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Sample records for abc transporter required

  1. Phosphorylation is required for the pathogen defense function of the Arabidopsis PEN3 ABC transporter

    USDA-ARS?s Scientific Manuscript database

    The Arabidopsis PEN3 ABC transporter accumulates at sites of pathogen detection, where it is involved in defense against multiple pathogens. Perception of PAMPs by pattern recognition receptors initiates recruitment of PEN3 and also leads to PEN3 phosphorylation at multiple amino acid residues. Whet...

  2. Phosphorylation is required for the pathogen defense function of the Arabidopsis PEN3 ABC transporter.

    PubMed

    Underwood, William; Somerville, Shauna C

    2017-10-03

    The Arabidopsis PEN3 ABC transporter accumulates at sites of pathogen detection, where it is involved in defense against a number of pathogens. Perception of PAMPs by pattern recognition receptors initiates recruitment of PEN3 and also leads to PEN3 phosphorylation at multiple amino acid residues. Whether PAMP-induced phosphorylation of PEN3 is important for its defense function or focal recruitment has not been addressed. In this study, we evaluated the role of PEN3 phosphorylation in modulating the localization and defense function of the transporter. We report that PEN3 phosphorylation is critical for its function in defense, but dispensable for recruitment to powdery mildew penetration sites. These results indicate that PAMP-induced phosphorylation is likely to regulate the transport activity of PEN3.

  3. The ABC transporter Tba of Amycolatopsis balhimycina is required for efficient export of the glycopeptide antibiotic balhimycin.

    PubMed

    Menges, R; Muth, G; Wohlleben, W; Stegmann, E

    2007-11-01

    All known gene clusters for glycopeptide antibiotic biosynthesis contain a conserved gene supposed to encode an ABC-transporter. In the balhimycin-producer Amycolatopsis balhimycina this gene (tba) is localised between the prephenate dehydrogenase gene pdh and the peptide synthetase gene bpsA. Inactivation of tba in A. balhimycina by gene replacement did not interfere with growth and did not affect balhimycin resistance. However, in the supernatant of the tba mutant RM43 less balhimycin was accumulated compared to the wild type; and the intra-cellular balhimycin concentration was ten times higher in the tba mutant RM43 than in the wild type. These data suggest that the ABC transporter encoded in the balhimycin biosynthesis gene cluster is not involved in resistance but is required for the efficient export of the antibiotic. To elucidate the activity of Tba it was heterologously expressed in Escherichia coli with an N-terminal His-tag and purified by nickel chromatography. A photometric assay revealed that His(6)-Tba solubilised in dodecylmaltoside possesses ATPase activity, characteristic for ABC-transporters.

  4. [The ABC transporters of Saccharomyces cerevisiae].

    PubMed

    Wawrzycka, Donata

    2011-01-01

    The ABC transporters (ATP Binding Cassette) compose one of the bigest protein family with the great medical, industrial and economical impact. They are found in all organism from bacteria to man. ABC proteins are responsible for resistance of microorganism to antibiotics and fungicides and multidrug resistance of cancer cells. Mutations in ABC transporters genes cause seriuos deseases like cystic fibrosis, adrenoleucodystrophy or ataxia. Transport catalized by ABC proteins is charged with energy from the ATP hydrolysis. The ABC superfamily contains transporters, canals, receptors. Analysis of the Saccharomyces cerevisiae genome allowed to distinguish 30 potential ABC proteins which are classified into 6 subfamilies. The structural and functional similarity of the yeast and human ABC proteins allowes to use the S. cerevisiae as a model organism for ABC transporters characterisation. In this work the present state of knowleadge on yeast S. cerevisiae ABC proteins was summarised.

  5. ALS3 encodes a phloem-localized ABC transporter-like protein that is required for aluminum tolerance in Arabidopsis.

    PubMed

    Larsen, Paul B; Geisler, Matt J B; Jones, Carol A; Williams, Kelly M; Cancel, Jesse D

    2005-02-01

    Aluminum (Al) toxicity in acid soils is a worldwide agricultural problem that severely limits crop productivity through inhibition of root growth. Previously, Arabidopsis mutants with increased Al sensitivity were isolated in order to identify genes important for Al tolerance in plants. One mutant, als3, exhibited extreme root growth inhibition in the presence of Al, suggesting that this mutation negatively impacts a gene required for Al tolerance. Map-based cloning of the als3-1 mutation resulted in the isolation of a novel gene that encodes a previously undescribed ABC transporter-like protein, which is highly homologous to a putative bacterial metal resistance protein, ybbM. Northern analysis for ALS3 expression revealed that it is found in all organs examined, which is consistent with the global nature of Al sensitivity displayed by als3, and that expression increases in roots following Al treatment. Based on GUS fusion and in situ hybridization analyses, ALS3 is primarily expressed in leaf hydathodes and the phloem throughout the plant, along with the root cortex following Al treatment. Immunolocalization indicates that ALS3 predominantly accumulates in the plasma membrane of cells that express ALS3. From our results, it appears that ALS3 encodes an ABC transporter-like protein that is required for Al resistance/tolerance and may function to redistribute accumulated Al away from sensitive tissues in order to protect the growing root from the toxic effects of Al.

  6. Catalytic and transport cycles of ABC exporters.

    PubMed

    Al-Shawi, Marwan K

    2011-09-07

    ABC (ATP-binding cassette) transporters are arguably the most important family of ATP-driven transporters in biology. Despite considerable effort and advances in determining the structures and physiology of these transporters, their fundamental molecular mechanisms remain elusive and highly controversial. How does ATP hydrolysis by ABC transporters drive their transport function? Part of the problem in answering this question appears to be a perceived need to formulate a universal mechanism. Although it has been generally hoped and assumed that the whole superfamily of ABC transporters would exhibit similar conserved mechanisms, this is proving not to be the case. Structural considerations alone suggest that there are three overall types of coupling mechanisms related to ABC exporters, small ABC importers and large ABC importers. Biochemical and biophysical characterization leads us to the conclusion that, even within these three classes, the catalytic and transport mechanisms are not fully conserved, but continue to evolve. ABC transporters also exhibit unusual characteristics not observed in other primary transporters, such as uncoupled basal ATPase activity, that severely complicate mechanistic studies by established methods. In this chapter, I review these issues as related to ABC exporters in particular. A consensus view has emerged that ABC exporters follow alternating-access switch transport mechanisms. However, some biochemical data suggest that alternating catalytic site transport mechanisms are more appropriate for fully symmetrical ABC exporters. Heterodimeric and asymmetrical ABC exporters appear to conform to simple alternating-access-type mechanisms.

  7. Translocation of the ABC transporter ABCD4 from the endoplasmic reticulum to lysosomes requires the escort protein LMBD1.

    PubMed

    Kawaguchi, Kosuke; Okamoto, Takumi; Morita, Masashi; Imanaka, Tsuneo

    2016-07-26

    We previously demonstrated that ABCD4 does not localize to peroxisomes but rather, the endoplasmic reticulum (ER), because it lacks the NH2-terminal hydrophilic region required for peroxisomal targeting. It was recently reported that mutations in ABCD4 result in a failure to release vitamin B12 from lysosomes. A similar phenotype is caused by mutations in LMBRD1, which encodes the lysosomal membrane protein LMBD1. These findings suggested to us that ABCD4 translocated from the ER to lysosomes in association with LMBD1. In this report, it is demonstrated that ABCD4 interacts with LMBD1 and then localizes to lysosomes, and this translocation depends on the lysosomal targeting ability of LMBD1. Furthermore, endogenous ABCD4 was localized to both lysosomes and the ER, and its lysosomal localization was disturbed by knockout of LMBRD1. To the best of our knowledge, this is the first report demonstrating that the subcellular localization of the ABC transporter is determined by its association with an adaptor protein.

  8. ABC-B transporter genes in Dirofilaria immitis.

    PubMed

    Bourguinat, Catherine; Che, Hua; Mani, Thangadurai; Keller, Kathy; Prichard, Roger K

    2016-08-01

    Dirofilaria immitis is a filarial nematode causing infection and heartworm disease in dogs and other canids, cats, and occasionally in humans. Prevention with macrocyclic lactones (ML) is recommended during the mosquito transmission season. Recently, ML resistance has been reported. ABC-B transporter genes are thought to be involved in the mechanism of ML resistance in other nematodes. This study aimed to identify all the ABC-B transporter genes in D. immitis using as a reference the nDi.2.2 D. immitis whole genome, which is not completely annotated. Using bioinformatic tools and PCR amplification on pooled D. immitis genomic DNA and on pooled cDNA, nine ABC transporter genes including one pseudogene were characterized. Bioinformatic and phylogenetic analyses allowed identification of three P-glycoproteins (Pgps) (Dim-pgp-3 Dim-pgp-10, Dim-pgp-11), of two ABC-B half transporter genes (one ortholog of Cel-haf-4 and Cel-haf-9; and one ortholog of Cel-haf-1 and Cel-haf-3), of one ABC half transporter gene (ortholog of Cel-haf-5) that contained an ABC-C motif, and of one additional half transporter that would require functional study for characterization. The number of ABC-B transporter genes identified was lower than in Caenorhabditis elegans and Haemonchus contortus. Further studies are needed to understand their possible role in ML resistance in D. immitis. These ABC transporters constitute a base for ML resistance investigation in D. immitis and advance our understanding of the molecular biology of this parasite. Copyright © 2016. Published by Elsevier Ltd.

  9. The Pseudomonas aeruginosa PA14 ABC Transporter NppA1A2BCD Is Required for Uptake of Peptidyl Nucleoside Antibiotics.

    PubMed

    Pletzer, Daniel; Braun, Yvonne; Dubiley, Svetlana; Lafon, Corinne; Köhler, Thilo; Page, Malcolm G P; Mourez, Michael; Severinov, Konstantin; Weingart, Helge

    2015-07-01

    Analysis of the genome sequence of Pseudomonas aeruginosa PA14 revealed the presence of an operon encoding an ABC-type transporter (NppA1A2BCD) showing homology to the Yej transporter of Escherichia coli. The Yej transporter is involved in the uptake of the peptide-nucleotide antibiotic microcin C, a translation inhibitor that targets the enzyme aspartyl-tRNA synthetase. Furthermore, it was recently shown that the Opp transporter from P. aeruginosa PAO1, which is identical to Npp, is required for uptake of the uridyl peptide antibiotic pacidamycin, which targets the enzyme translocase I (MraY), which is involved in peptidoglycan synthesis. We used several approaches to further explore the substrate specificity of the Npp transporter. Assays of growth in defined minimal medium containing peptides of various lengths and amino acid compositions as sole nitrogen sources, as well as Biolog Phenotype MicroArrays, showed that the Npp transporter is not required for di-, tri-, and oligopeptide uptake. Overexpression of the npp operon increased susceptibility not just to pacidamycin but also to nickel chloride and the peptidyl nucleoside antibiotic blasticidin S. Furthermore, heterologous expression of the npp operon in a yej-deficient mutant of E. coli resulted in increased susceptibility to albomycin, a naturally occurring sideromycin with a peptidyl nucleoside antibiotic. Additionally, heterologous expression showed that microcin C is recognized by the P. aeruginosa Npp system. Overall, these results suggest that the NppA1A2BCD transporter is involved in the uptake of peptidyl nucleoside antibiotics by P. aeruginosa PA14. One of the world's most serious health problems is the rise of antibiotic-resistant bacteria. There is a desperate need to find novel antibiotic therapeutics that either act on new biological targets or are able to bypass known resistance mechanisms. Bacterial ABC transporters play an important role in nutrient uptake from the environment. These uptake

  10. Evolutionary Trajectories of Entomopathogenic Fungi ABC Transporters.

    PubMed

    Baral, Bikash

    2017-01-01

    The ABC protein superfamily-also called traffic ATPases-are energy-dependent ubiquitous proteins, representing one of the crucial and the largest family in the fungal genomes. The ATP-binding cassette endows a characteristic 200-250 amino acids and is omnipresent in all organisms ranging from prokaryotes to eukaryotes. Unlike in bacteria with nutrient import functions, ABC transporters in fungal entomopathogens serve as effective efflux pumps that are largely involved in the shuttle of metabolites across the biological membranes. Thus, the search for ABC proteins may prove of immense importance in elucidating the functional and molecular mechanism at the host-pathogen (insect-fungus) interface. Their sequence homology, domain topology, and functional traits led to the actual identification of nine different families in fungal entomopathogens. Evolutionary relationships within the ABC superfamily are discussed, concentrating on computational approaches for comparative identification of ABC transporters in insect-pathogenic fungi (entomopathogens) with those of animals, plants, and their bacterial orthologs. Ancestors of some fungal candidates have duplicated extensively in some phyla, while others were lost in one lineage or the other, and predictions for the cause of their duplications and/or loss in some phyla are made. ABC transporters of fungal insect-pathogens serve both defensive and offensive functions effective against land-dwelling and ground foraging voracious insects. This study may help to unravel the molecular cascades of ABC proteins to illuminate the means through which insects cope with fungal infection and fungal-related diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Requirement of ABC transporter inhibition and Hoechst 33342 dye deprivation for the assessment of side population-defined C6 glioma stem cell metabolism using fluorescent probes.

    PubMed

    Murota, Yoshitaka; Tabu, Kouichi; Taga, Tetsuya

    2016-11-04

    JC-1 aggregates in such SP and MP cells became comparable. Inhibiting ABC transporters and depriving Hoechst 33342 dye are required for the accurate assessment of side population-defined C6 glioma stem cell metabolism using fluorescent probes.

  12. Zinc transporters YbtX and ZnuABC are required for the virulence of Yersinia pestis in bubonic and pneumonic plague in mice.

    PubMed

    Bobrov, Alexander G; Kirillina, Olga; Fosso, Marina Y; Fetherston, Jacqueline D; Miller, M Clarke; VanCleave, Tiva T; Burlison, Joseph A; Arnold, William K; Lawrenz, Matthew B; Garneau-Tsodikova, Sylvie; Perry, Robert D

    2017-06-21

    A number of bacterial pathogens require the ZnuABC Zinc (Zn 2+ ) transporter and/or a second Zn 2+ transport system to overcome Zn 2+ sequestration by mammalian hosts. Previously we have shown that in addition to ZnuABC, Yersinia pestis possesses a second Zn 2+ transporter that involves components of the yersiniabactin (Ybt), siderophore-dependent iron transport system. Synthesis of the Ybt siderophore and YbtX, a member of the major facilitator superfamily, are both critical components of the second Zn 2+ transport system. Here we demonstrate that a ybtX znu double mutant is essentially avirulent in mouse models of bubonic and pneumonic plague while a ybtX mutant retains high virulence in both plague models. While sequestration of host Zn is a key nutritional immunity factor, excess Zn appears to have a significant antimicrobial role in controlling intracellular bacterial survival. Here, we demonstrate that ZntA, a Zn 2+ exporter, plays a role in resistance to Zn toxicity in vitro, but that a zntA zur double mutant retains high virulence in both pneumonic and bubonic plague models and survival in macrophages. We also confirm that Ybt does not directly bind Zn 2+ in vitro under the conditions tested. However, we detect a significant increase in Zn 2+ -binding ability of filtered supernatants from a Ybt + strain compared to those from a strain unable to produce the siderophore, supporting our previously published data that Ybt biosynthetic genes are involved in the production of a secreted Zn-binding molecule (zincophore). Our data suggest that Ybt or a modified Ybt participate in or promote Zn-binding activity in culture supernatants and is involved in Zn acquisition in Y. pestis.

  13. The trehalose-specific transporter LpqY-SugABC is required for antimicrobial and anti-biofilm activity of trehalose analogues in Mycobacterium smegmatis.

    PubMed

    Wolber, Jeffrey M; Urbanek, Bailey L; Meints, Lisa M; Piligian, Brent F; Lopez-Casillas, Irene C; Zochowski, Kailey M; Woodruff, Peter J; Swarts, Benjamin M

    2017-10-10

    Mycobacteria, including the bacterial pathogen that causes human tuberculosis, possess distinctive pathways for synthesizing and utilizing the non-mammalian disaccharide trehalose. Trehalose metabolism is essential for mycobacterial viability and has been linked to in vitro biofilm formation, which may bear relevance to in vivo drug tolerance. Previous research has shown that some trehalose analogues bearing modifications at the 6-position inhibit growth of various mycobacterial species. In this work, 2-, 5-, and 6-position-modified trehalose analogues were synthesized using our previously reported one-step chemoenzymatic method and shown to inhibit growth and biofilm formation in the two-to three-digit micromolar range in Mycobacterium smegmatis. The trehalose-specific ABC transporter LpqY-SugABC was essential for antimicrobial and anti-biofilm activity, suggesting that inhibition by monosubstituted trehalose analogues requires cellular uptake and does not proceed via direct action on extracellular targets such as antigen 85 acyltransferases or trehalose dimycolate hydrolase. Although the potency of the described compounds in in vitro growth and biofilm assays is moderate, this study reports the first trehalose-based mycobacterial biofilm inhibitors and reinforces the concept of exploiting unique sugar uptake pathways to deliver inhibitors and other chemical cargo to mycobacteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Diversity in ABC transporters: Type I, II and III importers

    PubMed Central

    Rice, Austin J.; Park, Aekyung

    2014-01-01

    ATP-binding cassette transporters are multi-subunit membrane pumps that transport substrates across membranes. While significant in the transport process, transporter architecture exhibits a range of diversity that we are only beginning to recognize. This divergence may provide insight into the mechanisms of substrate transport and homeostasis. Until recently, ABC importers have been classified into two types, but with the emergence of energy-coupling factor (ECF) transporters there are potentially three types of ABC importers. In this review, we summarize an expansive body of research on the three types of importers with an emphasis on the basics that underlie ABC importers, such as structure, subunit composition and mechanism. PMID:25155087

  15. Biochemical characterization of an ABC transporter LptBFGC complex required for the outer membrane sorting of lipopolysaccharides.

    PubMed

    Narita, Shin-ichiro; Tokuda, Hajime

    2009-07-07

    Seven Lpt proteins (A through G) are thought to be involved in lipopolysaccharide transport from the inner to outer membrane of Escherichia coli. LptB belongs to the ATP-binding cassette transporter superfamily. Although the lptB gene lacks neighboring genes encoding membrane subunits, bioinformatic analyses recently indicated that two distantly located consecutive genes, lptF and lptG, could encode membrane subunits. To examine this possibility, LptB was expressed with LptF and LptG. We report here that both LptF and LptG formed a complex with LptB. Furthermore, an inner membrane protein, LptC, which had been implicated in lipopolysaccharide transport, was also included in this complex.

  16. An ABC transporter B family protein, ABCB19, is required for cytoplasmic streaming and gravitropism of the inflorescence stems.

    PubMed

    Okamoto, Keishi; Ueda, Haruko; Shimada, Tomoo; Tamura, Kentaro; Koumoto, Yasuko; Tasaka, Masao; Morita, Miyo Terao; Hara-Nishimura, Ikuko

    2016-01-01

    A significant feature of plant cells is the extensive motility of organelles and the cytosol, which was originally defined as cytoplasmic streaming. We suggested previously that a three-way interaction between plant-specific motor proteins myosin XIs, actin filaments, and the endoplasmic reticulum (ER) was responsible for cytoplasmic streaming. (1) Currently, however, there are no reports of molecular components for cytoplasmic streaming other than the actin-myosin-cytoskeleton and ER-related proteins. In the present study, we found that elongated cells of inflorescence stems of Arabidopsis thaliana exhibit vigorous cytoplasmic streaming. Statistical analysis showed that the maximal velocity of plastid movements is 7.26 µm/s, which is much faster than the previously reported velocities of organelles. Surprisingly, the maximal velocity of streaming in the inflorescence stem cells was significantly reduced to 1.11 µm/s in an Arabidopsis mutant, abcb19-101, which lacks ATP BINDING CASSETTE SUBFAMILY B19 (ABCB19) that mediates the polar transport of the phytohormone auxin together with PIN-FORMED (PIN) proteins. Polar auxin transport establishes the auxin concentration gradient essential for plant development and tropisms. Deficiency of ABCB19 activity eventually caused enhanced gravitropic responses of the inflorescence stems and abnormally flexed inflorescence stems. These results suggest that ABCB19-mediated auxin transport plays a role not only in tropism regulation, but also in cytoplasmic streaming.

  17. Placental ABC Transporters: Biological Impact and Pharmaceutical Significance.

    PubMed

    Joshi, Anand A; Vaidya, Soniya S; St-Pierre, Marie V; Mikheev, Andrei M; Desino, Kelly E; Nyandege, Abner N; Audus, Kenneth L; Unadkat, Jashvant D; Gerk, Phillip M

    2016-12-01

    The human placenta fulfills a variety of essential functions during prenatal life. Several ABC transporters are expressed in the human placenta, where they play a role in the transport of endogenous compounds and may protect the fetus from exogenous compounds such as therapeutic agents, drugs of abuse, and other xenobiotics. To date, considerable progress has been made toward understanding ABC transporters in the placenta. Recent studies on the expression and functional activities are discussed. This review discusses the placental expression and functional roles of several members of ABC transporter subfamilies B, C, and G including MDR1/P-glycoprotein, the MRPs, and BCRP, respectively. Since placental ABC transporters modulate fetal exposure to various compounds, an understanding of their functional and regulatory mechanisms will lead to more optimal medication use when necessary in pregnancy.

  18. Placental ABC Transporters: Biological Impact and Pharmaceutical Significance

    PubMed Central

    Joshi, Anand A.; Vaidya, Soniya S.; St-Pierre, Marie V.; Mikheev, Andrei M.; Desino, Kelly E.; Nyandege, Abner N.; Audus, Kenneth L.; Unadkat, Jashvant D.; Gerk, Phillip M.

    2017-01-01

    The human placenta fulfills a variety of essential functions during prenatal life. Several ABC transporters are expressed in the human placenta, where they play a role in the transport of endogenous compounds and may protect the fetus from exogenous compounds such as therapeutic agents, drugs of abuse, and other xenobiotics. To date, considerable progress has been made toward understanding ABC transporters in the placenta. Recent studies on the expression and functional activities are discussed. This review discusses the placental expression and functional roles of several members of ABC transporter subfamilies B, C, and G including MDR1/P-glycoprotein, the MRPs, and BCRP, respectively. Since placental ABC transporters modulate fetal exposure to various compounds, an understanding of their functional and regulatory mechanisms will lead to more optimal medication use when necessary in pregnancy. PMID:27644937

  19. Comparison of mechanistic transport cycle models of ABC exporters.

    PubMed

    Szöllősi, Dániel; Rose-Sperling, Dania; Hellmich, Ute A; Stockner, Thomas

    2018-04-01

    ABC (ATP binding cassette) transporters, ubiquitous in all kingdoms of life, carry out essential substrate transport reactions across cell membranes. Their transmembrane domains bind and translocate substrates and are connected to a pair of nucleotide binding domains, which bind and hydrolyze ATP to energize import or export of substrates. Over four decades of investigations into ABC transporters have revealed numerous details from atomic-level structural insights to their functional and physiological roles. Despite all these advances, a comprehensive understanding of the mechanistic principles of ABC transporter function remains elusive. The human multidrug resistance transporter ABCB1, also referred to as P-glycoprotein (P-gp), is one of the most intensively studied ABC exporters. Using ABCB1 as the reference point, we aim to compare the dominating mechanistic models of substrate transport and ATP hydrolysis for ABC exporters and to highlight the experimental and computational evidence in their support. In particular, we point out in silico studies that enhance and complement available biochemical data. "This article is part of a Special Issue entitled: Beyond the Structure-Function Horizon of Membrane Proteins edited by Ute Hellmich, Rupak Doshi and Benjamin McIlwain." Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  20. ABC Transporters Involved in Export of Cell Surface Glycoconjugates

    PubMed Central

    Cuthbertson, Leslie; Kos, Veronica; Whitfield, Chris

    2010-01-01

    Summary: Complex glycoconjugates play critical roles in the biology of microorganisms. Despite the remarkable diversity in glycan structures and the bacteria that produce them, conserved themes are evident in the biosynthesis-export pathways. One of the primary pathways involves representatives of the ATP-binding cassette (ABC) transporter superfamily. These proteins are responsible for the export of a wide variety of cell surface oligo- and polysaccharides in both Gram-positive and Gram-negative bacteria. Recent investigations of the structure and function of ABC transporters involved in the export of lipopolysaccharide O antigens have revealed two fundamentally different strategies for coupling glycan polymerization to export. These mechanisms are distinguished by the presence (or absence) of characteristic nonreducing terminal modifications on the export substrates, which serve as chain termination and/or export signals, and by the presence (or absence) of a discrete substrate-binding domain in the nucleotide-binding domain polypeptide of the ABC transporter. A bioinformatic survey examining ABC exporters from known oligo- and polysaccharide biosynthesis loci identifies conserved nucleotide-binding domain protein families that correlate well with themes in the structures and assembly of glycans. The familial relationships among the ABC exporters generate hypotheses concerning the biosynthesis of structurally diverse oligo- and polysaccharides, which play important roles in the biology of bacteria with different lifestyles. PMID:20805402

  1. RCN1/OsABCG5, an ATP-binding cassette (ABC) transporter, is required for hypodermal suberization of roots in rice (Oryza sativa).

    PubMed

    Shiono, Katsuhiro; Ando, Miho; Nishiuchi, Shunsaku; Takahashi, Hirokazu; Watanabe, Kohtaro; Nakamura, Motoaki; Matsuo, Yuichi; Yasuno, Naoko; Yamanouchi, Utako; Fujimoto, Masaru; Takanashi, Hideki; Ranathunge, Kosala; Franke, Rochus B; Shitan, Nobukazu; Nishizawa, Naoko K; Takamure, Itsuro; Yano, Masahiro; Tsutsumi, Nobuhiro; Schreiber, Lukas; Yazaki, Kazufumi; Nakazono, Mikio; Kato, Kiyoaki

    2014-10-01

    Suberin is a complex polymer composed of aliphatic and phenolic compounds. It is a constituent of apoplastic plant interfaces. In many plant species, including rice (Oryza sativa), the hypodermis in the outer part of roots forms a suberized cell wall (the Casparian strip and/or suberin lamellae), which inhibits the flow of water and ions and protects against pathogens. To date, there is no genetic evidence that suberin forms an apoplastic transport barrier in the hypodermis. We discovered that a rice reduced culm number1 (rcn1) mutant could not develop roots longer than 100 mm in waterlogged soil. The mutated gene encoded an ATP-binding cassette (ABC) transporter named RCN1/OsABCG5. RCN1/OsABCG5 gene expression in the wild type was increased in most hypodermal and some endodermal roots cells under stagnant deoxygenated conditions. A GFP-RCN1/OsABCG5 fusion protein localized at the plasma membrane of the wild type. Under stagnant deoxygenated conditions, well suberized hypodermis developed in wild types but not in rcn1 mutants. Under stagnant deoxygenated conditions, apoplastic tracers (periodic acid and berberine) were blocked at the hypodermis in the wild type but not in rcn1, indicating that the apoplastic barrier in the mutant was impaired. The amount of the major aliphatic suberin monomers originating from C(28) and C(30) fatty acids or ω-OH fatty acids was much lower in rcn1 than in the wild type. These findings suggest that RCN1/OsABCG5 has a role in the suberization of the hypodermis of rice roots, which contributes to formation of the apoplastic barrier. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

  2. ABC transporters and immunity: mechanism of self-defense.

    PubMed

    Hinz, Andreas; Tampé, Robert

    2012-06-26

    The transporter associated with antigen processing (TAP) is a prototype of an asymmetric ATP-binding cassette (ABC) transporter, which uses ATP binding and hydrolysis to translocate peptides from the cytosol to the lumen of the endoplasmic reticulum (ER). Here, we review molecular details of peptide binding and ATP binding and hydrolysis as well as the resulting allosteric cross-talk between the nucleotide-binding domains and the transmembrane domains that drive translocation of the solute across the ER membrane. We also discuss the general molecular architecture of ABC transporters and demonstrate the importance of structural and functional studies for a better understanding of the role of the noncanonical site of asymmetric ABC transporters. Several aspects of peptide binding and specificity illustrate details of peptide translocation by TAP. Furthermore, this ABC transporter forms the central part of the major histocompatibility complex class I (MHC I) peptide-loading machinery. Hence, TAP is confronted with a number of viral factors, which prevent antigen translocation and MHC I loading in virally infected cells. We review how these viral factors have been used as molecular tools to decipher mechanistic aspects of solute translocation and discuss how they can help in the structural analysis of TAP.

  3. The mitochondrial transporter ABC-me (ABCB10), a downstream target of GATA-1, is essential for erythropoiesis in vivo.

    PubMed

    Hyde, B B; Liesa, M; Elorza, A A; Qiu, W; Haigh, S E; Richey, L; Mikkola, H K; Schlaeger, T M; Shirihai, O S

    2012-07-01

    The mitochondrial transporter ATP binding cassette mitochondrial erythroid (ABC-me/ABCB10) is highly induced during erythroid differentiation by GATA-1 and its overexpression increases hemoglobin production rates in vitro. However, the role of ABC-me in erythropoiesis in vivo is unknown. Here we report for the first time that erythrocyte development in mice requires ABC-me. ABC-me-/- mice die at day 12.5 of gestation, showing nearly complete eradication of primitive erythropoiesis and lack of hemoglobinized cells at day 10.5. ABC-me-/- erythroid cells fail to differentiate because they exhibit a marked increase in apoptosis, both in vivo and ex vivo. Erythroid precursors are particularly sensitive to oxidative stress and ABC-me in the heart and its yeast ortholog multidrug resistance-like 1 have been shown to protect against oxidative stress. Thus, we hypothesized that increased apoptosis in ABC-me-/- erythroid precursors was caused by oxidative stress. Within this context, ABC-me deletion causes an increase in mitochondrial superoxide production and protein carbonylation in erythroid precursors. Furthermore, treatment of ABC-me-/- erythroid progenitors with the mitochondrial antioxidant MnTBAP (superoxide dismutase 2 mimetic) supports survival, ex vivo differentiation and increased hemoglobin production. Altogether, our findings demonstrate that ABC-me is essential for erythropoiesis in vivo.

  4. The mitochondrial transporter ABC-me (ABCB10), a downstream target of GATA-1, is essential for erythropoiesis in vivo

    PubMed Central

    Hyde, B B; Liesa, M; Elorza, A A; Qiu, W; Haigh, S E; Richey, L; Mikkola, H K; Schlaeger, T M; Shirihai, O S

    2012-01-01

    The mitochondrial transporter ATP binding cassette mitochondrial erythroid (ABC-me/ABCB10) is highly induced during erythroid differentiation by GATA-1 and its overexpression increases hemoglobin production rates in vitro. However, the role of ABC-me in erythropoiesis in vivo is unknown. Here we report for the first time that erythrocyte development in mice requires ABC-me. ABC-me−/− mice die at day 12.5 of gestation, showing nearly complete eradication of primitive erythropoiesis and lack of hemoglobinized cells at day 10.5. ABC-me−/− erythroid cells fail to differentiate because they exhibit a marked increase in apoptosis, both in vivo and ex vivo. Erythroid precursors are particularly sensitive to oxidative stress and ABC-me in the heart and its yeast ortholog multidrug resistance-like 1 have been shown to protect against oxidative stress. Thus, we hypothesized that increased apoptosis in ABC-me−/− erythroid precursors was caused by oxidative stress. Within this context, ABC-me deletion causes an increase in mitochondrial superoxide production and protein carbonylation in erythroid precursors. Furthermore, treatment of ABC-me−/− erythroid progenitors with the mitochondrial antioxidant MnTBAP (superoxide dismutase 2 mimetic) supports survival, ex vivo differentiation and increased hemoglobin production. Altogether, our findings demonstrate that ABC-me is essential for erythropoiesis in vivo. PMID:22240895

  5. The interaction of gut microbes with host ABC transporters

    PubMed Central

    Mercado-Lubo, Regino

    2010-01-01

    ATP binding cassette (ABC) transporters are increasingly recognized for their ability to modulate the absorption, distribution, metabolism, secretion and toxicity of xenobiotics. In addition to their essential function in drug resistance, there is also emerging evidence documenting the important role ABC transporters play in tissue defense. In this respect, the gastrointestinal tract represents a critical vanguard of defense against oral exposure of drugs while at the same time functions as a physical barrier between the lumenal contents (including bacteria) and the intestinal epithelium. Given emerging evidence suggesting that multidrug resistance protein (MDR) plays an important role in host-bacterial interactions in the gastrointestinal tract, this review will discuss the interplay between MDR of the intestinal epithelial cell barrier and gut microbes in health and disease. In particular, we will explore host-microbe interactions involving three apically restricted ABC transporters of the intestinal epithelium; P-glycoprotein (P-gp), multidrug resistance-associated protein 2 (MRP2) and cystic fibrosis transmembrane regulator (CFTR). PMID:21327038

  6. Structure of a Type-1 Secretion System ABC Transporter.

    PubMed

    Morgan, Jacob L W; Acheson, Justin F; Zimmer, Jochen

    2017-03-07

    Type-1 secretion systems (T1SSs) represent a widespread mode of protein secretion across the cell envelope in Gram-negative bacteria. The T1SS is composed of an inner-membrane ABC transporter, a periplasmic membrane-fusion protein, and an outer-membrane porin. These three components assemble into a complex spanning both membranes and providing a conduit for the translocation of unfolded polypeptides. We show that ATP hydrolysis and assembly of the entire T1SS complex is necessary for protein secretion. Furthermore, we present a 3.15-Å crystal structure of AaPrtD, the ABC transporter found in the Aquifex aeolicus T1SS. The structure suggests a substrate entry window just above the transporter's nucleotide binding domains. In addition, highly kinked transmembrane helices, which frame a narrow channel not observed in canonical peptide transporters, are likely involved in substrate translocation. Overall, the AaPrtD structure supports a polypeptide transport mechanism distinct from alternating access. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. A bacterial-type ABC transporter is involved in aluminum tolerance in rice.

    PubMed

    Huang, Chao Feng; Yamaji, Naoki; Mitani, Namiki; Yano, Masahiro; Nagamura, Yoshiaki; Ma, Jian Feng

    2009-02-01

    Aluminum (Al) toxicity is a major factor limiting crop production in acidic soil, but the molecular mechanisms of Al tolerance are poorly understood. Here, we report that two genes, STAR1 (for sensitive to Al rhizotoxicity1) and STAR2, are responsible for Al tolerance in rice. STAR1 encodes a nucleotide binding domain, while STAR2 encodes a transmembrane domain, of a bacterial-type ATP binding cassette (ABC) transporter. Disruption of either gene resulted in hypersensitivity to aluminum toxicity. Both STAR1 and STAR2 are expressed mainly in the roots and are specifically induced by Al exposure. Expression in onion epidermal cells, rice protoplasts, and yeast showed that STAR1 interacts with STAR2 to form a complex that localizes to the vesicle membranes of all root cells, except for those in the epidermal layer of the mature zone. When expressed together in Xenopus laevis oocytes, STAR1/2 shows efflux transport activity specific for UDP-glucose. Furthermore, addition of exogenous UDP-glucose rescued root growth in the star1 mutant exposed to Al. These results indicate that STAR1 and STAR2 form a complex that functions as an ABC transporter, which is required for detoxification of Al in rice. The ABC transporter transports UDP-glucose, which may be used to modify the cell wall.

  8. Toward Determining ATPase Mechanism in ABC Transporters: Development of the Reaction Path–Force Matching QM/MM Method

    PubMed Central

    Zhou, Y.; Ojeda-May, P.; Nagaraju, M.; Pu, J.

    2016-01-01

    Adenosine triphosphate (ATP)-binding cassette (ABC) transporters are ubiquitous ATP-dependent membrane proteins involved in translocations of a wide variety of substrates across cellular membranes. To understand the chemomechanical coupling mechanism as well as functional asymmetry in these systems, a quantitative description of how ABC transporters hydrolyze ATP is needed. Complementary to experimental approaches, computer simulations based on combined quantum mechanical and molecular mechanical (QM/MM) potentials have provided new insights into the catalytic mechanism in ABC transporters. Quantitatively reliable determination of the free energy requirement for enzymatic ATP hydrolysis, however, requires substantial statistical sampling on QM/MM potential. A case study shows that brute force sampling of ab initio QM/MM (AI/MM) potential energy surfaces is computationally impractical for enzyme simulations of ABC transporters. On the other hand, existing semiempirical QM/MM (SE/MM) methods, although affordable for free energy sampling, are unreliable for studying ATP hydrolysis. To close this gap, a multiscale QM/MM approach named reaction path–force matching (RP–FM) has been developed. In RP–FM, specific reaction parameters for a selected SE method are optimized against AI reference data along reaction paths by employing the force matching technique. The feasibility of the method is demonstrated for a proton transfer reaction in the gas phase and in solution. The RP–FM method may offer a general tool for simulating complex enzyme systems such as ABC transporters. PMID:27498639

  9. Identification of ABC Transporter Genes of Fusarium graminearum with Roles in Azole Tolerance and/or Virulence

    PubMed Central

    Döll, Katharina; Karlovsky, Petr; Deising, Holger B.; Wirsel, Stefan G. R.

    2013-01-01

    Fusarium graminearum is a plant pathogen infecting several important cereals, resulting in substantial yield losses and mycotoxin contamination of the grain. Triazole fungicides are used to control diseases caused by this fungus on a worldwide scale. Our previous microarray study indicated that 15 ABC transporter genes were transcriptionally upregulated in response to tebuconazole treatment. Here, we deleted four ABC transporter genes in two genetic backgrounds of F. graminearum representing the DON (deoxynivalenol) and the NIV (nivalenol) trichothecene chemotypes. Deletion of FgABC3 and FgABC4 belonging to group I of ABC-G and to group V of ABC-C subfamilies of ABC transporters, respectively, considerably increased the sensitivity to the class I sterol biosynthesis inhibitors triazoles and fenarimol. Such effects were specific since they did not occur with any other fungicide class tested. Assessing the contribution of the four ABC transporters to virulence of F. graminearum revealed that, irrespective of their chemotypes, deletion mutants of FgABC1 (ABC-C subfamily group V) and FgABC3 were impeded in virulence on wheat, barley and maize. Phylogenetic context and analyses of mycotoxin production suggests that FgABC3 may encode a transporter protecting the fungus from host-derived antifungal molecules. In contrast, FgABC1 may encode a transporter responsible for the secretion of fungal secondary metabolites alleviating defence of the host. Our results show that ABC transporters play important and diverse roles in both fungicide resistance and pathogenesis of F. graminearum. PMID:24244413

  10. The Yeast Plasma Membrane ATP Binding Cassette (ABC) Transporter Aus1

    PubMed Central

    Marek, Magdalena; Milles, Sigrid; Schreiber, Gabriele; Daleke, David L.; Dittmar, Gunnar; Herrmann, Andreas; Müller, Peter; Pomorski, Thomas Günther

    2011-01-01

    The ATP binding cassette (ABC) transporter Aus1 is expressed under anaerobic growth conditions at the plasma membrane of the yeast Saccharomyces cerevisiae and is required for sterol uptake. These observations suggest that Aus1 promotes the translocation of sterols across membranes, but the precise transport mechanism has yet to be identified. In this study, an extraction and purification procedure was developed to characterize the Aus1 transporter. The detergent-solubilized protein was able to bind and hydrolyze ATP. Mutagenesis of the conserved lysine to methionine in the Walker A motif abolished ATP hydrolysis. Likewise, ATP hydrolysis was inhibited by classical inhibitors of ABC transporters. Upon reconstitution into proteoliposomes, the ATPase activity of Aus1 was specifically stimulated by phosphatidylserine (PS) in a stereoselective manner. We also found that Aus1-dependent sterol uptake, but not Aus1 expression and trafficking to the plasma membrane, was affected by changes in cellular PS levels. These results suggest a direct interaction between Aus1 and PS that is critical for the activity of the transporter. PMID:21521689

  11. ABC transporters are involved in defense against permethrin insecticide in the malaria vector Anopheles stephensi.

    PubMed

    Epis, Sara; Porretta, Daniele; Mastrantonio, Valentina; Comandatore, Francesco; Sassera, Davide; Rossi, Paolo; Cafarchia, Claudia; Otranto, Domenico; Favia, Guido; Genchi, Claudio; Bandi, Claudio; Urbanelli, Sandra

    2014-07-29

    Proteins from the ABC family (ATP-binding cassette) represent the largest known group of efflux pumps, responsible for transporting specific molecules across lipid membranes in both prokaryotic and eukaryotic organisms. In arthropods they have been shown to play a role in insecticide defense/resistance. The presence of ABC transporters and their possible association with insecticide transport have not yet been investigated in the mosquito Anopheles stephensi, the major vector of human malaria in the Middle East and South Asian regions. Here we investigated the presence and role of ABCs in transport of permethrin insecticide in a susceptible strain of this mosquito species. To identify ABC transporter genes we obtained a transcriptome from untreated larvae of An. stephensi and then compared it with the annotated transcriptome of Anopheles gambiae. To analyse the association between ABC transporters and permethrin we conducted bioassays with permethrin alone and in combination with an ABC inhibitor, and then we investigated expression profiles of the identified genes in larvae exposed to permethrin. Bioassays showed an increased mortality of mosquitoes when permethrin was used in combination with the ABC-transporter inhibitor. Genes for ABC transporters were detected in the transcriptome, and five were selected (AnstABCB2, AnstABCB3, AnstABCB4, AnstABCmember6 and AnstABCG4). An increased expression in one of them (AnstABCG4) was observed in larvae exposed to the LD50 dose of permethrin. Contrary to what was found in other insect species, no up-regulation was observed in the AnstABCB genes. Our results show for the first time the involvement of ABC transporters in larval defense against permethrin in An. stephensi and, more in general, confirm the role of ABC transporters in insecticide defense. The differences observed with previous studies highlight the need of further research as, despite the growing number of studies on ABC transporters in insects, the

  12. Diversity of ABC transporter genes across the plant kingdom and their potential utility in biotechnology.

    PubMed

    Lane, Thomas S; Rempe, Caroline S; Davitt, Jack; Staton, Margaret E; Peng, Yanhui; Soltis, Douglas Edward; Melkonian, Michael; Deyholos, Michael; Leebens-Mack, James H; Chase, Mark; Rothfels, Carl J; Stevenson, Dennis; Graham, Sean W; Yu, Jun; Liu, Tao; Pires, J Chris; Edger, Patrick P; Zhang, Yong; Xie, Yinlong; Zhu, Ying; Carpenter, Eric; Wong, Gane Ka-Shu; Stewart, C Neal

    2016-05-31

    The ATP-binding cassette (ABC) transporter gene superfamily is ubiquitous among extant organisms and prominently represented in plants. ABC transporters act to transport compounds across cellular membranes and are involved in a diverse range of biological processes. Thus, the applicability to biotechnology is vast, including cancer resistance in humans, drug resistance among vertebrates, and herbicide and other xenobiotic resistance in plants. In addition, plants appear to harbor the highest diversity of ABC transporter genes compared with any other group of organisms. This study applied transcriptome analysis to survey the kingdom-wide ABC transporter diversity in plants and suggest biotechnology applications of this diversity. We utilized sequence similarity-based informatics techniques to infer the identity of ABC transporter gene candidates from 1295 phylogenetically-diverse plant transcriptomes. A total of 97,149 putative (approximately 25 % were full-length) ABC transporter gene members were identified; each RNA-Seq library (plant sample) had 88 ± 30 gene members. As expected, simpler organisms, such as algae, had fewer unique members than vascular land plants. Differences were also noted in the richness of certain ABC transporter subfamilies. Land plants had more unique ABCB, ABCC, and ABCG transporter gene members on average (p < 0.005), and green algae, red algae, and bryophytes had significantly more ABCF transporter gene members (p < 0.005). Ferns had significantly fewer ABCA transporter gene members than all other plant groups (p < 0.005). We present a transcriptomic overview of ABC transporter gene members across all major plant groups. An increase in the number of gene family members present in the ABCB, ABCC, and ABCD transporter subfamilies may indicate an expansion of the ABC transporter superfamily among green land plants, which include all crop species. The striking difference between the number of ABCA subfamily transporter

  13. Pharmacotherapy in pregnancy; effect of ABC and SLC transporters on drug transport across the placenta and fetal drug exposure.

    PubMed

    Staud, Frantisek; Cerveny, Lukas; Ceckova, Martina

    2012-11-01

    Pharmacotherapy during pregnancy is often inevitable for medical treatment of the mother, the fetus or both. The knowledge of drug transport across placenta is, therefore, an important topic to bear in mind when deciding treatment in pregnant women. Several drug transporters of the ABC and SLC families have been discovered in the placenta, such as P-glycoprotein, breast cancer resistance protein, or organic anion/cation transporters. It is thus evident that the passage of drugs across the placenta can no longer be predicted simply on the basis of their physical-chemical properties. Functional expression of placental drug transporters in the trophoblast and the possibility of drug-drug interactions must be considered to optimize pharmacotherapy during pregnancy. In this review we summarize current knowledge on the expression and function of ABC and SLC transporters in the trophoblast. Furthermore, we put this data into context with medical conditions that require maternal and/or fetal treatment during pregnancy, such as gestational diabetes, HIV infection, fetal arrhythmias and epilepsy. Proper understanding of the role of placental transporters should be of great interest not only to clinicians but also to pharmaceutical industry for future drug design and development to control the degree of fetal exposure.

  14. Interaction of ABC multidrug transporters with anticancer protein kinase inhibitors: substrates and/or inhibitors?

    PubMed

    Hegedus, Csilla; Ozvegy-Laczka, Csilla; Szakács, Gergely; Sarkadi, Balázs

    2009-05-01

    Protein kinase inhibitors (PKI) are becoming key agents in modern cancer chemotherapy, and combination of PKIs with classical chemotherapeutic drugs may help to overcome currently untreatable metastatic cancers. Since chemotherapy resistance is a recurrent problem, mechanisms of resistance should be clarified in order to help further drug development. Here we suggest that in addition to PKI resistance based on altered target structures, the active removal of these therapeutic agents by the MDR-ABC transporters should also be considered as a major cause of clinical resistance. We discuss the occurring systemic and cellular mechanisms, which may hamper PKI efficiency, and document the role of selected MDR-ABC transporters in these phenomena through their interactions with these anticancer agents. Moreover, we suggest that PKI interactions with ABC transporters may modulate overall drug metabolism, including the fate of diverse, chemically or target-wise unrelated drugs. These effects are based on multiple forms of MDR-ABC transporter interaction with PKIs, as these compounds may be both substrates and/or inhibitors of an ABC transporter. We propose that these interactions should be carefully considered in clinical application, and a combined MDR-ABC transporter and PKI effect may bring a major advantage in future drug development.

  15. Multidrug resistance in parasites: ABC transporters, P-glycoproteins and molecular modelling.

    PubMed

    Jones, P M; George, A M

    2005-04-30

    Parasitic diseases, caused by protozoa, helminths and arthropods, rank among the most important problems in human and veterinary medicine, and in agriculture, leading to debilitating sicknesses and loss of life. In the absence of vaccines and with the general failure of vector eradication programs, drugs are the main line of defence, but the newest drugs are being tracked by the emergence of resistance in parasites, sharing ominous parallels with multidrug resistance in bacterial pathogens. Any of a number of mechanisms will elicit a drug resistance phenotype in parasites, including: active efflux, reduced uptake, target modification, drug modification, drug sequestration, by-pass shunting, or substrate competition. The role of ABC transporters in parasitic multidrug resistance mechanisms is being subjected to more scrutiny, due in part to the established roles of certain ABC transporters in human diseases, and also to an increasing portfolio of ABC transporters from parasite genome sequencing projects. For example, over 100 ABC transporters have been identified in the Escherichia coli genome, but to date only about 65 in all parasitic genomes. Long established laboratory investigations are now being assisted by molecular biology, bioinformatics, and computational modelling, and it is in these areas that the role of ABC transporters in parasitic multidrug resistance mechanisms may be defined and put in perspective with that of other proteins. We discuss ABC transporters in parasites, and conclude with an example of molecular modelling that identifies a new interaction between the structural domains of a parasite P-glycoprotein.

  16. A Silent ABC Transporter Isolated from Streptomyces rochei F20 Induces Multidrug Resistance

    PubMed Central

    Fernández-Moreno, Miguel A.; Carbó, Lázaro; Cuesta, Trinidad; Vallín, Carlos; Malpartida, Francisco

    1998-01-01

    In the search for heterologous activators for actinorhodin production in Streptomyces lividans, 3.4 kb of DNA from Streptomyces rochei F20 (a streptothricin producer) were characterized. Subcloning experiments showed that the minimal DNA fragment required for activation was 0.4 kb in size. The activation is mediated by increasing the levels of transcription of the actII-ORF4 gene. Sequencing of the minimal activating fragment did not reveal any clues about its mechanism; nevertheless, it was shown to overlap the 3′ end of two convergent genes, one of whose translated products (ORF2) strongly resembles that of other genes belonging to the ABC transporter superfamily. Computer-assisted analysis of the 3.4-kb DNA sequence showed the 3′ terminus of an open reading frame (ORF), i.e., ORFA, and three complete ORFs (ORF1, ORF2, and ORFB). Searches in the databases with their respective gene products revealed similarities for ORF1 and ORF2 with ATP-binding proteins and transmembrane proteins, respectively, which are found in members of the ABC transporter superfamily. No similarities for ORFA and ORFB were found in the databases. Insertional inactivation of ORF1 and ORF2, their transcription analysis, and their cloning in heterologous hosts suggested that these genes were not expressed under our experimental conditions; however, cloning of ORF1 and ORF2 together (but not separately) under the control of an expressing promoter induced resistance to several chemically different drugs: oleandomycin, erythromycin, spiramycin, doxorubicin, and tetracycline. Thus, this genetic system, named msr, is a new bacterial multidrug ABC transporter. PMID:9696745

  17. Transcriptome-Based Identification of ABC Transporters in the Western Tarnished Plant Bug Lygus hesperus

    PubMed Central

    Hull, J. Joe; Chaney, Kendrick; Geib, Scott M.; Fabrick, Jeffrey A.; Brent, Colin S.; Walsh, Douglas; Lavine, Laura Corley

    2014-01-01

    ATP-binding cassette (ABC) transporters are a large superfamily of proteins that mediate diverse physiological functions by coupling ATP hydrolysis with substrate transport across lipid membranes. In insects, these proteins play roles in metabolism, development, eye pigmentation, and xenobiotic clearance. While ABC transporters have been extensively studied in vertebrates, less is known concerning this superfamily in insects, particularly hemipteran pests. We used RNA-Seq transcriptome sequencing to identify 65 putative ABC transporter sequences (including 36 full-length sequences) from the eight ABC subfamilies in the western tarnished plant bug (Lygus hesperus), a polyphagous agricultural pest. Phylogenetic analyses revealed clear orthologous relationships with ABC transporters linked to insecticide/xenobiotic clearance and indicated lineage specific expansion of the L. hesperus ABCG and ABCH subfamilies. The transcriptional profile of 13 LhABCs representative of the ABCA, ABCB, ABCC, ABCG, and ABCH subfamilies was examined across L. hesperus development and within sex-specific adult tissues. All of the transcripts were amplified from both reproductively immature and mature adults and all but LhABCA8 were expressed to some degree in eggs. Expression of LhABCA8 was spatially localized to the testis and temporally timed with male reproductive development, suggesting a potential role in sexual maturation and/or spermatozoa protection. Elevated expression of LhABCC5 in Malpighian tubules suggests a possible role in xenobiotic clearance. Our results provide the first transcriptome-wide analysis of ABC transporters in an agriculturally important hemipteran pest and, because ABC transporters are known to be important mediators of insecticidal resistance, will provide the basis for future biochemical and toxicological studies on the role of this protein family in insecticide resistance in Lygus species. PMID:25401762

  18. Mechanistic determinants of the directionality and energetics of active export by a heterodimeric ABC transporter

    DOE PAGES

    Grossmann, Nina; Vakkasoglu, Ahmet S.; Hulpke, Sabine; ...

    2014-11-07

    The ATP-binding cassette (ABC) transporter associated with antigen processing (TAP) participates in immune surveillance by moving proteasomal products into the endoplasmic reticulum (ER) lumen for major histocompatibility complex class I loading and cell surface presentation to cytotoxic T cells. Here we delineate the mechanistic basis for antigen translocation. Notably, TAP works as a molecular diode, translocating peptide substrates against the gradient in a strict unidirectional way. We reveal the importance of the D-loop at the dimer interface of the two nucleotide-binding domains (NBDs) in coupling substrate translocation with ATP hydrolysis and defining transport vectoriality. Substitution of the converved aspartate, whichmore » coordinates the ATP-binding site, decreases NBD dimerization affinity and turns the unidirectional primary active pump into a passive bidirectional nucleotide-gated facilitator. Thus, ATP hydrolysis is not required for translocation per se, but is essential for both active and unidirectional transport. As a result, our data provide detailed mechanistic insight into how heterodimeric ABC exporters operate.« less

  19. The ABC of Biofilm Drug Tolerance: the MerR-Like Regulator BrlR Is an Activator of ABC Transport Systems, with PA1874-77 Contributing to the Tolerance of Pseudomonas aeruginosa Biofilms to Tobramycin.

    PubMed

    Poudyal, Bandita; Sauer, Karin

    2018-02-01

    A hallmark of biofilms is their tolerance to killing by antimicrobial agents. In Pseudomonas aeruginosa , biofilm drug tolerance requires the c-di-GMP-responsive MerR transcriptional regulator BrlR. However, the mechanism by which BrlR mediates biofilm drug tolerance has not been elucidated. Here, we demonstrate that BrlR activates the expression of at least 7 ABC transport systems, including the PA1874-PA1875-PA1876-PA1877 (PA1874-77) operon, with chromatin immunoprecipitation and DNA binding assays confirming BrlR binding to the promoter region of PA1874-77. Insertional inactivation of the 7 ABC transport systems rendered P. aeruginosa PAO1 biofilms susceptible to tobramycin or norfloxacin. Susceptibility was linked to drug accumulation, with BrlR contributing to norfloxacin accumulation in a manner dependent on multidrug efflux pumps and the PA1874-77 ABC transport system. Inactivation of the respective ABC transport system, furthermore, eliminated the recalcitrance of biofilms to killing by tobramycin but not norfloxacin, indicating that drug accumulation is not linked to biofilm drug tolerance. Our findings indicate for the first time that BrlR, a MerR-type transcriptional activator, activates genes encoding several ABC transport systems, in addition to multiple multidrug efflux pump genes. Moreover, our data confirm a BrlR target contributing to drug tolerance, likely countering the prevailing dogma that biofilm tolerance arises from a multiplicity of factors. Copyright © 2018 American Society for Microbiology.

  20. ABC Transporter Genes and Risk of Type 2 Diabetes

    PubMed Central

    Schou, Jesper; Tybjærg-Hansen, Anne; Møller, Holger J.; Nordestgaard, Børge G.; Frikke-Schmidt, Ruth

    2012-01-01

    OBJECTIVE Alterations of pancreatic β-cell cholesterol content may contribute to β-cell dysfunction. Two important determinants of intracellular cholesterol content are the ATP-binding cassette (ABC) transporters A1 (ABCA1) and -G1 (ABCG1). Whether genetic variation in ABCA1 and ABCG1 predicts risk of type 2 diabetes in the general population is unknown. RESEARCH DESIGN AND METHODS We tested whether genetic variation in the promoter and coding regions of ABCA1 and ABCG1 predicted risk of type 2 diabetes in the general population. Twenty-seven variants, identified by previous resequencing of both genes, were genotyped in the Copenhagen City Heart Study (CCHS) (n = 10,185). Two loss-of-function mutations (ABCA1 N1800H and ABCG1 g.-376C>T) (n = 322) and a common variant (ABCG1 g.-530A>G) were further genotyped in the Copenhagen General Population Study (CGPS) (n = 30,415). RESULTS Only one of the variants examined, ABCG1 g.-530A>G, predicted a decreased risk of type 2 diabetes in the CCHS (P for trend = 0.05). Furthermore, when validated in the CGPS or in the CCHS and CGPS combined (n = 40,600), neither the two loss-of-function mutations (ABCA1 N1800H, ABCG1 g.-376C>T) nor ABCG1 g.-530A>G were associated with type 2 diabetes (P values >0.57 and >0.30, respectively). CONCLUSIONS Genetic variations in ABCA1 and ABCG1 were not associated with increased risk of type 2 diabetes in the general population. These data were obtained in general population samples harboring the largest number of heterozygotes for loss-of-function mutations in ABCA1 and ABCG1. PMID:23139370

  1. A PhoPQ-Regulated ABC Transporter System Exports Tetracycline in Pseudomonas aeruginosa.

    PubMed

    Chen, Lin; Duan, Kangmin

    2016-05-01

    Pseudomonas aeruginosa is an important human pathogen whose infections are difficult to treat due to its high intrinsic resistance to many antibiotics. Here, we show that the disruption of PA4456, encoding the ATP binding component of a putative ATP-binding cassette (ABC) transporter, increased the bacterium's susceptible to tetracycline and other antibiotics or toxic chemicals. Fluorescence spectroscopy and antibiotic accumulation tests showed that the interruption of the ABC transporter caused increased intracellular accumulation of tetracycline, demonstrating a role of the ABC transporter in tetracycline expulsion. Site-directed mutagenesis proved that the conserved residues of E170 in the Walker B motif and H203 in the H-loop, which are important for ATP hydrolysis, were essential for the function of PA4456. Through a genome-wide search, the PhoPQ two-component system was identified as a regulator of the computationally predicted PA4456-4452 operon that encodes the ABC transporter system. A >5-fold increase of the expression of this operon was observed in the phoQ mutant. The results obtained also show that the expression of the phzA1B1C1D1E1 operon and the production of pyocyanin were significantly higher in the ABC transporter mutant, signifying a connection between the ABC transporter and pyocyanin production. These results indicated that the PhoPQ-regulated ABC transporter is associated with intrinsic resistance to antibiotics and other adverse compounds in P. aeruginosa, probably by extruding them out of the cell. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  2. Transcriptomic insights on the ABC transporter gene family in the salmon louse Caligus rogercresseyi.

    PubMed

    Valenzuela-Muñoz, Valentina; Sturm, Armin; Gallardo-Escárate, Cristian

    2015-04-09

    ATP-binding cassette (ABC) protein family encode for membrane proteins involved in the transport of various biomolecules through the cellular membrane. These proteins have been identified in all taxa and present important physiological functions, including the process of insecticide detoxification in arthropods. For that reason the ectoparasite Caligus rogercresseyi represents a model species for understanding the molecular underpinnings involved in insecticide drug resistance. llumina sequencing was performed using sea lice exposed to 2 and 3 ppb of deltamethrin and azamethiphos. Contigs obtained from de novo assembly were annotated by Blastx. RNA-Seq analysis was performed and validated by qPCR analysis. From the transcriptome database of C. rogercresseyi, 57 putative members of ABC protein sequences were identified and phylogenetically classified into the eight subfamilies described for ABC transporters in arthropods. Transcriptomic profiles for ABC proteins subfamilies were evaluated throughout C. rogercresseyi development. Moreover, RNA-Seq analysis was performed for adult male and female salmon lice exposed to the delousing drugs azamethiphos and deltamethrin. High transcript levels of the ABCB and ABCC subfamilies were evidenced. Furthermore, SNPs mining was carried out for the ABC proteins sequences, revealing pivotal genomic information. The present study gives a comprehensive transcriptome analysis of ABC proteins from C. rogercresseyi, providing relevant information about transporter roles during ontogeny and in relation to delousing drug responses in salmon lice. This genomic information represents a valuable tool for pest management in the Chilean salmon aquaculture industry.

  3. Transcriptome-based identification of ABC transporters in the western tarnished plant bug lygus hesperus

    USDA-ARS?s Scientific Manuscript database

    ATP-binding cassette (ABC) transporters are a large superfamily of proteins that mediate diverse physiological functions by coupling ATP hydrolysis with substrate transport across lipid membranes. In insects, these proteins play roles in metabolism, development, eye pigmentation, and xenobiotic cle...

  4. Harnessing Drug Resistance: Using ABC Transporter Proteins To Target Cancer Cells

    PubMed Central

    Leitner, Heather M.; Kachadourian, Remy; Day, Brian J.

    2007-01-01

    The ATP-binding cassette (ABC) class of proteins is one of the most functionally diverse transporter families found in biological systems. Although the abundance of ABC proteins varies between species, they are highly conserved in sequence and often demonstrate similar functions across prokaryotic and eukaryotic organisms. Beginning with a brief summary of the events leading to our present day knowledge of ABC transporters, the purpose of this review is to discuss the potential for utilizing ABC transporters as a means for cellular glutathione (GSH) modulation. GSH is one of the most abundant thiol antioxidants in cells. It is involved in cellular division, protein and DNA synthesis, maintenance of cellular redox status and xenobiotic metabolism. Cellular GSH levels are often altered in many disease states including cancer. Over the past two decades there has been considerable emphasis on methods to sensitize cancer cells to chemotherapeutics and ionization radiation therapy by GSH depletion. We contend that ABC transporters, particularly multi-drug resistant proteins (MRPs), may be used as therapeutic targets for applications aimed at modulation of GSH levels. This review will emphasize MRP-mediated modulation of intracellular GSH levels as a potential alternative and adjunctive approach for cancer therapy. PMID:17585883

  5. ATP binding cassette (ABC) transporters: expression and clinical value in glioblastoma.

    PubMed

    Dréan, Antonin; Rosenberg, Shai; Lejeune, François-Xavier; Goli, Larissa; Nadaradjane, Aravindan Arun; Guehennec, Jérémy; Schmitt, Charlotte; Verreault, Maïté; Bielle, Franck; Mokhtari, Karima; Sanson, Marc; Carpentier, Alexandre; Delattre, Jean-Yves; Idbaih, Ahmed

    2018-03-08

    ATP-binding cassette transporters (ABC transporters) regulate traffic of multiple compounds, including chemotherapeutic agents, through biological membranes. They are expressed by multiple cell types and have been implicated in the drug resistance of some cancer cells. Despite significant research in ABC transporters in the context of many diseases, little is known about their expression and clinical value in glioblastoma (GBM). We analyzed expression of 49 ABC transporters in both commercial and patient-derived GBM cell lines as well as from 51 human GBM tumor biopsies. Using The Cancer Genome Atlas (TCGA) cohort as a training dataset and our cohort as a validation dataset, we also investigated the prognostic value of these ABC transporters in newly diagnosed GBM patients, treated with the standard of care. In contrast to commercial GBM cell lines, GBM-patient derived cell lines (PDCL), grown as neurospheres in a serum-free medium, express ABC transporters similarly to parental tumors. Serum appeared to slightly increase resistance to temozolomide correlating with a tendency for an increased expression of ABCB1. Some differences were observed mainly due to expression of ABC transporters by microenvironmental cells. Together, our data suggest that the efficacy of chemotherapeutic agents may be misestimated in vitro if they are the targets of efflux pumps whose expression can be modulated by serum. Interestingly, several ABC transporters have prognostic value in the TCGA dataset. In our cohort of 51 GBM patients treated with radiation therapy with concurrent and adjuvant temozolomide, ABCA13 overexpression is associated with a decreased progression free survival in univariate (p < 0.01) and multivariate analyses including MGMT promoter methylation (p = 0.05) suggesting reduced sensitivity to temozolomide in ABCA13 overexpressing GBM. Expression of ABC transporters is: (i) detected in GBM and microenvironmental cells and (ii) better reproduced in GBM

  6. ABC transporter activity linked to radiation resistance and molecular subtype in pediatric medulloblastoma

    PubMed Central

    2013-01-01

    Background Resistance to radiation treatment remains a major clinical problem for patients with brain cancer. Medulloblastoma is the most common malignant brain tumor of childhood, and occurs in the cerebellum. Though radiation treatment has been critical in increasing survival rates in recent decades, the presence of resistant cells in a substantial number of medulloblastoma patients leads to relapse and death. Methods Using the established medulloblastoma cell lines UW228 and Daoy, we developed a novel model system to enrich for and study radiation tolerant cells early after radiation exposure. Using fluorescence-activated cell sorting, dead cells and cells that had initiated apoptosis were removed, allowing surviving cells to be investigated before extensive proliferation took place. Results Isolated surviving cells were tumorigenic in vivo and displayed elevated levels of ABCG2, an ABC transporter linked to stem cell behavior and drug resistance. Further investigation showed another family member, ABCA1, was also elevated in surviving cells in these lines, as well as in early passage cultures from pediatric medulloblastoma patients. We discovered that the multi-ABC transporter inhibitors verapamil and reserpine sensitized cells from particular patients to radiation, suggesting that ABC transporters have a functional role in cellular radiation protection. Additionally, verapamil had an intrinsic anti-proliferative effect, with transient exposure in vitro slowing subsequent in vivo tumor formation. When expression of key ABC transporter genes was assessed in medulloblastoma tissue from 34 patients, levels were frequently elevated compared with normal cerebellum. Analysis of microarray data from independent cohorts (n = 428 patients) showed expression of a number of ABC transporters to be strongly correlated with certain medulloblastoma subtypes, which in turn are associated with clinical outcome. Conclusions ABC transporter inhibitors are already being

  7. ABCdb: an online resource for ABC transporter repertories from sequenced archaeal and bacterial genomes.

    PubMed

    Fichant, Gwennaele; Basse, Marie-Jeanne; Quentin, Yves

    2006-03-01

    The ATP-binding cassette (ABC) transporters are one of the major classes of active transporters. They are widespread in archaea, bacteria, and eukaryota, indicating that they have arisen early in evolution. They are involved in many essential physiological processes, but the majority import or export a wide variety of compounds across cellular membranes. These systems share a common architecture composed of four (exporters) or five (importers) domains. To identify and reconstruct functional ABC transporters encoded by archaeal and bacterial genomes, we have developed a bioinformatic strategy. Cross-reference to the transport classification system is used to predict the type of compound transported. A high quality of annotation is achieved by manual verification of the predictions. However, in order to face the rapid increase in the number of published genomes, we also include analyses of genomes issuing directly from the automated strategy. Querying the database (http://www-abcdb.biotoul.fr) allows to easily retrieve ABC transporter repertories and related data. Additional query tools have been developed for the analysis of the ABC family from both functional and evolutionary perspectives.

  8. Antibiotic Resistance Mediated by the MacB ABC Transporter Family: A Structural and Functional Perspective

    PubMed Central

    Greene, Nicholas P.; Kaplan, Elise; Crow, Allister; Koronakis, Vassilis

    2018-01-01

    The MacB ABC transporter forms a tripartite efflux pump with the MacA adaptor protein and TolC outer membrane exit duct to expel antibiotics and export virulence factors from Gram-negative bacteria. Here, we review recent structural and functional data on MacB and its homologs. MacB has a fold that is distinct from other structurally characterized ABC transporters and uses a unique molecular mechanism termed mechanotransmission. Unlike other bacterial ABC transporters, MacB does not transport substrates across the inner membrane in which it is based, but instead couples cytoplasmic ATP hydrolysis with transmembrane conformational changes that are used to perform work in the extra-cytoplasmic space. In the MacAB-TolC tripartite pump, mechanotransmission drives efflux of antibiotics and export of a protein toxin from the periplasmic space via the TolC exit duct. Homologous tripartite systems from pathogenic bacteria similarly export protein-like signaling molecules, virulence factors and siderophores. In addition, many MacB-like ABC transporters do not form tripartite pumps, but instead operate in diverse cellular processes including antibiotic sensing, cell division and lipoprotein trafficking. PMID:29892271

  9. Antibiotic Resistance Mediated by the MacB ABC Transporter Family: A Structural and Functional Perspective.

    PubMed

    Greene, Nicholas P; Kaplan, Elise; Crow, Allister; Koronakis, Vassilis

    2018-01-01

    The MacB ABC transporter forms a tripartite efflux pump with the MacA adaptor protein and TolC outer membrane exit duct to expel antibiotics and export virulence factors from Gram-negative bacteria. Here, we review recent structural and functional data on MacB and its homologs. MacB has a fold that is distinct from other structurally characterized ABC transporters and uses a unique molecular mechanism termed mechanotransmission. Unlike other bacterial ABC transporters, MacB does not transport substrates across the inner membrane in which it is based, but instead couples cytoplasmic ATP hydrolysis with transmembrane conformational changes that are used to perform work in the extra-cytoplasmic space. In the MacAB-TolC tripartite pump, mechanotransmission drives efflux of antibiotics and export of a protein toxin from the periplasmic space via the TolC exit duct. Homologous tripartite systems from pathogenic bacteria similarly export protein-like signaling molecules, virulence factors and siderophores. In addition, many MacB-like ABC transporters do not form tripartite pumps, but instead operate in diverse cellular processes including antibiotic sensing, cell division and lipoprotein trafficking.

  10. Detergent-free purification of ABC (ATP-binding-cassette) transporters.

    PubMed

    Gulati, Sonali; Jamshad, Mohammed; Knowles, Timothy J; Morrison, Kerrie A; Downing, Rebecca; Cant, Natasha; Collins, Richard; Koenderink, Jan B; Ford, Robert C; Overduin, Michael; Kerr, Ian D; Dafforn, Timothy R; Rothnie, Alice J

    2014-07-15

    ABC (ATP-binding-cassette) transporters carry out many vital functions and are involved in numerous diseases, but study of the structure and function of these proteins is often hampered by their large size and membrane location. Membrane protein purification usually utilizes detergents to solubilize the protein from the membrane, effectively removing it from its native lipid environment. Subsequently, lipids have to be added back and detergent removed to reconstitute the protein into a lipid bilayer. In the present study, we present the application of a new methodology for the extraction and purification of ABC transporters without the use of detergent, instead, using a copolymer, SMA (polystyrene-co-maleic acid). SMA inserts into a bilayer and assembles into discrete particles, essentially solubilizing the membrane into small discs of bilayer encircled by a polymer, termed SMALPs (SMA lipid particles). We show that this polymer can extract several eukaryotic ABC transporters, P-glycoprotein (ABCB1), MRP1 (multidrug-resistance protein 1; ABCC1), MRP4 (ABCC4), ABCG2 and CFTR (cystic fibrosis transmembrane conductance regulator; ABCC7), from a range of different expression systems. The SMALP-encapsulated ABC transporters can be purified by affinity chromatography, and are able to bind ligands comparably with those in native membranes or detergent micelles. A greater degree of purity and enhanced stability is seen compared with detergent solubilization. The present study demonstrates that eukaryotic ABC transporters can be extracted and purified without ever being removed from their lipid bilayer environment, opening up a wide range of possibilities for the future study of their structure and function.

  11. Surface charge-specific interactions between polymer nanoparticles and ABC transporters in Caco-2 cells

    NASA Astrophysics Data System (ADS)

    Bhattacharjee, Sourav; van Opstal, Edward J.; Alink, Gerrit M.; Marcelis, Antonius T. M.; Zuilhof, Han; Rietjens, Ivonne M. C. M.

    2013-06-01

    The surface charge-dependent transport of polymeric nanoparticles (PNPs) across Caco-2 monolayers grown on transwell culture systems as an in vitro model for intestinal transport was tested. The transport of well-characterized, monodisperse, and fluorescent tri-block copolymer nanoparticles (TCNPs/size 45 nm) and polystyrene nanoparticles (PSNPs/size 50 nm), with different surface charges (positive and negative), was quantified. The positive PNPs showed a higher intracellular uptake and flux across the Caco-2 monolayers than the negative PNPs. Multidrug resistance/P-glycoprotein (MDR1/P-gp), a specific ATP-binding cassette (ABC) transporter, was found to play a major role in the cellular efflux of positive PNPs, whereas the multidrug resistance protein 1 took part in the efflux of negative PNPs from Caco-2 cells. The positive PNPs also caused an increased cellular uptake and apical to basolateral transport of the carcinogen PhIP across the Caco-2 monolayer. The flavonoid quercetin, which is known to interact with ABC transporters, promoted the intracellular uptake of different PNPs and interfered with the normal distribution patterns of PNPs in the transwell system. These results indicate that PNPs display surface charge-specific interactions with ABC transporters and can even affect the bioavailability of toxic food-borne compounds (like pro-carcinogens).

  12. Sensitive and Specific Fluorescent Probes for Functional Analysis of the Three Major Types of Mammalian ABC Transporters

    PubMed Central

    Lebedeva, Irina V.; Pande, Praveen; Patton, Wayne F.

    2011-01-01

    An underlying mechanism for multi drug resistance (MDR) is up-regulation of the transmembrane ATP-binding cassette (ABC) transporter proteins. ABC transporters also determine the general fate and effect of pharmaceutical agents in the body. The three major types of ABC transporters are MDR1 (P-gp, P-glycoprotein, ABCB1), MRP1/2 (ABCC1/2) and BCRP/MXR (ABCG2) proteins. Flow cytometry (FCM) allows determination of the functional expression levels of ABC transporters in live cells, but most dyes used as indicators (rhodamine 123, DiOC2(3), calcein-AM) have limited applicability as they do not detect all three major types of ABC transporters. Dyes with broad coverage (such as doxorubicin, daunorubicin and mitoxantrone) lack sensitivity due to overall dimness and thus may yield a significant percentage of false negative results. We describe two novel fluorescent probes that are substrates for all three common types of ABC transporters and can serve as indicators of MDR in flow cytometry assays using live cells. The probes exhibit fast internalization, favorable uptake/efflux kinetics and high sensitivity of MDR detection, as established by multidrug resistance activity factor (MAF) values and Kolmogorov-Smirnov statistical analysis. Used in combination with general or specific inhibitors of ABC transporters, both dyes readily identify functional efflux and are capable of detecting small levels of efflux as well as defining the type of multidrug resistance. The assay can be applied to the screening of putative modulators of ABC transporters, facilitating rapid, reproducible, specific and relatively simple functional detection of ABC transporter activity, and ready implementation on widely available instruments. PMID:21799851

  13. ABC Transporters and Isothiocyanates: Potential for Pharmacokinetic Diet–Drug Interactions

    PubMed Central

    Telang, Urvi; Ji, Yan; Morris, Marilyn E.

    2013-01-01

    Isothiocyanates, a class of anti-cancer agents, are derived from cruciferous vegetables such as broccoli, cabbage and watercress, and have demonstrated chemopreventive activity in a number of cancer models and epidemiologic studies. Due to public interest in cancer prevention and alternative therapies in cancer, the consumption of herbal supplements and vegetables containing these compounds is widespread and increasing. Isothiocyanates interact with ATP-binding cassette (ABC) efflux transporters such as P-glycoprotein, MRP1, MRP2 and BCRP, and may influence the pharmacokinetics of substrates of these transporters. This review discusses the pharmacokinetic properties of isothiocyanates, their interactions with ABC transporters, and presents some data describing the potential for isothiocyanate-mediated diet–drug interactions. PMID:19623673

  14. Multiple ABC transporters are involved in the acquisition of petrobactin in Bacillus anthracis

    PubMed Central

    Dixon, Shandee D.; Janes, Brian K.; Bourgis, Alexandra; Carlson, Paul E.; Hanna, Philip C.

    2012-01-01

    Summary In Bacillus anthracis the siderophore petrobactin is vital for iron acquisition and virulence. The petrobactin-binding receptor FpuA is required for these processes. Here additional components of petrobactin reacquisition are described. To identify these proteins, mutants of candidate permease and ATPase genes were generated allowing for characterization of multiple petrobactin ATP-binding cassette (ABC)-import systems. Either of two distinct permeases, FpuB or FatCD, are required for iron acquisition and play redundant roles in petrobactin transport. A mutant strain lacking both permeases, ΔfpuBΔfatCD, was incapable of using petrobactin as an iron source and exhibited attenuated virulence in a murine model of inhalational anthrax infection. ATPase mutants were generated in either of the permease mutant backgrounds to identify the ATPase(s) interacting with each individual permease channel. Mutants lacking the FpuB permease and FatE ATPase (ΔfpuBΔfatE) and a mutant lacking the distinct ATPases FpuC and FpuD generated in the ΔfatCD background (ΔfatCDΔfpuCΔfpuD) displayed phenotypic characteristics of a mutant deficient in petrobactin import. A mutant lacking all three of the identified ATPases (ΔfatEΔfpuCΔfpuD) exhibited the same growth defect in iron-depleted conditions. Taken together, these results provide the first description of the permease and ATPase proteins required for the import of petrobactin in B. anthracis. PMID:22429808

  15. Temporal dynamics of the ABC transporter response to insecticide treatment: insights from the malaria vector Anopheles stephensi

    NASA Astrophysics Data System (ADS)

    Epis, Sara; Porretta, Daniele; Mastrantonio, Valentina; Urbanelli, Sandra; Sassera, Davide; De Marco, Leone; Mereghetti, Valeria; Montagna, Matteo; Ricci, Irene; Favia, Guido; Bandi, Claudio

    2014-12-01

    In insects, ABC transporters have been shown to contribute to defence/resistance to insecticides by reducing toxic concentrations in cells/tissues. Despite the extensive studies about this detoxifying mechanism, the temporal patterns of ABC transporter activation have been poorly investigated. Using the malaria vector Anopheles stephensi as a study system, we investigated the expression profile of ABC genes belonging to different subfamilies in permethrin-treated larvae at different time points (30 min to 48 h). Our results showed that the expression of ABCB and ABCG subfamily genes was upregulated at 1 h after treatment, with the highest expression observed at 6 h. Therefore, future investigations on the temporal dynamics of ABC gene expression will allow a better implementation of insecticide treatment regimens, including the use of specific inhibitors of ABC efflux pumps.

  16. Nucleotide-induced conformational dynamics in ABC transporters from structure-based coarse grained modelling.

    NASA Astrophysics Data System (ADS)

    Flechsig, Holger

    2016-02-01

    ATP-binding cassette (ABC) transporters are integral membrane proteins which mediate the exchange of diverse substrates across membranes powered by ATP molecules. Our understanding of their activity is still hampered since the conformational dynamics underlying the operation of such proteins cannot yet be resolved in detailed molecular dynamics studies. Here a coarse grained model which allows to mimic binding of nucleotides and follow subsequent conformational motions of full-length transporter structures in computer simulations is proposed and implemented. To justify its explanatory quality, the model is first applied to the maltose transporter system for which multiple conformations are known and we find that the model predictions agree remarkably well with the experimental data. For the MalK subunit the switching from open to the closed dimer configuration upon ATP binding is reproduced and, moreover, for the full-length maltose transporter, progression from inward-facing to the outward-facing state is correctly obtained. For the heme transporter HmuUV, for which only the free structure could yet be determined, the model was then applied to predict nucleotide-induced conformational motions. Upon binding of ATP-mimicking ligands the structure changed from a conformation in which the nucleotide-binding domains formed an open shape, to a conformation in which they were found in tight contact, while, at the same time, a pronounced rotation of the transmembrane domains was observed. This finding is supported by normal mode analysis, and, comparison with structural data of the homologous vitamin B12 transporter BtuCD suggests that the observed rotation mechanism may contribute a common functional aspect for this class of ABC transporters. Although in HmuuV noticeable rearrangement of essential transmembrane helices was detected, there are no indications from our simulations that ATP binding alone may facilitate propagation of substrate molecules in this transporter

  17. Predictive Structure and Topology of Peroxisomal ATP-Binding Cassette (ABC) Transporters

    PubMed Central

    Andreoletti, Pierre; Raas, Quentin; Gondcaille, Catherine; Cherkaoui-Malki, Mustapha; Trompier, Doriane; Savary, Stéphane

    2017-01-01

    The peroxisomal ATP-binding Cassette (ABC) transporters, which are called ABCD1, ABCD2 and ABCD3, are transmembrane proteins involved in the transport of various lipids that allow their degradation inside the organelle. Defective ABCD1 leads to the accumulation of very long-chain fatty acids and is associated with a complex and severe neurodegenerative disorder called X-linked adrenoleukodystrophy (X-ALD). Although the nucleotide-binding domain is highly conserved and characterized within the ABC transporters family, solid data are missing for the transmembrane domain (TMD) of ABCD proteins. The lack of a clear consensus on the secondary and tertiary structure of the TMDs weakens any structure-function hypothesis based on the very diverse ABCD1 mutations found in X-ALD patients. Therefore, we first reinvestigated thoroughly the structure-function data available and performed refined alignments of ABCD protein sequences. Based on the 2.85  Å resolution crystal structure of the mitochondrial ABC transporter ABCB10, here we propose a structural model of peroxisomal ABCD proteins that specifies the position of the transmembrane and coupling helices, and highlight functional motifs and putative important amino acid residues. PMID:28737695

  18. The Role of the Photoreceptor ABC Transporter ABCA4 in Lipid Transport and Stargardt Macular Degeneration

    PubMed Central

    Molday, Robert S.; Zhong, Ming; Quazi, Faraz

    2009-01-01

    ABCA4 is a member of the ABCA subfamily of ATP binding cassette (ABC) transporters that is expressed in rod and cone photoreceptors of the vertebrate retina. ABCA4, also known as the Rim protein and ABCR, is a large 2273 amino acid glycoprotein organized as two tandem halves, each containing a single membrane spanning segment followed sequentially by a large exocytoplasmic domain, a multispanning membrane domain and a nucleotide binding domain. Over 500 mutations in the gene encoding ABCA4 are associated with a spectrum of related autosomal recessive retinal degenerative diseases including Stargardt macular degeneration, cone-rod dystrophy and a subset of retinitis pigmentosa. Biochemical studies on the purified ABCA4 together with analysis of abca4 knockout mice and patients with Stargardt disease have implicated ABCA4 as a retinylidene-phosphatidylethanolamine transporter that facilitates the removal of potentially reactive retinal derivatives from photoreceptors following photoexcitation. Knowledge of the genetic and molecular basis for ABCA4 related retinal degenerative diseases is being used to develop rationale therapeutic treatments for this set of disorders. PMID:19230850

  19. Alzheimer’s and ABC transporters - new opportunities for diagnostics and treatment

    PubMed Central

    Pahnke, Jens; Langer, Oliver; Krohn, Markus

    2014-01-01

    Much has been said about the increasing number of demented patients and the main risk factor ‘age’. Frustratingly, we do not know the precise pattern and all modulating factors that provoke the pathologic changes in the brains of affected elderly. We have to diagnose early to be able to stop the progression of diseases that irreversibly destroy brain substance. Familiar AD cases have mislead some researchers for almost 20 years, which has unfortunately narrowed the scientific understanding and has, thus, lead to insufficient funding of independent approaches. Therefore, basic researchers hardly have been able to develop causative treatments and clinicians still do not have access to prognostic and early diagnostic tools. During the recent years it became clear that insufficient Aβ export, physiologically facilitated by the ABC transporter superfamily at the brain’s barriers, plays a fundamental role in disease initiation and progression. Furthermore, export mechanisms that are deficient in affected elderly are new targets for activation and, thus, treatment, but ideally also for prevention. In sporadic AD disturbed clearance of β-amyloid from the brain is so far the most important factor for its accumulation in the parenchyma and vessel walls. Here, we review findings about the contribution of ABC transporters and of the perivascular drainage/glymphatic system on β-amyloid clearance. We highlight their potential value for innovative early diagnostics using PET and describe recently described, effective ABC transporter-targeting agents as potential causative treatment for neurodegenerative proteopathies/dementias. PMID:24746857

  20. Alzheimer's and ABC transporters--new opportunities for diagnostics and treatment.

    PubMed

    Pahnke, Jens; Langer, Oliver; Krohn, Markus

    2014-12-01

    Much has been said about the increasing number of demented patients and the main risk factor 'age'. Frustratingly, we do not know the precise pattern and all modulating factors that provoke the pathologic changes in the brains of affected elderly. We have to diagnose early to be able to stop the progression of diseases that irreversibly destroy brain substance. Familiar AD cases have mislead some researchers for almost 20 years, which has unfortunately narrowed the scientific understanding and has, thus, lead to insufficient funding of independent approaches. Therefore, basic researchers hardly have been able to develop causative treatments and clinicians still do not have access to prognostic and early diagnostic tools. During the recent years it became clear that insufficient Aβ export, physiologically facilitated by the ABC transporter superfamily at the brain's barriers, plays a fundamental role in disease initiation and progression. Furthermore, export mechanisms that are deficient in affected elderly are new targets for activation and, thus, treatment, but ideally also for prevention. In sporadic AD disturbed clearance of β-amyloid from the brain is so far the most important factor for its accumulation in the parenchyma and vessel walls. Here, we review findings about the contribution of ABC transporters and of the perivascular drainage/glymphatic system on β-amyloid clearance. We highlight their potential value for innovative early diagnostics using PET and describe recently described, effective ABC transporter-targeting agents as potential causative treatment for neurodegenerative proteopathies/dementias. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Characterization of SiaA, a streptococcal heme-binding protein associated with a heme ABC transport system.

    PubMed

    Sook, Brian R; Block, Darci R; Sumithran, Suganya; Montañez, Griselle E; Rodgers, Kenton R; Dawson, John H; Eichenbaum, Zehava; Dixon, Dabney W

    2008-02-26

    Many pathogenic bacteria require heme and obtain it from their environment. Heme transverses the cytoplasmic membrane via an ATP binding cassette (ABC) pathway. Although a number of heme ABC transport systems have been described in pathogenic bacteria, there is as yet little biophysical characterization of the proteins in these systems. The sia (hts) gene cluster encodes a heme ABC transporter in the Gram positive Streptococcus pyogenes. The lipoprotein-anchored heme binding protein (HBP) of this transporter is SiaA (HtsA). In the current study, resonance Raman (rR), magnetic circular dichroism (MCD), and nuclear magnetic resonance (NMR) spectroscopies were used to determine the coordination state and spin state of both the ferric and ferrous forms of this protein. Identifiers from these techniques suggest that the heme is six-coordinate and low-spin in both oxidation states of the protein, with methionine and histidine as axial ligands. SiaA has a pKa of 9.7 +/- 0.1, attributed to deprotonation of the axial histidine. Guanidinium titration studies show that the ferric state is less stable than the ferrous state, with DeltaG(H2O) values for the oxidized and reduced proteins of 7.3 +/- 0.8 and 16.0 +/- 3.6 kcal mol-1, respectively. The reductive and oxidative midpoint potentials determined via spectroelectrochemistry are 83 +/- 3 and 64 +/- 3 mV, respectively; the irreversibility of heme reduction suggests that redox cycling of the heme is coupled to a kinetically sluggish change in structure or conformation. The biophysical characterization described herein will significantly advance our understanding of structure-function relationships in HBP.

  2. 40 CFR Table 3 to Subpart II of... - Summary of Recordkeeping and Reporting Requirements abc

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... abc Requirement All Opts. Rec Rep Option 1 Rec Rep Option 2 Rec Rep Option 3 Rec Rep Notification (§ 63.9(a)-(d)) X X Implementation plan (§ 63.787(b)) d X X Volume of coating applied at unaffected major sources (§ 63.781(b)) X Volume of each low-usage-exempt coating applied at affected sources (§ 63...

  3. 40 CFR Table 3 to Subpart II of... - Summary of Recordkeeping and Reporting Requirements abc

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... abc Requirement All Opts. Rec Rep Option 1 Rec Rep Option 2 Rec Rep Option 3 Rec Rep Notification (§ 63.9(a)-(d)) X X Implementation plan (§ 63.787(b)) d X X Volume of coating applied at unaffected major sources (§ 63.781(b)) X Volume of each low-usage-exempt coating applied at affected sources (§ 63...

  4. 40 CFR Table 3 to Subpart II of... - Summary of Recordkeeping and Reporting Requirements abc

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... abc Requirement All Opts. Rec Rep Option 1 Rec Rep Option 2 Rec Rep Option 3 Rec Rep Notification (§ 63.9(a)-(d)) X X Implementation plan (§ 63.787(b)) d X X Volume of coating applied at unaffected major sources (§ 63.781(b)) X Volume of each low-usage-exempt coating applied at affected sources (§ 63...

  5. 40 CFR Table 3 to Subpart II of... - Summary of Recordkeeping and Reporting Requirements abc

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... abc Requirement All Opts. Rec Rep Option 1 Rec Rep Option 2 Rec Rep Option 3 Rec Rep Notification (§ 63.9(a)-(d)) X X Implementation plan (§ 63.787(b)) d X X Volume of coating applied at unaffected major sources (§ 63.781(b)) X Volume of each low-usage-exempt coating applied at affected sources (§ 63...

  6. 40 CFR Table 3 to Subpart II of... - Summary of Recordkeeping and Reporting Requirements abc

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... abc Requirement All Opts. Rec Rep Option 1 Rec Rep Option 2 Rec Rep Option 3 Rec Rep Notification (§ 63.9(a)-(d)) X X Implementation plan (§ 63.787(b)) d X X Volume of coating applied at unaffected major sources (§ 63.781(b)) X Volume of each low-usage-exempt coating applied at affected sources (§ 63...

  7. ABC transporters affect the elimination and toxicity of CdTe quantum dots in liver and kidney cells

    SciTech Connect

    Chen, Mingli; Yin, Huancai; Bai, Pengli

    This paper aimed to investigate the role of adenosine triphosphate-binding cassette (ABC) transporters on the efflux and the toxicity of nanoparticles in liver and kidney cells. In this study, we synthesized CdTe quantum dots (QDs) that were monodispersed and emitted green fluorescence (maximum peak at 530 nm). Such QDs tended to accumulate in human hepatocellular carcinoma cells (HepG2), human kidney cells 2 (HK-2), and Madin-Darby canine kidney (MDCK) cells, and cause significant toxicity in all the three cell lines. Using specific inhibitors and inducers of P-glycoprotein (Pgp) and multidrug resistance associated proteins (Mrps), the cellular accumulation and subsequent toxicity ofmore » QDs in HepG2 and HK-2 cells were significantly affected, while only slight changes appeared in MDCK cells, corresponding well with the functional expressions of ABC transporters in cells. Moreover, treatment of QDs caused concentration- and time- dependent induction of ABC transporters in HepG2 and HK-2 cells, but such phenomenon was barely found in MDCK cells. Furthermore, the effects of CdTe QDs on ABC transporters were found to be greater than those of CdCl{sub 2} at equivalent concentrations of cadmium, indicating that the effects of QDs should be a combination of free Cd{sup 2+} and specific properties of QDs. Overall, these results indicated a strong dependence between the functional expressions of ABC transporters and the efflux of QDs, which could be an important reason for the modulation of QDs toxicity by ABC transporters. - Highlights: • ABC transporters contributed actively to the cellular efflux of CdTe quantum dots. • ABC transporters affected the cellular toxicity of CdTe quantum dots. • Treatment of CdTe quantum dots induced the gene expression of ABC transporters. • Free Cd{sup 2+} should be partially involved in the effects of QDs on ABC transporters. • Cellular efflux of quantum dots could be an important modulator for its toxicity.« less

  8. Structural basis for lipopolysaccharide extraction by ABC transporter LptB2FG.

    PubMed

    Luo, Qingshan; Yang, Xu; Yu, Shan; Shi, Huigang; Wang, Kun; Xiao, Le; Zhu, Guangyu; Sun, Chuanqi; Li, Tingting; Li, Dianfan; Zhang, Xinzheng; Zhou, Min; Huang, Yihua

    2017-05-01

    After biosynthesis, bacterial lipopolysaccharides (LPS) are transiently anchored to the outer leaflet of the inner membrane (IM). The ATP-binding cassette (ABC) transporter LptB 2 FG extracts LPS molecules from the IM and transports them to the outer membrane. Here we report the crystal structure of nucleotide-free LptB 2 FG from Pseudomonas aeruginosa. The structure reveals that lipopolysaccharide transport proteins LptF and LptG each contain a transmembrane domain (TMD), a periplasmic β-jellyroll-like domain and a coupling helix that interacts with LptB on the cytoplasmic side. The LptF and LptG TMDs form a large outward-facing V-shaped cavity in the IM. Mutational analyses suggest that LPS may enter the central cavity laterally, via the interface of the TMD domains of LptF and LptG, and is expelled into the β-jellyroll-like domains upon ATP binding and hydrolysis by LptB. These studies suggest a mechanism for LPS extraction by LptB 2 FG that is distinct from those of classical ABC transporters that transport substrates across the IM.

  9. Functional Dependence between Septal Protein SepJ from Anabaena sp. Strain PCC 7120 and an Amino Acid ABC-Type Uptake Transporter.

    PubMed

    Escudero, Leticia; Mariscal, Vicente; Flores, Enrique

    2015-08-01

    In the diazotrophic filaments of heterocyst-forming cyanobacteria, two different cell types, the CO2-fixing vegetative cells and the N2-fixing heterocysts, exchange nutrients, including some amino acids. In the model organism Anabaena sp. strain PCC 7120, the SepJ protein, composed of periplasmic and integral membrane (permease) sections, is located at the intercellular septa joining adjacent cells in the filament. The unicellular cyanobacterium Synechococcus elongatus strain PCC 7942 bears a gene, Synpcc7942_1024 (here designated dmeA), encoding a permease homologous to the SepJ permease domain. Synechococcus strains lacking dmeA or lacking dmeA and expressing Anabaena sepJ were constructed. The Synechococcus dmeA mutant showed a significant 22 to 32% decrease in the uptake of aspartate, glutamate, and glutamine, a phenotype that could be partially complemented by Anabaena sepJ. Synechococcus mutants of an ATP-binding-cassette (ABC)-type transporter for polar amino acids showed >98% decreased uptake of glutamate irrespective of the presence of dmeA or Anabaena sepJ in the same strain. Thus, Synechococcus DmeA or Anabaena SepJ is needed to observe full (or close to full) activity of the ABC transporter. An Anabaena sepJ deletion mutant was significantly impaired in glutamate and aspartate uptake, which also in this cyanobacterium requires the activity of an ABC-type transporter for polar amino acids. SepJ appears therefore to generally stimulate the activity of cyanobacterial ABC-type transporters for polar amino acids. Conversely, an Anabaena mutant of three ABC-type transporters for amino acids was impaired in the intercellular transfer of 5-carboxyfluorescein, a SepJ-related property. Our results unravel possible functional interactions in transport elements important for diazotrophic growth. Membrane transporters are essential for many aspects of cellular life, from uptake and export of substances in unicellular organisms to intercellular molecular exchange in

  10. Describing the role of Drosophila melanogaster ABC transporters in insecticide biology using CRISPR-Cas9 knockouts.

    PubMed

    Denecke, Shane; Fusetto, Roberto; Batterham, Philip

    2017-12-01

    ABC transporters have a well-established role in drug resistance, effluxing xenobiotics from cells and tissues within the organism. More recently, research has been dedicated to understanding the role insect ABC transporters play in insecticide toxicity, but progress in understanding the contribution of specific transporters has been hampered by the lack of functional genetic tools. Here, we report knockouts of three Drosophila melanogaster ABC transporter genes, Mdr49, Mdr50, and Mdr65, that are homologous to the well-studied mammalian ABCB1 (P-glycoprotein). Each knockout mutant was created in the same wild type background and tested against a panel of insecticides representing different chemical classes. Mdr65 knockouts were more susceptible to all neuroactive insecticides tested, but Mdr49 and Mdr50 knockouts showed increased susceptibility or resistance depending on the insecticide used. Mdr65 was chosen for further analysis. Calculation of LC 50 values for the Mdr65 knockout allowed the substrate specificity of this transporter to be examined. No obvious distinguishing structural features were shared among MDR65 substrates. A role for Mdr65 in insecticide transport was confirmed by testing the capacity of the knockout to synergize with the ABC inhibitor verapamil and by measuring the levels of insecticide retained in the body of knockout flies. These data unambiguously establish the influence of ABC transporters on the capacity of wild type D. melanogaster to tolerate insecticide exposure and suggest that both tissue and substrate specificity underpin this capacity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Pharmacogenomics of the human ABC transporter ABCG2: from functional evaluation to drug molecular design

    NASA Astrophysics Data System (ADS)

    Ishikawa, Toshihisa; Tamura, Ai; Saito, Hikaru; Wakabayashi, Kanako; Nakagawa, Hiroshi

    2005-10-01

    In the post-genome-sequencing era, emerging genomic technologies are shifting the paradigm for drug discovery and development. Nevertheless, drug discovery and development still remain high-risk and high-stakes ventures with long and costly timelines. Indeed, the attrition of drug candidates in preclinical and development stages is a major problem in drug design. For at least 30% of the candidates, this attrition is due to poor pharmacokinetics and toxicity. Thus, pharmaceutical companies have begun to seriously re-evaluate their current strategies of drug discovery and development. In that light, we propose that a transport mechanism-based design might help to create new, pharmacokinetically advantageous drugs, and as such should be considered an important component of drug design strategy. Performing enzyme- and/or cell-based drug transporter, interaction tests may greatly facilitate drug development and allow the prediction of drug-drug interactions. We recently developed methods for high-speed functional screening and quantitative structure-activity relationship analysis to study the substrate specificity of ABC transporters and to evaluate the effect of genetic polymorphisms on their function. These methods would provide a practical tool to screen synthetic and natural compounds, and these data can be applied to the molecular design of new drugs. In this review article, we present an overview on the genetic polymorphisms of human ABC transporter ABCG2 and new camptothecin analogues that can circumvent AGCG2-associated multidrug resistance of cancer.

  12. NFκBP65 transcription factor modulates resistance to doxorubicin through ABC transporters in breast cancer.

    PubMed

    Velaei, Kobra; Samadi, Nasser; Soltani, Sina; Barazvan, Balal; Soleimani Rad, Jafar

    2017-07-01

    Shedding light on chemoresistance biology of breast cancer could contribute to enhance the clinical outcome. Intrinsic or acquired resistance to chemotherapy is a major problem in breast cancer treatment. The NFκB pathway by siRNAP65 and JSH-23 as a translocational inhibitor of NFκBP65 in the doxorubicin-resistant MCF-7 (MCF-7/Dox) and MCF-7 cells was blocked. Then, the ABC transporter expression and function were assessed by real-time qRT-PCR and flow cytometry, respectively. Induction of apoptosis was evaluated after inhibition of the NFΚB pathway as well. Our study underlined the upregulation of NFκBP65 and anti-apoptotic Bcl-2 and downregulation of pro-apoptotic Bax in the MCF-7/Dox cells compared with control MCF-7 cells. Here, we showed that interplay between nuclear factor kappa B P65 (NFkBP65) as a transcriptional regulator and ABC transporters in the MCF-7/Dox cancer cells. We found that inhibition of the elevated expression of NFκBP65 in the resistant breast cancer, whether translocational inhibition or silencing by siRNA, decreased the expression and function of MDR1 and MRP1 efflux pumps. Furthermore, the blockade of NFκBP65 promoted apoptosis via modulating Bcl-2 and BAX expression. After inhibition of the NFκBP65 signaling pathway, elevated baseline expression of survival Bcl-2 gene in the resistant breast cells significantly decreased. Suppression of the NFκB pathway has a profound dual impact on promoting the intrinsic apoptotic pathway and reducing ABC transporter function and expression, which are some of the chemoresistance features. It was speculated that the NFκB pathway directly acts on doxorubicin-induced MDR1 and MRP1 expression in MCF-7/Dox cells.

  13. GxySBA ABC Transporter of Agrobacterium tumefaciens and Its Role in Sugar Utilization and vir Gene Expression

    PubMed Central

    Zhao, Jinlei

    2014-01-01

    Monosaccharides available in the extracellular milieu of Agrobacterium tumefaciens can be transported into the cytoplasm, or via the periplasmic sugar binding protein, ChvE, play a critical role in controlling virulence gene expression. The ChvE-MmsAB ABC transporter is involved in the utilization of a wide range of monosaccharide substrates but redundant transporters are likely given the ability of a chvE-mmsAB deletion strain to grow, albeit more slowly, in the presence of particular monosaccharides. In this study, a putative ABC transporter encoded by the gxySBA operon is identified and shown to be involved in the utilization of glucose, xylose, fucose, and arabinose, which are also substrates for the ChvE-MmsAB ABC transporter. Significantly, GxySBA is also shown to be the first characterized glucosamine ABC transporter. The divergently transcribed gene gxyR encodes a repressor of the gxySBA operon, the function of which can be relieved by a subset of the transported sugars, including glucose, xylose, and glucosamine, and this substrate-induced expression can be repressed by glycerol. Furthermore, deletion of the transporter can increase the sensitivity of the virulence gene expression system to certain sugars that regulate it. Collectively, the results reveal a remarkably diverse set of substrates for the GxySBA transporter and its contribution to the repression of sugar sensitivity by the virulence-controlling system, thereby facilitating the capacity of the bacterium to distinguish between the soil and plant environments. PMID:24957625

  14. Sulfadiazine resistance in Toxoplasma gondii: no involvement of overexpression or polymorphisms in genes of therapeutic targets and ABC transporters

    PubMed Central

    Doliwa, Christelle; Escotte-Binet, Sandie; Aubert, Dominique; Sauvage, Virginie; Velard, Frédéric; Schmid, Aline; Villena, Isabelle

    2013-01-01

    Several treatment failures have been reported for the treatment of toxoplasmic encephalitis, chorioretinitis, and congenital toxoplasmosis. Recently we found three Toxoplasma gondii strains naturally resistant to sulfadiazine and we developed in vitro two sulfadiazine resistant strains, RH-RSDZ and ME-49-RSDZ, by gradual pressure. In Plasmodium, common mechanisms of drug resistance involve, among others, mutations and/or amplification within genes encoding the therapeutic targets dhps and dhfr and/or the ABC transporter genes family. To identify genotypic and/or phenotypic markers of resistance in T. gondii, we sequenced and analyzed the expression levels of therapeutic targets dhps and dhfr, three ABC genes, two Pgp, TgABC.B1 and TgABC.B2, and one MRP, TgABC.C1, on sensitive strains compared to sulfadiazine resistant strains. Neither polymorphism nor overexpression was identified. Contrary to Plasmodium, in which mutations and/or overexpression within gene targets and ABC transporters are involved in antimalarial resistance, T. gondii sulfadiazine resistance is not related to these toxoplasmic genes studied. PMID:23707894

  15. Mutations in the Arabidopsis Peroxisomal ABC Transporter COMATOSE Allow Differentiation between Multiple Functions In Planta: Insights from an Allelic Series

    PubMed Central

    Dietrich, Daniela; Schmuths, Heike; Lousa, Carine De Marcos; Baldwin, Jocelyn M.; Baldwin, Stephen A.; Baker, Alison; Holdsworth, Michael J.

    2009-01-01

    COMATOSE (CTS), the Arabidopsis homologue of human Adrenoleukodystrophy protein (ALDP), is required for import of substrates for peroxisomal β-oxidation. A new allelic series and a homology model based on the bacterial ABC transporter, Sav1866, provide novel insights into structure-function relations of ABC subfamily D proteins. In contrast to ALDP, where the majority of mutations result in protein absence from the peroxisomal membrane, all CTS mutants produced stable protein. Mutation of conserved residues in the Walker A and B motifs in CTS nucleotide-binding domain (NBD) 1 resulted in a null phenotype but had little effect in NBD2, indicating that the NBDs are functionally distinct in vivo. Two alleles containing mutations in NBD1 outside the Walker motifs (E617K and C631Y) exhibited resistance to auxin precursors 2,4-dichlorophenoxybutyric acid (2,4-DB) and indole butyric acid (IBA) but were wild type in all other tests. The homology model predicted that the transmission interfaces are domain-swapped in CTS, and the differential effects of mutations in the conserved “EAA motif” of coupling helix 2 supported this prediction, consistent with distinct roles for each NBD. Our findings demonstrate that CTS functions can be separated by mutagenesis and the structural model provides a framework for interpretation of phenotypic data. PMID:19019987

  16. Genome-Wide Identification, Characterization and Phylogenetic Analysis of ATP-Binding Cassette (ABC) Transporter Genes in Common Carp (Cyprinus carpio).

    PubMed

    Liu, Xiang; Li, Shangqi; Peng, Wenzhu; Feng, Shuaisheng; Feng, Jianxin; Mahboob, Shahid; Al-Ghanim, Khalid A; Xu, Peng

    2016-01-01

    The ATP-binding cassette (ABC) gene family is considered to be one of the largest gene families in all forms of prokaryotic and eukaryotic life. Although the ABC transporter genes have been annotated in some species, detailed information about the ABC superfamily and the evolutionary characterization of ABC genes in common carp (Cyprinus carpio) are still unclear. In this research, we identified 61 ABC transporter genes in the common carp genome. Phylogenetic analysis revealed that they could be classified into seven subfamilies, namely 11 ABCAs, six ABCBs, 19 ABCCs, eight ABCDs, two ABCEs, four ABCFs, and 11 ABCGs. Comparative analysis of the ABC genes in seven vertebrate species including common carp, showed that at least 10 common carp genes were retained from the third round of whole genome duplication, while 12 duplicated ABC genes may have come from the fourth round of whole genome duplication. Gene losses were also observed for 14 ABC genes. Expression profiles of the 61 ABC genes in six common carp tissues (brain, heart, spleen, kidney, intestine, and gill) revealed extensive functional divergence among the ABC genes. Different copies of some genes had tissue-specific expression patterns, which may indicate some gene function specialization. This study provides essential genomic resources for future studies in common carp.

  17. Genome-Wide Identification, Characterization and Phylogenetic Analysis of ATP-Binding Cassette (ABC) Transporter Genes in Common Carp (Cyprinus carpio)

    PubMed Central

    Peng, Wenzhu; Feng, Shuaisheng; Feng, Jianxin; Mahboob, Shahid; Al-Ghanim, Khalid A.

    2016-01-01

    The ATP-binding cassette (ABC) gene family is considered to be one of the largest gene families in all forms of prokaryotic and eukaryotic life. Although the ABC transporter genes have been annotated in some species, detailed information about the ABC superfamily and the evolutionary characterization of ABC genes in common carp (Cyprinus carpio) are still unclear. In this research, we identified 61 ABC transporter genes in the common carp genome. Phylogenetic analysis revealed that they could be classified into seven subfamilies, namely 11 ABCAs, six ABCBs, 19 ABCCs, eight ABCDs, two ABCEs, four ABCFs, and 11 ABCGs. Comparative analysis of the ABC genes in seven vertebrate species including common carp, showed that at least 10 common carp genes were retained from the third round of whole genome duplication, while 12 duplicated ABC genes may have come from the fourth round of whole genome duplication. Gene losses were also observed for 14 ABC genes. Expression profiles of the 61 ABC genes in six common carp tissues (brain, heart, spleen, kidney, intestine, and gill) revealed extensive functional divergence among the ABC genes. Different copies of some genes had tissue-specific expression patterns, which may indicate some gene function specialization. This study provides essential genomic resources for future studies in common carp. PMID:27058731

  18. Emission of volatile organic compounds from petunia flowers is facilitated by an ABC transporter.

    PubMed

    Adebesin, Funmilayo; Widhalm, Joshua R; Boachon, Benoît; Lefèvre, François; Pierman, Baptiste; Lynch, Joseph H; Alam, Iftekhar; Junqueira, Bruna; Benke, Ryan; Ray, Shaunak; Porter, Justin A; Yanagisawa, Makoto; Wetzstein, Hazel Y; Morgan, John A; Boutry, Marc; Schuurink, Robert C; Dudareva, Natalia

    2017-06-30

    Plants synthesize a diversity of volatile molecules that are important for reproduction and defense, serve as practical products for humans, and influence atmospheric chemistry and climate. Despite progress in deciphering plant volatile biosynthesis, their release from the cell has been poorly understood. The default assumption has been that volatiles passively diffuse out of cells. By characterization of a Petunia hybrida adenosine triphosphate-binding cassette (ABC) transporter, PhABCG1, we demonstrate that passage of volatiles across the plasma membrane relies on active transport. PhABCG1 down-regulation by RNA interference results in decreased emission of volatiles, which accumulate to toxic levels in the plasma membrane. This study provides direct proof of a biologically mediated mechanism of volatile emission. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  19. NtPDR3, an iron-deficiency inducible ABC transporter in Nicotiana tabacum.

    PubMed

    Ducos, Eric; Fraysse, Staffan; Boutry, Marc

    2005-12-19

    In plants, the ABC transporter PDR (pleiotropic drug resistance) subfamily is composed of approximately 15 genes, few of which have been analyzed. We have identified NtPDR3, a Nicotiana tabacum PDR gene belonging to a cluster for which no functional data was previously available. NtPDR3 was found to be induced in suspension cells treated with methyl jasmonate, salicylic acid, 1-naphthalene acetic acid, or cembrene, a macrocyclic diterpene. In agreement with the identification of a putative iron deficiency element in the NtPDR3 transcription promoter region, we found that iron deficiency in the culture medium induced NtPDR3 expression, thus suggesting a new function of the PDR transporter family.

  20. A new ABC half-transporter in Leishmania major is involved in resistance to antimony.

    PubMed

    Manzano, J I; García-Hernández, R; Castanys, S; Gamarro, F

    2013-08-01

    The characterization of ABCI4, a new intracellular ATP-binding cassette (ABC) half-transporter in Leishmania major, is described. We show that ABCI4 is involved in heavy metal export, thereby conferring resistance to Pentostam, to Sb(III), and to As(III) and Cd(II). Parasites overexpressing ABCI4 showed a lower mitochondrial toxic effect of antimony by decreasing reactive oxygen species production and maintained higher values of both the mitochondrial electrochemical potential and total ATP levels with respect to controls. The ABCI4 half-transporter forms homodimers as determined by a coimmunoprecipitation assay. A combination of subcellular localization studies under a confocal microscope and a surface biotinylation assay using parasites expressing green fluorescent protein- and FLAG-tagged ABCI4 suggests that the transporter presents a dual localization in both mitochondria and the plasma membrane. Parasites overexpressing ABCI4 present an increased replication in mouse peritoneal macrophages. We have determined that porphyrins are substrates for ABCI4. Consequently, the overexpression of ABCI4 confers resistance to some toxic porphyrins, such as zinc-protoporphyrin, due to the lower accumulation resulting from a significant efflux, as determined using the fluorescent zinc-mesoporphyrin, a validated heme analog. In addition, ABCI4 has a significant ability to efflux thiol after Sb(III) incubation, thus meaning that ABCI4 could be considered to be a potential thiol-X-pump that is able to recognize metal-conjugated thiols. In summary, we have shown that this new ABC transporter is involved in drug sensitivity to antimony and other compounds by efflux as conjugated thiol complexes.

  1. Identification of Residues in the Lipopolysaccharide ABC Transporter That Coordinate ATPase Activity with Extractor Function.

    PubMed

    Simpson, Brent W; Owens, Tristan W; Orabella, Matthew J; Davis, Rebecca M; May, Janine M; Trauger, Sunia A; Kahne, Daniel; Ruiz, Natividad

    2016-10-18

    The surface of most Gram-negative bacteria is covered with lipopolysaccharide (LPS), creating a permeability barrier against toxic molecules, including many antimicrobials. To assemble LPS on their surface, Gram-negative bacteria must extract newly synthesized LPS from the inner membrane, transport it across the aqueous periplasm, and translocate it across the outer membrane. The LptA to -G proteins assemble into a transenvelope complex that transports LPS from the inner membrane to the cell surface. The Lpt system powers LPS transport from the inner membrane by using a poorly characterized ATP-binding cassette system composed of the ATPase LptB and the transmembrane domains LptFG. Here, we characterize a cluster of residues in the groove region of LptB that is important for controlling LPS transport. We also provide the first functional characterization of LptFG and identify their coupling helices that interact with the LptB groove. Substitutions at conserved residues in these coupling helices compromise both the assembly and function of the LptB 2 FG complex. Defects in LPS transport conferred by alterations in the LptFG coupling helices can be rescued by changing a residue in LptB that is adjacent to functionally important residues in the groove region. This suppression is achieved by increasing the ATPase activity of the LptB 2 FG complex. Taken together, these data identify a specific binding site in LptB for the coupling helices of LptFG that is responsible for coupling of ATP hydrolysis by LptB with LptFG function to achieve LPS extraction. Lipopolysaccharide (LPS) is synthesized at the cytoplasmic membrane of Gram-negative bacteria and transported across several compartments to the cell surface, where it forms a barrier that protects these organisms from antibiotics. The LptB 2 FG proteins form an ATP-binding cassette (ABC) transporter that uses energy from ATP hydrolysis in the cytoplasm to facilitate extraction of LPS from the outer face of the

  2. ABC multidrug transporters: target for modulation of drug pharmacokinetics and drug-drug interactions.

    PubMed

    Marquez, Béatrice; Van Bambeke, Françoise

    2011-05-01

    Nine proteins of the ABC superfamily (P-glycoprotein, 7 MRPs and BCRP) are involved in multidrug transport. Being localised at the surface of endothelial or epithelial cells, they expel drugs back to the external medium (if located at the apical side [P-glycoprotein, BCRP, MRP2, MRP4 in the kidney]) or to the blood (if located at the basolateral side [MRP1, MRP3, MRP4, MRP5]), modulating thereby their absorption, distribution, and elimination. In the CNS, most transporters are oriented to expel drugs to the blood. Transporters also cooperate with Phase I/Phase II metabolism enzymes by eliminating drug metabolites. Their major features are (i) their capacity to recognize drugs belonging to unrelated pharmacological classes, and (ii) their redundancy, a single molecule being possibly substrate for different transporters. This ensures an efficient protection of the body against invasion by xenobiotics. Competition for transport is now characterized as a mechanism of interaction between co-administered drugs, one molecule limiting the transport of the other, potentially affecting bioavailability, distribution, and/or elimination. Again, this mechanism reinforces drug interactions mediated by cytochrome P450 inhibition, as many substrates of P-glycoprotein and CYP3A4 are common. Induction of the expression of genes coding for MDR transporters is another mechanism of drug interaction, which could affect all drug substrates of the up-regulated transporter. Overexpression of MDR transporters confers resistance to anticancer agents and other therapies. All together, these data justify why studying drug active transport should be part of the evaluation of new drugs, as recently recommended by the FDA.

  3. Barley has two peroxisomal ABC transporters with multiple functions in β-oxidation

    PubMed Central

    Mendiondo, Guillermina M.; Medhurst, Anne; van Roermund, Carlo W.; Zhang, Xuebin; Devonshire, Jean; Scholefield, Duncan; Fernández, José; Axcell, Barry; Ramsay, Luke; Waterham, Hans R.; Waugh, Robbie; Theodoulou, Frederica L.; Holdsworth, Michael J.

    2014-01-01

    In oilseed plants, peroxisomal β-oxidation functions not only in lipid catabolism but also in jasmonate biosynthesis and metabolism of pro-auxins. Subfamily D ATP-binding cassette (ABC) transporters mediate import of β-oxidation substrates into the peroxisome, and the Arabidopsis ABCD protein, COMATOSE (CTS), is essential for this function. Here, the roles of peroxisomal ABCD transporters were investigated in barley, where the main storage compound is starch. Barley has two CTS homologues, designated HvABCD1 and HvABCD2, which are widely expressed and present in embryo and aleurone tissues during germination. Suppression of both genes in barley RNA interference (RNAi) lines indicated roles in metabolism of 2,4-dichlorophenoxybutyrate (2,4-DB) and indole butyric acid (IBA), jasmonate biosynthesis, and determination of grain size. Transformation of the Arabidopsis cts-1 null mutant with HvABCD1 and HvABCD2 confirmed these findings. HvABCD2 partially or completely complemented all tested phenotypes of cts-1. In contrast, HvABCD1 failed to complement the germination and establishment phenotypes of cts-1 but increased the sensitivity of hypocotyls to 100 μM IBA and partially complemented the seed size phenotype. HvABCD1 also partially complemented the yeast pxa1/pxa2Δ mutant for fatty acid β-oxidation. It is concluded that the core biochemical functions of peroxisomal ABC transporters are largely conserved between oilseeds and cereals but that their physiological roles and importance may differ. PMID:24913629

  4. Investigation of the quaternary structure of an ABC transporter in living cells using spectrally resolved resonance energy transfer

    NASA Astrophysics Data System (ADS)

    Singh, Deo Raj

    Forster resonance energy transfer (FRET) has become an important tool to study proteins inside living cells. It has been used to explore membrane protein folding and dynamics, determine stoichiometry and geometry of protein complexes, and measure the distance between two molecules. In this dissertation, we use a method based on FRET and optical micro-spectroscopy (OptiMiS) technology, developed in our lab, to probe the structure of dynamic (as opposed to static) protein complexes in living cells. We use this method to determine the association stoichiometry and quaternary structure of an ABC transporter in living cells. Specifically, the transporter we investigate originates from the pathogen Pseudomonas aeruginosa, which is a Gram-negative bacterium with several virulence factors, lipopolysaccharides being one of them. This pathogen coexpresses two unique forms of lipopolysaccharides on its surface, the A- and B-bands. The A-band polysaccharides, synthesized in the cytoplasm, are translocated into the periplasm through an ATP-binding-cassette (ABC) transporter consisting of a transmembranar protein, Wzm, and a nucleotide-binding protein, Wzt. In P. aeruginosa, all of the biochemical studies of A-band LPS are concentrated on the stages of the synthesis and ligation of polysaccharides (PSs), leaving the export stage involving ABC transporter unexplored. The mode of PS export through ABC transporters is still unknown. This difficulty is due to the lack of information about sub-unit composition and structure of this bi-component ABC transporter. Using the FRET-OptiMiS combination method developed by our lab, we found that Wzt forms a rhombus-shaped homo-tetramer which becomes a square upon co-expression with Wzm, and that Wzm forms a square-shaped homo-tetramer both in the presence and absence of Wzt. Based on these results, we propose a structural model for the double-tetramer complex formed by the bi-component ABC transporter in living cells. An understanding of the

  5. Trichothecene resistance in wheat: Development of molecular markers for PDR-type ABC transporter genes.

    PubMed

    Mitterbauer, R; Heinrich, M; Rauscher, R; Lemmens, M; Bürstmayr, H; Adam, G

    2003-03-01

    Infection withFusarium graminearum andF. culmorum not only causes severe yield and quality losses, the most relevant concern is the contamination of cereal foods and feeds with trichothecenes (e.g. deoxynivalenol, DON). The ability to synthesize trichothecenes has been shown to be a virulence factor ofF. graminearum on wheat and, on the other hand, toxin resistance is most likely an important component of field resistance. Our hypothesis is that pleiotropic drug resistance mediated by PDR-type ABC transporter proteins (acting as membrane located drug efflux pumps) is a relevant mechanism of DON resistance not only in yeast but also in wheat. Goal of this project is the development of molecular markers for this gene family for use in marker-assisted plant breeding programs. The technical difficulties caused by the large size of the PDR-family are discussed.

  6. Human and Rat ABC Transporter Efflux of Bisphenol A and Bisphenol A Glucuronide: Interspecies Comparison and Implications for Pharmacokinetic Assessment

    EPA Science Inventory

    Significant interspecies differences exist between human and rodent with respect to absorption, distribution, and excretion of bisphenol A (BPA) and its primary metabolite, BPA-glucuronide (BPA-G). ATP-Binding Cassette (ABC) transporter enzymes play important roles in these physi...

  7. Inhibition of the Human ABC Efflux Transporters P-gp and ...

    EPA Pesticide Factsheets

    High body burdens of polybrominated diphenyl ethers (PBDEs) in infants and young children have led to increased concern over their potential impact on human development. PBDE exposure can alter the expression of genes involved in thyroid homeostasis, including those of ATP-binding cassette (ABC) transporters, which mediate cellular xenobiotic efflux. However, little information exists on how PBDEs interact with ABC transporters such as P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP). The purpose of this study was to evaluate the interactions of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) and its hydroxylated metabolite 6-OH-BDE-47 with P-gp and BCRP, using human MDR1- and BCRP-expressing membrane vesicles and stably transfected NIH-3T3-MDR1 and MDCK-BCRP cells. In P-gp membranes, BDE-47 did not affect P-gp activity; however, 6-OH-BDE-47 inhibited P-gp activity at low µM concentrations (IC50 = 11.7 µM). In BCRP membranes, BDE-47 inhibited BCRP activity; however, 6-OH-BDE-47 was a stronger inhibitor [IC50 = 45.9 µM (BDE-47) vs. IC50 = 9.4 µM (6-OH-BDE-47)]. Intracellular concentrations of known P-gp and BCRP substrates [(3H)-paclitaxel and (3H)-prazosin, respectively] were significantly higher (indicating less efflux) in NIH-3T3-MDR1 and MDCK-BCRP cells in the presence of 6-OH-BDE-47, but not BDE-47. Collectively, our results indicate that the BDE-47 metabolite 6-OH-BDE-47 is an inhibitor of both P-gp and BCRP efflux activity.

  8. ATP-binding cassette (ABC) transporters in caprine preantral follicles: gene and protein expression.

    PubMed

    Guerreiro, Denise Damasceno; de Lima, Laritza Ferreira; Mbemya, Gildas Tetaping; Maside, Carolina Mielgo; Miranda, André Marrocos; Tavares, Kaio César Simiano; Alves, Benner Geraldo; Faustino, Luciana Rocha; Smitz, Johan; de Figueiredo, José Ricardo; Rodrigues, Ana Paula Ribeiro

    2018-06-01

    The multidrug resistance proteins ABCB1, ABCC2 and ABCG2 are an energy-dependent efflux pump that functions in systemic detoxification processes. Physiologically expressed in a variety of tissues, most abundantly in the liver and intestinal epithelia, placenta, blood-brain barrier and various stem cells, until now, these pumps were not identified in goat ovarian tissue. Therefore, the aim of this study is to analyze ABCB1, ABCC2, and ABCG2 mRNA and protein expression in goat preantral follicles. Fragments (3 × 3 × 1 mm) from five pairs of ovary (n = 10) obtained from five goat were collected and immediately submitted to qPCR, Western blot, and immunofluorescence assay for mRNA detection and identification and localization of the ABC transporters, respectively. mRNA for ABCB1, ABCC2, and ABCG2 and the presence of their proteins were observed on ovarian tissue samples. Positive marks were observed for the three transport proteins in all follicular categories studied. However, the marks were primarily localized in the oocyte of primordial, transition and primary follicle categories. In conclusion, goat ovarian tissue expresses mRNA for the ABCB1, ABCC2 and ABCG2 transporters and the expression of these proteins in the preantral follicles is a follicle-dependent stage.

  9. The ABC transporter Rv1272c of Mycobacterium tuberculosis enhances the import of long-chain fatty acids in Escherichia coli.

    PubMed

    Martin, Audrey; Daniel, Jaiyanth

    2018-02-05

    Mycobacterium tuberculosis (Mtb), which causes tuberculosis, is capable of accumulating triacylglycerol (TAG) by utilizing fatty acids from host cells. ATP-binding cassette (ABC) transporters are involved in transport processes in all organisms. Among the classical ABC transporters in Mtb none have been implicated in fatty acid import. Since the transport of fatty acids from the host cell is important for dormancy-associated TAG synthesis in the pathogen, mycobacterial ABC transporter(s) could potentially be involved in this process. Based on sequence identities with a bacterial ABC transporter that mediates fatty acid import for TAG synthesis, we identified Rv1272c, a hitherto uncharacterized ABC-transporter in Mtb that also shows sequence identities with a plant ABC transporter involved in fatty acid transport. We expressed Rv1272c in E. coli and show that it enhances the import of radiolabeled fatty acids. We also show that Rv1272c causes a significant increase in the metabolic incorporation of radiolabeled long-chain fatty acids into cardiolipin, a tetra-acylated phospholipid, and phosphatidylglycerol in E. coli. This is the first report on the function of Rv1272c showing that it displays a long-chain fatty acid transport function. Copyright © 2018 Elsevier Inc. All rights reserved.

  10. Characterization of acquired paclitaxel resistance of breast cancer cells and involvement of ABC transporters

    SciTech Connect

    Němcová-Fürstová, Vlasta, E-mail: vlasta.furstova@

    Development of taxane resistance has become clinically very important issue. The molecular mechanisms underlying the resistance are still unclear. To address this issue, we established paclitaxel-resistant sublines of the SK-BR-3 and MCF-7 breast cancer cell lines that are capable of long-term proliferation in 100 nM and 300 nM paclitaxel, respectively. Application of these concentrations leads to cell death in the original counterpart cells. Both sublines are cross-resistant to doxorubicin, indicating the presence of the MDR phenotype. Interestingly, resistance in both paclitaxel-resistant sublines is circumvented by the second-generation taxane SB-T-1216. Moreover, we demonstrated that it was not possible to establish sublinesmore » of SK-BR-3 and MCF-7 cells resistant to this taxane. It means that at least the tested breast cancer cells are unable to develop resistance to some taxanes. Employing mRNA expression profiling of all known human ABC transporters and subsequent Western blot analysis of the expression of selected transporters, we demonstrated that only the ABCB1/PgP and ABCC3/MRP3 proteins were up-regulated in both paclitaxel-resistant sublines. We found up-regulation of ABCG2/BCRP and ABCC4 proteins only in paclitaxel-resistant SK-BR-3 cells. In paclitaxel-resistant MCF-7 cells, ABCB4/MDR3 and ABCC2/MRP2 proteins were up-regulated. Silencing of ABCB1 expression using specific siRNA increased significantly, but did not completely restore full sensitivity to both paclitaxel and doxorubicin. Thus we showed a key, but not exclusive, role for ABCB1 in mechanisms of paclitaxel resistance. It suggests the involvement of multiple mechanisms in paclitaxel resistance in tested breast cancer cells. - Highlights: • Expression of all ABC transporters in paclitaxel-resistant sublines of SK-BR-3 and MCF-7 cells was analyzed. • SK-BR-3 and MCF-7 cells are unable to develop resistance to some taxanes. • Some taxanes are able to overcome developed resistance to

  11. Overexpression of the ABC transporter AvtAB increases avermectin production in Streptomyces avermitilis.

    PubMed

    Qiu, Jingfan; Zhuo, Ying; Zhu, Dongqing; Zhou, Xiufen; Zhang, Lixin; Bai, Linquan; Deng, Zixin

    2011-10-01

    Avermectins are 16-membered macrocyclic polyketides with potent antiparasitic activities, produced by Streptomyces avermitilis. Upstream of the avermectin biosynthetic gene cluster, there is the avtAB operon encoding the ABC transporter AvtAB, which is highly homologous to the mammalian multidrug efflux pump P-glycoprotein (Pgp). Inactivation of avtAB had no effect, but increasing the concentration of avtAB mRNA 30-500-fold, using a multi-copy plasmid in S. avermitilis, enhanced avermectin production about two-fold both in the wild-type and in a high-yield producer strain on agar plates. In liquid industrial fermentation medium, the overall productivity of avermectin B1a in the engineered high-yield producer was improved for about 50%, from 3.3 to 4.8 g/l. In liquid YMG medium, moreover, the ratio of intracellular to extracellular accumulation of avermectin B1a was dropped from 6:1 to 4.5:1 in response to multiple copies of avtAB. Additionally, the overexpression of avtAB did not cause any increased expression of the avermectin biosynthetic genes through RT-PCR analysis. We propose that the AvtAB transporter exports avermectin, and thus reduces the feedback inhibition on avermectin production inside the cell. This strategy may be useful for enhancing the production of other antibiotics.

  12. The structure of the human ABC transporter ABCG2 reveals a novel mechanism for drug extrusion.

    PubMed

    Khunweeraphong, Narakorn; Stockner, Thomas; Kuchler, Karl

    2017-10-23

    The human ABC transporter ABCG2 (Breast Cancer Resistance Protein, BCRP) is implicated in anticancer resistance, in detoxification across barriers and linked to gout. Here, we generate a novel atomic model of ABCG2 using the crystal structure of ABCG5/G8. Extensive mutagenesis verifies the structure, disclosing hitherto unrecognized essential residues and domains in the homodimeric ABCG2 transporter. The elbow helix, the first intracellular loop (ICL1) and the nucleotide-binding domain (NBD) constitute pivotal elements of the architecture building the transmission interface that borders a central cavity which acts as a drug trap. The transmission interface is stabilized by salt-bridge interactions between the elbow helix and ICL1, as well as within ICL1, which is essential to control the conformational switch of ABCG2 to the outward-open drug-releasing conformation. Importantly, we propose that ICL1 operates like a molecular spring that holds the NBD dimer close to the membrane, thereby enabling efficient coupling of ATP hydrolysis during the catalytic cycle. These novel mechanistic data open new opportunities to therapeutically target ABCG2 in the context of related diseases.

  13. The yeast plasma membrane ATP binding cassette (ABC) transporter Aus1: purification, characterization, and the effect of lipids on its activity.

    PubMed

    Marek, Magdalena; Milles, Sigrid; Schreiber, Gabriele; Daleke, David L; Dittmar, Gunnar; Herrmann, Andreas; Müller, Peter; Pomorski, Thomas Günther

    2011-06-17

    The ATP binding cassette (ABC) transporter Aus1 is expressed under anaerobic growth conditions at the plasma membrane of the yeast Saccharomyces cerevisiae and is required for sterol uptake. These observations suggest that Aus1 promotes the translocation of sterols across membranes, but the precise transport mechanism has yet to be identified. In this study, an extraction and purification procedure was developed to characterize the Aus1 transporter. The detergent-solubilized protein was able to bind and hydrolyze ATP. Mutagenesis of the conserved lysine to methionine in the Walker A motif abolished ATP hydrolysis. Likewise, ATP hydrolysis was inhibited by classical inhibitors of ABC transporters. Upon reconstitution into proteoliposomes, the ATPase activity of Aus1 was specifically stimulated by phosphatidylserine (PS) in a stereoselective manner. We also found that Aus1-dependent sterol uptake, but not Aus1 expression and trafficking to the plasma membrane, was affected by changes in cellular PS levels. These results suggest a direct interaction between Aus1 and PS that is critical for the activity of the transporter.

  14. Multiple ABC glucoside transporters mediate sugar-stimulated growth in the heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120.

    PubMed

    Nieves-Morión, Mercedes; Flores, Enrique

    2018-02-01

    Cyanobacteria are generally capable of photoautotrophic growth and are widely distributed on Earth. The model filamentous, heterocyst-forming strain Anabaena sp. PCC 7120 has long been considered as a strict photoautotroph but is now known to be able to assimilate fructose. We have previously described two components of ABC glucoside uptake transporters from Anabaena that are involved in uptake of the sucrose analog esculin: GlsC [a nucleotide-binding domain subunit (NBD)] and GlsP [a transmembrane component (TMD)]. Here, we created Anabaena mutants of genes encoding three further ABC transporter components needed for esculin uptake: GlsD (NBD), GlsQ (TMD) and GlsR (periplasmic substrate-binding protein). Phototrophic growth of Anabaena was significantly stimulated by sucrose, fructose and glucose. Whereas the glsC and glsD mutants were drastically hampered in sucrose-stimulated growth, the different gls mutants were generally impaired in sugar-dependent growth. Our results suggest the participation of Gls and other ABC transporters encoded in the Anabaena genome in sugar-stimulated growth. Additionally, Gls transporter components influence the function of septal junctions in the Anabaena filament. We suggest that mixotrophic growth is important in cyanobacterial physiology and may be relevant for the wide success of these organisms in diverse environments. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  15. Drug resistance-associated changes in sphingolipids and ABC transporters occur in different regions of membrane domains.

    PubMed

    Hinrichs, John W J; Klappe, Karin; van Riezen, Manon; Kok, Jan W

    2005-11-01

    We have recently shown that two ATP binding cassette (ABC) transporters are enriched in Lubrol-resistant noncaveolar membrane domains in multidrug-resistant human cancer cells [Hinrichs, J. W. J., K. Klappe, I. Hummel, and J. W. Kok. 2004. ATP-binding cassette transporters are enriched in non-caveolar detergent-insoluble glycosphingolipid-enriched membrane domains (DIGs) in human multidrug-resistant cancer cells. J. Biol. Chem. 279: 5734-5738]. Here, we show that aminophospholipids are relatively enriched in Lubrol-resistant membrane domains compared with Triton X-100-resistant membrane domains, whereas sphingolipids are relatively enriched in the latter. Moreover, Lubrol-resistant membrane domains contain more protein and lipid mass. Based on these results, we postulate a model for detergent-insoluble glycosphingolipid-enriched membrane domains consisting of a Lubrol-insoluble/Triton X-100-insoluble region and a Lubrol-insoluble/Triton X-100-soluble region. The latter region contains most of the ABC transporters as well as lipids known to be necessary for their efflux activity. Compared with drug-sensitive cells, the detergent-insoluble glycosphingolipid-enriched membrane domains (DIGs) in drug-resistant cells differ specifically in sphingolipid content and not in protein, phospholipid, or cholesterol content. In drug-resistant cells, sphingolipids with specific fatty acids (especially C24:1) are enriched in these membrane domains. Together, these data show that multidrug resistance-associated changes in both sphingolipids and ABC transporters occur in DIGs, but in different regions of these domains.

  16. Functional assignment of solute-binding proteins of ABC transporters using a fluorescence-based thermal shift assay.

    SciTech Connect

    Giulliani, S. E.; Frank, A. E.; Collart, F. R.

    2008-12-08

    We have used a fluorescence-based thermal shift (FTS) assay to identify amino acids that bind to solute-binding proteins in the bacterial ABC transporter family. The assay was validated with a set of six proteins with known binding specificity and was consistently able to map proteins with their known binding ligands. The assay also identified additional candidate binding ligands for several of the amino acid-binding proteins in the validation set. We extended this approach to additional targets and demonstrated the ability of the FTS assay to unambiguously identify preferential binding for several homologues of amino acid-binding proteins with known specificity andmore » to functionally annotate proteins of unknown binding specificity. The assay is implemented in a microwell plate format and provides a rapid approach to validate an anticipated function or to screen proteins of unknown function. The ABC-type transporter family is ubiquitous and transports a variety of biological compounds, but the current annotation of the ligand-binding proteins is limited to mostly generic descriptions of function. The results illustrate the feasibility of the FTS assay to improve the functional annotation of binding proteins associated with ABC-type transporters and suggest this approach that can also be extended to other protein families.« less

  17. ABC transporter content diversity in Streptococcus pneumoniae impacts competence regulation and bacteriocin production.

    PubMed

    Wang, Charles Y; Patel, Nisha; Wholey, Wei-Yun; Dawid, Suzanne

    2018-06-19

    The opportunistic pathogen Streptococcus pneumoniae (pneumococcus) uses natural genetic competence to increase its adaptability through horizontal gene transfer. One method of acquiring DNA is through predation of neighboring strains with antimicrobial peptides called "bacteriocins." Competence and production of the major family of pneumococcal bacteriocins, pneumocins, are regulated by the quorum-sensing systems com and blp , respectively. In the classical paradigm, the ABC transporters ComAB and BlpAB each secretes its own system's signaling pheromone and in the case of BlpAB also secretes the pneumocins. While ComAB is found in all pneumococci, only 25% of strains encode an intact version of BlpAB [BlpAB(+)] while the rest do not [BlpAB(-)]. Contrary to the classical paradigm, it was previously shown that BlpAB(-) strains can activate blp through ComAB-mediated secretion of the blp pheromone during brief periods of competence. To better understand the full extent of com - blp crosstalk, we examined the contribution of each transporter to competence development and pneumocin secretion. We found that BlpAB(+) strains have a greater capacity for competence activation through BlpAB-mediated secretion of the com pheromone. Similarly, we show that ComAB and BlpAB are promiscuous and both can secrete pneumocins. Consequently, differences in pneumocin secretion between BlpAB(+) and BlpAB(-) strains derive from the regulation and kinetics of transporter expression rather than substrate specificity. We speculate that BlpAB(-) strains (opportunists) use pneumocins mainly in a narrowly tailored role for DNA acquisition and defense during competence while BlpAB(+) strains (aggressors) expand their use for the general inhibition of rival strains. Copyright © 2018 the Author(s). Published by PNAS.

  18. Maltose Uptake by the Novel ABC Transport System MusEFGK2I Causes Increased Expression of ptsG in Corynebacterium glutamicum

    PubMed Central

    Henrich, Alexander; Kuhlmann, Nora; Eck, Alexander W.; Krämer, Reinhard

    2013-01-01

    The Gram-positive Corynebacterium glutamicum efficiently metabolizes maltose by a pathway involving maltodextrin and glucose formation by 4-α-glucanotransferase, glucose phosphorylation by glucose kinases, and maltodextrin degradation via maltodextrin phosphorylase and α-phosphoglucomutase. However, maltose uptake in C. glutamicum has not been investigated. Interestingly, the presence of maltose in the medium causes increased expression of ptsG in C. glutamicum by an unknown mechanism, although the ptsG-encoded glucose-specific EII permease of the phosphotransferase system itself is not required for maltose utilization. We identified the maltose uptake system as an ABC transporter encoded by musK (cg2708; ATPase subunit), musE (cg2705; substrate binding protein), musF (cg2704; permease), and musG (cg2703; permease) by combination of data obtained from characterization of maltose uptake and reanalyses of transcriptome data. Deletion of the mus gene cluster in C. glutamicum Δmus abolished maltose uptake and utilization. Northern blotting and reverse transcription-PCR experiments revealed that musK and musE are transcribed monocistronically, whereas musF and musG are part of an operon together with cg2701 (musI), which encodes a membrane protein of unknown function with no homologies to characterized proteins. Characterization of growth and [14C]maltose uptake in the musI insertion strain C. glutamicum IMcg2701 showed that musI encodes a novel essential component of the maltose ABC transporter of C. glutamicum. Finally, ptsG expression during cultivation on different carbon sources was analyzed in the maltose uptake-deficient strain C. glutamicum Δmus. Indeed, maltose uptake by the novel ABC transport system MusEFGK2I is required for the positive effect of maltose on ptsG expression in C. glutamicum. PMID:23543710

  19. Minireview: SLCO and ABC Transporters: A Role for Steroid Transport in Prostate Cancer Progression

    PubMed Central

    Cho, Eunpi; Montgomery, R. Bruce

    2014-01-01

    Androgens play a critical role in the development and progression of prostate cancer (PCa), and androgen deprivation therapy via surgical or medical castration is front-line therapy for patients with advanced PCa. However, intratumoral testosterone levels are elevated in metastases from patients with castration-resistant disease, and residual intratumoral androgens have been implicated in mediating ligand-dependent mechanisms of androgen receptor activation. The source of residual tissue androgens present despite castration has not been fully elucidated, but proposed mechanisms include uptake and conversion of adrenal androgens, such as dehdroepiandrosterone to testosterone and dihydrotestosterone, or de novo androgen synthesis from cholesterol or progesterone precursors. In this minireview, we discuss the emerging evidence that suggests a role for specific transporters in mediating transport of steroids into or out of prostate cells, thereby influencing intratumoral androgen levels and PCa development and progression. We focus on the solute carrier and ATP binding cassette gene families, which have the most published data for a role in PCa-related steroid transport, and review the potential impact of genetic variation on steroid transport activity and PCa outcomes. Continued assessment of transport activity in PCa models and human tumor tissue is needed to better delineate the different roles these transporters play in physiologic and neoplastic settings, and in order to determine whether targeting the uptake of steroid substrates by specific transporters may be a clinically feasible therapeutic strategy. PMID:25147980

  20. Osmoregulated ABC-transport system of Lactococcus lactis senses water stress via changes in the physical state of the membrane.

    PubMed

    van der Heide, T; Poolman, B

    2000-06-20

    An osmoregulated ABC transporter (OpuA) with novel structural features has been identified that responds to water stress. This glycine betaine transport system consists of an ATP-binding/hydrolyzing subunit (OpuAA) and a protein (OpuABC) that contains both the translocator and the substrate-binding domain. The components of OpuA have been overexpressed, purified, and functionally incorporated into liposomes with an ATP-regenerating system in the vesicle lumen. A transmembrane osmotic gradient (outside hyperosmotic relative to the inside) of both ionic and nonionic compounds was able to osmotically activate OpuA in the proteoliposomal system. Hypoosmotic medium conditions inhibited the basal activity of the system. The data show that OpuAA and OpuABC are sufficient for osmoregulated transport, indicating that OpuA can act both as osmosensor and osmoregulator. Strikingly, OpuA could also be activated by low concentrations of cationic and anionic amphipaths, which interact with the membrane. This result indicates that activation by a transmembrane osmotic gradient is mediated by changes in membrane properties/protein-lipid interactions.

  1. Osmoregulated ABC-transport system of Lactococcus lactis senses water stress via changes in the physical state of the membrane

    PubMed Central

    van der Heide, Tiemen; Poolman, Bert

    2000-01-01

    An osmoregulated ABC transporter (OpuA) with novel structural features has been identified that responds to water stress. This glycine betaine transport system consists of an ATP-binding/hydrolyzing subunit (OpuAA) and a protein (OpuABC) that contains both the translocator and the substrate-binding domain. The components of OpuA have been overexpressed, purified, and functionally incorporated into liposomes with an ATP-regenerating system in the vesicle lumen. A transmembrane osmotic gradient (outside hyperosmotic relative to the inside) of both ionic and nonionic compounds was able to osmotically activate OpuA in the proteoliposomal system. Hypoosmotic medium conditions inhibited the basal activity of the system. The data show that OpuAA and OpuABC are sufficient for osmoregulated transport, indicating that OpuA can act both as osmosensor and osmoregulator. Strikingly, OpuA could also be activated by low concentrations of cationic and anionic amphipaths, which interact with the membrane. This result indicates that activation by a transmembrane osmotic gradient is mediated by changes in membrane properties/protein–lipid interactions. PMID:10860977

  2. The multidrug ABC transporter BmrC/BmrD of Bacillus subtilis is regulated via a ribosome-mediated transcriptional attenuation mechanism

    PubMed Central

    Reilman, Ewoud; Mars, Ruben A. T.; van Dijl, Jan Maarten; Denham, Emma L.

    2014-01-01

    Expression of particular drug transporters in response to antibiotic pressure is a critical element in the development of bacterial multidrug resistance, and represents a serious concern for human health. To obtain a better understanding of underlying regulatory mechanisms, we have dissected the transcriptional activation of the ATP-binding cassette (ABC) transporter BmrC/BmrD of the Gram-positive model bacterium Bacillus subtilis. By using promoter-GFP fusions and live cell array technology, we demonstrate a temporally controlled transcriptional activation of the bmrCD genes in response to antibiotics that target protein synthesis. Intriguingly, bmrCD expression only occurs during the late-exponential and stationary growth stages, irrespective of the timing of the antibiotic challenge. We show that this is due to tight transcriptional control by the transition state regulator AbrB. Moreover, our results show that the bmrCD genes are co-transcribed with bmrB (yheJ), a small open reading frame immediately upstream of bmrC that harbors three alternative stem-loop structures. These stem-loops are apparently crucial for antibiotic-induced bmrCD transcription. Importantly, the antibiotic-induced bmrCD expression requires translation of bmrB, which implies that BmrB serves as a regulatory leader peptide. Altogether, we demonstrate for the first time that a ribosome-mediated transcriptional attenuation mechanism can control the expression of a multidrug ABC transporter. PMID:25217586

  3. ABC transporter Cdr1p harbors charged residues in the intracellular loop and nucleotide-binding domain critical for protein trafficking and drug resistance.

    PubMed

    Shah, Abdul Haseeb; Banerjee, Atanu; Rawal, Manpreet Kaur; Saxena, Ajay Kumar; Mondal, Alok Kumar; Prasad, Rajendra

    2015-08-01

    The ABC transporter Cdr1 protein of Candida albicans, which plays a major role in antifungal resistance, has two transmembrane domains (TMDs) and two nucleotide-binding domains (NBDs). The 12 transmembrane helices of TMDs that are interconnected by extracellular and intracellular loops (ICLs) mainly harbor substrate recognition sites where drugs bind while cytoplasmic NBDs hydrolyze ATP which powers drug efflux. The coupling of ATP hydrolysis to drug transport requires proper communication between NBDs and TMDs typically accomplished by ICLs. This study examines the role of cytoplasmic ICLs of Cdr1p by rationally predicting the critical residues on the basis of their interatomic distances. Among nine pairs that fall within a proximity of <4 Å, an ion pair between K577 of ICL1 and E315 of NBD1 was found to be critical. The substitution, swapping and changing of the length or charge of K577 or E315 by directed mutagenesis led to a misfolded, non-rescuable protein entrapped in intracellular structures. Furthermore, the equipositional ionic pair-forming residues from ICL3 and NBD2 (R1260 and E1014) did not impact protein trafficking. These results point to a new role for ICL/NBD interacting residues in PDR ABC transporters in protein folding and trafficking. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Effects of selected OATP and/or ABC transporter inhibitors on the brain and whole-body distribution of glyburide.

    PubMed

    Tournier, Nicolas; Saba, Wadad; Cisternino, Salvatore; Peyronneau, Marie-Anne; Damont, Annelaure; Goutal, Sébastien; Dubois, Albertine; Dollé, Frédéric; Scherrmann, Jean-Michel; Valette, Héric; Kuhnast, Bertrand; Bottlaender, Michel

    2013-10-01

    Glyburide (glibenclamide, GLB) is a widely prescribed antidiabetic with potential beneficial effects in central nervous system injury and diseases. In vitro studies show that GLB is a substrate of organic anion transporting polypeptide (OATP) and ATP-binding cassette (ABC) transporter families, which may influence GLB distribution and pharmacokinetics in vivo. In the present study, we used [(11)C]GLB positron emission tomography (PET) imaging to non-invasively observe the distribution of GLB at a non-saturating tracer dose in baboons. The role of OATP and P-glycoprotein (P-gp) in [(11)C]GLB whole-body distribution, plasma kinetics, and metabolism was assessed using the OATP inhibitor rifampicin and the dual OATP/P-gp inhibitor cyclosporine. Finally, we used in situ brain perfusion in mice to pinpoint the effect of ABC transporters on GLB transport at the blood-brain barrier (BBB). PET revealed the critical role of OATP on liver [(11)C]GLB uptake and its subsequent impact on [(11)C]GLB metabolism and plasma clearance. OATP-mediated uptake also occurred in the myocardium and kidney parenchyma but not the brain. The inhibition of P-gp in addition to OATP did not further influence [(11)C]GLB tissue and plasma kinetics. At the BBB, the inhibition of both P-gp and breast cancer resistance protein (BCRP) was necessary to demonstrate the role of ABC transporters in limiting GLB brain uptake. This study demonstrates that GLB distribution, metabolism, and elimination are greatly dependent on OATP activity, the first step in GLB hepatic clearance. Conversely, P-gp, BCRP, and probably multidrug resistance protein 4 work in synergy to limit GLB brain uptake.

  5. Iowa ABC connections.

    DOT National Transportation Integrated Search

    2015-06-01

    For several years the Iowa Department of Transportation (DOT), Iowa State University, the Federal Highway Administration, : and several Iowa counties have been working to develop accelerated bridge construction (ABC) concepts, details, and processes....

  6. The phytoestrogen genistein enhances multidrug resistance in breast cancer cell lines by translational regulation of ABC transporters.

    PubMed

    Rigalli, Juan Pablo; Tocchetti, Guillermo Nicolás; Arana, Maite Rocío; Villanueva, Silvina Stella Maris; Catania, Viviana Alicia; Theile, Dirk; Ruiz, María Laura; Weiss, Johanna

    2016-06-28

    Breast cancer is the most frequent malignancy in women. Multidrug resistance due to overexpression of ABC drug transporters is a common cause of chemotherapy failure and disease recurrence. Genistein (GNT) is a phytoestrogen present in soybeans and hormone supplements. We investigated the effect of GNT on the expression and function of ABC transporters in MCF-7 and MDA-MB-231 breast cancer cell lines. Results demonstrated an induction at the protein level of ABCC1 and ABCG2 and of ABCC1 in MCF-7 and MDA-MB-231, respectively. MCF-7 cells showed a concomitant increase in doxorubicin and mitoxantrone efflux and resistance, dependent on ABCG2 activity. ABCC1 induction by GNT in MDA-MB-231 cells modified neither drug efflux nor chemoresistance due to simultaneous acute inhibition of the transporter activity by GNT. All inductions took place at the translational level, as no increment in mRNA was observed and protein increase was prevented by cycloheximide. miR-181a, already demonstrated to inhibit ABCG2 translation, was down-regulated by GNT, explaining translational induction. Effects were independent of classical estrogen receptors. Results suggest potential nutrient-drug interactions that could threaten chemotherapy efficacy, especially in ABCG2-expressing tumors treated with substrates of this transporter. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  7. A wheat ABC transporter contributes to both grain formation and mycotoxin tolerance

    PubMed Central

    Walter, Stephanie; Kahla, Amal; Arunachalam, Chanemoughasoundharam; Perochon, Alexandre; Khan, Mojibur R.; Scofield, Steven R.; Doohan, Fiona M.

    2015-01-01

    The mycotoxin deoxynivalenol (DON) acts as a disease virulence factor for Fusarium fungi, and tolerance of DON enhances wheat resistance to Fusarium head blight (FHB) disease. Two variants of an ATP-binding cassette (ABC) family C transporter gene were cloned from DON-treated wheat mRNA, namely TaABCC3.1 and TaABCC3.2. These represent two of three putative genes identified on chromosomes 3A, 3B, and 3D of the wheat genome sequence. Variant TaABCC3.1 represents the DON-responsive transcript previously associated with DON resistance in wheat. PCR-based mapping and in silico sequence analyses located TaABCC3.1 to the short arm of wheat chromosome 3B (not within the FHB resistance quantitative trait locus Fhb1). In silico analyses of microarray data indicated that TaABCC3 genes are expressed in reproductive tissue and roots, and in response to the DON producer Fusarium graminearum. Gene expression studies showed that TaABCC3.1 is activated as part of the early host response to DON and in response to the FHB defence hormone jasmonic acid. Virus-induced gene silencing (VIGS) confirmed that TaABCC3 genes contributed to DON tolerance. VIGS was performed using two independent viral construct applications: one specifically targeted TaABCC3.1 for silencing, while the other targeted this gene and the chromosome 3A homeologue. In both instances, VIGS resulted in more toxin-induced discoloration of spikelets, compared with the DON effects in non-silenced spikelets at 14 d after toxin treatment (≥2.2-fold increase, P<0.05). Silencing by both VIGS constructs enhanced head ripening, and especially so in DON-treated heads. VIGS of TaABCC3 genes also reduced the grain number by more than 28% (P<0.05), both with and without DON treatment, and the effects were greater for the construct that targeted the two homeologues. Hence, DON-responsive TaABCC3 genes warrant further study to determine their potential as disease resistance breeding targets and their function in grain formation

  8. The ABC transporter ABCG29 is involved in H2O2 tolerance and biocontrol traits in the fungus Clonostachys rosea.

    PubMed

    Dubey, Mukesh; Jensen, Dan Funck; Karlsson, Magnus

    2016-04-01

    For successful biocontrol interactions, biological control organisms must tolerate toxic metabolites produced by themselves or plant pathogens during mycoparasitic/antagonistic interactions, by host plant during colonization of the plant, and xenobiotics present in the environment. ATP-binding cassette (ABC) transporters can play a significant role in tolerance of toxic compounds by mediating active transport across the cellular membrane. This paper reports on functional characterization of an ABC transporter ABCG29 in the biocontrol fungus Clonostachys rosea strain IK726. Gene expression analysis showed induced expression of abcG29 during exposure to the Fusarium spp. mycotoxin zearalenone (ZEA) and the fungicides Cantus, Chipco Green and Apron. Expression of abcG29 in C. rosea was significantly higher during C. rosea-C. rosea (Cr-Cr) interaction or in exposure to C. rosea culture filtrate for 2 h, compared to interaction with Fusarium graminearum or 2 h exposure to F. graminearum culture filtrate. In contrast with gene expression data, ΔabcG29 strains did not display reduced tolerance towards ZEA, fungicides or chemical agents known for inducing oxidative, cell wall or osmotic stress, compared to C. rosea WT. The exception was a significant reduction in tolerance to H2O2 (10 mM) in ΔabcG29 strains when conidia were used as an inoculum. The antagonistic ability of ΔabcG29 strains towards F. graminearum, Fusarium oxysporum or Botrytis cinerea in dual plate assays were not different compared with WT. However, in biocontrol assays ΔabcG29 strains displayed reduced ability to protect Arabidopsis thaliana leaves from B. cinerea, and barley seedling from F. graminearum as measured by an A. thaliana detached leaf assay and a barley foot rot disease assay, respectively. These data show that the ABCG29 is dispensable for ZEA and fungicides tolerance, and antagonism but not H2O2 tolerance and biocontrol effects in C. rosea.

  9. An ABC Transporter System of Yersinia pestis Allows Utilization of Chelated Iron by Escherichia coli SAB11

    PubMed Central

    Bearden, Scott W.; Staggs, Teanna M.; Perry, Robert D.

    1998-01-01

    The acquisition of iron is an essential component in the pathogenesis of Yersinia pestis, the agent of bubonic and pneumonic plague. A cosmid library derived from the genomic DNA of Y. pestis KIM6+ was used for transduction of an Escherichia coli mutant (SAB11) defective in the biosynthesis of the siderophore enterobactin. Recombinant plasmids which had a common 13-kb BamHI fragment were isolated from SAB11 transductants in which growth but not enterobactin synthesis was restored on media containing the iron chelator EDDA [ethylenediamine-di(o-hydroxyphenyl acetic acid)]. Subcloning and transposon mutagenesis revealed a 5.6-kb region, designated yfe, essential for SAB11 growth stimulation. In vitro transcription-translation analysis identified polypeptides of 18, 29.5, 32, and 33 kDa encoded by the yfe locus. Sequence analysis shows this locus to be comprised of five genes in two separate operons which have potential Fur-binding sequences in both promoters. A putative polycistronic operon, yfeABCD, is Fur regulated and responds to iron and manganese. A functional Fur protein is required for the observed manganese repression of this operon. This operon encodes polypeptides which have strong similarity to the ATP-binding cassette (ABC) family of transporters and include a periplasmic binding protein (YfeA), an ATP-binding protein (YfeB), and two integral membrane proteins (YfeC and -D), which likely function in the acquisition of inorganic iron and possibly other ions. The ∼21-kDa protein encoded by the separately transcribed yfeE gene may be located in the cell envelope, since a yfeE::TnphoA fusion is PhoA+. Mutations in this gene abrogate growth of SAB11 on iron-chelated media. PMID:9495751

  10. An ABC transporter system of Yersinia pestis allows utilization of chelated iron by Escherichia coli SAB11.

    PubMed

    Bearden, S W; Staggs, T M; Perry, R D

    1998-03-01

    The acquisition of iron is an essential component in the pathogenesis of Yersinia pestis, the agent of bubonic and pneumonic plague. A cosmid library derived from the genomic DNA of Y. pestis KIM6+ was used for transduction of an Escherichia coli mutant (SAB11) defective in the biosynthesis of the siderophore enterobactin. Recombinant plasmids which had a common 13-kb BamHI fragment were isolated from SAB11 transductants in which growth but not enterobactin synthesis was restored on media containing the iron chelator EDDA [ethylenediamine-di(o-hydroxyphenyl acetic acid)]. Subcloning and transposon mutagenesis revealed a 5.6-kb region, designated yfe, essential for SAB11 growth stimulation. In vitro transcription-translation analysis identified polypeptides of 18, 29.5, 32, and 33 kDa encoded by the yfe locus. Sequence analysis shows this locus to be comprised of five genes in two separate operons which have potential Fur-binding sequences in both promoters. A putative polycistronic operon, yfeABCD, is Fur regulated and responds to iron and manganese. A functional Fur protein is required for the observed manganese repression of this operon. This operon encodes polypeptides which have strong similarity to the ATP-binding cassette (ABC) family of transporters and include a periplasmic binding protein (YfeA), an ATP-binding protein (YfeB), and two integral membrane proteins (YfeC and -D), which likely function in the acquisition of inorganic iron and possibly other ions. The approximately 21-kDa protein encoded by the separately transcribed yfeE gene may be located in the cell envelope, since a yfeE::TnphoA fusion is PhoA+. Mutations in this gene abrogate growth of SAB11 on iron-chelated media.

  11. Molecular cloning and expression profile of an ATP-binding cassette (ABC) transporter gene from the hemipteran insect Nilaparvata lugens.

    PubMed

    Zha, W J; Li, S H; Zhou, L; Chen, Z J; Liu, K; Yang, G C; Hu, G; He, G C; You, A Q

    2015-03-30

    The ATP-binding cassette (ABC) transporters belong to a large superfamily of proteins that have important physiological functions in all living organisms. In insects, ABC transporters have important functions in the transport of molecules, and are also involved in insecticide resistance, metabolism, and development. In this study, the Nilaparvata lugens Stal (Hemiptera: Delphacidae) ABCG (NlABCG) gene was identified and characterized. The complete mRNA sequence of NlABCG was 2608-bp long, with an open reading frame of 2064 bp encoding a protein comprised of 687 amino acids. The conserved regions include three N-glycosylation and 34 phosphorylation sites, as well as seven transmembrane domains. The amino acid identity with the closely related species Acyrthosiphon pisum was 42.8%. Developmental expression analysis using quantitative real-time reverse transcriptase PCR suggested that the NlABCG transcript was expressed at all developmental stages of N. lugens. The lowest expression of NlABCG was in the 1st instar, and levels increased with larval growth. The transcript profiles of NlABCG were analyzed in various tissues from a 5th instar nymph, and the highest expression was observed in the midgut. These results suggest that the sequence, characteristics, and expression of NlABCG are highly conserved, and basic information is provided for its functional analysis.

  12. Drosophila ABC Transporter DmHMT-1 Confers Tolerance to Cadmium.

    USDA-ARS?s Scientific Manuscript database

    Half molecule ATP-binding cassette transporters of the HMT1(heavy metal tolerance factor 1)subfamily are required for Cd2+ tolerance in Schizosaccharomyces pombe, Caenorhabditis elegans and Chlamydomonas reinhardtii, and have homologs in other species, including plants and humans. Based on studies i...

  13. Polymorphisms in ABC Transporter Genes and Concentrations of Mercury in Newborns – Evidence from Two Mediterranean Birth Cohorts

    PubMed Central

    Llop, Sabrina; Engström, Karin; Ballester, Ferran; Franforte, Elisa; Alhamdow, Ayman; Pisa, Federica; Tratnik, Janja Snoj; Mazej, Datja; Murcia, Mario; Rebagliato, Marisa; Bustamante, Mariona; Sunyer, Jordi; Sofianou-Katsoulis, Αikaterini; Prasouli, Alexia; Antonopoulou, Eleni; Antoniadou, Ioanna; Nakou, Sheena; Barbone, Fabio; Horvat, Milena; Broberg, Karin

    2014-01-01

    Background The genetic background may influence methylmercury (MeHg) metabolism and neurotoxicity. ATP binding cassette (ABC) transporters actively transport various xenobiotics across biological membranes. Objective To investigate the role of ABC polymorphisms as modifiers of prenatal exposure to MeHg. Methods The study population consisted of participants (n = 1651) in two birth cohorts, one in Italy and Greece (PHIME) and the other in Spain (INMA). Women were recruited during pregnancy in Italy and Spain, and during the perinatal period in Greece. Total mercury concentrations were measured in cord blood samples by atomic absorption spectrometry. Maternal fish intake during pregnancy was determined from questionnaires. Polymorphisms (n = 5) in the ABC genes ABCA1, ABCB1, ABCC1 and ABCC2 were analysed in both cohorts. Results ABCB1 rs2032582, ABCC1 rs11075290, and ABCC2 rs2273697 modified the associations between maternal fish intake and cord blood mercury concentrations. The overall interaction coefficient between rs2032582 and log2-transformed fish intake was negative for carriers of GT (β = −0.29, 95%CI −0.47, −0.12) and TT (β = −0.49, 95%CI −0.71, −0.26) versus GG, meaning that for a doubling in fish intake of the mothers, children with the rs2032582 GG genotype accumulated 35% more mercury than children with TT. For rs11075290, the interaction coefficient was negative for carriers of TC (β = −0.12, 95%CI −0.33, 0.09), and TT (β = −0.28, 95%CI −0.51, −0.06) versus CC. For rs2273697, the interaction coefficient was positive when combining GA+AA (β = 0.16, 95%CI 0.01, 0.32) versus GG. Conclusion The ABC transporters appear to play a role in accumulation of MeHg during early development. PMID:24831289

  14. Inactivation of the Ecs ABC transporter of Staphylococcus aureus attenuates virulence by altering composition and function of bacterial wall.

    PubMed

    Jonsson, Ing-Marie; Juuti, Jarmo T; François, Patrice; AlMajidi, Rana; Pietiäinen, Milla; Girard, Myriam; Lindholm, Catharina; Saller, Manfred J; Driessen, Arnold J M; Kuusela, Pentti; Bokarewa, Maria; Schrenzel, Jacques; Kontinen, Vesa P

    2010-12-02

    Ecs is an ATP-binding cassette (ABC) transporter present in aerobic and facultative anaerobic gram-positive Firmicutes. Inactivation of Bacillus subtilis Ecs causes pleiotropic changes in the bacterial phenotype including inhibition of intramembrane proteolysis. The molecule(s) transported by Ecs is (are) still unknown. In this study we mutated the ecsAB operon in two Staphylococcus aureus strains, Newman and LS-1. Phenotypic and functional characterization of these Ecs deficient mutants revealed a defect in growth, increased autolysis and lysostaphin sensitivity, altered composition of cell wall proteins including the precursor form of staphylokinase and an altered bacterial surface texture. DNA microarray analysis indicated that the Ecs deficiency changed expression of the virulence factor regulator protein Rot accompanied by differential expression of membrane transport proteins, particularly ABC transporters and phosphate-specific transport systems, protein A, adhesins and capsular polysaccharide biosynthesis proteins. Virulence of the ecs mutants was studied in a mouse model of hematogenous S. aureus infection. Mice inoculated with the ecs mutant strains developed markedly milder infections than those inoculated with the wild-type strains and had consequently lower mortality, less weight loss, milder arthritis and decreased persistence of staphylococci in the kidneys. The ecs mutants had higher susceptibility to ribosomal antibiotics and plant alkaloids chelerythrine and sanguinarine. Our results show that Ecs is essential for staphylococcal virulence and antimicrobial resistance probably since the transport function of Ecs is essential for the normal structure and function of the cell wall. Thus targeting Ecs may be a new approach in combating staphylococcal infection.

  15. Application of fluorescent dye substrates for functional characterization of ABC multidrug transporters at a single cell level.

    PubMed

    Nerada, Zsuzsanna; Hegyi, Zoltán; Szepesi, Áron; Tóth, Szilárd; Hegedüs, Csilla; Várady, György; Matula, Zsolt; Homolya, László; Sarkadi, Balázs; Telbisz, Ágnes

    2016-09-01

    ABC multidrug transporters are key players in cancer multidrug resistance and in determining the ADME-Tox properties of drugs and xenobiotics. The most sensitive and specific detection of these transporters is based on functional assays. Assessment of the transporter-dependent reduction of cellular uptake of the fluorescent dyes, such as Hoechst 33342 (Ho) and more recently DyeCycle Violet (DCV), have been widely advocated for the characterization of both ABCB1 and ABCG2 multidrug transporters. Detailed comparison of these supravital DNA-binding dyes revealed that DCV is less toxic to ABCG2- and ABCB1-expressing cells than Ho. ATPase measurements imply that DCV and Ho are similarly handled by ABCB1, whereas ABCG2 seems to transport DVC more effectively. In addition, we have developed an image-based high content microscopy screening method for simultaneous in situ measurement of the cellular activity and expression of the ABCG2 multidrug transporter. We demonstrated the applicability of this method for identifying ABCG2-positive cells in heterogeneous cell population by a single dye uptake measurement. These results may promote multidrug transporter studies at a single cell level and allow the quantitative detection of clinically important drug-resistant sub-populations. © 2016 International Society for Advancement of Cytometry. © 2016 International Society for Advancement of Cytometry.

  16. The multidrug ABC transporter BmrC/BmrD of Bacillus subtilis is regulated via a ribosome-mediated transcriptional attenuation mechanism.

    PubMed

    Reilman, Ewoud; Mars, Ruben A T; van Dijl, Jan Maarten; Denham, Emma L

    2014-10-01

    Expression of particular drug transporters in response to antibiotic pressure is a critical element in the development of bacterial multidrug resistance, and represents a serious concern for human health. To obtain a better understanding of underlying regulatory mechanisms, we have dissected the transcriptional activation of the ATP-binding cassette (ABC) transporter BmrC/BmrD of the Gram-positive model bacterium Bacillus subtilis. By using promoter-GFP fusions and live cell array technology, we demonstrate a temporally controlled transcriptional activation of the bmrCD genes in response to antibiotics that target protein synthesis. Intriguingly, bmrCD expression only occurs during the late-exponential and stationary growth stages, irrespective of the timing of the antibiotic challenge. We show that this is due to tight transcriptional control by the transition state regulator AbrB. Moreover, our results show that the bmrCD genes are co-transcribed with bmrB (yheJ), a small open reading frame immediately upstream of bmrC that harbors three alternative stem-loop structures. These stem-loops are apparently crucial for antibiotic-induced bmrCD transcription. Importantly, the antibiotic-induced bmrCD expression requires translation of bmrB, which implies that BmrB serves as a regulatory leader peptide. Altogether, we demonstrate for the first time that a ribosome-mediated transcriptional attenuation mechanism can control the expression of a multidrug ABC transporter. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  17. Investigating the dynamic nature of the ABC transporters: ABCB1 and MsbA as examples for the potential synergies of MD theory and EPR applications.

    PubMed

    Stockner, Thomas; Mullen, Anna; MacMillan, Fraser

    2015-10-01

    ABC transporters are primary active transporters found in all kingdoms of life. Human multidrug resistance transporter ABCB1, or P-glycoprotein, has an extremely broad substrate spectrum and confers resistance against chemotherapy drug treatment in cancer cells. The bacterial ABC transporter MsbA is a lipid A flippase and a homolog to the human ABCB1 transporter, with which it partially shares its substrate spectrum. Crystal structures of MsbA and ABCB1 have been solved in multiple conformations, providing a glimpse into the possible conformational changes the transporter could be going through during the transport cycle. Crystal structures are inherently static, while a dynamic picture of the transporter in motion is needed for a complete understanding of transporter function. Molecular dynamics (MD) simulations and electron paramagnetic resonance (EPR) spectroscopy can provide structural information on ABC transporters, but the strength of these two methods lies in the potential to characterise the dynamic regime of these transporters. Information from the two methods is quite complementary. MD simulations provide an all atom dynamic picture of the time evolution of the molecular system, though with a narrow time window. EPR spectroscopy can probe structural, environmental and dynamic properties of the transporter in several time regimes, but only through the attachment sites of an exogenous spin label. In this review the synergistic effects that can be achieved by combining the two methods are highlighted, and a brief methodological background is also presented. © 2015 Authors; published by Portland Press Limited.

  18. Profiling of ABC transporters ABCB5, ABCF2 and nestin-positive stem cells in nevi, in situ and invasive melanoma.

    PubMed

    Setia, Namrata; Abbas, Ossama; Sousa, Yessica; Garb, Jane L; Mahalingam, Meera

    2012-08-01

    Distinct ABCB5 forms and ABCF2, members of the ATP-binding cassette (ABC) superfamily of transporters, are normally expressed in various tissues and cells, and enhanced expression of both has been demonstrated in select cancers. In melanoma cell lines, gene expression profiling of ABC transporters has revealed enhanced expression of melanocyte-specific ABCB5 and ABCF2 proteins. Given this, our primary aim was to ascertain immunohistochemical expression of the ABC transporters ABCB5 and ABCF2 and, the stem cell marker, nestin in a spectrum of benign and malignant nevomelanocytic proliferations, including nevi (n=30), in situ (n=31) and invasive (n=24) primary cutaneous melanomas to assess their role in the stepwise development of malignancy. In addition, their expression was compared with established melanoma prognosticators to ascertain their utility as independent prognosticators. A semiquantitative scoring system was utilized by deriving a cumulative score (based on percentage positivity cells and intensity of expression) and statistical analyses was carried out using analysis of variance with linear contrasts. Mean cumulative score in nevi, in situ and invasive melanoma were as follows: 3.8, 4.4 and 5.3 for ABCB5, respectively (P<0.005 for all), and 4.6, 4.6 and 5.3 for nestin, respectively (P=not significant for all). No appreciable expression of ABCF2 was noted in any of the groups. While ulcerated lesions of melanoma demonstrated lower levels of expression of ABCB5 and nestin than non-ulcerated lesions, and nestin expression was lower in lesions with mitoses >1, after controlling for the presence of ulceration and mitotic activity, the expression of both proteins did not significantly correlate with known melanoma prognosticators. The gradual increase in the expression of ABCB5 from benign nevus to in situ to invasive melanoma suggests that it plays a role in melanomagenesis. On the basis of our findings, a prospective study with follow-up data is required to

  19. Environmental Conditions Influence Induction of Key ABC-Transporter Genes Affecting Glyphosate Resistance Mechanism in Conyza canadensis

    PubMed Central

    Tani, Eleni; Chachalis, Demosthenis; Travlos, Ilias S.; Bilalis, Dimitrios

    2016-01-01

    Conyza canadensis has been reported to be the most frequent weed species that evolved resistance to glyphosate in various parts of the world. The objective of the present study was to investigate the effect of environmental conditions (temperature and light) on the expression levels of the EPSPS gene and two major ABC-transporter genes (M10 and M11) on glyphosate susceptible (GS) and glyphosate resistant (GR) horseweed populations, collected from several regions across Greece. Real-time PCR was conducted to determine the expression level of the aforementioned genes when glyphosate was applied at normal (1×; 533 g·a.e.·ha−1) and high rates (4×, 8×), measured at an early one day after treatment (DAT) and a later stage (four DAT) of expression. Plants were exposed to light or dark conditions, at three temperature regimes (8, 25, 35 °C). GR plants were made sensitive when exposed to 8 °C with light; those sensitized plants behaved biochemically (shikimate accumulation) and molecularly (expression of EPSPS and ABC-genes) like the GS plants. Results from the current study show the direct link between the environmental conditions and the induction level of the above key genes that likely affect the efficiency of the proposed mechanism of glyphosate resistance. PMID:27104532

  20. Environmental Conditions Influence Induction of Key ABC-Transporter Genes Affecting Glyphosate Resistance Mechanism in Conyza canadensis.

    PubMed

    Tani, Eleni; Chachalis, Demosthenis; Travlos, Ilias S; Bilalis, Dimitrios

    2016-04-20

    Conyza canadensis has been reported to be the most frequent weed species that evolved resistance to glyphosate in various parts of the world. The objective of the present study was to investigate the effect of environmental conditions (temperature and light) on the expression levels of the EPSPS gene and two major ABC-transporter genes (M10 and M11) on glyphosate susceptible (GS) and glyphosate resistant (GR) horseweed populations, collected from several regions across Greece. Real-time PCR was conducted to determine the expression level of the aforementioned genes when glyphosate was applied at normal (1×; 533 g·a.e.·ha(-1)) and high rates (4×, 8×), measured at an early one day after treatment (DAT) and a later stage (four DAT) of expression. Plants were exposed to light or dark conditions, at three temperature regimes (8, 25, 35 °C). GR plants were made sensitive when exposed to 8 °C with light; those sensitized plants behaved biochemically (shikimate accumulation) and molecularly (expression of EPSPS and ABC-genes) like the GS plants. Results from the current study show the direct link between the environmental conditions and the induction level of the above key genes that likely affect the efficiency of the proposed mechanism of glyphosate resistance.

  1. Iowa ABC connections : [tech transfer summary].

    DOT National Transportation Integrated Search

    2015-06-01

    The Iowa Department of Transportation (DOT) and other organizations have : been developing accelerated bridge construction (ABC) concepts, details, and : processes, and Iowa has come to be viewed as a national leader in the area of : ABC. However, th...

  2. Secondary Metabolites from Plants Inhibiting ABC Transporters and Reversing Resistance of Cancer Cells and Microbes to Cytotoxic and Antimicrobial Agents

    PubMed Central

    Wink, Michael; Ashour, Mohamed L.; El-Readi, Mahmoud Zaki

    2012-01-01

    Fungal, bacterial, and cancer cells can develop resistance against antifungal, antibacterial, or anticancer agents. Mechanisms of resistance are complex and often multifactorial. Mechanisms include: (1) Activation of ATP-binding cassette (ABC) transporters, such as P-gp, which pump out lipophilic compounds that have entered a cell, (2) Activation of cytochrome p450 oxidases which can oxidize lipophilic agents to make them more hydrophilic and accessible for conjugation reaction with glucuronic acid, sulfate, or amino acids, and (3) Activation of glutathione transferase, which can conjugate xenobiotics. This review summarizes the evidence that secondary metabolites (SM) of plants, such as alkaloids, phenolics, and terpenoids can interfere with ABC transporters in cancer cells, parasites, bacteria, and fungi. Among the active natural products several lipophilic terpenoids [monoterpenes, diterpenes, triterpenes (including saponins), steroids (including cardiac glycosides), and tetraterpenes] but also some alkaloids (isoquinoline, protoberberine, quinoline, indole, monoterpene indole, and steroidal alkaloids) function probably as competitive inhibitors of P-gp, multiple resistance-associated protein 1, and Breast cancer resistance protein in cancer cells, or efflux pumps in bacteria (NorA) and fungi. More polar phenolics (phenolic acids, flavonoids, catechins, chalcones, xanthones, stilbenes, anthocyanins, tannins, anthraquinones, and naphthoquinones) directly inhibit proteins forming several hydrogen and ionic bonds and thus disturbing the 3D structure of the transporters. The natural products may be interesting in medicine or agriculture as they can enhance the activity of active chemotherapeutics or pesticides or even reverse multidrug resistance, at least partially, of adapted and resistant cells. If these SM are applied in combination with a cytotoxic or antimicrobial agent, they may reverse resistance in a synergistic fashion. PMID:22536197

  3. Salinomycin overcomes ABC transporter-mediated multidrug and apoptosis resistance in human leukemia stem cell-like KG-1a cells

    SciTech Connect

    Fuchs, Dominik; Institute of Immunology, University of Heidelberg, Im Neuenheimer Feld 305, D-69120 Heidelberg; Daniel, Volker

    2010-04-16

    Leukemia stem cells are known to exhibit multidrug resistance by expression of ATP-binding cassette (ABC) transporters which constitute transmembrane proteins capable of exporting a wide variety of chemotherapeutic drugs from the cytosol. We show here that human promyeloblastic leukemia KG-1a cells exposed to the histone deacetylase inhibitor phenylbutyrate resemble many characteristics of leukemia stem cells, including expression of functional ABC transporters such as P-glycoprotein, BCRP and MRP8. Consequently, KG-1a cells display resistance to the induction of apoptosis by various chemotherapeutic drugs. Resistance to apoptosis induction by chemotherapeutic drugs can be reversed by cyclosporine A, which effectively inhibits the activity ofmore » P-glycoprotein and BCRP, thus demonstrating ABC transporter-mediated drug resistance in KG-1a cells. However, KG-1a are highly sensitive to apoptosis induction by salinomycin, a polyether ionophore antibiotic that has recently been shown to kill human breast cancer stem cell-like cells and to induce apoptosis in human cancer cells displaying multiple mechanisms of drug and apoptosis resistance. Whereas KG-1a cells can be adapted to proliferate in the presence of apoptosis-inducing concentrations of bortezomib and doxorubicin, salinomycin does not permit long-term adaptation of the cells to apoptosis-inducing concentrations. Thus, salinomycin should be regarded as a novel and effective agent for the elimination of leukemia stem cells and other tumor cells exhibiting ABC transporter-mediated multidrug resistance.« less

  4. Conserved ABC Transport System Regulated by the General Stress Response Pathways of Alpha- and Gammaproteobacteria.

    PubMed

    Herrou, Julien; Willett, Jonathan W; Czyż, Daniel M; Babnigg, Gyorgy; Kim, Youngchang; Crosson, Sean

    2017-03-01

    Brucella abortus σ E1 is an EcfG family sigma factor that regulates the transcription of dozens of genes in response to diverse stress conditions and is required for maintenance of chronic infection in a mouse model. A putative ATP-binding cassette transporter operon, bab1_0223-bab1_0226 , is among the most highly activated gene sets in the σ E1 regulon. The proteins encoded by the operon resemble quaternary ammonium-compatible solute importers but are most similar in sequence to the broadly conserved YehZYXW system, which remains largely uncharacterized. Transcription of yehZYXW is activated by the general stress sigma factor σ S in Enterobacteriaceae , which suggests a functional role for this transport system in bacterial stress response across the classes Alphaproteobacteria and Gammaproteobacteria We present evidence that B. abortus YehZYXW does not function as an importer of known compatible solutes under physiological conditions and does not contribute to the virulence defect of a σ E1 -null strain. The sole in vitro phenotype associated with genetic disruption of this putative transport system is reduced growth in the presence of high Li + ion concentrations. A crystal structure of B. abortus YehZ revealed a class II periplasmic binding protein fold with significant structural homology to Archaeoglobus fulgidus ProX, which binds glycine betaine. However, the structure of the YehZ ligand-binding pocket is incompatible with high-affinity binding to glycine betaine. This is consistent with weak measured binding of YehZ to glycine betaine and related compatible solutes. We conclude that YehZYXW is a conserved, stress-regulated transport system that is phylogenetically and functionally distinct from quaternary ammonium-compatible solute importers. IMPORTANCE Brucella abortus σ E1 regulates transcription in response to stressors encountered in its mammalian host and is necessary for maintenance of chronic infection in a mouse model. The functions of the

  5. Conserved ABC Transport System Regulated by the General Stress Response Pathways of Alpha- and Gammaproteobacteria

    SciTech Connect

    Herrou, Julien; Willett, Jonathan W.; Czyż, Daniel M.

    ABSTRACT Brucella abortusσ E1is an EcfG family sigma factor that regulates the transcription of dozens of genes in response to diverse stress conditions and is required for maintenance of chronic infection in a mouse model. A putative ATP-binding cassette transporter operon,bab1_0223-bab1_0226, is among the most highly activated gene sets in the σ E1regulon. The proteins encoded by the operon resemble quaternary ammonium-compatible solute importers but are most similar in sequence to the broadly conserved YehZYXW system, which remains largely uncharacterized. Transcription ofyehZYXWis activated by the general stress sigma factor σ SinEnterobacteriaceae, which suggests a functional role for this transport systemmore » in bacterial stress response across the classesAlphaproteobacteriaandGammaproteobacteria. We present evidence thatB. abortusYehZYXW does not function as an importer of known compatible solutes under physiological conditions and does not contribute to the virulence defect of a σ E1-null strain. The solein vitrophenotype associated with genetic disruption of this putative transport system is reduced growth in the presence of high Li +ion concentrations. A crystal structure ofB. abortusYehZ revealed a class II periplasmic binding protein fold with significant structural homology toArchaeoglobus fulgidusProX, which binds glycine betaine. However, the structure of the YehZ ligand-binding pocket is incompatible with high-affinity binding to glycine betaine. This is consistent with weak measured binding of YehZ to glycine betaine and related compatible solutes. We conclude that YehZYXW is a conserved, stress-regulated transport system that is phylogenetically and functionally distinct from quaternary ammonium-compatible solute importers. IMPORTANCEBrucella abortusσ E1regulates transcription in response to stressors encountered in its mammalian host and is necessary for maintenance of chronic infection in a mouse model. The functions of the majority of

  6. Separating the roles of acropetal and basipetal auxin transport on gravitropism with mutations in two Arabidopsis multidrug resistance-like ABC transporter genes.

    PubMed

    Lewis, Daniel R; Miller, Nathan D; Splitt, Bessie L; Wu, Guosheng; Spalding, Edgar P

    2007-06-01

    Two Arabidopsis thaliana ABC transporter genes linked to auxin transport by various previous results were studied in a reverse-genetic fashion. Mutations in Multidrug Resistance-Like1 (MDR1) reduced acropetal auxin transport in roots by 80% without affecting basipetal transport. Conversely, mutations in MDR4 blocked 50% of basipetal transport without affecting acropetal transport. Developmental and auxin distribution phenotypes associated with these altered auxin flows were studied with a high-resolution morphometric system and confocal microscopy, respectively. Vertically grown mdr1 roots produced positive and negative curvatures threefold greater than the wild type, possibly due to abnormal auxin distribution observed in the elongation zone. However, upon 90 degrees reorientation, mdr1 gravitropism was inseparable from the wild type. Thus, acropetal auxin transport maintains straight growth but contributes surprisingly little to gravitropism. Conversely, vertically maintained mdr4 roots grew as straight as the wild type, but their gravitropism was enhanced. Upon reorientation, curvature in this mutant developed faster, was distributed more basally, and produced a greater total angle than the wild type. An amplified auxin asymmetry may explain the mdr4 hypertropism. Double mutant analysis indicated that the two auxin transport streams are more independent than interdependent. The hypothesis that flavanols regulate MDR-dependent auxin transport was supported by the epistatic relationship of mdr4 to the tt4 phenylpropanoid pathway mutation.

  7. Genome-wide identification of ATP-binding cassette (ABC) transporters and their roles in response to polycyclic aromatic hydrocarbons (PAHs) in the copepod Paracyclopina nana.

    PubMed

    Jeong, Chang-Bum; Kim, Duck-Hyun; Kang, Hye-Min; Lee, Young Hwan; Kim, Hui-Su; Kim, Il-Chan; Lee, Jae-Seong

    2017-02-01

    The ATP-binding cassette (ABC) protein superfamily is one of the largest gene families and is highly conserved in all domains. The ABC proteins play roles in several biological processes, including multi-xenobiotic resistance (MXR), by functioning as transporters in the cellular membrane. They also mediate the cellular efflux of a wide range of substrates against concentration gradients. In this study, 37 ABC genes belonging to eight distinct subfamilies were identified in the marine copepod Paracyclopina nana and annotated based on a phylogenetic analysis. Also, the functions of P-glycoproteins (P-gp) and multidrug resistance-associated proteins (MRPs), conferring MXR, were verified using fluorescent substrates and specific inhibitors. The activities of MXR-mediated ABC proteins and their transcriptional level were examined in response to polyaromatic hydrocarbons (PAHs), main components of the water-accommodated fraction. This study increases the understanding of the protective role of MXR in response to PAHs over the comparative evolution of ABC gene families. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Novel understanding of ABC transporters ABCB1/MDR/P-glycoprotein, ABCC2/MRP2, and ABCG2/BCRP in colorectal pathophysiology

    PubMed Central

    Andersen, Vibeke; Svenningsen, Katrine; Knudsen, Lina Almind; Hansen, Axel Kornerup; Holmskov, Uffe; Stensballe, Allan; Vogel, Ulla

    2015-01-01

    AIM: To evaluate ATP-binding cassette (ABC) transporters in colonic pathophysiology as they had recently been related to colorectal cancer (CRC) development. METHODS: Literature search was conducted on PubMed using combinations of the following terms: ABC transporters, ATP binding cassette transporter proteins, inflammatory bowel disease, ulcerative, colitis, Crohns disease, colorectal cancer, colitis, intestinal inflammation, intestinal carcinogenesis, ABCB1/P-glycoprotein (P-gp/CD243/MDR1), ABCC2/multidrug resistance protein 2 (MRP2) and ABCG2/breast cancer resistance protein (BCRP), Abcb1/Mdr1a, abcc2/Mrp2, abcg2/Bcrp, knock-out mice, tight junction, membrane lipid function. RESULTS: Recently, human studies reported that changes in the levels of ABC transporters were early events in the adenoma-carcinoma sequence leading to CRC. A link between ABCB1, high fat diet and gut microbes in relation to colitis was suggested by the animal studies. The finding that colitis was preceded by altered gut bacterial composition suggests that deletion of Abcb1 leads to fundamental changes of host-microbiota interaction. Also, high fat diet increases the frequency and severity of colitis in specific pathogen-free Abcb1 KO mice. The Abcb1 KO mice might thus serve as a model in which diet/environmental factors and microbes may be controlled and investigated in relation to intestinal inflammation. Potential molecular mechanisms include defective transport of inflammatory mediators and/or phospholipid translocation from one side to the other of the cell membrane lipid bilayer by ABC transporters affecting inflammatory response and/or function of tight junctions, phagocytosis and vesicle trafficking. Also, diet and microbes give rise to molecules which are potential substrates for the ABC transporters and which may additionally affect ABC transporter function through nuclear receptors and transcriptional regulation. Another critical role of ABCB1 was suggested by the finding that

  9. Alzheimer's disease: neuroprogesterone, epoxycholesterol, and ABC transporters as determinants of neurodesmosterol tissue levels and its role in amyloid protein processing.

    PubMed

    Javitt, Norman B

    2013-01-01

    Evidence is emerging that during the development of Alzheimer's disease (AD), changes in the synthesis and metabolism of cholesterol and progesterone are occurring that may or may not affect the progression of the disease. The concept arose from the recognition that dehydrocholesterol 24-reductase (DHCR24/Seladin-1), one of the nine enzymes in the endoplasmic reticulum that determines the transformation of lanosterol to cholesterol, is selectively reduced in late AD. As a consequence, the tissue level of desmosterol increases, affecting the expression of ABC transporters and the structure of lipid rafts, both determinants of amyloid-β processing. However, the former effect is considered beneficial and the latter detrimental to processing. Other determinants of desmosterol tissue levels are 24,25 epoxycholesterol and the ABCG1 and ABCG4 transporters. Progesterone and its metabolites are determinants of tissue levels of desmosterol and several other sterol intermediates in cholesterol synthesis. Animal models indicate marked elevations in the tissue levels of these sterols at early time frames in the progression of neurodegenerative diseases. The low level of neuroprogesterone and metabolites in AD are consonant with the low level of desmosterol and may have a role in amyloid-β processing. The sparse data that has accumulated appears to be a sufficient basis for proposing a systematic evaluation of the biologic roles of sterol intermediates in the slowly progressive neurodegeneration characteristic of AD.

  10. ABC transporters and cytochromes P450 in the human central nervous system: influence on brain pharmacokinetics and contribution to neurodegenerative disorders.

    PubMed

    Dutheil, Fabien; Jacob, Aude; Dauchy, Sandrine; Beaune, Philippe; Scherrmann, Jean-Michel; Declèves, Xavier; Loriot, Marie-Anne

    2010-10-01

    The identification of xenobiotic metabolizing enzymes (i.e., CYP) and transporters (i.e., ABC transporters) (XMET) in the human brain, including the BBB, raises the question whether these transporters and enzymes have specific functions in brain physiology, neuropharmacology and toxicology. Relevant literature was identified using PubMed search articles published up to March 2010. Search terms included 'ABC transporters and P450 or CYP', 'drug metabolism, effect and toxicity' and 'neurodegenerative disease (Alzheimer and Parkinson diseases)' restricted to the field of 'brain or human brain'. This review aims to provide a better understanding of XMET functions in the human brain and show their pharmacological importance for improving drug delivery and efficacy and also for managing their side effects. Finally, the impact of brain XMET activity during neurodegenerative processes is discussed, giving an opportunity to identify new markers of human brain diseases. During the last 2 decades, much evidence concerning the specific distribution patterns of XMET, their induction by xenobiotics and endobiotics and their genetic variations have made cerebral ABC transporters and CYP enzymes key elements in the way individual patients respond to centrally acting drugs.

  11. ABC transporters P-gp and Bcrp do not limit the brain uptake of the novel antipsychotic and anticonvulsant drug cannabidiol in mice

    PubMed Central

    Brzozowska, Natalia; Li, Kong M.; Wang, Xiao Suo; Booth, Jessica; Stuart, Jordyn; McGregor, Iain S.

    2016-01-01

    Cannabidiol (CBD) is currently being investigated as a novel therapeutic for the treatment of CNS disorders like schizophrenia and epilepsy. ABC transporters such as P-glycoprotein (P-gp) and breast cancer resistance protein (Bcrp) mediate pharmacoresistance in these disorders. P-gp and Bcrp are expressed at the blood brain barrier (BBB) and reduce the brain uptake of substrate drugs including various antipsychotics and anticonvulsants. It is therefore important to assess whether CBD is prone to treatment resistance mediated by P-gp and Bcrp. Moreover, it has become common practice in the drug development of CNS agents to screen against ABC transporters to help isolate lead compounds with optimal pharmacokinetic properties. The current study aimed to assess whether P-gp and Bcrp impacts the brain transport of CBD by comparing CBD tissue concentrations in wild-type (WT) mice versus mice devoid of ABC transporter genes. P-gp knockout (Abcb1a/b−∕−), Bcrp knockout (Abcg2−∕−), combined P-gp/Bcrp knockout (Abcb1a/b−∕−Abcg2−∕−) and WT mice were injected with CBD, before brain and plasma samples were collected at various time-points. CBD results were compared with the positive control risperidone and 9-hydroxy risperidone, antipsychotic drugs that are established ABC transporter substrates. Brain and plasma concentrations of CBD were not greater in P-gp, Bcrp or P-gp/Bcrp knockout mice than WT mice. In comparison, the brain/plasma concentration ratios of risperidone and 9-hydroxy risperidone were profoundly higher in P-gp knockout mice than WT mice. These results suggest that CBD is not a substrate of P-gp or Bcrp and may be free from the complication of reduced brain uptake by these transporters. Such findings provide favorable evidence for the therapeutic development of CBD in the treatment of various CNS disorders. PMID:27257556

  12. ABC transporters P-gp and Bcrp do not limit the brain uptake of the novel antipsychotic and anticonvulsant drug cannabidiol in mice.

    PubMed

    Brzozowska, Natalia; Li, Kong M; Wang, Xiao Suo; Booth, Jessica; Stuart, Jordyn; McGregor, Iain S; Arnold, Jonathon C

    2016-01-01

    Cannabidiol (CBD) is currently being investigated as a novel therapeutic for the treatment of CNS disorders like schizophrenia and epilepsy. ABC transporters such as P-glycoprotein (P-gp) and breast cancer resistance protein (Bcrp) mediate pharmacoresistance in these disorders. P-gp and Bcrp are expressed at the blood brain barrier (BBB) and reduce the brain uptake of substrate drugs including various antipsychotics and anticonvulsants. It is therefore important to assess whether CBD is prone to treatment resistance mediated by P-gp and Bcrp. Moreover, it has become common practice in the drug development of CNS agents to screen against ABC transporters to help isolate lead compounds with optimal pharmacokinetic properties. The current study aimed to assess whether P-gp and Bcrp impacts the brain transport of CBD by comparing CBD tissue concentrations in wild-type (WT) mice versus mice devoid of ABC transporter genes. P-gp knockout (Abcb1a/b (-∕-)), Bcrp knockout (Abcg2 (-∕-)), combined P-gp/Bcrp knockout (Abcb1a/b (-∕-) Abcg2 (-∕-)) and WT mice were injected with CBD, before brain and plasma samples were collected at various time-points. CBD results were compared with the positive control risperidone and 9-hydroxy risperidone, antipsychotic drugs that are established ABC transporter substrates. Brain and plasma concentrations of CBD were not greater in P-gp, Bcrp or P-gp/Bcrp knockout mice than WT mice. In comparison, the brain/plasma concentration ratios of risperidone and 9-hydroxy risperidone were profoundly higher in P-gp knockout mice than WT mice. These results suggest that CBD is not a substrate of P-gp or Bcrp and may be free from the complication of reduced brain uptake by these transporters. Such findings provide favorable evidence for the therapeutic development of CBD in the treatment of various CNS disorders.

  13. Functional Interaction between the Cytoplasmic ABC Protein LptB and the Inner Membrane LptC Protein, Components of the Lipopolysaccharide Transport Machinery in Escherichia coli

    PubMed Central

    Martorana, Alessandra M.; Benedet, Mattia; Maccagni, Elisa A.; Sperandeo, Paola; Villa, Riccardo; Dehò, Gianni

    2016-01-01

    ABSTRACT The assembly of lipopolysaccharide (LPS) in the outer leaflet of the outer membrane (OM) requires the transenvelope Lpt (lipopolysaccharide transport) complex, made in Escherichia coli of seven essential proteins located in the inner membrane (IM) (LptBCFG), periplasm (LptA), and OM (LptDE). At the IM, LptBFG constitute an unusual ATP binding cassette (ABC) transporter, composed by the transmembrane LptFG proteins and the cytoplasmic LptB ATPase, which is thought to extract LPS from the IM and to provide the energy for its export across the periplasm to the cell surface. LptC is a small IM bitopic protein that binds to LptBFG and recruits LptA via its N- and C-terminal regions, and its role in LPS export is not completely understood. Here, we show that the expression level of lptB is a critical factor for suppressing lethality of deletions in the C-terminal region of LptC and the functioning of a hybrid Lpt machinery that carries Pa-LptC, the highly divergent LptC orthologue from Pseudomonas aeruginosa. We found that LptB overexpression stabilizes C-terminally truncated LptC mutant proteins, thereby allowing the formation of a sufficient amount of stable IM complexes to support growth. Moreover, the LptB level seems also critical for the assembly of IM complexes carrying Pa-LptC which is otherwise defective in interactions with the E. coli LptFG components. Overall, our data suggest that LptB and LptC functionally interact and support a model whereby LptB plays a key role in the assembly of the Lpt machinery. IMPORTANCE The asymmetric outer membrane (OM) of Gram-negative bacteria contains in its outer leaflet an unusual glycolipid, the lipopolysaccharide (LPS). LPS largely contributes to the peculiar permeability barrier properties of the OM that prevent the entry of many antibiotics, thus making Gram-negative pathogens difficult to treat. In Escherichia coli the LPS transporter (the Lpt machine) is made of seven essential proteins (LptABCDEFG) that form a

  14. The ABCs of membrane transporters in health and disease (SLC series): Introduction☆☆☆

    PubMed Central

    Hediger, Matthias A.; Clémençon, Benjamin; Burrier, Robert E.; Bruford, Elspeth A.

    2013-01-01

    The field of transport biology has steadily grown over the past decade and is now recognized as playing an important role in manifestation and treatment of disease. The SLC (solute carrier) gene series has grown to now include 52 families and 395 transporter genes in the human genome. A list of these genes can be found at the HUGO Gene Nomenclature Committee (HGNC) website (see www.genenames.org/genefamilies/SLC). This special issue features mini-reviews for each of these SLC families written by the experts in each field. The existing online resource for solute carriers, the Bioparadigms SLC Tables (www.bioparadigms.org), has been updated and significantly extended with additional information and cross-links to other relevant databases, and the nomenclature used in this database has been validated and approved by the HGNC. In addition, the Bioparadigms SLC Tables functionality has been improved to allow easier access by the scientific community. This introduction includes: an overview of all known SLC and “non-SLC” transporter genes; a list of transporters of water soluble vitamins; a summary of recent progress in the structure determination of transporters (including GLUT1/SLC2A1); roles of transporters in human diseases and roles in drug approval and pharmaceutical perspectives. PMID:23506860

  15. The novel ABC transporter ABCH1 is a potential target for RNAi-based insect pest control and resistance management.

    PubMed

    Guo, Zhaojiang; Kang, Shi; Zhu, Xun; Xia, Jixing; Wu, Qingjun; Wang, Shaoli; Xie, Wen; Zhang, Youjun

    2015-09-03

    Insect pests cause serious crop damage and develop high-level resistance to chemical insecticides and Bacillus thuringiensis (Bt) insecticidal Cry toxins. A new promising approach for controlling them and overcoming this resistance is RNA interference (RNAi). The RNAi-based insect control strategy depends on the selection of suitable target genes. In this study, we cloned and characterized a novel ABC transporter gene PxABCH1 in diamondback moth, Plutella xylostella (L.). Phylogenetic analysis showed that PxABCH1 is closely related to ABCA and ABCG subfamily members. Spatial-temporal expression detection revealed that PxABCH1 was expressed in all tissues and developmental stages, and highest expressed in head and male adult. Midgut sequence variation and expression analyses of PxABCH1 in all the susceptible and Bt-resistant P. xylostella strains and the functional analysis by sublethal RNAi demonstrated that Cry1Ac resistance was independent of this gene. Silencing of PxABCH1 by a relatively high dose of dsRNA dramatically reduced its expression and resulted in larval and pupal lethal phenotypes in both susceptible and Cry1Ac-resistant P. xylostella strains. To our knowledge, this study provides the first insight into ABCH1 in lepidopterans and reveals it as an excellent target for RNAi-based insect pest control and resistance management.

  16. The novel ABC transporter ABCH1 is a potential target for RNAi-based insect pest control and resistance management

    PubMed Central

    Guo, Zhaojiang; Kang, Shi; Zhu, Xun; Xia, Jixing; Wu, Qingjun; Wang, Shaoli; Xie, Wen; Zhang, Youjun

    2015-01-01

    Insect pests cause serious crop damage and develop high-level resistance to chemical insecticides and Bacillus thuringiensis (Bt) insecticidal Cry toxins. A new promising approach for controlling them and overcoming this resistance is RNA interference (RNAi). The RNAi-based insect control strategy depends on the selection of suitable target genes. In this study, we cloned and characterized a novel ABC transporter gene PxABCH1 in diamondback moth, Plutella xylostella (L.). Phylogenetic analysis showed that PxABCH1 is closely related to ABCA and ABCG subfamily members. Spatial-temporal expression detection revealed that PxABCH1 was expressed in all tissues and developmental stages, and highest expressed in head and male adult. Midgut sequence variation and expression analyses of PxABCH1 in all the susceptible and Bt-resistant P. xylostella strains and the functional analysis by sublethal RNAi demonstrated that Cry1Ac resistance was independent of this gene. Silencing of PxABCH1 by a relatively high dose of dsRNA dramatically reduced its expression and resulted in larval and pupal lethal phenotypes in both susceptible and Cry1Ac-resistant P. xylostella strains. To our knowledge, this study provides the first insight into ABCH1 in lepidopterans and reveals it as an excellent target for RNAi-based insect pest control and resistance management. PMID:26333918

  17. Bombyx mori ABC transporter C2 structures responsible for the receptor function of Bacillus thuringiensis Cry1Aa toxin.

    PubMed

    Tanaka, Shiho; Endo, Haruka; Adegawa, Satomi; Iizuka, Ami; Imamura, Kazuhiro; Kikuta, Shingo; Sato, Ryoichi

    2017-12-01

    Because Bombyx mori ABC transporter C2 (BmABCC2) has 1000-fold higher potential than B. mori cadherin-like protein as a receptor for Bacillus thuringiensis Cry1Aa toxin (Tanaka et al., 2013), the gate-opening ability of the latent pore under six extracellular loops (ECLs) of BmABCC2 was expected to be the reason for its higher potential (Heckel, 2012). In this study, cell swelling assays in Sf9 cells showed that BmABCC2 mutants lacking substrate-excreting activity retained receptor activity, indicating that the gate-opening activity of BmABCC2 is not responsible for Cry1Aa toxicity. The analysis of 29 BmABCC2 mutants demonstrated that 770 DYWL 773 of ECL 4 comprise a putative binding site to Cry1Aa. This suggests that specific toxicity of Cry1Aa toxin to a restricted range of lepidopteran insects is dependent on conservation and variation in the amino acid residues around 770 DYWL 773 of ECL 4 in the ABCC2. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Role of nuclear factor-erythroid 2-related factor 2 (Nrf2) in the transcriptional regulation of brain ABC transporters during acute acetaminophen (APAP) intoxication in mice.

    PubMed

    Ghanem, Carolina I; Rudraiah, Swetha; Bataille, Amy M; Vigo, María B; Goedken, Michael J; Manautou, José E

    2015-04-01

    Changes in expression of liver ABC transporters have been described during acute APAP intoxication. However, the effect of APAP on brain ABC transporters is poorly understood. The aim of this study was to evaluate the effect of APAP on brain ABC transporters expression and the role of the oxidative stress sensor Nrf2. Male C57BL/6J mice were administered APAP (400mg/kg) for analysis of brain mRNA and protein expression of Mrp1-6, Bcrp and P-gp. The results show induction of P-gp, Mrp2 and Mrp4 proteins, with no changes in Bcrp, Mrp1 or Mrp5-6. The protein values were accompanied by corresponding changes in mRNA levels. Additionally, brain Nrf2 nuclear translocation and expression of two Nrf2 target genes, quinone oxidoreductase 1 (Nqo1) and Hemoxygenase 1 (Ho-1), was evaluated at 6, 12 and 24h after APAP treatment. Nrf2 nuclear content increased by 58% at 12h after APAP along with significant increments in mRNA and protein expression of Nqo1 and Ho-1. Furthermore, APAP treated Nrf2 knockout mice did not increase mRNA or protein expression of Mrp2 and Mrp4 as observed in wildtypes. In contrast, P-gp induction by APAP was observed in both genotypes. In conclusion, acute APAP intoxication induces protein expression of brain P-gp, Mrp2 and Mrp4. This study also suggests that brain changes in Mrp2 and Mrp4 expression may be due to in situ Nrf2 activation by APAP, while P-gp induction is independent of Nrf2 function. The functional consequences of these changes in brain ABC transporters by APAP deserve further attention. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. ATP-induced conformational changes of nucleotide-binding domains in an ABC transporter. Importance of the water-mediated entropic force.

    PubMed

    Hayashi, Tomohiko; Chiba, Shuntaro; Kaneta, Yusuke; Furuta, Tadaomi; Sakurai, Minoru

    2014-11-06

    ATP binding cassette (ABC) proteins belong to a superfamily of active transporters. Recent experimental and computational studies have shown that binding of ATP to the nucleotide binding domains (NBDs) of ABC proteins drives the dimerization of NBDs, which, in turn, causes large conformational changes within the transmembrane domains (TMDs). To elucidate the active substrate transport mechanism of ABC proteins, it is first necessary to understand how the NBD dimerization is driven by ATP binding. In this study, we selected MalKs (NBDs of a maltose transporter) as a representative NBD and calculated the free-energy change upon dimerization using molecular mechanics calculations combined with a statistical thermodynamic theory of liquids, as well as a method to calculate the translational, rotational, and vibrational entropy change. This combined method is applied to a large number of snapshot structures obtained from molecular dynamics simulations containing explicit water molecules. The results suggest that the NBD dimerization proceeds with a large gain of water entropy when ATP molecules bind to the NBDs. The energetic gain arising from direct NBD-NBD interactions is canceled by the dehydration penalty and the configurational-entropy loss. ATP hydrolysis induces a loss of the shape complementarity between the NBDs, which leads to the dissociation of the dimer, due to a decrease in the water-entropy gain and an increase in the configurational-entropy loss. This interpretation of the NBD dimerization mechanism in concert with ATP, especially focused on the water-mediated entropy force, is potentially applicable to a wide variety of the ABC transporters.

  20. Structural and functional insights into the lipopolysaccharide ABC transporter LptB2FG.

    PubMed

    Dong, Haohao; Zhang, Zhengyu; Tang, Xiaodi; Paterson, Neil G; Dong, Changjiang

    2017-08-09

    The cell surface of most Gram-negative bacteria contains lipopolysaccharide that is essential for their viability and drug resistance. A 134-kDa protein complex LptB 2 FG is unique among ATP-binding cassette transporters because it extracts lipopolysaccharide from the external leaflet of the inner membrane and propels it along a filament that extends across the periplasm to directly deliver lipopolysaccharide into the external leaflet of the outer membrane. Here we report the crystal structure of the lipopolysaccharide transporter LptB 2 FG from Klebsiella pneumoniae, in which both LptF and LptG are composed of a β-jellyroll-like periplasmic domain and six α-helical segments in the transmembrane domain. LptF and LptG form a central cavity containing highly conserved hydrophobic residues. Structural and functional studies suggest that LptB 2 FG uses an alternating lateral access mechanism to extract lipopolysaccharide and traffic it along the hydrophobic cavity toward the transporter's periplasmic domains.Lipopolysaccharides (LPS) are synthesized at the periplasmic side of the inner membrane of Gram-negative bacteria and are then extracted by the LptB 2 FG complex during the first step of LPS transport to the outer membrane. Here the authors present the LptB 2 FG structure, which supports an alternating lateral access mechanism for LPS extraction.

  1. Identification of Residues in the Lipopolysaccharide ABC Transporter That Coordinate ATPase Activity with Extractor Function

    PubMed Central

    Simpson, Brent W.; Owens, Tristan W.; Orabella, Matthew J.; Davis, Rebecca M.; May, Janine M.; Trauger, Sunia A.

    2016-01-01

    ABSTRACT The surface of most Gram-negative bacteria is covered with lipopolysaccharide (LPS), creating a permeability barrier against toxic molecules, including many antimicrobials. To assemble LPS on their surface, Gram-negative bacteria must extract newly synthesized LPS from the inner membrane, transport it across the aqueous periplasm, and translocate it across the outer membrane. The LptA to -G proteins assemble into a transenvelope complex that transports LPS from the inner membrane to the cell surface. The Lpt system powers LPS transport from the inner membrane by using a poorly characterized ATP-binding cassette system composed of the ATPase LptB and the transmembrane domains LptFG. Here, we characterize a cluster of residues in the groove region of LptB that is important for controlling LPS transport. We also provide the first functional characterization of LptFG and identify their coupling helices that interact with the LptB groove. Substitutions at conserved residues in these coupling helices compromise both the assembly and function of the LptB2FG complex. Defects in LPS transport conferred by alterations in the LptFG coupling helices can be rescued by changing a residue in LptB that is adjacent to functionally important residues in the groove region. This suppression is achieved by increasing the ATPase activity of the LptB2FG complex. Taken together, these data identify a specific binding site in LptB for the coupling helices of LptFG that is responsible for coupling of ATP hydrolysis by LptB with LptFG function to achieve LPS extraction. PMID:27795402

  2. A lower isoelectric point increases signal sequence-mediated secretion of recombinant proteins through a bacterial ABC transporter.

    PubMed

    Byun, Hyunjong; Park, Jiyeon; Kim, Sun Chang; Ahn, Jung Hoon

    2017-12-01

    Efficient protein production for industrial and academic purposes often involves engineering microorganisms to produce and secrete target proteins into the culture. Pseudomonas fluorescens has a TliDEF ATP-binding cassette transporter, a type I secretion system, which recognizes C-terminal LARD3 signal sequence of thermostable lipase TliA. Many proteins are secreted by TliDEF in vivo when recombined with LARD3, but there are still others that cannot be secreted by TliDEF even when LARD3 is attached. However, the factors that determine whether or not a recombinant protein can be secreted through TliDEF are still unknown. Here, we recombined LARD3 with several proteins and examined their secretion through TliDEF. We found that the proteins secreted via LARD3 are highly negatively charged with highly-acidic isoelectric points (pI) lower than 5.5. Attaching oligo-aspartate to lower the pI of negatively-charged recombinant proteins improved their secretion, and attaching oligo-arginine to negatively-charged proteins blocked their secretion by LARD3. In addition, negatively supercharged green fluorescent protein (GFP) showed improved secretion, whereas positively supercharged GFP did not secrete. These results disclosed that proteins' acidic pI and net negative charge are major factors that determine their secretion through TliDEF. Homology modeling for TliDEF revealed that TliD dimer forms evolutionarily-conserved positively-charged clusters in its pore and substrate entrance site, which also partially explains the pI dependence of the TliDEF-dependent secretions. In conclusion, lowering the isoelectric point improved LARD3-mediated protein secretion, both widening the range of protein targets for efficient production via secretion and signifying an important aspect of ABC transporter-mediated secretions. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. Rethinking Drug Treatment Approaches in ALS by Targeting ABC Efflux Transporters

    DTIC Science & Technology

    2014-12-01

    for ALS patients. One of the problems in finding highly efficacious treatments in ALS may derive from the so far underestimated issue of disease... efficacy the SOD1-G93A ALS mice. 15. SUBJECT TERMS Drug resistance, ALS, Therapy, Riluzole, Drug Efflux Transporters 16. SECURITY CLASSIFICATION OF...improves efficacy of ALS therapeutics Michael R. Jablonski1, Shashirekha S. Markandaiah1, Dena Jacob1, Ni J. Meng1, Ke Li2, Victoria Gennaro1, Angelo

  4. Structure of a Bacterial ABC Transporter Involved in the Import of an Acidic Polysaccharide Alginate.

    PubMed

    Maruyama, Yukie; Itoh, Takafumi; Kaneko, Ai; Nishitani, Yu; Mikami, Bunzo; Hashimoto, Wataru; Murata, Kousaku

    2015-09-01

    The acidic polysaccharide alginate represents a promising marine biomass for the microbial production of biofuels, although the molecular and structural characteristics of alginate transporters remain to be clarified. In Sphingomonas sp. A1, the ATP-binding cassette transporter AlgM1M2SS is responsible for the import of alginate across the cytoplasmic membrane. Here, we present the substrate-transport characteristics and quaternary structure of AlgM1M2SS. The addition of poly- or oligoalginate enhanced the ATPase activity of reconstituted AlgM1M2SS coupled with one of the periplasmic solute-binding proteins, AlgQ1 or AlgQ2. External fluorescence-labeled oligoalginates were specifically imported into AlgM1M2SS-containing proteoliposomes in the presence of AlgQ2, ATP, and Mg(2+). The crystal structure of AlgQ2-bound AlgM1M2SS adopts an inward-facing conformation. The interaction between AlgQ2 and AlgM1M2SS induces the formation of an alginate-binding tunnel-like structure accessible to the solvent. The translocation route inside the transmembrane domains contains charged residues suitable for the import of acidic saccharides. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Effect of β-elemene on the kinetics of intracellular transport of d-luciferin potassium salt (ABC substrate) in doxorubicin-resistant breast cancer cells and the associated molecular mechanism.

    PubMed

    Tang, Chao-Yuan; Zhu, Li-Xin; Yu, Jian-Dong; Chen, Zhi; Gu, Man-Cang; Mu, Chao-Feng; Liu, Qi; Xiong, Yang

    2018-07-30

    In order to explore the mechanism of the reversing multidrug resistance (MDR) phenotypes by β-elemene (β-ELE) in doxorubicin (DOX)-resistant breast cancer cells (MCF-7/DOX), both the functionality and quantity of the ABC transporters in MCF-7/DOX were studied. Bioluminescence imaging (BLI) was used to study the efflux of d-luciferin potassium salt, the substrate of ATP-binding cassette transporters (ABC transporters), in MCF-7/DOX cells treated by β-ELE. At the same time three major ABC transport proteins and genes-related MDR, P-glycoprotein (P-gp, ABCB1) and multidrug resistance-associated protein 1 (MRP, ABCC1) as well as breast cancer resistance protein (BCRP, ABCG2) were analyzed by q-PCR and Western blot. To investigate the efflux functionality of ABC transporters, MCF-7/DOX Fluc cell line with stably-overexpressed luciferase was established. BLI was then used to real-time monitor the efflux kinetics of d-luciferin potassium salt before and after MCF-7/DOX Fluc cells being treated with β-ELE or not. The results showed that the efflux of d-luciferin potassium salt from MCF-7/DOX Fluc was lessened when pretreated with β-ELE, which means that β-ELE may dampen the functionality of ABC transporters, thus decrease the efflux of d-fluorescein potassium or other chemotherapies which also serve as the substrates of ABC transporters. As the effect of β-ELE on the expression of ABC transporters, the results of q-PCR and Western blot showed that gene and protein expression of ABC transporters such as P-gp, MRP, and BCRP were down-regulated after the treatment of β-ELE. To verify the efficacy of β-ELE on reversing MDR, MCF-7/DOX cells were treated with the combination of DOX and β-ELE. MTT assay showed that β-ELE increased the inhibitory effect of DOX on the proliferation of MCF-7/DOX, and the IC 50 of the combination group was much lower than that of the single DOX or β-ELE treatment. In all, β-ELE may reverse MDR through the substrates of ABC transporters

  6. Attenuated mutant strain of Salmonella Typhimurium lacking the ZnuABC transporter contrasts tumor growth promoting anti-cancer immune response.

    PubMed

    Chirullo, Barbara; Ammendola, Serena; Leonardi, Leonardo; Falcini, Roberto; Petrucci, Paola; Pistoia, Claudia; Vendetti, Silvia; Battistoni, Andrea; Pasquali, Paolo

    2015-07-10

    Salmonella Typhimurium has been shown to be highly effective as antitumor agent. The aim of this study was to investigate the tumor targeting efficacy and the mechanism of action of a specific attenuated mutant strain of Salmonella Typhimurium (STM) devoid of the whole operon coding for the high-affinity zinc transporter ZnuABC, which is required for bacterial growth in environments poor in zinc and for conferring full virulence to different Gram-negative pathogens.We showed that STM is able to penetrate and replicate into tumor cells in in vitro and in vivo models. The subcutaneous administration of STM in mammary adenocarcinoma mouse model led to both reduction of tumor growth and increase in life expectancy of STM treated mice. Moreover, investigating the potential mechanism behind the favorable clinical outcomes, we provide evidence that STM stimulates a potent inflammatory response and a specific immune pattern, recruiting a large number of innate and adaptive immune cells capable to contrast the immunosuppressive environment generated by tumors.

  7. The babel of the ABCs: novel transporters involved in the regulation of sterol absorption and excretion.

    PubMed

    Ordovas, Jose M; Tai, E Shyong

    2002-01-01

    Hypercholesterolaemia is a major risk factor for coronary heart disease (CHD). Therefore, the reduction of low-density lipoprotein (LDL) cholesterol is one of the primary targets of the current recommendations to decrease CHD risk in the population. Whereas, the mechanisms involved in de novo cholesterol synthesis and its uptake by cells via the LDL receptor are well known, we still need better understanding about the mechanisms involved in intestinal cholesterol absorption and excretion. The recent discovery of ABCG5 and ABCG8 transporters will significantly improve our understanding of cholesterol trafficking and it will lead to better and new therapeutic strategies to maintain cholesterol homeostasis.

  8. ABC Transporters and Their Role in the Neoadjuvant Treatment of Esophageal Cancer

    PubMed Central

    Vaclavikova, Radka; Neoral, Cestmir; Vrba, Jiri; Aujesky, Rene; Matzenauer, Marcel; Melichar, Bohuslav

    2018-01-01

    The prognosis of esophageal cancer (EC) is poor, despite considerable effort of both experimental scientists and clinicians. The tri-modality treatment consisting of neoadjuvant chemoradiation followed by surgery has remained the gold standard over decades, unfortunately, without significant progress in recent years. Suitable prognostic factors indicating which patients will benefit from this tri-modality treatment are missing. Some patients rapidly progress on the neoadjuvant chemoradiotherapy, which is thus useless and sometimes even harmful. At the same time, other patients achieve complete remission on neoadjuvant chemoradiotherapy and subsequent surgery may increase their risk of morbidity and mortality. The prognosis of patients ranges from excellent to extremely poor. Considering these differences, the role of drug metabolizing enzymes and transporters, among other factors, in the EC response to chemotherapy may be more important compared, for example, with pancreatic cancer where all patients progress on chemotherapy regardless of the treatment or disease stage. This review surveys published literature describing the potential role of ATP-binding cassette transporters, the genetic polymorphisms, epigenetic regulations, and phenotypic changes in the prognosis and therapy of EC. The review provides knowledge base for further research of potential predictive biomarkers that will allow the stratification of patients into defined groups for optimal therapeutic outcome. PMID:29543757

  9. Convergent Loss of ABC Transporter Genes From Clostridioides difficile Genomes Is Associated With Impaired Tyrosine Uptake and p-Cresol Production.

    PubMed

    Steglich, Matthias; Hofmann, Julia D; Helmecke, Julia; Sikorski, Johannes; Spröer, Cathrin; Riedel, Thomas; Bunk, Boyke; Overmann, Jörg; Neumann-Schaal, Meina; Nübel, Ulrich

    2018-01-01

    We report the frequent, convergent loss of two genes encoding the substrate-binding protein and the ATP-binding protein of an ATP-binding cassette (ABC) transporter from the genomes of unrelated Clostridioides difficile strains. This specific genomic deletion was strongly associated with the reduced uptake of tyrosine and phenylalanine and production of derived Stickland fermentation products, including p -cresol, suggesting that the affected ABC transporter had been responsible for the import of aromatic amino acids. In contrast, the transporter gene loss did not measurably affect bacterial growth or production of enterotoxins. Phylogenomic analysis of publically available genome sequences indicated that this transporter gene deletion had occurred multiple times in diverse clonal lineages of C. difficile , with a particularly high prevalence in ribotype 027 isolates, where 48 of 195 genomes (25%) were affected. The transporter gene deletion likely was facilitated by the repetitive structure of its genomic location. While at least some of the observed transporter gene deletions are likely to have occurred during the natural life cycle of C. difficile , we also provide evidence for the emergence of this mutation during long-term laboratory cultivation of reference strain R20291.

  10. Convergent Loss of ABC Transporter Genes From Clostridioides difficile Genomes Is Associated With Impaired Tyrosine Uptake and p-Cresol Production

    PubMed Central

    Steglich, Matthias; Hofmann, Julia D.; Helmecke, Julia; Sikorski, Johannes; Spröer, Cathrin; Riedel, Thomas; Bunk, Boyke; Overmann, Jörg; Neumann-Schaal, Meina; Nübel, Ulrich

    2018-01-01

    We report the frequent, convergent loss of two genes encoding the substrate-binding protein and the ATP-binding protein of an ATP-binding cassette (ABC) transporter from the genomes of unrelated Clostridioides difficile strains. This specific genomic deletion was strongly associated with the reduced uptake of tyrosine and phenylalanine and production of derived Stickland fermentation products, including p-cresol, suggesting that the affected ABC transporter had been responsible for the import of aromatic amino acids. In contrast, the transporter gene loss did not measurably affect bacterial growth or production of enterotoxins. Phylogenomic analysis of publically available genome sequences indicated that this transporter gene deletion had occurred multiple times in diverse clonal lineages of C. difficile, with a particularly high prevalence in ribotype 027 isolates, where 48 of 195 genomes (25%) were affected. The transporter gene deletion likely was facilitated by the repetitive structure of its genomic location. While at least some of the observed transporter gene deletions are likely to have occurred during the natural life cycle of C. difficile, we also provide evidence for the emergence of this mutation during long-term laboratory cultivation of reference strain R20291. PMID:29867812

  11. N-retinylidene-phosphatidylethanolamine is the preferred retinoid substrate for the photoreceptor-specific ABC transporter ABCA4 (ABCR).

    PubMed

    Beharry, Seelochan; Zhong, Ming; Molday, Robert S

    2004-12-24

    ABCA4, a member of the family of ATP binding cassette (ABC) proteins found in rod and cone photoreceptors, has been implicated in the transport of retinoid compounds across the outer segment disk membrane following the photoactivation of rhodopsin. Mutations in the ABCA4 gene are responsible for Stargardt macular dystrophy and related retinal degenerative diseases that cause a loss in vision. To identify the retinoid substrate that interacts with ABCA4, we have isolated ABCA4 from rod outer segment disk membranes on an immunoaffinity matrix and analyzed retinoid compounds that bind to ABCA4 using high performance liquid chromatography and radiolabeling methods. When all-trans-retinal was added to ABCA4 in the presence of phosphatidylethanolamine, approximately 0.9 mol of N-retinylidene-phosphatidylethanolamine and 0.3 mol of all-trans-retinal were bound per mol of ABCA4 with an apparent K(d) of 2-5 microm. ATP and GTP released these retinoids from ABCA4, whereas ADP, GDP, and nonhydrolyzable derivatives, adenosine 5'-(beta,gamma-imido)triphosphate and guanosine 5'-(beta,gamma-imido)triphosphate, were ineffective. One mole of N-retinyl-phosphatidylethanolamine, the reduced form of N-retinylidene-phosphatidylethanolamine, bound per mol of ABCA4, whereas 0.3 mol of all-trans-retinal were bound in the absence of phosphatidylethanolamine. No binding of all-trans-retinol to ABCA4 was observed. Our results indicate that ABCA4 preferentially binds N-retinylidene-phosphatidylethanolamine with high affinity in the absence of ATP. Our studies further suggest that ATP binding and hydrolysis induces a protein conformational change that causes N-retinylidene-phosphatidylethanolamine to dissociate from ABCA4.

  12. Stubborn contaminants: influence of detergents on the purity of the multidrug ABC transporter BmrA.

    PubMed

    Wiseman, Benjamin; Kilburg, Arnaud; Chaptal, Vincent; Reyes-Mejia, Gina Catalina; Sarwan, Jonathan; Falson, Pierre; Jault, Jean-Michel

    2014-01-01

    Despite the growing interest in membrane proteins, their crystallization remains a major challenge. In the course of a crystallographic study on the multidrug ATP-binding cassette transporter BmrA, mass spectral analyses on samples purified with six selected detergents revealed unexpected protein contamination visible for the most part on overloaded SDS-PAGE. A major contamination from the outer membrane protein OmpF was detected in purifications with Foscholine 12 (FC12) but not with Lauryldimethylamine-N-oxide (LDAO) or any of the maltose-based detergents. Consequently, in the FC12 purified BmrA, OmpF easily crystallized over BmrA in a new space group, and whose structure is reported here. We therefore devised an optimized protocol to eliminate OmpF during the FC12 purification of BmrA. On the other hand, an additional band visible at ∼110 kDa was detected in all samples purified with the maltose-based detergents. It contained AcrB that crystallized over BmrA despite its trace amounts. Highly pure BmrA preparations could be obtained using either a ΔacrAB E. coli strain and n-dodecyl-β-D-maltopyranoside, or a classical E. coli strain and lauryl maltose neopentyl glycol for the overexpression and purification, respectively. Overall our results urge to incorporate a proteomics-based purity analysis into quality control checks prior to commencing crystallization assays of membrane proteins that are notoriously arduous to crystallize. Moreover, the strategies developed here to selectively eliminate obstinate contaminants should be applicable to the purification of other membrane proteins overexpressed in E. coli.

  13. Stubborn Contaminants: Influence of Detergents on the Purity of the Multidrug ABC Transporter BmrA

    PubMed Central

    Chaptal, Vincent; Reyes-Mejia, Gina Catalina; Sarwan, Jonathan; Falson, Pierre; Jault, Jean-Michel

    2014-01-01

    Despite the growing interest in membrane proteins, their crystallization remains a major challenge. In the course of a crystallographic study on the multidrug ATP-binding cassette transporter BmrA, mass spectral analyses on samples purified with six selected detergents revealed unexpected protein contamination visible for the most part on overloaded SDS-PAGE. A major contamination from the outer membrane protein OmpF was detected in purifications with Foscholine 12 (FC12) but not with Lauryldimethylamine-N-oxide (LDAO) or any of the maltose-based detergents. Consequently, in the FC12 purified BmrA, OmpF easily crystallized over BmrA in a new space group, and whose structure is reported here. We therefore devised an optimized protocol to eliminate OmpF during the FC12 purification of BmrA. On the other hand, an additional band visible at ∼110 kDa was detected in all samples purified with the maltose-based detergents. It contained AcrB that crystallized over BmrA despite its trace amounts. Highly pure BmrA preparations could be obtained using either a ΔacrAB E. coli strain and n-dodecyl-β-D-maltopyranoside, or a classical E. coli strain and lauryl maltose neopentyl glycol for the overexpression and purification, respectively. Overall our results urge to incorporate a proteomics-based purity analysis into quality control checks prior to commencing crystallization assays of membrane proteins that are notoriously arduous to crystallize. Moreover, the strategies developed here to selectively eliminate obstinate contaminants should be applicable to the purification of other membrane proteins overexpressed in E. coli. PMID:25517996

  14. Constitutive mRNA expression and protein activity levels of nine ABC efflux transporters in seven permanent cell lines derived from different tissues of rainbow trout (Oncorhynchus mykiss).

    PubMed

    Fischer, Stephan; Loncar, Jovica; Zaja, Roko; Schnell, Sabine; Schirmer, Kristin; Smital, Tvrtko; Luckenbach, Till

    2011-01-25

    Permanent fish cell lines have become common model systems for determining ecotoxicological effects of pollutants. For these cell lines little is known on the cellular active transport mechanisms that control the amount of a compound entering the cell, such as the MXR (multixenobiotic resistance) system mediated by ATP binding cassette (ABC) transport proteins. Therefore, for toxic evaluation of chemicals with those cells information on MXR is important. We here present data on constitutive mRNA expression and protein activity levels of a series of ABC efflux transporters in seven permanent cell lines derived from liver (RTL-W1; R1) and liver hepatoma (RTH-149), gill (RTgill-W1), gonad (RTG-2), gut (RTgutGC) and brain (RTbrain) of rainbow trout (Oncorhynchus mykiss). In addition to known transporters abcb1 (designated here abcb1a), abcb11, abcc1-3, abcc5 and abcg2, we quantified expression levels of a newly identified abcb1 isoform (abcb1b) and abcc4, previously unknown in trout. Quantitative real time PCR (qPCR) indicated that mRNA of the examined ABC transporters was constitutively expressed in all cell lines. Transporter mRNA expression patterns were similar in all cell lines, with expression levels of abcc transporters being 80 to over 1000 fold higher than for abcg2, abcb1a/b and abcb11 (abcc1-5>abcg2>abcb1a/b, 11). Transporter activity in the cell lines was determined by measuring uptake of transporter type specific fluorescent substrates in the presence of activity inhibitors. The combination of the ABCB1 and ABCC transporter substrate calcein-AM with inhibitors cyclosporine A, PSC833 and MK571 resulted in a concentration-dependent fluorescence increase of up to 3-fold, whereas reversin 205 caused a slight, but not concentration-dependent fluorescence increase. Accumulation of the dyes Hoechst 33342 and 2',7'-dichlorodihydrofluorescein diacetate was basically unchanged in the presence of Ko134 and taurocholate, respectively, indicating low Abcg2 and Abcb11

  15. ISS Crew Transportation and Services Requirements Document

    NASA Technical Reports Server (NTRS)

    Bayt, Robert L. (Compiler); Lueders, Kathryn L. (Compiler)

    2016-01-01

    The ISS Crew Transportation and Services Requirements Document (CCT-REQ-1130) contains all technical, safety, and crew health medical requirements that are mandatory for achieving a Crew Transportation System Certification that will allow for International Space Station delivery and return of NASA crew and limited cargo. Previously approved on TN23183.

  16. Classification of a Haemophilus influenzae ABC Transporter HI1470/71 through Its Cognate Molybdate Periplasmic Binding Protein, MolA

    SciTech Connect

    Tirado-Lee, Leidamarie; Lee, Allen; Rees, Douglas C.

    2014-10-02

    molA (HI1472) from H. influenzae encodes a periplasmic binding protein (PBP) that delivers substrate to the ABC transporter MolB{sub 2}C{sub 2} (formerly HI1470/71). The structures of MolA with molybdate and tungstate in the binding pocket were solved to 1.6 and 1.7 {angstrom} resolution, respectively. The MolA-binding protein binds molybdate and tungstate, but not other oxyanions such as sulfate and phosphate, making it the first class III molybdate-binding protein structurally solved. The {approx}100 {mu}M binding affinity for tungstate and molybdate is significantly lower than observed for the class II ModA molybdate-binding proteins that have nanomolar to low micromolar affinity for molybdate.more » The presence of two molybdate loci in H. influenzae suggests multiple transport systems for one substrate, with molABC constituting a low-affinity molybdate locus.« less

  17. Complete sequence of Enterococcus faecium pVEF3 and the detection of an omega-epsilon-zeta toxin-antitoxin module and an ABC transporter.

    PubMed

    Sletvold, H; Johnsen, P J; Hamre, I; Simonsen, G S; Sundsfjord, A; Nielsen, K M

    2008-07-01

    Glycopeptide resistant Enterococcus faecium (GREF) persists on Norwegian poultry farms despite the ban on the growth promoter avoparcin. The biological basis for long-term persistence of avoparcin resistance is not fully understood. This study presents the complete DNA sequence of the E. faecium R-plasmid pVEF3 and functional studies of some plasmid-encoded traits (a toxin-antitoxin (TA) system and an ABC transporter) that may be of importance for plasmid persistence. The pVEF3 (63.1 kbp), isolated from an E. faecium strain of poultry origin sampled in Norway in 1999, has 71 coding sequences including the vanA avoparcin/vancomycin resistance encoding gene cluster. pVEF3 encodes the TA system omega-epsilon-zeta, and plasmid stability tests and transcription analysis show that omega-epsilon-zeta is functional in Enterococcus faecalis OGIX, although with decreasing effect over time. The predicted ABC transporter was not found to confer reduced susceptibility to any of the 28 substances tested. The TA system identified in the pVEF-type plasmids may contribute to vanA plasmid persistence on Norwegian poultry farms. However, size and compositional heterogeneity among E. faecium vanA plasmids suggest that additional plasmid maintenance systems in combination with host specific factors and frequent horizontal gene transfer and rearrangement causes the observed plasmid composition and distribution patterns.

  18. Detergent Screening and Purification of the Human Liver ABC Transporters BSEP (ABCB11) and MDR3 (ABCB4) Expressed in the Yeast Pichia pastoris

    PubMed Central

    Stindt, Jan; Smits, Sander H. J.; Schmitt, Lutz

    2013-01-01

    The human liver ATP-binding cassette (ABC) transporters bile salt export pump (BSEP/ABCB11) and the multidrug resistance protein 3 (MDR3/ABCB4) fulfill the translocation of bile salts and phosphatidylcholine across the apical membrane of hepatocytes. In concert with ABCG5/G8, these two transporters are responsible for the formation of bile and mutations within these transporters can lead to severe hereditary diseases. In this study, we report the heterologous overexpression and purification of human BSEP and MDR3 as well as the expression of the corresponding C-terminal GFP-fusion proteins in the yeast Pichia pastoris. Confocal laser scanning microscopy revealed that BSEP-GFP and MDR3-GFP are localized in the plasma membrane of P. pastoris. Furthermore, we demonstrate the first purification of human BSEP and MDR3 yielding ∼1 mg and ∼6 mg per 100 g of wet cell weight, respectively. By screening over 100 detergents using a dot blot technique, we found that only zwitterionic, lipid-like detergents such as Fos-cholines or Cyclofos were able to extract both transporters in sufficient amounts for subsequent functional analysis. For MDR3, fluorescence-detection size exclusion chromatography (FSEC) screens revealed that increasing the acyl chain length of Fos-Cholines improved monodispersity. BSEP purified in n-dodecyl-β-D-maltoside or Cymal-5 after solubilization with Fos-choline 16 from P. pastoris membranes showed binding to ATP-agarose. Furthermore, detergent-solubilized and purified MDR3 showed a substrate-inducible ATPase activity upon addition of phosphatidylcholine lipids. These results form the basis for further biochemical analysis of human BSEP and MDR3 to elucidate the function of these clinically relevant ABC transporters. PMID:23593265

  19. A mutation within the extended X loop abolished substrate-induced ATPase activity of the human liver ATP-binding cassette (ABC) transporter MDR3.

    PubMed

    Kluth, Marianne; Stindt, Jan; Dröge, Carola; Linnemann, Doris; Kubitz, Ralf; Schmitt, Lutz

    2015-02-20

    The human multidrug resistance protein 3 (MDR3/ABCB4) belongs to the ubiquitous family of ATP-binding cassette (ABC) transporters and is located in the canalicular membrane of hepatocytes. There it flops the phospholipids of the phosphatidylcholine (PC) family from the inner to the outer leaflet. Here, we report the characterization of wild type MDR3 and the Q1174E mutant, which was identified previously in a patient with progressive familial intrahepatic cholestasis type 3 (PFIC-3). We expressed different variants of MDR3 in the yeast Pichia pastoris, purified the proteins via tandem affinity chromatography, and determined MDR3-specific ATPase activity in the presence or absence of phospholipids. The ATPase activity of wild type MDR3 was stimulated 2-fold by liver PC or 1,2-dioleoyl-sn-glycero-3-phosphatidylethanolamine lipids. Furthermore, the cross-linking of MDR3 with a thiol-reactive fluorophore blocked ATP hydrolysis and exhibited no PC stimulation. Similarly, phosphatidylethanolamine, phosphatidylserine, and sphingomyelin lipids did not induce an increase of wild type MDR3 ATPase activity. The phosphate analogues beryllium fluoride and aluminum fluoride led to complete inhibition of ATPase activity, whereas orthovanadate inhibited exclusively the PC-stimulated ATPase activity of MDR3. The Q1174E mutation is located in the nucleotide-binding domain in direct proximity of the leucine of the ABC signature motif and extended the X loop, which is found in ABC exporters. Our data on the Q1174E mutant demonstrated basal ATPase activity, but PC lipids were incapable of stimulating ATPase activity highlighting the role of the extended X loop in the cross-talk of the nucleotide-binding domain and the transmembrane domain. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. A Mutation within the Extended X Loop Abolished Substrate-induced ATPase Activity of the Human Liver ATP-binding Cassette (ABC) Transporter MDR3*

    PubMed Central

    Kluth, Marianne; Stindt, Jan; Dröge, Carola; Linnemann, Doris; Kubitz, Ralf; Schmitt, Lutz

    2015-01-01

    The human multidrug resistance protein 3 (MDR3/ABCB4) belongs to the ubiquitous family of ATP-binding cassette (ABC) transporters and is located in the canalicular membrane of hepatocytes. There it flops the phospholipids of the phosphatidylcholine (PC) family from the inner to the outer leaflet. Here, we report the characterization of wild type MDR3 and the Q1174E mutant, which was identified previously in a patient with progressive familial intrahepatic cholestasis type 3 (PFIC-3). We expressed different variants of MDR3 in the yeast Pichia pastoris, purified the proteins via tandem affinity chromatography, and determined MDR3-specific ATPase activity in the presence or absence of phospholipids. The ATPase activity of wild type MDR3 was stimulated 2-fold by liver PC or 1,2-dioleoyl-sn-glycero-3-phosphatidylethanolamine lipids. Furthermore, the cross-linking of MDR3 with a thiol-reactive fluorophore blocked ATP hydrolysis and exhibited no PC stimulation. Similarly, phosphatidylethanolamine, phosphatidylserine, and sphingomyelin lipids did not induce an increase of wild type MDR3 ATPase activity. The phosphate analogues beryllium fluoride and aluminum fluoride led to complete inhibition of ATPase activity, whereas orthovanadate inhibited exclusively the PC-stimulated ATPase activity of MDR3. The Q1174E mutation is located in the nucleotide-binding domain in direct proximity of the leucine of the ABC signature motif and extended the X loop, which is found in ABC exporters. Our data on the Q1174E mutant demonstrated basal ATPase activity, but PC lipids were incapable of stimulating ATPase activity highlighting the role of the extended X loop in the cross-talk of the nucleotide-binding domain and the transmembrane domain. PMID:25533467

  1. ISS Crew Transportation and Services Requirements Document

    NASA Technical Reports Server (NTRS)

    Lueders, Kathryn L. (Compiler)

    2015-01-01

    Under the guidance of processes provided by Crew Transportation Plan (CCT-PLN-1100), this document with its sister documents, Crew Transportation Technical Management Processes (CCT-PLN-1120), Crew Transportation Technical Standards and Design Evaluation Criteria (CCT-STD-1140), and Crew Transportation Operations Standards (CCT-STD-1150), and International Space Station (ISS) to Commercial Orbital Transportation Services Interface Requirements Document (SSP 50808), provides the basis for a National Aeronautics and Space Administration (NASA) certification for services to the ISS for the Commercial Provider. When NASA Crew Transportation System (CTS) certification is achieved for ISS transportation, the Commercial Provider will be eligible to provide services to and from the ISS during the services phase of the NASA Commercial Crew Program (CCP).

  2. Hydrogenase activity in the foodborne pathogen Campylobacter jejuni depends upon a novel ABC-type nickel transporter (NikZYXWV) and is SlyD-independent.

    PubMed

    Howlett, Robert M; Hughes, Bethan M; Hitchcock, Andrew; Kelly, David J

    2012-06-01

    Campylobacter jejuni is a human pathogen of worldwide significance. It is commensal in the gut of many birds and mammals, where hydrogen is a readily available electron donor. The bacterium possesses a single membrane-bound, periplasmic-facing NiFe uptake hydrogenase that depends on the acquisition of environmental nickel for activity. The periplasmic binding protein Cj1584 (NikZ) of the ATP binding cassette (ABC) transporter encoded by the cj1584c-cj1580c (nikZYXWV) operon in C. jejuni strain NCTC 11168 was found to be nickel-repressed and to bind free nickel ions with a submicromolar K(d) value, as measured by fluorescence spectroscopy. Unlike the Escherichia coli NikA protein, NikZ did not bind EDTA-chelated nickel and lacks key conserved residues implicated in metallophore interaction. A C. jejuni cj1584c null mutant strain showed an approximately 22-fold decrease in intracellular nickel content compared with the wild-type strain and a decreased rate of uptake of (63)NiCl(2). The inhibition of residual nickel uptake at higher nickel concentrations in this mutant by hexa-ammine cobalt (III) chloride or magnesium ions suggests that low-affinity uptake occurs partly through the CorA magnesium transporter. Hydrogenase activity was completely abolished in the cj1584c mutant after growth in unsupplemented media, but was fully restored after growth with 0.5 mM nickel chloride. Mutation of the putative metallochaperone gene slyD (cj0115) had no effect on either intracellular nickel accumulation or hydrogenase activity. Our data reveal a strict dependence of hydrogenase activity in C. jejuni on high-affinity nickel uptake through an ABC transporter that has distinct properties compared with the E. coli Nik system.

  3. An operon from Lactobacillus helveticus composed of a proline iminopeptidase gene (pepI) and two genes coding for putative members of the ABC transporter family of proteins.

    PubMed

    Varmanen, P; Rantanen, T; Palva, A

    1996-12-01

    A proline iminopeptidase gene (pepI) of an industrial Lactobacillus helveticus strain was cloned and found to be organized in an operon-like structure of three open reading frames (ORF1, ORF2 and ORF3). ORF1 was preceded by a typical prokaryotic promoter region, and a putative transcription terminator was found downstream of ORF3, identified as the pepI gene. Using primer-extension analyses, only one transcription start site, upstream of ORF1, was identifiable in the predicted operon. Although the size of mRNA could not be judged by Northern analysis either with ORF1-, ORF2- or pepI-specific probes, reverse transcription-PCR analyses further supported the operon structure of the three genes. ORF1, ORF2 and ORF3 had coding capacities for 50.7, 24.5 and 33.8 kDa proteins, respectively. The ORF3-encoded PepI protein showed 65% identity with the PepI proteins from Lactobacillus delbrueckii subsp. bulgaricus and Lactobacillus delbrueckii subsp. lactis. The ORF1-encoded protein had significant homology with several members of the ABC transporter family but, with two distinct putative ATP-binding sites, it would represent an unusual type among the bacterial ABC transporters. ORF2 encoded a putative integral membrane protein also characteristic of the ABC transporter family. The pepI gene was overexpressed in Escherichia coli. Purified PepI hydrolysed only di and tripeptides with proline in the first position. Optimum PepI activity was observed at pH 7.5 and 40 degrees C. A gel filtration analysis indicated that PepI is a dimer of M(r) 53,000. PepI was shown to be a metal-independent serine peptidase having thiol groups at or near the active site. Kinetic studies with proline-p-nitroanilide as substrate revealed Km and Vmax values of 0.8 mM and 350 mmol min-1 mg-1, respectively, and a very high turnover number of 135,000 s-1.

  4. Surface transport vehicles and supporting technology requirements

    NASA Technical Reports Server (NTRS)

    Matijevic, J. R.; Dias, W. C.; Levin, R. R.; Lindemann, R. A.; Smith, J. H.; Venkataraman, S. T.

    1992-01-01

    Requirements have been identified for surface transport vehicles which allow remote scientific exploration on the moon, as well as lunar resource recovery and emplacement of a permanent base on the lunar surface. Attention is given to the results of a design study which developed configurational concepts for lunar surface transport vehicles and inferred technology-development requirements, with a view to a phased program of implementation. Distinct benefits are noted for the design of simple vehicle platforms with high commonality, in order to reduce logistical-support requirements and maximize functional flexibility. Two generic vehicle classed are defined.

  5. Interaction of BDE-47 and its Hydroxylated Metabolite 6-OH-BDE-47 with the Human ABC Efflux Transporters P-gp and BCRP: Considerations for Human Exposure and Risk Assessment

    EPA Science Inventory

    ATP binding cassette (ABC) transporters, including P-glycoprotein (P-gp; also known as MDR1, ABCB1) and breast cancer resistance protein (BCRP; also known as ABCG2), are membrane-bound proteins that mediate the cellular efflux of xenobiotics as an important defense against chemic...

  6. Increased expression of the yeast multidrug resistance ABC transporter Pdr18 leads to increased ethanol tolerance and ethanol production in high gravity alcoholic fermentation

    PubMed Central

    2012-01-01

    Background The understanding of the molecular basis of yeast tolerance to ethanol may guide the design of rational strategies to increase process performance in industrial alcoholic fermentations. A set of 21 genes encoding multidrug transporters from the ATP-Binding Cassette (ABC) Superfamily and Major Facilitator Superfamily (MFS) in S. cerevisiae were scrutinized for a role in ethanol stress resistance. Results A yeast multidrug resistance ABC transporter encoded by the PDR18 gene, proposed to play a role in the incorporation of ergosterol in the yeast plasma membrane, was found to confer resistance to growth inhibitory concentrations of ethanol. PDR18 expression was seen to contribute to decreased 3 H-ethanol intracellular concentrations and decreased plasma membrane permeabilization of yeast cells challenged with inhibitory ethanol concentrations. Given the increased tolerance to ethanol of cells expressing PDR18, the final concentration of ethanol produced during high gravity alcoholic fermentation by yeast cells devoid of PDR18 was lower than the final ethanol concentration produced by the corresponding parental strain. Moreover, an engineered yeast strain in which the PDR18 promoter was replaced in the genome by the stronger PDR5 promoter, leading to increased PDR18 mRNA levels during alcoholic fermentation, was able to attain a 6 % higher ethanol concentration and a 17 % higher ethanol production yield than the parental strain. The improved fermentative performance of yeast cells over-expressing PDR18 was found to correlate with their increased ethanol tolerance and ability to restrain plasma membrane permeabilization induced throughout high gravity fermentation. Conclusions PDR18 gene over-expression increases yeast ethanol tolerance and fermentation performance leading to the production of highly inhibitory concentrations of ethanol. PDR18 overexpression in industrial yeast strains appears to be a promising approach to improve alcoholic

  7. Down-regulation of a novel ABC transporter gene (Pxwhite) is associated with Cry1Ac resistance in the diamondback moth, Plutella xylostella (L.).

    PubMed

    Guo, Zhaojiang; Kang, Shi; Zhu, Xun; Xia, Jixing; Wu, Qingjun; Wang, Shaoli; Xie, Wen; Zhang, Youjun

    2015-04-01

    Biopesticides or transgenic crops based on Cry toxins from the soil bacterium Bacillus thuringiensis (Bt) effectively control agricultural insect pests. The sustainable use of Bt biopesticides and Bt crops is threatened, however, by the development of Cry resistance in the target pests. The diamondback moth, Plutella xylostella (L.), is the first pest that developed resistance to a Bt biopesticide in the field, and a recent study has shown that the resistance of P. xylostella to Cry1Ac is caused by a mutation in an ATP-binding cassette (ABC) transporter gene (ABCC2). In this study, we report that down-regulation of a novel ABC transporter gene from ABCG subfamily (Pxwhite) is associated with Cry1Ac resistance in P. xylostella. The full-length cDNA sequence of Pxwhite was cloned and analyzed. Spatial-temporal expression detection revealed that Pxwhite was expressed in all tissues and developmental stages, and highest expressed in Malpighian tubule tissue and in egg stage. Sequence variation analysis of Pxwhite indicated the absence of constant non-synonymous mutations between susceptible and resistant strains, whereas midgut transcript analysis showed that Pxwhite was remarkably reduced in all resistant strains and further reduced when larvae of the moderately resistant SZ-R strain were subjected to selection with Cry1Ac toxin. Furthermore, RNA interference (RNAi)-mediated suppression of Pxwhite gene expression significantly reduced larval susceptibility to Cry1Ac toxin, and genetic linkage analysis confirmed that down-regulation of Pxwhite gene is tightly linked to Cry1Ac resistance in P. xylostella. To our knowledge, this is the first report indicating that Pxwhite gene is involved in Cry1Ac resistance in P. xylostella. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. LABCG2, a New ABC Transporter Implicated in Phosphatidylserine Exposure, Is Involved in the Infectivity and Pathogenicity of Leishmania

    PubMed Central

    González-Rey, Elena; Delgado, Mario; Castanys, Santiago; Pérez-Victoria, José M.; Gamarro, Francisco

    2013-01-01

    Leishmaniasis is a neglected disease produced by the intracellular protozoan parasite Leishmania. In the present study, we show that LABCG2, a new ATP-binding cassette half-transporter (ABCG subfamily) from Leishmania, is involved in parasite virulence. Down-regulation of LABCG2 function upon expression of an inactive mutant version of this half-transporter (LABCG2K/M) is shown to reduce the translocation of short-chain analogues of phosphatidylserine (PS). This dominant-negative phenotype is specific for the headgroup of the phospholipid, as the movement of phospholipid analogues of phosphatidylcholine, phosphatidylethanolamine or sphingomyelin is not affected. In addition, promastigotes expressing LABCG2K/M expose less endogenous PS in the stationary phase than control parasites. Transient exposure of PS at the outer leaflet of the plasma membrane is known to be one of the mechanisms used by Leishmania to infect macrophages and to silence their immune response. Stationary phase/metacyclic promastigotes expressing LABCG2K/M are less infective for macrophages and show decreased pathogenesis in a mouse model of cutaneous leishmaniasis. Thus, mice infected with parasites expressing LABCG2K/M did not develop any lesion and showed significantly lower inflammation and parasite burden than mice infected with control parasites. Our results indicate that LABCG2 function is required for the externalization of PS in Leishmania promastigotes, a process that is involved in the virulence of the parasite. PMID:23638200

  9. 75 FR 49549 - ABC & D Recycling, Inc.-Lease and Operation Exemption-a Line of Railroad in Ware, MA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-13

    ... DEPARTMENT OF TRANSPORTATION Surface Transportation Board [Docket No. FD 35397] ABC & D Recycling, Inc.--Lease and Operation Exemption--a Line of Railroad in Ware, MA ABC & D Recycling, Inc. (ABC & D..., ABC & D Recycling, Inc.--Lease and Operation Exemption--a Line of Railroad in Ware, Massachusetts (STB...

  10. The naphthoquinones, vitamin K3 and its structural analog plumbagin, are substrates of the multidrug resistance-linked ABC drug transporter ABCG2

    PubMed Central

    Shukla, Suneet; Wu, Chung-Pu; Nandigama, Krishnamachary; Ambudkar, Suresh V.

    2008-01-01

    Vitamin K3 (Menadione; 2-methyl-1,4-naphthoquinone) is a structural precursor of vitamins K1 and K2 which are essential for blood clotting. The naturally occurring structural analog of this vitamin, plumbagin (5-hydroxy-menadione), is known to modulate cellular proliferation, apoptosis, carcinogenesis, and radioresistance. We, here, report that both vitamin K3 and plumbagin are substrates of the multidrug resistance-linked ATP binding cassette (ABC) drug transporter, ABCG2. Vitamin K3 and plumbagin specifically inhibited the ABCG2-mediated efflux of mitoxantrone, but did not have any effect on the ABCB1-mediated efflux of rhodamine 123. This inhibition of ABCG2 function was due to their interaction at the substrate-binding site(s). They inhibited the binding of [125I]-Iodoarylazidoprazosin (IAAP), a substrate of ABCG2, to this transporter in a concentration-dependent manner with IC50 values of 7.3 and 22.6 μM, respectively, but had no effect on the binding of this photoaffinity analog to ABCB1. Both compounds stimulated ABCG2-mediated ATP hydrolysis and also inhibited the mitoxantrone-stimulated ATPase activity of this transporter, but did not have any significant effect on the ATPase activity of ABCB1. In a cytotoxicity assay, ABCG2-expressing HEK cells were 2.8- and 2.3-fold resistant to plumbagin and vitamin K3, respectively, compared to the control cells, suggesting that they are substrates of this transporter. Collectively, these data demonstrate for the first time that vitamin K3 is a substrate of the ABCG2 transporter. Thus, ABCG2 may have a role in the regulation of vitamin K3 levels in the body. In addition, vitamin K3 and its structural derivative, plumbagin, could potentially be used to modulate ABCG2 function. PMID:18065489

  11. Molecular identification of an ABC transporter complex for manganese: analysis of a cyanobacterial mutant strain impaired in the photosynthetic oxygen evolution process.

    PubMed Central

    Bartsevich, V V; Pakrasi, H B

    1995-01-01

    During photosynthesis, the photosystem II (PSII) pigment-protein complex catalyzes oxygen evolution, a reaction in which a four-manganese ensemble plays a crucial role. Using a newly developed selection scheme, we have isolated BP13, a random photosynthesis-deficient mutant strain of the cyanobacterium, Synechocystis 6803. This mutant grew slowly under photoautotrophic conditions, and had a low oxygen evolution activity. Biochemical analysis revealed that the lesion in this mutant strain had specifically affected the Mn ensemble in PSII. Interestingly, incubation of BP13 cells with micromolar levels of added Mn induced rapid recovery of oxygen evolution activity. The mutant could be complemented with a fragment of wild-type chromosomal DNA containing three closely linked genes, mntA, mntB and mntC. These gene products showed significant sequence similarities with polypeptide components of bacterial permeases that are members of the 'ABC (ATP binding cassette) superfamily' of transporter proteins. We determined that in the BP13 strain, a single nucleotide change had resulted in the replacement of an alanine by an aspartic acid residue in MntA, a soluble protein containing ATP binding motifs. These results suggest that the mntCAB gene cluster encodes polypeptide components of a Mn transporter, the first such protein complex identified in any organism. PMID:7743991

  12. Whole genome re-sequencing identifies a mutation in an ABC transporter (mdr2) in a Plasmodium chabaudi clone with altered susceptibility to antifolate drugs☆

    PubMed Central

    Martinelli, Axel; Henriques, Gisela; Cravo, Pedro; Hunt, Paul

    2011-01-01

    In malaria parasites, mutations in two genes of folate biosynthesis encoding dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps) modify responses to antifolate therapies which target these enzymes. However, the involvement of other genes which modify the availability of exogenous folate, for example, has been proposed. Here, we used short-read whole-genome re-sequencing to determine the mutations in a clone of the rodent malaria parasite, Plasmodium chabaudi, which has altered susceptibility to both sulphadoxine and pyrimethamine. This clone bears a previously identified S106N mutation in dhfr and no mutation in dhps. Instead, three additional point mutations in genes on chromosomes 2, 13 and 14 were identified. The mutated gene on chromosome 13 (mdr2 K392Q) encodes an ABC transporter. Because Quantitative Trait Locus analysis previously indicated an association of genetic markers on chromosome 13 with responses to individual and combined antifolates, MDR2 is proposed to modulate antifolate responses, possibly mediated by the transport of folate intermediates. PMID:20858498

  13. Rail Transportation Requirements for Coal Movement in 1985

    DOT National Transportation Integrated Search

    1978-12-01

    This study of transportation requirements for coal movements through 1985 is one of the series conducted for the U.S. Department of Transportation to identify and quantify future transportation requirements for energy materials. This report presents ...

  14. Water Transportation Requirements for Coal Movement in 1985

    DOT National Transportation Integrated Search

    1978-12-01

    This study of transportation requirements for coal movements through 1985 is one of a series conducted for the U.S. Department of Transportation to identify and quantify future transportation requirements for energy materials. The primary objectives ...

  15. Characterization of a lactose-responsive promoter of ATP-binding cassette (ABC) transporter gene from Lactobacillus acidophilus 05-172.

    PubMed

    Zeng, Zhu; Zuo, Fanglei; Yu, Rui; Zhang, Bo; Ma, Huiqin; Chen, Shangwu

    2017-09-01

    A novel lactose-responsive promoter of the ATP-binding cassette (ABC) transporter gene Lba1680 of Lactobacillus acidophilus strain 05-172 isolated from a traditionally fermented dairy product koumiss was characterized. In L. acidophilus 05-172, expression of Lba1680 was induced by lactose, with lactose-induced transcription of Lba1680 being 6.1-fold higher than that induced by glucose. This is in contrast to L. acidophilus NCFM, a strain isolated from human feces, in which expression of Lba1680 and Lba1679 is induced by glucose. Both gene expression and enzyme activity assays in L. paracasei transformed with a vector containing the inducible Lba1680 promoter (PLba1680) of strain 05-172 and a heme-dependent catalase gene as reporter confirmed that PLba1680 is specifically induced by lactose. Its regulatory expression could not be repressed by glucose, and was independent of cAMP receptor protein. This lactose-responsive promoter might be used in the expression of functional genes in L. paracasei incorporated into a lactose-rich environment, such as dairy products. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. The ABC model of recombination reinterpreted: Impact on understanding carrier transport and efficiency droop in InGaN/GaN light emitting diodes

    NASA Astrophysics Data System (ADS)

    Hopkins, M. A.; Allsopp, D. W. E.; Kappers, M. J.; Oliver, R. A.; Humphreys, C. J.

    2017-12-01

    The efficiency of light emitting diodes (LEDs) remains a topic of great contemporary interest due to their potential to reduce the amount of energy consumed in lighting. The current consensus is that electrons and holes distribute themselves through the emissive region by a drift-diffusion process which results in a highly non-uniform distribution of the light emission and can reduce efficiency. In this paper, the measured variations in the external quantum efficiency of a range of InGaN/GaN LEDs with different numbers of quantum wells (QWs) are shown to compare closely with the predictions of a revised ABC model, in which it is assumed that the electrically injected electrons and holes are uniformly distributed through the multi-quantum well (MQW) region, or nearly so, and hence carrier recombination occurs equally in all the quantum wells. The implications of the reported results are that drift-diffusion plays a far lesser role in cross-well carrier transport than previously thought; that the dominant cause of efficiency droop is intrinsic to the quantum wells and that reductions in the density of non-radiative recombination centers in the MQW would enable the use of more QWs and thereby reduce Auger losses by spreading carriers more evenly across a wider emissive region.

  17. Induction of hepatic ABC transporter expression is part of the PPARalpha-mediated fasting response in the mouse.

    PubMed

    Kok, Tineke; Wolters, Henk; Bloks, Vincent W; Havinga, Rick; Jansen, Peter L M; Staels, Bart; Kuipers, Folkert

    2003-01-01

    Fatty acids are natural ligands of the peroxisome proliferator-activated receptor alpha (PPARalpha). Synthetic ligands of this nuclear receptor, i.e., fibrates, induce the hepatic expression of the multidrug resistance 2 gene (Mdr2), encoding the canalicular phospholipid translocator, and affect hepatobiliary lipid transport. We tested whether fasting-associated fatty acid release from adipose tissues alters hepatic transporter expression and bile formation in a PPARalpha-dependent manner. A 24-hour fasting/48-hour refeeding schedule was used in wild-type and Pparalpha((-/-)) mice. Expression of genes involved in the control of bile formation was determined and related to secretion rates of biliary components. Expression of Pparalpha, farnesoid X receptor, and liver X receptor alpha genes encoding nuclear receptors that control hepatic bile salt and sterol metabolism was induced on fasting in wild-type mice only. The expression of Mdr2 was 5-fold increased in fasted wild-type mice and increased only marginally in Pparalpha((-/-)) mice, and it normalized on refeeding. Mdr2 protein levels and maximal biliary phospholipid secretion rates were clearly increased in fasted wild-type mice. Hepatic expression of the liver X receptor target genes ATP binding cassette transporter a1 (Abca1), Abcg5, and Abcg8, implicated in hepatobiliary cholesterol transport, was induced in fasted wild-type mice only. However, the maximal biliary cholesterol secretion rate was reduced by approximately 50%. Induction of Mdr2 expression and function is part of the PPARalpha-mediated fasting response in mice. Fasting also induces expression of the putative hepatobiliary cholesterol transport genes Abca1, Abcg5, and Abcg8, but, nonetheless, maximal biliary cholesterol excretion is decreased after fasting.

  18. The ABC and AUSSAT.

    ERIC Educational Resources Information Center

    McGarritty, Ian

    1985-01-01

    Discusses the Australian Broadcasting Corporation's (ABC) utilization of the AUSSAT telecommunications satellite to extend its television and radio transmission range to reach remote Australian audiences; the satellite's program gathering and interchange capabilities; and ABC's generation of other benefits to offset cost of satellite services.…

  19. Multidrug Resistance Protein 1 (MRP1, ABCC1), a “Multitasking” ATP-binding Cassette (ABC) Transporter*

    PubMed Central

    Cole, Susan P. C.

    2014-01-01

    The multidrug resistance protein 1 (MRP1) encoded by ABCC1 was originally discovered as a cause of multidrug resistance in tumor cells. However, it is now clear that MRP1 serves a broader role than simply mediating the ATP-dependent efflux of drugs from cells. The antioxidant GSH and the pro-inflammatory cysteinyl leukotriene C4 have been identified as key physiological organic anions effluxed by MRP1, and an ever growing body of evidence indicates that additional lipid-derived mediators are also substrates of this transporter. As such, MRP1 is a multitasking transporter that likely influences the etiology and progression of a host of human diseases. PMID:25281745

  20. Rail Transportation Requirements for Coal Movement in 1980

    DOT National Transportation Integrated Search

    1976-12-01

    This rail-oriented coal transportation study is one of a series conducted by the Department of Transportation to identify and quantify transportation requirements for energy materials. Information provided by these studies will be used by government ...

  1. Metabolic Interactions of Purine Derivatives with Human ABC Transporter ABCG2: Genetic Testing to Assess Gout Risk.

    PubMed

    Ishikawa, Toshihisa; Aw, Wanping; Kaneko, Kiyoko

    2013-11-04

    In mammals, excess purine nucleosides are removed from the body by breakdown in the liver and excretion from the kidneys. Uric acid is the end product of purine metabolism in humans. Two-thirds of uric acid in the human body is normally excreted through the kidney, whereas one-third undergoes uricolysis (decomposition of uric acid) in the gut. Elevated serum uric acid levels result in gout and could be a risk factor for cardiovascular disease and diabetes. Recent studies have shown that human ATP-binding cassette transporter ABCG2 plays a role of renal excretion of uric acid. Two non-synonymous single nucleotide polymorphisms (SNPs), i.e., 421C>A (major) and 376C>T (minor), in the ABCG2 gene result in impaired transport activity, owing to ubiquitination-mediated proteosomal degradation and truncation of ABCG2, respectively. These genetic polymorphisms are associated with hyperuricemia and gout. Allele frequencies of those SNPs are significantly higher in Asian populations than they are in African and Caucasian populations. A rapid and isothermal genotyping method has been developed to detect the SNP 421C>A, where one drop of peripheral blood is sufficient for the detection. Development of simple genotyping methods would serve to improve prevention and early therapeutic intervention for high-risk individuals in personalized healthcare.

  2. 49 CFR 173.448 - General transportation requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false General transportation requirements. 173.448 Section 173.448 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SHIPPERS...

  3. 49 CFR 173.448 - General transportation requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false General transportation requirements. 173.448 Section 173.448 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SHIPPERS...

  4. 49 CFR 173.448 - General transportation requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false General transportation requirements. 173.448 Section 173.448 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SHIPPERS...

  5. Therapeutic and biological importance of getting nucleotides out of cells: a case for the ABC transporters, MRP4 and 5.

    PubMed

    Adachi, Masashi; Reid, Glen; Schuetz, John D

    2002-11-18

    The energy dependent transport of drugs contributes to cellular resistance and is undoubtedly a prime suspect in chemotherapeutic failure of a variety of disease processes. Early studies focused on a single gene, the multidrug resistance gene, MDR1, as a main contributor to chemotherapeutic failure. However, the multifaceted nature of cellular resistance lead to the discovery of the MRP gene. This pivotal finding and the concurrent rapid development of gene databases lead to the expansion of the MRP gene family. The purpose of this review is to discuss two of the recently described MRP family members that were orphans until their role in drug resistance was discovered. This review will provide an overview of the current state of our understanding of MRP4 and 5.

  6. A Putative ABC Transporter Permease Is Necessary for Resistance to Acidified Nitrite and EDTA in Pseudomonas aeruginosa under Aerobic and Anaerobic Planktonic and Biofilm Conditions

    PubMed Central

    McDaniel, Cameron; Su, Shengchang; Panmanee, Warunya; Lau, Gee W.; Browne, Tristan; Cox, Kevin; Paul, Andrew T.; Ko, Seung-Hyun B.; Mortensen, Joel E.; Lam, Joseph S.; Muruve, Daniel A.; Hassett, Daniel J.

    2016-01-01

    Pseudomonas aeruginosa (PA) is an important airway pathogen of cystic fibrosis and chronic obstructive disease patients. Multiply drug resistant PA is becoming increasing prevalent and new strategies are needed to combat such insidious organisms. We have previously shown that a mucoid, mucA22 mutant PA is exquisitely sensitive to acidified nitrite (A-NO2−, pH 6.5) at concentrations that are well tolerated in humans. Here, we used a transposon mutagenesis approach to identify PA mutants that are hypersensitive to A-NO2−. Among greater than 10,000 mutants screened, we focused on PA4455, in which the transposon was found to disrupt the production of a putative cytoplasmic membrane-spanning ABC transporter permease. The PA4455 mutant was not only highly sensitive to A-NO2−, but also the membrane perturbing agent, EDTA and the antibiotics doxycycline, tigecycline, colistin, and chloramphenicol, respectively. Treatment of bacteria with A-NO2− plus EDTA, however, had the most dramatic and synergistic effect, with virtually all bacteria killed by 10 mM A-NO2−, and EDTA (1 mM, aerobic, anaerobic). Most importantly, the PA4455 mutant was also sensitive to A-NO2− in biofilms. A-NO2− sensitivity and an anaerobic growth defect was also noted in two mutants (rmlC and wbpM) that are defective in B-band LPS synthesis, potentially indicating a membrane defect in the PA4455 mutant. Finally, this study describes a gene, PA4455, that when mutated, allows for dramatic sensitivity to the potential therapeutic agent, A-NO2− as well as EDTA. Furthermore, the synergy between the two compounds could offer future benefits against antibiotic resistant PA strains. PMID:27064218

  7. ABC transporters and the proteasome complex are implicated in susceptibility to Stevens-Johnson syndrome and toxic epidermal necrolysis across multiple drugs.

    PubMed

    Nicoletti, Paola; Bansal, Mukesh; Lefebvre, Celine; Guarnieri, Paolo; Shen, Yufeng; Pe'er, Itsik; Califano, Andrea; Floratos, Aris

    2015-01-01

    Stevens-Johnson syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) represent rare but serious adverse drug reactions (ADRs). Both are characterized by distinctive blistering lesions and significant mortality rates. While there is evidence for strong drug-specific genetic predisposition related to HLA alleles, recent genome wide association studies (GWAS) on European and Asian populations have failed to identify genetic susceptibility alleles that are common across multiple drugs. We hypothesize that this is a consequence of the low to moderate effect size of individual genetic risk factors. To test this hypothesis we developed Pointer, a new algorithm that assesses the aggregate effect of multiple low risk variants on a pathway using a gene set enrichment approach. A key advantage of our method is the capability to associate SNPs with genes by exploiting physical proximity as well as by using expression quantitative trait loci (eQTLs) that capture information about both cis- and trans-acting regulatory effects. We control for known bias-inducing aspects of enrichment based analyses, such as: 1) gene length, 2) gene set size, 3) presence of biologically related genes within the same linkage disequilibrium (LD) region, and, 4) genes shared among multiple gene sets. We applied this approach to publicly available SJS/TEN genome-wide genotype data and identified the ABC transporter and Proteasome pathways as potentially implicated in the genetic susceptibility of non-drug-specific SJS/TEN. We demonstrated that the innovative SNP-to-gene mapping phase of the method was essential in detecting the significant enrichment for those pathways. Analysis of an independent gene expression dataset provides supportive functional evidence for the involvement of Proteasome pathways in SJS/TEN cutaneous lesions. These results suggest that Pointer provides a useful framework for the integrative analysis of pharmacogenetic GWAS data, by increasing the power to detect aggregate effects

  8. Forkhead-associated (FHA) Domain Containing ABC Transporter Rv1747 Is Positively Regulated by Ser/Thr Phosphorylation in Mycobacterium tuberculosis*

    PubMed Central

    Spivey, Vicky L.; Molle, Virginie; Whalan, Rachael H.; Rodgers, Angela; Leiba, Jade; Stach, Lasse; Walker, K. Barry; Smerdon, Stephen J.; Buxton, Roger S.

    2011-01-01

    One major signaling method employed by Mycobacterium tuberculosis, the causative agent of tuberculosis, is through reversible phosphorylation of proteins mediated by protein kinases and phosphatases. This study concerns one of these enzymes, the serine/threonine protein kinase PknF, that is encoded in an operon with Rv1747, an ABC transporter that is necessary for growth of M. tuberculosis in vivo and contains two forkhead-associated (FHA) domains. FHA domains are phosphopeptide recognition motifs that specifically recognize phosphothreonine-containing epitopes. Experiments to determine how PknF regulates the function of Rv1747 demonstrated that phosphorylation occurs on two specific threonine residues, Thr-150 and Thr-208. To determine the in vivo consequences of phosphorylation, infection experiments were performed in bone marrow-derived macrophages and in mice using threonine-to-alanine mutants of Rv1747 that prevent specific phosphorylation and revealed that phosphorylation positively modulates Rv1747 function in vivo. The role of the FHA domains in this regulation was further demonstrated by isothermal titration calorimetry, using peptides containing both phosphothreonine residues. FHA-1 domain mutation resulted in attenuation in macrophages highlighting the critical role of this domain in Rv1747 function. A mutant deleted for pknF did not, however, have a growth phenotype in an infection, suggesting that other kinases can fulfill its role when it is absent. This study provides the first information on the molecular mechanism(s) regulating Rv1747 through PknF-dependent phosphorylation but also indicates that phosphorylation activates Rv1747, which may have important consequences in regulating growth of M. tuberculosis. PMID:21622570

  9. Substrate Binding Protein DppA1 of ABC Transporter DppBCDF Increases Biofilm Formation in Pseudomonas aeruginosa by Inhibiting Pf5 Prophage Lysis

    PubMed Central

    Lee, Yunho; Song, Sooyeon; Sheng, Lili; Zhu, Lei; Kim, Jun-Seob; Wood, Thomas K.

    2018-01-01

    Filamentous phage impact biofilm development, stress tolerance, virulence, biofilm dispersal, and colony variants. Previously, we identified 137 Pseudomonas aeruginosa PA14 mutants with more than threefold enhanced and 88 mutants with more than 10-fold reduced biofilm formation by screening 5850 transposon mutants (PLoS Pathogens 5: e1000483, 2009). Here, we characterized the function of one of these 225 mutations, dppA1 (PA14_58350), in regard to biofilm formation. DppA1 is a substrate-binding protein (SBP) involved in peptide utilization via the DppBCDF ABC transporter system. We show that compared to the wild-type strain, inactivating dppA1 led to 68-fold less biofilm formation in a static model and abolished biofilm formation in flow cells. Moreover, the dppA1 mutant had a delay in swarming and produced 20-fold less small-colony variants, and both biofilm formation and swarming were complemented by producing DppA1. A whole-transcriptome analysis showed that only 10 bacteriophage Pf5 genes were significantly induced in the biofilm cells of the dppA1 mutant compared to the wild-type strain, and inactivation of dppA1 resulted in a 600-fold increase in Pf5 excision and a million-fold increase in phage production. As expected, inactivating Pf5 genes PA0720 and PA0723 increased biofilm formation substantially. Inactivation of DppA1 also reduced growth (due to cell lysis). Hence, DppA1 increases biofilm formation by repressing Pf5 prophage. PMID:29416528

  10. The Novel Helicobacter pylori CznABC Metal Efflux Pump Is Required for Cadmium, Zinc, and Nickel Resistance, Urease Modulation, and Gastric Colonization

    PubMed Central

    Stähler, Frank Nils; Odenbreit, Stefan; Haas, Rainer; Wilrich, Julia; Vliet, Arnoud H. M. Van; Kusters, Johannes G.; Kist, Manfred; Bereswill, Stefan

    2006-01-01

    Maintaining metal homeostasis is crucial for the adaptation of Helicobacter pylori to the gastric environment. Iron, copper, and nickel homeostasis has recently been demonstrated to be required for the establishment of H. pylori infection in animal models. Here we demonstrate that the HP0969-0971 gene cluster encoding the Czc-type metal export pump homologs HP0969, HP0970, and the H. pylori-specific protein HP0971 forms part of a novel H. pylori metal resistance determinant, which is required for gastric colonization and for the modulation of urease activity. Insertional mutagenesis of the HP0971, HP0970, or HP0969 genes in H. pylori reference strain 26695 resulted in increased sensitivity to cadmium, zinc, and nickel (czn), suggesting that the encoded proteins constitute a metal-specific export pump. Accordingly, the genes were designated cznC (HP0971), cznB (HP0970), and cznA (HP0969). The CznC and CznA proteins play a predominant role in nickel homeostasis, since only the cznC and cznA mutants but not the cznB mutant displayed an 8- to 10-fold increase in urease activity. Nickel-specific affinity chromatography demonstrated that recombinant versions of CznC and CznB can bind to nickel and that the purified CznB protein interacted with cadmium and zinc, since both metals competitively inhibited nickel binding. Finally, single cznA, cznB, and cznC mutants did not colonize the stomach in a Mongolian gerbil-based animal model. This demonstrates that the metal export functions of H. pylori cznABC are essential for gastric colonization and underlines the extraordinary importance of metal ion homeostasis for the survival of H. pylori in the gastric environment. PMID:16790756

  11. Impaired phloem loading in zmsweet13a,b,c sucrose transporter triple knock-out mutants in Zea mays.

    PubMed

    Bezrutczyk, Margaret; Hartwig, Thomas; Horschman, Marc; Char, Si Nian; Yang, Jinliang; Yang, Bing; Frommer, Wolf B; Sosso, Davide

    2018-04-01

    Crop yield depends on efficient allocation of sucrose from leaves to seeds. In Arabidopsis, phloem loading is mediated by a combination of SWEET sucrose effluxers and subsequent uptake by SUT1/SUC2 sucrose/H + symporters. ZmSUT1 is essential for carbon allocation in maize, but the relative contribution to apoplasmic phloem loading and retrieval of sucrose leaking from the translocation path is not known. Here we analysed the contribution of SWEETs to phloem loading in maize. We identified three leaf-expressed SWEET sucrose transporters as key components of apoplasmic phloem loading in Zea mays L. ZmSWEET13 paralogues (a, b, c) are among the most highly expressed genes in the leaf vasculature. Genome-edited triple knock-out mutants were severely stunted. Photosynthesis of mutants was impaired and leaves accumulated high levels of soluble sugars and starch. RNA-seq revealed profound transcriptional deregulation of genes associated with photosynthesis and carbohydrate metabolism. Genome-wide association study (GWAS) analyses may indicate that variability in ZmSWEET13s correlates with agronomical traits, especifically flowering time and leaf angle. This work provides support for cooperation of three ZmSWEET13s with ZmSUT1 in phloem loading in Z. mays. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

  12. ¹⁸FDG a PET tumor diagnostic tracer is not a substrate of the ABC transporter P-glycoprotein.

    PubMed

    Krasznai, Zoárd T; Trencsényi, György; Krasznai, Zoltán; Mikecz, Pál; Nizsalóczki, Enikő; Szalóki, Gábor; Szabó, Judit P; Balkay, László; Márián, Teréz; Goda, Katalin

    2014-11-20

    2-[(18)F]fluoro-2-deoxy-d-glucose ((18)FDG) is a tumor diagnostic radiotracer of great importance in both diagnosing primary and metastatic tumors and in monitoring the efficacy of the treatment. P-glycoprotein (Pgp) is an active transporter that is often expressed in various malignancies either intrinsically or appears later upon disease progression or in response to chemotherapy. Several authors reported that the accumulation of (18)FDG in P-glycoprotein (Pgp) expressing cancer cells (Pgp(+)) and tumors is different from the accumulation of the tracer in Pgp nonexpressing (Pgp(-)) ones, therefore we investigated whether (18)FDG is a substrate or modulator of Pgp pump. Rhodamine 123 (R123) accumulation experiments and ATPase assay were used to detect whether (18)FDG is substrate for Pgp. The accumulation and efflux kinetics of (18)FDG were examined in two different human gynecologic (A2780/A2780AD and KB-3-1/KB-V1) and a mouse fibroblast (3T3 and 3T3MDR1) Pgp(+) and Pgp(-) cancer cell line pairs both in cell suspension and monolayer cultures. We found that (18)FDG and its derivatives did not affect either the R123 accumulation in Pgp(+) cells or the basal and the substrate stimulated ATPase activity of Pgp supporting that they are not substrates or modulators of the pump. Measuring the accumulation and efflux kinetics of (18)FDG in different Pgp(+) and Pgp(-) cell line pairs, we have found that the Pgp(+) cells exhibited significantly higher (p⩽0.01) (18)FDG accumulation and slightly faster (18)FDG efflux kinetics compared to their Pgp(-) counterparts. The above data support the idea that expression of Pgp may increase the energy demand of cells resulting in higher (18)FDG accumulation and faster efflux. We concluded that (18)FDG and its metabolites are not substrates of Pgp. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Glaucarubinone sensitizes KB cells to paclitaxel by inhibiting ABC transporters via ROS-dependent and p53-mediated activation of apoptotic signaling pathways

    PubMed Central

    Karthikeyan, Subburayan; Hoti, Sugeerappa Laxmanappa; Nazeer, Yasin; Hegde, Harsha Vasudev

    2016-01-01

    Multidrug resistance (MDR) is considered to be the major contributor to failure of chemotherapy in oral squamous cell carcinoma (SCC). This study was aimed to explore the effects and mechanisms of glaucarubinone (GLU), one of the major quassinoids from Simarouba glauca DC, in potentiating cytotoxicity of paclitaxel (PTX), an anticancer drug in KB cells. Our data showed that the administration of GLU pre-treatment significantly enhanced PTX anti-proliferative effect in ABCB1 over-expressing KB cells. The Rh 123 drug efflux studies revealed that there was a significant transport function inhibition by GLU-PTX treatment. Interestingly, it was also found that this enhanced anticancer efficacy of GLU was associated with PTX-induced cell arrest in the G2/M phase of cell cycle. Further, the combined treatment of GLU-PTX had significant decrease in the expression levels of P-gp, MRPs, and BCRP in resistant KB cells at both mRNA and protein levels. Furthermore, the combination treatments showed significant reactive oxygen species (ROS) production, chromatin condensation and reduced mitochondrial membrane potential in resistant KB cells. The results from DNA fragmentation analysis also demonstrated the GLU induced apoptosis in KB cells and its synergy with PTX. Importantly, GLU and/or PTX triggered apoptosis through the activation of pro-apoptotic proteins such as p53, Bax, and caspase-9. Our findings demonstrated for the first time that GLU causes cell death in human oral cancer cells via the ROS-dependent suppression of MDR transporters and p53-mediated activation of the intrinsic mitochondrial pathway of apoptosis. Additionally, the present study also focussed on investigation of the protective effect of GLU and combination drugs in human normal blood lymphocytes. Normal blood lymphocytes assay indicated that GLU is able to induce selective toxicity in cancer cells and in silico molecular docking studies support the choice of GLU as ABC inhibitor to enhance PTX efficacy

  14. Identification of ABC transporter genes conferring combined pleuromutilin-lincosamide-streptogramin A resistance in bovine methicillin-resistant Staphylococcus aureus and coagulase-negative staphylococci.

    PubMed

    Wendlandt, Sarah; Kadlec, Kristina; Feßler, Andrea T; Schwarz, Stefan

    2015-06-12

    The aim of this study was to investigate the genetic basis of combined pleuromutilin-lincosamide-streptogramin A resistance in 26 unrelated methicillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative staphylococci (CoNS) from dairy cows suffering from mastitis. The 26 pleuromutilin-resistant staphylococcal isolates were screened for the presence of the genes vga(A), vga(B), vga(C), vga(E), vga(E) variant, sal(A), vmlR, cfr, lsa(A), lsa(B), lsa(C), and lsa(E) by PCR. None of the 26 isolates carried the genes vga(B), vga(C), vga(E), vga(E) variant, vmlR, cfr, lsa(A), lsa(B), or lsa(C). Two Staphylococcus haemolyticus and single Staphylococcus xylosus, Staphylococcus lentus, and Staphylococcus hominis were vga(A)-positive. Twelve S. aureus, two Staphylococcus warneri, as well as single S. lentus and S. xylosus carried the lsa(E) gene. Moreover, single S. aureus, S. haemolyticus, S. xylosus, and Staphylococcus epidermidis were positive for both genes, vga(A) and lsa(E). The sal(A) gene was found in a single Staphylococcus sciuri. All ABC transporter genes were located in the chromosomal DNA, except for a plasmid-borne vga(A) gene in the S. epidermidis isolate. The genetic environment of the lsa(E)-positive isolates was analyzed using previously described PCR assays. Except for the S. warneri and S. xylosus, all lsa(E)-positive isolates harbored a part of the previously described enterococcal multiresistance gene cluster. This is the first report of the novel lsa(E) gene in the aforementioned bovine CoNS species. This is also the first identification of the sal(A) gene in a S. sciuri from a case of bovine mastitis. Moreover, the sal(A) gene was shown to also confer pleuromutilin resistance. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. A Neisseria meningitidis fbpABC mutant is incapable of using nonheme iron for growth.

    PubMed

    Khun, H H; Kirby, S D; Lee, B C

    1998-05-01

    The neisserial fbpABC locus has been proposed to act as an iron-specific ABC transporter system. To confirm this assigned function, we constructed an fbpABC mutant in Neisseria meningitidis by insertional inactivation of fbpABC with a selectable antibiotic marker. The mutant was unable to use iron supplied from human transferrin, human lactoferrin, or iron chelates. However, the use of iron from heme and human hemoglobin was unimpaired. These results support the obligatory participation of fbpABC in neisserial periplasmic iron transport and do not indicate a role for this genetic locus in the heme iron pathway.

  16. A Neisseria meningitidis fbpABC Mutant Is Incapable of Using Nonheme Iron for Growth

    PubMed Central

    Khun, Heng H.; Kirby, Shane D.; Lee, B. Craig

    1998-01-01

    The neisserial fbpABC locus has been proposed to act as an iron-specific ABC transporter system. To confirm this assigned function, we constructed an fbpABC mutant in Neisseria meningitidis by insertional inactivation of fbpABC with a selectable antibiotic marker. The mutant was unable to use iron supplied from human transferrin, human lactoferrin, or iron chelates. However, the use of iron from heme and human hemoglobin was unimpaired. These results support the obligatory participation of fbpABC in neisserial periplasmic iron transport and do not indicate a role for this genetic locus in the heme iron pathway. PMID:9573125

  17. Department of Transportation Data Communications Requirements Analysis.

    DTIC Science & Technology

    1981-07-01

    National Technical Information Service, Springfield, Virginia 22161. CJ0 us Department of Transportation FdeWAtcMk Adl*lt,. and Systems Research...General Administrative System . .. ................. 4.4 4.1.3 Coast Guard Administrative System . .. ............... 4.6 4.1.4 Transportation Automated...Office System .. .. ............ 4.6 4.1.5 OST Data Transmission Characteristics .. .. ............. 4.6 4.1.6 OST Data Communications

  18. Caenorhabditis elegans ABCRNAi transporters interact genetically with rde-2 and mut-7.

    PubMed

    Sundaram, Prema; Han, Wang; Cohen, Nancy; Echalier, Benjamin; Albin, John; Timmons, Lisa

    2008-02-01

    RNA interference (RNAi) mechanisms are conserved and consist of an interrelated network of activities that not only respond to exogenous dsRNA, but also perform endogenous functions required in the fine tuning of gene expression and in maintaining genome integrity. Not surprisingly, RNAi functions have widespread influences on cellular function and organismal development. Previously, we observed a reduced capacity to mount an RNAi response in nine Caenorhabditis elegans mutants that are defective in ABC transporter genes (ABC(RNAi) mutants). Here, we report an exhaustive study of mutants, collectively defective in 49 different ABC transporter genes, that allowed for the categorization of one additional transporter into the ABC(RNAi) gene class. Genetic complementation tests reveal functions for ABC(RNAi) transporters in the mut-7/rde-2 branch of the RNAi pathway. These second-site noncomplementation interactions suggest that ABC(RNAi) proteins and MUT-7/RDE-2 function together in parallel pathways and/or as multiprotein complexes. Like mut-7 and rde-2, some ABC(RNAi) mutants display transposon silencing defects. Finally, our analyses reveal a genetic interaction network of ABC(RNAi) gene function with respect to this part of the RNAi pathway. From our results, we speculate that the coordinated activities of ABC(RNAi) transporters, through their effects on endogenous RNAi-related mechanisms, ultimately affect chromosome function and integrity.

  19. 75 FR 11991 - ABC & D Recycling, Inc.-Lease and Operation Exemption-a Line of Railroad in Ware, MA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-12

    ... DEPARTMENT OF TRANSPORTATION Surface Transportation Board [STB Finance Docket No. 35356] ABC & D Recycling, Inc.--Lease and Operation Exemption--a Line of Railroad in Ware, MA ABC & D Recycling, Inc. (ABC & D), a noncarrier, has filed a verified notice of exemption under 49 CFR 1150.31 to lease from O...

  20. Statistical Hypothesis Testing in Intraspecific Phylogeography: NCPA versus ABC

    PubMed Central

    Templeton, Alan R.

    2009-01-01

    Nested clade phylogeographic analysis (NCPA) and approximate Bayesian computation (ABC) have been used to test phylogeographic hypotheses. Multilocus NCPA tests null hypotheses, whereas ABC discriminates among a finite set of alternatives. The interpretive criteria of NCPA are explicit and allow complex models to be built from simple components. The interpretive criteria of ABC are ad hoc and require the specification of a complete phylogeographic model. The conclusions from ABC are often influenced by implicit assumptions arising from the many parameters needed to specify a complex model. These complex models confound many assumptions so that biological interpretations are difficult. Sampling error is accounted for in NCPA, but ABC ignores important sources of sampling error that creates pseudo-statistical power. NCPA generates the full sampling distribution of its statistics, but ABC only yields local probabilities, which in turn make it impossible to distinguish between a good fitting model, a non-informative model, and an over-determined model. Both NCPA and ABC use approximations, but convergences of the approximations used in NCPA are well defined whereas those in ABC are not. NCPA can analyze a large number of locations, but ABC cannot. Finally, the dimensionality of tested hypothesis is known in NCPA, but not for ABC. As a consequence, the “probabilities” generated by ABC are not true probabilities and are statistically non-interpretable. Accordingly, ABC should not be used for hypothesis testing, but simulation approaches are valuable when used in conjunction with NCPA or other methods that do not rely on highly parameterized models. PMID:19192182

  1. 9 CFR 88.4 - Requirements for transport.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Section 88.4 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS COMMERCIAL TRANSPORTATION OF EQUINES FOR SLAUGHTER § 88.4 Requirements for transport. (a) Prior to the commercial...

  2. 9 CFR 88.4 - Requirements for transport.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Section 88.4 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS COMMERCIAL TRANSPORTATION OF EQUINES FOR SLAUGHTER § 88.4 Requirements for transport. (a) Prior to the commercial...

  3. 9 CFR 88.4 - Requirements for transport.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Section 88.4 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS COMMERCIAL TRANSPORTATION OF EQUINES FOR SLAUGHTER § 88.4 Requirements for transport. (a) Prior to the commercial...

  4. 9 CFR 88.4 - Requirements for transport.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Section 88.4 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS COMMERCIAL TRANSPORTATION OF EQUINES FOR SLAUGHTER § 88.4 Requirements for transport. (a) Prior to the commercial...

  5. 9 CFR 88.4 - Requirements for transport.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Section 88.4 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS COMMERCIAL TRANSPORTATION OF EQUINES FOR SLAUGHTER § 88.4 Requirements for transport. (a) Prior to the commercial...

  6. Overexpression of an ABC transporter and mutations of GyrA, GyrB, and ParC in contributing to high-level ciprofloxacin resistance in Streptococcus suis type 2.

    PubMed

    Yao, Jie; Shang, Kexin; Huang, Jinhu; Ran, Wei; Kashif, Jam; Wang, Liping

    2014-04-01

    Streptococcus suis is a pathogen of zoonotic diseases. Moreover, the emergence of fluoro-quinolones (FQs) resistance in this pathogen has severe consequences for pigs and human health. In this study, the molecular mechanism of FQs resistance in S. suis type 2 (SS2) sensitive strains isolated from pigs was assessed after in vitro induction of resistance against the most frequently used FQs: ciprofloxacin, norfloxacin, and enrofloxacin. Proteome analysis, sequencing and real-time RT-PCR results strongly established an overexpression of an ABC transporter protein (other than SatAB) and topoisomerase mutations in GyrA (Ser81Arg), GyrB (Glu354Lys), and ParC (Ser79Phe) in contributing to high level ciprofloxacin resistance in SS2. Due to the overexpression of the ABC transporter, intracellular ciprofloxacin concentrations were significantly lower in the resistant strains than those of sensitive strains after 20, 35, and 60 min exposures to ciprofloxacin (p < 0.05). It was concluded that improper use of FQs is one of the main causes of the emergence of this zoonotic pathogen as a multiresistant organism against commonly used antibiotics. The existence of an efflux-like protein is an incentive to find new drug targets to avoid the spread of FQs-resistant S. suis isolates in pigs and the human population.

  7. 10 CFR 11.13 - Special requirements for transportation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Special requirements for transportation. 11.13 Section 11.13 Energy NUCLEAR REGULATORY COMMISSION CRITERIA AND PROCEDURES FOR DETERMINING ELIGIBILITY FOR... Authorization § 11.13 Special requirements for transportation. (a) All individuals who, after 365 days following...

  8. 10 CFR 11.13 - Special requirements for transportation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Special requirements for transportation. 11.13 Section 11.13 Energy NUCLEAR REGULATORY COMMISSION CRITERIA AND PROCEDURES FOR DETERMINING ELIGIBILITY FOR... Authorization § 11.13 Special requirements for transportation. (a) All individuals who, after 365 days following...

  9. 10 CFR 11.13 - Special requirements for transportation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Special requirements for transportation. 11.13 Section 11.13 Energy NUCLEAR REGULATORY COMMISSION CRITERIA AND PROCEDURES FOR DETERMINING ELIGIBILITY FOR... Authorization § 11.13 Special requirements for transportation. (a) All individuals who, after 365 days following...

  10. 10 CFR 11.13 - Special requirements for transportation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Special requirements for transportation. 11.13 Section 11.13 Energy NUCLEAR REGULATORY COMMISSION CRITERIA AND PROCEDURES FOR DETERMINING ELIGIBILITY FOR... Authorization § 11.13 Special requirements for transportation. (a) All individuals who, after 365 days following...

  11. Independent activity of the homologous small regulatory RNAs AbcR1 and AbcR2 in the legume symbiont Sinorhizobium meliloti.

    PubMed

    Torres-Quesada, Omar; Millán, Vicenta; Nisa-Martínez, Rafael; Bardou, Florian; Crespi, Martín; Toro, Nicolás; Jiménez-Zurdo, José I

    2013-01-01

    The legume symbiont Sinorhizobium meliloti expresses a plethora of small noncoding RNAs (sRNAs) whose function is mostly unknown. Here, we have functionally characterized two tandemly encoded S. meliloti Rm1021 sRNAs that are similar in sequence and structure. Homologous sRNAs (designated AbcR1 and AbcR2) have been shown to regulate several ABC transporters in the related α-proteobacteria Agrobacterium tumefaciens and Brucella abortus. In Rm1021, AbcR1 and AbcR2 exhibit divergent unlinked regulation and are stabilized by the RNA chaperone Hfq. AbcR1 is transcribed in actively dividing bacteria, either in culture, rhizosphere or within the invasion zone of mature alfalfa nodules. Conversely, AbcR2 expression is induced upon entry into stationary phase and under abiotic stress. Only deletion of AbcR1 resulted into a discrete growth delay in rich medium, but both are dispensable for symbiosis. Periplasmic proteome profiling revealed down-regulation of the branched-chain amino acid binding protein LivK by AbcR1, but not by AbcR2. A double-plasmid reporter assay confirmed the predicted specific targeting of the 5'-untranslated region of the livK mRNA by AbcR1 in vivo. Our findings provide evidences of independent regulatory functions of these sRNAs, probably to fine-tune nutrient uptake in free-living and undifferentiated symbiotic rhizobia.

  12. Independent Activity of the Homologous Small Regulatory RNAs AbcR1 and AbcR2 in the Legume Symbiont Sinorhizobium meliloti

    PubMed Central

    Torres-Quesada, Omar; Millán, Vicenta; Nisa-Martínez, Rafael; Bardou, Florian; Crespi, Martín; Toro, Nicolás; Jiménez-Zurdo, José I.

    2013-01-01

    The legume symbiont Sinorhizobium meliloti expresses a plethora of small noncoding RNAs (sRNAs) whose function is mostly unknown. Here, we have functionally characterized two tandemly encoded S. meliloti Rm1021 sRNAs that are similar in sequence and structure. Homologous sRNAs (designated AbcR1 and AbcR2) have been shown to regulate several ABC transporters in the related α-proteobacteria Agrobacterium tumefaciens and Brucella abortus. In Rm1021, AbcR1 and AbcR2 exhibit divergent unlinked regulation and are stabilized by the RNA chaperone Hfq. AbcR1 is transcribed in actively dividing bacteria, either in culture, rhizosphere or within the invasion zone of mature alfalfa nodules. Conversely, AbcR2 expression is induced upon entry into stationary phase and under abiotic stress. Only deletion of AbcR1 resulted into a discrete growth delay in rich medium, but both are dispensable for symbiosis. Periplasmic proteome profiling revealed down-regulation of the branched-chain amino acid binding protein LivK by AbcR1, but not by AbcR2. A double-plasmid reporter assay confirmed the predicted specific targeting of the 5′-untranslated region of the livK mRNA by AbcR1 in vivo. Our findings provide evidences of independent regulatory functions of these sRNAs, probably to fine-tune nutrient uptake in free-living and undifferentiated symbiotic rhizobia. PMID:23869210

  13. Regulation of Expression of abcA and Its Response to Environmental Conditions

    PubMed Central

    Villet, Regis A.; Truong-Bolduc, Que Chi; Wang, Yin; Estabrooks, Zoe; Medeiros, Heidi

    2014-01-01

    The ATP-dependent transporter gene abcA in Staphylococcus aureus confers resistance to hydrophobic β-lactams. In strain ISP794, abcA is regulated by the transcriptional regulators MgrA and NorG and shares a 420-nucleotide intercistronic region with the divergently transcribed pbp4 gene, which encodes the transpeptidase Pbp4. Exposure of exponentially growing cells to iron-limited media, oxidative stress, and acidic pH (5.5) for 0.5 to 2 h had no effect on abcA expression. In contrast, nutrient limitation produced a significant increase in abcA transcripts. We identified three additional regulators (SarA, SarZ, and Rot) that bind to the overlapping promoter region of abcA and pbp4 in strain MW2 and investigated their role in the regulation of abcA expression. Expression of abcA is decreased by 10.0-fold in vivo in a subcutaneous abscess model. In vitro, abcA expression depends on rot and sarZ regulators. Moenomycin A exposure of strain MW2 produced an increase in abcA transcripts. Relative to MW2, the MIC of moenomycin was decreased 8-fold for MW2ΔabcA and increased 10-fold for the MW2 abcA overexpresser, suggesting that moenomycin is a substrate of AbcA. PMID:24509312

  14. Consideration of Fuel Requirements for Supersonic Transport Operation

    NASA Technical Reports Server (NTRS)

    Stickle, Joseph W.

    1965-01-01

    An analysis of the interaction of operational environment and aircraft characteristics of the supersonic transport (SST) in the areas of design-range and reserve-fuel requirements has been made. Design-range requirements are considered in relation to the effects of wind, temperature, flight-level assignment, and payload variation. An approach toward combining en route and holding reserve requirements while maintaining protection equivalent to that provided subsonic jet transport operations by the present civil air regulation en route plus holding reserves is given. This approach results in a savings in reserve fuel over that required by separate requirements.

  15. [Hygienic requirements for transportation of industrial waste and consumption residues].

    PubMed

    Metel'skiĭ, S V; Sin'kova, N V

    2009-01-01

    All wishing legal persons and individual entrepreneurs are presently engaged in garbage disposal Sanitary-and-epidemiological examination of activities in transportation of waste is complicated by that the existing sanitary regulations lack no requirements for storage, repair, washing, sanitization of waste-carrying transport, particularly epidemiologically dangerous (domestic, food, and biological waste, animal excreta, cut hair, etc.).

  16. Assessment of the Requirements for Magnesium Transporters in Bacillus subtilis

    PubMed Central

    Wakeman, Catherine A.; Goodson, Jonathan R.; Zacharia, Vineetha M.

    2014-01-01

    Magnesium is the most abundant divalent metal in cells and is required for many structural and enzymatic functions. For bacteria, at least three families of proteins function as magnesium transporters. In recent years, it has been shown that a subset of these transport proteins is regulated by magnesium-responsive genetic control elements. In this study, we investigated the cellular requirements for magnesium homeostasis in the model microorganism Bacillus subtilis. Putative magnesium transporter genes were mutationally disrupted, singly and in combination, in order to assess their general importance. Mutation of only one of these genes resulted in strong dependency on supplemental extracellular magnesium. Notably, this transporter gene, mgtE, is known to be under magnesium-responsive genetic regulatory control. This suggests that the identification of magnesium-responsive genetic mechanisms may generally denote primary transport proteins for bacteria. To investigate whether B. subtilis encodes yet additional classes of transport mechanisms, suppressor strains that permitted the growth of a transporter-defective mutant were identified. Several of these strains were sequenced to determine the genetic basis of the suppressor phenotypes. None of these mutations occurred in transport protein homologues; instead, they affected housekeeping functions, such as signal recognition particle components and ATP synthase machinery. From these aggregate data, we speculate that the mgtE protein provides the primary route of magnesium import in B. subtilis and that the other putative transport proteins are likely to be utilized for more-specialized growth conditions. PMID:24415722

  17. Disruption of the ABC transporter genes PDR5, YOR1, and SNQ2, and their participation in improved fermentative activity of a sake yeast mutant showing pleiotropic drug resistance.

    PubMed

    Watanabe, M; Mizoguchi, H; Nishimura, A

    2000-01-01

    Clotrimazole-resistant mutants from sake yeasts show improved fermentative activity in sake mash and pleiotropic drug resistance (PDR). The PDR mechanism is interpreted by overexpression of ATP-binding cassette (ABC) transporters, which extrude various kinds of drugs out of a cell. In a clotrimazole-resistant mutant, CTZ21, isolated from the haploid sake yeast HL69, the levels of mRNA for three major ABC transporter genes, PDR5, SNQ2, and YOR1, markedly increased. These three genes of CTZ21 were disrupted to investigate which participated in the improved fermentative activity of CTZ21. The fermentative activities of deltapdr5 and deltasnq2 strains of CTZ21 were reduced to that of HL69 in the initial and middle stages of fermentation. In the last stage, however, the sake meter [(1/gravity - 1) x 1443] of the deltapdr5 and deltasnq2 strains rose faster than that of HL69. On the other hand, a deltayor1 strain of CTZ21 fermented sake mash in a manner nearly identical to that of CTZ21 until the last stage of fermentation. But in the last stage, fermentation of the deltayor1 slowed down compared with that of CTZ21. A deltayor1 strain of HL69 also exhibited much reduced fermentative activity in the middle and last fermentation stages. The YOR1 gene seems necessary for sake fermentation to be completed efficiently. The ATP content in sake mash brewed with CTZ21 was drastically decreased throughout the whole fermentation period. This low ATP level was restored to a medium level in the cases of both the deltapdr5 and deltasnq2 strains of CTZ21. In contrast, the deltayor1 of CTZ21 exhibited a low ATP level in sake mash in the same manner as CTZ21. These results suggest that the low ATP level of CTZ21 contributes to a certain extent its improved fermentative activity in the initial and middle stages of sake fermentation.

  18. The Yersinia pestis Siderophore, Yersiniabactin, and the ZnuABC system both contribute to Zinc acquisition and the development of lethal septicemic plague in mice

    PubMed Central

    Bobrov, Alexander G.; Kirillina, Olga; Fetherston, Jacqueline D.; Miller, M. Clarke; Burlison, Joseph A.; Perry, Robert D.

    2014-01-01

    Summary Bacterial pathogens must overcome host sequestration of zinc (Zn2+), an essential micronutrient, during the infectious disease process. While the mechanisms to acquire chelated Zn2+ by bacteria are largely undefined, many pathogens rely upon the ZnuABC family of ABC transporters. Here we show that in Yersinia pestis, irp2, a gene encoding the synthetase (HMWP2) for the siderophore yersiniabactin (Ybt) is required for growth under Zn2+-deficient conditions in a strain lacking ZnuABC. Moreover, growth stimulation with exogenous, purified apo-Ybt provides evidence that Ybt may serve as a zincophore for Zn2+ acquisition. Studies with the Zn2+-dependent transcriptional reporter znuA∷lacZ indicate that the ability to synthesize Ybt affects the levels of intracellular Zn2+. However, the outer membrane receptor Psn and TonB as well as the inner membrane (IM) ABC transporter YbtPQ, that are required for Fe3+ acquisition by Ybt, are not needed for Ybt-dependent Zn2+ uptake. In contrast, the predicted IM protein YbtX, a member of the Major Facilitator Superfamily, was essential for Ybt-dependent Zn2+ uptake. Finally, we show that the ZnuABC system and the Ybt synthetase HMWP2, presumably by Ybt synthesis, both contribute to the development of a lethal infection in a septicemic plague mouse model. PMID:24979062

  19. The Yersinia pestis siderophore, yersiniabactin, and the ZnuABC system both contribute to zinc acquisition and the development of lethal septicaemic plague in mice.

    PubMed

    Bobrov, Alexander G; Kirillina, Olga; Fetherston, Jacqueline D; Miller, M Clarke; Burlison, Joseph A; Perry, Robert D

    2014-08-01

    Bacterial pathogens must overcome host sequestration of zinc (Zn(2+) ), an essential micronutrient, during the infectious disease process. While the mechanisms to acquire chelated Zn(2+) by bacteria are largely undefined, many pathogens rely upon the ZnuABC family of ABC transporters. Here we show that in Yersinia pestis, irp2, a gene encoding the synthetase (HMWP2) for the siderophore yersiniabactin (Ybt) is required for growth under Zn(2+) -deficient conditions in a strain lacking ZnuABC. Moreover, growth stimulation with exogenous, purified apo-Ybt provides evidence that Ybt may serve as a zincophore for Zn(2+) acquisition. Studies with the Zn(2+) -dependent transcriptional reporter znuA::lacZ indicate that the ability to synthesize Ybt affects the levels of intracellular Zn(2+) . However, the outer membrane receptor Psn and TonB as well as the inner membrane (IM) ABC transporter YbtPQ, which are required for Fe(3+) acquisition by Ybt, are not needed for Ybt-dependent Zn(2+) uptake. In contrast, the predicted IM protein YbtX, a member of the Major Facilitator Superfamily, was essential for Ybt-dependent Zn(2+) uptake. Finally, we show that the ZnuABC system and the Ybt synthetase HMWP2, presumably by Ybt synthesis, both contribute to the development of a lethal infection in a septicaemic plague mouse model. © 2014 John Wiley & Sons Ltd.

  20. Material requirements for the High Speed Civil Transport

    NASA Technical Reports Server (NTRS)

    Stephens, Joseph R.; Hecht, Ralph J.; Johnson, Andrew M.

    1993-01-01

    Under NASA-sponsored High Speed Research (HSR) programs, the materials and processing requirements have been identified for overcoming the environmental and economic barriers of the next generation High Speed Civil Transport (HSCT) propulsion system. The long (2 to 5 hours) supersonic cruise portion of the HSCT cycle will place additional durability requirements on all hot section engine components. Low emissions combustor designs will require high temperature ceramic matrix composite liners to meet an emission goal of less than 5g NO(x) per Kg fuel burned. Large axisymmetric and two-dimensional exhaust nozzle designs are now under development to meet or exceed FAR 36 Stage III noise requirements, and will require lightweight, high temperature metallic, intermetallic, and ceramic matrix composites to reduce nozzle weight and meet structural and acoustic component performance goals. This paper describes and discusses the turbomachinery, combustor, and exhaust nozzle requirements of the High Speed Civil Transport propulsion system.

  1. Identification of two inner-membrane proteins required for the transport of lipopolysaccharide to the outer membrane of Escherichia coli

    PubMed Central

    Ruiz, Natividad; Gronenberg, Luisa S.; Kahne, Daniel; Silhavy, Thomas J.

    2008-01-01

    The outer membrane (OM) of most Gram-negative bacteria contains lipopolysaccharide (LPS) in the outer leaflet. LPS, or endotoxin, is a molecule of important biological activities. In the host, LPS elicits a potent immune response, while in the bacterium, it plays a crucial role by establishing a barrier to limit entry of hydrophobic molecules. Before LPS is assembled at the OM, it must be synthesized at the inner membrane (IM) and transported across the aqueous periplasmic compartment. Much is known about the biosynthesis of LPS but, until recently, little was known about its transport and assembly. We applied a reductionist bioinformatic approach that takes advantage of the small size of the proteome of the Gram-negative endosymbiont Blochmannia floridanus to search for novel factors involved in OM biogenesis. This led to the discovery of two essential Escherichia coli IM proteins of unknown function, YjgP and YjgQ, which are required for the transport of LPS to the cell surface. We propose that these two proteins, which we have renamed LptF and LptG, respectively, are the missing transmembrane components of the ABC transporter that, together with LptB, functions to extract LPS from the IM en route to the OM. PMID:18375759

  2. Identification of two inner-membrane proteins required for the transport of lipopolysaccharide to the outer membrane of Escherichia coli.

    PubMed

    Ruiz, Natividad; Gronenberg, Luisa S; Kahne, Daniel; Silhavy, Thomas J

    2008-04-08

    The outer membrane (OM) of most Gram-negative bacteria contains lipopolysaccharide (LPS) in the outer leaflet. LPS, or endotoxin, is a molecule of important biological activities. In the host, LPS elicits a potent immune response, while in the bacterium, it plays a crucial role by establishing a barrier to limit entry of hydrophobic molecules. Before LPS is assembled at the OM, it must be synthesized at the inner membrane (IM) and transported across the aqueous periplasmic compartment. Much is known about the biosynthesis of LPS but, until recently, little was known about its transport and assembly. We applied a reductionist bioinformatic approach that takes advantage of the small size of the proteome of the Gram-negative endosymbiont Blochmannia floridanus to search for novel factors involved in OM biogenesis. This led to the discovery of two essential Escherichia coli IM proteins of unknown function, YjgP and YjgQ, which are required for the transport of LPS to the cell surface. We propose that these two proteins, which we have renamed LptF and LptG, respectively, are the missing transmembrane components of the ABC transporter that, together with LptB, functions to extract LPS from the IM en route to the OM.

  3. ABC's of Construction. Final Report.

    ERIC Educational Resources Information Center

    Greater Baton Rouge Chamber of Commerce, LA.

    The ABC's of Construction project was a demonstration project designed to integrate basic skills training with an industry-developed vocational-craft training program. The program was located at the central training facility of the Pelican Chapter of Associated Builders and Contractors (ABC), an organization made up of nearly 300 member companies…

  4. Do You Know Your ABC?

    ERIC Educational Resources Information Center

    Neale, Claire

    2013-01-01

    Within primary schools, the core subjects of literacy and numeracy are highly regarded, and rightly so, as children need to learn to read, write and be numerically literate. This means that all children learn their ABCs at an early age, But, what about the "other ABC"--"Airway, Breathing and Circulation?" Accidents and medical…

  5. Identification of a new biocontrol gene in Trichoderma atroviride: the role of an ABC transporter membrane pump in the interaction with different plant-pathogenic fungi.

    PubMed

    Ruocco, Michelina; Lanzuise, Stefania; Vinale, Francesco; Marra, Roberta; Turrà, David; Woo, Sheridan Lois; Lorito, Matteo

    2009-03-01

    Successful biocontrol interactions often require that the beneficial microbes involved are resistant or tolerant to a variety of toxicants, including antibiotics produced by themselves or phytopathogens, plant antimicrobial compounds, and synthetic chemicals or contaminants. The ability of Trichoderma spp., the most widely applied biocontrol fungi, to withstand different chemical stresses, including those associated with mycoparasitism, is well known. In this work, we identified an ATP-binding cassette transporter cell membrane pump as an important component of the above indicated resistance mechanisms that appears to be supported by an extensive and powerful cell detoxification system. The encoding gene, named Taabc2, was cloned from a strain of Trichoderma atroviride and characterized. Its expression was found to be upregulated in the presence of pathogen-secreted metabolites, specific mycotoxins and some fungicides, and in conditions that stimulate the production in Trichoderma spp. of antagonism-related factors (toxins and enzymes). The key role of this gene in antagonism and biocontrol was demonstrated by the characterization of the obtained deletion mutants. They suffered an increased susceptibility to inhibitory compounds either secreted by pathogenic fungi or possibly produced by the biocontrol microbe itself and lost, partially or entirely, the ability to protect tomato plants from Pythium ultimum and Rhizoctonia solani attack.

  6. Aerothermodynamic testing requirements for future space transportation systems

    NASA Technical Reports Server (NTRS)

    Paulson, John W., Jr.; Miller, Charles G., III

    1995-01-01

    Aerothermodynamics, encompassing aerodynamics, aeroheating, and fluid dynamic and physical processes, is the genesis for the design and development of advanced space transportation vehicles. It provides crucial information to other disciplines involved in the development process such as structures, materials, propulsion, and avionics. Sources of aerothermodynamic information include ground-based facilities, computational fluid dynamic (CFD) and engineering computer codes, and flight experiments. Utilization of this triad is required to provide the optimum requirements while reducing undue design conservatism, risk, and cost. This paper discusses the role of ground-based facilities in the design of future space transportation system concepts. Testing methodology is addressed, including the iterative approach often required for the assessment and optimization of configurations from an aerothermodynamic perspective. The influence of vehicle shape and the transition from parametric studies for optimization to benchmark studies for final design and establishment of the flight data book is discussed. Future aerothermodynamic testing requirements including the need for new facilities are also presented.

  7. Glymphatic solute transport does not require bulk flow

    PubMed Central

    Asgari, Mahdi; de Zélicourt, Diane; Kurtcuoglu, Vartan

    2016-01-01

    Observations of fast transport of fluorescent tracers in mouse brains have led to the hypothesis of bulk water flow directed from arterial to venous paravascular spaces (PVS) through the cortical interstitium. At the same time, there is evidence for interstitial solute transport by diffusion rather than by directed bulk fluid motion. It has been shown that the two views may be consolidated by intracellular water flow through astrocyte networks combined with mainly diffusive extracellular transport of solutes. This requires the presence of a driving force that has not been determined to date, but for which arterial pulsation has been suggested as the origin. Here we show that arterial pulsation caused by pulse wave propagation is an unlikely origin of this hypothetical driving force. However, we further show that such pulsation may still lead to fast para-arterial solute transport through dispersion, that is, through the combined effect of local mixing and diffusion in the para-arterial space. PMID:27929105

  8. Nonattainment and Ozone Transport Region (OTR) SIP Requirements

    EPA Pesticide Factsheets

    The Clean Air Act (CAA) requires a group of northeast states, which make up the Ozone Transport Region (OTR), to submit a SIP and install a certain level of controls for the pollutants that form ozone, even if they meet ozone standards.

  9. Mycobacterium tuberculosis universal stress protein Rv2623 interacts with the putative ATP binding cassette (ABC) transporter Rv1747 to regulate mycobacterial growth.

    PubMed

    Glass, Lisa N; Swapna, Ganduri; Chavadi, Sivagami Sundaram; Tufariello, JoAnn M; Mi, Kaixia; Drumm, Joshua E; Lam, TuKiet T; Zhu, Guofeng; Zhan, Chenyang; Vilchéze, Catherine; Arcos, Jesus; Chen, Yong; Bi, Lijun; Mehta, Simren; Porcelli, Steven A; Almo, Steve C; Yeh, Syun-Ru; Jacobs, William R; Torrelles, Jordi B; Chan, John

    2017-07-01

    We have previously shown that the Mycobacterium tuberculosis universal stress protein Rv2623 regulates mycobacterial growth and may be required for the establishment of tuberculous persistence. Here, yeast two-hybrid and affinity chromatography experiments have demonstrated that Rv2623 interacts with one of the two forkhead-associated domains (FHA I) of Rv1747, a putative ATP-binding cassette transporter annotated to export lipooligosaccharides. FHA domains are signaling protein modules that mediate protein-protein interactions to modulate a wide variety of biological processes via binding to conserved phosphorylated threonine (pT)-containing oligopeptides of the interactors. Biochemical, immunochemical and mass spectrometric studies have shown that Rv2623 harbors pT and specifically identified threonine 237 as a phosphorylated residue. Relative to wild-type Rv2623 (Rv2623WT), a mutant protein in which T237 has been replaced with a non-phosphorylatable alanine (Rv2623T237A) exhibits decreased interaction with the Rv1747 FHA I domain and diminished growth-regulatory capacity. Interestingly, compared to WT bacilli, an M. tuberculosis Rv2623 null mutant (ΔRv2623) displays enhanced expression of phosphatidyl-myo-inositol mannosides (PIMs), while the ΔRv1747 mutant expresses decreased levels of PIMs. Animal studies have previously shown that ΔRv2623 is hypervirulent, while ΔRv1747 is growth-attenuated. Collectively, these data have provided evidence that Rv2623 interacts with Rv1747 to regulate mycobacterial growth; and this interaction is mediated via the recognition of the conserved Rv2623 pT237-containing FHA-binding motif by the Rv1747 FHA I domain. The divergent aberrant PIM profiles and the opposing in vivo growth phenotypes of ΔRv2623 and ΔRv1747, together with the annotated lipooligosaccharide exporter function of Rv1747, suggest that Rv2623 interacts with Rv1747 to modulate mycobacterial growth by negatively regulating the activity of Rv1747; and that Rv

  10. Estrogen receptor α is required for oviductal transport of embryos

    PubMed Central

    Li, Shuai; O’Neill, Sofia R. S.; Zhang, Yong; Holtzman, Michael J.; Takemaru, Ken-Ichi; Korach, Kenneth S.; Winuthayanon, Wipawee

    2017-01-01

    Newly fertilized embryos spend the first few days within the oviduct and are transported to the uterus, where they implant onto the uterine wall. An implantation of the embryo before reaching the uterus could result in ectopic pregnancy and lead to maternal death. Estrogen is necessary for embryo transport in mammals; however, the mechanism involved in estrogen-mediated cellular function within the oviduct remains unclear. In this study, we show in mouse models that ciliary length and beat frequency of the oviductal epithelial cells are regulated through estrogen receptor α (ESR1) but not estrogen receptor β (ESR2). Gene profiling indicated that transcripts in the WNT/β-catenin (WNT/CTNNB1) signaling pathway were regulated by estrogen in mouse oviduct, and inhibition of this pathway in a whole oviduct culture system resulted in a decreased embryo transport distance. However, selective ablation of CTNNB1 from the oviductal ciliated cells did not affect embryo transport, possibly because of a compensatory mechanism via intact CTNNB1 in the adjacent secretory cells. In summary, we demonstrated that disruption of estrogen signaling in oviductal epithelial cells alters ciliary function and impairs embryo transport. Therefore, our findings may provide a better understanding of etiology of the ectopic pregnancy that is associated with alteration of estrogen signals.—Li, S., O’Neill, S. R. S., Zhang, Y., Holtzman, M. J., Takemaru, K.-I., Korach, K. S., Winuthayanon, W. Estrogen receptor α is required for oviductal transport of embryos. PMID:28082352

  11. Space Transportation System Availability Requirement and Its Influencing Attributes Relationships

    NASA Technical Reports Server (NTRS)

    Rhodes, Russell E.; Adams, Timothy C.; McCleskey, Carey M.

    2008-01-01

    It is important that engineering and management accept the need for an availability requirement that is derived with its influencing attributes. It is the intent of this paper to provide the visibility of relationships of these major attribute drivers (variables) to each other and the resultant system inherent availability. Also important to provide bounds of the variables providing engineering the insight required to control the system's engineering solution, e.g., these influencing attributes become design requirements also. These variables will drive the need to provide integration of similar discipline functions or technology selection to allow control of the total parts count. The relationship of selecting a reliability requirement will place a constraint on parts count to achieve a given availability requirement or if allowed to increase the parts count will drive the system reliability requirement higher. They also provide the understanding for the relationship of mean repair time (or mean down time) to maintainability, e.g., accessibility for repair, and both the mean time between failure, e.g., reliability of hardware and availability. The concerns and importance of achieving a strong availability requirement is driven by the need for affordability, the choice of using the two launch solution for the single space application, or the need to control the spare parts count needed to support the long stay in either orbit or on the surface of the moon. Understanding the requirements before starting the architectural design concept will avoid considerable time and money required to iterate the design to meet the redesign and assessment process required to achieve the results required of the customer's space transportation system. In fact the impact to the schedule to being able to deliver the system that meets the customer's needs, goals, and objectives may cause the customer to compromise his desired operational goal and objectives resulting in considerable

  12. Space Transportation System Availability Requirements and Its Influencing Attributes Relationships

    NASA Technical Reports Server (NTRS)

    Rhodes, Russell E.; Adams, Timothy C.; McCleskey, Carey M.

    2008-01-01

    It is important that engineering and management accept the need for an availability requirement that is derived with its influencing attributes. It is the intent of this paper to provide the visibility of relationships of these major attribute drivers (variables) to each other and the resultant system inherent availability. Also important to provide bounds of the variables providing engineering the insight required to control the system's engineering solution, e.g., these influencing attributes become design requirements also. These variables will drive the need to provide integration of similar discipline functions or technology selection to allow control of the total parts count. The relationship of selecting a reliability requirement will place a constraint on parts count to achieve a given availability requirement or if allowed to increase the parts count will drive the system reliability requirement higher. They also provide the understanding for the relationship of mean repair time (or mean down time) to maintainability, e.g., accessibility for repair, and both the mean time between failure, e.g., reliability of hardware and availability. The concerns and importance of achieving a strong availability requirement is driven by the need for affordability, the choice of using the two launch solution for the single space application, or the need to control the spare parts count needed to support the long stay in either orbit or on the surface of the moon. Understanding the requirements before starting the architectural design concept will avoid considerable time and money required to iterate the design to meet the redesign and assessment process required to achieve the results required of the customer's space transportation system. In fact the impact to the schedule to being able to deliver the system that meets the customer's needs, goals, and objectives may cause the customer to compromise his desired operational goal and objectives resulting in considerable

  13. The ABCs of Sex Ed.

    ERIC Educational Resources Information Center

    Sroka, Stephen R.

    2002-01-01

    Cites statistics on extent of sexually transmitted diseases and pregnancies among adolescents; describes ideological dispute over how to teach sex education; advocates teaching the ABCs of sex education: Abstinence, Be Monogamous, and Condoms. (PKP)

  14. 49 CFR 176.704 - Requirements relating to transport indices and criticality safety indices.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Requirements relating to transport indices and... Requirements relating to transport indices and criticality safety indices. (a) The sum of the transport indices..., transport and unloading are to be supervised by persons qualified in the transport of radioactive material...

  15. 49 CFR 176.704 - Requirements relating to transport indices and criticality safety indices.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Requirements relating to transport indices and... Requirements relating to transport indices and criticality safety indices. (a) The sum of the transport indices..., transport and unloading are to be supervised by persons qualified in the transport of radioactive material...

  16. Post-Golgi anterograde transport requires GARP-dependent endosome-to-TGN retrograde transport.

    PubMed

    Hirata, Tetsuya; Fujita, Morihisa; Nakamura, Shota; Gotoh, Kazuyoshi; Motooka, Daisuke; Murakami, Yoshiko; Maeda, Yusuke; Kinoshita, Taroh

    2015-09-01

    The importance of endosome-to-trans-Golgi network (TGN) retrograde transport in the anterograde transport of proteins is unclear. In this study, genome-wide screening of the factors necessary for efficient anterograde protein transport in human haploid cells identified subunits of the Golgi-associated retrograde protein (GARP) complex, a tethering factor involved in endosome-to-TGN transport. Knockout (KO) of each of the four GARP subunits, VPS51-VPS54, in HEK293 cells caused severely defective anterograde transport of both glycosylphosphatidylinositol (GPI)-anchored and transmembrane proteins from the TGN. Overexpression of VAMP4, v-SNARE, in VPS54-KO cells partially restored not only endosome-to-TGN retrograde transport, but also anterograde transport of both GPI-anchored and transmembrane proteins. Further screening for genes whose overexpression normalized the VPS54-KO phenotype identified TMEM87A, encoding an uncharacterized Golgi-resident membrane protein. Overexpression of TMEM87A or its close homologue TMEM87B in VPS54-KO cells partially restored endosome-to-TGN retrograde transport and anterograde transport. Therefore GARP- and VAMP4-dependent endosome-to-TGN retrograde transport is required for recycling of molecules critical for efficient post-Golgi anterograde transport of cell-surface integral membrane proteins. In addition, TMEM87A and TMEM87B are involved in endosome-to-TGN retrograde transport. © 2015 Hirata, Fujita, et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  17. Hydrogen for the subsonic transport. [aircraft design and fuel requirements

    NASA Technical Reports Server (NTRS)

    Korycinski, P. F.; Snow, D. B.

    1975-01-01

    Relations between air travel and fuel requirements are examined. Alternate fuels considered in connection with problems related to a diminishing supply of petroleum include synthetic jet fuel, methane, and hydrogen. A cruise flight of a subsonic aircraft on a hydrogen-fueled jet engine was demonstrated in 1957. However, more development work is required to provide a sound engineering base for a complete air transportation system using hydrogen as fuel. Aircraft designs for alternate fuels are discussed, giving attention to hydrogen-related technology already available and new developments which are needed.

  18. Vibrio cholerae NspS, a homologue of ABC-type periplasmic solute binding proteins, facilitates transduction of polyamine signals independent of their transport

    PubMed Central

    Cockerell, Steven R.; Rutkovsky, Alex C.; Zayner, Josiah P.; Cooper, Rebecca E.; Porter, Lindsay R.; Pendergraft, Sam S.; Parker, Zach M.; McGinnis, Marcus W.

    2014-01-01

    The polyamines norspermidine and spermidine are among the environmental signals that regulate Vibrio cholerae biofilm formation. The effects of these polyamines are mediated by NspS, a member of the bacterial periplasmic solute binding protein superfamily. Almost all members of this superfamily characterized to date are components of ATP-binding cassette-type transporters involved in nutrient uptake. Consequently, in the current annotation of the V. cholerae genome, NspS has been assigned a function in transport. The objective of this study was to further characterize NspS and investigate its potential role in transport. Our results support a role for NspS in signal transduction in response to norspermidine and spermidine, but not their transport. In addition, we provide evidence that these polyamine signals are processed by c-di-GMP signalling networks in the cell. Furthermore, we present comparative genomics analyses which reveal the presence of NspS-like proteins in a variety of bacteria, suggesting that periplasmic ligand binding proteins may be widely utilized for sensory transduction. PMID:24530989

  19. Uptake of L-cystine via an ABC transporter contributes defense of oxidative stress in the L-cystine export-dependent manner in Escherichia coli.

    PubMed

    Ohtsu, Iwao; Kawano, Yusuke; Suzuki, Marina; Morigasaki, Susumu; Saiki, Kyohei; Yamazaki, Shunsuke; Nonaka, Gen; Takagi, Hiroshi

    2015-01-01

    Intracellular thiols like L-cystine and L-cystine play a critical role in the regulation of cellular processes. Here we show that Escherichia coli has two L-cystine transporters, the symporter YdjN and the ATP-binding cassette importer FliY-YecSC. These proteins import L-cystine, an oxidized product of L-cystine from the periplasm to the cytoplasm. The symporter YdjN, which is expected to be a new member of the L-cystine regulon, is a low affinity L-cystine transporter (Km = 1.1 μM) that is mainly involved in L-cystine uptake from outside as a nutrient. E. coli has only two L-cystine importers because ΔydjNΔyecS mutant cells are not capable of growing in the minimal medium containing L-cystine as a sole sulfur source. Another protein YecSC is the FliY-dependent L-cystine transporter that functions cooperatively with the L-cystine transporter YdeD, which exports L-cystine as reducing equivalents from the cytoplasm to the periplasm, to prevent E. coli cells from oxidative stress. The exported L-cystine can reduce the periplasmic hydrogen peroxide to water, and then generated L-cystine is imported back into the cytoplasm via the ATP-binding cassette transporter YecSC with a high affinity to L-cystine (Km = 110 nM) in a manner dependent on FliY, the periplasmic L-cystine-binding protein. The double disruption of ydeD and fliY increased cellular levels of lipid peroxides. From these findings, we propose that the hydrogen peroxide-inducible L-cystine/L-cystine shuttle system plays a role of detoxification of hydrogen peroxide before lipid peroxidation occurs, and then might specific prevent damage to membrane lipids.

  20. Accelerated bridge construction (ABC) decision making and economic modeling tool.

    DOT National Transportation Integrated Search

    2011-12-01

    In this FHWA-sponsored pool funded study, a set of decision making tools, based on the Analytic Hierarchy Process (AHP) was developed. This tool set is prepared for transportation specialists and decision-makers to determine if ABC is more effective ...

  1. Requirement for Coenzyme Q in Plasma Membrane Electron Transport

    NASA Astrophysics Data System (ADS)

    Sun, I. L.; Sun, E. E.; Crane, F. L.; Morre, D. J.; Lindgren, A.; Low, H.

    1992-12-01

    Coenzyme Q is required in the electron transport system of rat hepatocyte and human erythrocyte plasma membranes. Extraction of coenzyme Q from the membrane decreases NADH dehydrogenase and NADH:oxygen oxidoreductase activity. Addition of coenzyme Q to the extracted membrane restores the activity. Partial restoration of activity is also found with α-tocopherylquinone, but not with vitamin K_1. Analogs of coenzyme Q inhibit NADH dehydrogenase and oxidase activity and the inhibition is reversed by added coenzyme Q. Ferricyanide reduction by transmembrane electron transport from HeLa cells is inhibited by coenzyme Q analogs and restored with added coenzyme Q10. Reduction of external ferricyanide and diferric transferrin by HeLa cells is accompanied by proton release from the cells. Inhibition of the reduction by coenzyme Q analogs also inhibits the proton release, and coenzyme Q10 restores the proton release activity. Trans-plasma membrane electron transport stimulates growth of serum-deficient cells, and added coenzyme Q10 increases growth of HeLa (human adenocarcinoma) and BALB/3T3 (mouse fibroblast) cells. The evidence is consistent with a function for coenzyme Q in a trans-plasma membrane electron transport system which influences cell growth.

  2. Space Transportation System Availability Requirements and Its Influencing Attributes Relationships

    NASA Technical Reports Server (NTRS)

    Rhodes, Russel E.; Adams, TImothy C.

    2008-01-01

    It is essential that management and engineering understand the need for an availability requirement for the customer's space transportation system as it enables the meeting of his needs, goal, and objectives. There are three types of availability, e.g., operational availability, achieved availability, or inherent availability. The basic definition of availability is equal to the mean uptime divided by the sum of the mean uptime plus the mean downtime. The major difference is the inclusiveness of the functions within the mean downtime and the mean uptime. This paper will address tIe inherent availability which only addresses the mean downtime as that mean time to repair or the time to determine the failed article, remove it, install a replacement article and verify the functionality of the repaired system. The definitions of operational availability include the replacement hardware supply or maintenance delays and other non-design factors in the mean downtime. Also with inherent availability the mean uptime will only consider the mean time between failures (other availability definitions consider this as mean time between maintenance - preventive and corrective maintenance) that requires the repair of the system to be functional. It is also essential that management and engineering understand all influencing attributes relationships to each other and to the resultant inherent availability requirement. This visibility will provide the decision makers with the understanding necessary to place constraints on the design definition for the major drivers that will determine the inherent availability, safety, reliability, maintainability, and the life cycle cost of the fielded system provided the customer. This inherent availability requirement may be driven by the need to use a multiple launch approach to placing humans on the moon or the desire to control the number of spare parts required to support long stays in either orbit or on the surface of the moon or mars. It is

  3. Cystathionine β-Synthase (CBS) Domains 1 and 2 Fulfill Different Roles in Ionic Strength Sensing of the ATP-binding Cassette (ABC) Transporter OpuA*

    PubMed Central

    Karasawa, Akira; Erkens, Guus B.; Berntsson, Ronnie P.-A.; Otten, Renee; Schuurman-Wolters, Gea K.; Mulder, Frans A. A.; Poolman, Bert

    2011-01-01

    The cystathionine β-synthase module of OpuA in conjunction with an anionic membrane surface acts as a sensor of internal ionic strength, which allows the protein to respond to osmotic stress. We now show by chemical modification and cross-linking studies that CBS2-CBS2 interface residues are critical for transport activity and/or ionic regulation of transport, whereas CBS1 serves no functional role. We establish that Cys residues in CBS1, CBS2, and the nucleotide-binding domain are more accessible for cross-linking at high than low ionic strength, indicating that these domains undergo conformational changes when transiting between the active and inactive state. Structural analyses suggest that the cystathionine β-synthase module is largely unstructured. Moreover, we could substitute CBS1 by a linker and preserve ionic regulation of transport. These data suggest that CBS1 serves as a linker and the structured CBS2-CBS2 interface forms a hinge point for ionic strength-dependent rearrangements that are transmitted to the nucleotide-binding domain and thereby affect translocation activity. PMID:21878634

  4. Retinoid Binding Properties of Nucleotide Binding Domain 1 of the Stargardt Disease-associated ATP Binding Cassette (ABC) Transporter, ABCA4*

    PubMed Central

    Biswas-Fiss, Esther E.; Affet, Stephanie; Ha, Malissa; Biswas, Subhasis B.

    2012-01-01

    The retina-specific ATP binding cassette transporter, ABCA4 protein, is associated with a broad range of inherited macular degenerations, including Stargardt disease, autosomal recessive cone rod dystrophy, and fundus flavimaculatus. In order to understand its role in retinal transport in rod out segment discs, we have investigated the interactions of the soluble domains of ABCA4 with both 11-cis- and all-trans-retinal. Using fluorescence anisotropy-based binding analysis and recombinant polypeptides derived from the amino acid sequences of the four soluble domains of ABCA4, we demonstrated that the nucleotide binding domain 1 (NBD1) specifically bound 11-cis-retinal. Its affinity for all-trans-retinal was markedly reduced. Stargardt disease-associated mutations in this domain resulted in attenuation of 11-cis-retinal binding. Significant differences in 11-cis-retinal binding affinities were observed between NBD1 and other cytoplasmic and lumenal domains of ABCA4. The results suggest a possible role of ABCA4 and, in particular, the NBD1 domain in 11-cis-retinal binding. These results also correlate well with a recent report on the in vivo role of ABCA4 in 11-cis-retinal transport. PMID:23144455

  5. Genome-Wide Identification and Expression Profiling of ATP-Binding Cassette (ABC) Transporter Gene Family in Pineapple (Ananas comosus (L.) Merr.) Reveal the Role of AcABCG38 in Pollen Development

    PubMed Central

    Chen, Piaojuan; Li, Yi; Zhao, Lihua; Hou, Zhimin; Yan, Maokai; Hu, Bingyan; Liu, Yanhui; Azam, Syed Muhammad; Zhang, Ziyan; Rahman, Zia ur; Liu, Liping; Qin, Yuan

    2017-01-01

    Pineapple (Ananas comosus L.) cultivation commonly relies on asexual reproduction which is easily impeded by many factors in agriculture production. Sexual reproduction might be a novel approach to improve the pineapple planting. However, genes controlling pineapple sexual reproduction are still remain elusive. In different organisms a conserved superfamily proteins known as ATP binding cassette (ABC) participate in various biological processes. Whereas, till today the ABC gene family has not been identified in pineapple. Here 100 ABC genes were identified in the pineapple genome and grouped into eight subfamilies (5 ABCAs, 20 ABCBs, 16 ABCCs, 2 ABCDs, one ABCEs, 5 ABCFs, 42 ABCGs and 9 ABCIs). Gene expression profiling revealed the dynamic expression pattern of ABC gene family in various tissues and different developmental stages. AcABCA5, AcABCB6, AcABCC4, AcABCC7, AcABCC9, AcABCG26, AcABCG38 and AcABCG42 exhibited preferential expression in ovule and stamen. Over-expression of AcABCG38 in the Arabidopsis double mutant abcg1-2abcg16-2 partially restored its pollen abortion defects, indicating that AcABCG38 plays important roles in pollen development. Our study on ABC gene family in pineapple provides useful information for developing sexual pineapple plantation which could be utilized to improve pineapple agricultural production. PMID:29312399

  6. Genome-Wide Identification and Expression Profiling of ATP-Binding Cassette (ABC) Transporter Gene Family in Pineapple (Ananas comosus (L.) Merr.) Reveal the Role of AcABCG38 in Pollen Development.

    PubMed

    Chen, Piaojuan; Li, Yi; Zhao, Lihua; Hou, Zhimin; Yan, Maokai; Hu, Bingyan; Liu, Yanhui; Azam, Syed Muhammad; Zhang, Ziyan; Rahman, Zia Ur; Liu, Liping; Qin, Yuan

    2017-01-01

    Pineapple ( Ananas comosus L .) cultivation commonly relies on asexual reproduction which is easily impeded by many factors in agriculture production. Sexual reproduction might be a novel approach to improve the pineapple planting. However, genes controlling pineapple sexual reproduction are still remain elusive. In different organisms a conserved superfamily proteins known as ATP binding cassette (ABC) participate in various biological processes. Whereas, till today the ABC gene family has not been identified in pineapple. Here 100 ABC genes were identified in the pineapple genome and grouped into eight subfamilies (5 ABCAs , 20 ABCB s, 16 ABCCs , 2 ABCDs , one ABCEs , 5 ABCFs , 42 ABCGs and 9 ABCIs ). Gene expression profiling revealed the dynamic expression pattern of ABC gene family in various tissues and different developmental stages. AcABCA5, AcABCB6, AcABCC4 , AcABCC7 , AcABCC9 , AcABCG26 , AcABCG38 and AcABCG42 exhibited preferential expression in ovule and stamen. Over-expression of AcABCG38 in the Arabidopsis double mutant abcg1-2abcg16-2 partially restored its pollen abortion defects, indicating that AcABCG38 plays important roles in pollen development. Our study on ABC gene family in pineapple provides useful information for developing sexual pineapple plantation which could be utilized to improve pineapple agricultural production.

  7. ATP-binding Cassette (ABC) Transport System Solute-binding Protein-guided Identification of Novel d-Altritol and Galactitol Catabolic Pathways in Agrobacterium tumefaciens C58*

    PubMed Central

    Wichelecki, Daniel J.; Vetting, Matthew W.; Chou, Liyushang; Al-Obaidi, Nawar; Bouvier, Jason T.; Almo, Steven C.; Gerlt, John A.

    2015-01-01

    Innovations in the discovery of the functions of uncharacterized proteins/enzymes have become increasingly important as advances in sequencing technology flood protein databases with an exponentially growing number of open reading frames. This study documents one such innovation developed by the Enzyme Function Initiative (EFI; U54GM093342), the use of solute-binding proteins for transport systems to identify novel metabolic pathways. In a previous study, this strategy was applied to the tripartite ATP-independent periplasmic transporters. Here, we apply this strategy to the ATP-binding cassette transporters and report the discovery of novel catabolic pathways for d-altritol and galactitol in Agrobacterium tumefaciens C58. These efforts resulted in the description of three novel enzymatic reactions as follows: 1) oxidation of d-altritol to d-tagatose via a dehydrogenase in Pfam family PF00107, a previously unknown reaction; 2) phosphorylation of d-tagatose to d-tagatose 6-phosphate via a kinase in Pfam family PF00294, a previously orphan EC number; and 3) epimerization of d-tagatose 6-phosphate C-4 to d-fructose 6-phosphate via a member of Pfam family PF08013, another previously unknown reaction. The epimerization reaction catalyzed by a member of PF08013 is especially noteworthy, because the functions of members of PF08013 have been unknown. These discoveries were assisted by the following two synergistic bioinformatics web tools made available by the Enzyme Function Initiative: the EFI-Enzyme Similarity Tool and the EFI-Genome Neighborhood Tool. PMID:26472925

  8. The ABC protein turned chloride channel whose failure causes cystic fibrosis

    NASA Astrophysics Data System (ADS)

    Gadsby, David C.; Vergani, Paola; Csanády, László

    2006-03-01

    CFTR chloride channels are encoded by the gene mutated in patients with cystic fibrosis. These channels belong to the superfamily of ABC transporter ATPases. ATP-driven conformational changes, which in other ABC proteins fuel uphill substrate transport across cellular membranes, in CFTR open and close a gate to allow transmembrane flow of anions down their electrochemical gradient. New structural and biochemical information from prokaryotic ABC proteins and functional information from CFTR channels has led to a unifying mechanism explaining those ATP-driven conformational changes.

  9. ATP and AMP Mutually Influence Their Interaction with the ATP-binding Cassette (ABC) Adenylate Kinase Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) at Separate Binding Sites*

    PubMed Central

    Randak, Christoph O.; Dong, Qian; Ver Heul, Amanda R.; Elcock, Adrian H.; Welsh, Michael J.

    2013-01-01

    Cystic fibrosis transmembrane conductance regulator (CFTR) is an anion channel in the ATP-binding cassette (ABC) transporter protein family. In the presence of ATP and physiologically relevant concentrations of AMP, CFTR exhibits adenylate kinase activity (ATP + AMP ⇆ 2 ADP). Previous studies suggested that the interaction of nucleotide triphosphate with CFTR at ATP-binding site 2 is required for this activity. Two other ABC proteins, Rad50 and a structural maintenance of chromosome protein, also have adenylate kinase activity. All three ABC adenylate kinases bind and hydrolyze ATP in the absence of other nucleotides. However, little is known about how an ABC adenylate kinase interacts with ATP and AMP when both are present. Based on data from non-ABC adenylate kinases, we hypothesized that ATP and AMP mutually influence their interaction with CFTR at separate binding sites. We further hypothesized that only one of the two CFTR ATP-binding sites is involved in the adenylate kinase reaction. We found that 8-azidoadenosine 5′-triphosphate (8-N3-ATP) and 8-azidoadenosine 5′-monophosphate (8-N3-AMP) photolabeled separate sites in CFTR. Labeling of the AMP-binding site with 8-N3-AMP required the presence of ATP. Conversely, AMP enhanced photolabeling with 8-N3-ATP at ATP-binding site 2. The adenylate kinase active center probe P1,P5-di(adenosine-5′) pentaphosphate interacted simultaneously with an AMP-binding site and ATP-binding site 2. These results show that ATP and AMP interact with separate binding sites but mutually influence their interaction with the ABC adenylate kinase CFTR. They further indicate that the active center of the adenylate kinase comprises ATP-binding site 2. PMID:23921386

  10. Down-regulation of aminopeptidase N and ABC transporter subfamily G transcripts in Cry1Ab and Cry1Ac resistant Asian corn borer, Ostrinia furnacalis (Lepidoptera: Crambidae)

    PubMed Central

    Zhang, Tiantao; Coates, Brad S.; Wang, Yueqin; Wang, Yidong; Bai, Shuxiong; Wang, Zhenying; He, Kanglai

    2017-01-01

    The Asian corn borer (ACB), Ostrinia furnacalis (Lepidoptera: Crambidae), is a highly destructive pest of cultivated maize throughout East Asia. Bacillus thuringiensis (Bt) crystalline protein (Cry) toxins cause mortality by a mechanism involving pore formation or signal transduction following toxin binding to receptors along the midgut lumen of susceptible insects, but this mechanism and mutations therein that lead to resistance are not fully understood. In the current study, quantitative comparisons were made among midgut expressed transcripts from O. furnacalis susceptible (ACB-BtS) and laboratory selected strains resistant to Cry1Ab (ACB-AbR) and Cry1Ac toxins (ACB-AcR) when feeding on non-Bt diet. From a combined de novo transcriptome assembly of 83,370 transcripts, ORFs of ≥ 100 amino acids were predicted and annotated for 28,940 unique isoforms derived from 12,288 transcripts. Transcriptome-wide expression estimated from RNA-seq read depths predicted significant down-regulation of transcripts for previously known Bt resistance genes, aminopeptidase N1 (apn1) and apn3, as well as a putative ATP binding cassette transporter group G (abcg) gene in both ACB-AbR and -AcR (log2[fold-change] ≥ 1.36; P < 0.0001). The transcripts that were most highly differentially regulated in both ACB-AbR and -AcR compared to ACB-BtS (log2[fold-change] ≥ 2.0; P < 0.0001) included up- and down-regulation of serine proteases, storage proteins and cytochrome P450 monooxygenases, as well as up-regulation of genes with predicted transport function. This study predicted the significant down-regulation of transcripts for previously known Bt resistance genes, aminopeptidase N1 (apn1) and apn3, as well as abccg gene in both ACB-AbR and -AcR. These data are important for the understanding of systemic differences between Bt resistant and susceptible genotypes. PMID:28808417

  11. ABC-transporters are localized in caveolin-1-positive and reggie-1-negative and reggie-2-negative microdomains of the canalicular membrane in rat hepatocytes.

    PubMed

    Ismair, Manfred G; Häusler, Stephanie; Stuermer, Claudia A; Guyot, Christelle; Meier, Peter J; Roth, Jürgen; Stieger, Bruno

    2009-05-01

    The canalicular plasma membrane is constantly exposed to bile acids acting as detergents. Bile acids are essential to mediate release of biliary lipids from the canalicular membrane. Membrane microdomains (previously called lipid rafts) are biochemically defined by their resistance to detergent solubilization at cold temperature. We aimed to investigate the canalicular plasma membrane for the presence of microdomains, which could protect this membrane against the detergent action of bile acids. Highly purified rat liver canalicular plasma membrane vesicles were extracted with 1% Triton X-100 or 1% Lubrol WX at 4 degrees C and subjected to flotation through sucrose step gradients. Both detergents yielded detergent-resistant membranes containing the microdomain markers alkaline phosphatase and sphingomyelin. However, cholesterol was resistant to Lubrol WX solubilization, whereas it was only marginally resistant to solubilization by Triton X-100. The microdomain marker caveolin-1 was localized to the canalicular plasma membrane domain and was resistant to Lubrol WX, but to a large extent solubilized by Triton X-100. The two additional microdomain markers, reggie-1 and reggie-2, were localized to the basolateral and canalicular plasma membrane and were partially resistant to Lubrol WX but resistant to Triton X-100. The canalicular transporters bile salt export pump, multidrug resistance protein 2, multidrug resistance-associated protein 2, and Abcg5 were largely resistant to Lubrol WX but were solubilized by Triton X-100. These results indicate the presence of two different types of microdomains in the canalicular plasma membrane: "Lubrol-microdomains" and "Triton-microdomains". "Lubrol-microdomains" contain the machinery for canalicular bile formation and may be the starting place for canalicular lipid secretion.

  12. Inhibition of cholesterol absorption associated with a PPAR alpha-dependent increase in ABC binding cassette transporter A1 in mice.

    PubMed

    Knight, Brian L; Patel, Dilip D; Humphreys, Sandy M; Wiggins, David; Gibbons, Geoffrey F

    2003-11-01

    Dietary supplementation with the peroxisome proliferator-activated receptor alpha (PPAR alpha) ligand WY 14,643 gave rise to a 4- to 5-fold increase in the expression of mRNA for the ATP binding cassette transporter A1 (ABCA1) in the intestine of normal mice. There was no effect in the intestine of PPAR alpha-null mice. Consumption of a high-cholesterol diet also increased intestinal ABCA1 expression. The effects of WY 14,643 and the high-cholesterol diet were not additive. WY 14,643 feeding reduced intestinal absorption of cholesterol in the normal mice, irrespective of the dietary cholesterol concentration, and this resulted in lower diet-derived cholesterol and cholesteryl ester concentrations in plasma and liver. At each concentration of dietary cholesterol, there was a similar significant inverse correlation between intestinal ABCA1 mRNA content and the amount of cholesterol absorbed. The fibrate-induced changes in the intestines of the normal mice were accompanied by an increased concentration of the mRNA encoding the sterol-regulatory element binding protein-1c gene (SREBP-1c), a known target gene for the oxysterol receptor liver X receptor alpha (LXR alpha). There was a correlation between intestinal ABCA1 mRNA and SREBP-1c mRNA contents, but not between SREBP-1c mRNA content and cholesterol absorption. These results suggest that PPAR alpha influences cholesterol absorption through modulating ABCA1 activity in the intestine by a mechanism involving LXR alpha.

  13. The ABCs of Student Engagement

    ERIC Educational Resources Information Center

    Parsons, Seth A.; Nuland, Leila Richey; Parsons, Allison Ward

    2014-01-01

    Student engagement is an important consideration for teachers and administrators because it is explicitly associated with achievement. What the authors call the ABC's of engagement they outline as: Affective engagement, Behavioral engagement, and Cognitive engagement. They also present "Three Things Every Teacher Needs to Know about…

  14. Electrokinesis is a microbial behavior that requires extracellular electron transport

    PubMed Central

    Harris, H. W.; El-Naggar, M. Y.; Bretschger, O.; Ward, M. J.; Romine, M. F.; Obraztsova, A. Y.; Nealson, K. H.

    2009-01-01

    We report a previously undescribed bacterial behavior termed electrokinesis. This behavior was initially observed as a dramatic increase in cell swimming speed during reduction of solid MnO2 particles by the dissimilatory metal-reducing bacterium Shewanella oneidensis MR-1. The same behavioral response was observed when cells were exposed to small positive applied potentials at the working electrode of a microelectrochemical cell and could be tuned by adjusting the potential on the working electrode. Electrokinesis was found to be different from both chemotaxis and galvanotaxis but was absent in mutants defective in electron transport to solid metal oxides. Using in situ video microscopy and cell tracking algorithms, we have quantified the response for different strains of Shewanella and shown that the response correlates with current-generating capacity in microbial fuel cells. The electrokinetic response was only exhibited by a subpopulation of cells closest to the MnO2 particles or electrodes. In contrast, the addition of 1 mM 9,10-anthraquinone-2,6-disulfonic acid, a soluble electron shuttle, led to increases in motility in the entire population. Electrokinesis is defined as a behavioral response that requires functional extracellular electron transport and that is observed as an increase in cell swimming speeds and lengthened paths of motion that occur in the proximity of a redox active mineral surface or the working electrode of an electrochemical cell. PMID:20018675

  15. Follow-On Technology Requirement Study for Advanced Subsonic Transport

    NASA Technical Reports Server (NTRS)

    Wendus, Bruce E.; Stark, Donald F.; Holler, Richard P.; Funkhouser, Merle E.

    2003-01-01

    A study was conducted to define and assess the critical or enabling technologies required for a year 2005 entry into service (EIS) engine for subsonic commercial aircraft, with NASA Advanced Subsonic Transport goals used as benchmarks. The year 2005 EIS advanced technology engine is an Advanced Ducted Propulsor (ADP) engine. Performance analysis showed that the ADP design offered many advantages compared to a baseline turbofan engine. An airplane/ engine simulation study using a long range quad aircraft quantified the effects of the ADP engine on the economics of typical airline operation. Results of the economic analysis show the ADP propulsion system provides a 6% reduction in direct operating cost plus interest, with half the reduction resulting from reduced fuel consumption. Critical and enabling technologies for the year 2005 EIS ADP were identified and prioritized.

  16. Light transport and general aviation aircraft icing research requirements

    NASA Technical Reports Server (NTRS)

    Breeze, R. K.; Clark, G. M.

    1981-01-01

    A short term and a long term icing research and technology program plan was drafted for NASA LeRC based on 33 separate research items. The specific items listed resulted from a comprehensive literature search, organized and assisted by a computer management file and an industry/Government agency survey. Assessment of the current facilities and icing technology was accomplished by presenting summaries of ice sensitive components and protection methods; and assessments of penalty evaluation, the experimental data base, ice accretion prediction methods, research facilities, new protection methods, ice protection requirements, and icing instrumentation. The intent of the research plan was to determine what icing research NASA LeRC must do or sponsor to ultimately provide for increased utilization and safety of light transport and general aviation aircraft.

  17. Arterial intelligent transportation systems : infrastructure elements and traveler information requirements.

    DOT National Transportation Integrated Search

    2009-08-01

    Applying Intelligent Transportation Systems (ITS) to arterial systems allows TxDOT to significantly enhance : transportation system operation efficiency and improve traffic mobility. However, no guidelines are available to : assist TxDOT staff in sel...

  18. Functional requirements for a comprehensive transportation location referencing system

    DOT National Transportation Integrated Search

    2000-06-01

    Transportation agencies manage data that is referenced in one, two, three, and four dimensions. Location referencing system (LRS) data models vary across transportation agencies and often within organizations as well. This has resulted in failed atte...

  19. Projecting Labor Requirements for Transportation-Related Construction. Final Report.

    ERIC Educational Resources Information Center

    Washington Technical Inst., Washington, DC. Center for Urban Services.

    This report examines the urban transportation planning process and its labor market impact, including projections of opportunities for minority participation in construction, operation, and maintenance of a transportation system and forecasts of training needed in critical occupations. It was found that transportation-related construction may be…

  20. Requirements for transportation of fast pyrolysis bio-oil in Finland

    NASA Astrophysics Data System (ADS)

    Karhunen, Antti; Laihanen, Mika; Ranta, Tapio

    2016-11-01

    The purpose of this paper is to discuss the requirements and challenges of pyrolysis oil's transportation in Finland. Pyrolysis oil is a new type of renewable liquid fuel that can be utilised in applications such as heat and electricity production. It has never been transported on a large scale in Finland. Possible options are transport by road, rail and waterway. The most significant requirements in its transportation are created by acidity and high density of pyrolysis oil, which impose requirements for the materials and transport equipment. The study described here shows that constant domestic transportation of pyrolysis oil is most reasonably operated with tank trucks. Rail-based transport may have potential for domestic fixed routes, and transport by water could be utilised in exporting. All transportation methods have limitations and advantages relative to each other. Ultimately, the production site and end-user's locations will determine the most suitable transport method.

  1. 19 CFR 122.117 - Requirements for transit air cargo transport.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Requirements for transit air cargo transport. 122... Requirements for transit air cargo transport. (a) Transportation—(1) Port to port. Transit air cargo may be... cargo, a receipt shall be given. The receipt shall be made by the airline responsible for transport or...

  2. 19 CFR 122.117 - Requirements for transit air cargo transport.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Requirements for transit air cargo transport. 122... Requirements for transit air cargo transport. (a) Transportation—(1) Port to port. Transit air cargo may be... cargo, a receipt shall be given. The receipt shall be made by the airline responsible for transport or...

  3. The relationship of title VI requirements to Florida's transportation planning process.

    DOT National Transportation Integrated Search

    2011-10-01

    The Florida Department of Transportation (FDOT) and metropolitan planning organizations (MPO) in Florida are : required to address Title VI and environmental justice (EJ) in the transportation planning process. This study : reviews those practices an...

  4. Application of activity-based costing (ABC) for a Peruvian NGO healthcare provider.

    PubMed

    Waters, H; Abdallah, H; Santillán, D

    2001-01-01

    This article describes the application of activity-based costing (ABC) to calculate the unit costs of the services for a health care provider in Peru. While traditional costing allocates overhead and indirect costs in proportion to production volume or to direct costs, ABC assigns costs through activities within an organization. ABC uses personnel interviews to determine principal activities and the distribution of individual's time among these activities. Indirect costs are linked to services through time allocation and other tracing methods, and the result is a more accurate estimate of unit costs. The study concludes that applying ABC in a developing country setting is feasible, yielding results that are directly applicable to pricing and management. ABC determines costs for individual clinics, departments and services according to the activities that originate these costs, showing where an organization spends its money. With this information, it is possible to identify services that are generating extra revenue and those operating at a loss, and to calculate cross subsidies across services. ABC also highlights areas in the health care process where efficiency improvements are possible. Conclusions about the ultimate impact of the methodology are not drawn here, since the study was not repeated and changes in utilization patterns and the addition of new clinics affected applicability of the results. A potential constraint to implementing ABC is the availability and organization of cost information. Applying ABC efficiently requires information to be readily available, by cost category and department, since the greatest benefits of ABC come from frequent, systematic application of the methodology in order to monitor efficiency and provide feedback for management. The article concludes with a discussion of the potential applications of ABC in the health sector in developing countries.

  5. 49 CFR 176.720 - Requirements for carriage of INF cargo in international transportation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Requirements for carriage of INF cargo in... Requirements for carriage of INF cargo in international transportation. In addition to all other applicable requirements of this subchapter, a vessel carrying INF cargo (see § 176.2, under INF cargo definition) in...

  6. 49 CFR 176.720 - Requirements for carriage of INF cargo in international transportation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Requirements for carriage of INF cargo in... Requirements for carriage of INF cargo in international transportation. In addition to all other applicable requirements of this subchapter, a vessel carrying INF cargo (see § 176.2, under INF cargo definition) in...

  7. 49 CFR 176.720 - Requirements for carriage of INF cargo in international transportation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Requirements for carriage of INF cargo in... Requirements for carriage of INF cargo in international transportation. In addition to all other applicable requirements of this subchapter, a vessel carrying INF cargo (see § 176.2, under INF cargo definition) in...

  8. 49 CFR 176.720 - Requirements for carriage of INF cargo in international transportation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Requirements for carriage of INF cargo in... Requirements for carriage of INF cargo in international transportation. In addition to all other applicable requirements of this subchapter, a vessel carrying INF cargo (see § 176.2, under INF cargo definition) in...

  9. 49 CFR 176.720 - Requirements for carriage of INF cargo in international transportation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Requirements for carriage of INF cargo in... Requirements for carriage of INF cargo in international transportation. In addition to all other applicable requirements of this subchapter, a vessel carrying INF cargo (see § 176.2, under INF cargo definition) in...

  10. CD147 Required for Corneal Endothelial Lactate Transport

    PubMed Central

    Li, Shimin; Nguyen, Tracy T.; Bonanno, Joseph A.

    2014-01-01

    Purpose. CD147/basigin is a chaperone for lactate:H+ cotransporters (monocarboxylate transporters) MCT1 and MCT4. We tested the hypothesis that MCT1 and -4 in corneal endothelium contribute to lactate efflux from stroma to anterior chamber and that silencing CD147 expression would cause corneal edema. Methods. CD147 was silenced via small interfering ribonucleic acid (siRNA) transfection of rabbit corneas ex vivo and anterior chamber lenti-small hairpin RNA (shRNA) pseudovirus in vivo. CD147 and MCT expression was examined by Western blot, RT-PCR, and immunofluorescence. Functional effects were examined by measuring lactate-induced cell acidification, corneal lactate efflux, [lactate], central cornea thickness (CCT), and Azopt (a carbonic anhydrase inhibitor) sensitivity. Results. In ex vivo corneas, 100 nM CD147 siRNA reduced CD147, MCT1, and MCT4 expression by 85%, 79%, and 73%, respectively, while MCT2 expression was unaffected. CD147 siRNA decreased lactate efflux from 3.9 ± 0.81 to 1.5 ± 0.37 nmol/min, increased corneal [lactate] from 19.28 ± 7.15 to 56.73 ± 8.97 nmol/mg, acidified endothelial cells (pHi = 6.83 ± 0.07 vs. 7.19 ± 0.09 in control), and slowed basolateral lactate-induced acidification from 0.0034 ± 0.0005 to 0.0012 ± 0.0005 pH/s, whereas apical acidification was unchanged. In vivo, CD147 shRNA increased CCT by 28.1 ± 0.9 μm at 28 days; Azopt increased CCT to 24.4 ± 3.12 vs. 12.0 ± 0.48 μm in control, and corneal [lactate] was 47.63 ± 6.29 nmol/mg in shCD147 corneas and 17.82 ± 4.93 nmol/mg in paired controls. Conclusions. CD147 is required for the expression of MCT1 and MCT4 in the corneal endothelium. Silencing CD147 slows lactate efflux, resulting in stromal lactate accumulation and corneal edema, consistent with lactate efflux as a significant component of the corneal endothelial pump. PMID:24970254

  11. CD147 required for corneal endothelial lactate transport.

    PubMed

    Li, Shimin; Nguyen, Tracy T; Bonanno, Joseph A

    2014-06-26

    CD147/basigin is a chaperone for lactate:H(+) cotransporters (monocarboxylate transporters) MCT1 and MCT4. We tested the hypothesis that MCT1 and -4 in corneal endothelium contribute to lactate efflux from stroma to anterior chamber and that silencing CD147 expression would cause corneal edema. CD147 was silenced via small interfering ribonucleic acid (siRNA) transfection of rabbit corneas ex vivo and anterior chamber lenti-small hairpin RNA (shRNA) pseudovirus in vivo. CD147 and MCT expression was examined by Western blot, RT-PCR, and immunofluorescence. Functional effects were examined by measuring lactate-induced cell acidification, corneal lactate efflux, [lactate], central cornea thickness (CCT), and Azopt (a carbonic anhydrase inhibitor) sensitivity. In ex vivo corneas, 100 nM CD147 siRNA reduced CD147, MCT1, and MCT4 expression by 85%, 79%, and 73%, respectively, while MCT2 expression was unaffected. CD147 siRNA decreased lactate efflux from 3.9 ± 0.81 to 1.5 ± 0.37 nmol/min, increased corneal [lactate] from 19.28 ± 7.15 to 56.73 ± 8.97 nmol/mg, acidified endothelial cells (pHi = 6.83 ± 0.07 vs. 7.19 ± 0.09 in control), and slowed basolateral lactate-induced acidification from 0.0034 ± 0.0005 to 0.0012 ± 0.0005 pH/s, whereas apical acidification was unchanged. In vivo, CD147 shRNA increased CCT by 28.1 ± 0.9 μm at 28 days; Azopt increased CCT to 24.4 ± 3.12 vs. 12.0 ± 0.48 μm in control, and corneal [lactate] was 47.63 ± 6.29 nmol/mg in shCD147 corneas and 17.82 ± 4.93 nmol/mg in paired controls. CD147 is required for the expression of MCT1 and MCT4 in the corneal endothelium. Silencing CD147 slows lactate efflux, resulting in stromal lactate accumulation and corneal edema, consistent with lactate efflux as a significant component of the corneal endothelial pump. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  12. 40 CFR 761.211 - Manifest system-Transporter requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) TOXIC SUBSTANCES CONTROL ACT POLYCHLORINATED BIPHENYLS (PCBs) MANUFACTURING, PROCESSING, DISTRIBUTION IN COMMERCE, AND USE PROHIBITIONS PCB Waste Disposal Records and Reports § 761.211 Manifest system—Transporter... storage or disposal facility owned or operated by the generator of the PCB waste. (2) [Reserved] (b...

  13. 40 CFR 761.211 - Manifest system-Transporter requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) TOXIC SUBSTANCES CONTROL ACT POLYCHLORINATED BIPHENYLS (PCBs) MANUFACTURING, PROCESSING, DISTRIBUTION IN COMMERCE, AND USE PROHIBITIONS PCB Waste Disposal Records and Reports § 761.211 Manifest system—Transporter... storage or disposal facility owned or operated by the generator of the PCB waste. (2) [Reserved] (b...

  14. 78 FR 53712 - Surface Transportation Project Delivery Program Application Requirements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-30

    ... the 21st Century Act (MAP-21), which converted the Surface Transportation Project Delivery Pilot... signed into law the Moving Ahead for Progress in the 21st Century Act (MAP-21), Public Law 112-141, 126... days from the date of MAP-21's enactment (October 1, 2012)--the regulations concerning the information...

  15. 24 CFR 3280.904 - Specific requirements for designing the transportation system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... the transportation system. 3280.904 Section 3280.904 Housing and Urban Development Regulations... SAFETY STANDARDS Transportation § 3280.904 Specific requirements for designing the transportation system. (a) General. The entire system (frame, drawbar and coupling mechanism, running gear assembly, and...

  16. 28 CFR 97.16 - Clothing requirements for transported violent prisoners.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Clothing requirements for transported... transported violent prisoners. Companies covered under this part must ensure that all violent prisoners they transport are clothed in brightly colored clothing that clearly identifies them as violent prisoners, unless...

  17. 28 CFR 97.16 - Clothing requirements for transported violent prisoners.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Clothing requirements for transported... transported violent prisoners. Companies covered under this part must ensure that all violent prisoners they transport are clothed in brightly colored clothing that clearly identifies them as violent prisoners, unless...

  18. Fast vesicle transport is required for the slow axonal transport of synapsin.

    PubMed

    Tang, Yong; Scott, David; Das, Utpal; Gitler, Daniel; Ganguly, Archan; Roy, Subhojit

    2013-09-25

    Although it is known that cytosolic/soluble proteins synthesized in cell bodies are transported at much lower overall velocities than vesicles in fast axonal transport, the fundamental basis for this slow movement is unknown. Recently, we found that cytosolic proteins in axons of mouse cultured neurons are conveyed in a manner that superficially resembles diffusion, but with a slow anterograde bias that is energy- and motor-dependent (Scott et al., 2011). Here we show that slow axonal transport of synapsin, a prototypical member of this rate class, is dependent upon fast vesicle transport. Despite the distinct overall dynamics of slow and fast transport, experimentally induced and intrinsic variations in vesicle transport have analogous effects on slow transport of synapsin as well. Dynamic cotransport of vesicles and synapsin particles is also seen in axons, consistent with a model where higher-order assemblies of synapsin are conveyed by transient and probabilistic associations with vesicles moving in fast axonal transport. We posit that such dynamic associations generate the slow overall anterogradely biased flow of the population ("dynamic-recruitment model"). Our studies uncover the underlying kinetic basis for a classic cytosolic/soluble protein moving in slow axonal transport and reveal previously unknown links between slow and fast transport, offering a clearer conceptual picture of this curious phenomenon.

  19. 25 CFR 39.720 - Why are there different reporting requirements for transportation data?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... there different reporting requirements for transportation data? In order to construct an actual cost data base, residential and day schools must report data required by §§ 39.721 and 39.722. ... transportation data? 39.720 Section 39.720 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR EDUCATION...

  20. 25 CFR 39.720 - Why are there different reporting requirements for transportation data?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... there different reporting requirements for transportation data? In order to construct an actual cost data base, residential and day schools must report data required by §§ 39.721 and 39.722. ... transportation data? 39.720 Section 39.720 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR EDUCATION...

  1. 25 CFR 39.720 - Why are there different reporting requirements for transportation data?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... there different reporting requirements for transportation data? In order to construct an actual cost data base, residential and day schools must report data required by §§ 39.721 and 39.722. ... transportation data? 39.720 Section 39.720 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR EDUCATION...

  2. 25 CFR 39.720 - Why are there different reporting requirements for transportation data?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... there different reporting requirements for transportation data? In order to construct an actual cost data base, residential and day schools must report data required by §§ 39.721 and 39.722. ... transportation data? 39.720 Section 39.720 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR EDUCATION...

  3. 25 CFR 39.720 - Why are there different reporting requirements for transportation data?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... there different reporting requirements for transportation data? In order to construct an actual cost data base, residential and day schools must report data required by §§ 39.721 and 39.722. ... transportation data? 39.720 Section 39.720 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR EDUCATION...

  4. ATP-binding cassette (ABC) proteins in aquatic invertebrates: Evolutionary significance and application in marine ecotoxicology.

    PubMed

    Jeong, Chang-Bum; Kim, Hui-Su; Kang, Hye-Min; Lee, Jae-Seong

    2017-04-01

    The ATP-binding cassette (ABC) protein superfamily is known to play a fundamental role in biological processes and is highly conserved across animal taxa. The ABC proteins function as active transporters for multiple substrates across the cellular membrane by ATP hydrolysis. As this superfamily is derived from a common ancestor, ABC genes have evolved via lineage-specific duplications through the process of adaptation. In this review, we summarized information about the ABC gene families in aquatic invertebrates, considering their evolution and putative functions in defense mechanisms. Phylogenetic analysis was conducted to examine the evolutionary significance of ABC gene families in aquatic invertebrates. Particularly, a massive expansion of multixenobiotic resistance (MXR)-mediated efflux transporters was identified in the absence of the ABCG2 (BCRP) gene in Ecdysozoa and Platyzoa, suggesting that a loss of Abcg2 gene occurred sporadically in these species during divergence of Protostome to Lophotrochozoa. Furthermore, in aquatic invertebrates, the ecotoxicological significance of MXR is discussed while considering the role of MXR-mediated efflux transporters in response to various environmental pollutants. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Water Transportation Requirements for Coal Movement in the 1980's

    DOT National Transportation Integrated Search

    1976-12-01

    This report develops and presents barge industry estimates of additional equipment and facilities required to handle a projected doubling of coal traffic. It also describes present coal flows, associated operational policies and practices, and the in...

  6. Global energy transports and the influence of clouds on transport requirements - A satellite analysis

    NASA Technical Reports Server (NTRS)

    Sohn, Byung-Ju; Smith, Eric A.

    1992-01-01

    This report investigates the impact of differential net radiative heating on 2D energy transports within the atmosphere ocean system and the role of clouds on this process. The 2D mean energy transports, in answer to zonal and meridional gradients in the net radiation field, show an east-west coupled dipole structure in which the Pacific acts as the major energy source and North Africa as the major energy sink. It is demonstrated that the dipole is embedded in the secondary energy transports arising mainly from the differential heating between land and oceans in the tropics in which the tropical east-west (zonal) transports are up to 30 percent of the tropical north-south (meridional) transports.

  7. Brassboard Astrometric Beam Combiner (ABC) Development for the Space Interferometry Mission (SIM)

    NASA Technical Reports Server (NTRS)

    Jeganathan, Muthu; Kuan, Gary; Rud, Mike; Lin, Sean; Sutherland, Kristen; Moore, James; An, Xin

    2008-01-01

    The Astrometric Beam Combiner (ABC) is a critical element of the Space Interferometry Mission (SIM) that performs three key functions: coherently combine starlight from two siderostats; individually detect starlight for angle tracking; and disperse and detect the interferometric fringes. In addition, the ABC contains: a stimulus, cornercubes and shutters for in-orbit calibration; several tip/tilt mirror mechanisms for in-orbit alignment; and internal metrology beam launcher for pathlength monitoring. The detailed design of the brassboard ABC (which has the form, fit and function of the flight unit) is complete, procurement of long-lead items is underway, and assembly and testing is expected to be completed in Spring 2009. In this paper, we present the key requirements for the ABC, details of the completed optical and mechanical design as well as plans for assembly and alignment.

  8. Requirements for Ion and Solute Transport, and pH Regulation During Enamel Maturation

    PubMed Central

    LACRUZ, RODRIGO S.; SMITH, CHARLES E.; MOFFATT, PIERRE; CHANG, EUGENE H.; BROMAGE, TIMOTHY G.; BRINGAS, PABLO; NANCI, ANTONIO; BANIWAL, SANJEEV K.; ZABNER, JOSEPH; WELSH, MICHAEL J.; KURTZ, IRA; PAINE, MICHAEL L.

    2012-01-01

    Transcellular bicarbonate transport is suspected to be an important pathway used by ameloblasts to regulate extracellular pH and support crystal growth during enamel maturation. Proteins that play a role in amelogenesis include members of the ABC transporters (SLC gene family and CFTR). A number of carbonic anhydrases (CAs) have also been identified. The defined functions of these genes are likely interlinked during enamel mineralization. The purpose of this study is to quantify relative mRNA levels of individual SLC, Cftr, and CAs in enamel cells obtained from secretory and maturation stages on rat incisors. We also present novel data on the enamel phenotypes for two animal models, amutant porcine(CFTR-ΔF508) and the NBCe1-null mouse.Our data show that two SLCs(AE2 and NBCe1),Cftr,and Car2, Car3,Car6,and Car12 are all significantly up-regulated at the onset of the maturation stage of amelogenesis when compared to the secretory stage. The remaining SLCs and CA gene transcripts showed negligible expression or no significant change in expression from secretory to maturation stages. The enamel of Cftr-ΔF508 adult pigs was hypomineralized and showed abnormal crystal growth. NBCe1-null mice enamel was structurally defective and had a marked decrease in mineral content relative to wild-type. These data demonstrate the importance of many non-matrix proteins to amelogenesis and that the expression levels of multiple genes regulating extracellular pH are modulated during enamel maturation in response to an increased need for pH buffering during hydroxyapatite crystal growth. PMID:21732355

  9. The feoABC Locus of Yersinia pestis Likely Has Two Promoters Causing Unique Iron Regulation

    PubMed Central

    O'Connor, Lauren; Fetherston, Jacqueline D.; Perry, Robert D.

    2017-01-01

    The FeoABC ferrous transporter is a wide-spread bacterial system. While the feoABC locus is regulated by a number of factors in the bacteria studied, we have previously found that regulation of feoABC in Yersinia pestis appears to be unique. None of the non-iron responsive transcriptional regulators that control expression of feoABC in other bacteria do so in Y. pestis. Another unique factor is the iron and Fur regulation of the Y. pestis feoABC locus occurs during microaerobic but not aerobic growth. Here we show that this unique iron-regulation is not due to a unique aspect of the Y. pestis Fur protein but to DNA sequences that regulate transcription. We have used truncations, alterations, and deletions of the feoA::lacZ reporter to assess the mechanism behind the failure of iron to repress transcription under aerobic conditions. These studies plus EMSAs and DNA sequence analysis have led to our proposal that the feoABC locus has two promoters: an upstream P1 promoter whose expression is relatively iron-independent but repressed under microaerobic conditions and the known downstream Fur-regulated P2 promoter. In addition, we have identified two regions that bind Y. pestis protein(s), although we have not identified these protein(s) or their function. Finally we used iron uptake assays to demonstrate that both FeoABC and YfeABCD transport ferrous iron in an energy-dependent manner and also use ferric iron as a substrate for uptake. PMID:28785546

  10. Step 2: Know Your Diabetes ABCs

    MedlinePlus

    ... please turn JavaScript on. Feature: Type 2 Diabetes Step 2: Know Your Diabetes ABCs Past Issues / Fall ... 2 Diabetes" Articles Diabetes Is Serious But Manageable / Step 1: Learn About Diabetes / Step 2: Know Your ...

  11. 40 CFR 271.11 - Requirements for transporters of hazardous wastes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... hazardous wastes. 271.11 Section 271.11 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) REQUIREMENTS FOR AUTHORIZATION OF STATE HAZARDOUS WASTE PROGRAMS Requirements for Final Authorization § 271.11 Requirements for transporters of hazardous wastes. (a) The State...

  12. 40 CFR 271.11 - Requirements for transporters of hazardous wastes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... hazardous wastes. 271.11 Section 271.11 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) REQUIREMENTS FOR AUTHORIZATION OF STATE HAZARDOUS WASTE PROGRAMS Requirements for Final Authorization § 271.11 Requirements for transporters of hazardous wastes. (a) The State...

  13. 78 FR 28987 - Revisions to Transportation Safety Requirements and Harmonization With International Atomic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-16

    ... Transportation Requirements; Establishing Quality Assurance Programs for Packaging Used in Transport of... would make the regulation of quality assurance programs more efficient by allowing changes that do not change quality assurance approval holder commitments to be made without prior NRC approval, and extending...

  14. Solar power satellite. System definition study. Part 1, volume 4: SPS transportation system requirements. [spacecraft propulsion

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The best estimates of space transportation requirements for cargo launch vehicles, personnel launch carriers, high thrust orbit transfer, and electric orbit transfer systems are discussed, along with the rationale for each.

  15. 77 FR 17394 - Hazardous Materials: Approval and Communication Requirements for the Safe Transportation of Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-26

    ... Communication Requirements for the Safe Transportation of Air Bag Inflators, Air Bag Modules, and Seat-Belt... Regulations applicable to air bag inflators, air bag modules, and seat-belt pretensioners. The proposed... classified as a [[Page 17395

  16. 49 CFR 174.82 - General requirements for the handling of placarded rail cars, transport vehicles, freight...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false General requirements for the handling of placarded rail cars, transport vehicles, freight containers, and bulk packages. 174.82 Section 174.82 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS...

  17. 49 CFR 174.82 - General requirements for the handling of placarded rail cars, transport vehicles, freight...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false General requirements for the handling of placarded rail cars, transport vehicles, freight containers, and bulk packages. 174.82 Section 174.82 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS...

  18. The Arabidopsis Golgi-localized GDP-L-fucose transporter is required for plant development

    DOE PAGES

    Rautengarten, Carsten; Ebert, Berit; Liu, Lifeng; ...

    2016-07-06

    Nucleotide sugar transport across Golgi membranes is essential for the luminal biosynthesis of glycan structures. Here we identify GDP-fucose transporter 1 (GFT1), an Arabidopsis nucleotide sugar transporter that translocates GDP-L-fucose into the Golgi lumen. Using proteo-liposome-based transport assays, we show that GFT preferentially transports GDP-L-fucose over other nucleotide sugars in vitro, while GFT1-silenced plants are almost devoid of L-fucose in cell wall-derived xyloglucan and rhamnogalacturonan II. Furthermore, these lines display reduced L-fucose content in N-glycan structures accompanied by severe developmental growth defects. We conclude that GFT1 is the major nucleotide sugar transporter for import of GDP-L-fucose into the Golgi andmore » is required for proper plant growth and development.« less

  19. The Arabidopsis Golgi-localized GDP-L-fucose transporter is required for plant development

    SciTech Connect

    Rautengarten, Carsten; Ebert, Berit; Liu, Lifeng

    Nucleotide sugar transport across Golgi membranes is essential for the luminal biosynthesis of glycan structures. Here we identify GDP-fucose transporter 1 (GFT1), an Arabidopsis nucleotide sugar transporter that translocates GDP-L-fucose into the Golgi lumen. Using proteo-liposome-based transport assays, we show that GFT preferentially transports GDP-L-fucose over other nucleotide sugars in vitro, while GFT1-silenced plants are almost devoid of L-fucose in cell wall-derived xyloglucan and rhamnogalacturonan II. Furthermore, these lines display reduced L-fucose content in N-glycan structures accompanied by severe developmental growth defects. We conclude that GFT1 is the major nucleotide sugar transporter for import of GDP-L-fucose into the Golgi andmore » is required for proper plant growth and development.« less

  20. The Arabidopsis Golgi-localized GDP-L-fucose transporter is required for plant development

    PubMed Central

    Rautengarten, Carsten; Ebert, Berit; Liu, Lifeng; Stonebloom, Solomon; Smith-Moritz, Andreia M.; Pauly, Markus; Orellana, Ariel; Scheller, Henrik Vibe; Heazlewood, Joshua L.

    2016-01-01

    Nucleotide sugar transport across Golgi membranes is essential for the luminal biosynthesis of glycan structures. Here we identify GDP-fucose transporter 1 (GFT1), an Arabidopsis nucleotide sugar transporter that translocates GDP-L-fucose into the Golgi lumen. Using proteo-liposome-based transport assays, we show that GFT preferentially transports GDP-L-fucose over other nucleotide sugars in vitro, while GFT1-silenced plants are almost devoid of L-fucose in cell wall-derived xyloglucan and rhamnogalacturonan II. Furthermore, these lines display reduced L-fucose content in N-glycan structures accompanied by severe developmental growth defects. We conclude that GFT1 is the major nucleotide sugar transporter for import of GDP-L-fucose into the Golgi and is required for proper plant growth and development. PMID:27381418

  1. The Arabidopsis Golgi-localized GDP-L-fucose transporter is required for plant development.

    PubMed

    Rautengarten, Carsten; Ebert, Berit; Liu, Lifeng; Stonebloom, Solomon; Smith-Moritz, Andreia M; Pauly, Markus; Orellana, Ariel; Scheller, Henrik Vibe; Heazlewood, Joshua L

    2016-07-06

    Nucleotide sugar transport across Golgi membranes is essential for the luminal biosynthesis of glycan structures. Here we identify GDP-fucose transporter 1 (GFT1), an Arabidopsis nucleotide sugar transporter that translocates GDP-L-fucose into the Golgi lumen. Using proteo-liposome-based transport assays, we show that GFT preferentially transports GDP-L-fucose over other nucleotide sugars in vitro, while GFT1-silenced plants are almost devoid of L-fucose in cell wall-derived xyloglucan and rhamnogalacturonan II. Furthermore, these lines display reduced L-fucose content in N-glycan structures accompanied by severe developmental growth defects. We conclude that GFT1 is the major nucleotide sugar transporter for import of GDP-L-fucose into the Golgi and is required for proper plant growth and development.

  2. 78 FR 45880 - Hazardous Materials: Approval and Communication Requirements for the Safe Transportation of Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-30

    ... Communication Requirements for the Safe Transportation of Air Bag Inflators, Air Bag Modules, and Seat-Belt... Materials Regulations applicable to air bag inflators, air bag modules, and seat-belt pretensioners. The... amending the current approval and documentation requirements for a material classified as a UN3268 air bag...

  3. Definition of display/control requirements for assault transport night/adverse weather capability

    NASA Technical Reports Server (NTRS)

    Milelli, R. J.; Mowery, G. W.; Pontelandolfo, C.

    1982-01-01

    A Helicopter Night Vision System was developed to improve low-altitude night and/or adverse weather assult transport capabilities. Man-in-the-loop simulation experiments were performed to define the minimum display and control requirements for the assult transport mission and investigate forward looking infrared sensor requirements, along with alternative displays such as panel mounted displays (PMD) helmet mounted displays (HMD), and integrated control display units. Also explored were navigation requirements, pilot/copilot interaction, and overall cockpit arrangement. Pilot use of an HMD and copilot use of a PMD appear as both the preferred and most effective night navigation combination.

  4. Surface transportation weather decision support requirements : operational concept description : advanced-integrated decision support using weather information for surface transportation decisions makers : draft version 2.0

    DOT National Transportation Integrated Search

    2000-07-14

    This is a draft document for the Surface Transportation Weather Decision Support Requirements (STWDSR) project. The STWDSR project is being conducted for the FHWAs Office of Transportation Operations (HOTO) Road Weather Management Program by Mitre...

  5. Accurate Black Hole Spin Measurements using ABC

    NASA Astrophysics Data System (ADS)

    Connolly, Andrew

    time. In particular, a class of methods col- lectively called Approximate Bayesian Computation (ABC) is capable of exploiting the fact that it is possible to simulate instrumental effects to a high degree of accuracy in order to build reliable statistical models incorporating pile-up and related effects. With the loss of the Hitomi spacecraft, it is more important than ever to make full use of the data we collect with current instruments. We propose an ambitious program to estimate the spins of 13 black holes in X-ray binaries using observations with XMMNewton s EPIC MOS and pn, Suzaku s XIS and Chandra s ACIS and HETG instruments. We will build a general framework for dealing with pile-up in spectral modeling using ABC and refine current instrumental simulators for inclusion in this framework. Coupled with state-of-the- art sampling methods, this will allow us to take advantage of dozens of observations in the archives of all three instruments. We will be able to estimate spins to much bet- ter accuracy than ever before and test current models for black hole formation as well as jet launching mechanisms. The program will deliver a considerable legacy, because the statistical and methodological framework will be general. Application to other instruments suffering from photon pile-up, e.g. Swift/XRT, Fermi/GBM, ASCA/SIS, and GALEX, will only require is a model capable of simulating the relevant instrumental effects. This will enable other science cases beyond that proposed here which rely on precise spectral measurements or cases where pile-up cannot be avoided, e.g. high-precision radius measurements in neutron stars, understanding X-ray dust scattering, and stellar evolution studies of globular clusters.

  6. Space transportation nodes assumptions and requirements: Lunar base systems study task 2.1

    NASA Technical Reports Server (NTRS)

    Kahn, Taher Ali; Simonds, Charles H.; Stump, William R.

    1988-01-01

    The Space Transportation Nodes Assumptions and Requirements task was performed as part of the Advanced Space Transportation Support Contract, a NASA Johnson Space Center (JSC) study intended to provide planning for a Lunar Base near the year 2000. The original task statement has been revised to satisfy the following queries: (1) What vehicles are to be processed at the transportation node; (2) What is the flow of activities involved in a vehicle passing through the node; and (3) What node support resources are necessary to support a lunar scenario traffic model composed of a mix of vehicles in an active flight schedule. The Lunar Base Systems Study is concentrating on the initial years of the Phase 2 Lunar Base Scenario. The study will develop the first five years of that phase in order to define the transportation and surface systems (including mass, volumes, power requirements, and designs).

  7. Safety policy and requirements for payloads using the space transportation system

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The safety policy and requirements are established applicable to the Space Transportation System (STS) payloads and their ground support equipment (GSE). The requirements are intended to protect flight and ground personnel, the STS, other payloads, GSE, the general public, public-private property, and the environment from payload-related hazards. The technical and system safety requirements applicable to STS payloads (including payload-provided ground and flight supports systems) during ground and flight operations are contained.

  8. Cyclin A-mediated inhibition of intra-Golgi transport requires p34cdc2.

    PubMed

    Mackay, D; Kieckbusch, R; Adamczewski, J; Warren, G

    1993-12-28

    An in vitro assay was used to study the role of p34cdc2 in cyclin A-mediated vesicular transport inhibition. It was shown that the S-phase kinase p33cdk2 reduced the effect of cyclin A on transport assays performed with sHeLa cytosol, even though histone kinase was strongly activated. Also, transport with FT210 cytosol (which is temperature-sensitive for p34cdc2) was inhibited by cyclin A only at the permissive temperature. However, the phosphatase inhibitor microcystin inhibited transport without any requirement for p34cdc2 activity. These results show that transport is inhibited by cyclin A via p34cdc2, and also by another kinase, possibly downstream of p34cdc2.

  9. Capital requirements for the transportation of energy materials based on PIES Scenario estimates

    SciTech Connect

    Gezen, A.; Kendrick, M.J.; Khan, S.S.

    In May 1978, Transportation and Economic Research Associates (TERA), Inc. completed a study in which information and methodologies were developed for the determination of capital requirements in the transportation of energy materials. This work was designed to aid EIA in the analysis of PIES solutions. The work consisted of the development of five algorithms which are used to estimate transportation-investment requirements associated with energy commodities and transportation modes. For the purpose of this analysis, TERA was provided with three PIES-solution scenarios for 1985. These are: Scenario A which assumes a high domestic economic rate of growth along with its correspondingmore » high demand for petroleum, as well as a high domestic supply of petroleum; Scenario C which assumes a medium level of economic growth and petroleum demand and supply; and Scenario E which assumes a low level of economic growth and domestic demand and supply for petroleum. Two PIES-related outputs used in TERA's analysis are the ''COOKIE'' reports which present activity summaries by region and ''PERUSE'' printouts of solution files which give interregional flows by energy material. Only the transportation of four energy materials, crude oil, petroleum products, natural gas, and coal is considered. In estimating the capital costs of new or expanded capacity for the transportation of these materials, three transportation modes were examined: pipelines, water carriers (inland barge and deep draft vessels), and railroads. (MCW)« less

  10. Regulation of the ATPase activity of ABCE1 from Pyrococcus abyssi by Fe-S cluster status and Mg²⁺: implication for ribosomal function.

    PubMed

    Sims, Lynn M; Igarashi, Robert Y

    2012-08-15

    Ribosomal function is dependent on multiple proteins. The ABCE1 ATPase, a unique ABC superfamily member that bears two Fe₄S₄ clusters, is crucial for ribosomal biogenesis and recycling. Here, the ATPase activity of the Pyrococcus abyssi ABCE1 (PabABCE1) was studied using both apo- (without reconstituted Fe-S clusters) and holo- (with full complement of Fe-S clusters reconstituted post-purification) forms, and is shown to be jointly regulated by the status of Fe-S clusters and Mg²⁺. Typically ATPases require Mg²⁺, as is true for PabABCE1, but Mg²⁺ also acts as a negative allosteric effector that modulates ATP affinity of PabABCE1. Physiological [Mg²⁺] inhibits the PabABCE1 ATPase (K(i) of ∼1 μM) for both apo- and holo-PabABCE1. Comparative kinetic analysis of Mg²⁺ inhibition shows differences in degree of allosteric regulation between the apo- and holo-PabABCE1 where the apparent ATP K(m) of apo-PabABCE1 increases >30-fold from ∼30 μM to over 1 mM with M²⁺. This effect would significantly convert the ATPase activity of PabABCE1 from being independent of cellular energy charge (φ) to being dependent on φ with cellular [Mg²⁺]. These findings uncover intricate overlapping effects by both [Mg²⁺] and the status of Fe-S clusters that regulate ABCE1's ATPase activity with implications to ribosomal function. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Do Pediatric Teams Affect Outcomes of Injured Children Requiring Inter-hospital Transport?

    PubMed

    Calhoun, Amanda; Keller, Martin; Shi, Junxin; Brancato, Celeste; Donovan, Kathy; Kraus, Diana; Leonard, Julie C

    2017-01-01

    Studies show that pediatric trauma centers produce better outcomes and reduced mortality for injured children. Yet, most children do not have timely access to a pediatric trauma center and require stabilization locally with subsequent transfer. Investigators have demonstrated that pediatric transport teams (PTT) improve outcomes for critically ill children; however, these studies did not differentiate outcomes for injured children. It may be that moderate to severely injured children actually fare worse with PTT due to slower transport times inherent to their remote locations and thus delays in important interventions. The purpose of this study was to determine if outcomes for injured children are affected by use of PTT for inter-hospital transfer. We conducted a retrospective chart review of 1,177 children transferred to a pediatric trauma center for injury care between March 1st, 2012 and December 31st, 2013. We compared children who were transported by PTT (ground/air) to those transported by ground advanced life support (ALS) and air critical care (ACC). We described patient characteristics and transport times. For PTT vs. ALS and ACC, we compared hospital length of stay (LOS), transport interventions and adverse events. 1,177 injured children were transferred by the following modes: 68% ALS, 13% ACC, 11% Ground PTT, and 9% Air PTT. Children transported by PTT were younger and had higher ISS and lower GCS scores. PTT had a longer total transport time, departure preparation time, and patient bedside time. After controlling for age, ISS, GCS, transport mode, distance, and time, we found no significant difference in LOS between PTT vs. ALS and ACC. A subgroup analysis of children with higher ISS scores demonstrated a 65% longer LOS for children transported by ACC vs. PTT. There were no differences between transport teams with regard to acidosis, hypocarbia or hypercarbia, or maintenance of tubes and lines. Children transported by PTT were younger and sicker (vs

  12. The ABC's of Learning in Infancy.

    ERIC Educational Resources Information Center

    Saunders, Minta M.

    Learning in infancy is based on activity, beginnings, and curiosity, the so-called ABC's. Earliest behavior consists of mass activity, the period from birth to 24 months of sensory-motor development which provides the foundation for all future learning. Adults must provide space, toys, and affectionate care to help infants proceed through…

  13. Calculus ABCs: A Gateway for Freshman Calculus

    ERIC Educational Resources Information Center

    Fulton, Scott R.

    2003-01-01

    This paper describes a gateway testing program designed to ensure that students acquire basic skills in freshman calculus. Students must demonstrate they have mastered standards for "Absolutely Basic Competency"--the Calculus ABCs--in order to pass the course with a grade of C or better. We describe the background, standards, and testing program.…

  14. 49 CFR 385.415 - What operational requirements apply to the transportation of a hazardous material for which a...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... material for which a permit is required? (a) Information that must be carried in the vehicle. During transportation, the following must be maintained in each commercial motor vehicle that transports a hazardous... are not sufficient to meet this requirement. (b)(1) Inspection of vehicle transporting Class 7...

  15. 78 FR 17781 - Transportation Worker Identification Credential (TWIC)-Reader Requirements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-22

    ...In this Notice of Proposed Rulemaking (NPRM), the Coast Guard proposes to require owners and operators of certain vessels and facilities regulated by the Coast Guard to use electronic readers designed to work with the Transportation Worker Identification Credential (TWIC) as an access control measure. This NPRM also proposes additional requirements associated with electronic TWIC readers, including recordkeeping requirements for those owners and operators required to use an electronic TWIC reader, and security plan amendments to incorporate TWIC requirements. The TWIC program, including the proposed TWIC reader requirements in this rule, is an important component of the Coast Guard's multi-layered system of access control requirements and other measures designed to enhance maritime security. This rulemaking action, once final, would build upon existing Coast Guard regulations designed to ensure that only individuals who hold a TWIC are granted unescorted access to secure areas at those locations. The Coast Guard has already promulgated regulations pursuant to the Maritime Transportation Security Act of 2002 (MTSA) that require mariners and other individuals to obtain a TWIC and present it for inspection by security personnel prior to gaining access to such secure areas. By requiring certain vessels and facilities to perform TWIC inspections using electronic TWIC readers, this rulemaking would further enhance security at those locations. This rulemaking would also implement the Security and Accountability For Every Port Act of 2006 electronic TWIC reader requirements.

  16. Inferring population history with DIY ABC: a user-friendly approach to approximate Bayesian computation.

    PubMed

    Cornuet, Jean-Marie; Santos, Filipe; Beaumont, Mark A; Robert, Christian P; Marin, Jean-Michel; Balding, David J; Guillemaud, Thomas; Estoup, Arnaud

    2008-12-01

    Genetic data obtained on population samples convey information about their evolutionary history. Inference methods can extract part of this information but they require sophisticated statistical techniques that have been made available to the biologist community (through computer programs) only for simple and standard situations typically involving a small number of samples. We propose here a computer program (DIY ABC) for inference based on approximate Bayesian computation (ABC), in which scenarios can be customized by the user to fit many complex situations involving any number of populations and samples. Such scenarios involve any combination of population divergences, admixtures and population size changes. DIY ABC can be used to compare competing scenarios, estimate parameters for one or more scenarios and compute bias and precision measures for a given scenario and known values of parameters (the current version applies to unlinked microsatellite data). This article describes key methods used in the program and provides its main features. The analysis of one simulated and one real dataset, both with complex evolutionary scenarios, illustrates the main possibilities of DIY ABC. The software DIY ABC is freely available at http://www.montpellier.inra.fr/CBGP/diyabc.

  17. Inferring population history with DIY ABC: a user-friendly approach to approximate Bayesian computation

    PubMed Central

    Cornuet, Jean-Marie; Santos, Filipe; Beaumont, Mark A.; Robert, Christian P.; Marin, Jean-Michel; Balding, David J.; Guillemaud, Thomas; Estoup, Arnaud

    2008-01-01

    Summary: Genetic data obtained on population samples convey information about their evolutionary history. Inference methods can extract part of this information but they require sophisticated statistical techniques that have been made available to the biologist community (through computer programs) only for simple and standard situations typically involving a small number of samples. We propose here a computer program (DIY ABC) for inference based on approximate Bayesian computation (ABC), in which scenarios can be customized by the user to fit many complex situations involving any number of populations and samples. Such scenarios involve any combination of population divergences, admixtures and population size changes. DIY ABC can be used to compare competing scenarios, estimate parameters for one or more scenarios and compute bias and precision measures for a given scenario and known values of parameters (the current version applies to unlinked microsatellite data). This article describes key methods used in the program and provides its main features. The analysis of one simulated and one real dataset, both with complex evolutionary scenarios, illustrates the main possibilities of DIY ABC. Availability: The software DIY ABC is freely available at http://www.montpellier.inra.fr/CBGP/diyabc. Contact: j.cornuet@imperial.ac.uk Supplementary information: Supplementary data are also available at http://www.montpellier.inra.fr/CBGP/diyabc PMID:18842597

  18. An example of requirements for Advanced Subsonic Civil Transport (ASCT) flight control system using structured techniques

    NASA Technical Reports Server (NTRS)

    Mclees, Robert E.; Cohen, Gerald C.

    1991-01-01

    The requirements are presented for an Advanced Subsonic Civil Transport (ASCT) flight control system generated using structured techniques. The requirements definition starts from initially performing a mission analysis to identify the high level control system requirements and functions necessary to satisfy the mission flight. The result of the study is an example set of control system requirements partially represented using a derivative of Yourdon's structured techniques. Also provided is a research focus for studying structured design methodologies and in particular design-for-validation philosophies.

  19. [Biological characteristics of an enteroinvasive Escherichia coli strain with tatABC deletion].

    PubMed

    Gong, Zhaolong; Ye, Changyun; Liu, Xiaobing; Zhang, Min; Zhuo, Qin

    2013-05-04

    To study the relationship between twin-arginine translocation system (Tat) system with the biological characteristics of enteroinvasive Escherichia coli (EIEC). Through homologous recombination, we constructed EIEC's tatABC gene deletion strain and complementary strain, and explored their impact on bacterial form, substrate transport function as well as on HeLa cells and guinea pig's corneal invasion force. The tatABC gene deletion strain had apparent changes in bacterial form, loss of substrate transporter function, and significant weakened bacterial invasion force (the number of the deletion strain invading into HeLa cells was decreased significantly, and the ability of its corneal lesion capacity of the guinea pig was significantly weakened), while the complementary strain was similar to the wild strain in the above respects. EIEC's Tat protein transport system is closely related with the biological characteristics of EIEC.

  20. Synthesis from Design Requirements of a Hybrid System for Transport Aircraft Longitudinal Control. Volume 2

    NASA Technical Reports Server (NTRS)

    Hynes, Charles S.; Hardy, Gordon H.; Sherry, Lance

    2007-01-01

    Volume I of this report presents a new method for synthesizing hybrid systems directly from desi gn requirements, and applies the method to design of a hybrid system for longitudinal control of transport aircraft. The resulting system satisfies general requirement for safety and effectiveness specified a priori, enabling formal validation to be achieved. Volume II contains seven appendices intended to make the report accessible to readers with backgrounds in human factors, flight dynamics and control, and formal logic. Major design goals are (1) system design integrity based on proof of correctness at the design level, (2) significant simplification and cost reduction in system development and certification, and (3) improved operational efficiency, with significant alleviation of human-factors problems encountered by pilots in current transport aircraft. This report provides for the first time a firm technical basis for criteria governing design and certification of avionic systems for transport aircraft. It should be of primary interest to designers of next-generation avionic systems.

  1. 9 CFR 11.40 - Prohibitions and requirements concerning persons involved in transportation of certain horses.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Prohibitions and requirements concerning persons involved in transportation of certain horses. 11.40 Section 11.40 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE HORSE...

  2. 75 FR 63 - Hazardous Materials: Revision to Requirements for the Transportation of Batteries and Battery...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-04

    ... 2137-AE54 Hazardous Materials: Revision to Requirements for the Transportation of Batteries and Battery... batteries and battery-powered devices. This final rule corrects several errors in the January 14, 2009 final... batteries and battery-powered devices. This final rule corrects several errors in the final rule. Because...

  3. 32 CFR 861.4 - DOD air transportation quality and safety requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... programs and business practices that not only ensure good service but also enhance the safety, operational...) “Equivalent to the services sought by DOD” means service offered to qualify for DOD approval must be... § 861.4 DOD air transportation quality and safety requirements. (a) General. The DOD, as a customer of...

  4. LC-MS/MS Based Quantitation of ABC and SLC Transporter Proteins in Plasma Membranes of Cultured Primary Human Retinal Pigment Epithelium Cells and Immortalized ARPE19 Cell Line.

    PubMed

    Pelkonen, Laura; Sato, Kazuki; Reinisalo, Mika; Kidron, Heidi; Tachikawa, Masanori; Watanabe, Michitoshi; Uchida, Yasuo; Urtti, Arto; Terasaki, Tetsuya

    2017-03-06

    The retinal pigment epithelium (RPE) forms the outer blood-retinal barrier between neural retina and choroid. The RPE has several important vision supporting functions, such as transport mechanisms that may also modify pharmacokinetics in the posterior eye segment. Expression of plasma membrane transporters in the RPE cells has not been quantitated. The aim of this study was to characterize and compare transporter protein expression in the ARPE19 cell line and hfRPE (human fetal RPE) cells by using quantitative targeted absolute proteomics (QTAP). Among 41 studied transporters, 16 proteins were expressed in hfRPE and 13 in ARPE19 cells. MRP1, MRP5, GLUT1, 4F2hc, TAUT, CAT1, LAT1, and MATE1 proteins were detected in both cell lines within 4-fold differences. MPR7, OAT2 and RFC1 were detected in the hfRPE cells, but their expression levels were below the limit of quantification in ARPE19 cells. PCFT was detected in both studied cell lines, but the expression was over 4-fold higher in hfRPE cells. MCT1, MCT4, MRP4, and Na + /K + ATPase were upregulated in the ARPE19 cell line showing over 4-fold differences in the quantitative expression values. Expression levels of 25 transporters were below the limit of quantification in both cell models. In conclusion, we present the first systematic and quantitative study on transporter protein expression in the plasma membranes of ARPE19 and hfRPE cells. Overall, transporter expression in the ARPE19 and hfRPE cells correlated well and the absolute expression levels were similar, but not identical. The presented quantitative expression levels could be a useful basis for further studies on drug permeation in the outer blood-retinal barrier.

  5. Serum albumin promotes ATP-binding cassette transporter-dependent sterol uptake in yeast.

    PubMed

    Marek, Magdalena; Silvestro, Daniele; Fredslund, Maria D; Andersen, Tonni G; Pomorski, Thomas G

    2014-12-01

    Sterol uptake in fungi is a multistep process that involves interaction between external sterols and the cell wall, incorporation of sterol molecules into the plasma membrane, and subsequent integration into intracellular membranes for turnover. ATP-binding cassette (ABC) transporters have been implicated in sterol uptake, but key features of their activity remain to be elucidated. Here, we apply fluorescent cholesterol (NBD-cholesterol) to monitor sterol uptake under anaerobic and aerobic conditions in two fungal species, Candida glabrata (Cg) and Saccharomyces cerevisiae (Sc). We found that in both fungal species, ABC transporter-dependent uptake of cholesterol under anaerobic conditions and in mutants lacking HEM1 gene is promoted in the presence of the serum protein albumin that is able to bind the sterol molecule. Furthermore, the C. glabrata ABC transporter CgAus1p expressed in S. cerevisiae requires the presence of serum or albumin for efficient cholesterol uptake. These results suggest that albumin can serve as sterol donor in ABC transporter-dependent sterol uptake, a process potentially important for growth of C. glabrata inside infected humans. © 2014 The Authors. FEMS Yeast Research published by John Wiley & Sons Ltd on behalf of Federation of European Microbiological Societies.

  6. Astrocyte-neuron lactate transport is required for long-term memory formation.

    PubMed

    Suzuki, Akinobu; Stern, Sarah A; Bozdagi, Ozlem; Huntley, George W; Walker, Ruth H; Magistretti, Pierre J; Alberini, Cristina M

    2011-03-04

    We report that, in the rat hippocampus, learning leads to a significant increase in extracellular lactate levels that derive from glycogen, an energy reserve selectively localized in astrocytes. Astrocytic glycogen breakdown and lactate release are essential for long-term but not short-term memory formation, and for the maintenance of long-term potentiation (LTP) of synaptic strength elicited in vivo. Disrupting the expression of the astrocytic lactate transporters monocarboxylate transporter 4 (MCT4) or MCT1 causes amnesia, which, like LTP impairment, is rescued by L-lactate but not equicaloric glucose. Disrupting the expression of the neuronal lactate transporter MCT2 also leads to amnesia that is unaffected by either L-lactate or glucose, suggesting that lactate import into neurons is necessary for long-term memory. Glycogenolysis and astrocytic lactate transporters are also critical for the induction of molecular changes required for memory formation, including the induction of phospho-CREB, Arc, and phospho-cofilin. We conclude that astrocyte-neuron lactate transport is required for long-term memory formation. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Astrocyte-neuron lactate transport is required for long-term memory formation

    PubMed Central

    Suzuki, Akinobu; Stern, Sarah A.; Bozdagi, Ozlem; Huntley, George W.; Walker, Ruth H.; Magistretti, Pierre J.; Alberini, Cristina M.

    2011-01-01

    SUMMARY We report that in the rat hippocampus learning leads to a significant increase in extracellular lactate levels, which derive from glycogen, an energy reserve selectively localized in astrocytes. Astrocytic glycogen breakdown and lactate release are essential for long-term but not short-term memory formation, and for the maintenance of long-term potentiation (LTP) of synaptic strength elicited in-vivo. Disrupting the expression of the astrocytic lactate transporters monocarboxylate transporter 4 (MCT4) or MCT1 causes amnesia, which, like LTP impairment, is rescued by lactate but not equicaloric glucose. Disrupting the expression of the neuronal lactate transporter MCT2 also leads to amnesia that is unaffected by either L-lactate or glucose, suggesting that lactate import into neurons is necessary for long-term memory. Glycogenolysis and astrocytic lactate transporters are also critical for the induction of molecular changes required for memory formation, including the induction of phospho-CREB, Arc and phospho-cofilin. We conclude that astrocyte-neuron lactate transport is required for long-term memory formation. PMID:21376239

  8. 40 CFR 80.350 - What alternative sulfur standards and requirements apply to importers who transport gasoline by...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... requirements apply to importers who transport gasoline by truck? 80.350 Section 80.350 Protection of... ADDITIVES Gasoline Sulfur Sampling, Testing and Retention Requirements for Refiners and Importers § 80.350 What alternative sulfur standards and requirements apply to importers who transport gasoline by truck...

  9. 40 CFR 80.350 - What alternative sulfur standards and requirements apply to importers who transport gasoline by...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... requirements apply to importers who transport gasoline by truck? 80.350 Section 80.350 Protection of... ADDITIVES Gasoline Sulfur Sampling, Testing and Retention Requirements for Refiners and Importers § 80.350 What alternative sulfur standards and requirements apply to importers who transport gasoline by truck...

  10. 40 CFR 80.350 - What alternative sulfur standards and requirements apply to importers who transport gasoline by...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... requirements apply to importers who transport gasoline by truck? 80.350 Section 80.350 Protection of... ADDITIVES Gasoline Sulfur Sampling, Testing and Retention Requirements for Refiners and Importers § 80.350 What alternative sulfur standards and requirements apply to importers who transport gasoline by truck...

  11. 40 CFR 80.350 - What alternative sulfur standards and requirements apply to importers who transport gasoline by...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... requirements apply to importers who transport gasoline by truck? 80.350 Section 80.350 Protection of... ADDITIVES Gasoline Sulfur Sampling, Testing and Retention Requirements for Refiners and Importers § 80.350 What alternative sulfur standards and requirements apply to importers who transport gasoline by truck...

  12. 40 CFR 80.350 - What alternative sulfur standards and requirements apply to importers who transport gasoline by...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... requirements apply to importers who transport gasoline by truck? 80.350 Section 80.350 Protection of... ADDITIVES Gasoline Sulfur Sampling, Testing and Retention Requirements for Refiners and Importers § 80.350 What alternative sulfur standards and requirements apply to importers who transport gasoline by truck...

  13. Loss of plastoglobule kinases ABC1K1 and ABC1K3 causes conditional degreening, modified prenyl-lipids, and recruitment of the jasmonic acid pathway

    USDA-ARS?s Scientific Manuscript database

    Plastoglobules (PGs) are plastid lipid-protein particles. This study examines the function of PG-localized kinases ABC1K1 and ABC1K3 in Arabidopsis thaliana. Several lines of evidence suggested that ABC1K1 and ABC1K3 form a protein complex. Null mutants for both genes (abc1k1 and abc1k3) and the dou...

  14. Analysis of operational requirements for medium density air transportation. Volume 1: Summary

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The medium density air travel market was studied to determine the aircraft design and operational requirements. The impact of operational characteristics on the air travel system and the economic viability of the study aircraft were also evaluated. Medium density is defined in terms of numbers of people transported (20 to 500 passengers per day on round trip routes), and frequency of service ( a minumium of two and maximum of eight round trips per day) for 10 regional carriers. The operational characteristics of aircraft best suited to serve the medium density air transportation market are determined and a basepoint aircraft is designed from which tradeoff studies and parametric variations could be conducted. The impact of selected aircraft on the medium density market, economics, and operations is ascertained. Research and technology objectives for future programs in medium density air transportation are identified and ranked.

  15. Phylodynamic Inference with Kernel ABC and Its Application to HIV Epidemiology.

    PubMed

    Poon, Art F Y

    2015-09-01

    The shapes of phylogenetic trees relating virus populations are determined by the adaptation of viruses within each host, and by the transmission of viruses among hosts. Phylodynamic inference attempts to reverse this flow of information, estimating parameters of these processes from the shape of a virus phylogeny reconstructed from a sample of genetic sequences from the epidemic. A key challenge to phylodynamic inference is quantifying the similarity between two trees in an efficient and comprehensive way. In this study, I demonstrate that a new distance measure, based on a subset tree kernel function from computational linguistics, confers a significant improvement over previous measures of tree shape for classifying trees generated under different epidemiological scenarios. Next, I incorporate this kernel-based distance measure into an approximate Bayesian computation (ABC) framework for phylodynamic inference. ABC bypasses the need for an analytical solution of model likelihood, as it only requires the ability to simulate data from the model. I validate this "kernel-ABC" method for phylodynamic inference by estimating parameters from data simulated under a simple epidemiological model. Results indicate that kernel-ABC attained greater accuracy for parameters associated with virus transmission than leading software on the same data sets. Finally, I apply the kernel-ABC framework to study a recent outbreak of a recombinant HIV subtype in China. Kernel-ABC provides a versatile framework for phylodynamic inference because it can fit a broader range of models than methods that rely on the computation of exact likelihoods. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  16. PKCzeta is required for microtubule-based motility of vesicles containing the ntcp transporter.

    PubMed

    Sarkar, Souvik; Bananis, Eustratios; Nath, Sangeeta; Anwer, M Sawkat; Wolkoff, Allan W; Murray, John W

    2006-08-01

    Intracellular trafficking regulates the abundance and therefore activity of transporters present at the plasma membrane. The transporter, Na+-taurocholate co-transporting polypeptide (ntcp), is increased at the plasma membrane upon treatment of cells with cAMP, for which microtubules (MTs) are required and the PI3K pathway and PKCzeta have been implicated. However, trafficking of ntcp on MTs has not been demonstrated directly and the regulation and intracellular localization of ntcp is not well understood. Here, we utilize in vitro and whole-cell immunofluorescence microscopy assays to demonstrate that ntcp is present on intracellular vesicles that bind MTs and move bidirectionally, using kinesin-1 and dynein. These vesicles co-localize with markers for recycling endosomes and early but not late endosomes. They frequently undergo fission, providing a mechanism for the exclusion of ntcp from late endosomes. PI(3,4,5)P3 activates PKCzeta and enhances motility of the ntcp vesicles and overcomes the partial inhibition produced by a PI3-kinase inhibitor. Specific inhibition of PKCzeta blocks the motility of ntcp-containing vesicles but has no effect on late vesicles as shown both in vitro and in living cells transfected with ntcp-GFP. These data indicate that PKCzeta is required specifically for the intracellular movement of vesicles that contain the ntcp transporter.

  17. Auxin transport and response requirements for root hydrotropism differ between plant species.

    PubMed

    Nakajima, Yusuke; Nara, Yoshitaka; Kobayashi, Akie; Sugita, Tomoki; Miyazawa, Yutaka; Fujii, Nobuharu; Takahashi, Hideyuki

    2017-06-15

    The direction of auxin transport changes in gravistimulated roots, causing auxin accumulation in the lower side of horizontally reoriented roots. This study found that auxin was similarly involved in hydrotropism and gravitropism in rice and pea roots, but hydrotropism in Lotus japonicus roots was independent of both auxin transport and response. Application of either auxin transport inhibitors or an auxin response inhibitor decreased both hydrotropism and gravitropism in rice roots, and reduced hydrotropism in pea roots. However, Lotus roots treated with these inhibitors showed reduced gravitropism but an unaltered or an enhanced hydrotropic response. Inhibiting auxin biosynthesis substantially reduced both tropisms in rice and Lotus roots. Removing the final 0.2 mm (including the root cap) from the root tip inhibited gravitropism but not hydrotropism in rice seedling roots. These results suggested that modes of auxin involvement in hydrotropism differed between plant species. In rice roots, although auxin transport and responses were required for both gravitropism and hydrotropism, the root cap was involved in the auxin regulation of gravitropism but not hydrotropism. Hydrotropism in Lotus roots, however, may be regulated by a novel mechanism that is independent of both auxin transport and the TIR1/AFBs auxin response pathway. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  18. 49 CFR 174.82 - General requirements for the handling of placarded rail cars, transport vehicles, freight...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... rail cars, transport vehicles, freight containers, and bulk packages. 174.82 Section 174.82... Placarded Rail Cars, Transport Vehicles and Freight Containers § 174.82 General requirements for the handling of placarded rail cars, transport vehicles, freight containers, and bulk packages. (a) Unless...

  19. 36 CFR 13.1128 - Is a permit required to transport passengers between Bartlett Cove and Gustavus?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... transport passengers between Bartlett Cove and Gustavus? 13.1128 Section 13.1128 Parks, Forests, and Public... Regulations-Glacier Bay National Park and Preserve Bartlett Cove § 13.1128 Is a permit required to transport passengers between Bartlett Cove and Gustavus? Commercial transport of passengers between Bartlett Cove and...

  20. Technology requirements for future Earth-to-geosynchronous orbit transportation systems. Volume 2: Technical results

    NASA Technical Reports Server (NTRS)

    Caluori, V. A.

    1980-01-01

    Technologies either critical to performance of offering cost advantages compared to the investment required to bring them to usable confidence levels are identified. A total transportation system is used as an evaluation yardstick. Vehicles included in the system are a single stage to orbit launch vehicle used in a priority cargo role, a matching orbit transfer vehicle, a heavy lift launch vehicle with a low Earth orbit delivery capability of 226, 575 kg, and a matching solar electric cargo orbit transfer vehicle. The system and its reference technology level are consistent with an initial operational capability in 1990. The 15 year mission scenario is based on early space industrialization leading to the deployment of large systems such as power satellites. Life cycle cost benefits in discounted and undiscounted dollars for each vehicle, technology advancement, and the integrated transportation system are calculated. A preliminary functional analysis was made of the operational support requirements for ground based and space based chemical propulsion orbit transfer vehicles.

  1. Phase behavior of model ABC triblock copolymers

    NASA Astrophysics Data System (ADS)

    Chatterjee, Joon

    The phase behavior of poly(isoprene-b-styrene- b-ethylene oxide) (ISO), a model ABC triblock copolymer has been studied. This class of materials exhibit self-assembly, forming a large array of ordered morphologies at length scales of 5-100 nm. The formation of stable three-dimensionally continuous network morphologies is of special interest in this study. Since these nanostructures considerably impact the material properties, fundamental knowledge for designing ABC systems have high technological importance for realizing applications in the areas of nanofabrication, nanoporous media, separation membranes, drug delivery and high surface area catalysts. A comprehensive framework was developed to describe the phase behavior of the ISO triblock copolymers at weak to intermediate segregation strengths spanning a wide range of composition. Phases were characterized through a combination of characterization techniques, including small angle x-ray scattering, dynamic mechanical spectroscopy, transmission electron microscopy, and birefringence measurements. Combined with previous investigations on ISO, six different stable ordered state symmetries have been identified: lamellae (LAM), Fddd orthorhombic network (O70), double gyroid (Q230), alternating gyroid (Q214), hexagonal (HEX), and body-centered cubic (BCC). The phase map was found to be somewhat asymmetric around the fI = fO isopleth. This work provides a guide for theoretical studies and gives insight into the intricate effects of various parameters on the self-assembly of ABC triblock copolymers. Experimental SAXS data evaluated with a simple scattering intensity model show that local mixing varies continuously across the phase map between states of two- and three-domain segregation. Strategies of blending homopolymers with ISO triblock copolymer were employed for studying the swelling properties of a lamellar state. Results demonstrate that lamellar domains swell or shrink depending upon the type of homopolymer that

  2. Measurements Required to Understand the Lunar Dust Environment and Transport Mechanism

    NASA Technical Reports Server (NTRS)

    Spann, James F., Jr.; Abbas, Mian

    2006-01-01

    Going back to the lunar surface offers an opportunity to understand the dust environment and associated transport mechanisms. This talk will explore what measurements are required to understand and characterize the dust-plasma environment in which robotic and human activities will be conducted. The understanding gained with the measurements can be used to make informed decisions on engineering solutions and follow-on investigations. Particular focus will be placed on required measurements of the size, spatial and charge distribution of the suspended lunar regolith.

  3. Safety policy and requirements for payloads using the Space Transportation System (STS)

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The Space Transportation Operations (STO) safety policy is to minimize STO involvement in the payload and its GSE (ground support equipment) design process while maintaining the assurance of a safe operation. Requirements for assuring payload mission success are the responsibility of the payload organization and are beyond the scope of this document. The intent is to provide the overall safety policies and requirements while allowing for negotiation between the payload organization and the STO operator in the method of implementation of payload safety. This revision provides for a relaxation in the monitoring requirements for inhibits, allows the payload organization to pursue design options and reflects, additionally, some new requirements. As of the issue date of this NHB, payloads which have completed the formal safety assessment reviews of their preliminary design on the basis of the May 1979 issue will be reassessed for compliance with the above changes.

  4. 40 CFR 80.1641 - Alternative sulfur standards and requirements that apply to importers who transport gasoline by...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... requirements that apply to importers who transport gasoline by truck. 80.1641 Section 80.1641 Protection of... ADDITIVES Gasoline Sulfur § 80.1641 Alternative sulfur standards and requirements that apply to importers who transport gasoline by truck. Importers who import gasoline into the United States by truck may...

  5. 40 CFR 52.2141 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of sulfur dioxide? 52.2141 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of sulfur dioxide? (a) The...

  6. 40 CFR 52.2540 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 5 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2540 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  7. 40 CFR 52.1930 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1930 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a) The...

  8. 40 CFR 52.1084 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1084 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  9. 40 CFR 52.484 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.484 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  10. 40 CFR 52.1784 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1784 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  11. 40 CFR 52.2440 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 5 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2440 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  12. 40 CFR 52.1326 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1326 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  13. 40 CFR 52.1284 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1284 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a) The...

  14. 40 CFR 52.2040 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 5 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2040 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  15. 40 CFR 52.1584 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1584 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  16. 40 CFR 52.2283 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2283 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  17. 40 CFR 52.1084 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1084 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  18. 40 CFR 52.1584 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1584 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  19. 40 CFR 52.2240 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 5 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2240 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  20. 40 CFR 52.2283 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 5 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2283 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  1. 40 CFR 52.484 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.484 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  2. 40 CFR 52.484 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.484 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  3. 40 CFR 52.2140 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2140 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  4. 40 CFR 52.2240 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2240 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  5. 40 CFR 52.2240 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2240 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  6. 40 CFR 52.484 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.484 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  7. 40 CFR 52.2240 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2240 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  8. 40 CFR 52.1584 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1584 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  9. 40 CFR 52.2240 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 5 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2240 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  10. 40 CFR 52.1784 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1784 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  11. 40 CFR 52.1428 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1428 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a) The...

  12. 40 CFR 52.1684 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1684 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  13. 40 CFR 52.1186 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1186 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  14. 40 CFR 52.1326 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1326 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  15. 40 CFR 52.2140 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2140 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  16. 40 CFR 52.2140 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2140 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  17. 40 CFR 52.1428 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1428 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a) The...

  18. 40 CFR 52.2440 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 5 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2440 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  19. 40 CFR 52.2540 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2540 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  20. 40 CFR 52.1326 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1326 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  1. 40 CFR 52.1186 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1186 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  2. 40 CFR 52.2040 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2040 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  3. 40 CFR 52.1930 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1930 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a) The...

  4. 40 CFR 52.2140 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 5 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2140 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  5. 40 CFR 52.1284 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1284 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a) The...

  6. 40 CFR 52.1784 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1784 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  7. 40 CFR 52.2540 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 5 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2540 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  8. 40 CFR 52.1784 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1784 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  9. 40 CFR 52.1930 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1930 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a) The...

  10. 40 CFR 52.1784 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1784 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  11. 40 CFR 52.1084 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1084 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  12. 40 CFR 52.1186 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1186 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  13. 40 CFR 52.2283 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2283 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  14. 40 CFR 52.484 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.484 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  15. 40 CFR 52.2440 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2440 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  16. 40 CFR 52.2040 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 5 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2040 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  17. 40 CFR 52.1186 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1186 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  18. 40 CFR 52.1584 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1584 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  19. 40 CFR 52.1186 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1186 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  20. 40 CFR 52.1684 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1684 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  1. 40 CFR 52.2140 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 5 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2140 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  2. 40 CFR 52.1428 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1428 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a) The...

  3. 40 CFR 52.1684 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1684 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  4. 40 CFR 52.1684 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1684 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  5. 40 CFR 52.2283 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2283 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  6. 40 CFR 52.1284 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1284 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a) The...

  7. 40 CFR 52.2283 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 5 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2283 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  8. 40 CFR 52.1584 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1584 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  9. 40 CFR 52.2588 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of sulfur dioxide? 52.2588 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of sulfur dioxide? (a) The...

  10. 40 CFR 52.2041 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of sulfur dioxide? 52.2041 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of sulfur dioxide? (a) The...

  11. 40 CFR 52.2441 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of sulfur dioxide? 52.2441 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of sulfur dioxide? (a) The...

  12. 40 CFR 52.2541 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of sulfur dioxide? 52.2541 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of sulfur dioxide? (a) The...

  13. 40 CFR 52.2284 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of sulfur dioxide? 52.2284 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of sulfur dioxide? (a) The...

  14. 40 CFR 52.2241 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of sulfur dioxide? 52.2241 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of sulfur dioxide? (a) The...

  15. 30 CFR 1206.114 - What are my reporting requirements under an arm's-length transportation contract?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false What are my reporting requirements under an arm... VALUATION Federal Oil § 1206.114 What are my reporting requirements under an arm's-length transportation... submit arm's-length transportation contracts, production agreements, operating agreements, and related...

  16. 30 CFR 206.115 - What are my reporting requirements under a non-arm's-length transportation arrangement?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What are my reporting requirements under a non-arm's-length transportation arrangement? 206.115 Section 206.115 Mineral Resources MINERALS MANAGEMENT... What are my reporting requirements under a non-arm's-length transportation arrangement? (a) You or your...

  17. 30 CFR 1206.115 - What are my reporting requirements under a non-arm's-length transportation arrangement?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false What are my reporting requirements under a non-arm's-length transportation arrangement? 1206.115 Section 1206.115 Mineral Resources OFFICE OF SURFACE... VALUATION Federal Oil § 1206.115 What are my reporting requirements under a non-arm's-length transportation...

  18. 30 CFR 1206.115 - What are my reporting requirements under a non-arm's-length transportation arrangement?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 3 2013-07-01 2013-07-01 false What are my reporting requirements under a non-arm's-length transportation arrangement? 1206.115 Section 1206.115 Mineral Resources OFFICE OF NATURAL....115 What are my reporting requirements under a non-arm's-length transportation arrangement? (a) You or...

  19. 30 CFR 1206.115 - What are my reporting requirements under a non-arm's-length transportation arrangement?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 3 2012-07-01 2012-07-01 false What are my reporting requirements under a non-arm's-length transportation arrangement? 1206.115 Section 1206.115 Mineral Resources OFFICE OF NATURAL....115 What are my reporting requirements under a non-arm's-length transportation arrangement? (a) You or...

  20. 30 CFR 1206.115 - What are my reporting requirements under a non-arm's-length transportation arrangement?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 3 2014-07-01 2014-07-01 false What are my reporting requirements under a non-arm's-length transportation arrangement? 1206.115 Section 1206.115 Mineral Resources OFFICE OF NATURAL....115 What are my reporting requirements under a non-arm's-length transportation arrangement? (a) You or...

  1. Structural basis for allosteric cross-talk between the asymmetric nucleotide binding sites of a heterodimeric ABC exporter.

    PubMed

    Hohl, Michael; Hürlimann, Lea M; Böhm, Simon; Schöppe, Jendrik; Grütter, Markus G; Bordignon, Enrica; Seeger, Markus A

    2014-07-29

    ATP binding cassette (ABC) transporters mediate vital transport processes in every living cell. ATP hydrolysis, which fuels transport, displays positive cooperativity in numerous ABC transporters. In particular, heterodimeric ABC exporters exhibit pronounced allosteric coupling between a catalytically impaired degenerate site, where nucleotides bind tightly, and a consensus site, at which ATP is hydrolyzed in every transport cycle. Whereas the functional phenomenon of cooperativity is well described, its structural basis remains poorly understood. Here, we present the apo structure of the heterodimeric ABC exporter TM287/288 and compare it to the previously solved structure with adenosine 5'-(β,γ-imido)triphosphate (AMP-PNP) bound at the degenerate site. In contrast to other ABC exporter structures, the nucleotide binding domains (NBDs) of TM287/288 remain in molecular contact even in the absence of nucleotides, and the arrangement of the transmembrane domains (TMDs) is not influenced by AMP-PNP binding, a notion confirmed by double electron-electron resonance (DEER) measurements. Nucleotide binding at the degenerate site results in structural rearrangements, which are transmitted to the consensus site via two D-loops located at the NBD interface. These loops owe their name from a highly conserved aspartate and are directly connected to the catalytically important Walker B motif. The D-loop at the degenerate site ties the NBDs together even in the absence of nucleotides and substitution of its aspartate by alanine is well-tolerated. By contrast, the D-loop of the consensus site is flexible and the aspartate to alanine mutation and conformational restriction by cross-linking strongly reduces ATP hydrolysis and substrate transport.

  2. CREATING AN IPHONE APPLICATION FOR COLLECTING CONTINUOUS ABC DATA

    PubMed Central

    Whiting, Seth W; Dixon, Mark R

    2012-01-01

    This paper provides an overview and task analysis for creating a continuous ABC data-collection application using Xcode on a Mac computer. Behavior analysts can program an ABC data collection system, complete with a customized list of target clients, antecedents, behaviors, and consequences to be recorded, and have the data automatically sent to an e-mail account after observations have concluded. Further suggestions are provided to customize the ABC data- collection system for individual preferences and clinical needs. PMID:23060682

  3. Alternative transportation fuels: Infrastructure requirements and environmental impacts for ethanol and hydrogen

    NASA Astrophysics Data System (ADS)

    Wakeley, Heather L.

    Alternative fuels could replace a significant portion of the 140 billion gallons of annual US gasoline use. Considerable attention is being paid to processes and technologies for producing alternative fuels, but an enormous investment in new infrastructure will be needed to have substantial impact on the demand for petroleum. The economics of production, distribution, and use, along with environmental impacts of these fuels, will determine the success or failure of a transition away from US petroleum dependence. This dissertation evaluates infrastructure requirements for ethanol and hydrogen as alternative fuels. It begins with an economic case study for ethanol and hydrogen in Iowa. A large-scale linear optimization model is developed to estimate average transportation distances and costs for nationwide ethanol production and distribution systems. Environmental impacts of transportation in the ethanol life cycle are calculated using the Economic Input-Output Life Cycle Assessment (EIO-LCA) model. An EIO-LCA Hybrid method is developed to evaluate impacts of future fuel production technologies. This method is used to estimate emissions for hydrogen production and distribution pathways. Results from the ethanol analyses indicate that the ethanol transportation cost component is significant and is the most variable. Costs for ethanol sold in the Midwest, near primary production centers, are estimated to be comparable to or lower than gasoline costs. Along with a wide range of transportation costs, environmental impacts for ethanol range over three orders of magnitude, depending on the transport required. As a result, intensive ethanol use should be encouraged near ethanol production areas. Fossil fuels are likely to remain the primary feedstock sources for hydrogen production in the near- and mid-term. Costs and environmental impacts of hydrogen produced from natural gas and transported by pipeline are comparable to gasoline. However, capital costs are prohibitive and

  4. Goblet Cell Hyperplasia Requires High Bicarbonate Transport To Support Mucin Release.

    PubMed

    Gorrieri, Giulia; Scudieri, Paolo; Caci, Emanuela; Schiavon, Marco; Tomati, Valeria; Sirci, Francesco; Napolitano, Francesco; Carrella, Diego; Gianotti, Ambra; Musante, Ilaria; Favia, Maria; Casavola, Valeria; Guerra, Lorenzo; Rea, Federico; Ravazzolo, Roberto; Di Bernardo, Diego; Galietta, Luis J V

    2016-10-27

    Goblet cell hyperplasia, a feature of asthma and other respiratory diseases, is driven by the Th-2 cytokines IL-4 and IL-13. In human bronchial epithelial cells, we find that IL-4 induces the expression of many genes coding for ion channels and transporters, including TMEM16A, SLC26A4, SLC12A2, and ATP12A. At the functional level, we find that IL-4 enhances calcium- and cAMP-activated chloride/bicarbonate secretion, resulting in high bicarbonate concentration and alkaline pH in the fluid covering the apical surface of epithelia. Importantly, mucin release, elicited by purinergic stimulation, requires the presence of bicarbonate in the basolateral solution and is defective in cells derived from cystic fibrosis patients. In conclusion, our results suggest that Th-2 cytokines induce a profound change in expression and function in multiple ion channels and transporters that results in enhanced bicarbonate transport ability. This change is required as an important mechanism to favor release and clearance of mucus.

  5. Goblet Cell Hyperplasia Requires High Bicarbonate Transport To Support Mucin Release

    PubMed Central

    Gorrieri, Giulia; Scudieri, Paolo; Caci, Emanuela; Schiavon, Marco; Tomati, Valeria; Sirci, Francesco; Napolitano, Francesco; Carrella, Diego; Gianotti, Ambra; Musante, Ilaria; Favia, Maria; Casavola, Valeria; Guerra, Lorenzo; Rea, Federico; Ravazzolo, Roberto; Di Bernardo, Diego; Galietta, Luis J. V.

    2016-01-01

    Goblet cell hyperplasia, a feature of asthma and other respiratory diseases, is driven by the Th-2 cytokines IL-4 and IL-13. In human bronchial epithelial cells, we find that IL-4 induces the expression of many genes coding for ion channels and transporters, including TMEM16A, SLC26A4, SLC12A2, and ATP12A. At the functional level, we find that IL-4 enhances calcium- and cAMP-activated chloride/bicarbonate secretion, resulting in high bicarbonate concentration and alkaline pH in the fluid covering the apical surface of epithelia. Importantly, mucin release, elicited by purinergic stimulation, requires the presence of bicarbonate in the basolateral solution and is defective in cells derived from cystic fibrosis patients. In conclusion, our results suggest that Th-2 cytokines induce a profound change in expression and function in multiple ion channels and transporters that results in enhanced bicarbonate transport ability. This change is required as an important mechanism to favor release and clearance of mucus. PMID:27786259

  6. Minimum requirements for predictive pore-network modeling of solute transport in micromodels

    NASA Astrophysics Data System (ADS)

    Mehmani, Yashar; Tchelepi, Hamdi A.

    2017-10-01

    Pore-scale models are now an integral part of analyzing fluid dynamics in porous materials (e.g., rocks, soils, fuel cells). Pore network models (PNM) are particularly attractive due to their computational efficiency. However, quantitative predictions with PNM have not always been successful. We focus on single-phase transport of a passive tracer under advection-dominated regimes and compare PNM with high-fidelity direct numerical simulations (DNS) for a range of micromodel heterogeneities. We identify the minimum requirements for predictive PNM of transport. They are: (a) flow-based network extraction, i.e., discretizing the pore space based on the underlying velocity field, (b) a Lagrangian (particle tracking) simulation framework, and (c) accurate transfer of particles from one pore throat to the next. We develop novel network extraction and particle tracking PNM methods that meet these requirements. Moreover, we show that certain established PNM practices in the literature can result in first-order errors in modeling advection-dominated transport. They include: all Eulerian PNMs, networks extracted based on geometric metrics only, and flux-based nodal transfer probabilities. Preliminary results for a 3D sphere pack are also presented. The simulation inputs for this work are made public to serve as a benchmark for the research community.

  7. Synthesis from Design Requirements of a Hybrid System for Transport Aircraft Longitudinal Control. Volume 1

    NASA Technical Reports Server (NTRS)

    Hynes, Charles S.; Hardy, Gordon H.; Sherry, Lance

    2007-01-01

    Volume I of this report presents a new method for synthesizing hybrid systems directly from design requirements, and applies the method to design of a hybrid system for longitudinal control of transport aircraft. The resulting system satisfies general requirement for safety and effectiveness specified a priori, enabling formal validation to be achieved. Volume II contains seven appendices intended to make the report accessible to readers with backgrounds in human factors, fli ght dynamics and control. and formal logic. Major design goals are (1) system desi g n integrity based on proof of correctness at the design level, (2), significant simplification and cost reduction in system development and certification, and (3) improved operational efficiency, with significant alleviation of human-factors problems encountered by pilots in current transport aircraft. This report provides for the first time a firm technical basis for criteria governing design and certification of avionic systems for transport aircraft. It should be of primary interest to designers of next-generation avionic systems.

  8. Connected vehicle impacts on transportation planning technical memorandum #6: skills and expertise required to incorporate connected vehicles into transportation planning.

    DOT National Transportation Integrated Search

    2016-02-08

    Professional development and training are essential to the incorporation of connected/automated vehicles (C/AV) into the transportation planning process. In order to guarantee a successful deployment, transportation planning agencies and their stakeh...

  9. Technology requirements for advanced earth-orbital transportation systems, dual-mode propulsion

    NASA Technical Reports Server (NTRS)

    Haefeli, R. C.; Littler, E. G.; Hurley, J. B.; Winter, M. G.

    1977-01-01

    The application of dual-mode propulsion concepts to fully reusable single-stage-to-orbit (SSTO) vehicles is discussed. Dual-mode propulsion uses main rocket engines that consume hydrocarbon fuels as well as liquid hydrogen fuel. Liquid oxygen is used as the oxidizer. These engine concepts were integrated into transportation vehicle designs capable of vertical takeoff, delivering a payload to earth orbit, and return to earth with a horizontal landing. Benefits of these vehicles were assessed and compared with vehicles using single-mode propulsion (liquid hydrogen and oxygen engines). Technology requirements for such advanced transportation systems were identified. Figures of merit, including life-cycle cost savings and research costs, were derived for dual-mode technology programs, and were used for assessments of potential benefits of proposed technology activities. Dual-mode propulsion concepts display potential for significant cost and performance benefits when applied to SSTO vehicles.

  10. Motion/visual cueing requirements for vortex encounters during simulated transport visual approach and landing

    NASA Technical Reports Server (NTRS)

    Parrish, R. V.; Bowles, R. L.

    1983-01-01

    This paper addresses the issues of motion/visual cueing fidelity requirements for vortex encounters during simulated transport visual approaches and landings. Four simulator configurations were utilized to provide objective performance measures during simulated vortex penetrations, and subjective comments from pilots were collected. The configurations used were as follows: fixed base with visual degradation (delay), fixed base with no visual degradation, moving base with visual degradation (delay), and moving base with no visual degradation. The statistical comparisons of the objective measures and the subjective pilot opinions indicated that although both minimum visual delay and motion cueing are recommended for the vortex penetration task, the visual-scene delay characteristics were not as significant a fidelity factor as was the presence of motion cues. However, this indication was applicable to a restricted task, and to transport aircraft. Although they were statistically significant, the effects of visual delay and motion cueing on the touchdown-related measures were considered to be of no practical consequence.

  11. Carbachol-induced colonic mucus formation requires transport via NKCC1, K+ channels and CFTR

    PubMed Central

    Lindén, Sara K.; Alwan, Ala H.; Scholte, Bob J.; Hansson, Gunnar C.; Sjövall, Henrik

    2016-01-01

    The colonic mucosa protects itself from the luminal content by secreting mucus that keeps the bacteria at a distance from the epithelium. For this barrier to be effective, the mucus has to be constantly replenished which involves exocytosis and expansion of the secreted mucins. Mechanisms involved in regulation of mucus exocytosis and expansion are poorly understood, and the aim of this study was to investigate whether epithelial anion secretion regulates mucus formation in the colon. The muscarinic agonist carbachol was used to induce parallel secretion of anions and mucus, and by using established inhibitors of ion transport, we studied how inhibition of epithelial transport affected mucus formation in mouse colon. Anion secretion and mucin exocytosis were measured by changes in membrane current and epithelial capacitance, respectively. Mucus thickness measurements were used to determine the carbachol effect on mucus growth. The results showed that the carbachol-induced increase in membrane current was dependent on NKCC1 co-transport, basolateral K+ channels and Cftr activity. In contrast, the carbachol-induced increase in capacitance was partially dependent on NKCC1 and K+ channel activity, but did not require Cftr activity. Carbachol also induced an increase in mucus thickness that was inhibited by the NKCC1 blocker bumetanide. However, mice that lacked a functional Cftr channel did not respond to carbachol with an increase in mucus thickness, suggesting that carbachol-induced mucin expansion requires Cftr channel activity. In conclusion, these findings suggest that colonic epithelial transport regulates mucus formation by affecting both exocytosis and expansion of the mucin molecules. PMID:25139191

  12. Nonlinear resonances in the ABC-flow

    NASA Astrophysics Data System (ADS)

    Didov, A. A.; Uleysky, M. Yu.

    2018-01-01

    In this paper, we study resonances of the ABC-flow in the near integrable case ( C ≪1 ). This is an interesting example of a Hamiltonian system with 3/2 degrees of freedom in which simultaneous existence of two resonances of the same order is possible. Analytical conditions of the resonance existence are received. It is shown numerically that the largest n :1 (n = 1, 2, 3) resonances exist, and their energies are equal to theoretical energies in the near integrable case. We provide analytical and numerical evidences for existence of two branches of the two largest n :1 (n = 1, 2) resonances in the region of finite motion.

  13. Ebola virus entry requires the cholesterol transporter Niemann-Pick C1.

    PubMed

    Carette, Jan E; Raaben, Matthijs; Wong, Anthony C; Herbert, Andrew S; Obernosterer, Gregor; Mulherkar, Nirupama; Kuehne, Ana I; Kranzusch, Philip J; Griffin, April M; Ruthel, Gordon; Dal Cin, Paola; Dye, John M; Whelan, Sean P; Chandran, Kartik; Brummelkamp, Thijn R

    2011-08-24

    Infections by the Ebola and Marburg filoviruses cause a rapidly fatal haemorrhagic fever in humans for which no approved antivirals are available. Filovirus entry is mediated by the viral spike glycoprotein (GP), which attaches viral particles to the cell surface, delivers them to endosomes and catalyses fusion between viral and endosomal membranes. Additional host factors in the endosomal compartment are probably required for viral membrane fusion; however, despite considerable efforts, these critical host factors have defied molecular identification. Here we describe a genome-wide haploid genetic screen in human cells to identify host factors required for Ebola virus entry. Our screen uncovered 67 mutations disrupting all six members of the homotypic fusion and vacuole protein-sorting (HOPS) multisubunit tethering complex, which is involved in the fusion of endosomes to lysosomes, and 39 independent mutations that disrupt the endo/lysosomal cholesterol transporter protein Niemann-Pick C1 (NPC1). Cells defective for the HOPS complex or NPC1 function, including primary fibroblasts derived from human Niemann-Pick type C1 disease patients, are resistant to infection by Ebola virus and Marburg virus, but remain fully susceptible to a suite of unrelated viruses. We show that membrane fusion mediated by filovirus glycoproteins and viral escape from the vesicular compartment require the NPC1 protein, independent of its known function in cholesterol transport. Our findings uncover unique features of the entry pathway used by filoviruses and indicate potential antiviral strategies to combat these deadly agents.

  14. BIG: a calossin-like protein required for polar auxin transport in Arabidopsis

    PubMed Central

    Gil, Pedro; Dewey, Elizabeth; Friml, Jiri; Zhao, Yunde; Snowden, Kimberley C.; Putterill, Jo; Palme, Klaus; Estelle, Mark; Chory, Joanne

    2001-01-01

    Polar auxin transport is crucial for the regulation of auxin action and required for some light-regulated responses during plant development. We have found that two mutants of Arabidopsis—doc1, which displays altered expression of light-regulated genes, and tir3, known for its reduced auxin transport—have similar defects and define mutations in a single gene that we have renamed BIG. BIG is very similar to the Drosophila gene Calossin/Pushover, a member of a gene family also present in Caenorhabditis elegans and human genomes. The protein encoded by BIG is extraordinary in size, 560 kD, and contains several putative Zn-finger domains. Expression-profiling experiments indicate that altered expression of multiple light-regulated genes in doc1 mutants can be suppressed by elevated levels of auxin caused by overexpression of an auxin biosynthetic gene, suggesting that normal auxin distribution is required to maintain low-level expression of these genes in the dark. Double mutants of tir3 with the auxin mutants pin1, pid, and axr1 display severe defects in auxin-dependent growth of the inflorescence. Chemical inhibitors of auxin transport change the intracellular localization of the auxin efflux carrier PIN1 in doc1/tir3 mutants, supporting the idea that BIG is required for normal auxin efflux. PMID:11485992

  15. Miro's N-Terminal GTPase Domain Is Required for Transport of Mitochondria into Axons and Dendrites

    PubMed Central

    Babic, Milos; Russo, Gary J.; Wellington, Andrea J.; Sangston, Ryan M.; Gonzalez, Migdalia

    2015-01-01

    Mitochondria are dynamically transported in and out of neuronal processes to maintain neuronal excitability and synaptic function. In higher eukaryotes, the mitochondrial GTPase Miro binds Milton/TRAK adaptor proteins linking microtubule motors to mitochondria. Here we show that Drosophila Miro (dMiro), which has previously been shown to be required for kinesin-driven axonal transport, is also critically required for the dynein-driven distribution of mitochondria into dendrites. In addition, we used the loss-of-function mutations dMiroT25N and dMiroT460N to determine the significance of dMiro's N-terminal and C-terminal GTPase domains, respectively. Expression of dMiroT25N in the absence of endogenous dMiro caused premature lethality and arrested development at a pupal stage. dMiroT25N accumulated mitochondria in the soma of larval motor and sensory neurons, and prevented their kinesin-dependent and dynein-dependent distribution into axons and dendrites, respectively. dMiroT25N mutant mitochondria also were severely fragmented and exhibited reduced kinesin and dynein motility in axons. In contrast, dMiroT460N did not impair viability, mitochondrial size, or the distribution of mitochondria. However, dMiroT460N reduced dynein motility during retrograde mitochondrial transport in axons. Finally, we show that substitutions analogous to the constitutively active Ras-G12V mutation in dMiro's N-terminal and C-terminal GTPase domains cause neomorphic phenotypic effects that are likely unrelated to the normal function of each GTPase domain. Overall, our analysis indicates that dMiro's N-terminal GTPase domain is critically required for viability, mitochondrial size, and the distribution of mitochondria out of the neuronal soma regardless of the employed motor, likely by promoting the transition from a stationary to a motile state. PMID:25855186

  16. Concepts for Life Cycle Cost Control Required to Achieve Space Transportation Affordability and Sustainability

    NASA Technical Reports Server (NTRS)

    Rhodes, Russel E.; Zapata, Edgar; Levack, Daniel J. H.; Robinson, John W.; Donahue, Benjamin B.

    2009-01-01

    Cost control must be implemented through the establishment of requirements and controlled continually by managing to these requirements. Cost control of the non-recurring side of life cycle cost has traditionally been implemented in both commercial and government programs. The government uses the budget process to implement this control. The commercial approach is to use a similar process of allocating the non-recurring cost to major elements of the program. This type of control generally manages through a work breakdown structure (WBS) by defining the major elements of the program. If the cost control is to be applied across the entire program life cycle cost (LCC), the approach must be addressed very differently. A functional breakdown structure (FBS) is defined and recommended. Use of a FBS provides the visibifity to allow the choice of an integrated solution reducing the cost of providing many different elements of like function. The different functional solutions that drive the hardware logistics, quantity of documentation, operational labor, reliability and maintainability balance, and total integration of the entire system from DDT&E through the life of the program must be fully defined, compared, and final decisions made among these competing solutions. The major drivers of recurring cost have been identified and are presented and discussed. The LCC requirements must be established and flowed down to provide control of LCC. This LCC control will require a structured rigid process similar to the one traditionally used to control weight/performance for space transportation systems throughout the entire program. It has been demonstrated over the last 30 years that without a firm requirement and methodically structured cost control, it is unlikely that affordable and sustainable space transportation system LCC will be achieved.

  17. Technology requirements for future Earth-to-geosynchronous orbit transportation systems. Volume 3: Appendices

    NASA Technical Reports Server (NTRS)

    Caluori, V. A.; Conrad, R. T.; Jenkins, J. C.

    1980-01-01

    Technological requirements and forecasts of rocket engine parameters and launch vehicles for future Earth to geosynchronous orbit transportation systems are presented. The parametric performance, weight, and envelope data for the LOX/CH4, fuel cooled, staged combustion cycle and the hydrogen cooled, expander bleed cycle engine concepts are discussed. The costing methodology and ground rules used to develop the engine study are summarized. The weight estimating methodology for winged launched vehicles is described and summary data, used to evaluate and compare weight data for dedicated and integrated O2/H2 subsystems for the SSTO, HLLV and POTV are presented. Detail weights, comparisons, and weight scaling equations are provided.

  18. Assessment and Requirements of Nuclear Reaction Databases for GCR Transport in the Atmosphere and Structures

    NASA Technical Reports Server (NTRS)

    Cucinotta, F. A.; Wilson, J. W.; Shinn, J. L.; Tripathi, R. K.

    1998-01-01

    The transport properties of galactic cosmic rays (GCR) in the atmosphere, material structures, and human body (self-shielding) am of interest in risk assessment for supersonic and subsonic aircraft and for space travel in low-Earth orbit and on interplanetary missions. Nuclear reactions, such as knockout and fragmentation, present large modifications of particle type and energies of the galactic cosmic rays in penetrating materials. We make an assessment of the current nuclear reaction models and improvements in these model for developing required transport code data bases. A new fragmentation data base (QMSFRG) based on microscopic models is compared to the NUCFRG2 model and implications for shield assessment made using the HZETRN radiation transport code. For deep penetration problems, the build-up of light particles, such as nucleons, light clusters and mesons from nuclear reactions in conjunction with the absorption of the heavy ions, leads to the dominance of the charge Z = 0, 1, and 2 hadrons in the exposures at large penetration depths. Light particles are produced through nuclear or cluster knockout and in evaporation events with characteristically distinct spectra which play unique roles in the build-up of secondary radiation's in shielding. We describe models of light particle production in nucleon and heavy ion induced reactions and make an assessment of the importance of light particle multiplicity and spectral parameters in these exposures.

  19. A Manual for Implementation of ABC Video Duplication Projects.

    ERIC Educational Resources Information Center

    Hill, Joseph, Ed.

    The ABC (Appalachian BOCES Consortium) consists of 10 BOCES (Boards of Cooperative Educational Services) which serve the 14 southern counties of New York State designated as Appalachia. Each year since 1974, the ABC has participated in regional video duplication projects, which have yielded a total of nearly 4,000 video titles. The complexity of…

  20. ABCs of Being Smart: S Is for Supporting

    ERIC Educational Resources Information Center

    Foster, Joanne

    2014-01-01

    Joanne Foster's article "R We There Yet?" was first published in "Parenting for High Potential" ("PHP") in 2006, which became the springboard for the "ABCs of Being Smart" series of columns. At that time, Foster invited "PHP" readers to think about their own versions of the "ABCs of Being…

  1. Effect of SOS-induced levels of imuABC on spontaneous and damage-induced mutagenesis in Caulobacter crescentus.

    PubMed

    Alves, Ingrid R; Lima-Noronha, Marco A; Silva, Larissa G; Fernández-Silva, Frank S; Freitas, Aline Luiza D; Marques, Marilis V; Galhardo, Rodrigo S

    2017-11-01

    imuABC (imuAB dnaE2) genes are responsible for SOS-mutagenesis in Caulobacter crescentus and other bacterial species devoid of umuDC. In this work, we have constructed operator-constitutive mutants of the imuABC operon. We used this genetic tool to investigate the effect of SOS-induced levels of these genes upon both spontaneous and damage-induced mutagenesis. We showed that constitutive expression of imuABC does not increase spontaneous or damage-induced mutagenesis, nor increases cellular resistance to DNA-damaging agents. Nevertheless, the presence of the operator-constitutive mutation rescues mutagenesis in a recA background, indicating that imuABC are the only genes required at SOS-induced levels for translesion synthesis (TLS) in C. crescentus. Furthermore, these data also show that TLS mediated by ImuABC does not require RecA, unlike umuDC-dependent mutagenesis in E. coli. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Air transport of patients with pneumothorax: is tube thoracostomy required before flight?

    PubMed

    Braude, Darren; Tutera, Dominic; Tawil, Issac; Pirkl, Gregory

    2014-01-01

    It is conventionally thought that patients with pneumothorax (PTX) require tube thoracostomy (TT) before air medical transport (AMT), especially in unpressurized rotor-wing (RW) aircraft, to prevent deterioration from expansion of the PTX or development of tension PTX. We hypothesize that patients with PTX transported without TT tolerate RW AMT without serious deterioration, as defined by hypotension, hypoxemia, respiratory distress, intubation, bag valve mask ventilation, needle thoracostomy (NT), or cardiac arrest during transport. We conducted a retrospective review of a case-series of trauma patients transported to a single Level 1 trauma center via RW with confirmed PTX and no TT. Using standardized abstraction forms, we reviewed charts for signs of deterioration. Those patients identified as having clinical deterioration were independently reviewed for the likelihood that the clinical deterioration was a direct consequence of PTX. During the study period, 66 patients with confirmed PTX underwent RW AMT with an average altitude gain of 1890 feet, an average barometric pressure 586-600 mmHg, and average flight duration of 28 minutes. All patients received oxygen therapy; 14/66 patients (21%) were supported with positive pressure ventilation. Eleven of 66 patients (17%) had NT placed before flight and 4/66 (6%) had NT placed during flight. Four of 66 patients (6% CI0.3-11.7) may have deteriorated during AMT as a result of PTX; all were successfully managed with NT. In this series, 6% of patients with PTX deteriorated as result of AMT without TT, yet all patients were managed successfully with NT. Routine placement of TT in patients with PTX before RW AMT may not be necessary. Further prospective evaluation is warranted. Copyright © 2014 Air Medical Journal Associates. Published by Elsevier Inc. All rights reserved.

  3. Simulation-based estimation of mean and standard deviation for meta-analysis via Approximate Bayesian Computation (ABC).

    PubMed

    Kwon, Deukwoo; Reis, Isildinha M

    2015-08-12

    When conducting a meta-analysis of a continuous outcome, estimated means and standard deviations from the selected studies are required in order to obtain an overall estimate of the mean effect and its confidence interval. If these quantities are not directly reported in the publications, they must be estimated from other reported summary statistics, such as the median, the minimum, the maximum, and quartiles. We propose a simulation-based estimation approach using the Approximate Bayesian Computation (ABC) technique for estimating mean and standard deviation based on various sets of summary statistics found in published studies. We conduct a simulation study to compare the proposed ABC method with the existing methods of Hozo et al. (2005), Bland (2015), and Wan et al. (2014). In the estimation of the standard deviation, our ABC method performs better than the other methods when data are generated from skewed or heavy-tailed distributions. The corresponding average relative error (ARE) approaches zero as sample size increases. In data generated from the normal distribution, our ABC performs well. However, the Wan et al. method is best for estimating standard deviation under normal distribution. In the estimation of the mean, our ABC method is best regardless of assumed distribution. ABC is a flexible method for estimating the study-specific mean and standard deviation for meta-analysis, especially with underlying skewed or heavy-tailed distributions. The ABC method can be applied using other reported summary statistics such as the posterior mean and 95 % credible interval when Bayesian analysis has been employed.

  4. GLUT4 Retention in Adipocytes Requires Two Intracellular Insulin-regulated Transport Steps

    PubMed Central

    Zeigerer, Anja; Lampson, Michael A.; Karylowski, Ola; Sabatini, David D.; Adesnik, Milton; Ren, Mindong; McGraw, Timothy E.

    2002-01-01

    Insulin regulates glucose uptake into fat and muscle by modulating the distribution of the GLUT4 glucose transporter between the surface and interior of cells. The GLUT4 trafficking pathway overlaps with the general endocytic recycling pathway, but the degree and functional significance of the overlap are not known. In this study of intact adipocytes, we demonstrate, by using a compartment-specific fluorescence-quenching assay, that GLUT4 is equally distributed between two intracellular pools: the transferrin receptor-containing endosomes and a specialized compartment that excludes the transferrin receptor. These pools of GLUT4 are in dynamic communication with one another and with the cell surface. Insulin-induced redistribution of GLUT4 to the surface requires mobilization of both pools. These data establish a role for the general endosomal system in the specialized, insulin-regulated trafficking of GLUT4. Trafficking through the general endosomal system is regulated by rab11. Herein, we show that rab11 is required for the transport of GLUT4 from endosomes to the specialized compartment and for the insulin-induced translocation to the cell surface, emphasizing the importance of the general endosomal pathway in the specialized trafficking of GLUT4. Based on these findings we propose a two-step model for GLUT4 trafficking in which the general endosomal recycling compartment plays a specialized role in the insulin-regulated traffic of GLUT4. This compartment-based model provides the framework for understanding insulin-regulated trafficking at a molecular level. PMID:12134080

  5. GLUT4 retention in adipocytes requires two intracellular insulin-regulated transport steps.

    PubMed

    Zeigerer, Anja; Lampson, Michael A; Karylowski, Ola; Sabatini, David D; Adesnik, Milton; Ren, Mindong; McGraw, Timothy E

    2002-07-01

    Insulin regulates glucose uptake into fat and muscle by modulating the distribution of the GLUT4 glucose transporter between the surface and interior of cells. The GLUT4 trafficking pathway overlaps with the general endocytic recycling pathway, but the degree and functional significance of the overlap are not known. In this study of intact adipocytes, we demonstrate, by using a compartment-specific fluorescence-quenching assay, that GLUT4 is equally distributed between two intracellular pools: the transferrin receptor-containing endosomes and a specialized compartment that excludes the transferrin receptor. These pools of GLUT4 are in dynamic communication with one another and with the cell surface. Insulin-induced redistribution of GLUT4 to the surface requires mobilization of both pools. These data establish a role for the general endosomal system in the specialized, insulin-regulated trafficking of GLUT4. Trafficking through the general endosomal system is regulated by rab11. Herein, we show that rab11 is required for the transport of GLUT4 from endosomes to the specialized compartment and for the insulin-induced translocation to the cell surface, emphasizing the importance of the general endosomal pathway in the specialized trafficking of GLUT4. Based on these findings we propose a two-step model for GLUT4 trafficking in which the general endosomal recycling compartment plays a specialized role in the insulin-regulated traffic of GLUT4. This compartment-based model provides the framework for understanding insulin-regulated trafficking at a molecular level.

  6. Drosophila divalent metal ion transporter Malvolio is required in dopaminergic neurons for feeding decisions.

    PubMed

    Søvik, E; LaMora, A; Seehra, G; Barron, A B; Duncan, J G; Ben-Shahar, Y

    2017-06-01

    Members of the natural resistance-associated macrophage protein (NRAMP) family are evolutionarily conserved metal ion transporters that play an essential role in regulating intracellular divalent cation homeostasis in both prokaryotes and eukaryotes. Malvolio (Mvl), the sole NRAMP family member in insects, plays a role in food choice behaviors in Drosophila and other species. However, the specific physiological and cellular processes that require the action of Mvl for appropriate feeding decisions remain elusive. Here, we show that normal food choice requires Mvl function specifically in the dopaminergic system, and can be rescued by supplementing food with manganese. Collectively, our data indicate that the action of the Mvl transporter affects food choice behavior via the regulation of dopaminergic innervation of the mushroom bodies, a principle brain region associated with decision-making in insects. Our studies suggest that the homeostatic regulation of the intraneuronal levels of divalent cations plays an important role in the development and function of the dopaminergic system and associated behaviors. © 2017 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

  7. The Drosophila divalent metal ion transporter Malvolio is required in dopaminergic neurons for feeding decisions

    PubMed Central

    Søvik, Eirik; LaMora, Angela; Seehra, Gurpreet; Barron, Andrew B.; Duncan, Jennifer G.; Ben-Shahar, Yehuda

    2017-01-01

    Members of the Natural resistance-associated macrophage protein (NRAMP) family are evolutionarily-conserved metal ion transporters that play an essential role in regulating intracellular divalent cation homeostasis in both prokaryotes and eukaryotes. Malvolio (Mvl), the sole NRAMP family member in insects, plays a role in food choice behaviors in Drosophila and other species. However, the specific physiological and cellular processes that require the action of Mvl for appropriate feeding decisions remain elusive. Here we demonstrate that normal food choice requires Mvl function specifically in the dopaminergic system, and can be rescued by supplementing food with manganese. Collectively, our data indicate that the action of the Mvl transporter affects food choice behavior via the regulation of dopaminergic innervation of the mushroom bodies, a principle brain region associated with decision making in insects. Our studies suggest that the homeostatic regulation of the intra-neuronal levels of divalent cations plays an important role in the development and function of the dopaminergic system and associated behaviors. PMID:28220999

  8. Comparing the results of DAADD and ABC of children included in autism spectrum disorders.

    PubMed

    Barbosa, Milene Rossi Pereira; Fernandes, Fernanda Dreux Miranda

    2014-01-01

    To verify if there are characteristic behaviors of the different diagnosis included in the autism spectrum according to the Differential Assessment of Autism and Other Developmental Disorders (DAADD) and to the Autism Behavior Checklist (ABC). Participants were 45 individuals and their respective speech-language therapists. All therapists are graduate students working with the children for at least 1 year. This time was considered sufficient to the therapists to have the information required by the DAADD questionnaire. It is comprised by 3 protocols specifically designed to children with 2 to 4 years, 4 to 6 years and 6 to 8 years, the same criteria used to separate the research groups, G1, G2 and G3, respectively. Data referring to the ABC were retrieved from the subject's files at the Laboratório de Investigação Fonoaudiológica nos Distúrbios do Espectro do Autismo (Research Laboratory on Language Disorders in the Autism Spectrum) of the School of Medicine, Universidade de São Paulo, where it is routinely applied during the annual assessment. Answers to the different areas of DAADD are similar to the different areas of ABC. These data show data the diagnosis by DAADD is easier in older children. Although there is no significant difference, the large occurrence of Rett's syndrome diagnosis according to the DAADD was associated to higher risk for autism according to the ABC in G1. With increasing age this tendency decreases and either in G2 and G3 Autism is the most frequent diagnosis. Although the results of both questionnaires tend to agree more with increasing age, the DAADD is more sensitive in the different ages while the ABC if more specific only to older children.

  9. A two-component response regulator, gltR, is required for glucose transport activity in Pseudomonas aeruginosa PAO1.

    PubMed Central

    Sage, A E; Proctor, W D; Phibbs, P V

    1996-01-01

    A 729-bp open reading frame (gltR) was identified in Pseudomonas aeruginosa PAO1 that encodes a product homologous to the two-component response regulator family of proteins. Disruption of gltR caused loss of glucose transport activity. Restoration of gltR resulted in wild-type levels of glucose transport. These findings indicate that gltR is required for expression of the glucose transport system in P. aeruginosa. PMID:8830708

  10. 30 CFR 1206.114 - What are my reporting requirements under an arm's-length transportation contract?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 3 2014-07-01 2014-07-01 false What are my reporting requirements under an arm....114 What are my reporting requirements under an arm's-length transportation contract? You or your... costs you or your affiliate incur. ONRR may require you or your affiliate to submit arm's-length...

  11. 30 CFR 1206.114 - What are my reporting requirements under an arm's-length transportation contract?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 3 2013-07-01 2013-07-01 false What are my reporting requirements under an arm....114 What are my reporting requirements under an arm's-length transportation contract? You or your... costs you or your affiliate incur. ONRR may require you or your affiliate to submit arm's-length...

  12. 30 CFR 206.114 - What are my reporting requirements under an arm's-length transportation contract?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What are my reporting requirements under an arm... What are my reporting requirements under an arm's-length transportation contract? You or your affiliate... you or your affiliate incur. MMS may require you or your affiliate to submit arm's-length...

  13. 30 CFR 1206.114 - What are my reporting requirements under an arm's-length transportation contract?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 3 2012-07-01 2012-07-01 false What are my reporting requirements under an arm....114 What are my reporting requirements under an arm's-length transportation contract? You or your... costs you or your affiliate incur. ONRR may require you or your affiliate to submit arm's-length...

  14. 41 CFR 102-118.25 - Does GSA still require my agency to submit its overall transportation policies for approval?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Public Contracts and Property Management Federal Property Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION TRANSPORTATION 118-TRANSPORTATION PAYMENT AND AUDIT General Introduction... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Does GSA still require...

  15. 76 FR 14643 - Hazardous Materials: Safety Requirements for External Product Piping on Cargo Tanks Transporting...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-17

    ... for External Product Piping on Cargo Tanks Transporting Flammable Liquids AGENCY: Pipeline and...) seeking public comment on a proposal to prohibit the transportation of flammable liquids in exposed... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration 49 CFR Part...

  16. β-Phenylethylamine requires the dopamine transporter to increase extracellular dopamine in Caenorhabditis elegans dopaminergic neurons.

    PubMed

    Hossain, Murad; Wickramasekara, Rochelle N; Carvelli, Lucia

    2014-07-01

    β-Phenylethylamine (βPEA) is an endogenous amine that has been shown to increase the synaptic levels of dopamine (DA). A number of in vitro and behavioral studies suggest the dopamine transporter (DAT) plays a role in the effects generated by βPEA, however the mechanism through which βPEA affects DAT has not yet been elucidated. Here, we used Caenorhabditis (C.) elegans DAT (DAT-1) expressing LLC-pk1 cells and neuronal cultures to investigate whether the βPEA-induced increase of extracellular DA required DAT-1. Our data show that βPEA increases extracellular dopamine both in DAT-1 transfected cells and cultures of differentiated neurons. RTI-55, a cocaine homologue and DAT inhibitor, completely blocked the βPEA-induced effect in transfected cells. However in neuronal cultures, RTI-55 only partly inhibited the increase of extracellular DA generated by βPEA. These results suggest that βPEA requires DAT-1 and other, not yet identified proteins, to increase extracellular DA when tested in a native system. Furthermore, our results suggest that βPEA-induced increase of extracellular DA does not require functional monoamine vesicles as genetic ablation of the C. elegans homologue vesicular monoamine transporter, cat-1, did not compromise the ability of βPEA to increase extracellular DA. Finally, our electrophysiology data show that βPEA caused fast-rising and self-inactivating amperometric currents in a subset of wild-type DA neurons but not in neurons isolated from dat-1 knockout animals. Taken together, these data demonstrate that in both DA neurons and heterogeneous cultures of differentiated C. elegans neurons, βPEA releases cytoplasmic DA through DAT-1 to ultimately increase the extracellular concentration of DA. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. β-phenylethylamine Requires the Dopamine Transporter to Increase Extracellular Dopamine in C. elegans Dopaminergic Neurons

    PubMed Central

    Hossain, Murad; Wickramasekara, Rochelle N.; Carvelli, Lucia

    2013-01-01

    β-phenylethylamine (βPEA) is an endogenous amine that has been shown to increase the synaptic levels of dopamine (DA). A number of in vitro and behavioral studies suggest the dopamine transporter (DAT) plays a role in the effects generated by βPEA, however the mechanism through which βPEA affects DAT has not yet been elucidated. Here, we used Caenorhabditis (C.) elegans DAT (DAT-1) expressing LLC-pk1 cells and neuronal cultures to investigate whether the βPEA-induced increase of extracellular DA required DAT-1. Our data show that βPEA increases extracellular dopamine both in DAT-1 transfected cells and cultures of differentiated neurons. RTI-55, a cocaine homologue and DAT inhibitor, completely blocked the βPEA-induced effect in transfected cells. However in neuronal cultures, RTI-55 only partly inhibited the increase of extracellular DA generated by βPEA. These results suggest that βPEA requires DAT-1 and other, not yet identified proteins, to increase extracellular DA when tested in a native system. Furthermore, our results suggest that βPEA-induced increase of extracellular DA does not require functional monoamine vesicles as genetic ablation of the C. elegans homologue vesicular monoamine transporter, cat-1, did not compromise the ability of βPEA to increase extracellular DA. Finally, our electrophysiology data show that βPEA caused fast-rising and self-inactivating amperometric currents in a subset of wild-type DA neurons but not in neurons isolated from dat-1 knockout animals. Taken together, these data demonstrate that in both DA neurons and heterogeneous cultures of differentiated C. elegans neurons, βPEA releases cytoplasmic DA through DAT-1 to ultimately increase the extracellular concentration of DA. PMID:24161617

  18. Simulation Modeling Requirements for Loss-of-Control Accident Prevention of Turboprop Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Crider, Dennis; Foster, John V.

    2012-01-01

    . This paper addresses simulation modeling requirements that are unique to turboprop transport aircraft and highlights the growing need for aerodynamic models suitable for stall training for these configurations. A review of prominent accidents that involved aerodynamic stall is used to illustrate various modeling features unique to turboprop configurations and the impact of stall behavior on susceptibility to loss of control that has led to new training requirements. This is followed by an overview of stability and control behavior of straight-wing turboprops, the related aerodynamic characteristics, and a summary of recent experimental studies on icing effects. In addition, differences in flight dynamics behavior between swept-wing jets and straight-wing turboprop configurations are discussed to compare and contrast modeling requirements. Specific recommendations for aerodynamic models along with further research needs and data measurements are also provided. 1

  19. Quasiparticle renormalization in ABC graphene trilayers

    NASA Astrophysics Data System (ADS)

    Dou, Xu; Jaefari, Akbar; Barlas, Yafis; Uchoa, Bruno

    2015-03-01

    We investigate the effect of electron-electron interactions in ABC stacked graphene trilayers. In the gapless regime, we show that the self-energy corrections lead to the renormalization of the dynamical exponent z = 3 +α1 / N , with α1 ~ 0 . 52 and N is the number of fermionic species. Although the quasiparticle residue is suppressed near the neutrality point, the lifetime has a sublinear scaling with the energy and the quasiparticles are well defined even at zero energy. We calculate the renormalization of a variety of physical observables, which can be directly measured in experiments. X.D., A.J., and B.U. acknowledge University of Oklahoma for support. B.U. acknowledges NSF Career Grant No. DMR-1352604 for partial support.

  20. Automated container transportation using self-guided vehicles: Fernald site requirements

    SciTech Connect

    Hazen, F.B.

    1993-09-01

    A new opportunity to improve the safety and efficiency of environmental restoration operations, using robotics has emerged from advances in industry, academia, and government labs. Self-Guided Vehicles (SGV`s) have recently been developed in industry and early systems have already demonstrated much, though not all, of the functionality necessary to support driverless transportation of waste within and between processing facilities. Improved materials databases are being developed by at least two DOE remediation sites, the Fernald Environmental Management Project (FEME) in the State of Ohio and the Hanford Complex in the State of Washington. SGV`s can be developed that take advantage ofmore » the information in these databases and yield improved dispatch, waste tracking, report and shipment documentation. In addition, they will reduce the radiation hazard to workers and the risk of damaging containers through accidental collision. In this document, features of remediation sites that dictate the design of both the individual SGV`s and the collective system of SGV`s are presented, through the example of the site requirements at Fernald. Some concepts borrowed from the world of manufacturing are explained and then used to develop an integrated, holistic view of the remediation site as a pseudo-factory. Transportation methods at Fernald and anticipated growth in transport demand are analyzed. The new site-wide database under development at Fernald is presented so that advantageous and synergistic links between SGV`s and information systems can be analyzed. Details of the SGV development proposed are submitted, and some results of a recently completed state of the art survey for SGV use in this application are also presented.« less

  1. Reserpine-induced Reduction in Norepinephrine Transporter Function Requires Catecholamine Storage Vesicles

    PubMed Central

    Mandela, Prashant; Chandley, Michelle; Xu, Yao-Yu; Zhu, Meng-Yang; Ordway, Gregory A.

    2010-01-01

    Treatment of rats with reserpine, an inhibitor of the vesicular monoamine transporter (VMAT), depletes norepinephrine (NE) and regulates NE transporter (NET) expression. The present study examined the molecular mechanisms involved in regulation of the NET by reserpine using cultured cells. Exposure of rat PC12 cells to reserpine for a period as short as 5 min decreased [3H]NE uptake capacity, an effect characterized by a robust decrease in the Vmax of the transport of [3H]NE. As expected, reserpine did not displace the binding of [3H]nisoxetine from the NET in membrane homogenates. The potency of reserpine for reducing [3H]NE uptake was dramatically lower in SK-N-SH cells that have reduced storage capacity for catecholamines. Reserpine had no effect on [3H]NE uptake in HEK-293 cells transfected with the rat NET (293-hNET), cells that lack catecholamine storage vesicles. NET regulation by reserpine was independent of trafficking of the NET from the cell surface. Pre-exposure of cells to inhibitors of several intracellular signaling cascades known to regulate the NET, including Ca2+/Ca2+-calmodulin dependent kinase and protein kinases A, C and G, did not affect the ability of reserpine to reduce [3H]NE uptake. Treatment of PC12 cells with the catecholamine depleting agent, α-methyl-p-tyrosine, increased [3H]NE uptake and eliminated the inhibitory effects of reserpine on [3H]NE uptake. Reserpine non-competitively inhibits NET activity through a Ca2+-independent process that requires catecholamine storage vesicles, revealing a novel pharmacological method to modify NET function. Further characterization of the molecular nature of reserpine's action could lead to the development of alternative therapeutic strategies for treating disorders known to be benefitted by treatment with traditional competitive NET inhibitors. PMID:20176067

  2. Reserpine-induced reduction in norepinephrine transporter function requires catecholamine storage vesicles.

    PubMed

    Mandela, Prashant; Chandley, Michelle; Xu, Yao-Yu; Zhu, Meng-Yang; Ordway, Gregory A

    2010-01-01

    Treatment of rats with reserpine, an inhibitor of the vesicular monoamine transporter (VMAT), depletes norepinephrine (NE) and regulates NE transporter (NET) expression. The present study examined the molecular mechanisms involved in regulation of the NET by reserpine using cultured cells. Exposure of rat PC12 cells to reserpine for a period as short as 5min decreased [(3)H]NE uptake capacity, an effect characterized by a robust decrease in the V(max) of the transport of [(3)H]NE. As expected, reserpine did not displace the binding of [(3)H]nisoxetine from the NET in membrane homogenates. The potency of reserpine for reducing [(3)H]NE uptake was dramatically lower in SK-N-SH cells that have reduced storage capacity for catecholamines. Reserpine had no effect on [(3)H]NE uptake in HEK-293 cells transfected with the rat NET (293-hNET), cells that lack catecholamine storage vesicles. NET regulation by reserpine was independent of trafficking of the NET from the cell surface. Pre-exposure of cells to inhibitors of several intracellular signaling cascades known to regulate the NET, including Ca(2+)/Ca(2+)-calmodulin dependent kinase and protein kinases A, C and G, did not affect the ability of reserpine to reduce [(3)H]NE uptake. Treatment of PC12 cells with the catecholamine depleting agent, alpha-methyl-p-tyrosine, increased [(3)H]NE uptake and eliminated the inhibitory effects of reserpine on [(3)H]NE uptake. Reserpine non-competitively inhibits NET activity through a Ca(2+)-independent process that requires catecholamine storage vesicles, revealing a novel pharmacological method to modify NET function. Further characterization of the molecular nature of reserpine's action could lead to the development of alternative therapeutic strategies for treating disorders known to be benefitted by treatment with traditional competitive NET inhibitors. Copyright 2010 Elsevier Ltd. All rights reserved.

  3. CFTR is required for maximal transepithelial liquid transport in pig alveolar epithelia.

    PubMed

    Li, Xiaopeng; Comellas, Alejandro P; Karp, Philip H; Ernst, Sarah E; Moninger, Thomas O; Gansemer, Nicholas D; Taft, Peter J; Pezzulo, Alejandro A; Rector, Michael V; Rossen, Nathan; Stoltz, David A; McCray, Paul B; Welsh, Michael J; Zabner, Joseph

    2012-07-01

    A balance between alveolar liquid absorption and secretion is critical for maintaining optimal alveolar subphase liquid height and facilitating gas exchange in the alveolar space. However, the role of cystic fibrosis transmembrane regulator protein (CFTR) in this homeostatic process has remained elusive. Using a newly developed porcine model of cystic fibrosis, in which CFTR is absent, we investigated ion transport properties and alveolar liquid transport in isolated type II alveolar epithelial cells (T2AECs) cultured at the air-liquid interface. CFTR was distributed exclusively to the apical surface of cultured T2AECs. Alveolar epithelia from CFTR(-/-) pigs failed to increase liquid absorption in response to agents that increase cAMP, whereas cAMP-stimulated liquid absorption in CFTR(+/-) epithelia was similar to that in CFTR(+/+) epithelia. Expression of recombinant CFTR restored stimulated liquid absorption in CFTR(-/-) T2AECs but had no effect on CFTR(+/+) epithelia. In ex vivo studies of nonperfused lungs, stimulated liquid absorption was defective in CFTR(-/-) alveolar epithelia but similar between CFTR(+/+) and CFTR(+/-) epithelia. When epithelia were studied at the air-liquid interface, elevating cAMP levels increased subphase liquid height in CFTR(+/+) but not in CFTR(-/-) T2AECs. Our findings demonstrate that CFTR is required for maximal liquid absorption under cAMP stimulation, but it is not the rate-limiting factor. Furthermore, our data define a role for CFTR in liquid secretion by T2AECs. These insights may help to develop new treatment strategies for pulmonary edema and respiratory distress syndrome, diseases in which lung liquid transport is disrupted.

  4. The Arabidopsis DESPERADO/AtWBC11 transporter is required for cutin and wax secretion.

    PubMed

    Panikashvili, David; Savaldi-Goldstein, Sigal; Mandel, Tali; Yifhar, Tamar; Franke, Rochus B; Höfer, René; Schreiber, Lukas; Chory, Joanne; Aharoni, Asaph

    2007-12-01

    The cuticle fulfills multiple roles in the plant life cycle, including protection from environmental stresses and the regulation of organ fusion. It is largely composed of cutin, which consists of C(16-18) fatty acids. While cutin composition and biosynthesis have been studied, the export of cutin monomers out of the epidermis has remained elusive. Here, we show that DESPERADO (AtWBC11) (abbreviated DSO), encoding a plasma membrane-localized ATP-binding cassette transporter, is required for cutin transport to the extracellular matrix. The dso mutant exhibits an array of surface defects suggesting an abnormally functioning cuticle. This was accompanied by dramatic alterations in the levels of cutin monomers. Moreover, electron microscopy revealed unusual lipidic cytoplasmatic inclusions in epidermal cells, disappearance of the cuticle in postgenital fusion areas, and altered morphology of trichomes and pavement cells. We also found that DSO is induced by salt, abscisic acid, and wounding stresses and its loss of function results in plants that are highly susceptible to salt and display reduced root branching. Thus, DSO is not only essential for developmental plasticity but also plays a vital role in stress responses.

  5. Proteolipid Protein Is Required for Transport of Sirtuin 2 into CNS Myelin

    PubMed Central

    Werner, Hauke B.; Kuhlmann, Katja; Shen, Siming; Uecker, Marina; Schardt, Anke; Dimova, Kalina; Orfaniotou, Foteini; Dhaunchak, Ajit; Brinkmann, Bastian G.; Möbius, Wiebke; Guarente, Lenny; Casaccia-Bonnefil, Patrizia; Jahn, Olaf; Nave, Klaus-Armin

    2009-01-01

    Mice lacking the expression of proteolipid protein (PLP)/DM20 in oligodendrocytes provide a genuine model for spastic paraplegia (SPG-2). Their axons are well myelinated but exhibit impaired axonal transport and progressive degeneration, which is difficult to attribute to the absence of a single myelin protein. We hypothesized that secondary molecular changes in PLPnull myelin contribute to the loss of PLP/DM20-dependent neuroprotection and provide more insight into glia-axonal interactions in this disease model. By gel-based proteome analysis, we identified >160 proteins in purified myelin membranes, which allowed us to systematically monitor the CNS myelin proteome of adult PLPnull mice, before the onset of disease. We identified three proteins of the septin family to be reduced in abundance, but the nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase sirtuin 2 (SIRT2) was virtually absent. SIRT2 is expressed throughout the oligodendrocyte lineage, and immunoelectron microscopy revealed its association with myelin. Loss of SIRT2 in PLPnull was posttranscriptional, suggesting that PLP/DM20 is required for its transport into the myelin compartment. Because normal SIRT2 activity is controlled by the NAD+/NADH ratio, its function may be coupled to the axo-glial metabolism and the long-term support of axons by oligodendrocytes. PMID:17634366

  6. The minimal-ABC trees with B1-branches.

    PubMed

    Dimitrov, Darko; Du, Zhibin; Fonseca, Carlos M da

    2018-01-01

    The atom-bond connectivity index (or, for short, ABC index) is a molecular structure descriptor bridging chemistry to graph theory. It is probably the most studied topological index among all numerical parameters of a graph that characterize its topology. For a given graph G = (V, E), the ABC index of G is defined as [Formula: see text], where di denotes the degree of the vertex i, and ij is the edge incident to the vertices i and j. A combination of physicochemical and the ABC index properties are commonly used to foresee the bioactivity of different chemical composites. Additionally, the applicability of the ABC index in chemical thermodynamics and other areas of chemistry, such as in dendrimer nanostars, benzenoid systems, fluoranthene congeners, and phenylenes is well studied in the literature. While finding of the graphs with the greatest ABC-value is a straightforward assignment, the characterization of the tree(s) with minimal ABC index is a problem largely open and has recently given rise to numerous studies and conjectures. A B1-branch of a graph is a pendent path of order 2. In this paper, we provide an important step forward to the full characterization of these minimal trees. Namely, we show that a minimal-ABC tree contains neither 4 nor 3 B1-branches. The case when the number of B1-branches is 2 is also considered.

  7. ATP-binding cassette transporters and sterol O-acyltransferases interact at membrane microdomains to modulate sterol uptake and esterification.

    PubMed

    Gulati, Sonia; Balderes, Dina; Kim, Christine; Guo, Zhongmin A; Wilcox, Lisa; Area-Gomez, Estela; Snider, Jamie; Wolinski, Heimo; Stagljar, Igor; Granato, Juliana T; Ruggles, Kelly V; DeGiorgis, Joseph A; Kohlwein, Sepp D; Schon, Eric A; Sturley, Stephen L

    2015-11-01

    A key component of eukaryotic lipid homeostasis is the esterification of sterols with fatty acids by sterol O-acyltransferases (SOATs). The esterification reactions are allosterically activated by their sterol substrates, the majority of which accumulate at the plasma membrane. We demonstrate that in yeast, sterol transport from the plasma membrane to the site of esterification is associated with the physical interaction of the major SOAT, acyl-coenzyme A:cholesterol acyltransferase (ACAT)-related enzyme (Are)2p, with 2 plasma membrane ATP-binding cassette (ABC) transporters: Aus1p and Pdr11p. Are2p, Aus1p, and Pdr11p, unlike the minor acyltransferase, Are1p, colocalize to sterol and sphingolipid-enriched, detergent-resistant microdomains (DRMs). Deletion of either ABC transporter results in Are2p relocalization to detergent-soluble membrane domains and a significant decrease (53-36%) in esterification of exogenous sterol. Similarly, in murine tissues, the SOAT1/Acat1 enzyme and activity localize to DRMs. This subcellular localization is diminished upon deletion of murine ABC transporters, such as Abcg1, which itself is DRM associated. We propose that the close proximity of sterol esterification and transport proteins to each other combined with their residence in lipid-enriched membrane microdomains facilitates rapid, high-capacity sterol transport and esterification, obviating any requirement for soluble intermediary proteins. © FASEB.

  8. Identification of high-level functional/system requirements for future civil transports

    NASA Technical Reports Server (NTRS)

    Swink, Jay R.; Goins, Richard T.

    1992-01-01

    In order to accommodate the rapid growth in commercial aviation throughout the remainder of this century, the Federal Aviation Administration (FAA) is faced with a formidable challenge to upgrade and/or modernize the National Airspace System (NAS) without compromising safety or efficiency. A recurring theme in both the Aviation System Capital Investment Plan (CIP), which has replaced the NAS Plan, and the new FAA Plan for Research, Engineering, and Development (RE&D) rely on the application of new technologies and a greater use of automation. Identifying the high-level functional and system impacts of such modernization efforts on future civil transport operational requirements, particularly in terms of cockpit functionality and information transfer, was the primary objective of this project. The FAA planning documents for the NAS of the 2005 era and beyond were surveyed; major aircraft functional capabilities and system components required for such an operating environment were identified. A hierarchical structured analysis of the information processing and flows emanating from such functional/system components were conducted and the results documented in graphical form depicting the relationships between functions and systems.

  9. WD60/FAP163 is a dynein intermediate chain required for retrograde intraflagellar transport in cilia

    PubMed Central

    Patel-King, Ramila S.; Gilberti, Renée M.; Hom, Erik F. Y.; King, Stephen M.

    2013-01-01

    Retrograde intraflagellar transport (IFT) is required for assembly of cilia. We identify a Chlamydomonas flagellar protein (flagellar-associated protein 163 [FAP163]) as being closely related to the D1bIC(FAP133) intermediate chain (IC) of the dynein that powers this movement. Biochemical analysis revealed that FAP163 is present in the flagellar matrix and is actively trafficked by IFT. Furthermore, FAP163 copurified with D1bIC(FAP133) and the LC8 dynein light chain, indicating that it is an integral component of the retrograde IFT dynein. To assess the functional role of FAP163, we generated an RNA interference knockdown of the orthologous protein (WD60) in planaria. The Smed-wd60(RNAi) animals had a severe ciliary assembly defect that dramatically compromised whole-organism motility. Most cilia were present as short stubs that had accumulated large quantities of IFT particle–like material between the doublet microtubules and the membrane. The few remaining approximately full-length cilia had a chaotic beat with a frequency reduced from 24 to ∼10 Hz. Thus WD60/FAP163 is a dynein IC that is absolutely required for retrograde IFT and ciliary assembly. PMID:23864713

  10. 40 CFR 51.916 - What are the requirements for an Ozone Transport Region under the 8-hour NAAQS?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 2 2011-07-01 2011-07-01 false What are the requirements for an Ozone... IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.916 What are the requirements for an Ozone Transport Region under the 8-hour NAAQS? (a) In General...

  11. 40 CFR 51.916 - What are the requirements for an Ozone Transport Region under the 8-hour NAAQS?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 2 2012-07-01 2012-07-01 false What are the requirements for an Ozone... IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.916 What are the requirements for an Ozone Transport Region under the 8-hour NAAQS? (a) In General...

  12. 40 CFR 51.916 - What are the requirements for an Ozone Transport Region under the 8-hour NAAQS?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 2 2013-07-01 2013-07-01 false What are the requirements for an Ozone... IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.916 What are the requirements for an Ozone Transport Region under the 8-hour NAAQS? (a) In General...

  13. 40 CFR 51.916 - What are the requirements for an Ozone Transport Region under the 8-hour NAAQS?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false What are the requirements for an Ozone... IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.916 What are the requirements for an Ozone Transport Region under the 8-hour NAAQS? (a) In General...

  14. 40 CFR 51.916 - What are the requirements for an Ozone Transport Region under the 8-hour NAAQS?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 2 2014-07-01 2014-07-01 false What are the requirements for an Ozone... IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.916 What are the requirements for an Ozone Transport Region under the 8-hour NAAQS? (a) In General...

  15. 24 CFR 3280.903 - General requirements for designing the structure to withstand transportation shock and vibration.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... HOME CONSTRUCTION AND SAFETY STANDARDS Transportation § 3280.903 General requirements for designing the... manufactured home shall be designed, in terms of its structural, plumbing, mechanical and electrical systems... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false General requirements for designing...

  16. 40 CFR 52.184 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.184 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a) The owner and...

  17. 40 CFR 52.54 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.54 Section 52.54... FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and operator of each...

  18. 40 CFR 52.789 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.789 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  19. 40 CFR 52.984 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.984 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  20. 40 CFR 52.584 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.584 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  1. 40 CFR 52.840 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.840 Section 52...; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  2. 40 CFR 52.731 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.731 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  3. 40 CFR 52.840 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.840 Section 52...; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  4. 40 CFR 52.540 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.540 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a) The owner and...

  5. 40 CFR 52.984 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.984 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  6. 40 CFR 52.1882 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1882 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  7. 40 CFR 52.584 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.584 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  8. 40 CFR 52.440 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.440 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  9. 40 CFR 52.54 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.54 Section 52.54... FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and operator of each...

  10. 40 CFR 52.882 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.882 Section 52...; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  11. 40 CFR 52.1882 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1882 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  12. 40 CFR 52.440 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.440 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  13. 40 CFR 52.984 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.984 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  14. 40 CFR 52.984 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.984 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  15. 40 CFR 52.940 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.940 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  16. 40 CFR 52.789 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.789 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  17. 40 CFR 52.940 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.940 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  18. 40 CFR 52.984 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.984 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  19. 40 CFR 52.540 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.540 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a) The owner and...

  20. 40 CFR 52.940 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.940 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...