, in order to develop more specific NOX inhibitors based on the inhibition of NOX assembly and activation. PMID:28119569

  13. Routine use of ancillary investigations in staging diffuse large B-cell lymphoma improves the International Prognostic Index (IPI

    Directory of Open Access Journals (Sweden)

    Shadbolt Bruce

    2009-11-01

    Full Text Available Abstract Background The International Prognostic Index (IPI is used to determine prognosis in diffuse large B-cell lymphoma (DLBCL. One of the determinants of IPI is the stage of disease with bone marrow involvement being classified as stage IV. For the IPI, involvement on bone marrow is traditionally defined on the basis of histology with ancillary investigations used only in difficult cases to aid histological diagnosis. This study aimed to determine the effect of the routine use of flow cytometry, immunohistochemistry and molecular studies in bone marrow staging upon the IPI. Results Bone marrow trephines of 156 histologically proven DLBCL cases at initial diagnosis were assessed on routine histology, and immunohistochemistry using two T-cell markers (CD45RO and CD3, two B-cell markers (CD20 and CD79a and kappa and lambda light chains. Raw flow cytometry data on all samples were reanalysed and reinterpreted blindly. DNA extracted from archived paraffin-embedded trephine biopsy samples was used for immunoglobulin heavy chain and light chain gene rearrangement analysis. Using immunophenotyping (flow cytometry and immunohistochemistry, 30 (19.2% cases were upstaged to stage IV. A further 8 (5.1% cases were upstaged using molecular studies. A change in IPI was noted in 18 cases (11.5% on immunophenotyping alone, and 22 (14.1% cases on immunophenotyping and molecular testing. Comparison of two revised IPI models, 1 using immunophenotyping alone, and 2 using immunophenotyping with molecular studies, was performed with baseline IPI using a Cox regression model. It showed that the revised IPI model using immunophenotyping provides the best differentiation between the IPI categories. Conclusion Improved bone marrow staging using flow cytometry and immunohistochemistry improves the predictive value of the IPI in patients with DLBCL and should be performed routinely in all cases.

  14. Controllable Grid Interface for Testing Ancillary Service Controls and Fault Performance of Utility-Scale Wind Power Generation: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Gevorgian, Vahan; Koralewicz, Przemyslaw; Wallen, Robb; Muljadi, Eduard

    2017-02-01

    The rapid expansion of wind power has led many transmission system operators to demand modern wind power plants to comply with strict interconnection requirements. Such requirements involve various aspects of wind power plant operation, including fault ride-through and power quality performance as well as the provision of ancillary services to enhance grid reliability. During recent years, the National Renewable Energy Laboratory (NREL) of the U.S. Department of Energy has developed a new, groundbreaking testing apparatus and methodology to test and demonstrate many existing and future advanced controls for wind generation (and other renewable generation technologies) on the multimegawatt scale and medium-voltage levels. This paper describes the capabilities and control features of NREL's 7-MVA power electronic grid simulator (also called a controllable grid interface, or CGI) that enables testing many active and reactive power control features of modern wind turbine generators -- including inertial response, primary and secondary frequency responses, and voltage regulation -- under a controlled, medium-voltage grid environment. In particular, this paper focuses on the specifics of testing the balanced and unbalanced fault ride-through characteristics of wind turbine generators under simulated strong and weak medium-voltage grid conditions. In addition, this paper provides insights on the power hardware-in-the-loop feature implemented in the CGI to emulate (in real time) the conditions that might exist in various types of electric power systems under normal operations and/or contingency scenarios. Using actual test examples and simulation results, this paper describes the value of CGI as an ultimate modeling validation tool for all types of 'grid-friendly' controls by wind generation.

  15. 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.

  16. 鼠李糖乳杆菌菌毛SpaA亚基的表达、抗体制备及其种属特异性研究%Expression, antibody production and species specificity of SpaA pilin subunit from Lactobacillus rhamnosus

    Institute of Scientific and Technical Information of China (English)

    魏永峰; 杨振泉; 高璐; 饶胜其; 尹永祺; 方维明; 顾瑞霞

    2016-01-01

    [目的]制备鼠李糖乳杆菌菌毛亚基SpaA多克隆抗体,研究其种属特异性.[方法]应用PCR方法从鼠李糖乳杆菌GG的基因组扩增出spaA,并连接到质粒pET-28a(+)中.将重组质粒转化大肠杆菌BL21(DE3),经IPTG诱导表达和镍柱纯化制备重组SpaA.通过免疫BALB/c小鼠获得多克隆抗体,利用全菌ELISA、Western和Dot-blot分析了SpaA在18株乳酸菌(12个种)中的分布特征.[结果]表达的重组SpaA分子量为36kD,与预期大小一致;获得的SpaA抗体效价为1∶12 800. Western结果显示抗体与天然SpaA具有良好的反应性.在测定的18株乳酸菌中,鼠李糖乳杆菌、干酪乳杆菌、副干酪乳杆菌3个种属菌株的spaA基因PCR和RT-PCR检测均为阳性.但全菌ELISA和Dot-blot结果显示,只有3株鼠李糖乳杆菌的全菌细胞与SpaA抗体呈特异性反应,而其它种属的菌株没有明显的交叉反应.[结论]尽管spaA基因在鼠李糖乳杆菌、干酪乳杆菌、副干酪乳杆菌中具有高度同源性,但SpaA蛋白只特异性地呈现在鼠李糖乳杆菌细胞表面.本研究中获得的SpaA抗体,为高黏附性鼠李糖乳杆菌的免疫磁珠分离及菌毛功能研究提供了工具.

  17. 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...

  18. 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.

  19. Cholera Toxin B: One Subunit with Many Pharmaceutical Applications

    Directory of Open Access Journals (Sweden)

    Keegan J. Baldauf

    2015-03-01

    Full Text Available Cholera, a waterborne acute diarrheal disease caused by Vibrio cholerae, remains prevalent in underdeveloped countries and is a serious health threat to those living in unsanitary conditions. The major virulence factor is cholera toxin (CT, which consists of two subunits: the A subunit (CTA and the B subunit (CTB. CTB is a 55 kD homopentameric, non-toxic protein binding to the GM1 ganglioside on mammalian cells with high affinity. Currently, recombinantly produced CTB is used as a component of an internationally licensed oral cholera vaccine, as the protein induces potent humoral immunity that can neutralize CT in the gut. Additionally, recent studies have revealed that CTB administration leads to the induction of anti-inflammatory mechanisms in vivo. This review will cover the potential of CTB as an immunomodulatory and anti-inflammatory agent. We will also summarize various recombinant expression systems available for recombinant CTB bioproduction.

  20. Dengue vaccine: an update on recombinant subunit strategies.

    Science.gov (United States)

    Martin, J; Hermida, L

    2016-03-01

    Dengue is an increasing public health problem worldwide, with the four serotypes of the virus infecting over 390 million people annually. There is no specific treatment or antiviral drug for dengue, and prevention is largely limited to controlling the mosquito vectors or disrupting the human-vector contact. Despite the considerable progress made in recent years, an effective vaccine against the virus is not yet available. The development of a dengue vaccine has been hampered by many unique challenges, including the need to ensure the absence of vaccine-induced enhanced severity of disease. Recombinant protein subunit vaccines offer a safer alternative to other vaccine approaches. Several subunit vaccine candidates are presently under development, based on different structural and non-structural proteins of the virus. Novel adjuvants or immunopotentiating strategies are also being tested to improve their immunogenicity. This review summarizes the current status and development trends of subunit dengue vaccines.

  1. Proteasome activity and subunit composition in endometrial hyperplasia and cancer

    Directory of Open Access Journals (Sweden)

    L. V. Spirina

    2011-01-01

    Full Text Available In endometrial hyperplasia the total proteasome activity was not changed however the 26S proteasome activity was increased in comparison with the normal tissues. In endometrial cancer the high total proteasome activity and activities of 26S and 20S proteasomes wer e revealed. The changes in proteasome activities were correlated with the decreased content of α1α2α3α5α6α7 proteasome subunits and increased con- tents of LMP2, LMP7 and PA28β proteasome subunits compared to that in nonaltered tissues. Low content of α1α2α3α5α6α7 proteasome subunits was revealed at the second stage of cancer patients in comparison with that at the first stage.

  2. Cholera toxin B: one subunit with many pharmaceutical applications.

    Science.gov (United States)

    Baldauf, Keegan J; Royal, Joshua M; Hamorsky, Krystal Teasley; Matoba, Nobuyuki

    2015-03-20

    Cholera, a waterborne acute diarrheal disease caused by Vibrio cholerae, remains prevalent in underdeveloped countries and is a serious health threat to those living in unsanitary conditions. The major virulence factor is cholera toxin (CT), which consists of two subunits: the A subunit (CTA) and the B subunit (CTB). CTB is a 55 kD homopentameric, non-toxic protein binding to the GM1 ganglioside on mammalian cells with high affinity. Currently, recombinantly produced CTB is used as a component of an internationally licensed oral cholera vaccine, as the protein induces potent humoral immunity that can neutralize CT in the gut. Additionally, recent studies have revealed that CTB administration leads to the induction of anti-inflammatory mechanisms in vivo. This review will cover the potential of CTB as an immunomodulatory and anti-inflammatory agent. We will also summarize various recombinant expression systems available for recombinant CTB bioproduction.

  3. Antigenic breadth: a missing ingredient in HSV-2 subunit vaccines?

    Science.gov (United States)

    Halford, William P

    2014-06-01

    The successful human papillomavirus and hepatitis B virus subunit vaccines contain single viral proteins that represent 22 and 12%, respectively, of the antigens encoded by these tiny viruses. The herpes simplex virus 2 (HSV-2) genome is >20 times larger. Thus, a single protein subunit represents 1% of HSV-2's total antigenic breadth. Antigenic breadth may explain why HSV-2 glycoprotein subunit vaccines have failed in clinical trials, and why live HSV-2 vaccines that express 99% of HSV-2's proteome may be more effective. I review the mounting evidence that live HSV-2 vaccines offer a greater opportunity to stop the spread of genital herpes, and I consider the unfounded 'safety concerns' that have kept live HSV-2 vaccines out of U.S. clinical trials for 25 years.

  4. 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.

  5. Carrier subunit of plasma membrane transporter is required for oxidative folding of its helper subunit.

    Science.gov (United States)

    Rius, Mònica; Chillarón, Josep

    2012-05-25

    We study the amino acid transport system b(0,+) as a model for folding, assembly, and early traffic of membrane protein complexes. System b(0,+) is made of two disulfide-linked membrane subunits: the carrier, b(0,+) amino acid transporter (b(0,+)AT), a polytopic protein, and the helper, related to b(0,+) amino acid transporter (rBAT), a type II glycoprotein. rBAT ectodomain mutants display folding/trafficking defects that lead to type I cystinuria. Here we show that, in the presence of b(0,+)AT, three disulfides were formed in the rBAT ectodomain. Disulfides Cys-242-Cys-273 and Cys-571-Cys-666 were essential for biogenesis. Cys-673-Cys-685 was dispensable, but the single mutants C673S, and C685S showed compromised stability and trafficking. Cys-242-Cys-273 likely was the first disulfide to form, and unpaired Cys-242 or Cys-273 disrupted oxidative folding. Strikingly, unassembled rBAT was found as an ensemble of different redox species, mainly monomeric. The ensemble did not change upon inhibition of rBAT degradation. Overall, these results indicated a b(0,+)AT-dependent oxidative folding of the rBAT ectodomain, with the initial and probably cotranslational formation of Cys-242-Cys-273, followed by the oxidation of Cys-571-Cys-666 and Cys-673-Cys-685, that was completed posttranslationally.

  6. Efficient reconstitution of functional Escherichia coli 30S ribosomal subunits from a complete set of recombinant small subunit ribosomal proteins.

    Science.gov (United States)

    Culver, G M; Noller, H F

    1999-06-01

    Previous studies have shown that the 30S ribosomal subunit of Escherichia coli can be reconstituted in vitro from individually purified ribosomal proteins and 16S ribosomal RNA, which were isolated from natural 30S subunits. We have developed a 30S subunit reconstitution system that uses only recombinant ribosomal protein components. The genes encoding E. coli ribosomal proteins S2-S21 were cloned, and all twenty of the individual proteins were overexpressed and purified. Reconstitution, following standard procedures, using the complete set of recombinant proteins and purified 16S ribosomal RNA is highly inefficient. Efficient reconstitution of 30S subunits using these components requires sequential addition of proteins, following either the 30S subunit assembly map (Mizushima & Nomura, 1970, Nature 226:1214-1218; Held et al., 1974, J Biol Chem 249:3103-3111) or following the order of protein assembly predicted from in vitro assembly kinetics (Powers et al., 1993, J MoI Biol 232:362-374). In the first procedure, the proteins were divided into three groups, Group I (S4, S7, S8, S15, S17, and S20), Group II (S5, S6, S9, Sll, S12, S13, S16, S18, and S19), and Group III (S2, S3, S10, S14, and S21), which were sequentially added to 16S rRNA with a 20 min incubation at 42 degrees C following the addition of each group. In the second procedure, the proteins were divided into Group I (S4, S6, S11, S15, S16, S17, S18, and S20), Group II (S7, S8, S9, S13, and S19), Group II' (S5 and S12) and Group III (S2, S3, S10, S14, and S21). Similarly efficient reconstitution is observed whether the proteins are grouped according to the assembly map or according to the results of in vitro 30S subunit assembly kinetics. Although reconstitution of 30S subunits using the recombinant proteins is slightly less efficient than reconstitution using a mixture of total proteins isolated from 30S subunits, it is much more efficient than reconstitution using proteins that were individually isolated

  7. Assembly of tetra, di and mononuclear molecular cadmium phosphonates using 2,4,6-triisopropylphenylphosponic acid and ancillary ligands.

    Science.gov (United States)

    Chandrasekhar, Vadapalli; Sasikumar, Palani; Boomishankar, Ramamoorthy

    2008-10-14

    The reaction of ArPO(3)H(2) (Ar = 2,4,6-iPr(3)-C(6)H(2)) with Cd(CH(3)COO)(2).2H(2)O using various co-ligands such as methanol, dimethylformamide (DMF) and 3,5-dimethylpyrazole (DMPZH) resulted in the formation of tetranuclear assemblies [Cd(4)(ArPO(3))(2)(ArPO(3)H)(4)(CH(3)OH)(4)].3(CH(3)OH) (1), [Cd(4)(ArPO(3))(2)(ArPO(3)H)(4)(DMF)(4)].3(DMF) (2) and [Cd(4)(ArPO(3))(2)(ArPO(3)H)(4)(DMF)(2)(DMPZH)(2)].2(DMF).2(H(2)O) (3). In all of these compounds the tetranuclear cadmium array, containing two five-coordinate and two six-coordinate cadmium atoms, is held together by two mu(4) capping [ArPO(3)](2-) and four anisobidentate mu(2) [ArPO(2)(OH)](-) ligands. Each cadmium atom is bound to an additional ancillary ligand. The reaction of ArPO(3)H(2) with Cd(CH(3)COO)(2).2H(2)O in the presence of the chelating ligand 2,2'-bipyridine (bipy) leads to the exclusive formation of the dinuclear assembly [Cd(2)(ArPO(3)H)(4)(bipy)(2)].(CH(3)OH)(H(2)O) (4). The latter contains an eight-membered Cd(2)P(2)O(4) inorganic ring formed as a result of the bridging coordination action of two anisobidentate mu(2) [ArPO(2)(OH)](-) ligands. Each cadmium atom is bound by one chelating bipy and one monodentate [ArPO(2)(OH)](-) ligands. Use of four equivalents of 3,5-dimethylpyrazole leads to the formation of the mononuclear derivative [Cd(ArPO(3)H)(2)(DMPZH)(4)] (5). The molecular structure of the latter comprises of a central cadmium atom surrounded by six monodentate ligands. Four of these are neutral pyrazole ligands that occupy the equatorial plane; the remaining two are anionic phosphinate ligands which are present trans to each other. The thermal analysis of 1 and 4 reveals that the char residue obtained at 600 degrees C consists predominantly of Cd(2)P(2)O(7).

  8. Protein-disulfide Isomerase Displaces the Cholera Toxin A1 Subunit from the Holotoxin without Unfolding the A1 Subunit*

    OpenAIRE

    Taylor, Michael; Banerjee, Tuhina; Ray, Supriyo; Tatulian, Suren A.; Teter, Ken

    2011-01-01

    Protein-disulfide isomerase (PDI) has been proposed to exhibit an “unfoldase” activity against the catalytic A1 subunit of cholera toxin (CT). Unfolding of the CTA1 subunit is thought to displace it from the CT holotoxin and to prepare it for translocation to the cytosol. To date, the unfoldase activity of PDI has not been demonstrated for any substrate other than CTA1. An alternative explanation for the putative unfoldase activity of PDI has been suggested by recent structural studies demons...

  9. Compilation, quality control, analysis, and summary of discrete suspended-sediment and ancillary data in the United States, 1901-2010

    Science.gov (United States)

    Lee, Casey J.; Glysson, G. Douglas

    2013-01-01

    Human-induced and natural changes to the transport of sediment and sediment-associated constituents can degrade aquatic ecosystems and limit human uses of streams and rivers. The lack of a dedicated, easily accessible, quality-controlled database of sediment and ancillary data has made it difficult to identify sediment-related water-quality impairments and has limited understanding of how human actions affect suspended-sediment concentrations and transport. The purpose of this report is to describe the creation of a quality-controlled U.S. Geological Survey suspended-sediment database, provide guidance for its use, and summarize characteristics of suspended-sediment data through 2010. The database is provided as an online application at http://cida.usgs.gov/sediment to allow users to view, filter, and retrieve available suspended-sediment and ancillary data. A data recovery, filtration, and quality-control process was performed to expand the availability, representativeness, and utility of existing suspended-sediment data collected by the U.S. Geological Survey in the United States before January 1, 2011. Information on streamflow condition, sediment grain size, and upstream landscape condition were matched to sediment data and sediment-sampling sites to place data in context with factors that may influence sediment transport. Suspended-sediment and selected ancillary data are presented from across the United States with respect to time, streamflow, and landscape condition. Examples of potential uses of this database for identifying sediment-related impairments, assessing trends, and designing new data collection activities are provided. This report and database can support local and national-level decision making, project planning, and data mining activities related to the transport of suspended-sediment and sediment-associated constituents.

  10. Multi-Temporal Landsat Images and Ancillary Data for Land Use/Cover Change (LULCC Detection in the Southwest of Burkina Faso, West Africa

    Directory of Open Access Journals (Sweden)

    Benewinde J-B. Zoungrana

    2015-09-01

    Full Text Available Accurate quantification of land use/cover change (LULCC is important for efficient environmental management, especially in regions that are extremely affected by climate variability and continuous population growth such as West Africa. In this context, accurate LULC classification and statistically sound change area estimates are essential for a better understanding of LULCC processes. This study aimed at comparing mono-temporal and multi-temporal LULC classifications as well as their combination with ancillary data and to determine LULCC across the heterogeneous landscape of southwest Burkina Faso using accurate classification results. Landsat data (1999, 2006 and 2011 and ancillary data served as input features for the random forest classifier algorithm. Five LULC classes were identified: woodland, mixed vegetation, bare surface, water and agricultural area. A reference database was established using different sources including high-resolution images, aerial photo and field data. LULCC and LULC classification accuracies, area and area uncertainty were computed based on the method of adjusted error matrices. The results revealed that multi-temporal classification significantly outperformed those solely based on mono-temporal data in the study area. However, combining mono-temporal imagery and ancillary data for LULC classification had the same accuracy level as multi-temporal classification which is an indication that this combination is an efficient alternative to multi-temporal classification in the study region, where cloud free images are rare. The LULCC map obtained had an overall accuracy of 92%. Natural vegetation loss was estimated to be 17.9% ± 2.5% between 1999 and 2011. The study area experienced an increase in agricultural area and bare surface at the expense of woodland and mixed vegetation, which attests to the ongoing deforestation. These results can serve as means of regional and global land cover products validation, as they

  11. Evaluation system for regional ancillary service of power market%区域电力辅助服务市场评价体系

    Institute of Scientific and Technical Information of China (English)

    周旭; 顾洁; 程浩忠

    2011-01-01

    According to the achievement of evaluation research in the ancillary service of power market home and abroad, combined with the "two rules" issued by State Electricity Regulatory Commission of China (SERC), the evaluation index system for regional ancillary service of power market is built in this paper. It includes technical assessment, market conditions, market behavior, market performance, market risk, etc. The gray relative analysis evaluation model based on entropy weight is then established. Finally an example analysis results show that the model can objectively describe the importance degree of different indexes and then determine their weights, and comprehensively evaluate the market structure and operation of regional ancillary services, therefore to provide reference for healthy operation and scientific management.%结合中国电监会颁布的辅助服务的"两个细则"参考国内外对电力辅助服务市场的评价成果,从技术考核、市场条件、市场行为、市场表现以及市场风险等方面构建辅助服务市场评价指标体系,并建立基于熵权的灰色关联综合评价模型.算例分析表明:所建模型能够客观地描述不同指标的重要程度进而确定各指标的权重,从而对区域电力辅助服务市场的市场结构、运营情况等进行全面综合的比较和评价,为辅助服务市场的健康运营和科学管理提供参考.

  12. Peer-to-Peer Consultations: Ancillary Services Peer Exchange with India: Experience from South Africa, Europe & the United States (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2014-05-01

    In support of national and subnational decision makers, the 21st Century Power Partnership regularly works with country partners to organize peer-to-peer consultations on critical issues. In March 2014, 21CPP collaborated with the Regulatory Assistance Project - India to host two peer-to-peer exchanges among experts from India, South Africa, Europe, and the United States to discuss the provision of ancillary services, particularly in the context of added variability and uncertainty from renewable energy. This factsheet provides a high level summary of the peer-to-peer consultation.

  13. The role of charged residues in the transmembrane helices of monocarboxylate transporter 1 and its ancillary protein basigin in determining plasma membrane expression and catalytic activity

    OpenAIRE

    Manoharan, Christine; Wilson, Marieangela C.; Sessions, Richard B; Halestrap, Andrew P.

    2006-01-01

    Monocarboxylate transporters MCT1-MCT4 require basigin (CD147) or embigin (gp70), ancillary proteins with a glutamate residue in their single transmembrane (TM) domain, for plasma membrane (PM) expression and activity. Here we use site-directed mutagenesis and expression in COS cells or Xenopus oocytes to investigate whether this glutamate (Glu218 in basigin) may charge-pair with a positively charged TM-residue of MCT1. Such residues were predicted using a new molecular model of MCT1 based up...

  14. Analysis of the subunit stoichiometries in viral entry.

    Directory of Open Access Journals (Sweden)

    Carsten Magnus

    Full Text Available Virions of the Human Immunodeficiency Virus (HIV infect cells by first attaching with their surface spikes to the CD4 receptor on target cells. This leads to conformational changes in the viral spikes, enabling the virus to engage a coreceptor, commonly CCR5 or CXCR4, and consecutively to insert the fusion peptide into the cellular membrane. Finally, the viral and the cellular membranes fuse. The HIV spike is a trimer consisting of three identical heterodimers composed of the gp120 and gp41 envelope proteins. Each of the gp120 proteins in the trimer is capable of attaching to the CD4 receptor and the coreceptor, and each of the three gp41 units harbors a fusion domain. It is still under debate how many of the envelope subunits within a given trimer have to bind to the CD4 receptors and to the coreceptors, and how many gp41 protein fusion domains are required for fusion. These numbers are referred to as subunit stoichiometries. We present a mathematical framework for estimating these parameters individually by analyzing infectivity assays with pseudotyped viruses. We find that the number of spikes that are engaged in mediating cell entry and the distribution of the spike number play important roles for the estimation of the subunit stoichiometries. Our model framework also shows why it is important to subdivide the question of the number of functional subunits within one trimer into the three different subunit stoichiometries. In a second step, we extend our models to study whether the subunits within one trimer cooperate during receptor binding and fusion. As an example for how our models can be applied, we reanalyze a data set on subunit stoichiometries. We find that two envelope proteins have to engage with CD4-receptors and coreceptors and that two fusion proteins must be revealed within one trimer for viral entry. Our study is motivated by the mechanism of HIV entry but the experimental technique and the model framework can be extended to

  15. Synthesis and Opto-electronic Properties of a Red-Emitting Heteroleptic Platinum Complex Using Pyrazol-based Diketone Derivative as Ancillary Ligand%Synthesis and Opto-electronic Properties of a Red-Emitting Heteroleptic Platinum Complex Using Pyrazol-based Diketone Derivative as Ancillary Ligand

    Institute of Scientific and Technical Information of China (English)

    邓继勇; 王亚飞; 李小双; 倪美君; 刘明; 刘煜; 雷钢铁; 朱美香; 朱卫国

    2011-01-01

    A red-emitting heteroleptic cyclometalated platinum(II) complex containing an ancillary ligand of pyra- zol-based diketone derivative was synthesized. Its optophysical and electroluminescent properties were studied. Compared to the reported (piq)Pt(acac) complex, this platinum(II) complex exhibited a blue-shifted UV absorption band at 300--450 nm, a low LUMO energy level and improved electroluminescent property. Using this platinum(II) complex as a single doping emitter and a blend of ploy(9,9-dioctylfluorene) and 2-tert-butylphenyl-5-phenyl- 1,3,4-oxadiazole as a host matrix, the fabricated polymer light-emitting devices displayed saturated red emission with a peak at 648 um and a shoulder at 601 nm. Furthermore, the emission quenching of the platinum(II) complex was significantly suppressed in these devices at high current density due to an introduction of the non-planar pyra- zol group into the ancillary ligand.

  16. Effect of high and low molecular weight glutenin subunits, and subunits of gliadin on physicochemical parameters of different wheat genotypes

    Directory of Open Access Journals (Sweden)

    Mariana Souza Costa

    2013-02-01

    Full Text Available Identification of functional properties of wheat flour by specific tests allows genotypes with appropriate characteristics to be selected for specific industrial uses. The objective of wheat breeding programs is to improve the quality of germplasm bank in order to be able to develop wheat with suitable gluten strength and extensibility for bread making. The aim of this study was to evaluate 16 wheat genotypes by correlating both glutenin subunits of high and low molecular weight and gliadin subunits with the physicochemical characteristics of the grain. Protein content, sedimentation volume, sedimentation index, and falling number values were analyzed after the grains were milled. Hectoliter weight and mass of 1000 seeds were also determined. The glutenin and gliadin subunits were separated using polyacrylamide gel in the presence of sodium dodecyl sulfate. The data were evaluated using variance analysis, Pearson's correlation, principal component analysis, and cluster analysis. The IPR 85, IPR Catuara TM, T 091015, and T 091069 genotypes stood out from the others, which indicate their possibly superior grain quality with higher sedimentation volume, higher sedimentation index, and higher mass of 1000 seeds; these genotypes possessed the subunits 1 (Glu-A1, 5 + 10 (Glu-D1, c (Glu-A3, and b (Glu-B3, with exception of T 091069 genotype that possessed the g allele instead of b in the Glu-B3.

  17. 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.

  18. Integrated snow and avalanche monitoring syatem for Indian Himalaya using multi-temporal satellite imagery and ancillary data

    Science.gov (United States)

    Sharma, S. S.; Mani, Sneh; Mathur, P.

    . Different methods have been used for the analysis of the temporal changes in satellite images. Multi-sensor data fusion techniques have been applied to increase the accuracy of classification, and also for extraction of necessary information about characteristics of snow and avalanches and the ground conditions. The results of the analysis of time series of last two winters are reported. The study confirms that significant changes in snow characteristics and wetness are mainly due to large variations in temperature at these altitudes, which contribute towards avalanche activities in early winter. A definite relationship has been observed between snow wetness, altitude and period of the year with respect to the probability of an avalanche occurrence. Snow wetness is found to be inversely proportional to the altitude, whereas probability of an avalanche is directly proportional to the wetness of snow, lying either over thin grass or boulder-covered ground. The results were verified through extensive field measurements. The emphasis has been laid on establishment of a dense network of Automatic Weather Stations (AWS), Upper Air Stations (UAS) and observatories in entire Himalaya; development of GIS based data bases using satellite imageries and other ancillary data for weather, snow and land cover monitoring. Records of past years will provide base information for realistic estimation of the impact of climatic changes and confidence to predict the weather and avalanches in various regions of Himalaya. Key Words: Integrated Monitoring System, Time series multi-sensor/multi-temporal Satellite Imageries, Multi-sensor Data Fusion, Change Detection, Snow characteristics

  19. Integrated snow and avalanche monitoring system for Indian Himalaya using multi-temporal satellite imagery and ancillary data

    Science.gov (United States)

    Sharma, S. S.; Mani, Sneh; Mathur, P.

    . Different methods have been used for the analysis of the temporal changes in satellite images. Multi-sensor data fusion techniques have been applied to increase the accuracy of classification, and also for extraction of necessary information about characteristics of snow and avalanches and the ground conditions. The results of the analysis of time series of last two winters are reported. The study confirms that significant changes in snow characteristics and wetness are mainly due to large variations in temperature at these altitudes, which contribute towards avalanche activities in early winter. A definite relationship has been observed between snow wetness, altitude and period of the year with respect to the probability of an avalanche occurrence. Snow wetness is found to be inversely proportional to the altitude, whereas probability of an avalanche is directly proportional to the wetness of snow, lying either over thin grass or boulder-covered ground. The results were verified through extensive field measurements. The emphasis has been laid on establishment of a dense network of Automatic Weather Stations (AWS), Upper Air Stations (UAS) and observatories in entire Himalaya; development of GIS based data bases using satellite imageries and other ancillary data for weather, snow and land cover monitoring. Records of past years will provide base information for realistic estimation of the impact of climatic changes and confidence to predict the weather and avalanches in various regions of Himalaya. Key Words: Integrated Monitoring System, Time series multi-sensor/multi-temporal Satellite Imageries, Multi-sensor Data Fusion, Change Detection, Snow characteristics

  20. Synthesis, Characterization, Properties and DFT Calculations of 2-(Benzo[b]thiophen-2-yl)pyridine-based Iridium(III) Complexes with Different Ancillary Ligands.

    Science.gov (United States)

    Li, Gao-Nan; Zeng, Yong-Pi; Li, Kai-Xiu; Chen, Hao-Hua; Xie, Hui; Zhang, Fu-Lin; Chen, Guang-Ying; Niu, Zhi-Gang

    2016-01-01

    A series of new cyclometalated btp-based iridium(III) complexes with three different ancillary ligands, Ir(btp)2(bozp) (3a), Ir(btp)2(btzp) (3b) and Ir(btp)2(izp) (3c) (btp = 2-(benzo[b]thiophen-2-yl)pyridine, bozp =2-(benzo[d]oxazol-2-yl)phenol, btzp =2-(benzo[d]thiazol-2-yl)phenol, izp = 2-(2 H-indazol-2-yl)phenol), have been synthesized and fully characterized. The crystal structure of 3b has been determined by single crystal X-ray diffraction analysis. A comparative study has been carried out for complexes 3a - 3c by UV-vis absorption spectroscopy, photoluminescence spectroscopy, cyclic voltammetry and DFT calculations. This observation illustrates that the substitution of N or S in ancillary ligand can lead to a marked bathochromic shift of absorption and emission wavelengths. The spectroscopic characterisation of these complexes has been complemented by DFT and TD-DFT calculations, supporting the assignment of (3)MLCT/(3)LC to the lowest energy excited state.

  1. Vehicle Ancillary Load Reduction Project Close-Out Report: An Overview of the Task and a Compilation of the Research Results

    Energy Technology Data Exchange (ETDEWEB)

    Rugh, J.; Farrington, R.

    2008-01-01

    The amount of fuel used for climate control in U.S. vehicles reduces the fuel economy of more than 200 million light-duty conventional vehicles and thus affects U.S. energy security. Researchers at the DOE National Renewable Energy Laboratory estimated that the United States consumes about 7 billion gallons of fuel per year for air-conditioning (A/C) light-duty vehicles. Using a variety of tools, NREL researchers developed innovative techniques and technologies to reduce the amount of fuel needed for these vehicles' ancillary loads. For example, they found that the A/C cooling capacity of 5.7 kW in a Cadillac STS could be reduced by 30% while maintaining a cooldown performance of 30 minutes. A simulation showed that reducing the A/C load by 30% decreased A/C fuel consumption by 26%. Other simulations supported the great potential for improving fuel economy by using new technologies and techniques developed to reduce ancillary loads.

  2. Testing experimental subunit furunculosis vaccines for rainbow trout

    DEFF Research Database (Denmark)

    Marana, Moonika H.; Chettri, Jiwan Kumar; Skov, Jakob;

    2016-01-01

    Aeromonas salmonicida subsp. salmonicida (AS) is the etiological agent of typical furunculosis in salmonid fish. The disease causes bacterial septicemia and is a major fish health problem in salmonid aquaculture worldwide, inducing high morbidity and mortality. In this study we vaccinated rainbow...... trout with subunit vaccines containing protein antigens that were selected based on an in silico antigen discovery approach. Thus, the proteome of AS strain A449 was analyzed by an antigen discovery platform and its proteins consequently ranked by their predicted ability to evoke protective immune...... response against AS. Fourteen proteins were prepared in 3 different experimental subunit vaccine combinations and used to vaccinate rainbow trout by intraperitoneal (i.p.) injection. We tested the proteins for their ability to elicit antibody production and protection. Thus, fish were exposed to virulent...

  3. Developments of Subunit and VLP Vaccines Against Influenza A Virus

    Institute of Scientific and Technical Information of China (English)

    Ma-ping Deng; Zhi-hong Hu; Hua-lin Wang; Fei Deng

    2012-01-01

    Influenza virus is a continuous and severe global threat to mankind.The continuously re-emerging disease gives rise to thousands of deaths and enormous economic losses each year,which emphasizes the urgency and necessity to develop high-quality influenza vaccines in a safer,more efficient and economic way.The influenza subunit and VLP vaccines,taking the advantage of recombinant DNA technologies and expression system platforms,can be produced in such an ideal way.This review summarized the recent advancements in the research and development of influenza subunit and VLP vaccines based on the recombinant expression of hemagglutinin antigen (HA),neuraminidase antigen (NA),Matrix 2 protein (M2) and nucleocapsid protein (NP).It would help to get insight into the current stage of influenza vaccines,and suggest the future design and development of novel influenza vaccines.

  4. Thermostable Subunit Vaccines for Pulmonary Delivery: How Close Are We?

    DEFF Research Database (Denmark)

    Foged, Camilla

    2016-01-01

    , such as influenza, tuberculosis, and Ebola, for which no good universal vaccines exist. At least two pharmaceutical improvements are expected to help filling this gap: i) The development of thermostable vaccine dosage forms, and ii) the full exploitation of the adjuvant technology for subunit vaccines to potentiate......In the past century, vaccines have contributed to a significant improvement in global public health by preventing a number of infectious diseases. Despite this, the vaccine field is still facing challenges related to incomplete vaccine coverage and persistent difficult vaccine targets...... strong immune responses. This review highlights the status and recent advances in formulation and pulmonary delivery of thermostable human subunit vaccines. Such vaccines are very appealing from compliance, distribution and immunological point of view: Being non-invasive, inhalable vaccines are self...

  5. Mapping of the Mouse Actin Capping Protein Beta Subunit Gene

    Directory of Open Access Journals (Sweden)

    Cooper John A

    2000-07-01

    Full Text Available Abstract Background Capping protein (CP, a heterodimer of α and β subunits, is found in all eukaryotes. CP binds to the barbed ends of actin filaments in vitro and controls actin assembly and cell motility in vivo. Vertebrates have three isoforms of CPβ produced by alternatively splicing from one gene; lower organisms have one gene and one isoform. Results We isolated genomic clones corresponding to the β subunit of mouse CP and identified its chromosomal location by interspecies backcross mapping. Conclusions The CPβ gene (Cappb1 mapped to Chromosome 4 between Cdc42 and D4Mit312. Three mouse mutations, snubnose, curly tail, and cribriform degeneration, map in the vicinity of the β gene.

  6. 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

  7. The European database on small subunit ribosomal RNA

    OpenAIRE

    Wuyts, Jan; Van de Peer, Yves; Winkelmans, Tina; De Wachter, Rupert

    2002-01-01

    The European database on SSU rRNA can be consulted via the World WideWeb at http://rrna.uia.ac.be/ssu/ and compiles all complete or nearly complete small subunit ribosomal RNA sequences. Sequences are provided in aligned format. The alignment takes into account the secondary structure information derived by comparative sequence analysis of thousands of sequences. Additional information such as literature references, taxonomy, secondary structure models and nucleotide variability maps, is also...

  8. Structure of the archaeal Cascade subunit Csa5

    Science.gov (United States)

    Reeks, Judith; Graham, Shirley; Anderson, Linzi; Liu, Huanting; White, Malcolm F.; Naismith, James H.

    2013-01-01

    The Cascade complex for CRISPR-mediated antiviral immunity uses CRISPR RNA (crRNA) to target invading DNA species from mobile elements such as viruses, leading to their destruction. The core of the Cascade effector complex consists of the Cas5 and Cas7 subunits, which are widely conserved in prokaryotes. Cas7 binds crRNA and forms the helical backbone of Cascade. Many archaea encode a version of the Cascade complex (denoted Type I-A) that includes a Csa5 (or small) subunit, which interacts weakly with the core proteins. Here, we report the crystal structure of the Csa5 protein from Sulfolobus solfataricus. Csa5 comprises a conserved α-helical domain with a small insertion consisting of a weakly conserved β-strand domain. In the crystal, the Csa5 monomers have multimerized into infinite helical threads. At each interface is a strictly conserved intersubunit salt bridge, deletion of which disrupts multimerization. Structural analysis indicates a shared evolutionary history among the small subunits of the CRISPR effector complexes. The same α-helical domain is found in the C-terminal domain of Cse2 (from Type I-E Cascade), while the N-terminal domain of Cse2 is found in Cmr5 of the CMR (Type III-B) effector complex. As Cmr5 shares no match with Csa5, two possibilities present themselves: selective domain loss from an ancestral Cse2 to create two new subfamilies or domain fusion of two separate families to create a new Cse2 family. A definitive answer awaits structural studies of further small subunits from other CRISPR effector complexes. PMID:23846216

  9. Immunological Effect of Subunit Influenza Vaccine Entrapped by Liposomes

    Institute of Scientific and Technical Information of China (English)

    SHUI-HUA ZHANG; JIA-XU LIANG; SHU-YAN DAI; XIAO-LIN QIU; YAN-RONG YI; YUN PAN

    2009-01-01

    Objective To elevate the immunological effect of subunit influenza vaccine in infants and aged people (over 60) using liposomal adjuvant in the context of its relatively low immunity and to investigate the relation between vaccine antigens and liposomal characteristics. Methods Several formulations of liposomal subunit influenza vaccine were prepared. Their relevant characteristics were investigated to optimize the preparation method. Antisera obtained from immunizinged mice were used to evaluate the antibody titers of various samples by HI and ELISA. Results Liposomal trivalent influenza vaccine prepared by film evaporation in combinedation with freeze-drying significantly increased its immunological effect in SPF Balb/c mice. Liposomal vaccine stimulated the antibody titer of H3N2, H1N1, and B much stronger than conventional influenza vaccine. As a result, liposomal vaccine (mean size: 4.5-5.5 μm, entrapment efficiency: 30%-40%) significantly increased the immunological effect of subunit influenza vaccine. Conclusion The immune effect of liposomal vaccine depends on different antigens, and enhanced immunity is not positively correlated with the mean size of liposome or its entrapped efficiency.

  10. Ribosomal small subunit domains radiate from a central core

    Science.gov (United States)

    Gulen, Burak; Petrov, Anton S.; Okafor, C. Denise; Vander Wood, Drew; O'Neill, Eric B.; Hud, Nicholas V.; Williams, Loren Dean

    2016-02-01

    The domain architecture of a large RNA can help explain and/or predict folding, function, biogenesis and evolution. We offer a formal and general definition of an RNA domain and use that definition to experimentally characterize the rRNA of the ribosomal small subunit. Here the rRNA comprising a domain is compact, with a self-contained system of molecular interactions. A given rRNA helix or stem-loop must be allocated uniquely to a single domain. Local changes such as mutations can give domain-wide effects. Helices within a domain have interdependent orientations, stabilities and interactions. With these criteria we identify a core domain (domain A) of small subunit rRNA. Domain A acts as a hub, linking the four peripheral domains and imposing orientational and positional restraints on the other domains. Experimental characterization of isolated domain A, and mutations and truncations of it, by methods including selective 2‧OH acylation analyzed by primer extension and circular dichroism spectroscopy are consistent with our architectural model. The results support the utility of the concept of an RNA domain. Domain A, which exhibits structural similarity to tRNA, appears to be an essential core of the small ribosomal subunit.

  11. Ribosomal small subunit domains radiate from a central core

    Science.gov (United States)

    Gulen, Burak; Petrov, Anton S.; Okafor, C. Denise; Vander Wood, Drew; O’Neill, Eric B.; Hud, Nicholas V.; Williams, Loren Dean

    2016-01-01

    The domain architecture of a large RNA can help explain and/or predict folding, function, biogenesis and evolution. We offer a formal and general definition of an RNA domain and use that definition to experimentally characterize the rRNA of the ribosomal small subunit. Here the rRNA comprising a domain is compact, with a self-contained system of molecular interactions. A given rRNA helix or stem-loop must be allocated uniquely to a single domain. Local changes such as mutations can give domain-wide effects. Helices within a domain have interdependent orientations, stabilities and interactions. With these criteria we identify a core domain (domain A) of small subunit rRNA. Domain A acts as a hub, linking the four peripheral domains and imposing orientational and positional restraints on the other domains. Experimental characterization of isolated domain A, and mutations and truncations of it, by methods including selective 2′OH acylation analyzed by primer extension and circular dichroism spectroscopy are consistent with our architectural model. The results support the utility of the concept of an RNA domain. Domain A, which exhibits structural similarity to tRNA, appears to be an essential core of the small ribosomal subunit. PMID:26876483

  12. Function and Subunit Interactions of the N-terminal Domain of Subunit a (Vph1p) of the Yeast V-ATPase*

    OpenAIRE

    Qi, Jie; Forgac, Michael

    2008-01-01

    The vacuolar (H+)-ATPases (V-ATPases) are ATP-dependent proton pumps that operate by a rotary mechanism in which ATP hydrolysis drives rotation of a ring of proteolipid subunits relative to subunit a within the integral V0 domain. In vivo dissociation of the V-ATPase (an important regulatory mechanism) generates a V0 domain that does not passively conduct protons. EM analysis indicates that the N-terminal domain of subunit a approaches the rotary subunits in free V0, ...

  13. Electronic Structures and Spectroscopic Properties of a Novel Iridium (Ⅲ) Complex with an Ancillary Ligand 2- (4-Trifluoromethyl -2-Hydroxylphenyl)Benzothiazole

    Institute of Scientific and Technical Information of China (English)

    LEI Li-Ping; HAO Yu-Ying; FAN Wen-Hao; XU Sing-She

    2011-01-01

    Iridium (W) complexes with 2-phenylpyridine (ppy) have been demonstrated as a type of promising phosphorescence dopant in emitting layers of organic light emitting diodes (OLKDs). In most iridium (M) complexes, there exist the strong spin-orbit coupling between it-orbiteds of cyclometalated ligands and 5d orbitals of the centric iridium. We study a novel iridium (M) complex (ppy)2lr(4-TfmBTZ) with ppy as cyclometalated ligands and 2-(4-trifluoromcthyl-2-hydroxyIphenyl)benzothiazole (4-TfmBTZ) as an ancillary ligand using the Gaussian 03 program. The geometries, electronic structures and spectroscopic properties of this iridium (M) complex are investigated by density functional theory (DFT) and time-dependent density functional theory (TD-DFT). The results show that the spin-orbit coupling occurs not only between ppy and iridium atom but also between 4-TfmBTZ and iridium atom in this complex. The highest occupied molecular orbital is dominantly localized on the Ir atom and 4-TfmBTZ ligand, while the lowest unoccupied molecular orbital on 4-TfmBTZ ligand. The triplet lowest-lying transition is attributed to the Ir-to-4-TfmBTZ charge-transfer ^MLCT) transition while the sub-low-lying transitions are assigned to the AMLCT transitions oflr(ppy)I. The nature of the lowest unoccupied orbital changes from ppy-localizcd to 4-TfmBTZ-locaIized and reveals that phosphorescent color oflr(M) complex can be controlled by the ancillary ligand and substitucnt.%@@ Iridium (Ⅲ) complexes with 2-phenylpyridine (ppy) have been demonstrated as a type of promising phospho- rescence dopant in emitting layers of organic light emitting diodes (OLEI)s).In most iridium (Ⅲ) complexes, there exist the strong spin-orbit coupling between π-orbitals of cyclometalated ligands anti 5d orbitals of the ccntric iridium.We study a novel iridium (Ⅲ) complex (ppy)2Ir(4-TfmBTZ) with ppy as cyclometalated ligands and 2-(4-trifluoromethyl-2-hydroxylphenyl)benzothiazole (4-TfmBTZ) as an ancillary ligand

  14. 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.

  15. 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.

  16. 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...

  17. Associations of Structural and Functional Social Support with Diabetes Prevalence in U.S. Hispanics/Latinos: Results from the HCHS/SOL Sociocultural Ancillary Study

    Science.gov (United States)

    Gallo, Linda C.; Fortmann, Addie L.; McCurley, Jessica L.; Isasi, Carmen R.; Penedo, Frank J.; Daviglus, Martha L.; Roesch, Scott C.; Talavera, Gregory A.; Gouskova, Natalia; Gonzalez, Franklyn; Schneiderman, Neil; Carnethon, Mercedes R.

    2015-01-01

    Background Little research has examined associations of social support with diabetes (or other physical health outcomes) in Hispanics, who are at elevated risk. Purpose We examined associations between social support and diabetes prevalence in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) Sociocultural Ancillary Study. Methods Participants were 5181 adults, 18–74 years old, representing diverse Hispanic backgrounds, who underwent baseline exam with fasting blood draw, oral glucose tolerance test, medication review, sociodemographic assessment, and sociocultural exam with functional and structural social support measures. Results In adjusted analyses, one standard deviation higher structural and functional social support related to 16% and 15% lower odds, respectively, of having diabetes. Structural and functional support were related to both previously diagnosed diabetes (OR = .84 and .88, respectively) and newly recognized diabetes prevalence (OR = .84 and .83, respectively). Conclusions Higher functional and structural social support are associated with lower diabetes prevalence in Hispanics/Latinos. PMID:25107504

  18. CHRISGAS Project. WP13: Ancillary and Novel Processes. Final Report: Separation of Hydrogen with Membranes Combined with Water Gas Shift Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Hervas, J. M.; Marono, M.; Barreiro, M. M.

    2011-05-13

    Oxygen pressurized gasification of biomass out stands as a very promising approach to obtain energy or hydrogen from renewable sources. The technical feasibility of this technology has been investigated under the scope of the VI FP CHRISGAS project, which started in September 2004 and had a duration of five and a half years. The Division of Combustion and Gasification of CIEMAT participated in this project in Work Package 13: Ancillary and novel processes, studying innovative gas separation and gas upgrading systems. Such systems include novel or available high temperature water gas shift catalysts and commercially available membranes not yet tried in this type of atmosphere. This report describes the activities carried out during the project regarding the performance of high temperature water gas shift catalysts for upgrading of synthesis gas obtained from biomass gasification, the separation of H2 with selective membranes and the combination of both processes in one by means of a catalytic membrane reactor. (Author) 20 refs.

  19. The right to arrange ancillary services in line with municipal awards of concession; Das Recht auf Vereinbarung von Nebenleistungen im Rahmen gemeindlicher Konzessionsvergaben

    Energy Technology Data Exchange (ETDEWEB)

    Templin, Wolf [Boos Hummel und Wegerich Rechtsanwaelte, Berlin (Germany)

    2012-12-15

    Due to the plurality of concession contracts currently levelling off in the fields of electricity and natural gas as well as due to the increasing competition for the power distribution systems, the municipal granting of concession contracts as well as the relevant standards come in the focus of the legal disputes. Recently, the increasing competition and the claims of sustainable impacts of the municipalities on the local energy policy also in line with the awarding of concessions have led to the use of concession contracts for the control of local government concerns and climate political concerns of the municipalities. Under this aspect, the author of the contribution under consideration report on the right to arrange ancillary services in line with municipal awards of concession.

  20. Electronic Structures and Spectroscopic Properties of a Novel Iridium (III) Complex with an Ancillary Ligand 2-(4-Trifluoromethyl -2-Hydroxylphenyl) Benzothiazole

    Science.gov (United States)

    Lei, Li-Ping; Hao, Yu-Ying; Fan, Wen-Hao; Xu, Bing-She

    2011-06-01

    Iridium (III) complexes with 2-phenylpyridine (ppy) have been demonstrated as a type of promising phosphorescence dopant in emitting layers of organic light emitting diodes (OLEDs). In most iridium (III) complexes, there exist the strong spin-orbit coupling between π-orbitals of cyclometalated ligands and 5d orbitals of the centric iridium. We study a novel iridium (III) complex (ppy)2Ir(4-TfmBTZ) with ppy as cyclometalated ligands and 2-(4-trifluoromethyl-2-hydroxylphenyl)benzothiazole (4-TfmBTZ) as an ancillary ligand using the Gaussian 03 program. The geometries, electronic structures and spectroscopic properties of this iridium (III) complex are investigated by density functional theory (DFT) and time-dependent density functional theory (TD-DFT). The results show that the spin-orbit coupling occurs not only between ppy and iridium atom but also between 4-TfmBTZ and iridium atom in this complex. The highest occupied molecular orbital is dominantly localized on the Ir atom and 4-TfmBTZ ligand, while the lowest unoccupied molecular orbital on 4-TfmBTZ ligand. The triplet lowest-lying transition is attributed to the Ir-to-4-TfmBTZ charge-transfer (3MLCT) transition while the sub-low-lying transitions are assigned to the 3MLCT transitions of Ir(ppy)2. The nature of the lowest unoccupied orbital changes from ppy-localized to 4-TfmBTZ-localized and reveals that phosphorescent color of Ir(III) complex can be controlled by the ancillary ligand and substituent.

  1. Human mediator subunit MED15 promotes transcriptional activation.

    Science.gov (United States)

    Nakatsubo, Takuya; Nishitani, Saori; Kikuchi, Yuko; Iida, Satoshi; Yamada, Kana; Tanaka, Aki; Ohkuma, Yoshiaki

    2014-10-01

    In eukaryotes, the Mediator complex is an essential transcriptional cofactor of RNA polymerase II (Pol II). In humans, it contains up to 30 subunits and consists of four modules: head, middle, tail, and CDK/Cyclin. One of the subunits, MED15, is located in the tail module, and was initially identified as Gal11 in budding yeast, where it plays an essential role in the transcriptional regulation of galactose metabolism with the potent transcriptional activator Gal4. For this reason, we investigated the function of the human MED15 subunit (hMED15) in transcriptional activation. First, we measured the effect of hMED15 knockdown on cell growth in HeLa cells. The growth rate was greatly reduced. By immunostaining, we observed the colocalization of hMED15 with the general transcription factors TFIIE and TFIIH in the nucleus. We measured the effects of siRNA-mediated knockdown of hMED15 on transcriptional activation using two different transcriptional activators, VP16 and SREBP1a. Treatment with siRNAs reduced transcriptional activation, and this reduction could be rescued by overexpression of HA/Flag-tagged, wild-type hMED15. To investigate hMED15 localization, we treated human MCF-7 cells with the MDM2 inhibitor Nutlin-3, thus inducing p21 transcription. We found that hMED15 localized to both the p53 binding site and the p21 promoter region, along with TFIIE and TFIIH. These results indicate that hMED15 promotes transcriptional activation.

  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. 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.

  4. Effects of metal ions on recombinant calcineurin A subunit

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Effects of metal ions on activities and solution conformations of calcineurin A subunit have been examined.The ability of several metal ions to activate calcineurin A has been tested with Ni2+>Mn2+>Mg2+/Ca2+.The corresponding CD spectra and intrinsic fluorescent emission spectra show that calcineurin A exists in different metal ion-dependent conformation states.Effects of the different concentritions of Ni2+ on activities and solution conformations of calcineurin A have been tested too.Results indicate that effects of these metal ions to activate calcineurin are due to their conformational changes.

  5. The phosphorylation pattern of bovine heart complex I subunits

    DEFF Research Database (Denmark)

    Palmisano, Giuseppe; Sardanelli, Anna Maria; Signorile, Anna;

    2007-01-01

    The phosphoproteome of bovine heart complex I of the respiratory chain has been analysed with a procedure based on nondenaturing gel electrophoretic separation of complex I from small quantities of mitochondria samples, in-gel digestion, in combination with phosphopeptide enrichment by titanium...... dioxide and MS. The results, complemented by analyses of purified samples of complex I, showed phosphorylation of five subunits of the complex, 42 kDa (human gene NDUFA10), ESSS, B14.5a (human gene NDUFA7), B14.5b (human gene NDUFC2) and B16.6 (GRIM-19). MS also revealed the presence of phosphorylated...

  6. Sortase A substrate specificity in GBS pilus 2a cell wall anchoring.

    Science.gov (United States)

    Necchi, Francesca; Nardi-Dei, Vincenzo; Biagini, Massimiliano; Assfalg, Michael; Nuccitelli, Annalisa; Cozzi, Roberta; Norais, Nathalie; Telford, John L; Rinaudo, C Daniela; Grandi, Guido; Maione, Domenico

    2011-01-01

    Streptococcus agalactiae, also referred to as Group B Streptococcus (GBS), is one of the most common causes of life-threatening bacterial infections in infants. In recent years cell surface pili have been identified in several Gram-positive bacteria, including GBS, as important virulence factors and promising vaccine candidates. In GBS, three structurally distinct types of pili have been discovered (pilus 1, 2a and 2b), whose structural subunits are assembled in high-molecular weight polymers by specific class C sortases. In addition, the highly conserved housekeeping sortase A (SrtA), whose main role is to link surface proteins to bacterial cell wall peptidoglycan by a transpeptidation reaction, is also involved in pili cell wall anchoring in many bacteria. Through in vivo mutagenesis, we demonstrate that the LPXTG sorting signal of the minor ancillary protein (AP2) is essential for pilus 2a anchoring. We successfully produced a highly purified recombinant SrtA (SrtA(ΔN40)) able to specifically hydrolyze the sorting signal of pilus 2a minor ancillary protein (AP2-2a) and catalyze in vitro the transpeptidation reaction between peptidoglycan analogues and the LPXTG motif, using both synthetic fluorescent peptides and recombinant proteins. By contrast, SrtA(ΔN40) does not catalyze the transpeptidation reaction with substrate-peptides mimicking sorting signals of the other pilus 2a subunits (the backbone protein and the major ancillary protein). Thus, our results add further insight into the proposed model of GBS pilus 2a assembly, in which SrtA is required for pili cell wall covalent attachment, acting exclusively on the minor accessory pilin, representing the terminal subunit located at the base of the pilus.

  7. Sortase A substrate specificity in GBS pilus 2a cell wall anchoring.

    Directory of Open Access Journals (Sweden)

    Francesca Necchi

    Full Text Available Streptococcus agalactiae, also referred to as Group B Streptococcus (GBS, is one of the most common causes of life-threatening bacterial infections in infants. In recent years cell surface pili have been identified in several Gram-positive bacteria, including GBS, as important virulence factors and promising vaccine candidates. In GBS, three structurally distinct types of pili have been discovered (pilus 1, 2a and 2b, whose structural subunits are assembled in high-molecular weight polymers by specific class C sortases. In addition, the highly conserved housekeeping sortase A (SrtA, whose main role is to link surface proteins to bacterial cell wall peptidoglycan by a transpeptidation reaction, is also involved in pili cell wall anchoring in many bacteria. Through in vivo mutagenesis, we demonstrate that the LPXTG sorting signal of the minor ancillary protein (AP2 is essential for pilus 2a anchoring. We successfully produced a highly purified recombinant SrtA (SrtA(ΔN40 able to specifically hydrolyze the sorting signal of pilus 2a minor ancillary protein (AP2-2a and catalyze in vitro the transpeptidation reaction between peptidoglycan analogues and the LPXTG motif, using both synthetic fluorescent peptides and recombinant proteins. By contrast, SrtA(ΔN40 does not catalyze the transpeptidation reaction with substrate-peptides mimicking sorting signals of the other pilus 2a subunits (the backbone protein and the major ancillary protein. Thus, our results add further insight into the proposed model of GBS pilus 2a assembly, in which SrtA is required for pili cell wall covalent attachment, acting exclusively on the minor accessory pilin, representing the terminal subunit located at the base of the pilus.

  8. Auxiliary Subunits: Shepherding AMPA Receptors to the Plasma Membrane

    Directory of Open Access Journals (Sweden)

    Simon C. Haering

    2014-08-01

    Full Text Available Ionotropic glutamate receptors (iGluRs are tetrameric ligand-gated cation channels that mediate excitatory signal transmission in the central nervous system (CNS of vertebrates. The members of the iGluR subfamily of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA receptors (AMPARs mediate most of the fast excitatory signal transmission, and their abundance in the postsynaptic membrane is a major determinant of the strength of excitatory synapses. Therefore, regulation of AMPAR trafficking to the postsynaptic membrane is an important constituent of mechanisms involved in learning and memory formation, such as long-term potentiation (LTP and long-term depression (LTD. Auxiliary subunits play a critical role in the facilitation and regulation of AMPAR trafficking and function. The currently identified auxiliary subunits of AMPARs are transmembrane AMPA receptor regulatory proteins (TARPs, suppressor of lurcher (SOL, cornichon homologues (CNIHs, synapse differentiation-induced gene I (SynDIG I, cysteine-knot AMPAR modulating proteins 44 (CKAMP44, and germ cell-specific gene 1-like (GSG1L protein. In this review we summarize our current knowledge of the modulatory influence exerted by these important but still underappreciated proteins.

  9. Fungal mediator tail subunits contain classical transcriptional activation domains.

    Science.gov (United States)

    Liu, Zhongle; Myers, Lawrence C

    2015-04-01

    Classical activation domains within DNA-bound eukaryotic transcription factors make weak interactions with coactivator complexes, such as Mediator, to stimulate transcription. How these interactions stimulate transcription, however, is unknown. The activation of reporter genes by artificial fusion of Mediator subunits to DNA binding domains that bind to their promoters has been cited as evidence that the primary role of activators is simply to recruit Mediator. We have identified potent classical transcriptional activation domains in the C termini of several tail module subunits of Saccharomyces cerevisiae, Candida albicans, and Candida dubliniensis Mediator, while their N-terminal domains are necessary and sufficient for their incorporation into Mediator but do not possess the ability to activate transcription when fused to a DNA binding domain. This suggests that Mediator fusion proteins actually are functioning in a manner similar to that of a classical DNA-bound activator rather than just recruiting Mediator. Our finding that deletion of the activation domains of S. cerevisiae Med2 and Med3, as well as C. dubliniensis Tlo1 (a Med2 ortholog), impairs the induction of certain genes shows these domains function at native promoters. Activation domains within coactivators are likely an important feature of these complexes and one that may have been uniquely leveraged by a common fungal pathogen.

  10. Heterotrimeric G protein subunits are located on rat liver endosomes

    Directory of Open Access Journals (Sweden)

    Van Dyke Rebecca W

    2004-01-01

    Full Text Available Abstract Background Rat liver endosomes contain activated insulin receptors and downstream signal transduction molecules. We undertook these studies to determine whether endosomes also contain heterotrimeric G proteins that may be involved in signal transduction from G protein-coupled receptors. Results By Western blotting Gsα, Giα1,2, Giα3 and Gβ were enriched in both canalicular (CM and basolateral (BLM membranes but also readily detectable on three types of purified rat liver endosomes in the order recycling receptor compartment (RRC > compartment for uncoupling of receptor and ligand (CURL > multivesicular bodies (MVB >> purified secondary lysosomes. Western blotting with antibodies to Na, K-ATPase and to other proteins associated with plasma membranes and intracellular organelles indicated this was not due to contamination of endosome preparations by CM or BLM. Adenylate cyclase (AC was also identified on purified CM, BLM, RRC, CURL and MVB. Percoll gradient fractionation of liver postnuclear supernatants demonstrated co-occurrence of endosomes and heterotrimeric G protein subunits in fractions with little plasma membrane markers. By confocal microscopy, punctate staining for Gsα, Giα3 and Gβ corresponded to punctate areas of endocytosed Texas red-dextran in hepatocytes from control and cholera toxin-treated livers. Conclusion We conclude that heterotrimeric G protein subunits as well as AC likely traffic into hepatocytes on endosome membranes, possibly generating downstream signals spatially separate from signalling generated at the plasma membrane, analogous to the role(s of internalized insulin receptors.

  11. Thermostable cross-protective subunit vaccine against Brucella species.

    Science.gov (United States)

    Cherwonogrodzky, John W; Barabé, Nicole D; Grigat, Michelle L; Lee, William E; Poirier, Robert T; Jager, Scott J; Berger, Bradley J

    2014-12-01

    A subunit vaccine candidate was produced from Brucella suis 145 (biovar 4; expressing both the A antigen of Brucella abortus and the M antigen of Brucella melitensis). The preparation consisted mostly of polysaccharide (PS; >90% [wt/wt]; both cell-associated PS and exo-PS were combined) and a small amount of protein (1 to 3%) with no apparent nucleic acids. Vaccinated mice were protected (these had a statistically significant reduction in bacterial colonization compared to that of unvaccinated controls) when challenged with representative strains of three Brucella species most pathogenic for humans, i.e., B. abortus, B. melitensis, and B. suis. As little as 1 ng of the vaccine, without added adjuvant, protected mice against B. suis 145 infection (5 × 10(5) CFU), and a single injection of 1 μg of this subunit vaccine protected mice from B. suis 145 challenge for at least 14 months. A single immunization induced a serum IgG response to Brucella antigens that remained elevated for up to 9 weeks. The use of heat (i.e., boiling-water bath, autoclaving) in the vaccine preparation showed that it was thermostable. This method also ensured safety and security. The vaccine produced was immunogenic and highly protective against multiple strains of Brucella and represents a promising candidate for further evaluation.

  12. IMMUNOLOGICAL RESPONSE IN BOVINE LYMPH NODES STIMULATED WITH SUBUNITS VACCINES

    Directory of Open Access Journals (Sweden)

    Gabriel Andres Tafur Gomez

    2013-01-01

    Full Text Available The vaccination process belongs to the public health intervention methodologies that help prevent infections. Vaccinations performed successfully in the history of medicine reported the significance of this procedure to increase the quality of life, prevent zoonoses and improve animal production. Vaccine emergence remained without exact rules for a long time, maintaining a close relationship with pathogens. However, subunit vaccines, with a difference from the classical idea of protective immunity with microorganisms showed it is possible to trigger T-dependent responses with peptide, revealing new rules for vaccine development. This vaccination process starts by the modulation chance of adaptive immune response through peptide sequences process by APCs for immune synapse formation interceded for pMHC-TCR as a scaffold to T cells priming. In this way the immunological signal triggered by immune synapses is amplified in lymph nodes. As a consequence, T and B cells modulated by peptide activity interact between the B cell follicles region and T cell aggregates, which constitute the paracortical region of secondary lymphoid tissue to form connate unions as a prerequisite for clonal amplification and subsequent immunological memory. Indicating the knowledge of the mechanisms of immune response generated by peptides immunization is essential for understanding modulation, amplification and immune protection as demands for good subunits vaccine.

  13. Protein Kinase A Subunit Balance Regulates Lipid Metabolism in Caenorhabditis elegans and Mammalian Adipocytes.

    Science.gov (United States)

    Lee, Jung Hyun; Han, Ji Seul; Kong, Jinuk; Ji, Yul; Lv, Xuchao; Lee, Junho; Li, Peng; Kim, Jae Bum

    2016-09-23

    Protein kinase A (PKA) is a cyclic AMP (cAMP)-dependent protein kinase composed of catalytic and regulatory subunits and involved in various physiological phenomena, including lipid metabolism. Here we demonstrated that the stoichiometric balance between catalytic and regulatory subunits is crucial for maintaining basal PKA activity and lipid homeostasis. To uncover the potential roles of each PKA subunit, Caenorhabditis elegans was used to investigate the effects of PKA subunit deficiency. In worms, suppression of PKA via RNAi resulted in severe phenotypes, including shortened life span, decreased egg laying, reduced locomotion, and altered lipid distribution. Similarly, in mammalian adipocytes, suppression of PKA regulatory subunits RIα and RIIβ via siRNAs potently stimulated PKA activity, leading to potentiated lipolysis without increasing cAMP levels. Nevertheless, insulin exerted anti-lipolytic effects and restored lipid droplet integrity by antagonizing PKA action. Together, these data implicate the importance of subunit stoichiometry as another regulatory mechanism of PKA activity and lipid metabolism.

  14. Expression of accessory colonization factor subunit A (ACFA) of Vibrio cholerae and ACFA fused to cholera toxin B subunit in transgenic tomato (Solanum lycopersicum).

    Science.gov (United States)

    Sharma, Manoj Kumar; Jani, Dewal; Thungapathra, M; Gautam, J K; Meena, L S; Singh, Yogendra; Ghosh, Amit; Tyagi, Akhilesh Kumar; Sharma, Arun Kumar

    2008-05-20

    In earlier study from our group, cholera toxin B subunit had been expressed in tomato for developing a plant-based vaccine against cholera. In the present investigation, gene for accessory colonization factor (acf) subunit A, earlier reported to be essential for efficient colonization in the intestine, has been expressed in Escherichia coli as well as tomato plants. Gene encoding for a chimeric protein having a fusion of cholera toxin B subunit and accessory colonization factor A was also expressed in tomato to generate more potent combinatorial antigen. CaMV35S promoter with a duplicated enhancer sequence was used for expression of these genes in tomato. Integration of transgenes into tomato genome was confirmed by PCR and Southern hybridization. Expression of the genes was confirmed at transcript and protein levels. Accessory colonization factor A and cholera toxin B subunit fused to this protein accumulated up to 0.25% and 0.08% of total soluble protein, respectively, in the fruits of transgenic plants. Whereas protein purified from E. coli, in combination with cholera toxin B subunit can be used for development of conventional subunit vaccine, tomato fruits expressing these proteins can be used together with tomato plants expressing cholera toxin B subunit for development of oral vaccine against cholera.

  15. Rotation of subunits during catalysis by Escherichia coli F1-ATPase.

    Science.gov (United States)

    Duncan, T M; Bulygin, V V; Zhou, Y; Hutcheon, M L; Cross, R L

    1995-11-21

    During oxidative and photo-phosphorylation, F0F1-ATP synthases couple the movement of protons down an electrochemical gradient to the synthesis of ATP. One proposed mechanistic feature that has remained speculative is that this coupling process requires the rotation of subunits within F0F1. Guided by a recent, high-resolution structure for bovine F1 [Abrahams, J. P., Leslie, A. G., Lutter, R. & Walker, J. E. (1994) Nature (London) 370, 621-628], we have developed a critical test for rotation of the central gamma subunit relative to the three catalytic beta subunits in soluble F1 from Escherichia coli. In the bovine F1 structure, a specific point of contact between the gamma subunit and one of the three catalytic beta subunits includes positioning of the homolog of E. coli gamma-subunit C87 (gamma C87) close to the beta-subunit 380DELSEED386 sequence. A beta D380C mutation allowed us to induce formation of a specific disulfide bond between beta and gamma C87 in soluble E. coli F1. Formation of the crosslink inactivated beta D380C-F1, and reduction restored full activity. Using a dissociation/reassembly approach with crosslinked beta D380C-F1, we incorporated radiolabeled beta subunits into the two noncrosslinked beta-subunit positions of F1. After reduction of the initial nonradioactive beta-gamma crosslink, only exposure to conditions for catalytic turnover results in similar reactivities of unlabeled and radiolabeled beta subunits with gamma C87 upon reoxidation. The results demonstrate that gamma subunit rotates relative to the beta subunits during catalysis.

  16. 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.

  17. Structure of the human protein kinase CK2 catalytic subunit CK2α' and interaction thermodynamics with the regulatory subunit CK2β

    DEFF Research Database (Denmark)

    Bischoff, Nils; Olsen, Birgitte; Raaf, Jennifer;

    2011-01-01

    the limited biochemical knowledge about the second paralog (CK2α'), we developed a well-soluble catalytically active full-length mutant of human CK2α', characterized it by Michaelis-Menten kinetics and isothermal titration calorimetry, and determined its crystal structure to a resolution of 2 Å. The affinity......Protein kinase CK2 (formerly "casein kinase 2") is composed of a central dimer of noncatalytic subunits (CK2β) binding two catalytic subunits. In humans, there are two isoforms of the catalytic subunit (and an additional splicing variant), one of which (CK2α) is well characterized. To supplement...

  18. Effect of HMM Glutenin Subunits on Wheat Quality Attributes

    Directory of Open Access Journals (Sweden)

    Daniela Horvat

    2009-01-01

    Full Text Available Glutenin is a group of polymeric gluten proteins. Glutenin molecules consist of glutenin subunits linked together with disulphide bonds and having higher (HMM-GS and lower (LMM-GS molecular mass. The main objective of this study is the evaluation of the influence of HMM-GS on flour processing properties. Seven bread wheat genotypes with contrasting quality attributes and different HMM-GS composition were analyzed during three years. The composition and quantity of HMM-GS were determined by SDS-PAGE and RP-HPLC, respectively. The quality diversity among genotypes was estimated by the analysis of wheat grain, and flour and bread quality parameters. The presence of HMM glutenin subunits 1 and 2* at Glu-A1 and the subunits 5+10 at Glu-D1 loci, as well as a higher proportion of total HMM-GS, had a positive effect on wheat quality. Cluster analysis of the three groups of data (genotype and HMM-GS, flour and bread quality, and dough rheology yielded the same hierarchical structure for the first top three levels, and similarity of the corresponding dendrograms was proved by the principal eigenvalues of the corresponding Euclidian distance matrices. The obtained similarity in classification based on essentially different types of measurements reflects strong natural association between genetic data, product quality and physical properties. Principal component analysis (PCA was applied to effectively reduce large data set into lower dimensions of latent variables amenable for the analysis. PCA analysis of the total set of data (15 variables revealed a very strong interrelationship between the variables. The first three PCA components accounted for 96 % of the total variance, which was significant to the level of 0.05 and was considered as the level of experimental error. These data imply that the quality of wheat cultivars can be contributed to HMM-GS data and should be taken into account in breeding programs assisted by computer models with the aim to

  19. Structure–Function Relationships in Fungal Large-Subunit Catalases

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, A.; Valdez, V; Rudino-Pinera, E; Horjales, E; Hansberg, W

    2009-01-01

    Neurospora crassa has two large-subunit catalases, CAT-1 and CAT-3. CAT-1 is associated with non-growing cells and accumulates particularly in asexual spores; CAT-3 is associated with growing cells and is induced under different stress conditions. It is our interest to elucidate the structure-function relationships in large-subunit catalases. Here we have determined the CAT-3 crystal structure and compared it with the previously determined CAT-1 structure. Similar to CAT-1, CAT-3 hydrogen peroxide (H{sub 2}O{sub 2}) saturation kinetics exhibited two components, consistent with the existence of two active sites: one saturated in the millimolar range and the other in the molar range. In the CAT-1 structure, we found three interesting features related to its unusual kinetics: (a) a constriction in the channel that conveys H{sub 2}O{sub 2} to the active site; (b) a covalent bond between the tyrosine, which forms the fifth coordination bound to the iron of the heme, and a vicinal cysteine; (c) oxidation of the pyrrole ring III to form a cis-hydroxyl group in C5 and a cis-{gamma}-spirolactone in C6. The site of heme oxidation marks the starts of the central channel that communicates to the central cavity and the shortest way products can exit the active site. CAT-3 has a similar constriction in its major channel, which could function as a gating system regulated by the H{sub 2}O{sub 2} concentration before the gate. CAT-3 functional tyrosine is not covalently bonded, but has instead the electron relay mechanism described for the human catalase to divert electrons from it. Pyrrole ring III in CAT-3 is not oxidized as it is in other large-subunit catalases whose structure has been determined. Different in CAT-3 from these enzymes is an occupied central cavity. Results presented here indicate that CAT-3 and CAT-1 enzymes represent a functional group of catalases with distinctive structural characteristics that determine similar kinetics.

  20. Selective Pyramidal Cell Reduction of GABAA Receptor α1 Subunit Messenger RNA Expression in Schizophrenia

    OpenAIRE

    Glausier, Jill R; Lewis, David A.

    2011-01-01

    Levels of messenger RNA (mRNA) for the α1 subunit of the GABAA receptor, which is present in 60% of cortical GABAA receptors, have been reported to be lower in layer 3 of the prefrontal cortex (PFC) in subjects with schizophrenia. This subunit is expressed in both pyramidal cells and interneurons, and thus lower α1 subunit levels in each cell population would have opposite effects on net cortical excitation. We used dual-label in situ hybridization to quantify GABAA α1 subunit mRNA expression...

  1. Evidence for an unusual transmembrane configuration of AGG3, a Class C Gγ Subunit, of Arabidopsis

    OpenAIRE

    Wolfenstetter, Susanne; Chakravorty, David; Kula, Ryan; Urano, Daisuke; Trusov, Yuri; Sheahan, Michael B.; McCurdy, David W.; Assmann, Sarah M.; Alan M Jones; Jose R. Botella

    2014-01-01

    Heterotrimeric G proteins are crucial for the perception of external signals and subsequent signal transduction in animal and plant cells. In both model systems, the complex is comprised of one Gα, one Gβ and one Gγ subunit. However, in addition to the canonical Gγ subunits (Class A), plants also possess two unusual, plant-specific classes of Gγ subunits (Classes B and C) not yet found in animals. These include Gγ subunits lacking the C-terminal CaaX motif (Class B) which is important for mem...

  2. Subunit Characteristics of Pig Pancreas Ferritin Revealed by MALDI-TOF MS and RP-HPLC

    Institute of Scientific and Technical Information of China (English)

    HUANG Lin; LIN Zhi-cao; LIN Qing; LUO Lian-zhong; HUANG He-qing

    2008-01-01

    Pig pancreas ferritin(PPF) was purified by ultra-centrifugation,ion-exchange chromatography,and native gradient polyacrylamide gel electrophoresis(PAGENG).Sodium dodecyl sulfate(SDS)-PAGE indicates that PPF consists of two subunit types,namely,H(21000) and L(19000) subunits,and its core shows an average element composition of 1698 Fe3+ and 179 phosphate molecules within the hollow shell,giving a 9.5:1 ratio of Fe3+ to phosphate.An off line approach combining reversed-phase high-performance liquid chromatography(RP-HPLC) with matrix-assisted laser desorption ionization time of flight mass speetrometry(MALDI-TOF MS) made the decomposition of PPF shell into H and L subunits for the analysis of mass spectrometry(MS),giving molecular weights of both H(21014.4) and L(18319.9)subunits.Both subunit types were further identified by an approach combining peptide mass fingerprint(PMF) with database search.A ratio of IH to 2L subunits in PPF was determined by SDS-PAGE,RP-HPLC,and MALDI-TOF MS,respectively.It is well known that the non-covalent interaction of L-L or H-L subunits is stronger than that of H-H subunits in PPF,which may be further used to explain the unclear physiological function between H and L subunits in PPF.

  3. Composition and Content of High-Molecular-Weight Glutenin Subunits and Their Effects on Wheat Quality

    Institute of Scientific and Technical Information of China (English)

    SONG Jian-min; LIU Ai-feng; WU Xiang-yun; LIU Jian-jun; ZHAO Zhen-dong; LIU Guang-tian

    2002-01-01

    Sedimentation values, flour glutenin macropolymer (GMP) contents, composition and contents of high-molecular-weight (HMW) glutenin subunits (GS) of 233 flour samples were determined. Our data indicated that subunit 1 occurred more frequently at Glu-A1, subunit pair 7 + 8 at Glu- B1 and 2 + 12 at Glu-D1. The significant relationships between Glu-1 quality score and total HMW glutenin content, sedimentation value and GMP content suggested that the composition of HMW-GS affects wheat quality strongly. Moreover,the total content of HMW-GS was correlated with certain quality parameters more significantly. Relationship between subunit 5 + 10 content and breadmaking quality was better than others, but 2 + 12, 7 + 8, 7 + 9 and 4 + 12 also correlated with certain quality parameters significantly. The contents of total HMW-glutenin, x-type subunits and y-type subunits related with sedimentation value, flour GMP content, and Glu-1 quality score more strongly than that of individual subunit or subunit pair. The flour GMP content, with excellent correlation to sedimentation value, total contents of HMW glutenin, x- and y-type subunits and many other quality parameters, could be an ideal indicator of breadmaking quality at earlier generations for breeding purpose for its simple procedure and small scale.

  4. Genetic Diversity of High and Low Molecular Weight Glutenin Subunits in Algerian Aegilops geniculata

    Directory of Open Access Journals (Sweden)

    Asma MEDOURI

    2014-12-01

    Full Text Available Aegilops geniculata Roth is an annual grass relative to cultivated wheat and is widely distributed in North Algeria. Endosperm storage proteins of wheat and its relatives, namely glutenins and gliadins, play an important role in dough properties and bread making quality. In the present study, the different alleles encoded at the four glutenin loci (Glu-M1, Glu-U1, Glu-M3 and Glu-U3 were identified from thirty five accessions of the tetraploid wild wheat A. geniculata collected in Algeria using Sodium dodecyl Sulfate - Polyacrylamide Gel Electrophoresis (SDS-PAGE. At Glu-M1 and Glu-U1 loci, encoding high molecular weight glutenin subunits (HMW-GS or A-subunits, 15 and 12 alleles were observed respectively, including one new subunit. B-Low molecular weight glutenin subunits zone (B-LMW-GS displayed a far greater variation, as 28 and 25 alleles were identified at loci Glu-M3 and Glu-U3 respectively. Thirty two subunits patterns were revealed at the C subunits- zone and a total of thirty four patterns resulted from the genetic combination of the two zones (B- and C-zone. The wide range of glutenin subunits variation (high molecular weight glutenin subunits and low molecular weight glutenin subunits in this species has the potential to enhance the genetic variability for improving the quality of wheat./span>

  5. Tropomyosin diffusion over actin subunits facilitates thin filament assembly

    Directory of Open Access Journals (Sweden)

    Stefan Fischer

    2016-01-01

    Full Text Available Coiled-coil tropomyosin binds to consecutive actin-subunits along actin-containing thin filaments. Tropomyosin molecules then polymerize head-to-tail to form cables that wrap helically around the filaments. Little is known about the assembly process that leads to continuous, gap-free tropomyosin cable formation. We propose that tropomyosin molecules diffuse over the actin-filament surface to connect head-to-tail to partners. This possibility is likely because (1 tropomyosin hovers loosely over the actin-filament, thus binding weakly to F-actin and (2 low energy-barriers provide tropomyosin freedom for 1D axial translation on F-actin. We consider that these unique features of the actin-tropomyosin interaction are the basis of tropomyosin cable formation.

  6. Expression and secretion of cholera toxin B subunit in lactobacilli.

    Science.gov (United States)

    Okuno, Takahiro; Kashige, Nobuhiro; Satho, Tomomitsu; Irie, Keiichi; Hiramatsu, Yukihiro; Sharmin, Tanjina; Fukumitsu, Yuki; Uyeda, Saori; Yamada, Seitaro; Harakuni, Tetsuya; Miyata, Takeshi; Arakawa, Takeshi; Imoto, Masumi; Toda, Akihisa; Nakashima, Yukihiko; Miake, Fumio

    2013-01-01

    Lactic acid bacteria (LAB) are used in various fields, including in food and medical supplies. There has been a great deal of research into vaccine development using LAB as carriers due to their "generally recognized as safe" status. Cholera is an infectious disease that causes diarrhea due to cholera toxin (CT) produced by Vibrio cholerae. The pentameric cholera toxin B (CTB) subunit has no toxicity, and is used as an antigen in cholera vaccines and as a delivery molecule in vaccines to various diseases. In this study, we generated recombinant LAB expressing and secreting CTB. Here, we first report that CTB expressed and secreted from LAB bound to GM1 ganglioside. The secreted CTB was purified, and its immunogenicity was determined by intranasal administration into mice. The results of the present study suggested that it may be useful as the basis of a new oral cholera vaccine combining LAB and CTB.

  7. Thermostable Subunit Vaccines for Pulmonary Delivery: How Close Are We?

    DEFF Research Database (Denmark)

    Foged, Camilla

    2016-01-01

    -administrable, can be distributed independently of functioning freezers and refrigerators, and can be designed to induce mucosal and/or cell-mediated immunity, which is attractive for a number of diseases requiring stimulation of local mucosal immunity for protection. However, the design and delivery of thermostable...... dry powder-based vaccines represents a technological challenge: It calls for careful formulation and dosage form design, combined with cheap and efficient delivery devices, which must be engineered via a thorough understanding of the physiological barrier and the requirements for induction of mucosal...... immunity. Here, I review state of the art and perspectives in formulation design and processing methods for powder-based subunit vaccines intended for pulmonary administration, and present dry powder inhaler technologies suitable for translating these vaccines into clinical trials....

  8. Threonine 788 in integrin subunit beta1 regulates integrin activation

    DEFF Research Database (Denmark)

    Nilsson, Stina; Kaniowska, Dorota; Brakebusch, Cord

    2006-01-01

    was identified as a site with major influence on integrin function. The mutation to A788 strongly reduced beta1-dependent cell attachment and exposure of the extracellular 9EG7 epitope, whereas replacement of T789 with alanine did not interfere with the ligand-binding ability. Talin has been shown to mediate......In the present study, the functional role of suggested phosphorylation of the conserved threonines in the cytoplasmic domain of integrin subunit beta1 was investigated. Mutants mimicking phosphorylated and unphosphorylated forms of beta1 were expressed in beta1 deficient GD25 cells. T788 in beta1...... integrin activation, but the talin head domain bound equally well to the wild-type beta1 and the mutants indicating that the T788A mutation caused defect integrin activation by another mechanism. The phosphorylation-mimicking mutation T788D was fully active in promoting cell adhesion. GD25 cells expressing...

  9. Chaperonin Structure - The Large Multi-Subunit Protein Complex

    Directory of Open Access Journals (Sweden)

    Irena Roterman

    2009-03-01

    Full Text Available The multi sub-unit protein structure representing the chaperonins group is analyzed with respect to its hydrophobicity distribution. The proteins of this group assist protein folding supported by ATP. The specific axial symmetry GroEL structure (two rings of seven units stacked back to back - 524 aa each and the GroES (single ring of seven units - 97 aa each polypeptide chains are analyzed using the hydrophobicity distribution expressed as excess/deficiency all over the molecule to search for structure-to-function relationships. The empirically observed distribution of hydrophobic residues is confronted with the theoretical one representing the idealized hydrophobic core with hydrophilic residues exposure on the surface. The observed discrepancy between these two distributions seems to be aim-oriented, determining the structure-to-function relation. The hydrophobic force field structure generated by the chaperonin capsule is presented. Its possible influence on substrate folding is suggested.

  10. Glycine Receptor α2 Subunit Activation Promotes Cortical Interneuron Migration

    Directory of Open Access Journals (Sweden)

    Ariel Avila

    2013-08-01

    Full Text Available Glycine receptors (GlyRs are detected in the developing CNS before synaptogenesis, but their function remains elusive. This study demonstrates that functional GlyRs are expressed by embryonic cortical interneurons in vivo. Furthermore, genetic disruption of these receptors leads to interneuron migration defects. We discovered that extrasynaptic activation of GlyRs containing the α2 subunit in cortical interneurons by endogenous glycine activates voltage-gated calcium channels and promotes calcium influx, which further modulates actomyosin contractility to fine-tune nuclear translocation during migration. Taken together, our data highlight the molecular events triggered by GlyR α2 activation that control cortical tangential migration during embryogenesis.

  11. Tropomyosin diffusion over actin subunits facilitates thin filament assembly

    Science.gov (United States)

    Fischer, Stefan; Rynkiewicz, Michael J.; Moore, Jeffrey R.; Lehman, William

    2016-01-01

    Coiled-coil tropomyosin binds to consecutive actin-subunits along actin-containing thin filaments. Tropomyosin molecules then polymerize head-to-tail to form cables that wrap helically around the filaments. Little is known about the assembly process that leads to continuous, gap-free tropomyosin cable formation. We propose that tropomyosin molecules diffuse over the actin-filament surface to connect head-to-tail to partners. This possibility is likely because (1) tropomyosin hovers loosely over the actin-filament, thus binding weakly to F-actin and (2) low energy-barriers provide tropomyosin freedom for 1D axial translation on F-actin. We consider that these unique features of the actin-tropomyosin interaction are the basis of tropomyosin cable formation. PMID:26798831

  12. Exchangeability of the b subunit of the Cl(-)-translocating ATPase of Acetabularia acetabulum with the beta subunit of E. coli F1-ATPase: construction of the chimeric beta subunits and complementation studies.

    Science.gov (United States)

    Ikeda, M; Kadowaki, H; Ikeda, H; Moritani, C; Kanazawa, H

    1997-11-10

    The gene encoding the b subunit of the Cl(-)-translocating ATPase (aclB) was isolated from total RNA and poly(A)+ RNA of Acetabularia acetabulum and sequenced (total nucleotides of 3038 bp and an open reading frame with 478 amino acids). The deduced amino acid sequence showed high similarity to the beta subunit of the F type ATPases, but was different in the N-terminal 120 amino acids. The role of the N-terminal region was investigated using an F -ATPase beta-less mutant of E. coli, JP17. The JP17 strain expressing the aclB could not grow under conditions permitting oxidative phosphorylation, although ACLB was detected in the membrane fraction. The beta subunit was divided into three portions: amino acid position from 1 to 95 (portion A), 96 to 161 (portion B) and 162 to the C-terminus (portion C). The corresponding regions of ACLB were designated as portions A' (from 1 to 106), B' (from 107 to 172) and C' (from 173 to 478). Chimeric proteins with combinations of A-B'-C', A-B-C' and A'-B-C restored the function as the beta subunit in E. coli F0F1-complex, but those with combinations of A'-B'-C and A-B'-C had no function as the beta subunit. These findings suggested that portion B plays an important role in the assembly and function of the beta subunit in the F0F1-complex, while portion B' of ACLB exhibited inhibitory effects on assembly and function. In addition, portion A was also important for interaction of the beta subunit with the alpha subunit in E. coli F0F1-complex. These findings also suggested that the b subunit of the Cl(-)-translocating ATPase of A. acetabulum has a different function in the Cl(-)-translocating ATPase complex, although the primary structure resembled to the beta subunit of the F1-ATPase.

  13. Cross-links between ribosomal proteins of 30S subunits in 70S tight couples and in 30S subunits.

    Science.gov (United States)

    Lambert, J M; Boileau, G; Cover, J A; Traut, R R

    1983-08-01

    Ribosome 70S tight couples and 30S subunits derived from them were modified with 2-iminothiolane under conditions where about two sulfhydryl groups per protein were added to the ribosomal particles. The 70S and 30S particles were not treated with elevated concentrations of NH4Cl, in contrast to those used in earlier studies. The modified particles were oxidized to promote disulfide bond formation. Proteins were extracted from the cross-linked particles by using conditions to preclude disulfide interchange. Disulfide-linked protein complexes were fractionated on the basis of charge by electrophoresis in polyacrylamide/urea gels at pH 5.5. The proteins from sequential slices of the urea gels were analyzed by two-dimensional diagonal polyacrylamide/sodium dodecyl sulfate gel electrophoresis. Final identification of proteins in cross-linked complexes was made by radioiodination of the proteins, followed by two-dimensional polyacrylamide/urea gel electrophoresis. Attention was focused on cross-links between 30S proteins. We report the identification of 27 cross-linked dimers and 2 trimers of 30S proteins, all but one of which were found in both 70S ribosomes and free 30S subunits in similar yield. Seven of the cross-links, S3-S13, S13-S21, S14-S19, S7-S12, S9-S13, S11-S21, and S6-S18-S21, have not been reported previously when 2-iminothiolane was used. Cross-links S3-S13, S13-S21, S7-S12, S11-S21, and S6-S18-S21 are reported for the first time. The identification of the seven new cross-links is illustrated and discussed in detail. Ten of the dimers reported in the earlier studies of Sommer & Traut (1976) [Sommer, A., & Traut, R. R. (1976) J. Mol. Biol. 106, 995-1015], using 30S subunits treated with high salt concentrations, were not found in the experiments reported here.

  14. Identification of Na(+)-K(+)-ATPase beta-subunit in alveolar epithelial cells.

    Science.gov (United States)

    Zhang, X L; Danto, S I; Borok, Z; Eber, J T; Martín-Vasallo, P; Lubman, R L

    1997-01-01

    The Na(+)-K(+)-ATPase is a heterodimeric plasma membrane protein that consists of a catalytic alpha-subunit and a smaller glycosylated beta-subunit that has not been fully characterized in alveolar epithelial cells (AEC) to date. In this study, we identified the Na(+)-K(+)-ATPase beta-subunit protein in rat AEC and lung membranes using immunochemical techniques. Rat AEC grown in primary culture and rat lung, brain, and kidney membranes were solubilized in either 2% sodium dodecyl sulfate (SDS) sample buffer for SDS-polyacrylamide gel electrophoresis or in 1% Nonidet P-40 lysis buffer for immunoprecipitation studies. Na(+)-K(+)-ATPase beta-subunit was not detected in either AEC or lung membranes on Western blots when probed with a panel of antibodies (Ab) against beta-subunit isoforms, whereas brain and kidney beta-subunit were recognized as broad approximately 50-kDa bands. AEC, lung, and kidney membranes were immunoprecipitated with anti-beta Ab IEC 1/48, a monoclonal Ab that recognizes beta-subunit protein only in its undenatured state. The beta-subunit was detected in the immunoprecipitate (IP) from kidney membranes by several different anti-beta-subunit Ab. The beta-subunit was faintly detectable from AEC and lung IP as a broad approximately 50-kDa band when blotted with the polyclonal anti-beta 1-subunit Ab SpET but could not be detected by blotting with other anti-beta Ab. Treatment of the IP from kidney, lung, and AEC with N-glycosidase F for 2 h at 37 degrees C resulted in immunodetection of identical approximately 35 kDa bands when probed with all anti-beta 1 Ab on Western blots. From these results, we conclude that rat lung and AEC possess immunoreactive beta-subunit protein that is only readily detectable after deglycosylation. Because anti-beta Ab fail to detect the Na(+)-K(+)-ATPase beta-subunit in rat lung or AEC by standard Western blotting techniques under the conditions of these experiments, our results suggest that lung beta-subunit may be

  15. Glycemic Control among U.S. Hispanics/Latinos with Diabetes from the HCHS/SOL Sociocultural Ancillary Study: Do Structural and Functional Social Support Play a Role?

    Science.gov (United States)

    Fortmann, Addie L.; Roesch, Scott C.; Penedo, Frank J.; Isasi, Carmen R.; Carnethon, Mercedes R.; Corsino, Leonor; Schneiderman, Neil; Daviglus, Martha L.; Teng, Yanping; Giachello, Aida; Gonzalez, Franklyn; Gallo, Linda C.

    2014-01-01

    Background Social support is one potential source of health-related resiliency in Hispanics with diabetes. Purpose This study examined relationships of structural (i.e., social integration) and functional (i.e., perceived) social support with glycemic control (glycosylated hemoglobin; HbA1c) in the Hispanic Community Health Study/Study of Hispanics (HCHS/SOL) Sociocultural Ancillary Study. Methods This study included 766 men and women representing multiple Hispanic ethnic backgrounds, aged 18-74 years, with diagnosed diabetes who completed fasting blood draw, medication review, and measures of sociodemographic factors, medical history, structural support (Cohen Social Network Index), and functional support (Interpersonal Support Evaluation List-12). Results After adjusting for sociodemographic covariates and medication, a one standard deviation increase in functional support was related to an 0.18 % higher HbA1c (p = 0.04). A similar trend was observed for structural support; however, this effect was non-significant in adjusted models. Conclusion Greater functional support was associated with poorer glycemic control in Hispanics. PMID:25107503

  16. Fatalism and hypertension prevalence, awareness, treatment and control in US Hispanics/Latinos: results from HCHS/SOL Sociocultural Ancillary Study.

    Science.gov (United States)

    Gutierrez, Angela P; McCurley, Jessica L; Roesch, Scott C; Gonzalez, Patricia; Castañeda, Sheila F; Penedo, Frank J; Gallo, Linda C

    2016-08-08

    Compared with non-Hispanic whites, US Hispanics/Latinos display similar hypertension prevalence, but lower awareness, treatment, and control. Sociocultural factors may affect these patterns. Fatalism, the belief that health is predetermined by fate, relates to poorer adoption of risk reducing health behaviors. We examined the association of fatalism with hypertension prevalence, awareness, treatment, and control among 5313 Hispanics/Latinos, ages 18-74, who were enrolled from four US communities in the Hispanic Community Health Study/Study of Latinos Sociocultural Ancillary Study. After accounting for socioeconomic status and acculturation in logistic regression analyses, higher fatalism was associated with increased odds of hypertension (OR 1.14, 95 % CI 1.02, 1.28). This association was non-significant when diabetes and other health-related covariates were statistically adjusted. Fatalism was not associated with hypertension awareness, treatment, or control. Findings suggest that the association of fatalism with hypertension may be due largely to its association with SES, acculturation, or related health conditions.

  17. Model-Based Estimation of Forest Canopy Height in Red and Austrian Pine Stands Using Shuttle Radar Topography Mission and Ancillary Data: a Proof-of-Concept Study

    Energy Technology Data Exchange (ETDEWEB)

    Brown Jr., C G; Sarabandi, K; Pierce, L E

    2007-04-06

    In this paper, accurate tree stand height retrieval is demonstrated using C-band Shuttle Radar Topography Mission (SRTM) height and ancillary data. The tree height retrieval algorithm is based on modeling uniform tree stands with a single layer of randomly oriented vegetation particles. For such scattering media, the scattering phase center height, as measured by SRTM, is a function of tree height, incidence angle, and the extinction coefficient of the medium. The extinction coefficient for uniform tree stands is calculated as a function of tree height and density using allometric equations and a fractal tree model. The accuracy of the proposed algorithm is demonstrated using SRTM and TOPSAR data for 15 red pine and Austrian pine stands (TOPSAR is an airborne interferometric synthetic aperture radar). The algorithm yields root-mean-square (rms) errors of 2.5-3.6 m, which is a substantial improvement over the 6.8-8.3-m rms errors from the raw SRTM minus National Elevation Dataset Heights.

  18. Correlating excited state and charge carrier dynamics with photovoltaic parameters of perylene dye sensitized solar cells: influences of an alkylated carbazole ancillary electron-donor.

    Science.gov (United States)

    Li, Yang; Wang, Junting; Yuan, Yi; Zhang, Min; Dong, Xiandui; Wang, Peng

    2017-01-18

    Two perylene dyes characteristic of electron-donors phenanthrocarbazole (PC) and carbazyl functionalized PC are selected to study the complicated dynamics of excited states and charge carriers, which underlie the photovoltaic parameters of dye-sensitized solar cells (DSCs). We have combined femtosecond fluorescence up-conversion and time-resolved single-photon counting techniques to probe the wavelength-dependent photoluminescence dynamics of dye molecules not only dissolved in THF but also grafted on the surface of oxide nanoparticles. Excited state relaxation and electron injection both occur on a similar timescale, resulting in a very distributive kinetics of electron injection. It is also found that the carbazyl ancillary electron-donor causes a faster electron injection, which over-compensates the adverse impact of a slightly shorter lifetime of the equilibrium excited state. Nanosecond transient absorption and transient photovoltage decay measurements have shown that conjugating carbazyl to PC can effectively slow down the kinetics of charge recombination of electrons in titania with both photo-oxidized dye molecules and triiodide anions, improving the cell photovoltage.

  19. Machismo, Marianismo, and Negative Cognitive-Emotional Factors: Findings From the Hispanic Community Health Study/Study of Latinos Sociocultural Ancillary Study.

    Science.gov (United States)

    Nuñez, Alicia; González, Patricia; Talavera, Gregory A; Sanchez-Johnsen, Lisa; Roesch, Scott C; Davis, Sonia M; Arguelles, William; Womack, Veronica Y; Ostrovsky, Natania W; Ojeda, Lizette; Penedo, Frank J; Gallo, Linda C

    2016-11-01

    There is limited research on the traditional Hispanic male and female gender roles of machismo and marianismo, respectively, in relation to negative cognitions and emotions. Given the vulnerability of Hispanics to negative cognitions and emotions, it is important to examine sociocultural correlates of emotional distress. Therefore, we examined associations of machismo and marianismo with negative cognitive-emotional factors (i.e., depression symptoms; cynical hostility; and trait anxiety and anger) in the Hispanic Community Health Study/Study of Latinos Sociocultural Ancillary Study, a cross-sectional cohort study of sociocultural and psychosocial correlates of cardiometabolic health. Participants were aged 18-74 years and self-identified as Hispanic of Central American, Cuban, Dominican, Mexican, Puerto Rican, South American, and other Hispanic background (N = 4,426). Results revealed that specific components of machismo (traditional machismo) and marianismo (family and spiritual pillar dimensions) were associated with higher levels of negative cognitions and emotions after adjusting for socio-demographic factors (p < .05); these associations remained consistent across sex, Hispanic background group, and acculturation. Findings can inform mental health interventions and contribute to our understanding of the importance of gender role socialization in the context of self-reported negative cognitive-emotional factors in Hispanics.

  20. Factor structure of the Perceived Stress Scale-10 (PSS) across English and Spanish language responders in the HCHS/SOL Sociocultural Ancillary Study.

    Science.gov (United States)

    Perera, Marisa J; Brintz, Carrie E; Birnbaum-Weitzman, Orit; Penedo, Frank J; Gallo, Linda C; Gonzalez, Patricia; Gouskova, Natalia; Isasi, Carmen R; Navas-Nacher, Elena L; Perreira, Krista M; Roesch, Scott C; Schneiderman, Neil; Llabre, Maria M

    2017-03-01

    Despite widespread use, psychometric investigation of the original English and translated Spanish versions of the 10-item Perceived Stress Scale (PSS; Cohen, Kamarck, & Mermelstein, 1983) has been limited among the U.S. Hispanic/Latino population. The present study examined the factor structure, factorial invariance, and reliability and validity of PSS scores from English and Spanish versions using data from 5,176 Hispanics/Latinos who participated in the Hispanic Community Health Study/Study of Latinos Sociocultural Ancillary Study. The total sample and language multigroup confirmatory factor analyses supported a bifactor model with all 10 PSS items loading on a general perceived stress factor, and the 4 reverse-worded items also loading on a reverse-worded factor. Internal consistency ranged from .68 to .78, and it was indicated that reliable variance exists beyond the general perceived stress factor. The model displayed configural, metric, scalar, and residual invariance across language groups. Convergent validity analyses indicated that both the general perceived stress factor and the reverse-worded factor were related to scores of depression, anxiety, and anger in the expected directions. The reverse-worded factor added to the validity of the PSS beyond the general perceived stress factor. The total computed score of the PSS can be recommended for use with Hispanics/Latinos in the United States that complete the measure in English or Spanish and the reverse-worded factor can enhance prediction. (PsycINFO Database Record

  1. 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.

  2. Specific Inhibition of Herpes Simplex Virus DNA Polymerase by Helical Peptides Corresponding to the Subunit Interface

    Science.gov (United States)

    Digard, Paul; Williams, Kevin P.; Hensley, Preston; Brooks, Ian S.; Dahl, Charles E.; Coen, Donald M.

    1995-02-01

    The herpes simplex virus DNA polymerase consists of two subunits-a catalytic subunit and an accessory subunit, UL42, that increases processivity. Mutations affecting the extreme C terminus of the catalytic subunit specifically disrupt subunit interactions and ablate virus replication, suggesting that new antiviral drugs could be rationally designed to interfere with polymerase heterodimerization. To aid design, we performed circular dichroism (CD) spectroscopy and analytical ultracentrifugation studies, which revealed that a 36-residue peptide corresponding to the C terminus of the catalytic subunit folds into a monomeric structure with partial α-helical character. CD studies of shorter peptides were consistent with a model where two separate regions of α-helix interact to form a hairpin-like structure. The 36-residue peptide and a shorter peptide corresponding to the C-terminal 18 residues blocked UL42-dependent long-chain DNA synthesis at concentrations that had no effect on synthesis by the catalytic subunit alone or by calf thymus DNA polymerase δ and its processivity factor. These peptides, therefore, represent a class of specific inhibitors of herpes simplex virus DNA polymerase that act by blocking accessory-subunit-dependent synthesis. These peptides or their structures may form the basis for the synthesis of clinically effective drugs.

  3. Positive modulation of delta-subunit containing GABAA receptors in mouse neurons

    DEFF Research Database (Denmark)

    Vardya, Irina; Hoestgaard-Jensen, Kirsten; Nieto-Gonzalez, Jose Luis;

    2012-01-01

    δ-subunit containing extrasynaptic GABA(A) receptors are potential targets for modifying neuronal activity in a range of brain disorders. With the aim of gaining more insight in synaptic and extrasynaptic inhibition, we used a new positive modulator, AA29504, of δ-subunit containing GABA(A) recep...

  4. Incorporation of high-molecular-weight glutenin subunits into doughs using 2 gram mixograph and extensigraphs

    Science.gov (United States)

    To study the contributions of high-molecular-weight glutenin subunits (HMW-GS) to the gluten macropolymer and dough properties, wheat HMW-GS (x- and y-types) are synthesized in a bacterial expression system. These subunits are then purified and used to supplement dough mixing and extensigraph exper...

  5. 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...

  6. Regulation of Voltage-Activated K(+) Channel Gating by Transmembrane β Subunits.

    Science.gov (United States)

    Sun, Xiaohui; Zaydman, Mark A; Cui, Jianmin

    2012-01-01

    Voltage-activated K(+) (K(V)) channels are important for shaping action potentials and maintaining resting membrane potential in excitable cells. K(V) channels contain a central pore-gate domain (PGD) surrounded by four voltage-sensing domains (VSDs). The VSDs will change conformation in response to alterations of the membrane potential thereby inducing the opening of the PGD. Many K(V) channels are heteromeric protein complexes containing auxiliary β subunits. These β subunits modulate channel expression and activity to increase functional diversity and render tissue specific phenotypes. This review focuses on the K(V) β subunits that contain transmembrane (TM) segments including the KCNE family and the β subunits of large conductance, Ca(2+)- and voltage-activated K(+) (BK) channels. These TM β subunits affect the voltage-dependent activation of K(V) α subunits. Experimental and computational studies have described the structural location of these β subunits in the channel complexes and the biophysical effects on VSD activation, PGD opening, and VSD-PGD coupling. These results reveal some common characteristics and mechanistic insights into K(V) channel modulation by TM β subunits.

  7. Regulation of KV channel voltage-dependent activation by transmembrane β subunits

    Directory of Open Access Journals (Sweden)

    Xiaohui eSun

    2012-04-01

    Full Text Available Voltage-activated K+ (KV channels are important for shaping action potentials and maintaining resting membrane potential in excitable cells. KV channels contain a central pore-gate domain (PGD surrounded by four voltage-sensing domains (VSD. The VSDs will change conformation in response to alterations of the membrane potential thereby inducing the opening of the PGD. Many KV channels are heteromeric protein complexes containing auxiliary β subunits. These β subunits modulate channel expression and activity to increase functional diversity and render tissue specific phenotypes. This review focuses on the KV β subunits that contain transmembrane (TM segments including the KCNE family and the β subunits of large conductance, Ca2+- and voltage-activated K+ (BK channels. These TM β subunits affect the voltage-dependent activation of KV α subunits. Experimental and computational studies have described the structural location of these β subunits in the channel complexes and the biophysical effects on VSD activation, PGD opening and VSD-PGD coupling. These results reveal some common characteristics and mechanistic insights into KV channel modulation by TM β subunits.

  8. Archaeal type IV pili and their involvement in biofilm formation.

    Science.gov (United States)

    Pohlschroder, Mechthild; Esquivel, Rianne N

    2015-01-01

    Type IV pili are ancient proteinaceous structures present on the cell surface of species in nearly all bacterial and archaeal phyla. These filaments, which are required for a diverse array of important cellular processes, are assembled employing a conserved set of core components. While type IV pilins, the structural subunits of pili, share little sequence homology, their signal peptides are structurally conserved allowing for in silico prediction. Recently, in vivo studies in model archaea representing the euryarchaeal and crenarchaeal kingdoms confirmed that several of these pilins are incorporated into type IV adhesion pili. In addition to facilitating surface adhesion, these in vivo studies also showed that several predicted pilins are required for additional functions that are critical to biofilm formation. Examples include the subunits of Sulfolobus acidocaldarius Ups pili, which are induced by exposure to UV light and promote cell aggregation and conjugation, and a subset of the Haloferax volcanii adhesion pilins, which play a critical role in microcolony formation while other pilins inhibit this process. The recent discovery of novel pilin functions such as the ability of haloarchaeal adhesion pilins to regulate swimming motility may point to novel regulatory pathways conserved across prokaryotic domains. In this review, we will discuss recent advances in our understanding of the functional roles played by archaeal type IV adhesion pili and their subunits, with particular emphasis on their involvement in biofilm formation.

  9. Structural characterization of recombinant crustacyanin subunits from the lobster Homarus americanus.

    Science.gov (United States)

    Ferrari, Michele; Folli, Claudia; Pincolini, Elisa; McClintock, Timothy S; Rössle, Manfred; Berni, Rodolfo; Cianci, Michele

    2012-08-01

    Crustacean crustacyanin proteins are linked to the production and modification of carapace colour, with direct implications for fitness and survival. Here, the structural and functional properties of the two recombinant crustacyanin subunits H(1) and H(2) from the American lobster Homarus americanus are reported. The two subunits are structurally highly similar to the corresponding natural apo crustacyanin CRTC and CRTA subunits from the European lobster H. gammarus. Reconstitution studies of the recombinant crustacyanin proteins H(1) and H(2) with astaxanthin reproduced the bathochromic shift of 85-95 nm typical of the natural crustacyanin subunits from H. gammarus in complex with astaxanthin. Moreover, correlations between the presence of crustacyanin genes in crustacean species and the resulting carapace colours with the spectral properties of the subunits in complex with astaxanthin confirmed this genotype-phenotype linkage.

  10. Association of condensin with chromosomes depends on DNA binding by its HEAT-repeat subunits.

    Science.gov (United States)

    Piazza, Ilaria; Rutkowska, Anna; Ori, Alessandro; Walczak, Marta; Metz, Jutta; Pelechano, Vicent; Beck, Martin; Haering, Christian H

    2014-06-01

    Condensin complexes have central roles in the three-dimensional organization of chromosomes during cell divisions, but how they interact with chromatin to promote chromosome segregation is largely unknown. Previous work has suggested that condensin, in addition to encircling chromatin fibers topologically within the ring-shaped structure formed by its SMC and kleisin subunits, contacts DNA directly. Here we describe the discovery of a binding domain for double-stranded DNA formed by the two HEAT-repeat subunits of the Saccharomyces cerevisiae condensin complex. From detailed mapping data of the interfaces between the HEAT-repeat and kleisin subunits, we generated condensin complexes that lack one of the HEAT-repeat subunits and consequently fail to associate with chromosomes in yeast and human cells. The finding that DNA binding by condensin's HEAT-repeat subunits stimulates the SMC ATPase activity suggests a multistep mechanism for the loading of condensin onto chromosomes.

  11. HMW glutenin subunits in multiploid Aegilops species: composition analysis and molecular cloning of coding sequences

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Aegilops genus contains species closely related to wheat. Incommon with wheat, Aegilops species accumulate high molecular weight (HMW) glutenin subunits in their endospermic tissue. In this study, we investigated the composition of HMW glutenin subunits in four multiploid Aegilops species using SDS-PAGE analysis. Furthermore, by working with Ae. ventricosa, we established an efficient genomic PCR condition for simultaneous amplification of DNA sequences coding for either x-ory-type HMW glutenin subunits from polyploid Aegilops species. Using the genomic PCR condition, we amplified and subsequently cloned two DNA fragments that may code for HMW glutenin subunits in Ae. ventricosa. Based on an analysis of the deduced amino acid sequences, we concluded that the two cloned sequences encode one x- and one y-type of HMW glutenin subunit, respectively.

  12. SB-205384 Is a Positive Allosteric Modulator of Recombinant GABAA Receptors Containing Rat α3, α5, or α6 Subunit Subtypes Coexpressed with β3 and γ2 Subunits

    OpenAIRE

    Heidelberg, Laura S.; Warren, James W.; Fisher, Janet L.

    2013-01-01

    Many drugs used to treat anxiety are positive modulators of GABAA receptors, which mediate fast inhibitory neurotransmission. The GABAA receptors can be assembled from a combination of at least 16 different subunits. The receptor’s subunit composition determines its pharmacologic and functional properties, and subunit expression varies throughout the brain. A primary goal for new treatments targeting GABAA receptors is the production of subunit-selective modulators acting upon a discrete popu...

  13. 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.

  14. Expansion of transducin subunit gene families in early vertebrate tetraploidizations.

    Science.gov (United States)

    Lagman, David; Sundström, Görel; Ocampo Daza, Daniel; Abalo, Xesús M; Larhammar, Dan

    2012-10-01

    Hundreds of gene families expanded in the early vertebrate tetraploidizations including many gene families in the phototransduction cascade. We have investigated the evolution of the heterotrimeric G-proteins of photoreceptors, the transducins, in relation to these events using both phylogenetic analyses and synteny comparisons. Three alpha subunit genes were identified in amniotes and the coelacanth, GNAT1-3; two of these were identified in amphibians and teleost fish, GNAT1 and GNAT2. Most tetrapods have four beta genes, GNB1-4, and teleosts have additional duplicates. Finally, three gamma genes were identified in mammals, GNGT1, GNG11 and GNGT2. Of these, GNGT1 and GNGT2 were found in the other vertebrates. In frog and zebrafish additional duplicates of GNGT2 were identified. Our analyses show all three transducin families expanded during the early vertebrate tetraploidizations and the beta and gamma families gained additional copies in the teleost-specific genome duplication. This suggests that the tetraploidizations contributed to visual specialisations.

  15. DNA binding properties of the small cascade subunit Csa5.

    Directory of Open Access Journals (Sweden)

    Michael Daume

    Full Text Available CRISPR-Cas systems provide immunity against viral attacks in archaeal and bacterial cells. Type I systems employ a Cas protein complex termed Cascade, which utilizes small CRISPR RNAs to detect and degrade the exogenic DNA. A small sequence motif, the PAM, marks the foreign substrates. Previously, a recombinant type I-A Cascade complex from the archaeon Thermoproteus tenax was shown to target and degrade DNA in vitro, dependent on a native PAM sequence. Here, we present the biochemical analysis of the small subunit, Csa5, of this Cascade complex. T. tenax Csa5 preferentially bound ssDNA and mutants that showed decreased ssDNA-binding and reduced Cascade-mediated DNA cleavage were identified. Csa5 oligomerization prevented DNA binding. Specific recognition of the PAM sequence was not observed. Phylogenetic analyses identified Csa5 as a universal member of type I-A systems and revealed three distinct groups. A potential role of Csa5 in R-loop stabilization is discussed.

  16. Design of a hyperstable 60-subunit protein icosahedron

    Science.gov (United States)

    Hsia, Yang; Bale, Jacob B.; Gonen, Shane; Shi, Dan; Sheffler, William; Fong, Kimberly K.; Nattermann, Una; Xu, Chunfu; Huang, Po-Ssu; Ravichandran, Rashmi; Yi, Sue; Davis, Trisha N.; Gonen, Tamir; King, Neil P.; Baker, David

    2016-07-01

    The icosahedron is the largest of the Platonic solids, and icosahedral protein structures are widely used in biological systems for packaging and transport. There has been considerable interest in repurposing such structures for applications ranging from targeted delivery to multivalent immunogen presentation. The ability to design proteins that self-assemble into precisely specified, highly ordered icosahedral structures would open the door to a new generation of protein containers with properties custom-tailored to specific applications. Here we describe the computational design of a 25-nanometre icosahedral nanocage that self-assembles from trimeric protein building blocks. The designed protein was produced in Escherichia coli, and found by electron microscopy to assemble into a homogenous population of icosahedral particles nearly identical to the design model. The particles are stable in 6.7 molar guanidine hydrochloride at up to 80 degrees Celsius, and undergo extremely abrupt, but reversible, disassembly between 2 molar and 2.25 molar guanidinium thiocyanate. The icosahedron is robust to genetic fusions: one or two copies of green fluorescent protein (GFP) can be fused to each of the 60 subunits to create highly fluorescent ‘standard candles’ for use in light microscopy, and a designed protein pentamer can be placed in the centre of each of the 20 pentameric faces to modulate the size of the entrance/exit channels of the cage. Such robust and customizable nanocages should have considerable utility in targeted drug delivery, vaccine design and synthetic biology.

  17. 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...

  18. trt-1 is the Caenorhabditis elegans catalytic subunit of telomerase.

    Directory of Open Access Journals (Sweden)

    Bettina Meier

    2006-02-01

    Full Text Available Mutants of trt-1, the Caenorhabditis elegans telomerase reverse transcriptase, reproduce normally for several generations but eventually become sterile as a consequence of telomere erosion and end-to-end chromosome fusions. Telomere erosion and uncapping do not cause an increase in apoptosis in the germlines of trt-1 mutants. Instead, late-generation trt-1 mutants display chromosome segregation defects that are likely to be the direct cause of sterility. trt-1 functions in the same telomere replication pathway as mrt-2, a component of the Rad9/Rad1/Hus1 (9-1-1 proliferating cell nuclear antigen-like sliding clamp. Thus, the 9-1-1 complex may be required for telomerase to act at chromosome ends in C. elegans. Although telomere erosion limits replicative life span in human somatic cells, neither trt-1 nor telomere shortening affects postmitotic aging in C. elegans. These findings illustrate effects of telomere dysfunction in C. elegans mutants lacking the catalytic subunit of telomerase, trt-1.

  19. Structure of the Tribolium castaneum Telomerase Catalytic Subunit TERT

    Energy Technology Data Exchange (ETDEWEB)

    Gillis,A.; Schuller, A.; Skordalakes, E.

    2008-01-01

    A common hallmark of human cancers is the overexpression of telomerase, a ribonucleoprotein complex that is responsible for maintaining the length and integrity of chromosome ends. Telomere length deregulation and telomerase activation is an early, and perhaps necessary, step in cancer cell evolution. Here we present the high-resolution structure of the Tribolium castaneum catalytic subunit of telomerase, TERT. The protein consists of three highly conserved domains, organized into a ring-like structure that shares common features with retroviral reverse transcriptases, viral RNA polymerases and B-family DNA polymerases. Domain organization places motifs implicated in substrate binding and catalysis in the interior of the ring, which can accommodate seven to eight bases of double-stranded nucleic acid. Modelling of an RNA-DNA heteroduplex in the interior of this ring demonstrates a perfect fit between the protein and the nucleic acid substrate, and positions the 3'-end of the DNA primer at the active site of the enzyme, providing evidence for the formation of an active telomerase elongation complex.

  20. On the evolution of the single-subunit RNA polymerases.

    Science.gov (United States)

    Cermakian, N; Ikeda, T M; Miramontes, P; Lang, B F; Gray, M W; Cedergren, R

    1997-12-01

    Many eukaryotic nuclear genomes as well as mitochondrial plasmids contain genes displaying evident sequence similarity to those encoding the single-subunit RNA polymerase (ssRNAP) of bacteriophage T7 and its relatives. We have collected and aligned these ssRNAP sequences and have constructed unrooted phylogenetic trees that demonstrate the separation of ssRNAPs into three well-defined and nonoverlapping clusters (phage-encoded, nucleus-encoded, and plasmid-encoded). Our analyses indicate that these three subfamiles of T7-like RNAPs shared a common ancestor; however, the order in which the groups diverged cannot be inferred from available data. On the basis of structural similarities and mutational data, we suggest that the ancestral ssRNAP gene may have arisen via duplication and divergence of a DNA polymerase or reverse transcriptase gene. Considering the current phylogenetic distribution of ssRNAP sequences, we further suggest that the origin of the ancestral ssRNAP gene closely paralleled in time the introduction of mitochondria into eukaryotic cells through a eubacterial endosymbiosis.

  1. The spectrum of EWSR1-rearranged neoplasms at a tertiary sarcoma centre; assessing 772 tumour specimens and the value of current ancillary molecular diagnostic modalities

    Science.gov (United States)

    Noujaim, Jonathan; Jones, Robin L; Swansbury, John; Gonzalez, David; Benson, Charlotte; Judson, Ian; Fisher, Cyril; Thway, Khin

    2017-01-01

    Background: EWSR1 rearrangements were first identified in Ewing sarcoma, but the spectrum of EWSR1-rearranged neoplasms now includes many soft tissue tumour subtypes including desmoplastic small round cell tumour (DSRCT), myxoid liposarcoma (MLPS), extraskeletal myxoid chondrosarcoma (EMC), angiomatoid fibrous histiocytoma (AFH), clear cell sarcoma (CCS) and myoepithelial neoplasms. We analysed the spectrum of EWSR1-rearranged soft tissue neoplasms at our tertiary sarcoma centre, by assessing ancillary molecular diagnostic modalities identifying EWSR1-rearranged tumours and reviewing the results in light of our current knowledge of these and other Ewing sarcoma-like neoplasms. Methods: We retrospectively analysed all specimens tested for EWSR1 rearrangements by fluorescence in situ hybridisation (FISH) and/or reverse transcription–PCR (RT–PCR) over a 7-year period. Results: There was a total of 772 specimens. FISH was performed more often than RT–PCR (n=753, 97.5% vs n=445, 57.6%). In total, 210 (27.9%) specimens were FISH-positive for EWSR1 rearrangement compared to 111 (14.4%) that showed EWSR1 fusion transcripts with RT–PCR. Failure rates for FISH and RT–PCR were 2.5% and 18.0%. Of 109 round cell tumours with pathology consistent with Ewing sarcoma, 15 (13.8 %) cases were FISH-positive without an identifiable EWSR1 fusion transcript, 4 (3.7%) were FISH-negative but RT–PCR positive and 4 (3.7%) were negative for both. FISH positivity for DSRCT, MLPS, EMC, AFH and CCS was 86.3%, 4.3%, 58.5%, 60.0% and 87.9%, respectively. A positive FISH result led to diagnostic change in 40 (19.0%) EWSR1-rearranged cases. 13 FISH-positive cases remained unclassifiable. Conclusions: FISH is more sensitive for identifying EWSR1 rearrangements than RT–PCR. However, there can be significant morphologic and immunohistochemical overlap between groups of EWSR1-rearranged neoplasms, with important prognostic and therapeutic implications. FISH and RT–PCR should be used as

  2. The health care needs of the physically disabled patient in a home-based care environment: Implications for the training of ancillary health care workers

    Directory of Open Access Journals (Sweden)

    Monica Springe

    2010-03-01

    Full Text Available According to existing literature, ancillary health care workers (AHCWs often do not meet the health care needs of patients with physical disabilities (physically disabled patients in a homebased environment, because of inadequate training programmes. The purpose of this research study was to explore the health care needs of physically disabled patients in long-term, home-based care in the northern suburbs of Johannesburg and, based on results, to offer recommendations for the training of AHCWs. Qualitative, exploratory, descriptive and contextual means were employed in data collection and analysis. The population consisted of eight physically disabled participants who employed an AHCW to assist them with their long-term home care. Purposive sampling was used with subsequent snowballing to identify further participants for the study. Individual interviews were conducted, where participants had to answer the questions (1‘What are your health care needs?’ and(2 ‘How should these be met?’ Data saturation was ensured, after which Tesch’s method of data analysis was followed. Three categories of health care needs were identified (1 physical health care needs, (2 interpersonal relationship needs and (3 social needs, and 12 themes were derived from these categories. These categories of health care needs should be addressed in the training of AHCWs.From the themes, recommendations were described for the training of AHCWs on the health care needs of the home-based physically disabled patients. The AHCW should assist in the adaptation of the environment to the patient’s individual needs, and should use knowledge and critical thinking skills to ensure a patient-centred care setting.

    Opsomming

    Volgens die literatuur kan assistentgesondheidsorgwerkers (AGWs, as gevolg van ontoereikende opleiding, nie altyd aan die behoeftes van fisies gestremde pasiënte in 'n tuisopset voldoen nie.Die doel van hierdie navorsingstudie was

  3. 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.

  4. Mapping of a conformational epitope on the cashew allergen Ana o 2: a discontinuous large subunit epitope dependent upon homologous or heterologous small subunit association.

    Science.gov (United States)

    Xia, Lixin; Willison, LeAnna N; Porter, Lauren; Robotham, Jason M; Teuber, Suzanne S; Sathe, Shridhar K; Roux, Kenneth H

    2010-05-01

    The 11S globulins are members of the cupin protein superfamily and represent an important class of tree nut allergens for which a number of linear epitopes have been mapped. However, specific conformational epitopes for these allergens have yet to be described. We have recently reported a cashew Ana o 2 conformational epitope defined by murine mAb 2B5 and competitively inhibited by a subset of patient IgE antibodies. The 2B5 epitope appears to reside on the large (acidic) subunit, is dependent upon small (basic) subunit association for expression, and is highly susceptible to denaturation. Here we fine map the epitope using a combination of recombinant chimeric cashew Ana o 2-soybean Gly m 6 chimeras, deletion and point mutations, molecular modeling, and electron microscopy of 2B5-Ana o 2 immune complexes. Key residues appear confined to a 24 amino acid segment near the N-terminus of the large subunit peptide, a portion of which makes direct contact with the small subunit. These data provide an explanation for both the small subunit dependence and the structurally labile nature of the epitope.

  5. Reaction of BH4- with [Mo2Cp2(mu-SMe)n] species to give tetrahydroborato, hydrido or dimetallaborane compounds: control of product by ancillary ligands.

    Science.gov (United States)

    Cabon, Nolwenn; Petillon, Francois Y; Schollhammer, Philippe; Talarmin, Jean; Muir, Kenneth W

    2004-09-07

    The reaction of mono- or dichloro-dimolybdenum(III) complexes [Mo2Cp2(mu-SMe)2(mu-Cl)(mu-Y)] (Cp=eta5-C5H5; 1, Y=SMe; 2, Y=PPh2; 3, Y=Cl) with NaBH4 at room temperature gave in high yields tetrahydroborato (8), hydrido (9) or metallaborane (12) complexes depending on the ancillary ligands. The correct formulation of derivatives and has been unambigously determined by X-ray diffraction methods. That of the hydrido compound 9 has been established in solution by NMR analysis and confirmed by an X-ray study of the mu-azavinylidene derivative [Mo2Cp2(mu-SMe)2(mu-PPh2)(mu-N=CHMe)] (10) obtained from the insertion of acetonitrile into the Mo-H bond of 9. Reaction of NaBH4 with nitrile derivatives, [Mo2Cp2(mu-SMe)4-n(CH3CN)2n]n+(5, n=1; 6 n=2), afforded the tetrahydroborato compound 8, together with a mu-azavinylidene species [Mo2Cp2(mu-SMe)3(mu-N=CHMe)](14), when n=1, and the metallaborane complex 12, together with a mixed borohydrato-azavinylidene derivative [Mo2Cp2(mu-SMe)2(mu-BH4)(mu-N=CHMe)] (13), when n=2. The molecular structures of these complexes have been confirmed by X-ray analysis. Preparations of some of the starting complexes (3 and 4) are also described, as are the molecular structures of the precursors [Mo2Cp2(mu-SMe)2(mu-X)(mu-Y)] (1, X/Y=Cl/SMe; 2, X/Y=Cl/PPh2; 4, X/Y=SMe/PPh2).

  6. Sugar-sweetened beverage intake and cardiovascular risk factor profile in youth with type 1 diabetes: application of measurement error methodology in the SEARCH Nutrition Ancillary Study.

    Science.gov (United States)

    Liese, Angela D; Crandell, Jamie L; Tooze, Janet A; Kipnis, Victor; Bell, Ronny; Couch, Sarah C; Dabelea, Dana; Crume, Tessa L; Mayer-Davis, Elizabeth J

    2015-08-14

    The SEARCH Nutrition Ancillary Study aims to investigate the role of dietary intake on the development of long-term complications of type 1 diabetes in youth, and capitalise on measurement error (ME) adjustment methodology. Using the National Cancer Institute (NCI) method for episodically consumed foods, we evaluated the relationship between sugar-sweetened beverage (SSB) intake and cardiovascular risk factor profile, with the application of ME adjustment methodology. The calibration sample included 166 youth with two FFQ and three 24 h dietary recall data within 1 month. The full sample included 2286 youth with type 1 diabetes. SSB intake was significantly associated with higher TAG, total and LDL-cholesterol concentrations, after adjusting for energy, age, diabetes duration, race/ethnicity, sex and education. The estimated effect size was larger (model coefficients increased approximately 3-fold) after the application of the NCI method than without adjustment for ME. Compared with individuals consuming one serving of SSB every 2 weeks, those who consumed one serving of SSB every 2 d had 3.7 mg/dl (0.04 mmol/l) higher TAG concentrations and 4.0 mg/dl (0.10 mmol/l) higher total cholesterol and LDL-cholesterol concentrations, after adjusting for ME and covariates. SSB intake was not associated with measures of adiposity and blood pressure. Our findings suggest that SSB intake is significantly related to increased lipid levels in youth with type 1 diabetes, and that estimates of the effect size of SSB on lipid levels are severely attenuated in the presence of ME. Future studies in youth with diabetes should consider a design that will allow for the adjustment for ME when studying the influence of diet on health status.

  7. Optimal policies for simultaneous energy consumption and ancillary service provision for flexible loads under stochastic prices and no capacity reservation constraint

    Science.gov (United States)

    Kefayati, Mahdi; Baldick, Ross

    2015-07-01

    Flexible loads, i.e. the loads whose power trajectory is not bound to a specific one, constitute a sizable portion of current and future electric demand. This flexibility can be used to improve the performance of the grid, should the right incentives be in place. In this paper, we consider the optimal decision making problem faced by a flexible load, demanding a certain amount of energy over its availability period, subject to rate constraints. The load is also capable of providing ancillary services (AS) by decreasing or increasing its consumption in response to signals from the independent system operator (ISO). Under arbitrarily distributed and correlated Markovian energy and AS prices, we obtain the optimal policy for minimising expected total cost, which includes cost of energy and benefits from AS provision, assuming no capacity reservation requirement for AS provision. We also prove that the optimal policy has a multi-threshold form and can be computed, stored and operated efficiently. We further study the effectiveness of our proposed optimal policy and its impact on the grid. We show that, while optimal simultaneous consumption and AS provision under real-time stochastic prices are achievable with acceptable computational burden, the impact of adopting such real-time pricing schemes on the network might not be as good as suggested by the majority of the existing literature. In fact, we show that such price responsive loads are likely to induce peak-to-average ratios much more than what is observed in the current distribution networks and adversely affect the grid.

  8. Association of Childhood Economic Hardship with Adult Height and Adult Adiposity among Hispanics/Latinos. The HCHS/SOL Socio-Cultural Ancillary Study.

    Science.gov (United States)

    Isasi, Carmen R; Jung, Molly; Parrinello, Christina M; Kaplan, Robert C; Kim, Ryung; Crespo, Noe C; Gonzalez, Patricia; Gouskova, Natalia A; Penedo, Frank J; Perreira, Krista M; Perrino, Tatiana; Sotres-Alvarez, Daniela; Van Horn, Linda; Gallo, Linda C

    2016-01-01

    The study examined the association of childhood and current economic hardship with anthropometric indices in Hispanic/Latino adults, using data from the HCHS/SOL Socio-cultural ancillary study (N = 5,084), a community-based study of Hispanic/Latinos living in four urban areas (Bronx, NY, Chicago, IL, Miami, FL, and San Diego, CA). Childhood economic hardship was defined as having experienced a period of time when one's family had trouble paying for basic needs (e.g., food, housing), and when this economic hardship occurred: between 0-12, 13-18 years old, or throughout both of those times. Current economic hardship was defined as experiencing trouble paying for basic needs during the past 12 months. Anthropometry included height, body mass index (BMI), waist circumference (WC), and percentage body fat (%BF). Complex survey linear regression models were used to test the associations of childhood economic hardship with adult anthropometric indices, adjusting for potential confounders (e.g., age, sex, Hispanic background). Childhood economic hardship varied by Hispanic background, place of birth, and adult socio-economic status. Childhood economic hardship during both periods, childhood and adolescence, was associated with shorter height. Childhood economic hardship was associated with greater adiposity among US born individuals only. Current economic hardship was significantly associated with all three measures of adiposity (BMI, WC, %BF). These findings suggest that previous periods of childhood economic hardship appear to influence adult height more than adiposity, whereas current economic hardship may be a better determinant of adult adiposity in Hispanics.

  9. Cyclometalated Iridium(III) Complexes Containing 4,4'-π-Conjugated 2,2'-Bipyridine Derivatives as the Ancillary Ligands: Synthesis, Photophysics, and Computational Studies.

    Science.gov (United States)

    Sarma, Monima; Chatterjee, Tanmay; Bodapati, Ramakrishna; Krishnakanth, Katturi Naga; Hamad, Syed; Rao, S Venugopal; Das, Samar K

    2016-04-04

    This article demonstrates a series of cyclometalated Ir(III) complexes of the type [Ir(III)(C^N)2(N^N)](PF6), where C^N is 2-phenylpyridine, and N^N corresponds to the 4,4'-π-conjugated 2,2'-bipyridine ancillary ligands. All these compounds were synthesized through splitting of the binuclear dichloro-bridged complex precursor, [Ir(C^N)2(μ-Cl)]2, with the appropriate bipyridine ligands followed by the anion exchange reaction. The linear and nonlinear absorption properties of the synthesized complexes were investigated. The absorption spectra of all the title complexes exhibit a broad structureless feature in the spectral region of 350-700 nm with two bands being well-resolved in most of the cases. The structures of all the compounds were modeled in dichloromethane using the density functional theory (DFT) algorithm. The nature of electronic transitions was further comprehended on the basis of time-dependent DFT analysis, which indicates that the origins of various bands are primarily due to intraligand charge transfer transitions along with mixed-metal and ligand-centered transitions. The synthesized compounds are found to be nonemissive at room temperature because of probable nonradiative deactivation pathways of the T1 state that compete with the radiative (phosphorescence) decay modes. However, the frozen solutions of compounds Ir(MS 3) and Ir(MS 5) phosphoresce at the near-IR region, the other complexes remaining nonemissive up to 800 nm wavelength window. The two-photon absorption studies on the synthesized complexes reveal that values of the absorption cross-section are quite notable and lie in the range of 300-1000 GM in the picosecond case and 45-186 GM in the femtosecond case.

  10. Subunits of the Drosophila actin-capping protein heterodimer regulate each other at multiple levels.

    Directory of Open Access Journals (Sweden)

    Ana Rita Amândio

    Full Text Available The actin-Capping Protein heterodimer, composed of the α and β subunits, is a master F-actin regulator. In addition to its role in many cellular processes, Capping Protein acts as a main tumor suppressor module in Drosophila and in humans, in part, by restricting the activity of Yorkie/YAP/TAZ oncogenes. We aimed in this report to understand how both subunits regulate each other in vivo. We show that the levels and capping activities of both subunits must be tightly regulated to control F-actin levels and consequently growth of the Drosophila wing. Overexpressing capping protein α and β decreases both F-actin levels and tissue growth, while expressing forms of Capping Protein that have dominant negative effects on F-actin promote tissue growth. Both subunits regulate each other's protein levels. In addition, overexpressing one of the subunit in tissues knocked-down for the other increases the mRNA and protein levels of the subunit knocked-down and compensates for its loss. We propose that the ability of the α and β subunits to control each other's levels assures that a pool of functional heterodimer is produced in sufficient quantities to restrict the development of tumor but not in excess to sustain normal tissue growth.

  11. Subunits of the Drosophila actin-capping protein heterodimer regulate each other at multiple levels.

    Science.gov (United States)

    Amândio, Ana Rita; Gaspar, Pedro; Whited, Jessica L; Janody, Florence

    2014-01-01

    The actin-Capping Protein heterodimer, composed of the α and β subunits, is a master F-actin regulator. In addition to its role in many cellular processes, Capping Protein acts as a main tumor suppressor module in Drosophila and in humans, in part, by restricting the activity of Yorkie/YAP/TAZ oncogenes. We aimed in this report to understand how both subunits regulate each other in vivo. We show that the levels and capping activities of both subunits must be tightly regulated to control F-actin levels and consequently growth of the Drosophila wing. Overexpressing capping protein α and β decreases both F-actin levels and tissue growth, while expressing forms of Capping Protein that have dominant negative effects on F-actin promote tissue growth. Both subunits regulate each other's protein levels. In addition, overexpressing one of the subunit in tissues knocked-down for the other increases the mRNA and protein levels of the subunit knocked-down and compensates for its loss. We propose that the ability of the α and β subunits to control each other's levels assures that a pool of functional heterodimer is produced in sufficient quantities to restrict the development of tumor but not in excess to sustain normal tissue growth.

  12. Functional Diversification of Maize RNA Polymerase IV and V Subtypes via Alternative Catalytic Subunits

    Directory of Open Access Journals (Sweden)

    Jeremy R. Haag

    2014-10-01

    Full Text Available 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 analyses 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 subtypes 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.

  13. Insights into the subunit in-teractions of the chloroplast ATP synthase

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Subunit interactions of the chloroplast F0F1- ATP synthase were studied using the yeast two-hybrid system. The coding sequences of all the nine subunits of spinach chloroplast ATP synthase were cloned in two-hybrid vectors. The vectors were transformed into the yeast strains HF7c and SFY526 by various pairwise combinations, and the protein interactions were analyzed by measuring the yeast growth on minimal SD medium without serine, lucine and histidine. Interactions of γ Subunit with wild type or two truncated mutants of γ sununit, △εN21 and △εC45, which lose their abilities to inhibit the ATP hydrolysis, were also detected by in vitro and in vivo binding assay. The present results are largely accordant to the common structure model of F0F1-ATP synthase. Different from that in the E. Coli F0F1-ATP synthase, the δ subunit of chloroplast ATP syn- thase could interact with β,γ,ε and all the CF0 subunits in the two-hybrid system. These results suggested that though the chloroplast ATP synthase shares the similar structure and composition of subunits with the enzyme from E. Coli, it may be different in the subunit interactions and con- formational change during catalysis between these two sources of ATP synthase. Based on the present results and our knowledge of structure model of E. Coli ATP synthase, a deduced structure model of chloroplast ATP synthase was proposed.

  14. Role of subunit III and its lipids in the molecular mechanism of cytochrome c oxidase.

    Science.gov (United States)

    Sharma, Vivek; Ala-Vannesluoma, Pauliina; Vattulainen, Ilpo; Wikström, Mårten; Róg, Tomasz

    2015-08-01

    The terminal respiratory enzyme cytochrome c oxidase (CcO) reduces molecular oxygen to water, and pumps protons across the inner mitochondrial membrane, or the plasma membrane of bacteria. A two-subunit CcO harbors all the elements necessary for oxygen reduction and proton pumping. However, it rapidly undergoes turnover-induced irreversible damage, which is effectively prevented by the presence of subunit III and its tightly bound lipids. We have performed classical atomistic molecular dynamics (MD) simulations on a three-subunit CcO, which show the formation of water wires between the polar head groups of lipid molecules bound to subunit III and the proton uptake site Asp91 (Bos taurus enzyme numbering). Continuum electrostatic calculations suggest that these lipids directly influence the proton affinity of Asp91 by 1-2pK units. We surmise that lipids bound to subunit III influence the rate of proton uptake through the D-pathway, and therefore play a key role in preventing turnover-induced inactivation. Atomistic MD simulations show that subunit III is rapidly hydrated in the absence of internally bound lipids, which is likely to affect the rate of O2 diffusion into the active-site. The role of subunit III with its indigenous lipids in the molecular mechanism of CcO is discussed.

  15. Structural and spectroscopic studies of the native hemocyanin from Maia squinado and its structural subunits

    Science.gov (United States)

    Dolashka-Angelova, Pavlina; Hristova, Rumijana; Schuetz, Juergen; Stoeva, Stanka; Schwarz, Heinz; Voelter, Wolfgang

    2000-09-01

    The dodecameric hemocyanin of the crab Maia squinado contains five major electrophoretically separable polypeptide chains (structural subunits) which have been purified by FPLC ion exchange chromatography. The various proteins have been characterized by fluorescence spectroscopy, combined with fluorescence quenching studies, using acrylamide, caesium chloride and potassium iodide as tryptophan quenchers. The results show that the tryptophyl side chains of dodecameric Hc are deeply buried in hydrophobic regions of the hemocyanin aggregates and the quenching efficiency values for the native Hc in comparison with those from the constituent subunits are two to four times less. The conformational stabilities of the native dodecameric aggregate and its isolated structural subunits towards various denaturants (pH, temperature, guanidinium hydrochloride) indicate that the quaternary structure is stabilized by hydrophilic and polar forces, whereby, both, the oxy- and apo-forms of the protein have been considered. The critical temperatures for the structural subunits, Tc, determined by fluorescence spectroscopy, are in the region of 50-60°C, coinciding with the melting temperatures, Tm, determined by CD spectroscopy. The free energy of stabilization in water, Δ GDH 2O , toward guanidinium hydrochloride is about two times higher for the dodecamer as compared to the isolated subunits. These studies reveal that oligomerization between functional subunits has a stabilizing effect on the whole molecule and differences in the primary structures result in different stabilities of the subunits.

  16. Exact Length Distribution of Filamentous Structures Assembled from a Finite Pool of Subunits.

    Science.gov (United States)

    Harbage, David; Kondev, Jané

    2016-07-01

    Self-assembling filamentous structures made of protein subunits are ubiquitous in cell biology. These structures are often highly dynamic, with subunits in a continuous state of flux, binding to and falling off of filaments. In spite of this constant turnover of their molecular parts, many cellular structures seem to maintain a well-defined size over time, which is often required for their proper functioning. One widely discussed mechanism of size regulation involves the cell maintaining a finite pool of protein subunits available for assembly. This finite pool mechanism can control the length of a single filament by having assembly proceed until the pool of free subunits is depleted to the point when assembly and disassembly are balanced. Still, this leaves open the question of whether the same mechanism can provide size control for multiple filamentous structures that are assembled from a common pool of protein subunits, as is often the case in cells. We address this question by solving the steady-state master equation governing the stochastic assembly and disassembly of multifilament structures made from a shared finite pool of subunits. We find that, while the total number of subunits within a multifilament structure is well-defined, individual filaments within the structure have a wide, power-law distribution of lengths. We also compute the phase diagram for two multifilament structures competing for the same pool of subunits and identify conditions for coexistence when both have a well-defined size. These predictions can be tested in cell experiments in which the size of the subunit pool or the number of filament nucleators is tuned.

  17. An alternating GluN1-2-1-2 subunit arrangement in mature NMDA receptors.

    Directory of Open Access Journals (Sweden)

    Morgane Riou

    Full Text Available NMDA receptors (NMDARs form glutamate-gated ion channels that play a critical role in CNS physiology and pathology. Together with AMPA and kainate receptors, NMDARs are known to operate as tetrameric complexes with four membrane-embedded subunits associating to form a single central ion-conducting pore. While AMPA and some kainate receptors can function as homomers, NMDARs are obligatory heteromers composed of homologous but distinct subunits, most usually of the GluN1 and GluN2 types. A fundamental structural feature of NMDARs, that of the subunit arrangement around the ion pore, is still controversial. Thus, in a typical NMDAR associating two GluN1 and two GluN2 subunits, there is evidence for both alternating 1/2/1/2 and non-alternating 1/1/2/2 arrangements. Here, using a combination of electrophysiological and cross-linking experiments, we provide evidence that functional GluN1/GluN2A receptors adopt the 1/2/1/2 arrangement in which like subunits are diagonal to one another. Moreover, based on the recent crystal structure of an AMPA receptor, we show that in the agonist-binding and pore regions, the GluN1 subunits occupy a "proximal" position, closer to the central axis of the channel pore than that of GluN2 subunits. Finally, results obtained with reducing agents that differ in their membrane permeability indicate that immature (intracellular and functional (plasma-membrane inserted pools of NMDARs can adopt different subunit arrangements, thus stressing the importance of discriminating between the two receptor pools in assembly studies. Elucidating the quaternary arrangement of NMDARs helps to define the interface between the subunits and to understand the mechanism and pharmacology of these key signaling receptors.

  18. 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...

  19. Recent advances in the production of recombinant subunit vaccines in Pichia pastoris.

    Science.gov (United States)

    Wang, Man; Jiang, Shuai; Wang, Yefu

    2016-04-01

    Recombinant protein subunit vaccines are formulated using defined protein antigens that can be produced in heterologous expression systems. The methylotrophic yeast Pichia pastoris has become an important host system for the production of recombinant subunit vaccines. Although many basic elements of P. pastoris expression system are now well developed, there is still room for further optimization of protein production. Codon bias, gene dosage, endoplasmic reticulum protein folding and culture condition are important considerations for improved production of recombinant vaccine antigens. Here we comment on current advances in the application of P. pastoris for the synthesis of recombinant subunit vaccines.

  20. Stoichiometry of the Human Glycine Receptor Revealed by Direct Subunit counting

    Science.gov (United States)

    Durisic, Nela; Godin, Antoine G.; Wever, Claudia M.; Heyes, Colin D.; Lakadamyali, Melike; Dent, Joseph A.

    2012-01-01

    The subunit stoichiometry of heteromeric glycine-gated channels (GlyRs) determines fundamental properties of these key inhibitory neurotransmitter receptors; however the ratio of α1 to β-subunits per receptor remains controversial. We used single molecule imaging and stepwise photobleaching in Xenopus oocytes to directly determine the subunit stoichiometry of a glycine receptor to be 3α1:2β. This approach allowed us to determine the receptor stoichiometry in mixed populations consisting of both heteromeric and homomeric channels, additionally revealing the quantitative proportions for the two populations. PMID:22973015

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

    Science.gov (United States)

    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.

  2. Cereblon inhibits proteasome activity by binding to the 20S core proteasome subunit beta type 4.

    Science.gov (United States)

    Lee, Kwang Min; Lee, Jongwon; Park, Chul-Seung

    2012-10-26

    In humans, mutations in the gene encoding cereblon (CRBN) are associated with mental retardation. Although CRBN has been investigated in several cellular contexts, its function remains unclear. Here, we demonstrate that CRBN plays a role in regulating the ubiquitin-proteasome system (UPS). Heterologous expression of CRBN inhibited proteasome activity in a human neuroblastoma cell line. Furthermore, proteasome subunit beta type 4 (PSMB4), the β7 subunit of the 20S core complex, was identified as a direct binding partner of CRBN. These findings suggest that CRBN may modulate proteasome activity by directly interacting with the β7 subunit.

  3. Elongated polyproline motifs facilitate enamel evolution through matrix subunit compaction.

    Directory of Open Access Journals (Sweden)

    Tianquan Jin

    2009-12-01

    Full Text Available Vertebrate body designs rely on hydroxyapatite as the principal mineral component of relatively light-weight, articulated endoskeletons and sophisticated tooth-bearing jaws, facilitating rapid movement and efficient predation. Biological mineralization and skeletal growth are frequently accomplished through proteins containing polyproline repeat elements. Through their well-defined yet mobile and flexible structure polyproline-rich proteins control mineral shape and contribute many other biological functions including Alzheimer's amyloid aggregation and prolamine plant storage. In the present study we have hypothesized that polyproline repeat proteins exert their control over biological events such as mineral growth, plaque aggregation, or viscous adhesion by altering the length of their central repeat domain, resulting in dramatic changes in supramolecular assembly dimensions. In order to test our hypothesis, we have used the vertebrate mineralization protein amelogenin as an exemplar and determined the biological effect of the four-fold increased polyproline tandem repeat length in the amphibian/mammalian transition. To study the effect of polyproline repeat length on matrix assembly, protein structure, and apatite crystal growth, we have measured supramolecular assembly dimensions in various vertebrates using atomic force microscopy, tested the effect of protein assemblies on crystal growth by electron microscopy, generated a transgenic mouse model to examine the effect of an abbreviated polyproline sequence on crystal growth, and determined the structure of polyproline repeat elements using 3D NMR. Our study shows that an increase in PXX/PXQ tandem repeat motif length results (i in a compaction of protein matrix subunit dimensions, (ii reduced conformational variability, (iii an increase in polyproline II helices, and (iv promotion of apatite crystal length. Together, these findings establish a direct relationship between polyproline tandem

  4. P. berghei telomerase subunit TERT is essential for parasite survival.

    Science.gov (United States)

    Religa, Agnieszka A; Ramesar, Jai; Janse, Chris J; Scherf, Artur; Waters, Andrew P

    2014-01-01

    Telomeres define the ends of chromosomes protecting eukaryotic cells from chromosome instability and eventual cell death. The complex regulation of telomeres involves various proteins including telomerase, which is a specialized ribonucleoprotein responsible for telomere maintenance. Telomeres of chromosomes of malaria parasites are kept at a constant length during blood stage proliferation. The 7-bp telomere repeat sequence is universal across different Plasmodium species (GGGTTT/CA), though the average telomere length varies. The catalytic subunit of telomerase, telomerase reverse transcriptase (TERT), is present in all sequenced Plasmodium species and is approximately three times larger than other eukaryotic TERTs. The Plasmodium RNA component of TERT has recently been identified in silico. A strategy to delete the gene encoding TERT via double cross-over (DXO) homologous recombination was undertaken to study the telomerase function in P. berghei. Expression of both TERT and the RNA component (TR) in P. berghei blood stages was analysed by Western blotting and Northern analysis. Average telomere length was measured in several Plasmodium species using Telomere Restriction Fragment (TRF) analysis. TERT and TR were detected in blood stages and an average telomere length of ∼ 950 bp established. Deletion of the tert gene was performed using standard transfection methodologies and we show the presence of tert- mutants in the transfected parasite populations. Cloning of tert- mutants has been attempted multiple times without success. Thorough analysis of the transfected parasite populations and the parasite obtained from extensive parasite cloning from these populations provide evidence for a so called delayed death phenotype as observed in different organisms lacking TERT. The findings indicate that TERT is essential for P. berghei cell survival. The study extends our current knowledge on telomere biology in malaria parasites and validates further investigations to

  5. P. berghei telomerase subunit TERT is essential for parasite survival.

    Directory of Open Access Journals (Sweden)

    Agnieszka A Religa

    Full Text Available Telomeres define the ends of chromosomes protecting eukaryotic cells from chromosome instability and eventual cell death. The complex regulation of telomeres involves various proteins including telomerase, which is a specialized ribonucleoprotein responsible for telomere maintenance. Telomeres of chromosomes of malaria parasites are kept at a constant length during blood stage proliferation. The 7-bp telomere repeat sequence is universal across different Plasmodium species (GGGTTT/CA, though the average telomere length varies. The catalytic subunit of telomerase, telomerase reverse transcriptase (TERT, is present in all sequenced Plasmodium species and is approximately three times larger than other eukaryotic TERTs. The Plasmodium RNA component of TERT has recently been identified in silico. A strategy to delete the gene encoding TERT via double cross-over (DXO homologous recombination was undertaken to study the telomerase function in P. berghei. Expression of both TERT and the RNA component (TR in P. berghei blood stages was analysed by Western blotting and Northern analysis. Average telomere length was measured in several Plasmodium species using Telomere Restriction Fragment (TRF analysis. TERT and TR were detected in blood stages and an average telomere length of ∼ 950 bp established. Deletion of the tert gene was performed using standard transfection methodologies and we show the presence of tert- mutants in the transfected parasite populations. Cloning of tert- mutants has been attempted multiple times without success. Thorough analysis of the transfected parasite populations and the parasite obtained from extensive parasite cloning from these populations provide evidence for a so called delayed death phenotype as observed in different organisms lacking TERT. The findings indicate that TERT is essential for P. berghei cell survival. The study extends our current knowledge on telomere biology in malaria parasites and validates further

  6. Preclinical and clinical development of a dengue recombinant subunit vaccine.

    Science.gov (United States)

    Manoff, Susan B; George, Sarah L; Bett, Andrew J; Yelmene, Michele L; Dhanasekaran, Govindarajan; Eggemeyer, Linda; Sausser, Michele L; Dubey, Sheri A; Casimiro, Danilo R; Clements, David E; Martyak, Timothy; Pai, Vidya; Parks, D Elliot; Coller, Beth-Ann G

    2015-12-10

    This review focuses on a dengue virus (DENV) vaccine candidate based on a recombinant subunit approach which targets the DENV envelope glycoprotein (E). Truncated versions of E consisting of the N-terminal portion of E (DEN-80E) have been expressed recombinantly in the Drosophila S2 expression system and shown to have native-like conformation. Preclinical studies demonstrate that formulations containing tetravalent DEN-80E adjuvanted with ISCOMATRIX™ adjuvant induce high titer virus neutralizing antibodies and IFN-γ producing T cells in flavivirus-naïve non-human primates. The preclinical data further suggest that administration of such formulations on a 0, 1, 6 month schedule may result in higher maximum virus neutralizing antibody titers and better durability of those titers compared to administration on a 0, 1, 2 month schedule. In addition, the virus neutralizing antibody titers induced by adjuvanted tetravalent DEN-80E compare favorably to the titers induced by a tetravalent live virus comparator. Furthermore, DEN-80E was demonstrated to be able to boost virus neutralizing antibody titers in macaques that have had a prior DENV exposure. A monovalent version of the vaccine candidate, DEN1-80E, was formulated with Alhydrogel™ and studied in a proof-of-principle Phase I clinical trial by Hawaii Biotech, Inc. (NCT00936429). The clinical trial results demonstrate that both the 10 μg and 50 μg formulations of DEN1-80E with 1.25 mg of elemental aluminum were immunogenic when administered in a 3-injection series (0, 1, 2 months) to healthy, flavivirus-naïve adults. The vaccine formulations induced DENV-1 neutralizing antibodies in the majority of subjects, although the titers in most subjects were modest and waned over time. Both the 10 μg DEN1-80E and the 50 μg DEN1-80E formulations with Alhydrogel™ were generally well tolerated.

  7. Early diagnosis of sepsis using serum hemoglobin subunit Beta.

    Science.gov (United States)

    Yoo, Hayoung; Ku, Sae-Kwang; Kim, Shin-Woo; Bae, Jong-Sup

    2015-02-01

    The development of new sepsis-specific biomarkers is mandatory to improve the detection and monitoring of the disease. Hemoglobin is the main oxygen and carbon dioxide carrier in cells of the erythroid lineage and is responsible for oxygen delivery to the respiring tissues of the body. Hemoglobin subunit beta (HBβ) is a component of a larger protein called hemoglobin. The aim of this study was to evaluate blood levels of HBβ in septic patients. A prospective study of 82 patients with sepsis was conducted. Furthermore, C57BL/6 mice were subjected to cecal ligation and puncture (CLP) surgery. Alternatively, human umbilical vein endothelial cells (HUVECs) or C57BL/6 mice were exposed to lipopolysaccharide (LPS, 100 ng/ml to HUVECs or 10 mg/kg to mice). The data showed that LPS induced upregulation of the synthesis and secretion of HBβ in LPS-treated HUVECs and in LPS-injected and CLP mice. In patients admitted to the intensive care unit with sepsis, circulating levels of HBβ were significantly high (sepsis, 64.93-114.76 ng/ml, n = 30; severe sepsis, 157.37-268.69 ng/ml, n = 22; septic shock, 309.98-427.03 ng/ml, n = 30) when compared to the levels of control donors (9.76-12.28 ng/ml, n = 21). Patients with septic shock had higher HBβ levels when compared to patients with severe sepsis. Furthermore, the HBβ levels in septic patients were higher than those in healthy volunteers. These results suggest that in septic patients, HBβ blood level is related to the severity of sepsis and may represent a novel endothelial cell dysfunction marker. Moreover, HBβ can be used as a biomarker to determine the severity of sepsis.

  8. Genetic Analysis of the Mode of Interplay between an ATPase Subunit and Membrane Subunits of the Lipoprotein-Releasing ATP-Binding Cassette Transporter LolCDE†

    OpenAIRE

    Ito, Yasuko; Matsuzawa, Hitomi; Matsuyama, Shin-ichi; Narita, Shin-ichiro; Tokuda, Hajime

    2006-01-01

    The LolCDE complex, an ATP-binding cassette (ABC) transporter, releases lipoproteins from the inner membrane, thereby initiating lipoprotein sorting to the outer membrane of Escherichia coli. The LolCDE complex is composed of two copies of an ATPase subunit, LolD, and one copy each of integral membrane subunits LolC and LolE. LolD hydrolyzes ATP on the cytoplasmic side of the inner membrane, while LolC and/or LolE recognize and release lipoproteins anchored to the periplasmic leaflet of the i...

  9. Cyclic AMP-dependent protein kinase I: Cyclic nucleotide binding, structural changes, and release of the catalytic subunits

    OpenAIRE

    Smith, Stephen B.; White, Hillary D.; Siegel, Jeffrey B.; Krebs, Edwin G.

    1981-01-01

    Type I cyclic AMP (cAMP)-dependent protein kinase is composed of a dimeric regulatory subunit (R2) and two catalytic subunits (C subunits). The R2 dimer binds four cAMP molecules to release the two C subunits. To characterize the cAMP binding sites and elucidate their role in the release of the C subunits, the R2 dimer has been studied by equilibrium methods. The cAMP titration of R2 was monitored by endogenous tryptophan fluorescence, and the results suggest one class of binding sites. The t...

  10. 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...

  11. Rigidity of the subunit interfaces of the trimeric glutamate transporter GItT during translocation

    NARCIS (Netherlands)

    Groeneveld, Maarten; Slotboom, Dirk-Jan

    2007-01-01

    Glutamate transporters are trimeric membrane proteins in which each protomer contains a separate translocation path. To determine whether structural rearrangements take place at the subunit interfaces during transport, intersubunit disulfide bridges were introduced in the bacterial transporter GltT.

  12. 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.

  13. Distinct Subunit Domains Govern Synaptic Stability and Specificity of the Kainate Receptor

    Directory of Open Access Journals (Sweden)

    Christoph Straub

    2016-07-01

    Full Text Available Synaptic communication between neurons requires the precise localization of neurotransmitter receptors to the correct synapse type. Kainate-type glutamate receptors restrict synaptic localization that is determined by the afferent presynaptic connection. The mechanisms that govern this input-specific synaptic localization remain unclear. Here, we examine how subunit composition and specific subunit domains contribute to synaptic localization of kainate receptors. The cytoplasmic domain of the GluK2 low-affinity subunit stabilizes kainate receptors at synapses. In contrast, the extracellular domain of the GluK4/5 high-affinity subunit synergistically controls the synaptic specificity of kainate receptors through interaction with C1q-like proteins. Thus, the input-specific synaptic localization of the native kainate receptor complex involves two mechanisms that underlie specificity and stabilization of the receptor at synapses.

  14. Cooperative Subunit Refolding of a Light-Harvesting Protein through a Self-Chaperone Mechanism.

    Science.gov (United States)

    Laos, Alistair J; Dean, Jacob C; Toa, Zi S D; Wilk, Krystyna E; Scholes, Gregory D; Curmi, Paul M G; Thordarson, Pall

    2017-01-27

    The fold of a protein is encoded by its amino acid sequence, but how complex multimeric proteins fold and assemble into functional quaternary structures remains unclear. Here we show that two structurally different phycobiliproteins refold and reassemble in a cooperative manner from their unfolded polypeptide subunits, without biological chaperones. Refolding was confirmed by ultrafast broadband transient absorption and two-dimensional electronic spectroscopy to probe internal chromophores as a marker of quaternary structure. Our results demonstrate a cooperative, self-chaperone refolding mechanism, whereby the β-subunits independently refold, thereby templating the folding of the α-subunits, which then chaperone the assembly of the native complex, quantitatively returning all coherences. Our results indicate that subunit self-chaperoning is a robust mechanism for heteromeric protein folding and assembly that could also be applied in self-assembled synthetic hierarchical systems.

  15. AChR deficiency due to epsilon-subunit mutations : two common mutations in the Netherlands

    NARCIS (Netherlands)

    Faber, Catharina G.; Molenaar, Peter C.; Vles, Johannes S. H.; Bonifati, Domenic M.; Verschuuren, Jan J. G. M.; van Doorn, Pieter A.; Kuks, Jan B. M.; Wokke, John H. J.; Beeson, David; De Baets, Marc

    2009-01-01

    Congenital myasthenic syndromes are a clinically and genetically heterogeneous group of hereditary disorders affecting neuromuscular transmission. We have identified mutations within the acetylcholine receptor (AChR) epsilon-subunit gene underlying congenital myasthenic syndromes in nine patients (s

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

    Science.gov (United States)

    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.

  17. LEGO-NMR spectroscopy: a method to visualize individual subunits in large heteromeric complexes.

    Science.gov (United States)

    Mund, Markus; Overbeck, Jan H; Ullmann, Janina; Sprangers, Remco

    2013-10-18

    Seeing the big picture: Asymmetric macromolecular complexes that are NMR active in only a subset of their subunits can be prepared, thus decreasing NMR spectral complexity. For the hetero heptameric LSm1-7 and LSm2-8 rings NMR spectra of the individual subunits of the complete complex are obtained, showing a conserved RNA binding site. This LEGO-NMR technique makes large asymmetric complexes accessible to detailed NMR spectroscopic studies.

  18. Performance of information system implementation based on coupling-cohesion among subunits

    Institute of Scientific and Technical Information of China (English)

    Wang Tienan; Li Yijun; Wang Mingzhu

    2007-01-01

    The intermediate information system benefit and the coupling-cohesion of subunits are presented to study the performance of information system implementation. Based on the organizational information processing theory and the organizational behaviour theory, a theoretical model is established from the perspective of coupling-cohesion of subunits. The reliability and validity of the model are checked up with the structural equation models and the data collected with questionnaires. The results of the study give some theoretical and practical guidance.

  19. Phorbol-induced surface expression of NR2A subunit homologues in HEK293 cells

    Institute of Scientific and Technical Information of China (English)

    Chan-ying ZHENG; Xiu-juan YANG; Zhan-yan FU; Jian-hong LUO

    2006-01-01

    Aim: N-methyl-D-aspartate receptors (NMDAR) are heteromeric complexes primarily assembled from NR1 and NR2 subunits. In normal conditions, NR2 sub-units assemble into homodimers in the endoplasmic reticulum (ER). These homodimers remain in the ER until they coassemble with NR1 dimers and are trafficked to the cell surface. However, it still remains unclear whether functional homomeric NMDAR exist in physiological or pathological conditions. Methods: We transfected GFP-NR2A alone into HEK293 cells, treated the cells with PKC activator 12-myristate-13 acetate (PMA), and then detected surface NR2A sub-units with a live cell immunostaining method. We also used a series of NR2A mutants with a partial deletion of its C-terminus to identify the regions that are involved in the PMA-mediated surface expression of NR2A subunits. Results: NR2A subunits were expressed on the cell membrane after incubation with PMA (200 nmol/L,30 min), although no functional NMDA channels were detected after PMA-induced membrane trafficking. Immunostaining with an ER marker also revealed that NR2A subunits were exported from the ER after PMA treatment. Furthermore, the deletion of amino acids between 1149-1347 or 1354-1464 of NR2A inhibited PMA-induced surface expression of NR2A subunits. Conclusion: First, our data suggests that PMA treatment can induce the surface expression of homomeric NR2A subunits. Furthermore, this process is probably mediated by the NR2A C-terminal region between positions 1149 and 1464.

  20. Differential Distribution of Exosome Subunits at the Nuclear Lamina and in Cytoplasmic FociD⃞V⃞

    OpenAIRE

    Amy C Graham; Kiss, Daniel L.; Andrulis, Erik D.

    2006-01-01

    The exosome complex plays important roles in RNA processing and turnover. Despite significant mechanistic insight into exosome function, we still lack a basic understanding of the subcellular locales where exosome complex biogenesis and function occurs. Here, we employ a panel of Drosophila S2 stable cell lines expressing epitope-tagged exosome subunits to examine the subcellular distribution of exosome complex components. We show that tagged Drosophila exosome subunits incorporate into compl...

  1. Neutron Scattering and the 30 S Ribosomal Subunit of E. Coli

    Science.gov (United States)

    Moore, P. B.; Engelman, D. M.; Langer, J. A.; Ramakrishnan, V. R.; Schindler, D. G.; Schoenborn, B. P.; Sillers, I. Y.; Yabuki, S.

    1982-06-01

    This paper reviews the progress made in the study of the internal organization of the 30 S ribosomal subunit of E. coli by neutron scattering since 1975. A map of that particle showing the position of 14 of the subunit's 21 proteins is presented, and the methods currently used for collecting and analyzing such data are discussed. Also discussed is the possibility of extending the interpretation of neutron mapping data beyond the limits practical today.

  2. Significant prognostic values of nuclear genes encoding mitochondrial complex I subunits in tumor patients.

    Science.gov (United States)

    Li, L D; Sun, H F; Bai, Y; Gao, S P; Jiang, H L; Jin, W

    2016-01-01

    In cancer biology, it remains still open question concerning the oncogenic versus oncosuppressor behavior of metabolic genes, which includes those encoding mitochondrial complex I (CI) subunits. The prognostic value of nuclear genome mRNAs expression of CI subunits is to be evaluated in the tumor patients. We used the Kaplan Meier plotter database, the cBio Cancer Genomics Portal, and the Oncomine in which gene expression data and survival information were from thousands of tumor patients to assess the relevance of nuclear genome mRNAs level of CI subunits to patients' survival, as well as their alterations in gene and expression level in tumors. We presented that the relative expression level of overwhelming majority of the nuclear genes of CI subunits with survival significance (overall survival, relapse free survival, progression free survival, distant metastasis free survival, post progression survival, and first progression), had consistent effects for patients in each type of four tumors separately, including breast cancer, ovarian cancer, lung cancer, and gastric cancer. However, in gene level, frequent cumulative or individual alteration of these genes could not significantly affect patients' survival and the overexpression of the individual gene was not ubiquitous in tumors versus normal tissues. Given that reprogrammed energy metabolism was viewed as an emerging hallmark of tumor, thus tumor patients' survival might potentially to be evaluated by certain threshold for overall expression of CI subunits. Comprehensive understanding of the nuclear genome encoded CI subunits may have guiding significance for the diagnosis and prognosis in tumor patients.

  3. Proteasome (Prosome Subunit Variations during the Differentiation of Myeloid U937 Cells

    Directory of Open Access Journals (Sweden)

    Laurent Henry

    1997-01-01

    Full Text Available 20S proteasomes (prosomes/multicatalytic proteinase are protein particles built of 28 subunits in variable composition. We studied the changes in proteasome subunit composition during the differentiation of U937 cells induced by phorbol‐myristate‐acetate or retinoic acid plus 1,25‐dihydroxy‐cholecalciferol by western blot, flow cytometry and immuno‐fluorescence. p25K (C3, p27K (IOTA and p30/33K (C2 subunits were detected in both the nucleus and cytoplasm of undifferentiated cells. Flow cytometry demonstrated a biphasic decrease in proteasome subunits detection during differentiation induced by RA+VD. PMA caused an early transient decrease in these subunits followed by a return to their control level, except for p30/33K, which remained low. Immuno‐fluorescence also showed differences in the cytolocalization of the subunits, with a particular decrease in antigen labeling in the nucleus of RA+VD‐induced cells, and a scattering in the cytoplasm and a reorganization in the nucleus of PMA‐induced cells. Small amounts of proteasomal proteins were seen on the outer membrane of non‐induced cells; these membrane proteins disappeared when treated with RA+VD, whereas some increased on PMA‐induced cells. The differential changes in the distribution and type of proteasomes in RA+VD and PMA‐induced cells indicate that, possibly, 20S proteasomes may play a role in relation to the mechanisms of differentiation and the inducer used.

  4. Using yeast two-hybrid system to detect interactions of ATP synthase subunits from Spinacia oleracea

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Subunit interactions among the chloroplast ATP synthase subunits were studied using the yeast two-hybrid system. Various pairwise combinations of genes encoding a , b , g , d and e subunits of Spinach ATP synthase fused to the binding domain or activation domain of GAL4 DNA were introduced into yeast and then expression of a reporter gene encoding b -galactosidase was detected. Of all the combinations, that of g and e subunit genes showed the highest level of reporter gene expression, while those of a and b , a and e , b and e and b and d induced stable and significant reporter gene expression. The combination of d and e as well as that of d and g induced weak and unstable reporter gene expression. However, combinations of a and g , b and g and a and d did not induce reporter gene expression. These results suggested that specific and strong interactions between g and e , a and b , a and e , b and e and b and d subunits, and weak and transient interactions between d and e and d and g subunits occurred in the yeast cell in the two-hybrid system. These results give a new look into the structural change of ATP synthase during catalysis.

  5. Isolation and characterization of a new subunit of phycocyanin from Chroomonas placoidea

    Institute of Scientific and Technical Information of China (English)

    Yun Yun Zhang; Min Chen; Hong Cui

    2011-01-01

    A new phycocyanin (PC) fluorescent subunit named β2 (18 kDa) was isolated and characterized by both SDS-PAGE and isoelectric focusing (IEF) from a species of cryptophytic alga Chroomonas placoidea. PC was separated and purified by ammonium sulfate sedimentation followed by two steps of Sephadex G-100 chromatography. After denatured in 4 mol/L urea for 48 h, PC was divided into two fractions by passing through a Sephacryl S-100 chromatography column twice. The blue fraction (S-1) contained β subunits with a maximal absorbance at 595 nm in visible light region. While the green fraction (S-2) enriched in α subunits showed a characteristic long wavelength absorbance at 680-700 nm region and exhibited a relatively low molecular weight of 9.4 (α1) and 8.5 kDa (α2). Fraction S-1 also consisted of two different fluorescent subunits with molecular weight of 20.1 kDa (β1) and 18 kDa (β2) and differed from each other on isoelectric points of pH 5.7 (β1) and 6.0 (β2), respectively. Further investigation of peptide sequence will help a lot in elucidating the new subunit β2 that was smaller in size and more neutral than the known β1 subunit, and may provide an alternative explanation in structure of cryptophytic phycobiliproteins.

  6. Modulatory mechanisms and multiple functions of somatodendritic A-type K+ channel auxiliary subunits

    Directory of Open Access Journals (Sweden)

    Henry Hungtao Jerng

    2014-03-01

    Full Text Available Auxiliary subunits are non-conducting, modulatory components of the multi-protein ion channel complexes that underlie normal neuronal signaling. They interact with the pore-forming α-subunits to modulate surface distribution, ion conductance, and channel gating properties. For the somatodendritic subthreshold A-type potassium (ISA channel based on Kv4 α-subunits, two types of auxiliary subunits have been extensively studied: Kv channel-interacting proteins (KChIPs and dipeptidyl peptidase-like proteins (DPLPs. KChIPs are cytoplasmic calcium-binding proteins that interact with intracellular portions of the Kv4 subunits, whereas DPLPs are type II transmembrane proteins that associate with the Kv4 channel core. Both KChIPs and DPLPs genes contain multiple start sites that are used by various neuronal populations to drive the differential expression of functionally distinct N-terminal variants. In turn, these N-terminal variants generate tremendous functional diversity across the nervous system. Here, we focus our review on (1 the molecular mechanism underlying the unique properties of different N-terminal variants, (2 the shaping of native ISA properties by the concerted actions of KChIPs and DPLP variants, and (3 the surprising ways that KChIPs and DPLPs coordinate the activity of multiple channels to fine-tune neuronal excitability. Unlocking the unique contributions of different auxiliary subunit N-terminal variants may provide an important opportunity to develop novel targeted therapeutics to treat numerous neurological disorders.

  7. Using yeast two-hybrid system to detect interactions of ATP synthase subunits from Spinacia oleracea

    Institute of Scientific and Technical Information of China (English)

    石晓冰; 魏家绵; 沈允钢

    2000-01-01

    Subunit interactions among the chloroplast ATP synthase subunits were studied using the yeast two-hybrid system. Various pairwise combinations of genes encoding a, p, y, 8 and e subunits of Spinach ATP synthase fused to the binding domain or activation domain of GAL4 DNA were introduced into yeast and then expression of a reporter gene encoding p-galactosidase was detected. Of all the combinations, that of y and e subunit genes showed the highest level of reporter gene expression, while those of a and p, a and e, p and e and p and 8 induced stable and significant reporter gene expression. The combination of 8 and e as well as that of 8 and y induced weak and unstable reporter gene expression. However, combinations of a and y, p and y and a and 8 did not induce reporter gene expression. These results suggested that specific and strong interactions between y and e, a and p, a and e, p and e and p and 8 subunits, and weak and transient interactions between 8 and e and 8 and y subunits occurred in the yeast

  8. Molecular architecture of the yeast Elongator complex reveals an unexpected asymmetric subunit arrangement.

    Science.gov (United States)

    Setiaputra, Dheva T; Cheng, Derrick Th; Lu, Shan; Hansen, Jesse M; Dalwadi, Udit; Lam, Cindy Hy; To, Jeffrey L; Dong, Meng-Qiu; Yip, Calvin K

    2017-02-01

    Elongator is a ~850 kDa protein complex involved in multiple processes from transcription to tRNA modification. Conserved from yeast to humans, Elongator is assembled from two copies of six unique subunits (Elp1 to Elp6). Despite the wealth of structural data on the individual subunits, the overall architecture and subunit organization of the full Elongator and the molecular mechanisms of how it exerts its multiple activities remain unclear. Using single-particle electron microscopy (EM), we revealed that yeast Elongator adopts a bilobal architecture and an unexpected asymmetric subunit arrangement resulting from the hexameric Elp456 subassembly anchored to one of the two Elp123 lobes that form the structural scaffold. By integrating the EM data with available subunit crystal structures and restraints generated from cross-linking coupled to mass spectrometry, we constructed a multiscale molecular model that showed the two Elp3, the main catalytic subunit, are located in two distinct environments. This work provides the first structural insights into Elongator and a framework to understand the molecular basis of its multifunctionality.

  9. Identification of the fifth subunit of Saccharomyces cerevisiae replication factor C.

    Science.gov (United States)

    Gary, S L; Burgers, M J

    1995-01-01

    Yeast replication factor C (RF-C) is a multipolypeptide complex required for chromosomal DNA replication. Previously this complex was known to consist of at least four subunits. We here report the identification of a fifth RF-C subunit from Saccharomyces cerevisiae, encoded by the RFC5 (YBR0810) gene. This subunit exhibits highest homology to the 38 kDa subunit (38%) of human RF-C (activator 1). Like the other four RFC genes, the RFC5 gene is essential for yeast viability, indicating an essential function for each subunit. RFC5 mRNA is expressed at steady-state levels throughout the mitotic cell cycle. Upon overexpression in Escherichia coli Rfc5p has an apparent molecular mass of 41 kDa. Overproduction of RF-C activity in yeast is dependent on overexpression of the RFC5 gene together with overexpression of the RFC1-4 genes, indicating that the RFC5 gene product forms an integral subunit of this replication factor. Images PMID:8559655

  10. The 2.3 {angstrom} crystal structure of cholera toxin B subunit pentamer: Choleragenoid

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Rong-Guang; Westbrook, M.L. [Argonne National Lab., IL (United States); Maulik, P.R.; Reed, R.A.; Shipley, G. [Boston Univ., MA (United States). School of Medicine; Westbrook, E.M. [Argonne National Lab., IL (United States)]|[Northwestern Univ., Evanston, IL (United States); Scott, D.L.; Otwinowski, Z. [Yale Univ., New Haven, CT (United States)

    1996-02-01

    Cholera toxin, a heterohexameric AB{sub 5} enterotoxin released by Vibrio cholera, induces a profuse secretory diarrhea in susceptible hosts. Choleragenoid, the B subunit pentamer of cholera toxin, directs the enzymatic A subunit to its target by binding to GM{sub 1} gangliosides exposed on the luminal surface of intestinal epithelial cells. We have solved the crystal structure of choleragenoid at 2.3 {Angstrom} resolution by combining single isomorphous replacement with non-crystallographic symmetry averaging. The structure of the B subunits, and their pentameric arrangement, closely resembles that reported for the intact holotoxin (choleragen), the heat-labile enterotoxin from E. coli, and for a choleragenoid-GM{sub 1} pentasaccharide complex. In the absence of the A subunit the central cavity of the B pentamer is a highly solvated channel. The binding of the A subunit or the receptor pentasaccharide to choleragenoid has only a modest effect on the local stereochemistry and does not perceptibly alter the subunit interface.

  11. Early transcription factor subunits are encoded by vaccinia virus late genes.

    Science.gov (United States)

    Gershon, P D; Moss, B

    1990-06-01

    The vaccinia virus early transcription factor (VETF) was shown to be a virus-encoded heterodimer. The gene for the 82-kDa subunit was identified as open reading frame (ORF) A8L, based on the N-terminal sequence of factor purified by using DNA-affinity magnetic beads. The 70-kDa subunit of VETF was refractory to N-terminal analysis, and so N-terminal sequences were obtained for three internal tryptic peptides. All three peptides matched sequences within ORF D6R. ORFs A8L and D6R are located within the central region of the vaccinia virus genome and are separated by about 13,600 base pairs. Proteins corresponding to the 3' ends of ORFs A8L and D6R were overexpressed in Escherichia coli and used to prepare antisera that bound to the larger and smaller subunits, respectively, of affinity-purified VETF. Immunoblot analysis of proteins from infected cells indicated that both subunits are expressed exclusively in the late phase of infection, just prior to their packaging in virus particles. The two subunits of VETF have no significant local or overall amino acid sequence homology to one another, to other entries in biological sequence data bases including bacterial sigma factors, or to recently determined sequences of some eukaryotic transcription factors. The 70-kDa subunit, however, has motifs in common with a super-family of established and putative DNA and RNA helicases.

  12. Prehospital digital photography and automated image transmission in an emergency medical service – an ancillary retrospective analysis of a prospective controlled trial

    Directory of Open Access Journals (Sweden)

    Bergrath Sebastian

    2013-01-01

    Full Text Available Abstract Background Still picture transmission was performed using a telemedicine system in an Emergency Medical Service (EMS during a prospective, controlled trial. In this ancillary, retrospective study the quality and content of the transmitted pictures and the possible influences of this application on prehospital time requirements were investigated. Methods A digital camera was used with a telemedicine system enabling encrypted audio and data transmission between an ambulance and a remotely located physician. By default, images were compressed (jpeg, 640 x 480 pixels. On occasion, this compression was deactivated (3648 x 2736 pixels. Two independent investigators assessed all transmitted pictures according to predefined criteria. In cases of different ratings, a third investigator had final decision competence. Patient characteristics and time intervals were extracted from the EMS protocol sheets and dispatch centre reports. Results Overall 314 pictures (mean 2.77 ± 2.42 pictures/mission were transmitted during 113 missions (group 1. Pictures were not taken for 151 missions (group 2. Regarding picture quality, the content of 240 (76.4% pictures was clearly identifiable; 45 (14.3% pictures were considered “limited quality” and 29 (9.2% pictures were deemed “not useful” due to not/hardly identifiable content. For pictures with file compression (n = 84 missions and without (n = 17 missions, the content was clearly identifiable in 74% and 97% of the pictures, respectively (p = 0.003. Medical reports (n = 98, 32.8%, medication lists (n = 49, 16.4% and 12-lead ECGs (n = 28, 9.4% were most frequently photographed. The patient characteristics of group 1 vs. 2 were as follows: median age – 72.5 vs. 56.5 years, p = 0.001; frequency of acute coronary syndrome – 24/113 vs. 15/151, p = 0.014. The NACA scores and gender distribution were comparable. Median on-scene times were longer with picture

  13. 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.

  14. Atypical properties of a conventional calcium channel β subunit from the platyhelminth Schistosoma mansoni

    Directory of Open Access Journals (Sweden)

    Schneider Toni

    2008-03-01

    Full Text Available Abstract Background The function of voltage-gated calcium (Cav channels greatly depends on coupling to cytoplasmic accessory β subunits, which not only promote surface expression, but also modulate gating and kinetic properties of the α1 subunit. Schistosomes, parasitic platyhelminths that cause schistosomiasis, express two β subunit subtypes: a structurally conventional β subunit and a variant β subunit with unusual functional properties. We have previously characterized the functional properties of the variant Cavβ subunit. Here, we focus on the modulatory phenotype of the conventional Cavβ subunit (SmCavβ using the human Cav2.3 channel as the substrate for SmCavβ and the whole-cell patch-clamp technique. Results The conventional Schistosoma mansoni Cavβ subunit markedly increases Cav2.3 currents, slows macroscopic inactivation and shifts steady state inactivation in the hyperpolarizing direction. However, currents produced by Cav2.3 in the presence of SmCavβ run-down to approximately 75% of their initial amplitudes within two minutes of establishing the whole-cell configuration. This suppressive effect was independent of Ca2+, but dependent on intracellular Mg2+-ATP. Additional experiments revealed that SmCavβ lends the Cav2.3/SmCavβ complex sensitivity to Na+ ions. A mutant version of the Cavβ subunit lacking the first forty-six amino acids, including a string of twenty-two acidic residues, no longer conferred sensitivity to intracellular Mg2+-ATP and Na+ ions, while continuing to show wild type modulation of current amplitude and inactivation of Cav2.3. Conclusion The data presented in this article provide insights into novel mechanisms employed by platyhelminth Cavβ subunits to modulate voltage-gated Ca2+ currents that indicate interactions between the Ca2+ channel complex and chelated forms of ATP as well as Na+ ions. These results have potentially important implications for understanding previously unknown mechanisms by

  15. Differential distribution of G-protein beta-subunits in brain: an immunocytochemical analysis.

    Science.gov (United States)

    Brunk, I; Pahner, I; Maier, U; Jenner, B; Veh, R W; Nürnberg, B; Ahnert-Hilger, G

    1999-05-01

    Heterotrimeric G proteins play central roles in signal transduction of neurons and other cells. The variety of their alpha-, beta-, and gamma-subunits allows numerous combinations thereby confering specificity to receptor-G-protein-effector interactions. Using antisera against individual G-protein beta-subunits we here present a regional and subcellular distribution of Gbeta1, Gbeta2, and Gbeta5 in rat brain. Immunocytochemical specificity of the subtype-specific antisera is revealed in Sf9 cells infected with various G-protein beta-subunits. Since Gbeta-subunits together with a G-protein gamma-subunit affect signal cascades we include a distribution of the neuron-specific Ggamma2- and Ggamma3-subunits in selected brain areas. Gbeta1, Gbeta2, and Gbeta5 are preferentially distributed in the neuropil of hippocampus, cerebellum and spinal cord. Gbeta2 is highly concentrated in the mossy fibres of dentate gyrus neurons ending in the stratum lucidum of hippocampal CA3-area. High amounts of Gbeta2 also occur in interneurons innervating spinal cord alpha-motoneurons. Gbeta5 is differentially distributed in all brain areas studied. It is found in the pyramidal cells of hippocampal CA1-CA3 as well as in the granule cell layer of dentate gyrus and in some interneurons. In the spinal cord Gbeta5 in contrast to Gbeta2 concentrates around alpha-motoneurons. In cultivated mouse hippocampal and hypothalamic neurons Gbeta2 and Gbeta5 are found in different subcellular compartments. Whereas Gbeta5 is restricted to the perikarya, Gbeta2 is also found in processes and synaptic contacts where it partially colocalizes with the synaptic vesicle protein synaptobrevin. An antiserum recognizing Ggamma2 and Ggamma3 reveals that these subunits are less expressed in hippocampus and cerebellum. Presumably this antiserum specifically recognizes Ggamma2 and Ggamma3 in combinations with certain G alphas and/or Gbetas. The widespread but regionally and cellularly rather different distribution of

  16. 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

  17. Probing the Subunit-Subunit Interaction of the Tetramer of E. coli KDO8P Synthase by Electrospray Ionization Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    LI Zhili; SAU,Apurba Kumar

    2009-01-01

    Escherichia coli 3-Deoxy-D-manno-octulosonate 8-phosphate (KDO8P) synthase catalyzes the condensation reaction between D-arabinose 5-phosphate (A5P) and phosphoenolpyruvate (PEP) to form KDO8P and inorganic phosphate (Pi).This enzyme exists as a tetramer in solution, which is important for catalysis. Two different states of the enzyme were obtained: i) PEP-bound and ii) PEP-unbound. The effect of the substrates and products on the overall structure of KDO8P synthase in both PEP-bound and unbound states was examined using electrospray ioni-zation mass spectrometry. The analysis of our data showed that the complexes of the PEP-unbound enzyme with PEP (or P,) favored the formation of monomers, while the complexes with A5P (or KDO8P) mainly favored dimers. The PEP-bound enzyme was found to exist in the monomer and dimer with a small amount of the tetramer, whereas the PEP-unbound form primarily exists in the monomer and dimer, and no tetramer was observed, suggesting that the bound PEP have a role in stabilization of the tetrameric structure. Taken together, the results imply that the ad-dition of the substrates or products to the unbound enzyme may alter the subunit-subunit interactions and/or con-formational change of the protein at the active site, and this study also demonstrates that the electrospray ionization mass spectrometric method may be a powerful tool in probing the subunit-subunit interactions and/or conforma-tional change of multi-subunit protein upon binding to ligand.

  18. Design Method of Ancillary Material Supporting Roadway Influenced by Mining%采动影响巷道顶板辅助材料支护设计方法研究

    Institute of Scientific and Technical Information of China (English)

    贾后省; 赵希栋; 董阳阳; 白浪

    2013-01-01

    目前巷道辅助材料支护设计暂无具体的设计方法,主要以工程类比思想和设计者的工程经验指导设计,易造成辅助材料在巷道围岩性质较好区域支护过剩,围岩性质较差区域支护强度不足。针对此类问题,提出了合理的辅助材料支护参数应能保证支护后裸露岩层的尺寸小于巷道顶板表层岩层稳定跨距,同一条巷道中可根据顶板不同的表层岩层稳定跨距采用不同的辅助材料支护参数,并确定了采动影响条件下巷道顶板表层岩层稳定跨距的计算方法;同时将顶板表层岩层稳定跨距分成4类,给出了每类顶板的辅助材料选择原则,介绍了此种设计方法和原则在神东矿区补连塔12420回风巷和乌兰木伦矿12302回撤通道部分区域的应用情况。%At present , there is no design method of supporting roadway for ancillary material. It was designed by engineering analogy and experience , which would result in supporting excessively in area with good surrounding rock condition and supporting insufficiently in area with bad conditions.In order to solve this problem , it was put forward that rational ancillary material supporting parameters should make the dimension of non-supporting section was minor than stable caving pace of roof surface strata , and different ancillary material supporting parameters in same roadway were permitted according with different stable caving paces of roof surface strata .Cal-culation method of stable caving pace of roof surface strata influenced by mining was obtained .The stable caving paces of roof surface strata were classified into 4 classes, whose ancillary material selection principle was put forward.Application of this method in 12420 air-return roadway of Bulianta Colliery and 12302 dismantle roadway of Wulanmulun Colliery was introduced.

  19. Discovering the bacterial circular proteins : bacteriocins, cyanobactins, and pilins

    NARCIS (Netherlands)

    Montalban-Lopez, Manuel; Sanchez-Hidalgo, Marina; Cebrian, Ruben; Maqueda, Mercedes

    2012-01-01

    Over recent years, several examples of natural ribosomally synthesized circular proteins and peptides from diverse organisms have been described. They are a group of proteins for which the precursors must be post-translationally modified to join the N and C termini with a peptide bond. This feature

  20. Functional characterization of Kv channel beta-subunits from rat brain.

    Science.gov (United States)

    Heinemann, S H; Rettig, J; Graack, H R; Pongs, O

    1996-06-15

    1. The potassium channel beta-subunit from rat brain, Kv beta 1.1, is known to induce inactivation of the delayed rectifier channel Kv1.1 and Kv1.4 delta 1-110. 2. Kv beta 1.1 was co-expressed in Xenopus oocytes with various other potassium channel alpha-subunits. Kv beta 1.1 induced inactivation in members of the Kv1 subfamily with the exception of Kv 1.6; no inactivation of Kv 2.1, Kv 3.4 delta 2-28 and Kv4.1 channels could be observed. 3. The second member of the beta-subunit subfamily, Kv beta 2, had a shorter N-terminal end, accelerated inactivation of the A-type channel Kv 1.4, but did not induce inactivation when co-expressed with delayed rectifiers of the Kv1 channel family. 4. To test whether this subunit co-assembles with Kv alpha-subunits, the N-terminal inactivating domains of Kv beta 1.1 and Kv beta 3 were spliced to the N-terminus of Kv beta 2. The chimaeric beta-subunits (beta 1/ beta 2 and beta 3/ beta 2) induced fast inactivation of several Kv1 channels, indicating that Kv beta 2 associates with these alpha-subunits. No inactivation was induced in Kv 1.3, Kv 1.6, Kv2.1 and Kv3.4 delta 2-28 channels. 5. Kv beta 2 caused a voltage shift in the activation threshold of Kv1.5 of about -10 mV, indicating a putative physiological role. Kv beta 2 had a smaller effect on Kv 1.1 channels. 6. Kv beta 2 accelerated the activation time course of Kv1.5 but had no marked effect on channel deactivation.

  1. Distribution of Kv3.3 potassium channel subunits in distinct neuronal populations of mouse brain.

    Science.gov (United States)

    Chang, Su Ying; Zagha, Edward; Kwon, Elaine S; Ozaita, Andres; Bobik, Marketta; Martone, Maryann E; Ellisman, Mark H; Heintz, Nathaniel; Rudy, Bernardo

    2007-06-20

    Kv3.3 proteins are pore-forming subunits of voltage-dependent potassium channels, and mutations in the gene encoding for Kv3.3 have recently been linked to human disease, spinocerebellar ataxia 13, with cerebellar and extracerebellar symptoms. To understand better the functions of Kv3.3 subunits in brain, we developed highly specific antibodies to Kv3.3 and analyzed immunoreactivity throughout mouse brain. We found that Kv3.3 subunits are widely expressed, present in important forebrain structures but particularly prominent in brainstem and cerebellum. In forebrain and midbrain, Kv3.3 expression was often found colocalized with parvalbumin and other Kv3 subunits in inhibitory neurons. In brainstem, Kv3.3 was strongly expressed in auditory and other sensory nuclei. In cerebellar cortex, Kv3.3 expression was found in Purkinje and granule cells. Kv3.3 proteins were observed in axons, terminals, somas, and, unlike other Kv3 proteins, also in distal dendrites, although precise subcellular localization depended on cell type. For example, hippocampal dentate granule cells expressed Kv3.3 subunits specifically in their mossy fiber axons, whereas Purkinje cells of the cerebellar cortex strongly expressed Kv3.3 subunits in axons, somas, and proximal and distal, but not second- and third-order, dendrites. Expression in Purkinje cell dendrites was confirmed by immunoelectron microscopy. Kv3 channels have been demonstrated to rapidly repolarize action potentials and support high-frequency firing in various neuronal populations. In this study, we identified additional populations and subcellular compartments that are likely to sustain high-frequency firing because of the expression of Kv3.3 and other Kv3 subunits.

  2. Subunit sequences of the 4 x 6-mer hemocyanin from the golden orb-web spider, Nephila inaurata.

    Science.gov (United States)

    Averdam, Anne; Markl, Jürgen; Burmester, Thorsten

    2003-08-01

    The transport of oxygen in the hemolymph of many arthropod and mollusc species is mediated by large copper-proteins that are referred to as hemocyanins. Arthropod hemocyanins are composed of hexamers and oligomers of hexamers. Arachnid hemocyanins usually form 4 x 6-mers consisting of seven distinct subunit types (termed a-g), although in some spider taxa deviations from this standard scheme have been observed. Applying immunological and electrophoretic methods, six distinct hemocyanin subunits were identified in the red-legged golden orb-web spider Nephila inaurata madagascariensis (Araneae: Tetragnathidae). The complete cDNA sequences of six subunits were obtained that corresponded to a-, b-, d-, e-, f- and g-type subunits. No evidence for a c-type subunit was found in this species. The inclusion of the N. inaurata hemocyanins in a multiple alignment of the arthropod hemocyanins and the application of the Bayesian method of phylogenetic inference allow, for the first time, a solid reconstruction of the intramolecular evolution of the chelicerate hemocyanin subunits. The branch leading to subunit a diverged first, followed by the common branch of the dimer-forming b and c subunits, while subunits d and f, as well as subunits e and g form common branches. Assuming a clock-like evolution of the chelicerate hemocyanins, a timescale for the evolution of the Chelicerata was obtained that agrees with the fossil record.

  3. Structure of the Vibrio cholerae Type IVb Pilus and stability comparison with the Neisseria gonorrhoeae type IVa pilus.

    Science.gov (United States)

    Li, Juliana; Egelman, Edward H; Craig, Lisa

    2012-04-20

    Type IV pili are multifunctional filaments displayed on many bacterial pathogens. Members of the Type IVa pilus subclass are found on a diverse group of human pathogens, whereas Type IVb pili are found almost exclusively on enteric bacteria. The Type IVa and IVb subclasses are distinguished by differences in the pilin subunits, including the fold of the globular domain. To understand the implications of the distinct pilin folds, we compared the stabilities of pilin subunits and pilus filaments for the Type IVa GC pilus from Neisseria gonorrhoeae and the Type IVb toxin-coregulated pilus (TCP) from Vibrio cholerae. We show that while recombinant TCP pilin is more stable than GC pilin, the GC pili are more resistant to proteolysis, heat and chemical denaturation than TCP, remaining intact in 8 M urea. To understand these differences, we determined the TCP structure by electron microscopy and three-dimensional image reconstruction. TCP have an architecture similar to that of GC pili, with subunits arranged in a right-handed 1-start helix and related by an 8.4-Å axial rise and a 96.8° azimuthal rotation. However, the TCP subunits are not as tightly packed as GC pilins, and the distinct Type IVb pilin fold exposes a segment of the α-helical core of TCP. Hydrophobic interactions dominate for both pilus subtypes, but base stacking by aromatic residues conserved among the Type IVa pilins may contribute to GC pilus stability. The extraordinary stability of GC pili may represent an adaptation of the Type IVa pili to harsh environments and the need to retract against external forces.

  4. Archaeal type IV pili and their involvement in biofilm formation

    Directory of Open Access Journals (Sweden)

    Rianne eEsquivel

    2015-03-01

    Full Text Available Type IV pili are ancient proteinaceous structures present on the cell surface of species in nearly all bacterial and archaeal phyla. These filaments are involved in a diverse array of critical cellular processes. While the core components of the pilus biosynthesis machinery are highly conserved, type IV pilins, the structural subunits of pili, share little sequence homology. However, the conserved structure of the signal peptides of these pilus subunits has allowed the development of prediction programs that accurately detect the processing sites recognized by bacterial and archaeal prepilin peptidases. Using these programs, the genomes of organisms from both prokaryotic domains have been shown to encode a diverse set of putative type IV pilins. Recently, in vivo studies in model archaea representing the euryarchaeal and crenarchaeal kingdoms confirmed that several of these pilins are incorporated into type IV adhesion pili. In addition to facilitating surface adhesion, these in vivo studies also showed that several predicted pilins are required for additional functions that are critical to biofilm formation. Examples include the subunits of Sulfolobus acidocaldarius Ups pili, which are induced by exposure to UV light and promote cell aggregation and conjugation, and a subset of the Haloferax volcanii adhesion pilins, which play a critical role in microcolony formation while other pilins inhibit this process. The recent discovery of novel pilin functions such as the ability of haloarchaeal adhesion pilins to regulate swimming motility rather than being unique to organisms that inhabit high salt environments may point to novel prokaryotic regulatory pathways. In this review, we will discuss recent advances in our understanding of the functional roles played by archaeal type IV adhesion pili and their subunits, with particular emphasis on their involvement in biofilm formation.

  5. Comparison of Voltage Gated K(+) Currents in Arterial Myocytes with Heterologously Expressed K v Subunits.

    Science.gov (United States)

    Cox, Robert H; Fromme, Samantha

    2016-12-01

    We have shown that three components contribute to functional voltage gated K(+) (K v) currents in rat small mesenteric artery myocytes: (1) Kv1.2 plus Kv1.5 with Kvβ1.2 subunits, (2) Kv2.1 probably associated with Kv9.3 subunits, and (3) Kv7.4 subunits. To confirm and address subunit stoichiometry of the first two, we have compared the biophysical properties of K v currents in small mesenteric artery myocytes with those of Kv subunits heterologously expressed in HEK293 cells using whole cell voltage clamp methods. Selective inhibitors of Kv1 (correolide, COR) and Kv2 (stromatoxin, ScTx) channels were used to separate these K v current components. Conductance-voltage and steady state inactivation data along with time constants of activation, inactivation, and deactivation of native K v components were generally well represented by those of Kv1.2-1.5-β1.2 and Kv2.1-9.3 channels. The slope of the steady state inactivation-voltage curve (availability slope) proved to be the most sensitive measure of accessory subunit presence. The availability slope curves exhibited a single peak for both native K v components. Availability slope curves for Kv1.2-1.5-β1.2 and Kv2.1-9.3 channels expressed in human embryonic kidney cells also exhibited a single peak that shifted to more depolarized voltages with increasing accessory to α subunit transfection ratio. Availability slope curves for SxTc-insensitive currents were similar to those of Kv1.2-1.5 expressed with Kvβ1.2 at a 1:5 molar ratio while curves for COR-insensitive currents closely resembled those of Kv2.1 expressed with Kv9.3 at a 1:1 molar ratio. These results support the suggested Kv subunit combinations in small mesenteric artery, and further suggest that Kv1 α and Kvβ1.2 but not Kv2.1 and Kv9.3 subunits are present in a saturated (4:4) stoichiometry.

  6. Flexible subunit stoichiometry of functional human P2X2/3 heteromeric receptors.

    Science.gov (United States)

    Kowalski, Maria; Hausmann, Ralf; Schmid, Julia; Dopychai, Anke; Stephan, Gabriele; Tang, Yong; Schmalzing, Günther; Illes, Peter; Rubini, Patrizia

    2015-12-01

    The aim of the present work was to clarify whether heterotrimeric P2X2/3 receptors have a fixed subunit stoichiometry consisting of one P2X2 and two P2X3 subunits as previously suggested, or a flexible stoichiometry containing also the inverse subunit composition. For this purpose we transfected HEK293 cells with P2X2 and P2X3 encoding cDNA at the ratios of 1:2 and 4:1, and analysed the biophysical and pharmacological properties of the generated receptors by means of the whole-cell patch-clamp technique. The concentration-response curves for the selective agonist α,β-meATP did not differ from each other under the two transfection ratios. However, co-expression of an inactive P2X2 mutant and the wild type P2X3 subunit and vice versa resulted in characteristic distortions of the α,β-meATP concentration-response relationships, depending on which subunit was expressed in excess, suggesting that HEK293 cells express mixtures of (P2X2)1/(P2X3)2 and (P2X2)2/(P2X3)1 receptors. Whereas the allosteric modulators H+ and Zn2+ failed to discriminate between the two possible heterotrimeric receptor variants, the α,β-meATP-induced responses were blocked more potently by the competitive antagonist A317491, when the P2X2 subunit was expressed in deficit of the P2X3 subunit. Furthermore, blue-native PAGE analysis of P2X2 and P2X3 subunits co-expressed in Xenopus laevis oocytes and HEK293 cells revealed that plasma membrane-bound P2X2/3 receptors appeared in two clearly distinct heterotrimeric complexes: a (P2X2-GFP)2/(P2X3)1 complex and a (P2X2-GFP)1/(P2X3)2 complex. These data strongly indicate that the stoichiometry of the heteromeric P2X2/3 receptor is not fixed, but determined in a permutational manner by the relative availability of P2X2 and P2X3 subunits.

  7. Influence of Conformation of M. tuberculosis RNase P Protein Subunit on Its Function.

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    Alla Singh

    Full Text Available RNase P is an essential enzyme that processes 5' end leader sequence of pre-tRNA to generate mature tRNA. The bacterial RNase Ps contain a RNA subunit and one protein subunit, where the RNA subunit contains the catalytic activity. The protein subunit which lacks any catalytic activity, relaxes the ionic requirements for holoenzyme reaction and is indispensable for pre-tRNA cleavage in vivo. In the current study, we reconstituted the M. tuberculosis RNase P holoenzyme in vitro. We prepared the RNase P protein through two different strategies that differ in the conditions under which the recombinant M. tuberculosis protein, expressed in E. coli was purified. The mycobacterial RNase P protein which was purified under native conditions subsequent to isolation from inclusion bodies and in vitro renaturation, was capable of cleaving pre-tRNA specifically without the requirement of RNase P RNA. However, the preparation that was purified under denaturing conditions and refolded subsequently lacked any inherent pre-tRNA processing activity and cleaved the substrate only as a component of the holoenzyme with the RNA subunit. We found that the two RNase P protein preparations attained alternative conformations and differed with respect to their stability as well.

  8. Distinct Structural Pathways Coordinate the Activation of AMPA Receptor-Auxiliary Subunit Complexes.

    Science.gov (United States)

    Dawe, G Brent; Musgaard, Maria; Aurousseau, Mark R P; Nayeem, Naushaba; Green, Tim; Biggin, Philip C; Bowie, Derek

    2016-03-16

    Neurotransmitter-gated ion channels adopt different gating modes to fine-tune signaling at central synapses. At glutamatergic synapses, high and low activity of AMPA receptors (AMPARs) is observed when pore-forming subunits coassemble with or without auxiliary subunits, respectively. Whether a common structural pathway accounts for these different gating modes is unclear. Here, we identify two structural motifs that determine the time course of AMPAR channel activation. A network of electrostatic interactions at the apex of the AMPAR ligand-binding domain (LBD) is essential for gating by pore-forming subunits, whereas a conserved motif on the lower, D2 lobe of the LBD prolongs channel activity when auxiliary subunits are present. Accordingly, channel activity is almost entirely abolished by elimination of the electrostatic network but restored via auxiliary protein interactions at the D2 lobe. In summary, we propose that activation of native AMPAR complexes is coordinated by distinct structural pathways, favored by the association/dissociation of auxiliary subunits.

  9. Amyloid-β peptide binds to cytochrome C oxidase subunit 1.

    Science.gov (United States)

    Hernandez-Zimbron, Luis Fernando; Luna-Muñoz, Jose; Mena, Raul; Vazquez-Ramirez, Ricardo; Kubli-Garfias, Carlos; Cribbs, David H; Manoutcharian, Karen; Gevorkian, Goar

    2012-01-01

    Extracellular and intraneuronal accumulation of amyloid-beta aggregates has been demonstrated to be involved in the pathogenesis of Alzheimer's disease (AD). However, the precise mechanism of amyloid-beta neurotoxicity is not completely understood. Previous studies suggest that binding of amyloid-beta to a number of macromolecules has deleterious effects on cellular functions. Mitochondria were found to be the target for amyloid-beta, and mitochondrial dysfunction is well documented in AD. In the present study we have shown for the first time that Aβ 1-42 bound to a peptide comprising the amino-terminal region of cytochrome c oxidase subunit 1. Phage clone, selected after screening of a human brain cDNA library expressed on M13 phage and bearing a 61 amino acid fragment of cytochrome c oxidase subunit 1, bound to Aβ 1-42 in ELISA as well as to Aβ aggregates present in AD brain. Aβ 1-42 and cytochrome c oxidase subunit 1 co-immunoprecipitated from mitochondrial fraction of differentiated human neuroblastoma cells. Likewise, molecular dynamics simulation of the cytochrome c oxidase subunit 1 and the Aβ 1-42 peptide complex resulted in a reliable helix-helix interaction, supporting the experimental results. The interaction between Aβ 1-42 and cytochrome c oxidase subunit 1 may explain, in part, the diminished enzymatic activity of respiratory chain complex IV and subsequent neuronal metabolic dysfunction observed in AD.

  10. Molecular Characterization of Subunit G of the Vacuolar ATPase in Pathogen Dermatophyte Trichophyton rubrum

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    S Rezaie

    2006-06-01

    Full Text Available Trichophyton rubrum is an anthropophilic fungus causing up to 90% of chronic cases of dermatophytosis. Several properties of this fungus have been investigated so far. However, a few studies were carried out in the field of molecular biology of this fungus. In the present study, we tried to identify the subunit G of its vacuolar ATPase (V-ATPase. Pairs of 21 nt primers were designed from highly conserved regions of the V-ATPase subunit G genes in other fungi. Mentioned primers were utilized in PCR using isolated genomic DNA template as well as cytoplasmic RNA of T.rubrum and the PCR and RT-PCR fragments were then sequenced. About 469 nucleotides were sequenced which encoded a polypeptide with 119 amino acids. Nucleotide sequence comparison in gene data banks (NCBI, NIH for both the DNA and its deduced amino acid sequence revealed significant homology with V-ATPase subunit G genes and proteins of other eukaryotic cells. The amino acid sequence of the encoded protein was about 84% identical to the sequence of V-ATPase subunit G from other fungi. In summary, we have cloned the first V-ATPase subunit G of dermatophytes and characterized it as a member of this gene family in other eukaryotic cells.

  11. 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

  12. Cloning and Sequencing the y Subunit of R-Phycoerythrin from Corallina officinalis

    Institute of Scientific and Technical Information of China (English)

    WANGSheng; ZHONGFu-Di; WUZu-Jian; LINQi-Ying; XIELian-Hui

    2004-01-01

    The full-length cDNA of the γ subunit of R-phycoerythrin from Corallina officinalis L. was cloned by rapid amplification of cDNA ends (RACE) method, and sequenced. The full-length cDNA is a 2 308 bp consisting of 5' untranslated region (UTR) of 1 203 bp, an open reading frame (ORF) of 960 bp that encodes 320 amino acids, and 3' UTR of 145 bp. The mature γ polypeptide contains two unique internal repeat domains as reported by Apt et al. (2001). Sequence analysis of the different clones revealed different 3'-end sequences at the γ subunit. The difference between the 3'-end sequences suggests that the γ subunit may have more than one copy, or have gone through different post-transcriptional modification. By comparing the DNA and cDNA sequences, we found that the γ subunit is an intronless gene. This is thefirst report of the γ subunit gene of R-phycoerythrin from C. officinalis.

  13. The transcriptional coactivator SAYP is a trithorax group signature subunit of the PBAP chromatin remodeling complex.

    Science.gov (United States)

    Chalkley, Gillian E; Moshkin, Yuri M; Langenberg, Karin; Bezstarosti, Karel; Blastyak, Andras; Gyurkovics, Henrik; Demmers, Jeroen A A; Verrijzer, C Peter

    2008-05-01

    SWI/SNF ATP-dependent chromatin remodeling complexes (remodelers) perform critical functions in eukaryotic gene expression control. BAP and PBAP are the fly representatives of the two evolutionarily conserved major subclasses of SWI/SNF remodelers. Both complexes share seven core subunits, including the Brahma ATPase, but differ in a few signature subunits; POLYBROMO and BAP170 specify PBAP, whereas OSA defines BAP. Here, we show that the transcriptional coactivator and PHD finger protein SAYP is a novel PBAP subunit. Biochemical analysis established that SAYP is tightly associated with PBAP but absent from BAP. SAYP, POLYBROMO, and BAP170 display an intimately overlapping distribution on larval salivary gland polytene chromosomes. Genome-wide expression analysis revealed that SAYP is critical for PBAP-dependent transcription. SAYP is required for normal development and interacts genetically with core- and PBAP-selective subunits. Genetic analysis suggested that, like BAP, PBAP also counteracts Polycomb silencing. SAYP appears to be a key architectural component required for the integrity and association of the PBAP-specific module. We conclude that SAYP is a signature subunit that plays a major role in the functional specificity of the PBAP holoenzyme.

  14. Goniometer-based femtosecond X-ray diffraction of mutant 30S ribosomal subunit crystals

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    E. Han Dao

    2015-07-01

    Full Text Available In this work, we collected radiation-damage-free data from a set of cryo-cooled crystals for a novel 30S ribosomal subunit mutant using goniometer-based femtosecond crystallography. Crystal quality assessment for these samples was conducted at the X-ray Pump Probe end-station of the Linac Coherent Light Source (LCLS using recently introduced goniometer-based instrumentation. These 30S subunit crystals were genetically engineered to omit a 26-residue protein, Thx, which is present in the wild-type Thermus thermophilus 30S ribosomal subunit. We are primarily interested in elucidating the contribution of this ribosomal protein to the overall 30S subunit structure. To assess the viability of this study, femtosecond X-ray diffraction patterns from these crystals were recorded at the LCLS during a protein crystal screening beam time. During our data collection, we successfully observed diffraction from these difficult-to-grow 30S ribosomal subunit crystals. Most of our crystals were found to diffract to low resolution, while one crystal diffracted to 3.2 Å resolution. These data suggest the feasibility of pursuing high-resolution data collection as well as the need to improve sample preparation and handling in order to collect a complete radiation-damage-free data set using an X-ray Free Electron Laser.

  15. Strategies for the plant-based expression of dengue subunit vaccines.

    Science.gov (United States)

    Yap, Yun-Kiam; Smith, Duncan R

    2010-10-01

    Despite significant efforts in many countries, there is still no commercially viable dengue vaccine. Currently, attention is focused on the development of either live attenuated vaccines or live attenuated chimaeric vaccines using a variety of backbones. Alternate vaccine approaches, such as whole inactivated virus and subunit vaccines are in the early stages of development, and are each associated with different problems. Subunit vaccines offer the advantage of providing a uniform antigen of well-defined nature, without the added risk of introducing any genetic material into the person being inoculated. Preliminary trials of subunit vaccines (using dengue E protein) in rhesus monkeys have shown promising results. However, the primary disadvantages of dengue subunit vaccines are the low levels of expression of dengue proteins in mammalian or insect cells, as well as the added unknown risks of antigens produced from mammalian cells containing other potential sources of contamination. In the past two decades, plants have emerged as an alternative platform for expression of biopharmaceutical products, including antigens of bacterial, fungal or viral origin. In the present minireview, we highlight the current plant expression technologies used for expression of biopharmaceutical products, with an emphasis on plants as a production system for dengue subunit vaccines.

  16. Subunit movements in single membrane-bound H+-ATP synthases from chloroplasts during ATP synthesis.

    Science.gov (United States)

    Bienert, Roland; Rombach-Riegraf, Verena; Diez, Manuel; Gräber, Peter

    2009-12-25

    Subunit movements within the H(+)-ATP synthase from chloroplasts (CF(0)F(1)) are investigated during ATP synthesis. The gamma-subunit (gammaCys-322) is covalently labeled with a fluorescence donor (ATTO532). A fluorescence acceptor (adenosine 5'-(beta,gamma-imino)triphosphate (AMPPNP)-ATTO665) is noncovalently bound to a noncatalytic site at one alpha-subunit. The labeled CF(0)F(1) is integrated into liposomes, and a transmembrane pH difference is generated by an acid base transition. Single-pair fluorescence resonance energy transfer is measured in freely diffusing proteoliposomes with a confocal two-channel microscope. The fluorescence time traces reveal a repetitive three-step rotation of the gamma-subunit relative to the alpha-subunit during ATP synthesis. Some traces show splitting into sublevels with fluctuations between the sublevels. During catalysis the central stalk interacts, with equal probability, with each alphabeta-pair. Without catalysis the central stalk interacts with only one specific alphabeta-pair, and no stepping between FRET levels is observed. Two inactive states of the enzyme are identified: one in the presence of AMPPNP and one in the presence of ADP.

  17. Two Arabidopsis ADP-glucose pyrophosphorylase large subunits (APL1 and APL2) are catalytic.

    Science.gov (United States)

    Ventriglia, Tiziana; Kuhn, Misty L; Ruiz, Ma Teresa; Ribeiro-Pedro, Marina; Valverde, Federico; Ballicora, Miguel A; Preiss, Jack; Romero, José M

    2008-09-01

    ADP-glucose (Glc) pyrophosphorylase (ADP-Glc PPase) catalyzes the first committed step in starch biosynthesis. Higher plant ADP-Glc PPase is a heterotetramer (alpha(2)beta(2)) consisting of two small and two large subunits. There is increasing evidence that suggests that catalytic and regulatory properties of the enzyme from higher plants result from the synergy of both types of subunits. In Arabidopsis (Arabidopsis thaliana), two genes encode small subunits (APS1 and APS2) and four large subunits (APL1-APL4). Here, we show that in Arabidopsis, APL1 and APL2, besides their regulatory role, have catalytic activity. Heterotetramers formed by combinations of a noncatalytic APS1 and the four large subunits showed that APL1 and APL2 exhibited ADP-Glc PPase activity with distinctive sensitivities to the allosteric activator (3-phosphoglycerate). Mutation of the Glc-1-P binding site of Arabidopsis and potato (Solanum tuberosum) isoforms confirmed these observations. To determine the relevance of these activities in planta, a T-DNA mutant of APS1 (aps1) was characterized. aps1 is starchless, lacks ADP-Glc PPase activity, APS1 mRNA, and APS1 protein, and is late flowering in long days. Transgenic lines of the aps1 mutant, expressing an inactivated form of APS1, recovered the wild-type phenotype, indicating that APL1 and APL2 have catalytic activity and may contribute to ADP-Glc synthesis in planta.

  18. Two Arabidopsis ADP-Glucose Pyrophosphorylase Large Subunits (APL1 and APL2) Are Catalytic1

    Science.gov (United States)

    Ventriglia, Tiziana; Kuhn, Misty L.; Ruiz, Ma Teresa; Ribeiro-Pedro, Marina; Valverde, Federico; Ballicora, Miguel A.; Preiss, Jack; Romero, José M.

    2008-01-01

    ADP-glucose (Glc) pyrophosphorylase (ADP-Glc PPase) catalyzes the first committed step in starch biosynthesis. Higher plant ADP-Glc PPase is a heterotetramer (α2β2) consisting of two small and two large subunits. There is increasing evidence that suggests that catalytic and regulatory properties of the enzyme from higher plants result from the synergy of both types of subunits. In Arabidopsis (Arabidopsis thaliana), two genes encode small subunits (APS1 and APS2) and four large subunits (APL1–APL4). Here, we show that in Arabidopsis, APL1 and APL2, besides their regulatory role, have catalytic activity. Heterotetramers formed by combinations of a noncatalytic APS1 and the four large subunits showed that APL1 and APL2 exhibited ADP-Glc PPase activity with distinctive sensitivities to the allosteric activator (3-phosphoglycerate). Mutation of the Glc-1-P binding site of Arabidopsis and potato (Solanum tuberosum) isoforms confirmed these observations. To determine the relevance of these activities in planta, a T-DNA mutant of APS1 (aps1) was characterized. aps1 is starchless, lacks ADP-Glc PPase activity, APS1 mRNA, and APS1 protein, and is late flowering in long days. Transgenic lines of the aps1 mutant, expressing an inactivated form of APS1, recovered the wild-type phenotype, indicating that APL1 and APL2 have catalytic activity and may contribute to ADP-Glc synthesis in planta. PMID:18614708

  19. Mutations in the BLOC-1 Subunits Dysbindin and Muted Generate Divergent and Dosage-dependent Phenotypes*

    Science.gov (United States)

    Larimore, Jennifer; Zlatic, Stephanie A.; Gokhale, Avanti; Tornieri, Karine; Singleton, Kaela S.; Mullin, Ariana P.; Tang, Junxia; Talbot, Konrad; Faundez, Victor

    2014-01-01

    Post-mortem analysis has revealed reduced levels of the protein dysbindin in the brains of those suffering from the neurodevelopmental disorder schizophrenia. Consequently, mechanisms controlling the cellular levels of dysbindin and its interacting partners may participate in neurodevelopmental processes impaired in that disorder. To address this question, we studied loss of function mutations in the genes encoding dysbindin and its interacting BLOC-1 subunits. We focused on BLOC-1 mutants affecting synapse composition and function in addition to their established systemic pigmentation, hematological, and lung phenotypes. We tested phenotypic homogeneity and gene dosage effects in the mouse null alleles muted (Bloc1s5mu/mu) and dysbindin (Bloc1s8sdy/sdy). Transcripts of NMDA receptor subunits and GABAergic interneuron markers, as well as expression of BLOC-1 subunit gene products, were affected differently in the brains of Bloc1s5mu/mu and Bloc1s8sdy/sdy mice. Unlike Bloc1s8sdy/sdy, elimination of one or two copies of Bloc1s5 generated indistinguishable pallidin transcript phenotypes. We conclude that monogenic mutations abrogating the expression of a protein complex subunit differentially affect the expression of other complex transcripts and polypeptides as well as their downstream effectors. We propose that the genetic disruption of different subunits of protein complexes and combinations thereof diversifies phenotypic presentation of pathway deficiencies, contributing to the wide phenotypic spectrum and complexity of neurodevelopmental disorders. PMID:24713699

  20. Functional Analysis of a Wheat AGPase Plastidial Small Subunit with a Truncated Transit Peptide

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    Yang Yang

    2017-03-01

    Full Text Available ADP-glucose pyrophosphorylase (AGPase, the key enzyme in starch synthesis, consists of two small subunits and two large subunits with cytosolic and plastidial isoforms. In our previous study, a cDNA sequence encoding the plastidial small subunit (TaAGPS1b of AGPase in grains of bread wheat (Triticum aestivum L. was isolated and the protein subunit encoded by this gene was characterized as a truncated transit peptide (about 50% shorter than those of other plant AGPS1bs. In the present study, TaAGPS1b was fused with green fluorescent protein (GFP in rice protoplast cells, and confocal fluorescence microscopy observations revealed that like other AGPS1b containing the normal transit peptide, TaAGPS1b-GFP was localized in chloroplasts. TaAGPS1b was further overexpressed in a Chinese bread wheat cultivar, and the transgenic wheat lines exhibited a significant increase in endosperm AGPase activities, starch contents, and grain weights. These suggested that TaAGPS1b subunit was targeted into plastids by its truncated transit peptide and it could play an important role in starch synthesis in bread wheat grains.

  1. Expression of nicotinic acetylcholine receptor subunits from parasitic nematodes in Caenorhabditis elegans.

    Science.gov (United States)

    Sloan, Megan A; Reaves, Barbara J; Maclean, Mary J; Storey, Bob E; Wolstenholme, Adrian J

    2015-11-01

    The levamisole-sensitive nicotinic acetylcholine receptor present at nematode neuromuscular junctions is composed of multiple different subunits, with the exact composition varying between species. We tested the ability of two well-conserved nicotinic receptor subunits, UNC-38 and UNC-29, from Haemonchus contortus and Ascaris suum to rescue the levamisole-resistance and locomotion defects of Caenorhabditis elegans strains with null deletion mutations in the unc-38 and unc-29 genes. The parasite cDNAs were cloned downstream of the relevant C. elegans promoters and introduced into the mutant strains via biolistic transformation. The UNC-38 subunit of H. contortus was able to completely rescue both the locomotion defects and levamisole resistance of the null deletion mutant VC2937 (ok2896), but no C. elegans expressing the A. suum UNC-38 could be detected. The H. contortus UNC-29.1 subunit partially rescued the levamisole resistance of a C. elegans null mutation in unc-29 VC1944 (ok2450), but did cause increased motility in a thrashing assay. In contrast, only a single line of worms containing the A. suum UNC-29 subunit showed a partial rescue of levamisole resistance, with no effect on thrashing.

  2. Amyloid-β peptide binds to cytochrome C oxidase subunit 1.

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    Luis Fernando Hernandez-Zimbron

    Full Text Available Extracellular and intraneuronal accumulation of amyloid-beta aggregates has been demonstrated to be involved in the pathogenesis of Alzheimer's disease (AD. However, the precise mechanism of amyloid-beta neurotoxicity is not completely understood. Previous studies suggest that binding of amyloid-beta to a number of macromolecules has deleterious effects on cellular functions. Mitochondria were found to be the target for amyloid-beta, and mitochondrial dysfunction is well documented in AD. In the present study we have shown for the first time that Aβ 1-42 bound to a peptide comprising the amino-terminal region of cytochrome c oxidase subunit 1. Phage clone, selected after screening of a human brain cDNA library expressed on M13 phage and bearing a 61 amino acid fragment of cytochrome c oxidase subunit 1, bound to Aβ 1-42 in ELISA as well as to Aβ aggregates present in AD brain. Aβ 1-42 and cytochrome c oxidase subunit 1 co-immunoprecipitated from mitochondrial fraction of differentiated human neuroblastoma cells. Likewise, molecular dynamics simulation of the cytochrome c oxidase subunit 1 and the Aβ 1-42 peptide complex resulted in a reliable helix-helix interaction, supporting the experimental results. The interaction between Aβ 1-42 and cytochrome c oxidase subunit 1 may explain, in part, the diminished enzymatic activity of respiratory chain complex IV and subsequent neuronal metabolic dysfunction observed in AD.

  3. Expression of functional receptors by the human γ-aminobutyric acid A γ2 subunit

    Science.gov (United States)

    Martínez-Torres, Ataúlfo; Miledi, Ricardo

    2004-01-01

    γ-Aminobutyric acid A (GABAA) receptors are heteromeric membrane proteins formed mainly by various combinations of α, β, and γ subunits; and it is commonly thought that the γ2 subunit alone does not form functional receptors. In contrast, we found that cDNA encoding the γ2L subunit of the human GABAA receptor, injected alone into Xenopus oocytes, expressed functional GABA receptors whose properties were investigated by using the two-microelectrode voltage-clamp technique. GABA elicited desensitizing membrane currents that recovered after a few minutes' wash. Repetitive applications of GABA induced a “run-up” of GABA currents that nearly doubled the amplitude of the first response. The GABA currents inverted direction at about -30 mV, indicating that they are carried mainly by Cl- ions. The homomeric γ2L receptors were also activated by β-alanine > taurine > glycine, and, like some types of heteromeric GABAA receptors, the γ2L receptors were blocked by bicuculline and were potentiated by pentobarbital and flunitrazepam. These results indicate that the human γ2L subunit is capable of forming fully functional GABA receptors by itself in Xenopus oocytes and suggest that the roles proposed for the various subunits that make up the heteromeric GABAA receptors in situ require further clarification. PMID:14981251

  4. Inheritance of B subunits of glutenin and ω-and γ-gliadins in tetraploid wheats.

    Science.gov (United States)

    Liu, C Y; Shepherd, K W

    1995-06-01

    A double-1RS wheat-rye translocation line lacking all B subunits of glutenin was produced in durum wheat cv 'Langdon' for use in backcrosses and testcrosses in the study of the inheritance of low-molecular-weight (LMW) glutenin subunits in tetraploid wheats. The B subunits of glutenin and γ-and ω-gliadin bands present in parents derived from Triticum durum and T. dicoccoides, encoded by Glu-3 and Gli-1 loci, respectively, were found to be inherited mainly as units (blocks), as reported previously. Two rare recombination events between the Glu-A3 and Gli-A1 loci were detected in testcross progeny from 'Edmore' x T. dicoccoides landrace 19-27. Several rare recombinants were also detected within the 1BS-controlled B subunits of glutenin blocks, suggesting that there are two separate tightly linked loci (3.07±1.35 cM) within the Glu-B3 'locus'. Evidence was also obtained for the presence of an additional locus coding for a B subunit of glutenin in 'Edmore' that is loosely linked (20.9±3.18%) with the main Glu-B3 'locus'.

  5. Isolation and spectroscopic characterization of the structural subunits of keyhole limpet hemocyanin.

    Science.gov (United States)

    Schütz, J; Dolashka-Angelova, P; Abrashev, R; Nicolov, P; Voelter, W

    2001-04-07

    Keyhole limpet hemocyanin is a respiratory glycoprotein of high molecular weight from the gastropod mollusc Megathura crenulata. Two subunits, KLH1 and KLH2, were isolated using ion exchange chromatography and their physical properties are compared with the parent molecule. The various proteins are characterized by fluorescence spectroscopy, combined with fluorescence quenching studies, using acrylamide, cesium chloride and potassium iodide as tryptophan quenchers. The conformational stability of the native aggregate and its isolated structural subunits are also studied by circular dichroism and fluorescence spectroscopy as a function of temperature, as well as in the presence of guanidinium hydrochloride and urea. The associated subunits in the hemocyanin aggregates increase considerably the melting temperature to 67 degrees C and the free energy of stabilization in water, DeltaG(H(2)O)(D), towards guanidinium hydrochloride is higher for the decamer as compared to the isolated subunits; this difference can be accounted for by the stabilizing effects of intra-subunit interactions exerted within the oligomer. The copper-dioxygen complex at the active site additionally stabilizes the molecule, and removing of the copper ions increases the tryptophan emission and the quantum yield of the fluorescence.

  6. 3D structure prediction of replication factor C subunits (RFC and their interactome in Arabidopsis thaliana

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    Mohamed Ragab Abdel Gawwad

    2013-06-01

    Full Text Available DNA stress can causes potentially spontaneous genome damage during DNA replication process. Proteins involved in this process are DNA-dependent ATPases, required for replication and repair. In this study the 3-D structure of RFC protein subunits in Arabidopsis thaliana: RFC1, RFC2, RFC3, RFC4 and RFC5 are predicted and confirmed by Ramachadran plot. The amino acid sequences are highly similar to the sequences of the homologous human RFC 140-, 37-, 36-, 40-, and 38 kDa subunits, respectively, and also show amino acid sequence similarity to functionally homologous proteins from E. coli. All five subunits show conserved regions characteristic of ATP/GTP-binding proteins and have significant degree of similarity among each other. The segments of conserved amino acid sequences that define a family of related proteins have been identified. RFC1 is identical to CDC44, a gene identified as a cell division cycle gene encoding a protein involved in DNA metabolism. Subcellular localization and interactions of each protein RFC protein subunit is determined. It subsequently became clear that RFC proteins and their interactome have functions in cell cycle regulation and/or DNA replication and repair processes. In addition, AtRFC subunits are controlling the biosynthesis of salicylic and salicylic acid-mediated defense responses in Arabidopsis.

  7. Molecular basis of inherited calcium Channelopathies: role of mutations in pore-forming subunits

    Institute of Scientific and Technical Information of China (English)

    Lynn MCKEOWN; Philip ROBINSON; Owen T JONES

    2006-01-01

    The pore-forming alpha subunits of voltage-gated calcium channels contain the essential biophysical machinery that underlies calcium influx in response to cell depolarization.In combination with requisite auxiliary subunits,these pore subunits form calcium channel complexes that are pivotal to the physiology and pharmacology of diverse cells ranging from sperm to neurons.Not surprisingly,mutations in the pore subunits generate diverse pathologies,termed channelopathies,that range from failures in excitation-contraction coupling to night blindness.Over the last decade, major insights into the mechanisms of pathogenesis have been derived from animals showing spontaneous or induced mutations.In parallel,there has been considerable growth in our understanding of the workings of voltage-gated ion channels from a structure-function,regulation and cell biology perspective.Here we document our current understanding of the mutations underlying channelopathies involving the voltage-gated calcium channel alpha subunits in humans and other species.

  8. In Search of Small Molecule Inhibitors Targeting the Flexible CK2 Subunit Interface

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    Benoît Bestgen

    2017-02-01

    Full Text Available Protein kinase CK2 is a tetrameric holoenzyme composed of two catalytic (α and/or α’ subunits and two regulatory (β subunits. Crystallographic data paired with fluorescence imaging techniques have suggested that the formation of the CK2 holoenzyme complex within cells is a dynamic process. Although the monomeric CK2α subunit is endowed with a constitutive catalytic activity, many of the plethora of CK2 substrates are exclusively phosphorylated by the CK2 holoenzyme. This means that the spatial and high affinity interaction between CK2α and CK2β subunits is critically important and that its disruption may provide a powerful and selective way to block the phosphorylation of substrates requiring the presence of CK2β. In search of compounds inhibiting this critical protein–protein interaction, we previously designed an active cyclic peptide (Pc derived from the CK2β carboxy-terminal domain that can efficiently antagonize the CK2 subunit interaction. To understand the functional significance of this interaction, we generated cell-permeable versions of Pc, exploring its molecular mechanisms of action and the perturbations of the signaling pathways that it induces in intact cells. The identification of small molecules inhibitors of this critical interaction may represent the first-choice approach to manipulate CK2 in an unconventional way.

  9. Structural bases of oxygen-sensitivity in Fe(II) complexes with tripodal ligands. Steric effects, Lewis acidity and the role of ancillary ligands.

    Science.gov (United States)

    Benhamou, Laila; Thibon, Aurore; Brelot, Lydia; Lachkar, Mohammed; Mandon, Dominique

    2012-12-21

    of the ancillary ligands in all complexes. Comparative analysis of the structures reveals relatively invariant structural parameters within the series of Fe(SO(3)CF(3))(2) complexes, whereas FeCl(2) complexes display important metal to ligand elongations upon tripod substitution. The reactivity increase upon fluorination of the ligand in the FeCl(2) complexes is interpreted as resulting from sterically-induced pyridine flexibility. The opposite situation with Fe(SO(3)CF(3))(2) complexes is due to the lock of the coordination polyhedron in the absence of important steric stress, especially when the metal center becomes electron-deficient.

  10. Design of the Ancillary Equipment for Spent Fuel Transport of PWR Nuclear Power Plant%压水堆核电站乏燃料运输辅助设备设计

    Institute of Scientific and Technical Information of China (English)

    瓮松峰

    2012-01-01

    In order to load and unload spent fuel assemblies safely in NPP, the ancillary equipment for spent fuel transport used to perform fluid transfer activities such as water feeding, air charging, and cask drying and heat rejection. This paper introduces the requirements, the scheme and the principle of the ancillary equipment, which adopts centralized-control and modular design, and have the performances such as higher work efficiency, higher safety, less radioactive substance accumulation and friendly man-machine conversation.%乏燃料运输辅助设备是用于对乏燃料运输容器进行充水排气、充气排水、充气风干的设备,并可对已装载乏燃料组件的容器进行充水冷却,实现乏燃料组件的安全装卸.本文介绍乏燃料运输辅助设备的功能要求、设计方案和工作原理.设备采用模块化设计和集中控制,具有工作效率高、结构简单、安全性高、不易积聚放射性物质和人-机交互友好的特点.

  11. 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

    The highest CK2 activity was found in mouse testicles and brain, followed by spleen, liver, lung, kidney and heart. The activity values were directly correlated with the protein expression level of the CK2 subunits alpha (catalytic) and beta (regulatory). The alpha' subunit was only detected...... found for testicles and brain. The amount of CK2beta protein in brain in comparison to the other organs (except testicles) was estimated to be ca. 2-3-fold higher whereas the ratio of CK2beta between testicles and brain was estimated to be 3-4-fold. Results from the immunoprecipitation experiments...... support the notion for the existence of free CK2beta population and/or CK2beta in complex with other protein(s) present in brain and testicles. In all other mouse organs investigated, i.e. heart, lung, liver, kidney and spleen, no comparable amount of free CK2beta was observed. This is the first...

  12. 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.

  13. Splice variants of Na(V1.7 sodium channels have distinct β subunit-dependent biophysical properties.

    Directory of Open Access Journals (Sweden)

    Clare Farmer

    Full Text Available Genes encoding the α subunits of neuronal sodium channels have evolutionarily conserved sites of alternative splicing but no functional differences have been attributed to the splice variants. Here, using Na(V1.7 as an exemplar, we show that the sodium channel isoforms are functionally distinct when co-expressed with β subunits. The gene, SCN9A, encodes the α subunit of the Na(V1.7 channel, and contains both sites of alternative splicing that are highly conserved. In conditions where the intrinsic properties of the Na(V1.7 splice variants were similar when expressed alone, co-expression of β1 subunits had different effects on channel availability that were determined by splicing at either site in the α subunit. While the identity of exon 5 determined the degree to which β1 subunits altered voltage-dependence of activation (P = 0.027, the length of exon 11 regulated how far β1 subunits depolarised voltage-dependence of inactivation (P = 0.00012. The results could have a significant impact on channel availability, for example with the long version of exon 11, the co-expression of β1 subunits could lead to nearly twice as large an increase in channel availability compared to channels containing the short version. Our data suggest that splicing can change the way that Na(V channels interact with β subunits. Because splicing is conserved, its unexpected role in regulating the functional impact of β subunits may apply to multiple voltage-gated sodium channels, and the full repertoire of β subunit function may depend on splicing in α subunits.

  14. 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.

  15. Membrane-localized β-subunits alter the PIP2 regulation of high-voltage activated Ca2+ channels.

    Science.gov (United States)

    Suh, Byung-Chang; Kim, Dong-Il; Falkenburger, Björn H; Hille, Bertil

    2012-02-21

    The β-subunits of voltage-gated Ca(2+) (Ca(V)) channels regulate the functional expression and several biophysical properties of high-voltage-activated Ca(V) channels. We find that Ca(V) β-subunits also determine channel regulation by the membrane phospholipid phosphatidylinositol 4,5-bisphosphate (PIP(2)). When Ca(V)1.3, -2.1, or -2.2 channels are cotransfected with the β3-subunit, a cytosolic protein, they can be inhibited by activating a voltage-sensitive lipid phosphatase to deplete PIP(2). When these channels are coexpressed with a β2a-subunit, a palmitoylated peripheral membrane protein, the inhibition is much smaller. PIP(2) sensitivity could be increased by disabling the two palmitoylation sites in the β2a-subunit. To further test effects of membrane targeting of Ca(V) β-subunits on PIP(2) regulation, the N terminus of Lyn was ligated onto the cytosolic β3-subunit to confer lipidation. This chimera, like the Ca(V) β2a-subunit, displayed plasma membrane localization, slowed the inactivation of Ca(V)2.2 channels, and increased the current density. In addition, the Lyn-β3 subunit significantly decreased Ca(V) channel inhibition by PIP(2) depletion. Evidently lipidation and membrane anchoring of Ca(V) β-subunits compete with the PIP(2) regulation of high-voltage-activated Ca(V) channels. Compared with expression with Ca(V) β3-subunits alone, inhibition of Ca(V)2.2 channels by PIP(2) depletion could be significantly attenuated when β2a was coexpressed with β3. Our data suggest that the Ca(V) currents in neurons would be regulated by membrane PIP(2) to a degree that depends on their endogenous β-subunit combinations.

  16. 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.

  17. Progress in the development of subunit vaccines for gastrointestinal nematodes of ruminants.

    Science.gov (United States)

    Matthews, J B; Geldhof, P; Tzelos, T; Claerebout, E

    2016-12-01

    The global increase in anthelmintic resistant nematodes of ruminants, together with consumer concerns about chemicals in food, necessitates the development of alternative methods of control for these pathogens. Subunit recombinant vaccines are ideally placed to fill this gap. Indeed, they are probably the only valid option for the long-term control of ruminant parasitic nematodes given the increasing ubiquity of multidrug resistance in a range of worm species across the world. The development of a subunit multicellular parasite vaccine to the point of practical application would be a groundbreaking step in the control of these important endemic infections of livestock. This review summarizes the current status of subunit vaccine development for a number of important gastrointestinal nematodes of cattle and sheep, with a focus on the limitations and problems encountered thus far, and suggestions as to how these hurdles might be overcome.

  18. In Vitro Reassembly of Tobacco Ribulose-1,5-bisphosphate Carboxylase/ Oxygenase from Fully Denatured Subunits

    Institute of Scientific and Technical Information of China (English)

    Zhen-Hua YONG; Gen-Yun CHEN; Jiao-Nai SHI; Da-Quan XU

    2006-01-01

    It has been generally proved impossible to reassemble ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) from fully denatured subunits in vitro in higher plant, because large subunit of fully denatured Rubisco is liable to precipitate when the denaturant is removed by common methods of direct dilution and one-step dialysis. In our experiment, the problem of precipitation was resolved by an improved gradual dialysis method, which gradually decreased the concentration of denaturant. However, fully denatured Rubisco subunits still could not be reassembled into holoenzyme using gradual dialysis unless chaperonin 60was added. The restored activity of reassembled Rubisco was approximately 8% of natural enzyme. The quantity of reassembled Rubisco increased greatly when heat shock protein 70 was present in the reassembly process. ATP and Mg2+ were unnecessary for in vitro reassembly of Rubisco, and Mg2+ inhibited the reassembly process. The reassembly was weakened when ATP, Mg2+ and K+ existed together in the reassembly process.

  19. Recent advances in the development of subunit-based RSV vaccines.

    Science.gov (United States)

    Jaberolansar, Noushin; Toth, Istvan; Young, Paul R; Skwarczynski, Mariusz

    2016-01-01

    Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract infections causing pneumonia and bronchiolitis in infants. RSV also causes serious illness in elderly populations, immunocompromised patients and individuals with pulmonary or cardiac problems. The significant morbidity and mortality associated with RSV infection have prompted interest in RSV vaccine development. In the 1960s, a formalin-inactivated vaccine trial failed to protect children, and indeed enhanced pathology when naturally infected later with RSV. Hence, an alternative approach to traditional killed virus vaccines, which can induce protective immunity without serious adverse events, is desired. Several strategies have been explored in attempts to produce effective vaccine candidates including gene-based and subunit vaccines. Subunit-based vaccine approaches have shown promising efficacy in animal studies and several have reached clinical trials. The current stage of development of subunit-based vaccines against RSV is reviewed in this article.

  20. Model for growth hormone receptor activation based on subunit rotation within a receptor dimer

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Richard J.; Adams, Julian J.; Pelekanos, Rebecca A.; Wan, Yu; McKinstry, William J.; Palethorpe, Kathryn; Seeber, Ruth M.; Monks, Thea A.; Eidne, Karin A.; Parker, Michael W.; Waters, Michael J. (UWA); (St. Vincent); (Queensland)

    2010-07-13

    Growth hormone is believed to activate the growth hormone receptor (GHR) by dimerizing two identical receptor subunits, leading to activation of JAK2 kinase associated with the cytoplasmic domain. However, we have reported previously that dimerization alone is insufficient to activate full-length GHR. By comparing the crystal structure of the liganded and unliganded human GHR extracellular domain, we show here that there is no substantial change in its conformation on ligand binding. However, the receptor can be activated by rotation without ligand by inserting a defined number of alanine residues within the transmembrane domain. Fluorescence resonance energy transfer (FRET), bioluminescence resonance energy transfer (BRET) and coimmunoprecipitation studies suggest that receptor subunits undergo specific transmembrane interactions independent of hormone binding. We propose an activation mechanism involving a relative rotation of subunits within a dimeric receptor as a result of asymmetric placement of the receptor-binding sites on the ligand.

  1. Cox26 is a novel stoichiometric subunit of the yeast cytochrome c oxidase.

    Science.gov (United States)

    Levchenko, Maria; Wuttke, Jan-Moritz; Römpler, Katharina; Schmidt, Bernhard; Neifer, Klaus; Juris, Lisa; Wissel, Mirjam; Rehling, Peter; Deckers, Markus

    2016-07-01

    The cytochrome c oxidase (COX) is the terminal enzyme of the respiratory chain. The complex accepts electrons from cytochrome c and passes them onto molecular oxygen. This process contributes to energy capture in the form of a membrane potential across the inner membrane. The enzyme complex assembles in a stepwise process from the three mitochondria-encoded core subunits Cox1, Cox2 and Cox3, which associate with nuclear-encoded subunits and cofactors. In the yeast Saccharomyces cerevisiae, the cytochrome c oxidase associates with the bc1-complex into supercomplexes, allowing efficient energy transduction. Here we report on Cox26 as a protein found in respiratory chain supercomplexes containing cytochrome c oxidase. Our analyses reveal Cox26 as a novel stoichiometric structural subunit of the cytochrome c oxidase. A loss of Cox26 affects cytochrome c oxidase activity and respirasome organization.

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

    Science.gov (United States)

    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.

  3. [Topography of ribosomal proteins: reconsideration of of protein map of small ribosomal subunit].

    Science.gov (United States)

    Spirin, A S; Agafonov, D E; Kolb, V A; Kommer, A

    1996-11-01

    Exposure of proteins on the surface of the small (30S) ribosomal subunit of Escherichia coli was studied by the hot tritium bombardment technique. Eight of 21 proteins of the 30 S subunit (S3, S8, S10, S12, S15, S16, S17, and S19) had virtually no groups exposed on the surface of the particle, i.e., they were mainly hidden inside. Seven proteins (S1, S4, S5, S7, S18, S20, and S21) were all well exposed on the surface of the particle, thus being outside proteins. The remaining proteins (S2, S6, S9 and/or S11, S13, and S14) were partially exposed. On the basis of these results a reconcilement of the three-dimensional protein map of the small ribosomal subunit has been done and corrected model is proposed.

  4. Electrical remodeling of preoptic GABAergic neurons involves the Kv1.5 subunit.

    Directory of Open Access Journals (Sweden)

    Iustin V Tabarean

    Full Text Available The electrogenic machinery of an excitable cell can adapt in response to changes in input, genetic deficit or in pathological conditions, however the underlying molecular mechanisms are not understood. In cases of genetic deletion it is commonly observed that a channel subunit from the same family replaces the missing one. We have previously reported that Kv4.2-/- preoptic GABAergic neurons display identical firing characteristics to those of wild-type neurons despite having reduced A-type currents, and that, surprisingly, they present a robust upregulation of a delayed rectifier current, the nature of which is unknown. Here, using pharmacology, qPCR and Western blots we report that, although the wild-type neurons express several Kv subunits, the upregulated current is conducted by the Kv1.5 subunit exclusively. Thus, this study reveals the molecular nature of a novel mechanism of electrical remodeling in central neurons.

  5. [The role of ATPase subunits from E. coli in hydrogen-potassium exchange].

    Science.gov (United States)

    Martirosov, S M; Trchunian, A A

    1984-01-01

    A hypothesis was developed that in membranes of glycolysing bacteria functioned supercomplexes (F1 X F0-TrkA) and (F0-TrkA) which operated as H+-K+-pump exchanging 2H+ for one K+ and as H+-K+-antiport respectively. The mutants with defects in alpha, beta and gamma subunits of ATPase F1 manifested the alteration only in the work of (F1 X F0-TrkA). Defect in epsilon subunit of F1 broke the regulation of pump operation on the part of a cell turgor. In mutants with defects in F0 the changes in both supercomplexes were observed. The only mutation in unc- cluster producing the complete blocking of both systems operation was related to a defect in h3-subunit of F0 which was the dicyclohexylcarbodiimide-sensitive and apparently "gate" component of F0.

  6. 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...

  7. Crystal structure of ATP-binding subunit of an ABC transporter from Geobacillus kaustophilus.

    Science.gov (United States)

    Manjula, M; Pampa, K J; Kumar, S M; Mukherjee, S; Kunishima, N; Rangappa, K S; Lokanath, N K

    2015-03-27

    The ATP binding cassette (ABC) transporters, represent one of the largest superfamilies of primary transporters, which are very essential for various biological functions. The crystal structure of ATP-binding subunit of an ABC transporter from Geobacillus kaustophilus has been determined at 1.77 Å resolution. The crystal structure revealed that the protomer has two thick arms, (arm I and II), which resemble 'L' shape. The ATP-binding pocket is located close to the end of arm I. ATP molecule is docked into the active site of the protein. The dimeric crystal structure of ATP-binding subunit of ABC transporter from G. kaustophilus has been compared with the previously reported crystal structure of ATP-binding subunit of ABC transporter from Salmonella typhimurium.

  8. High resolution structure of the large ribosomal subunit from a Mesophilic Eubacterium

    Energy Technology Data Exchange (ETDEWEB)

    Harms, Joerg; Schluenzen, Frank; Zarivach, Raz; Bashan, Anat; Gat, Sharon; Agmon, Ilana; Bartels, Heike; Franceschi, Francois; Yonath, Ada (Weizmann Inst Israel); (Mac Planck Germany); (Max Planck Germany)

    2009-10-07

    We describe the high resolution structure of the large ribosomal subunit from Deinococcus radiodurans (D50S), a gram-positive mesophile suitable for binding of antibiotics and functionally relevant ligands. The over-all structure of D50S is similar to that from the archae bacterium Haloarcula marismortui (H50S); however, a detailed comparison revealed significant differences, for example, in the orientation of nucleotides in peptidyl transferase center and in the structures of many ribosomal proteins. Analysis of ribosomal features involved in dynamic aspects of protein biosynthesis that are partially or fully disordered in H50S revealed the conformations of intersubunit bridges in unbound subunits, suggesting how they may change upon subunit association and how movements of the L1-stalk may facilitate the exit of tRNA.

  9. Cloning and expression of the human N-methyl-D-aspartate receptor subunit NR3A

    DEFF Research Database (Denmark)

    Eriksson, Maria; Nilsson, Anna; Froelich-Fabre, Susanne

    2002-01-01

    Native N-methyl-D-aspartate (NMDA) receptors are heteromeric assemblies of four or five subunits. The NMDA receptor subunits, NR1, NR2A, NR2B, NR2C, and NR2D have been cloned in several species, including man. The NR3A subunit, which in rodents is predominantly expressed during early development......, seems to function by reducing the NMDA receptor response. The human homologue to the rat NR3A, however, had not been cloned. In order to study the functions of the human NR3A (hNR3A), we have cloned and sequenced the hNR3A. It was found to share 88% of the DNA sequence with the rat gene, corresponding...

  10. Α2 GABAA receptor sub-units in the ventral hippocampus and α5 GABAA receptor sub-units in the dorsal hippocampus mediate anxiety and fear memory.

    Science.gov (United States)

    McEown, K; Treit, D

    2013-11-12

    Temporary neuronal inactivation of the ventral hippocampus with the GABAA agonist muscimol suppresses unconditioned fear behavior (anxiety) but inactivation of the dorsal hippocampus does not. On the other hand, inactivating the dorsal hippocampus disrupts fear memory, while inactivating the ventral hippocampus does not. Here we investigate the roles of hippocampal GABAA receptor sub-units in mediating these anxiolytic and amnesic effects of GABAA receptor agonists. We microinfused TPA023 (α2 agonist) or TB-21007 (inverse α5 agonist) into the dorsal or ventral hippocampus prior to testing rats in two animal models of anxiety: the elevated plus-maze and shock-probe burying test. Twenty-four hours later rats were re-tested in the shock-probe chamber with a non-electrified probe to assess their memory of the initial shock-probe experience (i.e., fear memory). We found that TPA023 was anxiolytic in the plus-maze and shock-probe burying tests when microinfused into the ventral hippocampus. However, TPA023 did not affect anxiety-related behavior when infused into the dorsal hippocampus. Conversely, we found that the α5 sub-unit inverse agonist TB-21007 impaired rats' memory of the initial shock-probe experience when infused into the dorsal hippocampus, but not when infused into the ventral hippocampus. This double dissociation suggests that α2 GABAA receptor sub-units in the ventral hippocampus mediate unconditioned fear or anxiety, while α5 GABAA receptor sub-units in the dorsal hippocampus mediate conditioned fear memory.

  11. Assembly of ROMK1 (Kir 1.1a) inward rectifier K+ channel subunits involves multiple interaction sites.

    Science.gov (United States)

    Koster, J C; Bentle, K A; Nichols, C G; Ho, K

    1998-04-01

    The ROMK1 (Kir 1.1a) channel is formed by a tetrameric complex of subunits, each characterized by cytoplasmic N- and C-termini and a core region of two transmembrane helices flanking a pore-forming segment. To delineate the general regions mediating the assembly of ROMK1 subunits we constructed epitope-tagged N-terminal, C-terminal, and transmembrane segment deletion mutants. Nonfunctional subunits with N-terminal, core region, and C-terminal deletions had dominant negative effects when coexpressed with wild-type ROMK1 subunits in Xenopus oocytes. In contrast, coexpression of these nonfunctional subunits with Kv 2.1 (DRK1) did not suppress Kv 2.1 currents in control oocytes. Interactions between epitope-tagged mutant and wild-type ROMK1 subunits were studied in parallel by immunoprecipitating [35S]-labeled oocyte membrane proteins. Complexes containing both wild-type and mutant subunits that retained H5, M2, and C-terminal regions were coimmunoprecipitated to a greater extent than complexes consisting of wild-type and mutant subunits with core region and/or C-terminal deletions. The present findings are consistent with the hypothesis that multiple interaction sites located in the core region and cytoplasmic termini of ROMK1 subunits mediate homomultimeric assembly.

  12. The mitochondrial respiratory chain of the secondary green alga Euglena gracilis shares many additional subunits with parasitic Trypanosomatidae.

    Science.gov (United States)

    Perez, Emilie; Lapaille, Marie; Degand, Hervé; Cilibrasi, Laura; Villavicencio-Queijeiro, Alexa; Morsomme, Pierre; González-Halphen, Diego; Field, Mark C; Remacle, Claire; Baurain, Denis; Cardol, Pierre

    2014-11-01

    The mitochondrion is an essential organelle for the production of cellular ATP in most eukaryotic cells. It is extensively studied, including in parasitic organisms such as trypanosomes, as a potential therapeutic target. Recently, numerous additional subunits of the respiratory-chain complexes have been described in Trypanosoma brucei and Trypanosoma cruzi. Since these subunits had apparently no counterparts in other organisms, they were interpreted as potentially associated with the parasitic trypanosome lifestyle. Here we used two complementary approaches to characterise the subunit composition of respiratory complexes in Euglena gracilis, a non-parasitic secondary green alga related to trypanosomes. First, we developed a phylogenetic pipeline aimed at mining sequence databases for identifying homologues to known respiratory-complex subunits with high confidence. Second, we used MS/MS proteomics after two-dimensional separation of the respiratory complexes by Blue Native- and SDS-PAGE both to confirm in silico predictions and to identify further additional subunits. Altogether, we identified 41 subunits that are restricted to E. gracilis, T. brucei and T. cruzi, along with 48 classical subunits described in other eukaryotes (i.e. plants, mammals and fungi). This moreover demonstrates that at least half of the subunits recently reported in T. brucei and T. cruzi are actually not specific to Trypanosomatidae, but extend at least to other Euglenozoa, and that their origin and function are thus not specifically associated with the parasitic lifestyle. Furthermore, preliminary biochemical analyses suggest that some of these additional subunits underlie the peculiarities of the respiratory chain observed in Euglenozoa.

  13. Cloning, Expression and Purification of Subunit H of Vacuolar H+-ATPase from Mythimna separata Walker (Lepidoptera: Noctuidae

    Directory of Open Access Journals (Sweden)

    Lina Lu

    2014-09-01

    Full Text Available The vacuolar (H+-ATPase (V-ATPase of insect, which is composed of membrane-bound V0 complex and peripheral V1 complex, participates in lots of important physiological process. Subunit H, as a subunit of V1 complex, plays a vital role in bridging the communication between V1 and V0 complexes and interaction with other proteins. Yeast subunit H has been successfully crystallized through expression in E. coli, but little is known about the structure of insect subunit H. In this study, we cloned, expressed and purified the subunit H from midgut of Mythimna separata Walker. Through RACE (rapidly amplification of cDNA ends technique, we got 1807 bp full length of subunit H, and to keep the nature structure of subunit H, we constructed Baculovirus expression vector with His-tag in the C-terminal and expressed the recombinant protein in insect sf9 cells, thereafter, purified the recombinant protein by Ni-NTA columns. Results of SDS-PAGE, western blotting and mass spectrometry showed that the recombinant protein was successfully expressed. The method of expressing and purifying M. separata subunit H will provide a foundation for obtaining the crystal of subunit H and further study of the design of novel insecticides based on its structure and function.

  14. Interaction of the regulatory and catalytic subunits of cAMP-dependent protein kinase. Electrostatic sites on the type Ialpha regulatory subunit.

    Science.gov (United States)

    Gibson, R M; Ji-Buechler, Y; Taylor, S S

    1997-06-27

    Since a basic surface on the catalytic (C) subunit of cAMP-dependent protein kinase is important for binding to the regulatory (R) subunit, acidic residues in R were sought that might contribute to R-C interaction. Using differential labeling by a water-soluble carbodiimide (Buechler, T. A., and Taylor, S. S. (1990) Biochemistry 29, 1937-1943), seven specific carboxylates in RIalpha were identified that were protected from chemical modification in the holoenzyme; each was then replaced with Ala. Of these, rRI(E15A/E106A/D107A)), rRI(E105A), rRI(D140A), rRI(E143A), and rRI(D258A) all were defective in holoenzyme formation and define negative electrostatic surfaces on RIalpha. An additional conserved carboxylate, Glu101 in RIalpha and the equivalent, Glu99 in RIIalpha were mutated to Ala. Replacement of Glu101 had no effect while rRII(E99A) was very defective. RIalpha and RIIalpha thus differ in the molecular details of how they recognize C. Unlike wild-type RI, two additional mutants, rRI(D170A) and rRI(K242A), inhibited C-subunit stoichiometrically in the presence of cAMP and show increases in both on- and off-rates. Asp170, which contributes directly to the hydrogen bonding network in cAMP-binding site A, thus contributes also to holoenzyme stability.

  15. Molecular cloning and expression of a GABA receptor subunit from the crayfish Procambarus clarkii.

    Science.gov (United States)

    Jiménez-Vázquez, Eric N; Díaz-Velásquez, Clara E; Uribe, R M; Arias, Juan M; García, Ubaldo

    2016-02-01

    Molecular cloning has introduced an unexpected, large diversity of neurotransmitter hetero- oligomeric receptors. Extensive research on the molecular structure of the γ-aminobutyric acid receptor (GABAR) has been of great significance for understanding how the nervous system works in both vertebrates and invertebrates. However, only two examples of functional homo-oligomeric GABA-activated Cl(-) channels have been reported. In the vertebrate retina, the GABAρ1 subunit of various species forms homo-oligomeric receptors; in invertebrates, a cDNA encoding a functional GABA-activated Cl(-) channel has been isolated from a Drosophila melanogaster head cDNA library. When expressed in Xenopus laevis oocytes, these subunits function efficiently as a homo-oligomeric complex. To investigate the structure-function of GABA channels from the crayfish Procambarus clarkii, we cloned a subunit and expressed it in human embryonic kidney cells. Electrophysiological recordings show that this subunit forms a homo-oligomeric ionotropic GABAR that gates a bicuculline-insensitive Cl(-) current. The order of potency of the agonists was GABA > trans-4-amino-crotonic acid = cis-4-aminocrotonic acid > muscimol. These data support the notion that X-organ sinus gland neurons express at least two GABA subunits responsible for the formation of hetero-oligomeric and homo-oligomeric receptors. In addition, by in situ hybridization studies we demonstrate that most X-organ neurons from crayfish eyestalk express the isolated pcGABAA β subunit. This study increases the knowledge of the genetics of the crayfish, furthers the understanding of this important neurotransmitter receptor family, and provides insight into the evolution of these genes among vertebrates and invertebrates.

  16. Crucial role of nicotinic α5 subunit variants for Ca2+ fluxes in ventral midbrain neurons.

    Science.gov (United States)

    Sciaccaluga, Miriam; Moriconi, Claudia; Martinello, Katiuscia; Catalano, Myriam; Bermudez, Isabel; Stitzel, Jerry A; Maskos, Uwe; Fucile, Sergio

    2015-08-01

    Neuronal nicotinic acetylcholine receptors (nAChRs) containing the α5 subunit modulate nicotine consumption, and the human CHRNA5 rs16969968 polymorphism, causing the replacement of the aspartic acid residue at position 398 with an asparagine (α5DN), has recently been associated with increased use of tobacco and higher incidence of lung cancer. We show that in ventral midbrain neurons, the α5 subunit is essential for heteromeric nAChR-induced intracellular-free Ca(2+) concentration elevations and that in α5(-/-) mice, a class of large-amplitude nicotine-evoked currents is lost. Furthermore, the expression of the α5DN subunit is not able to restore nicotinic responses, indicating a loss of function by this subunit in native neurons. To understand how α5DN impairs heteromeric nAChR functions, we coexpressed α4, α5, or α5DN subunits with a dimeric concatemer (β2α4) in a heterologous system, to obtain nAChRs with fixed stoichiometry. Both α5(β2α4)2 and α5DN(β2α4)2 nAChRs yielded similar levels of functional expression and Ca(2+) permeability, measured as fractional Ca(2+) currents (8.2 ± 0.7% and 8.0 ± 1.9%, respectively), 2-fold higher than α4(β2α4)2. Our results indicate that the loss of function of nicotinic responses observed in α5DN-expressing ventral midbrain neurons is neither due to an intrinsic inability of this subunit to form functional nAChRs nor to an altered Ca(2+) permeability but likely to intracellular modulation.

  17. Organ-specific expression of glutamate dehydrogenase (GDH) subunits in yellow lupine.

    Science.gov (United States)

    Lehmann, Teresa; Dabert, Mirosława; Nowak, Witold

    2011-07-01

    Glutamate dehydrogenase (GDH, EC 1.4.2-4) is present in yellow lupine (Lupinus luteus cv. Juno) in many isoforms. The number and banding pattern of isoenzymes varies with respect to plant organ and developmental stage. To better understand the complex nature of GDH regulation in plants, the levels of GDH transcripts, enzyme activity and isoenzyme patterns in germinating seeds and roots of yellow lupine were examined. The analysis of GDH cDNA sequences in lupine revealed three mRNA types, of which two encoded the β-GDH subunit and one encoded the α-GDH subunit (corresponding to the GDH1(GDH3) and GDH2 genes, respectively). The relative expression of GDH1 and GDH2 genes was analyzed in various lupine organs by using quantitative real-time PCR. Our results indicate that different mRNA types were differently regulated depending on organ type. Although both genes appeared to be ubiquitously expressed in all lupine tissues, the GDH1 transcripts evidently predominated over those of GDH2. Immunochemical analyses confirmed that, during embryo development, varied expression of two GDH subunits takes place. The α-GDH subunit (43kDa) predominated in the early stages of germinating seeds, while the β-GDH subunit (44kDa) was the only GDH polypeptide present in lupine roots. These results firmly support the hypothesis that isoenzyme variability of GDH in yellow lupine is associated with the varied expression of α and β subunits into the complexes of hexameric GDH forms. The presence of several isogenes of GDH in yellow lupine may explain the high number (over 20) of its molecular forms in germinating lupine.

  18. Localization of the nucleic acid channel regulatory subunit, cytosolic malate dehydrogenase.

    Science.gov (United States)

    Hanss, Basil; Leal-Pinto, Edgar; Teixeira, Avelino; Tran, Baohuong; Lee, Chun-Hui; Henderson, Scott C; Klotman, Paul E

    2008-01-01

    NACh is a nucleic acid-conducting channel found in apical membrane of rat kidney proximal tubules. It is a heteromultimeric complex consisting of at least two proteins: a 45-kDa pore-forming subunit and a 36-kDa regulatory subunit. The regulatory subunit confers ion selectivity and influences gating kinetics. The regulatory subunit has been identified as cytosolic malate dehydrogenase (cMDH). cMDH is described in the literature as a soluble protein that is not associated with plasma membrane. Yet a role for cMDH as the regulatory subunit of NACh requires that it be present at the plasma membrane. To resolve this conflict, studies were initiated to determine whether cMDH could be found at the plasma membrane. Before performing localization studies, a suitable model system that expressed NACh was identified. A channel was identified in LLC-PK(1) cells, a line derived from pig proximal tubule, that is selective for nucleic acid and has a conductance of approximately 10 pS. It exhibits dose-dependent blockade by heparan sulfate or L-malate. These characteristics are similar to what has been reported for NACh from rat kidney and indicate that NACh is present in LLC-PK(1) cells. LLC-PK(1) cells were therefore used as a model system for immunolocalization of cMDH. Both immunofluorescence and immunoelectron microscopy demonstrated cMDH at the plasma membrane of LLC-PK(1) cells. This finding supports prior functional data that describe a role for cMDH as the regulatory subunit of NACh.

  19. The challenges of classical swine fever control: modified live and E2 subunit vaccines.

    Science.gov (United States)

    Huang, Yu-Liang; Deng, Ming-Chung; Wang, Fun-In; Huang, Chin-Cheng; Chang, Chia-Yi

    2014-01-22

    Classical swine fever (CSF) is an economically important, highly contagious disease of swine worldwide. CSF is caused by classical swine fever virus (CSFV), and domestic pigs and wild boars are its only natural hosts. The two main strategies used to control CSF epidemic are systematic prophylactic vaccination and a non-vaccination stamping-out policy. This review compares the protective efficacy of the routinely used modified live vaccine (MLV) and E2 subunit vaccines and summarizes the factors that influence the efficacy of the vaccines and the challenges that both vaccines face to CSF control. Although MLV provide earlier and more complete protection than E2 subunit vaccines, it has the drawback of not allowing differentiation between infected and vaccinated animals (DIVA). The marker vaccine of E2 protein with companion discriminatory test to detect antibodies against E(rns) allows DIVA and is a promising strategy for future control and eradication of CSF. Maternal derived antibody (MDA) is the critical factor in impairing the efficacy of both MLV and E2 subunit vaccines, so the well-designed vaccination programs of sows and piglets should be considered together. Because of the antigen variation among various genotypes of CSFV, antibodies raised by either MLV or subunit vaccine neutralize genotypically homologous strains better than heterologous ones. However, although this is not a major concern for MLV as the induced immune responses can protect pigs against the challenge of various genotypes of CSFVs, it is critical for E2 subunit vaccines. It is thus necessary to evaluate whether the E2 subunit vaccine can completely protect against the current prevalent strains in the field. An ideal new generation of vaccine should be able to maintain the high protective efficiency of MLV and overcome the problem of antigenic variations while allowing for DIVA.

  20. GABAA receptor β3 subunit expression regulates tonic current in developing striatopallidal medium spiny neurons

    Directory of Open Access Journals (Sweden)

    Megan eJanssen

    2011-07-01

    Full Text Available The striatum is a key structure for movement control, but the mechanisms that dictate the output of distinct subpopulations of medium spiny projection neurons (MSNs, striatonigral projecting and dopamine D1 receptor- (D1+ or striatopallidal projecting and dopamine D2 receptor- (D2+ expressing neurons, remains poorly understood. GABA-mediated tonic inhibition largely controls neuronal excitability and action potential firing rates, and we previously suggested with pharmacological analysis that the GABAA receptor β3 subunit plays a large role in the basal tonic current seen in D2+ MSNs from young mice (Ade et al, 2008; Janssen et al, 2009. In this study, we demonstrated the essential role of the β3 GABAA receptor subunit in mediating MSN tonic currents using conditional β3 subunit knock-out (β3f/fDrd2 mice. Cre-lox genetics were used to generate conditional knock-out animals where Cre recombinase was expressed under the D2 receptor (Drd2 promoter. We show that while the wild-type MSN tonic current pattern demonstrates a high degree of variability, tonic current patterns from β3f/fDrd2 mice are narrow, suggesting that the β3 subunit is essential to striatal MSN GABA-mediated tonic current. Our data also suggest that a distinct population of synaptic receptors upregulate due to β3 subunit removal. Further, deletion of this subunit significantly decreases the D2+ MSN excitability. These results offer insight for target mechanisms in Parkinson’s disease, where symptoms arise due to the imbalance in striatal D1+ and D2+ MSN excitability and output.

  1. Lack of immunological analogy between the beta-subunits of cholera toxin and human choriogonadotropin.

    Science.gov (United States)

    Acevedo, H F; Kellen, J A

    1986-01-01

    A chemical relatedness has been described between the beta-subunit of cholera toxin and that of the four dimeric glycoprotein hormones (hCG, hLH, hFSH and hTSH). However, antibodies induced by cholera toxin did not crossreact, when tested by labeled hCG binding and immunocytochemistry, with the beta-subunit of hCG. It appears that differences in the tertiary structures, as shown in this study, account for distinct epitopes. Similarities in biological activity between these two compounds, such as induction of adenyl cyclase or a protective effect against some tumors, are not based on immunological mechanisms.

  2. 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

  3. 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

  4. 126Gln is the residue of human IL-2 binding to IL-2R γ subunit

    Institute of Scientific and Technical Information of China (English)

    王志勇; 郑仲承; 孙兰英; 刘新垣

    1997-01-01

    The 126Gln of human interleukin-2 (IL-2) is a conserved amino acid residue. After substitution of 126Gln with Asp, the binding abilities of this mutant to different composites of IL-2 receptor (R) subunits have been determined. Results show that 126Asp-IL-2 has higher affinity to IL-2R α βγ complex and normal affinity to IL-2R α β complex, but loses its binding ability to IL-2R β γ complex, demonstrating that the 126Gln is the residue of human IL-2 which binds to IL-2R 7 subunit.

  5. The epithelial sodium channel γ-subunit is processed proteolytically in human kidney

    DEFF Research Database (Denmark)

    Langkilde, Rikke Zachar; Skjødt, Karsten; Marcussen, Niels

    2015-01-01

    The epithelial sodium channel (ENaC) of the kidney is necessary for extracellular volume homeostasis and normal arterial BP. Activity of ENaC is enhanced by proteolytic cleavage of the gamma-subunit and putative release of a 43-amino acid inhibitory tract from the gamma-subunit ectodomain. We......ENaC was detected consistently only in tissue from patients with proteinuria and observed in collecting ducts. In conclusion, human kidney gammaENaC is subject to proteolytic cleavage, yielding fragments compatible with furin cleavage, and proteinuria is associated with cleavage at the putative prostasin...

  6. The Brain-Specific Beta4 Subunit Downregulates BK Channel Cell Surface Expression

    OpenAIRE

    Sonal Shruti; Joanna Urban-Ciecko; Fitzpatrick, James A.; Robert Brenner; Bruchez, Marcel P.; Alison L Barth

    2012-01-01

    The large-conductance K(+) channel (BK channel) can control neural excitability, and enhanced channel currents facilitate high firing rates in cortical neurons. The brain-specific auxiliary subunit β4 alters channel Ca(++)- and voltage-sensitivity, and β4 knock-out animals exhibit spontaneous seizures. Here we investigate β4's effect on BK channel trafficking to the plasma membrane. Using a novel genetic tag to track the cellular location of the pore-forming BKα subunit in living cells, we fi...

  7. Ribosome formation from subunits studied by stopped-flow and Rayleigh light scattering

    Directory of Open Access Journals (Sweden)

    Antoun Ayman

    2004-01-01

    Full Text Available Light scattering and standard stopped-flow techniques were used to monitor rapid association of ribosomal subunits during initiation of eubacterial protein synthesis. The effects of the initiation factors IF1, IF2, IF3 and buffer conditions on subunit association were studied along with the role of GTP in this process. The part of light scattering theory that is essential for kinetic measurements is high-lighted in the main text and a more general treatment of Rayleigh scattering from macromolecules is given in an appendix.

  8. Cholinergic cells in the nucleus basalis of mice express the N-methyl-D-aspartate-receptor subunit NR2C and its replacement by the NR2B subunit enhances frontal and amygdaloid acetylcholine levels

    NARCIS (Netherlands)

    De Souza Silva, M. A.; Dolga, Amalia; Pieri, I.; Marchetti, L.; Eisel, U. L. M.; Huston, J. P.; Dere, E.

    2006-01-01

    It is known that glutamatergic and cholinergic systems interact functionally at the level of the cholinergic basal forebrain. The N-methyl-D-aspartate receptor (NMDA-R) is a multiprotein complex composed of NR1, NR2 and/or NR3 subunits. The subunit composition of NMDA-R of cholinergic cells in the n

  9. 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.

  10. Mutations in genes encoding subunits of RNA polymerases I and III cause Treacher Collins syndrome.

    NARCIS (Netherlands)

    Dauwerse, J.G.; Dixon, J.; Seland, S.; Ruivenkamp, C.A.; Haeringen, A. van; Hoefsloot, L.H.; Peters, D.J.; Boers, A.C.; Daumer-Haas, C.; Maiwald, R.; Zweier, C.; Kerr, B.; Cobo, A.M.; Toral, J.F.; Hoogeboom, A.J.M.; Lohmann, D.R.; Hehr, U.; Dixon, M.J.; Breuning, M.H.; Wieczorek, D.

    2011-01-01

    We identified a deletion of a gene encoding a subunit of RNA polymerases I and III, POLR1D, in an individual with Treacher Collins syndrome (TCS). Subsequently, we detected 20 additional heterozygous mutations of POLR1D in 252 individuals with TCS. Furthermore, we discovered mutations in both allele

  11. Structure of the ATP synthase from chloroplasts studied by electron microscopy. Localization of the small subunits

    NARCIS (Netherlands)

    Boekema, Egbert J.; Xiao, Jianping; McCarty, Richard E.

    1990-01-01

    The structure of the hydrophilic part of the ATP synthase from chloroplasts (CF1) has been further investigated by electron microscopy and image analysis of negatively stained samples. The projections of three different types of CF1 were analyzed: the holoenzyme with five different subunits and two

  12. 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...

  13. 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...

  14. Detailed analysis of the human mitochondrial contact site complex indicate a hierarchy of subunits.

    Science.gov (United States)

    Ott, Christine; Dorsch, Eva; Fraunholz, Martin; Straub, Sebastian; Kozjak-Pavlovic, Vera

    2015-01-01

    Mitochondrial inner membrane folds into cristae, which significantly increase its surface and are important for mitochondrial function. The stability of cristae depends on the mitochondrial contact site (MICOS) complex. In human mitochondria, the inner membrane MICOS complex interacts with the outer membrane sorting and assembly machinery (SAM) complex, to form the mitochondrial intermembrane space bridging complex (MIB). We have created knockdown cell lines of most of the MICOS and MIB components and have used them to study the importance of the individual subunits for the cristae formation and complex stability. We show that the most important subunits of the MIB complex in human mitochondria are Mic60/Mitofilin, Mic19/CHCHD3 and an outer membrane component Sam50. We provide additional proof that ApoO indeed is a subunit of the MICOS and MIB complexes and propose the name Mic23 for this protein. According to our results, Mic25/CHCHD6, Mic27/ApoOL and Mic23/ApoO appear to be periphery subunits of the MICOS complex, because their depletion does not affect cristae morphology or stability of other components.

  15. Purification and functional reconstitution of a seven-subunit mrp-type na+/h+ antiporter.

    Science.gov (United States)

    Morino, Masato; Suzuki, Toshiharu; Ito, Masahiro; Krulwich, Terry Ann

    2014-01-01

    Mrp antiporters and their homologues in the cation/proton antiporter 3 family of the Membrane Transporter Database are widely distributed in bacteria. They have major roles in supporting cation and cytoplasmic pH homeostasis in many environmental, extremophilic, and pathogenic bacteria. These antiporters require six or seven hydrophobic proteins that form hetero-oligomeric complexes, while most other cation/proton antiporters require only one membrane protein for their activity. The resemblance of three Mrp subunits to membrane-embedded subunits of the NADH:quinone oxidoreductase of respiratory chains and to subunits of several hydrogenases has raised interest in the evolutionary path and commonalities of their proton-translocating domains. In order to move toward a greater mechanistic understanding of these unusual antiporters and to rigorously demonstrate that they function as secondary antiporters, powered by an imposed proton motive force, we established a method for purification and functional reconstitution of the seven-subunit Mrp antiporter from alkaliphilic Bacillus pseudofirmus OF4. Na(+)/H(+) antiporter activity was demonstrated by a fluorescence-based assay with proteoliposomes in which the Mrp complex was coreconstituted with a bacterial FoF1-ATPase. Proton pumping by the ATPase upon addition of ATP generated a proton motive force across the membranes that powered antiporter activity upon subsequent addition of Na(+).

  16. 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

  17. Permethrin Induces Overexpression of Cytochrome c Oxidase Subunit 3 in Aedes aegypti

    Science.gov (United States)

    Using quantitative PCR (QPCR), the relative transcriptional levels of cytochrome c oxidase subunit 3 (CO3) were studied in Aedes aegypti (L.) in response to treatments with acetone, permethrin, or fipronil. The transcriptional levels of CO3 were significantly (p <0.05) higher in acetone-treated Ae. ...

  18. Stability of influenza sub-unit vaccine. Does a couple of days outside the refrigerator matter?

    NARCIS (Netherlands)

    Coenen, F; Tolboom, J T B M; Frijlink, H W

    2006-01-01

    In this study 27 full scale production batches of influenza sub-unit vaccine were evaluated on their stability. The batches varied with respect to the strains they contained and regarding the presence of the preservative thiomersal in the solution. The stability study showed that haemagglutinin cont

  19. Multimeric and trimeric subunit SP-D are interconvertible structures with distinct ligand interaction

    DEFF Research Database (Denmark)

    Sørensen, Grith Lykke; Hoegh, Silje V; Leth-Larsen, Rikke;

    2009-01-01

    Surfactant protein-D (SP-D) is a calcium dependent lectin in the innate immune system that facilitates clearance of microbes. The protein is associated with mucosal surfaces, and also found in bronchoalveolar lavage, serum and amniotic fluid. Human SP-D includes trimeric subunits and multimeric a...

  20. Recombinant cholera toxin B subunit in Escherichia coli: high-level secretion, purification, and characterization

    NARCIS (Netherlands)

    Slos, P.; Speck, D.; Accart, N.; Kolbe, H.V.; Schubnel, D.; Bouchon, B.; Bischoff, Rainer; Kieny, M.P.

    1994-01-01

    The gene coding for cholera toxin subunit B (CT-B) was fused to a modified ompA signal sequence and subsequently cloned into a high expression vector based on the regulatory signals of the arabinose operon of Salmonella typhimurium. Upon induction of gene expression in Escherichia coli, a product of