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Sample records for abc transporter gene

  1. ABC-B transporter genes in Dirofilaria immitis

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    Catherine Bourguinat

    2016-08-01

    Full Text Available 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.

  2. Functional analysis of the ATP-binding cassette (ABC transporter gene family of Tribolium castaneum

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    Broehan Gunnar

    2013-01-01

    Full Text Available Abstract Background The ATP-binding cassette (ABC transporters belong to a large superfamily of proteins that have important physiological functions in all living organisms. Most are integral membrane proteins that transport a broad spectrum of substrates across lipid membranes. In insects, ABC transporters are of special interest because of their role in insecticide resistance. Results We have identified 73 ABC transporter genes in the genome of T. castaneum, which group into eight subfamilies (ABCA-H. This coleopteran ABC family is significantly larger than those reported for insects in other taxonomic groups. Phylogenetic analysis revealed that this increase is due to gene expansion within a single clade of subfamily ABCC. We performed an RNA interference (RNAi screen to study the function of ABC transporters during development. In ten cases, injection of double-stranded RNA (dsRNA into larvae caused developmental phenotypes, which included growth arrest and localized melanization, eye pigmentation defects, abnormal cuticle formation, egg-laying and egg-hatching defects, and mortality due to abortive molting and desiccation. Some of the ABC transporters we studied in closer detail to examine their role in lipid, ecdysteroid and eye pigment transport. Conclusions The results from our study provide new insights into the physiological function of ABC transporters in T. castaneum, and may help to establish new target sites for insect control.

  3. Mitochondrial ABC transporters.

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    Lill, R; Kispal, G

    2001-01-01

    In contrast to bacteria, mitochondria contain only a few ATP binding cassette (ABC) transporters in their inner membrane. The known mitochondrial ABC proteins fall into two major classes that, in the yeast Saccharomyces cerevisiae, are represented by the half-transporter Atm1p and the two closely homologous proteins Mdl1p and Mdl2p. In humans two Atm1p orthologues (ABC7 and MTABC3) and two proteins homologous to Mdll/2p have been localized to mitochondria. The Atm1p-like proteins perform an important function in mitochondrial iron homeostasis and in the maturation of Fe/S proteins in the cytosol. Mutations in ABC7 are causative of hereditary X-linked sideroblastic anemia and cerebellar ataxia (XLSA/A). MTABC3 may be a candidate gene for the lethal neonatal syndrome. The function of the mitochondrial Mdl1/2p-like proteins is not clear at present with the notable exception of murine ABC-me that may transport intermediates of heme biosynthesis from the matrix to the cytosol in erythroid tissues.

  4. Thermodynamics of ABC transporters.

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    Zhang, Xuejun C; Han, Lei; Zhao, Yan

    2016-01-01

    ABC transporters form the largest of all transporter families, and their structural study has made tremendous progress over recent years. However, despite such advances, the precise mechanisms that determine the energy-coupling between ATP hydrolysis and the conformational changes following substrate binding remain to be elucidated. Here, we present our thermodynamic analysis for both ABC importers and exporters, and introduce the two new concepts of differential-binding energy and elastic conformational energy into the discussion. We hope that the structural analysis of ABC transporters will henceforth take thermodynamic aspects of transport mechanisms into account as well.

  5. Identification of ABC transporter genes of Fusarium graminearum with roles in azole tolerance and/or virulence.

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    Ghada Abou Ammar

    Full Text Available 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.

  6. Functional analysis of ABC transporter genes from Botrytis cinerea identifies BcatrB as a transporter of eugenol

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    Schoonbeek, H.; Nistelrooy, van J.G.M.; Waard, de M.A.

    2003-01-01

    The role of multiple ATP-binding cassette (ABC) and major facilitator superfamily (MFS) transporter genes from the plant pathogenic fungus Botrytis cinerea in protection against natural fungitoxic compounds was studied by expression analysis and phenotyping of gene-replacement mutants. The expressio

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

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    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

  8. Lysimachia foenum-graecum Herba Extract, a Novel Biopesticide, Inhibits ABC Transporter Genes and Mycelial Growth of Magnaporthe oryzae

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    Youngjin Lee

    2016-02-01

    Full Text Available To identify a novel biopesticide controlling rice blast disease caused by Magnaporthe oryzae, 700 plant extracts were evaluated for their inhibitory effects on mycelial growth of M. oryzae. The L. foenum-graecum Herba extract showed the lowest inhibition concentration (IC₅₀ of 39.28 μg/ml, which is lower than the IC₅₀ of blasticidin S (63.06 μg/ml, a conventional fungicide for rice blast disease. When treatments were combined, the IC₅₀ of blasticidin S was dramatically reduced to 10.67 μg/ml. Since ABC transporter genes are involved in fungicide resistance of many organisms, we performed RT-PCR to investigate the transcriptional changes of 40 ABC transporter family genes of M. oryzae treated with the plant extract, blasticidin S, and tetrandrine, a recognized ABC transporter inhibitor. Four ABC transporter genes were prominently activated by blasticidin S treatment, but were suppressed by combinational treatment of blasticidin S with the plant extract, or with tetrandrine that didn’t show cellular toxicity by itself in this study. Mycelial death was detected via confocal microscopy at 24 h after plant extract treatment. Finally, subsequent rice field study revealed that the plant extract had high control efficacy of 63.3% and should be considered a biopesticide for rice blast disease. These results showed that extract of L. foenum graecum Herba suppresses M. oryzae ABC transporter genes inducing mycelial death and therefore may be a potent novel biopesticide.

  9. The Schizosaccharomyces pombe mam1 gene encodes an ABC transporter mediating secretion of M-factor

    DEFF Research Database (Denmark)

    Christensen, P U; Davey, William John; Nielsen, O;

    1997-01-01

    In the fission yeast Schizosaccharomyces pombe, cells of opposite mating type communicate via diffusible peptide pheromones prior to mating. We have cloned the S. pombe mam1 gene, which encodes a 1336-amino acid protein belonging to the ATP-binding cassette (ABC) superfamily. The mam1 gene is onl...

  10. Characterization of a PDR type ABC transporter gene from wheat (Triticum aestivum L.)

    Institute of Scientific and Technical Information of China (English)

    SHANG Yi; XIAO Jin; MA LuLin; WANG HaiYan; QI ZengJun; CHEN PeiDu; LIU DaJun; WANG XiuE

    2009-01-01

    DON,as a virulence factor,plays an important role in the infection of Fusarium graminearum in wheat.The infection ability of F. graminearum depends on its capacity of producing DON. The production of DON by F. graminearum is significantly decreased in the wheat varieties with scab resistance. In this study,GeneChip analysis indicated that an EST encoding an ATP-binding cassette (ABC) transporter was up-regulated by 45 times in a wheat landrace Wangshuibai,which is resistant to DON accumulation.A pair of EST-derived primers were designed based on the EST sequence,and a clone was then isolated from a wheat genomic DNA TAC library. The TAC clone was sequenced using chromosome walking and gene prediction was conducted using Softberry. A cDNA clone of this gene was subsequently isolated from Wangshuibai induced by DON using gene-specific primers designed according to the untranslated sequence of the gene. The genome size of the gene is 7377 bp,consisting of 19 exons with coding sequences of 4308 bp. It encodes a protein with 1435 amino acid residues and the calculated molecular weight is about 161 kD. BLAST analysis indicated that the gene may belong to pleiotropic drug resistance (PDR) sub-family,and hence designated as TaPDR1 (Triticum aestivum pleiotropic drug resistance). TaPDR1 was located on chromosome 5A of wheat using nulliaomic-tetrasomic lines of Chinese Spring. TaPDR1 was up-regulated by induction of both DON and F. graminearum. Expression patterns of TaPDR1 were different in wild-type Wangshuibai and the fast-neutron induced Wangshuibai mutant lacking FHB1,a major QTL of FHB resistance and DON resistance in chromosome arm 3BS. These results suggested that TaPDR1 might be a candidate gene responsible for DON accumulation resistance. The expression profile showed that TaPDR1 expression was neither induced by hormones typically involved in biotic stress,such as JA and SA,nor by abiotic stresses,such as heat,cold,wounding and NaCI. However,TaPDR1 expression was

  11. Cloning of first abc transporter encoding gene from Trichoderma spp.and its expression during stress and mycoparasitism

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    Lanzuise S; Scala F; Del Sorbo G; Ruocco M; Scala V; Catapano L; Woo S; Ciliento R; Ferraioli S; Soriente I; Vinale F

    2004-01-01

    @@ Trichoderma in its natural environment competes for nutrient uptake and is required to protect itself from adverse natural toxic compounds, such as those produced by plants and other microbes in the soil community, or synthetic toxic compounds released human activity. One of the most important metabolic pathways for drug resistance and substrate uptake, both in prokaryotes and eukaryotes, is ATP dependent. The role of ABC transporter proteins in the biology of Trichoderma is still not known. We present the cloning of the first four ABC transporter genes (TABC1 , TABC2, TABC3,TABC4) in Trichoderma, and in particular T. atroviride P1, and the characterization of TABC2The complete sequence of this gene is 6535 bp, which includes a promoter of 1624 bp, a terminator of 642 bp and a coding region of 4264 bp. The promoter contains many of the potential transcription factor binding sites found in the 5' upstream region of the ech42 gene of T. atroviride P1. These included: heat shock factors (HSF), a nitrogen-regulating factor (Nit-2), a stress-response element (STRE), a GCR1 elements, and a Cre BP1 motif. Northern analysis and RT-PCR demonstrated that TABC2 is highly expressed when Trichoderma is subjected to nitrogen starvation, grown in the presence of culture filtrates of Botrytis cinerea, Rhizoctonia solani, and Pythium ultimum, or when N-acetylglucosamine is added to the substrate. TABC2 appears to be co-regulated with some CWDEencoding genes, suggesting that this is the first ABC transporter encoding gene involved in mycoparasitic events. It's role in the interaction of Trichoderma with fungal hosts or plants is being investigated by targeted gene disruption and overexpression.

  12. Variation and evolution of the ABC transporter genes ABCB1, ABCC1, ABCG2, ABCG5 and ABCG8: implication for pharmacogenetics and disease.

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    Silverton, Latoya; Dean, Michael; Moitra, Karobi

    2011-01-01

    The ATP-binding cassette (ABC) transporter genes are ubiquitous in the genomes of all vertebrates. Some of these transporters play a key role in xenobiotic defense and are endowed with the capacity to efflux harmful toxic substances. A major role in the evolution of the vertebrate ABC genes is played by gene duplication. Multiple gene duplication and deletion events have been identified in ABC genes, resulting in either gene birth or gene death indicating that the process of gene evolution is still ongoing in this group of transporters. Additionally, polymorphisms in these genes are linked to variations in expression, function, drug disposition and drug response. Single nucleotide polymorphisms in the ABC genes may be considered as markers of individual risk for adverse drug reactions or susceptibility to complex diseases as they can uniquely influence the quality and quantity of gene product. As the ABC genes continue to evolve, globalization will yield additional migration and racial admixtures that will have far reaching implications for the pharmacogenetics of this unique family of transporters in the context of human health.

  13. Isolation and Characterization of the Colletotrichum acutatum ABC Transporter CaABC1

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    Suyoung Kim

    2014-12-01

    Full Text Available Fungi tolerate exposure to various abiotic stresses, including cytotoxic compounds and fungicides, via their ATP-driven efflux pumps belonging to ATP-binding cassette (ABC transporters. To clarify the molecular basis of interaction between the fungus and various abiotic stresses including fungicides, we constructed a cDNA library from germinated conidia of Colletotrichum acutatum, a major anthracnose pathogen of pepper (Capsicum annum L.. Over 1,000 cDNA clones were sequenced, of which single clone exhibited significant nucleotide sequence homology to ABC transporter genes. We isolated three fosmid clones containing the C. acutatum ABC1 (CaABC1 gene in full-length from genomic DNA library screening. The CaABC1 gene consists of 4,059 bp transcript, predicting a 1,353-aa protein. The gene contains the typical ABC signature and Walker A and B motifs. The 5′-flanking region contains a CAAT motif, a TATA box, and a Kozak region. Phylogenetic and structural analysis suggested that the CaABC1 is a typical ABC transporter gene highly conserved in various fungal species, as well as in Chromista, Metazoans, and Viridiplantae. We also found that CaABC1 was up-regulated during conidiation and a minimal medium condition. Moreover, CaABC1 was induced in iprobenfos, kresoxim-methyl, thiophanate-methyl, and hygromycin B. These results demonstrate that CaABC1 is necessary for conidiation, abiotic stress, and various fungicide resistances. These results will provide the basis for further study on the function of ABC transporter genes in C. acutatum.

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

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    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.

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

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    Eleni Tani

    2016-04-01

    Full Text Available 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.

  16. Whole-transcriptome survey of the putative ATP-binding cassette (ABC) transporter family genes in the latex-producing laticifers of Hevea brasiliensis.

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    Zhiyi, Nie; Guijuan, Kang; Yu, Li; Longjun, Dai; Rizhong, Zeng

    2015-01-01

    The ATP-binding cassette (ABC) proteins or transporters constitute a large protein family in plants and are involved in many different cellular functions and processes, including solute transportation, channel regulation and molecular switches, etc. Through transcriptome sequencing, a transcriptome-wide survey and expression analysis of the ABC protein genes were carried out using the laticiferous latex from Hevea brasiliensis (rubber tree). A total of 46 putative ABC family proteins were identified in the H. brasiliensis latex. These consisted of 12 'full-size', 21 'half-size' and 13 other putative ABC proteins, and all of them showed strong conservation with their Arabidopsis thaliana counterparts. This study indicated that all eight plant ABC protein paralog subfamilies were identified in the H. brasiliensis latex, of which ABCB, ABCG and ABCI were the most abundant. Real-time quantitative reverse transcription-polymerase chain reaction assays demonstrated that gene expression of several latex ABC proteins was regulated by ethylene, jasmonic acid or bark tapping (a wound stress) stimulation, and that HbABCB15, HbABCB19, HbABCD1 and HbABCG21 responded most significantly of all to the abiotic stresses. The identification and expression analysis of the latex ABC family proteins could facilitate further investigation into their physiological involvement in latex metabolism and rubber biosynthesis by H. brasiliensis.

  17. Whole-transcriptome survey of the putative ATP-binding cassette (ABC transporter family genes in the latex-producing laticifers of Hevea brasiliensis.

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    Nie Zhiyi

    Full Text Available The ATP-binding cassette (ABC proteins or transporters constitute a large protein family in plants and are involved in many different cellular functions and processes, including solute transportation, channel regulation and molecular switches, etc. Through transcriptome sequencing, a transcriptome-wide survey and expression analysis of the ABC protein genes were carried out using the laticiferous latex from Hevea brasiliensis (rubber tree. A total of 46 putative ABC family proteins were identified in the H. brasiliensis latex. These consisted of 12 'full-size', 21 'half-size' and 13 other putative ABC proteins, and all of them showed strong conservation with their Arabidopsis thaliana counterparts. This study indicated that all eight plant ABC protein paralog subfamilies were identified in the H. brasiliensis latex, of which ABCB, ABCG and ABCI were the most abundant. Real-time quantitative reverse transcription-polymerase chain reaction assays demonstrated that gene expression of several latex ABC proteins was regulated by ethylene, jasmonic acid or bark tapping (a wound stress stimulation, and that HbABCB15, HbABCB19, HbABCD1 and HbABCG21 responded most significantly of all to the abiotic stresses. The identification and expression analysis of the latex ABC family proteins could facilitate further investigation into their physiological involvement in latex metabolism and rubber biosynthesis by H. brasiliensis.

  18. Antagonistic changes in sensitivity to antifungal drugs by mutations of an important ABC transporter gene in a fungal pathogen.

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    Wenjun Guan

    Full Text Available Fungal pathogens can be lethal, especially among immunocompromised populations, such as patients with AIDS and recipients of tissue transplantation or chemotherapy. Prolonged usage of antifungal reagents can lead to drug resistance and treatment failure. Understanding mechanisms that underlie drug resistance by pathogenic microorganisms is thus vital for dealing with this emerging issue. In this study, we show that dramatic sequence changes in PDR5, an ABC (ATP-binding cassette efflux transporter protein gene in an opportunistic fungal pathogen, caused the organism to become hypersensitive to azole, a widely used antifungal drug. Surprisingly, the same mutations conferred growth advantages to the organism on polyenes, which are also commonly used antimycotics. Our results indicate that Pdr5p might be important for ergosterol homeostasis. The observed remarkable sequence divergence in the PDR5 gene in yeast strain YJM789 may represent an interesting case of adaptive loss of gene function with significant clinical implications.

  19. Arbuscular mycorrhiza affects nickel translocation and expression of ABC transporter and metallothionein genes in Festuca arundinacea.

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    Shabani, Leila; Sabzalian, Mohammad R; Mostafavi pour, Sodabeh

    2016-01-01

    Mycorrhizal fungi are key microorganisms for enhancing phytoremediation of soils contaminated with heavy metals. In this study, the effects of the arbuscular mycorrhizal fungus (AMF) Funneliformis mosseae (=Glomus mosseae) on physiological and molecular mechanisms involved in the nickel (Ni) tolerance of tall fescue (Festuca arundinacea = Schedonorus arundinaceus) were investigated. Nickel addition had a pronounced negative effect on tall fescue growth and photosynthetic pigment contents, as well as on AMF colonization. Phosphorus content increased markedly in mycorrhizal plants (M) compared to non-inoculated (NM) ones. However, no significant difference was observed in root carbohydrate content between AMF-inoculated and non-inoculated plants. For both M and NM plants, Ni concentrations in shoots and roots increased according to the addition of the metal into soil, but inoculation with F. mosseae led to significantly lower Ni translocation from roots to the aboveground parts compared to non-inoculated plants. ABC transporter and metallothionein transcripts accumulated to considerably higher levels in tall fescue plants colonized by F. mosseae than in the corresponding non-mycorrhizal plants. These results highlight the importance of mycorrhizal colonization in alleviating Ni-induced stress by reducing Ni transport from roots to shoots of tall fescue plants.

  20. A novel gene amplification causes upregulation of the PatAB ABC transporter and fluoroquinolone resistance in Streptococcus pneumoniae.

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    Baylay, Alison J; Ivens, Alasdair; Piddock, Laura J V

    2015-01-01

    Overexpression of the ABC transporter genes patA and patB confers efflux-mediated fluoroquinolone resistance in Streptococcus pneumoniae and is also linked to pneumococcal stress responses. Although upregulation of patAB has been observed in many laboratory mutants and clinical isolates, the regulatory mechanisms controlling expression of these genes are unknown. In this study, we aimed to identify the cause of high-level constitutive overexpression of patAB in M184, a multidrug-resistant mutant of S. pneumoniae R6. Using a whole-genome transformation and sequencing approach, we identified a novel duplication of a 9.2-kb region of the M184 genome which included the patAB genes. This duplication did not affect growth and was semistable with a low segregation rate. The expression levels of patAB in M184 were much higher than those that could be fully explained by doubling of the gene dosage alone, and inactivation of the first copy of patA had no effect on multidrug resistance. Using a green fluorescent protein reporter system, increased patAB expression was ascribed to transcriptional read-through from a tRNA gene upstream of the second copy of patAB. This is the first report of a large genomic duplication causing antibiotic resistance in S. pneumoniae and also of a genomic duplication causing antibiotic resistance by a promoter switching mechanism.

  1. ABC transporters in Arthropods: genomic comparison and role in insecticide transport and resistance

    NARCIS (Netherlands)

    Dermauw, W.; Van Leeuwen, T.

    2014-01-01

    About a 100 years ago, the Drosophila white mutant marked the birth of Drosophila genetics. The white gene turned out to encode the first well studied ABC transporter in arthropods. The ABC gene family is now recognized as one of the largest transporter families in all kingdoms of life. The majority

  2. Role of ABC transporters in cancer chemotherapy

    Institute of Scientific and Technical Information of China (English)

    Yue-Li Sun; Atish Patel; Priyank Kumar; Zhe-Sheng Chen

    2012-01-01

    Multidrug resistance (MDR) in cancer cells can significantly attenuate the response to chemotherapy and increase the likelihood of mortality.The major mechanism involved in conferring MDR is the overexpression of ATP-binding cassette (ABC) transporters,which can increase efflux of drugs from cancer cells,thereby decreasing intracellular drug concentration.Modulators of ABC transporters have the potential to augment the efficacy of anticancer drugs.This editorial highlights some major findings related to ABC transporters and current strategies to overcome MDR.

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

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    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.

  4. Lateral gene transfer of an ABC transporter complex between major constituents of the human gut microbiome

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    Meehan Conor J

    2012-11-01

    Full Text Available Abstract Background Several links have been established between the human gut microbiome and conditions such as obesity and inflammatory bowel syndrome. This highlights the importance of understanding what properties of the gut microbiome can affect the health of the human host. Studies have been undertaken to determine the species composition of this microbiome and infer functional profiles associated with such host properties. However, lateral gene transfer (LGT between community members may result in misleading taxonomic attributions for the recipient organisms, thus making species-function links difficult to establish. Results We identified a peptides/nickel transport complex whose components differed in abundance based upon levels of host obesity, and assigned the encoded proteins to members of the microbial community. Each protein was assigned to several distinct taxonomic groups, with moderate levels of agreement observed among different proteins in the complex. Phylogenetic trees of these proteins produced clusters that differed greatly from taxonomic attributions and indicated that habitat-directed LGT of this complex is likely to have occurred, though not always between the same partners. Conclusions These findings demonstrate that certain membrane transport systems may be an important factor within an obese-associated gut microbiome and that such complexes may be acquired several times by different strains of the same species. Additionally, an example of individual proteins from different organisms being transferred into one operon was observed, potentially demonstrating a functional complex despite the donors of the subunits being taxonomically disparate. Our results also highlight the potential impact of habitat-directed LGT on the resident microbiota.

  5. Phylogenetic analysis of fungal ABC transporters

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    Driessen Arnold JM

    2010-03-01

    Full Text Available Abstract Background The superfamily of ABC proteins is among the largest known in nature. Its members are mainly, but not exclusively, involved in the transport of a broad range of substrates across biological membranes. Many contribute to multidrug resistance in microbial pathogens and cancer cells. The diversity of ABC proteins in fungi is comparable with those in multicellular animals, but so far fungal ABC proteins have barely been studied. Results We performed a phylogenetic analysis of the ABC proteins extracted from the genomes of 27 fungal species from 18 orders representing 5 fungal phyla thereby covering the most important groups. Our analysis demonstrated that some of the subfamilies of ABC proteins remained highly conserved in fungi, while others have undergone a remarkable group-specific diversification. Members of the various fungal phyla also differed significantly in the number of ABC proteins found in their genomes, which is especially reduced in the yeast S. cerevisiae and S. pombe. Conclusions Data obtained during our analysis should contribute to a better understanding of the diversity of the fungal ABC proteins and provide important clues about their possible biological functions.

  6. Transportomics: screening for substrates of ABC transporters in body fluids using vesicular transport assays.

    NARCIS (Netherlands)

    Krumpochova, P; Sapthu, S.; Brouwers, J.F.H.M.; de Haas, M.; de Vos, R.; Borst, P.; van de Wetering, K.

    2013-01-01

    ABSTRACT The ATP-binding cassette (ABC) genes encode the largest family of transmembrane proteins. ABC transporters translocate a wide variety of substrates across membranes, but their physiological function is often incompletely understood. We describe a new method to study the substrate spectrum o

  7. MgAtr7, a new type of ABC transporter from Mycosphaerella graminicola involved in iron homeostasis

    NARCIS (Netherlands)

    Zwiers, L.H.; Roohparvar, R.; Waard, de M.A.

    2007-01-01

    The ABC transporter-encoding gene MgAtr7 from the wheat pathogen Mycosphaerella graminicola was cloned based upon its high homology to ABC transporters involved in azole-fungicide sensitivity. Genomic and cDNA sequences indicated that the N-terminus of this ABC transporter contains a motif character

  8. ABC Transporters and the Alzheimer's Disease Enigma.

    Science.gov (United States)

    Wolf, Andrea; Bauer, Björn; Hartz, Anika M S

    2012-01-01

    Alzheimer's disease (AD) is considered the "disease of the twenty-first century." With a 10-fold increase in global incidence over the past 100 years, AD is now reaching epidemic proportions and by all projections, AD patient numbers will continue to rise. Despite intense research efforts, AD remains a mystery and effective therapies are still unavailable. This represents an unmet need resulting in clinical, social, and economic problems. Over the last decade, a new AD research focus has emerged: ATP-binding cassette (ABC) transporters. In this article, we provide an overview of the ABC transporters ABCA1, ABCA2, P-glycoprotein (ABCB1), MRP1 (ABCC1), and BCRP (ABCG2), all of which are expressed in the brain and have been implicated in AD. We summarize recent findings on the role of these five transporters in AD, and discuss their potential to serve as therapeutic targets.

  9. Host response transcriptional profiling reveals extracellular components and ABC (ATP-binding cassette transporters gene enrichment in typhoid fever-infected Nigerian children

    Directory of Open Access Journals (Sweden)

    Resau James H

    2011-09-01

    bacterial invasion. Distinct gene expression profiles can also be obtained from acute vs. convalescent phase during typhoid fever infection. We found novel down-regulation of ABC (ATP-binding cassette transporters genes such as ABCA7, ABCC5, and ABCD4 and ATPase activity as the highest enriched pathway. Conclusions We identified unique extracellular components and ABC transporters gene enrichments in typhoid fever-infected Nigerian children, which have never been reported. These enriched gene clusters may represent novel targeted pathways to improve diagnostic, prognostic, therapeutic and next-generation vaccine strategies for typhoid fever in Africa.

  10. TrmB, a sugar sensing regulator of ABC transporter genes in Pyrococcus furiosus exhibits dual promoter specificity and is controlled by different inducers.

    Science.gov (United States)

    Lee, Sung-Jae; Moulakakis, Christina; Koning, Sonja M; Hausner, Winfried; Thomm, Michael; Boos, Winfried

    2005-09-01

    TrmB is the transcriptional repressor for the gene cluster of the trehalose/maltose ABC transporter of the hyperthermophilic archaea Thermococcus litoralis and Pyrococcus furiosus (malE or TM operon), with maltose and trehalose acting as inducers. We found that TrmB (the protein is identical in both organisms) also regulated the transcription of genes encoding a separate maltodextrin ABC transporter in P. furiosus (mdxE or MD operon) with maltotriose, longer maltodextrins and sucrose acting as inducers, but not with maltose or trehalose. In vitro transcription of the malE and the mdxE operons was inhibited by TrmB binding to the different operator sequences. Inhibition of the TM operon was released by maltose and trehalose whereas inhibition of the MD operon was released by maltotriose and larger maltodextrins as well as by sucrose. Scanning mutagenesis of the TM operator revealed the role of the palindromic TACTNNNAGTA sequence for TrmB recognition. TrmB exhibits a broad spectrum of sugar-binding specificity, binding maltose, sucrose, maltotriose and trehalose in decreasing order of affinity, half-maximal binding occurring at 20, 60, 250 and 500 microM substrate concentration respectively. Of all substrates, only maltose shows sigmoidal binding characteristics with a Hill coefficient of 2. As measured by molecular sieve chromatography and cross-linking TrmB behaved as dimer in dilute buffer solution at room temperature. We conclude that TrmB acts as a bifunctional transcriptional regulator acting on two different promoters and being differentially controlled by binding to different sugars. We believe this to represent a novel strategy of prokaryotic transcription regulation.

  11. ABC transporter architecture and regulatory roles of accessory domains

    NARCIS (Netherlands)

    Biemans-Oldehinkel, E; Doeven, MK; Poolman, B

    2006-01-01

    We present an overview of the architecture of ATP-binding cassette (ABC) transporters and dissect the systems in core and accessory domains. The ABC transporter core is formed by the transmembrane domains (TMDs) and the nucleotide binding domains (NBDs) that constitute the actual translocator. The a

  12. The ABC transporter ABC40 encodes a phenylacetic acid export system in Penicillium chrysogenum

    OpenAIRE

    Weber, Stefan S.; Kovalchuk, Andriy; Bovenberg, Roe A. L.; Driessen, Arnold J. M.

    2012-01-01

    The filamentous fungus Penicillium chrysogenum is used for the industrial production of beta-lactam antibiotics. The pathway for beta-lactam biosynthesis has been resolved and involves the enzyme phenylacetic acid CoA ligase that is responsible for the CoA activation of the side chain precursor phenylacetic acid (PAA) that is used for the biosynthesis of penicillin G. To identify ABC transporters related to beta-lactam biosynthesis, we analyzed the expression of all 48 ABC transporters presen...

  13. Functional analysis of candidate ABC transporter proteins for sitosterol transport

    DEFF Research Database (Denmark)

    Albrecht, C; Elliott, J I; Sardini, A;

    2002-01-01

    implicated in lipid movement and expressed in tissues with a role in sterol synthesis and absorption, might also be involved in sitosterol transport. Transport by the multidrug resistance P-glycoprotein (P-gp; Abcb1), the multidrug resistance-associated protein (Mrp1; Abcc1), the breast cancer resistance...... the absorption of sitosterol and related molecules in the intestine by pumping them back into the lumen. Although mutations altering ABCG5 and ABCG8 are found in affected patients, no functional demonstration of sitosterol transport has been achieved. In this study, we investigated whether other ABC transporters...

  14. MDR-ABC transporters: biomarkers in rheumatoid arthritis.

    Science.gov (United States)

    Márki-Zay, János; Tauberné Jakab, Katalin; Szerémy, Péter; Krajcsi, Peter

    2013-01-01

    MDR-ABC transporters are widely expressed in cell types relevant to pathogenesis of rheumatoid arthritis. Many reports demonstrate the interaction of small molecule drugs with MDR-ABC transporters. Cell-based assays for disease relevant cell types can be easily gated and could reveal specific drug targets and may increase significance and utilisation of data in clinical practice. Many commonly used DMARDs (e.g. methotrexate, sulfasalazine, leflunomide/teriflunomide, hydroxychloroquine) are ABCG2 substrates. Consequently, the activity of this transporter in patients should be determined to understand the disposition and pharmacokinetics of the therapy. In addition, MDR-ABC transporters transport a variety of endobiotics that play important roles in cell proliferation, cell migration, angiogenesis and inflammation. Therefore, MDR-ABC transporters are important biomarkers in rheumatoid arthritis.

  15. ABC transporters and multidrug resistance in Aspergillus nidulans

    OpenAIRE

    ANDRADE, A. C.

    2000-01-01

    The term multidrug resistance (MDR) stands for simultaneous cellular resistance to chemically unrelated toxicants and is often associated with overproduction of multidrug-efflux proteins of the A TP- b inding- c assette (ABC) superfamily. The ABC transporters comprise a large and multifunctional family of proteins. Besides multidrug transporters, the superfamily includes proteins involved in transmembrane transport of various substances such as ions, amino acids, peptides, sugars, vitamins, s...

  16. Export of recombinant proteins in Escherichia coli using ABC transporter with an attached lipase ABC transporter recognition domain (LARD

    Directory of Open Access Journals (Sweden)

    Moon Yuseok

    2009-01-01

    Full Text Available Abstract Background ATP binding cassette (ABC transporter secretes the protein through inner and outer membranes simultaneously in gram negative bacteria. Thermostable lipase (TliA of Pseudomonas fluorescens SIK W1 is secreted through the ABC transporter. TliA has four glycine-rich repeats (GGXGXD in its C-terminus, which appear in many ABC transporter-secreted proteins. From a homology model of TliA derived from the structure of P. aeruginosa alkaline protease (AprA, lipase ABC transporter domains (LARDs were designed for the secretion of fusion proteins. Results The LARDs included four glycine-rich repeats comprising a β-roll structure, and were added to the C-terminus of test proteins. Either Pro-Gly linker or Factor Xa site was added between fusion proteins and LARDs. We attached different length of LARDs such as LARD0, LARD1 or whole TliA (the longest LARD to three types of proteins; green fluorescent protein (GFP, epidermal growth factor (EGF and cytoplasmic transduction peptide (CTP. These fusion proteins were expressed in Escherichia coli together with ABC transporter of either P. fluorescens or Erwinia chrysanthemi. Export of fusion proteins with the whole TliA through the ABC transporter was evident on the basis of lipase enzymatic activity. Upon supplementation of E. coli with ABC transporter, GFP-LARDs and EGF-LARDs were excreted into the culture supernatant. Conclusion The LARDs or whole TliA were attached to C-termini of model proteins and enabled the export of the model proteins such as GFP and EGF in E. coli supplemented with ABC transporter. These results open the possibility for the extracellular production of recombinant proteins in Pseudomonas using LARDs or TliA as a C-terminal signal sequence.

  17. ABC multidrug transporters in schistosomes and other parasitic flatworms.

    Science.gov (United States)

    Greenberg, Robert M

    2013-12-01

    Schistosomiasis, a neglected tropical disease affecting hundreds of millions, is caused by parasitic flatworms of the genus Schistosoma. Treatment and control of schistosomiasis relies almost exclusively on a single drug, praziquantel (PZQ), a dangerous situation for a disease of this magnitude. Though PZQ is highly effective overall, it has drawbacks, and reports of worms showing PZQ resistance, either induced in the laboratory or isolated from the field, are disconcerting. Multidrug transporters underlie multidrug resistance (MDR), a phenomenon in which resistance to a single drug is accompanied by unexpected cross-resistance to several structurally unrelated compounds. Some of the best studied multidrug transporters are members of the ancient and very large ATP-binding cassette (ABC) superfamily of efflux transporters. ABC multidrug transporters such as P-glycoprotein (Pgp; ABCB1) are also associated with drug resistance in parasites, including helminths such as schistosomes. In addition to their association with drug resistance, however, ABC transporters also function in a wide variety of physiological processes in metazoans. In this review, we examine recent studies that help define the role of schistosome ABC transporters in regulating drug susceptibility, and in normal schistosome physiology, including reproduction and excretory activity. We postulate that schistosome ABC transporters could be useful targets for compounds that enhance the effectiveness of current therapeutics as well as for agents that act as antischistosomals on their own.

  18. A Survey of the ATP-Binding Cassette (ABC Gene Superfamily in the Salmon Louse (Lepeophtheirus salmonis.

    Directory of Open Access Journals (Sweden)

    Greta Carmona-Antoñanzas

    Full Text Available Salmon lice, Lepeophtheirus salmonis (Krøyer, 1837, are fish ectoparasites causing significant economic damage in the mariculture of Atlantic salmon, Salmo salar Linnaeus, 1758. The control of L. salmonis at fish farms relies to a large extent on treatment with anti-parasitic drugs. A problem related to chemical control is the potential for development of resistance, which in L. salmonis is documented for a number of drug classes including organophosphates, pyrethroids and avermectins. The ATP-binding cassette (ABC gene superfamily is found in all biota and includes a range of drug efflux transporters that can confer drug resistance to cancers and pathogens. Furthermore, some ABC transporters are recognised to be involved in conferral of insecticide resistance. While a number of studies have investigated ABC transporters in L. salmonis, no systematic analysis of the ABC gene family exists for this species. This study presents a genome-wide survey of ABC genes in L. salmonis for which, ABC superfamily members were identified through homology searching of the L. salmonis genome. In addition, ABC proteins were identified in a reference transcriptome of the parasite generated by high-throughput RNA sequencing (RNA-seq of a multi-stage RNA library. Searches of both genome and transcriptome allowed the identification of a total of 33 genes / transcripts coding for ABC proteins, of which 3 were represented only in the genome and 4 only in the transcriptome. Eighteen sequences were assigned to ABC subfamilies known to contain drug transporters, i.e. subfamilies B (4 sequences, C (11 and G (2. The results suggest that the ABC gene family of L. salmonis possesses fewer members than recorded for other arthropods. The present survey of the L. salmonis ABC gene superfamily will provide the basis for further research into potential roles of ABC transporters in the toxicity of salmon delousing agents and as potential mechanisms of drug resistance.

  19. Coupled ATPase-adenylate kinase activity in ABC transporters

    Science.gov (United States)

    Kaur, Hundeep; Lakatos-Karoly, Andrea; Vogel, Ramona; Nöll, Anne; Tampé, Robert; Glaubitz, Clemens

    2016-01-01

    ATP-binding cassette (ABC) transporters, a superfamily of integral membrane proteins, catalyse the translocation of substrates across the cellular membrane by ATP hydrolysis. Here we demonstrate by nucleotide turnover and binding studies based on 31P solid-state NMR spectroscopy that the ABC exporter and lipid A flippase MsbA can couple ATP hydrolysis to an adenylate kinase activity, where ADP is converted into AMP and ATP. Single-point mutations reveal that both ATPase and adenylate kinase mechanisms are associated with the same conserved motifs of the nucleotide-binding domain. Based on these results, we propose a model for the coupled ATPase-adenylate kinase mechanism, involving the canonical and an additional nucleotide-binding site. We extend these findings to other prokaryotic ABC exporters, namely LmrA and TmrAB, suggesting that the coupled activities are a general feature of ABC exporters. PMID:28004795

  20. Lipid dependence of ABC transporter localization and function

    NARCIS (Netherlands)

    Klappe, Karin; Hummel, Ina; Hoekstra, Dick; Kok, Jan Willem

    2009-01-01

    Lipid rafts have been implicated in many cellular functions, including protein and lipid transport and signal transduction. ATP-binding cassette (ABC) transporters have also been localized in these membrane domains. In this review the evidence for this specific localization will be evaluated and dis

  1. ABC transporters of the wheat pathogen Mycosphaerella graminicola

    NARCIS (Netherlands)

    Zwiers, L.H.

    2002-01-01

     A TP- b inding c assette (ABC) transporters belong to one of the largest protein families known. They play a role in numerous vital processes in the cell and are characterised by their capacity to transport a broad variety of substrates, ranging fr

  2. Glycolysis inhibition inactivates ABC transporters to restore drug sensitivity in malignant cells.

    Directory of Open Access Journals (Sweden)

    Ayako Nakano

    Full Text Available Cancer cells eventually acquire drug resistance largely via the aberrant expression of ATP-binding cassette (ABC transporters, ATP-dependent efflux pumps. Because cancer cells produce ATP mostly through glycolysis, in the present study we explored the effects of inhibiting glycolysis on the ABC transporter function and drug sensitivity of malignant cells. Inhibition of glycolysis by 3-bromopyruvate (3BrPA suppressed ATP production in malignant cells, and restored the retention of daunorubicin or mitoxantrone in ABC transporter-expressing, RPMI8226 (ABCG2, KG-1 (ABCB1 and HepG2 cells (ABCB1 and ABCG2. Interestingly, although side population (SP cells isolated from RPMI8226 cells exhibited higher levels of glycolysis with an increased expression of genes involved in the glycolytic pathway, 3BrPA abolished Hoechst 33342 exclusion in SP cells. 3BrPA also disrupted clonogenic capacity in malignant cell lines including RPMI8226, KG-1, and HepG2. Furthermore, 3BrPA restored cytotoxic effects of daunorubicin and doxorubicin on KG-1 and RPMI8226 cells, and markedly suppressed subcutaneous tumor growth in combination with doxorubicin in RPMI8226-implanted mice. These results collectively suggest that the inhibition of glycolysis is able to overcome drug resistance in ABC transporter-expressing malignant cells through the inactivation of ABC transporters and impairment of SP cells with enhanced glycolysis as well as clonogenic cells.

  3. The Role of Eukaryotic and Prokaryotic ABC Transporter Family in Failure of Chemotherapy

    Science.gov (United States)

    El-Awady, Raafat; Saleh, Ekram; Hashim, Amna; Soliman, Nehal; Dallah, Alaa; Elrasheed, Azza; Elakraa, Ghada

    2017-01-01

    Over the years chemotherapy failure has been a vital research topic as researchers have been striving to discover reasons behind it. The extensive studies carried out on chemotherapeutic agents confirm that resistance to chemotherapy is a major reason for treatment failure. “Resistance to chemotherapy,” however, is a comprehensive phrase that refers to a variety of different mechanisms in which ATP-binding cassette (ABC) mediated efflux dominates. The ABC is one of the largest gene superfamily of transporters among both eukaryotes and prokaryotes; it represents a variety of genes that code for proteins, which perform countless functions, including drug efflux – a natural process that protects cells from foreign chemicals. Up to date, chemotherapy failure due to ABC drug efflux is an active research topic that continuously provides further evidence on multiple drug resistance (MDR), aiding scientists in tackling and overcoming this issue. This review focuses on drug resistance by ABC efflux transporters in human, viral, parasitic, fungal and bacterial cells and highlights the importance of the MDR permeability glycoprotein being the mutual ABC transporter among all studied organisms. Current developments and future directions to overcome this problem are also discussed. PMID:28119610

  4. ABC transporters from Botrytis cinerea in biotic and abiotic interactions

    NARCIS (Netherlands)

    Schoonbeek, H.

    2004-01-01

    Botrytis cinereais the causal agent of grey mould disease on a wide variety of crop plants. It is relatively insensitive to natural and synthetic fungitoxic compounds. This thesis describes how ABC (ATP-binding cassette) transporters contribute to protection by actively secre

  5. ABC transporters van Botrytis cinerea in biotische en abiotische interacties

    NARCIS (Netherlands)

    Schoonbeek, H.

    2005-01-01

    Op 29 november 2004 promoveerde Henk-jan Schoonbeek aan Wageningen Universiteit op het proefschrift getiteld 'ABC transporters from Botrytis cinerea in biotic and abiotic interactions'. Promotor was Prof. dr. ir. P.J.G.M. de Wit en co-promotor was dr.ir. M.A. de Waard, leerstoelgroep Fytopathologie,

  6. Placental ABC transporters, cellular toxicity and stress in pregnancy.

    Science.gov (United States)

    Aye, Irving L M H; Keelan, Jeffrey A

    2013-04-25

    The human placenta, in addition to its roles as a nutrient transfer and endocrine organ, functions as a selective barrier to protect the fetus against the harmful effects of exogenous and endogenous toxins. Members of the ATP-binding cassette (ABC) family of transport proteins limit the entry of xenobiotics into the fetal circulation via vectorial efflux from the placenta to the maternal circulation. Several members of the ABC family, including proteins from the ABCA, ABCB, ABCC and ABCG subfamilies, have been shown to be functional in the placenta with clinically significant roles in xenobiotic efflux. However, recent findings suggest that these transporters also protect placental tissue by preventing the cellular accumulation of cytotoxic compounds such as lipids, sterols and their derivatives. Such protective functions are likely to be particularly important in pregnancies complicated by inflammatory or oxidative stress, where the generation of toxic metabolites is enhanced. For example, ABC transporters have been shown to protect against the harmful effects of hypoxia and oxidative stress through increased expression and efflux of oxysterols and glutathione conjugated xenobiotics. However, this protective capacity may be diminished in response to the same stressors. Several studies in primary human trophoblast cells and animal models have demonstrated decreased expression and activity of placental ABC transporters with inflammatory, oxidative or metabolic stress. Several clinical studies in pregnancies complicated by inflammatory conditions such as preeclampsia and gestational diabetes support these findings, although further studies are required to determine the clinical relevance of the relationships between placental ABC transporter expression and activity, and placental function in stressed pregnancies. Such studies are necessary to fully understand the consequences of pregnancy disorders on placental function and viability in order to optimise pregnancy

  7. ABC Transporters and the Alzheimer’s Disease Enigma

    Directory of Open Access Journals (Sweden)

    Andrea eWolf

    2012-06-01

    Full Text Available Alzheimer’s disease (AD is considered the disease of the 21st century. With a 10-fold increase in global incidence over the past 100 years, AD is now reaching epidemic proportions and by all projections, AD patient numbers will continue to rise. Despite intense research efforts, AD remains a mystery and effective therapies are still unavailable. This represents an unmet need resulting in clinical, social, and economic problems.Over the last decade, a new AD research focus has emerged: ATP-binding cassette (ABC transporters. In this article, we provide an overview of the ABC transporters ABCA1, ABCA2, P-glycoprotein (ABCB1, Mrp1 (ABCC1 and BCRP (ABCG2, all of which are expressed in the brain and have been implicated in AD. We summarize recent findings on the role of these five transporters in AD, and discuss their potential to serve as therapeutic targets.

  8. Functional expression and characterization of plant ABC transporters in Xenopus laevis oocytes for transport engineering purposes

    DEFF Research Database (Denmark)

    Xu, Deyang; Veres, Dorottya; Belew, Zeinu Mussa

    2016-01-01

    suitable in transport engineering approaches, although their size and high number of introns make them notoriously difficult to clone. Here, we report a novel in planta “exon engineering” strategy for cloning of full-length coding sequence of ABC transporters followed by methods for biochemical......Transport engineering in bioengineering is aimed at efficient export of the final product to reduce toxicity and feedback inhibition and to increase yield. The ATP-binding cassette (ABC) transporters with their highly diverse substrate specificity and role in cellular efflux are potentially...... characterization of ABC exporters in Xenopus oocytes. Although the Xenopus oocyte expression system is particularly suitable for expression of membrane proteins and powerful in screening for novel transporter activity, only few examples of successful expression of ABC transporter has been reported. This raises...

  9. ABC transporter and metallothionein expression affected by NI and Epichloe endophyte infection in tall fescue.

    Science.gov (United States)

    Mirzahossini, Zahra; Shabani, Leila; Sabzalian, Mohammad R; Sharifi-Tehrani, Majid

    2015-10-01

    Epichloe endophytes are symbiotic fungi which unlike mycorrhiza grow within aerial parts of host plants. The fungi may increase host tolerance to both biotic and abiotic stresses. In this study, the effect of endophyte infection on growth and tolerance, carbohydrate contents and ABC (ABC transporter) and MET (metallothionein) expression in the leaves of tall fescue (Festuca arundinacea) plants cultivated in Ni polluted soil were evaluated. The endophyte infected (E+) and non-infected (E-) fescue plants were cultivated in soil under different Ni concentrations (30, 90 and 180mgkg(-1)). Growth parameters including root, shoot, total biomass, tiller number and total chlorophyll content of plants and H2O2 content of shoots were measured at the end of experiment. Ni translocation to the shoots, carbohydrate contents in roots and expression of ABC and MET of the leaves were also measured after 10 weeks of growth. Results demonstrated the beneficial effect of endophyte association on growth and Ni tolerance of tall fescue under Ni stress through an avoidance mechanism (reduction of Ni accumulation and translocation to the shoots). Endophyte infected plants showed less ABC and MET expression compared to the endophyte free plants. In endophyte free plants, H2O2 production had a significant positive correlation with genes expression, indicating that an increase in H2O2 might be involved in the up-regulation of ABC and MET under Ni stress.

  10. A multidrug ABC transporter with a taste for salt.

    Directory of Open Access Journals (Sweden)

    Saroj Velamakanni

    Full Text Available BACKGROUND: LmrA is a multidrug ATP-binding cassette (ABC transporter from Lactococcus lactis with no known physiological substrate, which can transport a wide range of chemotherapeutic agents and toxins from the cell. The protein can functionally replace the human homologue ABCB1 (also termed multidrug resistance P-glycoprotein MDR1 in lung fibroblast cells. Even though LmrA mediates ATP-dependent transport, it can use the proton-motive force to transport substrates, such as ethidium bromide, across the membrane by a reversible, H(+-dependent, secondary-active transport reaction. The mechanism and physiological context of this reaction are not known. METHODOLOGY/PRINCIPAL FINDINGS: We examined ion transport by LmrA in electrophysiological experiments and in transport studies using radioactive ions and fluorescent ion-selective probes. Here we show that LmrA itself can transport NaCl by a similar secondary-active mechanism as observed for ethidium bromide, by mediating apparent H(+-Na(+-Cl(- symport. Remarkably, LmrA activity significantly enhances survival of high-salt adapted lactococcal cells during ionic downshift. CONCLUSIONS/SIGNIFICANCE: The observations on H(+-Na(+-Cl(- co-transport substantiate earlier suggestions of H(+-coupled transport by LmrA, and indicate a novel link between the activity of LmrA and salt stress. Our findings demonstrate the relevance of investigations into the bioenergetics of substrate translocation by ABC transporters for our understanding of fundamental mechanisms in this superfamily. This study represents the first use of electrophysiological techniques to analyze substrate transport by a purified multidrug transporter.

  11. ABC transporter FtsABCD of Streptococcus pyogenes mediates uptake of ferric ferrichrome

    Directory of Open Access Journals (Sweden)

    McClure Michael J

    2005-10-01

    Full Text Available Abstract Background The Streptococcus pyogenes or Group A Streptococcus (GAS genome encodes three ABC transporters, namely, FtsABCD, MtsABC, and HtsABC, which share homology with iron transporters. MtsABC and HtsABC are believed to take up ferric (Fe3+ and manganese ions and heme, respectively, while the specificity of FtsABCD is unknown. Results Recombinant FtsB, the lipoprotein component of FtsABCD, was found to bind Fe3+ ferrichrome in a 1:1 stoichiometry. To investigate whether FtsABCD transports Fe3+ ferrichrome, GAS isogenic strains defective in lipoprotein gene ftsB and permease gene ftsC were generated, and the effects of the mutations on uptake of Fe3+ ferrichrome were examined using radioactive 55Fe3+ ferrichrome. FtsB was produced in the wild-type strain but not in the ftsB mutant, confirming the ftsB inactivation. While wild-type GAS took up 3.6 × 104 Fe3+ ferrichrome molecules per bacterium per min at room temperature, the ftsB and ftsC mutants did not have a detectable rate of Fe3+ ferrichrome uptake. The inactivation of ftsB or ftsC also decreased 55Fe3+ ferrichrome uptake by >90% under growth conditions in the case of limited uptake time. Complementation of the ftsB mutant with a plasmid carrying the ftsB gene restored FtsB production and 55Fe3+ ferrichrome association at higher levels compared with the parent strain. The inactivation of mtsA and htsA and Fe-restricted conditions enhanced the production of FtsB and Fe3+ ferrichrome uptake. Conclusion The FtsB protein bound Fe3+ ferrichrome, and inactivation of ftsB or ftsC, but not htsA or mtsA, diminished Fe3+ ferrichrome uptake, indicating that FtsABCD, but not HtsABC and MtsABC, is the transporter that takes up Fe3+ ferrichrome in GAS. Fe acquisition systems are virulence factors in many bacterial pathogens and are attractive vaccine candidates. The elucidation of the FtsABCD specificity advances the understanding of Fe acquisition processes in GAS and may help evaluating the

  12. A putative ABC transporter is involved in negative regulation of biofilm formation by Listeria monocytogenes

    DEFF Research Database (Denmark)

    Zhu, Xinna; Long, Fei; Chen, Yonghui

    2008-01-01

    Listeria monocytogenes may persist for long periods in food processing environments. In some instances, this may be due to aggregation or biofilm formation. To investigate the mechanism controlling biofilm formation in the food-borne pathogen L. monocytogenes, we characterized LM-49, a mutant...... with enhanced ability of biofilm-formation generated via transposon Tn917 mutagenesis of L. monocytogenes 4b G. In this mutant, a Tn917 insertion has disrupted the coding region of the gene encoding a putative ATP binding cassette (ABC) transporter permease identical to Lmof2365_1771 (a putative ABC......-transporter permease) presented in the sequenced strain L. monocytogenes str. 4b F2365. This disrupted gene, denoted lm.G_1771, encoded a protein with 10 transmembrane helixes. The revertant, LM-49RE, was obtained by replacing lm.G_1771::Tn917 with lm.G_1771 via homologous recombination. We found that LM-49RE formed...

  13. Gene amplification, ABC transporters and cytochrome P450s: unraveling the molecular basis of pyrethroid resistance in the dengue vector, Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    Vassiliki Bariami

    Full Text Available BACKGROUND: Pyrethroid insecticides are widely utilized in dengue control. However, the major vector, Aedes aegypti, is becoming increasingly resistant to these insecticides and this is impacting on the efficacy of control measures. The near complete transcriptome of two pyrethroid resistant populations from the Caribbean was examined to explore the molecular basis of this resistance. PRINCIPAL FINDINGS: Two previously described target site mutations, 1016I and 1534C were detected in pyrethroid resistant populations from Grand Cayman and Cuba. In addition between two and five per cent of the Ae. aegypti transcriptome was differentially expressed in the resistant populations compared to a laboratory susceptible population. Approximately 20 per cent of the genes over-expressed in resistant mosquitoes were up-regulated in both Caribbean populations (107 genes. Genes with putative monooxygenase activity were significantly over represented in the up-regulated subset, including five CYP9 P450 genes. Quantitative PCR was used to confirm the higher transcript levels of multiple cytochrome P450 genes from the CYP9J family and an ATP binding cassette transporter. Over expression of two genes, CYP9J26 and ABCB4, is due, at least in part, to gene amplification. SIGNIFICANCE: These results, and those from other studies, strongly suggest that increases in the amount of the CYP9J cytochrome P450s are an important mechanism of pyrethroid resistance in Ae. aegypti. The genetic redundancy resulting from the expansion of this gene family makes it unlikely that a single gene or mutation responsible for pyrethroid resistance will be identified in this mosquito species. However, the results from this study do pave the way for the development of new pyrethroid synergists and improved resistance diagnostics. The role of copy number polymorphisms in detoxification and transporter genes in providing protection against insecticide exposure requires further investigation.

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

    Science.gov (United States)

    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.

  15. TcyR regulates L-cystine uptake via the TcyABC transporter in Streptococcus mutans.

    Science.gov (United States)

    Kim, Jennifer; Senadheera, Dilani B; Lévesque, Céline M; Cvitkovitch, Dennis G

    2012-03-01

    Streptococcus mutans, a primary dental pathogen, has a remarkable capacity to scavenge nutrients from the oral biofilm for its survival. Cystine is an amino acid dimer formed by the oxidation of two cysteine residues that is required for optimal growth of S. mutans, which modulates l-cystine uptake via two recently identified transporters designated TcyABC and TcyDEFGH, which have not been fully characterized. Using a nonpolar tcyABC-deficient mutant (SmTcyABC), here, we report that l-cystine uptake is drastically diminished in the mutant, whereas its ability to grow is severely impaired under l-cystine starvation conditions, relative to wild type. A substrate competition assay showed that l-cystine uptake by the TcyABC transporter was strongly inhibited by dl-cystathionine and l-djenkolic acid and moderately inhibited by S-methyl-l-cysteine and l-cysteine. Using gene expression analysis, we observed that the tcyABC operon was upregulated under cystine starvation. TcyABC has been shown to be positively regulated by the LysR-type transcriptional regulator CysR. We identified another LysR-type transcriptional regulator that negatively regulates TcyABC with homology to the Bacillus subtilis YtlI regulator, which we termed TcyR. Our study enhances the understanding of l-cystine uptake in S. mutans, which allows survival and persistence of this pathogen in the oral biofilm.

  16. Differential contributions of five ABC transporters to mutidrug resistance, antioxidion and virulence of Beauveria bassiana, an entomopathogenic fungus.

    Science.gov (United States)

    Song, Ting-Ting; Zhao, Jing; Ying, Sheng-Hua; Feng, Ming-Guang

    2013-01-01

    Multidrug resistance (MDR) confers agrochemical compatibility to fungal cells-based mycoinsecticdes but mechanisms involved in MDR remain poorly understood for entomopathogenic fungi, which have been widely applied as biocontrol agents against arthropod pests. Here we characterized the functions of five ATP-binding cassette (ABC) transporters, which were classified to the subfamilies ABC-B (Mdr1), ABC-C (Mrp1) and ABC-G (Pdr1, Pdr2 and Pdr5) and selected from 54 full-size ABC proteins of Beauveria bassiana based on their main domain architecture, membrane topology and transcriptional responses to three antifungal inducers. Disruption of each transporter gene resulted in significant reduction in resistance to four to six of eight fungicides or antifungal drugs tested due to their differences in structure and function. Compared with wild-type and complemented (control) strains, disruption mutants of all the five transporter genes became significantly less tolerant to the oxidants menadione and H₂O₂ based on 22-41% and 10-31% reductions of their effective concentrations required for the suppression of 50% colony growth at 25°C. Under a standardized spray, the killing actions of ΔPdr5 and ΔMrp1 mutants against Spodoptera litura second-instar larvae were delayed by 59% and 33% respectively. However, no significant virulence change was observed in three other delta mutants. Taken together, the examined five ABC transporters contribute differentially to not only the fungal MDR but antioxidant capability, a phenotype rarely associated with ABC efflux pumps in previous reports; at least some of them are required for the full virulence of B. bassiana, thereby affecting the fungal biocontrol potential. Our results indicate that ABC pump-dependent MDR mechanisms exist in entomopathogenic fungi as do in yeasts and human and plant pathogenic fungi.

  17. Differential contributions of five ABC transporters to mutidrug resistance, antioxidion and virulence of Beauveria bassiana, an entomopathogenic fungus.

    Directory of Open Access Journals (Sweden)

    Ting-Ting Song

    Full Text Available Multidrug resistance (MDR confers agrochemical compatibility to fungal cells-based mycoinsecticdes but mechanisms involved in MDR remain poorly understood for entomopathogenic fungi, which have been widely applied as biocontrol agents against arthropod pests. Here we characterized the functions of five ATP-binding cassette (ABC transporters, which were classified to the subfamilies ABC-B (Mdr1, ABC-C (Mrp1 and ABC-G (Pdr1, Pdr2 and Pdr5 and selected from 54 full-size ABC proteins of Beauveria bassiana based on their main domain architecture, membrane topology and transcriptional responses to three antifungal inducers. Disruption of each transporter gene resulted in significant reduction in resistance to four to six of eight fungicides or antifungal drugs tested due to their differences in structure and function. Compared with wild-type and complemented (control strains, disruption mutants of all the five transporter genes became significantly less tolerant to the oxidants menadione and H₂O₂ based on 22-41% and 10-31% reductions of their effective concentrations required for the suppression of 50% colony growth at 25°C. Under a standardized spray, the killing actions of ΔPdr5 and ΔMrp1 mutants against Spodoptera litura second-instar larvae were delayed by 59% and 33% respectively. However, no significant virulence change was observed in three other delta mutants. Taken together, the examined five ABC transporters contribute differentially to not only the fungal MDR but antioxidant capability, a phenotype rarely associated with ABC efflux pumps in previous reports; at least some of them are required for the full virulence of B. bassiana, thereby affecting the fungal biocontrol potential. Our results indicate that ABC pump-dependent MDR mechanisms exist in entomopathogenic fungi as do in yeasts and human and plant pathogenic fungi.

  18. ABC- and SLC-Transporters in Murine and Bovine Mammary Epithelium

    DEFF Research Database (Denmark)

    Yagdiran, Yagmur; Oskarsson, Agneta; Knight, Christopher H.

    2016-01-01

    Some chemicals are ligands to efflux transporters which may result in high concentrations in milk. Limited knowledge is available on the influence of maternal exposure to chemicals on the expression and function of transporters in the lactating mammary gland. We determined gene expression of ABC...... and SLC transporters in murine mammary tissue of different gestation and lactation stages, in murine mammary cells (HC11) featuring resting and secreting phenotypes and in bovine mammary tissue and cells (BME-UV). Effects on transporter expression and function of the imidazole fungicide prochloraz......, previously reported toinfluence BCRP in mammary cells, was investigated on transporter expression and functionin the two cell lines. Transporters studied were BCRP, MDR1, MRP1, OATP1A5/OATP1A2,OCTN1 and OCT1. Gene expressions of BCRP and OCT1 in murine mammary glandswere increased during gestation...

  19. The maize glossy13 gene, cloned via BSR-Seq and Seq-walking encodes a putative ABC transporter required for the normal accumulation of epicuticular waxes.

    Directory of Open Access Journals (Sweden)

    Li Li

    Full Text Available Aerial plant surfaces are covered by epicuticular waxes that among other purposes serve to control water loss. Maize glossy mutants originally identified by their "glossy" phenotypes exhibit alterations in the accumulation of epicuticular waxes. By combining data from a BSR-Seq experiment and the newly developed Seq-Walking technology, GRMZM2G118243 was identified as a strong candidate for being the glossy13 gene. The finding that multiple EMS-induced alleles contain premature stop codons in GRMZM2G118243, and the one knockout allele of gl13, validates the hypothesis that gene GRMZM2G118243 is gl13. Consistent with this, GRMZM2G118243 is an ortholog of AtABCG32 (Arabidopsis thaliana, HvABCG31 (barley and OsABCG31 (rice, which encode ABCG subfamily transporters involved in the trans-membrane transport of various secondary metabolites. We therefore hypothesize that gl13 is involved in the transport of epicuticular waxes onto the surfaces of seedling leaves.

  20. Structural and mechanistic insights into ABC-type ECF transporters for vitamin uptake

    NARCIS (Netherlands)

    Dosz-Majsnerowska, Maria

    2014-01-01

    Dit proefschrift gaat over de relatie tussen de structuur en het mechanisme van ABC-type ECF transporters voor vitamines, uit de bacterie Lactococcus lactis. Energy-Coupling Factor (ECF) transporters vormen een subgroep van de ATP-binding cassette (ABC) transporters en zijn betrokken bij de opname v

  1. Mammalian P4-ATPases and ABC transporters and their role in phospholipid transport.

    Science.gov (United States)

    Coleman, Jonathan A; Quazi, Faraz; Molday, Robert S

    2013-03-01

    Transport of phospholipids across cell membranes plays a key role in a wide variety of biological processes. These include membrane biosynthesis, generation and maintenance of membrane asymmetry, cell and organelle shape determination, phagocytosis, vesicle trafficking, blood coagulation, lipid homeostasis, regulation of membrane protein function, apoptosis, etc. P(4)-ATPases and ATP binding cassette (ABC) transporters are the two principal classes of membrane proteins that actively transport phospholipids across cellular membranes. P(4)-ATPases utilize the energy from ATP hydrolysis to flip aminophospholipids from the exocytoplasmic (extracellular/lumen) to the cytoplasmic leaflet of cell membranes generating membrane lipid asymmetry and lipid imbalance which can induce membrane curvature. Many ABC transporters play crucial roles in lipid homeostasis by actively transporting phospholipids from the cytoplasmic to the exocytoplasmic leaflet of cell membranes or exporting phospholipids to protein acceptors or micelles. Recent studies indicate that some ABC proteins can also transport phospholipids in the opposite direction. The importance of P(4)-ATPases and ABC transporters is evident from the findings that mutations in many of these transporters are responsible for severe human genetic diseases linked to defective phospholipid transport. This article is part of a Special Issue entitled Phospholipids and Phospholipid Metabolism.

  2. Conformational dynamics in substrate-binding domains influences transport in the ABC importer GlnPQ

    NARCIS (Netherlands)

    Gouridis, Giorgos; Schuurman-Wolters, Geesina; Ploetz, Evelyn; Husada, Florence; Vietrov, Ruslan; de Boer, Marijn; Cordes, Thorben; Poolman, Bert

    2015-01-01

    The conformational dynamics in ABC transporters is largely elusive. The ABC importer GlnPQ from Lactococcus lactis has different covalently linked substrate-binding domains (SBDs), thus making it an excellent model system to elucidate the dynamics and role of the SBDs in transport. We demonstrate by

  3. Using mass spectrometry for identification of ABC transporters from Xanthomonas citri and mutants expressed in different growth conditions

    Energy Technology Data Exchange (ETDEWEB)

    Faria, J.N.; Balan, A. [Laboratorio Nacional de Biociencias - LNBIO, Campinas, SP (Brazil); Paes Leme, A.F. [Laboratorio Nacional de Luz Sincrotron (LNLS), Campinas, SP (Brazil)

    2012-07-01

    Full text: Xanthomonas citri is a phytopathogenic bacterium that infects citrus plants causing significant losses for the economy. In our group, we have focused on the identification and characterization of ABC transport proteins of this bacterium, in order to determinate their function for growth in vitro and in vivo, during infection. ABC transporters represent one of the largest families of proteins, which transport since small molecules as ions up to oligopeptides and sugars. In prokaryotic cells many works have reported the ABC transport function in pathogenesis, resistance, biofilm formation, infectivity and DNA repair, but until our knowledge, there is no data related to these transporters and X. citri. So, In order to determinate which transporters are expressed in X. citri, we started a proteomic analysis based on mono and bi-dimensional gels associated to mass spectrometry analyses. After growing X. citri and two different mutants deleted for ssuA and nitA genes in LB and minimum media, cellular extracts were obtained and used for preparation of mono and bi-dimensional gels. Seven bands covering the expected mass of ABC transporter components (20 kDa to 50 kDa) in SDS-PAGE were cut off the gel, treated with trypsin and submitted to the MS for protein identification. The results of 2D gels were good enough and will serve as a standard for development of similar experiments in large scale. (author)

  4. A vector system for ABC transporter-mediated secretion and purification of recombinant proteins in Pseudomonas species.

    Science.gov (United States)

    Ryu, Jaewook; Lee, Ukjin; Park, Jiye; Yoo, Do-Hyun; Ahn, Jung Hoon

    2015-03-01

    Pseudomonas fluorescens is an efficient platform for recombinant protein production. P. fluorescens has an ABC transporter secreting endogenous thermostable lipase (TliA) and protease, which can be exploited to transport recombinant proteins across the cell membrane. In this study, the expression vector pDART was constructed by inserting tliDEF, genes encoding the ABC transporter, along with the construct of the lipase ABC transporter recognition domain (LARD), into pDSK519, a widely used shuttle vector. When the gene for the target protein was inserted into the vector, the C-terminally fused LARD allowed it to be secreted through the ABC transporter into the extracellular medium. After secretion of the fused target protein, the LARD containing a hydrophobic C terminus enabled its purification through hydrophobic interaction chromatography (HIC) using a methyl-Sepharose column. Alkaline phosphatase (AP) and green fluorescent protein (GFP) were used to validate the expression, export, and purification of target proteins by the pDART system. Both proteins were secreted into the extracellular medium in P. fluorescens. In particular, AP was secreted in several Pseudomonas species with its enzymatic activity in extracellular media. Furthermore, purification of the target protein using HIC yielded some degree of AP and GFP purification, where AP was purified to almost a single product. The pDART system will provide greater convenience for the secretory production and purification of recombinant proteins in Gram-negative bacteria, such as Pseudomonas species.

  5. An ABC transporter mutation is correlated with insect resistance to Bacillus thuringiensis Cry1Ac toxin.

    Directory of Open Access Journals (Sweden)

    Linda J Gahan

    2010-12-01

    Full Text Available Transgenic crops producing insecticidal toxins from Bacillus thuringiensis (Bt are commercially successful in reducing pest damage, yet knowledge of resistance mechanisms that threaten their sustainability is incomplete. Insect resistance to the pore-forming Cry1Ac toxin is correlated with the loss of high-affinity, irreversible binding to the mid-gut membrane, but the genetic factors responsible for this change have been elusive. Mutations in a 12-cadherin-domain protein confer some Cry1Ac resistance but do not block this toxin binding in in vitro assays. We sought to identify mutations in other genes that might be responsible for the loss of binding. We employed a map-based cloning approach using a series of backcrosses with 1,060 progeny to identify a resistance gene in the cotton pest Heliothis virescens that segregated independently from the cadherin mutation. We found an inactivating mutation of the ABC transporter ABCC2 that is genetically linked to Cry1Ac resistance and is correlated with loss of Cry1Ac binding to membrane vesicles. ABC proteins are integral membrane proteins with many functions, including export of toxic molecules from the cell, but have not been implicated in the mode of action of Bt toxins before. The reduction in toxin binding due to the inactivating mutation suggests that ABCC2 is involved in membrane integration of the toxin pore. Our findings suggest that ABC proteins may play a key role in the mode of action of Bt toxins and that ABC protein mutations can confer high levels of resistance that could threaten the continued utilization of Bt-expressing crops. However, such mutations may impose a physiological cost on resistant insects, by reducing export of other toxins such as plant secondary compounds from the cell. This weakness could be exploited to manage this mechanism of Bt resistance in the field.

  6. Key Role of Human ABC Transporter ABCG2 in Photodynamic Therapy and Photodynamic Diagnosis

    Directory of Open Access Journals (Sweden)

    Toshihisa Ishikawa

    2010-01-01

    Full Text Available Accumulating evidence indicates that ATP-binding cassette (ABC transporter ABCG2 plays a key role in regulating the cellular accumulation of porphyrin derivatives in cancer cells and thereby affects the efficacy of photodynamic therapy and photodynamic diagnosis. The activity of porphyrin efflux can be affected by genetic polymorphisms in the ABCG2 gene. On the other hand, Nrf2, an NF-E2-related transcription factor, has been shown to be involved in oxidative stress-mediated induction of the ABCG2 gene. Since patients have demonstrated individual differences in their response to photodynamic therapy, transcriptional activation and/or genetic polymorphisms of the ABCG2 gene in cancer cells may affect patients' responses to photodynamic therapy. Protein kinase inhibitors, including imatinib mesylate and gefitinib, are suggested to potentially enhance the efficacy of photodynamic therapy by blocking ABCG2-mediated porphyrin efflux from cancer cells. This review article provides an overview on the role of human ABC transporter ABCG2 in photodynamic therapy and photodynamic diagnosis.

  7. ABC transporters and multidrug resistance in Aspergillus nidulans

    NARCIS (Netherlands)

    Andrade, A.C.

    2000-01-01

    The term multidrug resistance (MDR) stands for simultaneous cellular resistance to chemically unrelated toxicants and is often associated with overproduction of multidrug-efflux proteins of the A TP- b inding- c assette (ABC) superfamily. The ABC tr

  8. Crystal structure of ATP-binding subunit of an ABC transporter from Geobacillus kaustophilus.

    Science.gov (United States)

    Manjula, M; Pampa, K J; Kumar, S M; Mukherjee, S; Kunishima, N; Rangappa, K S; Lokanath, N K

    2015-03-27

    The ATP binding cassette (ABC) transporters, represent one of the largest superfamilies of primary transporters, which are very essential for various biological functions. The crystal structure of ATP-binding subunit of an ABC transporter from Geobacillus kaustophilus has been determined at 1.77 Å resolution. The crystal structure revealed that the protomer has two thick arms, (arm I and II), which resemble 'L' shape. The ATP-binding pocket is located close to the end of arm I. ATP molecule is docked into the active site of the protein. The dimeric crystal structure of ATP-binding subunit of ABC transporter from G. kaustophilus has been compared with the previously reported crystal structure of ATP-binding subunit of ABC transporter from Salmonella typhimurium.

  9. DDRT-PCR Analysis of Wheat Roots Under Iron-Deficient Condition and Differential Expression of ABC Gene

    Institute of Scientific and Technical Information of China (English)

    YIN Li-ping; LIU Wei-zhong; LIU Xiang-lin; HUANG Qin-ni; ZHANG Fu-suo

    2002-01-01

    Differential expression of gene in iron-efficient wheat cultivar Jing411 and iron-inefficient cul-tivar Sanshumai3 under iron-deficiency and iron-sufficiency conditions was revealed by differential display re-verse transcript PCR (DDRT-PCR) method. Northern blotting was carried out using ATP-binding transporter(ABC) cDNA obtained from DDRT-PCR products of the cuitivar Jing411 as probe. Our results suggested thatABC gene expression was suppressed under iron-deficiency condition.

  10. Mutations of the multi-drug resistance-associated protein ABC transporter gene 5 result in reduction of phytic acid in rice seeds.

    Science.gov (United States)

    Xu, Xiu-Hong; Zhao, Hai-Jun; Liu, Qing-Long; Frank, Thomas; Engel, Karl-Heinz; An, Gynheung; Shu, Qing-Yao

    2009-06-01

    Phytic acid (PA, myo-inositol 1,2,3,4,5,6-hexakisphosphate) is important to the nutritional quality of cereal and legume seeds. PA and its salts with micronutrient cations, such as iron and zinc, cannot be digested by humans and non-ruminant animals, and hence may affect food/feed nutritional value and cause P pollution of groundwater from animal waste. We previously developed a set of low phytic acid (LPA) rice mutant lines with the aim of increasing the nutritional quality of rice. Two of these lines, Os-lpa-XS110-2 (homozygous non-lethal) Os-lpa-XS110-3 (homozygous lethal), contain two mutant alleles of a LPA gene (hereafter XS-lpa2-1 and XS-lpa2-2, respectively). In this study, we mapped the XS-lpa2-1 gene to a region on chromosome 3 between microsatellite markers RM14360 and RM1332, where the rice orthologue (OsMRP5) of the maize lpa1 gene is located. Sequence analysis of the OsMRP5 gene revealed a single base pair change (C/G-T/A transition) in the sixth exon of XS-lpa2-1 and a 5-bp deletion in the first exon of XS-lpa2-2. OsMRP5 is expressed in both vegetative tissues and developing seeds, and the two mutations do not change the level of RNA transcription. A T-DNA insertion line, 4A-02500, in which OsMRP5 was disrupted, also showed the same high inorganic phosphorus phenotype as Os-lpa-XS110-3 and appeared to be homozygous lethal. PA is significantly reduced in Os-lpa-XS110-2 (~20%) and in 4A-02500 (~90%) seeds compared with their wild type lines, and no PA was detected in Os-lpa-XS110-3 using HPLC analysis. This evidence indicates that the OsMRP5 gene plays an important role in PA metabolism in rice seeds.

  11. Transcriptome-based identification of ABC transporters in the western tarnished plant bug Lygus hesperus.

    Directory of Open Access Journals (Sweden)

    J Joe Hull

    Full Text Available 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.

  12. An Arabidopsis thaliana ABC transporter that confers kanamycin resistance in transgenic plants does not endow resistance to Escherichia coli

    OpenAIRE

    Burris, Kellie; Mentewab, Ayalew; Ripp, Steven; Stewart, C. Neal

    2007-01-01

    Summary Concerns have been raised about potential horizontal gene transfer (HGT) of antibiotic resistance markers (ARMs) from transgenic plants to bacteria of medical and environmental importance. All ARMs used in transgenic plants have been bacterial in origin, but it has been recently shown that an Arabidopsis thaliana ABC transporter, Atwbc19, confers kanamycin resistance when overexpressed in transgenic plants. Atwbc19 was evaluated for its ability to transfer kanamycin resistance to Esch...

  13. The expression of superoxide dismutase (SOD) and a putative ABC transporter permease is inversely correlated during biofilm formation in Listeria monocytogenes 4b G

    Science.gov (United States)

    Little is known about the molecular basis of biofilm formation in Listeria monocytogenes. The superoxide dismutase (SOD) of the deletion mutant of lm.G_1771 gene, which encodes for a putative ABC_transporter permease, is highly expressed in biofilm. In this study, the sod gene deletion mutant delta ...

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

    Science.gov (United States)

    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.

  15. Systematic Identification of Rice ABC1 Gene Family and Its Response to Abiotic Stress

    Institute of Scientific and Technical Information of China (English)

    GAO Qing-song; ZHANG Dan; Xu Liang; XU Chen-wu

    2011-01-01

    Members of the activity of bc1 complex (ABC1) family are protein kinases that are widely found in prokaryotes and eukaryotes.Previous studies showed that several plant ABC1 genes participated in the abiotic stress response.Here,we present the systematic identification of rice and Arabidopsis ABC1 genes and the expression analysis of rice ABC1 genes.A total of 15 and 17 ABC1 genes from the rice and Arabidopsis genomes,respectively,were identified using a bioinformatics approach.Phylogenetic analyses of these proteins suggested that the divergence of this family had occurred and their main characteristics were established before the monocot-dicot split.Indeed,species-specific expansion contributed to the evolution of this family in rice and Arabidopsis after the monocot-dicot split.Intron/exon structure analysis indicated that most of the orthologous genes had similar exon sizes,but diverse intron sizes,and the rice genes contained larger introns,moreover,intron gain was an important event accompanying the recent evolution of the rice ABC1 family.Multiple sequence alignment revealed one conserved amino acid segment and four conserved amino acids in the ABC1 domain.Online subcellular localization predicted that nine rice ABC1 proteins were localized in chloroplasts.Real-time RT-PCR established that the rice ABC1 genes were primarily expressed in leaves and the expression could be modulated by a broad range of abiotic factors such as H2O2,abscisic acid,low temperature,drought,darkness and high salinity.These results reveal that the rice ABC1 gene family plays roles in the environmental stress response and specific biological processes of rice.

  16. Gene expression profiling of cytochromes P450, ABC transporters and their principal transcription factors in the amygdala and prefrontal cortex of alcoholics, smokers and drug-free controls by qRT-PCR.

    Science.gov (United States)

    Toselli, Francesca; de Waziers, Isabelle; Dutheil, Mary; Vincent, Marc; Wilce, Peter A; Dodd, Peter R; Beaune, Philippe; Loriot, Marie-Anne; Gillam, Elizabeth M J

    2015-01-01

    1. Ethanol consumption and smoking alter the expression of certain drug-metabolizing enzymes and transporters, potentially influencing the tissue-specific effects of xenobiotics. 2. Amygdala (AMG) and prefrontal cortex (PFC) are brain regions that modulate the effects of alcohol and smoking, yet little is known about the expression of cytochrome P450 enzymes (P450s) and ATP-binding cassette (ABC) transporters in these tissues. 3. Here, we describe the first study on the expression of 19 P450s, their redox partners, three ABC transporters and four related transcription factors in the AMG and PFC of smokers and alcoholics by quantitative RT-PCR. 4. CYP1A1, CYP1B1, CYP2B6, CYP2C8, CYP2C18, CYP2D6, CYP2E1, CYP2J2, CYP2S1, CYP2U1, CYP4X1, CYP46, adrenodoxin and NADPH-P450 reductase, ABCB1, ABCG2, ABCA1, and transcription factors aryl hydrocarbon receptor AhR and proliferator-activated receptor α were quantified in both areas. CYP2A6, CYP2C9, CYP2C19, CYP3A4, CYP3A5, adrenodoxin reductase and the nuclear receptors pregnane X receptor and constitutive androstane receptor were detected but below the limit of quantification. CYP1A2 and CYP2W1 were not detected. 5. Adrenodoxin expression was elevated in all case groups over controls, and smokers showed a trend toward higher CYP1A1 and CYP1B1 expression. 6. Our study shows that most xenobiotic-metabolizing P450s and associated redox partners, transporters and transcription factors are expressed in human AMG and PFC.

  17. Enterococcus faecalis uses a PTS permease and a host colonization-related ABC transporter for maltodextrin uptake.

    Science.gov (United States)

    Sauvageot, Nicolas; Mokhtari, Abdelhamid; Joyet, Philippe; Budin-Verneuil, Aurélie; Blancato, Víctor S; Repizo, Guillermo D; Henry, Céline; Pikis, Andreas; Thompson, John; Magni, Christian; Hartke, Axel; Deutscher, Josef

    2017-02-27

    Maltodextrin is a mixture of maltooligosaccharides, which are produced by the degradation of starch or glycogen. They are mostly composed of α-1,4- and some α-1,6- linked glucose residues. Genes presumed to code for the Enterococcus faecalis maltodextrin transporter were induced during enterococcal infection. We therefore carried out a detailed study of maltodextrin transport in this organism. Depending on their length (3 to 7 glucose residues), E. faecalis takes up maltodextrins either via MalT, a maltose-specific permease of the phosphoenolpyruvate (PEP):carbohydrate phosphotransferase system (PTS), or the ATP binding cassette (ABC) transporter MdxEFG/MsmX. Maltotriose, the smallest maltodextrin, is primarily transported by the PTS permease. A malT mutant therefore exhibits significantly reduced growth on maltose and maltotriose. The residual uptake of the trisaccharide is catalyzed by the ABC transporter, because a malT/mdxF double mutant no longer grows on maltotriose. The trisaccharide arrives as maltotriose-6″-P in the cell. MapP, which dephosphorylates maltose-6' -P, also releases Pi from maltotriose-6″-P. Maltotetraose and longer maltodextrins are mainly (or exclusively) taken up via the ABC transporter, because inactivation of the membrane protein MdxF prevents growth on maltotetraose and longer maltodextrins up to at least maltoheptaose. E. faecalis also utilizes panose and isopanose and we show for the first time that in contrast to maltotriose its two isomers are primarily transported via the ABC transporter. We confirm that maltodextrin utilization via MdxEFG/MsmX affects the colonization capacity of E. faecalis, because inactivation of mdxF significantly reduced enterococcal colonization and/or survival in kidneys and liver of mice after intraperitoneal infection.IMPORTANCE Infections by enterococci, major health-care associated pathogens, are difficult to treat due to their increasing resistance to clinically relevant antibiotics and new

  18. Evolution of mal ABC transporter operons in the Thermococcales and Thermotogales

    Directory of Open Access Journals (Sweden)

    Gogarten J Peter

    2008-01-01

    Full Text Available Abstract Background The mal genes that encode maltose transporters have undergone extensive lateral transfer among ancestors of the archaea Thermococcus litoralis and Pyrococcus furiosus. Bacterial hyperthermophiles of the order Thermotogales live among these archaea and so may have shared in these transfers. The genome sequence of Thermotoga maritima bears evidence of extensive acquisition of archaeal genes, so its ancestors clearly had the capacity to do so. We examined deep phylogenetic relationships among the mal genes of these hyperthermophiles and their close relatives to look for evidence of shared ancestry. Results We demonstrate that the two maltose ATP binding cassette (ABC transporter operons now found in Tc. litoralis and P. furiosus (termed mal and mdx genes, respectively are not closely related to one another. The Tc. litoralis and P. furiosus mal genes are most closely related to bacterial mal genes while their respective mdx genes are archaeal. The genes of the two mal operons in Tt. maritima are not related to genes in either of these archaeal operons. They are highly similar to one another and belong to a phylogenetic lineage that includes mal genes from the enteric bacteria. A unique domain of the enteric MalF membrane spanning proteins found also in these Thermotogales MalF homologs supports their relatively close relationship with these enteric proteins. Analyses of genome sequence data from other Thermotogales species, Fervidobacterium nodosum, Thermosipho melanesiensis, Thermotoga petrophila, Thermotoga lettingae, and Thermotoga neapolitana, revealed a third apparent mal operon, absent from the published genome sequence of Tt. maritima strain MSB8. This third operon, mal3, is more closely related to the Thermococcales' bacteria-derived mal genes than are mal1 and mal2. F. nodosum, Ts. melanesiensis, and Tt. lettingae have only one of the mal1-mal2 paralogs. The mal2 operon from an unknown species of Thermotoga appears to

  19. AztD, a Periplasmic Zinc Metallochaperone to an ATP-binding Cassette (ABC) Transporter System in Paracoccus denitrificans.

    Science.gov (United States)

    Handali, Melody; Roychowdhury, Hridindu; Neupane, Durga P; Yukl, Erik T

    2015-12-11

    Bacterial ATP-binding cassette (ABC) transporters of transition metals are essential for acquisition of necessary elements from the environment. A large number of Gram-negative bacteria, including human pathogens, have a fourth conserved gene of unknown function adjacent to the canonical permease, ATPase, and solute-binding protein (SBP) genes of the AztABC zinc transporter system. To assess the function of this putative accessory factor (AztD) from Paracoccus denitrificans, we have analyzed its transcriptional regulation, metal binding properties, and interaction with the SBP (AztC). Transcription of the aztD gene is significantly up-regulated under conditions of zinc starvation. Recombinantly expressed AztD purifies with slightly substoichiometric zinc from the periplasm of Escherichia coli and is capable of binding up to three zinc ions with high affinity. Size exclusion chromatography and a simple intrinsic fluorescence assay were used to determine that AztD as isolated is able to transfer bound zinc nearly quantitatively to apo-AztC. Transfer occurs through a direct, associative mechanism that prevents loss of metal to the solvent. These results indicate that AztD is a zinc chaperone to AztC and likely functions to maintain zinc homeostasis through interaction with the AztABC system. This work extends our understanding of periplasmic zinc trafficking and the function of chaperones in this process.

  20. ABC transporters as multidrug resistance mechanisms and the development of chemosensitizers for their reversal

    Directory of Open Access Journals (Sweden)

    Choi Cheol-Hee

    2005-10-01

    Full Text Available Abstract One of the major problems related with anticancer chemotherapy is resistance against anticancer drugs. The ATP-binding cassette (ABC transporters are a family of transporter proteins that are responsible for drug resistance and a low bioavailability of drugs by pumping a variety of drugs out cells at the expense of ATP hydrolysis. One strategy for reversal of the resistance of tumor cells expressing ABC transporters is combined use of anticancer drugs with chemosensitizers. In this review, the physiological functions and structures of ABC transporters, and the development of chemosensitizers are described focusing on well-known proteins including P-glycoprotein, multidrug resistance associated protein, and breast cancer resistance protein.

  1. Interactions of retinoids with the ABC transporters P-glycoprotein and Breast Cancer Resistance Protein

    Science.gov (United States)

    Tarapcsák, Szabolcs; Szalóki, Gábor; Telbisz, Ágnes; Gyöngy, Zsuzsanna; Matúz, Krisztina; Csősz, Éva; Nagy, Péter; Holb, Imre J.; Rühl, Ralph; Nagy, László; Szabó, Gábor; Goda, Katalin

    2017-01-01

    Retinoids – derivatives of vitamin A – are important cell permeant signaling molecules that regulate gene expression through activation of nuclear receptors. P-glycoprotein (Pgp) and ABCG2 are plasma membrane efflux transporters affecting the tissue distribution of numerous structurally unrelated lipophilic compounds. In the present work we aimed to study the interaction of the above ABC transporters with retinoid derivatives. We have found that 13-cis-retinoic acid, retinol and retinyl-acetate inhibited the Pgp and ABCG2 mediated substrate transport as well as the substrate stimulated ATPase activity of these transporters. Interestingly, 9-cis-retinoic acid and ATRA (all-trans retinoic acid), both are stereoisomers of 13-cis-retinoic acid, did not have any effect on the transporters’ activity. Our fluorescence anisotropy measurements revealed that 13-cis-retinoic acid, retinol and retinyl-acetate selectively increase the viscosity and packing density of the membrane. Thus, the mixed-type inhibition of both transporters by retinol and ABCG2 by 13-cis-retinoic acid may be the collective result of direct interactions of these retinoids with the substrate binding site(s) and of indirect interactions mediated by their membrane rigidifying effects. PMID:28145501

  2. Inhibition or knockdown of ABC transporters enhances susceptibility of adult and juvenile schistosomes to Praziquantel.

    Directory of Open Access Journals (Sweden)

    Ravi S Kasinathan

    2014-10-01

    Full Text Available Parasitic flatworms of the genus Schistosoma cause schistosomiasis, a neglected tropical disease that affects hundreds of millions. Treatment of schistosomiasis depends almost entirely on the drug praziquantel (PZQ. Though essential to treating and controlling schistosomiasis, a major limitation of PZQ is that it is not active against immature mammalian-stage schistosomes. Furthermore, there are reports of field isolates with heritable reductions in PZQ susceptibility, and researchers have selected for PZQ-resistant schistosomes in the laboratory. P-glycoprotein (Pgp; ABCB1 and other ATP binding cassette (ABC transporters remove a wide variety of toxins and xenobiotics from cells, and have been implicated in multidrug resistance (MDR. Changes in ABC transporter structure or expression levels are also associated with reduced drug susceptibility in parasitic helminths, including schistosomes. Here, we show that the activity of PZQ against schistosome adults and juveniles ex vivo is potentiated by co-administration of either the highly potent Pgp inhibitor tariquidar or combinations of inhibitors targeting multiple ABC multidrug transporters. Adult worms exposed to sublethal PZQ concentrations remain active, but co-administration of ABC transporter inhibitors results in complete loss of motility and disruption of the tegument. Notably, juvenile schistosomes (3-4 weeks post infection, normally refractory to 2 µM PZQ, become paralyzed when transporter inhibitors are added in combination with the PZQ. Experiments using the fluorescent PZQ derivative (R-PZQ-BODIPY are consistent with the transporter inhibitors increasing effective intraworm concentrations of PZQ. Adult worms in which expression of ABC transporters has been suppressed by RNA interference show increased responsiveness to PZQ and increased retention of (R-PZQ-BODIPY consistent with an important role for these proteins in setting levels of PZQ susceptibility. These results indicate that

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

    Science.gov (United States)

    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.

  4. On the role of the two extracytoplasmic substrate-binding domains in the ABC transporter OpuA

    NARCIS (Netherlands)

    Biemans-Oldehinkel, E; Poolman, B

    2003-01-01

    Members of two transporter families of the ATP-binding cassette (ABC) superfamily use two or even four extracytoplasmic substrate-binding domains (SBDs) for transport. We report on the role of the two SBDs in the translocation cycle of the ABC transporter OpuA from Lactococcus lactis. Heterooligomer

  5. Are lipid rafts involved in ABC transporter-mediated drug resistance of tumor cells?

    NARCIS (Netherlands)

    Kok, Jan Willem; Klappe, Karin; Hummel, Ina; Kroesen, Bart-Jan; Sietsma, Hannie; Meszaros, Peter

    2008-01-01

    Since their discovery, lipid rafts have been implicated in several cellular functions, including protein transport in polarized cells and signal transduction. Also in multidrug resistance lipid rafts may be important with regard to the localization of ATP-binding cassette (ABC) transporters in these

  6. PET tracers for imaging of ABC transporters at the blood-brain barrier : Principles and Strategies

    NARCIS (Netherlands)

    Luurtsema, Gert; Elsinga, Philip; Dierckx, Rudi; Boellaard, Ronald; van Waarde, Aren

    2016-01-01

    ABC transporters at the human blood-brain barrier protect the brain against the entry of harmful compounds but may also limit (or prevent) the cerebral entry of therapeutic drugs (e.g. anti-epileptics, antidepressants and antipsychotics). The efflux function of these transporters may be impaired in

  7. Functional Diversity of Tandem Substrate-Binding Domains in ABC Transporters from Pathogenic Bacteria

    NARCIS (Netherlands)

    Fulyani, Faizah; Schuurman-Wolters, Gea K.; Vujicic - Zagar, Andreja; Guskov, Albert; Slotboom, Dirk-Jan; Poolman, Bert

    2013-01-01

    The ATP-binding cassette (ABC) transporter GInPQ is an essential uptake system for amino acids in gram-positive pathogens and related nonpathogenic bacteria. The transporter has tandem substrate-binding domains (SBDs) fused to each transmembrane domain, giving rise to four SBDs per functional transp

  8. Structure and function of the universal stress protein TeaD and its role in regulating the ectoine transporter TeaABC of Halomonas elongata DSM 2581(T).

    Science.gov (United States)

    Schweikhard, Eva S; Kuhlmann, Sonja I; Kunte, Hans-Jörg; Grammann, Katrin; Ziegler, Christine M

    2010-03-16

    The halophilic bacterium Halomonas elongata takes up the compatible solute ectoine via the osmoregulated TRAP transporter TeaABC. A fourth orf (teaD) is located adjacent to the teaABC locus that encodes a putative universal stress protein (USP). By RT-PCR experiments we proved a cotranscription of teaD along with teaABC. Deletion of teaD resulted in an enhanced uptake for ectoine by the transporter TeaABC and hence a negative activity regulation of TeaABC by TeaD. A transcriptional regulation via DNA binding could be excluded. ATP binding to native TeaD was shown by HPLC, and the crystal structure of TeaD was solved in complex with ATP to a resolution of 1.9 A by molecular replacement. TeaD forms a dimer-dimer complex with one ATP molecule bound to each monomer, which has a Rossmann-like alpha/beta overall fold. Our results reveal an ATP-dependent oligomerization of TeaD, which might have a functional role in the regulatory mechanism of TeaD. USP-encoding orfs, which are located adjacent to genes encoding for TeaABC homologues, could be identified in several other organisms, and their physiological role in balancing the internal cellular ectoine pool is discussed.

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

    Science.gov (United States)

    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.

  10. Maltose and maltodextrin utilization by Listeria monocytogenes depend on an inducible ABC transporter which is repressed by glucose.

    Directory of Open Access Journals (Sweden)

    Shubha Gopal

    Full Text Available BACKGROUND: In the environment as well as in the vertebrate intestine, Listeriae have access to complex carbohydrates like maltodextrins. Bacterial exploitation of such compounds requires specific uptake and utilization systems. METHODOLOGY/PRINCIPAL FINDINGS: We could show that Listeria monocytogenes and other Listeria species contain genes/gene products with high homology to the maltodextrin ABC transporter and utilization system of B. subtilis. Mutant construction and growth tests revealed that the L. monocytogenes gene cluster was required for the efficient utilization of maltodextrins as well as maltose. The gene for the ATP binding protein of the transporter was located distant from the cluster. Transcription analyses demonstrated that the system was induced by maltose/maltodextrins and repressed by glucose. Its induction was dependent on a LacI type transcriptional regulator. Repression by glucose was independent of the catabolite control protein CcpA, but was relieved in a mutant defective for Hpr kinase/phosphorylase. CONCLUSIONS/SIGNIFICANCE: The data obtained show that in L. monocytogenes the uptake of maltodextrin and, in contrast to B. subtilis, also maltose is exclusively mediated by an ABC transporter. Furthermore, the results suggest that glucose repression of the uptake system possibly is by inducer exclusion, a mechanism not described so far in this organism.

  11. Two molybdate/tungstate ABC transporters that interact very differently with their substrate binding proteins.

    Science.gov (United States)

    Vigonsky, Elena; Ovcharenko, Elena; Lewinson, Oded

    2013-04-02

    In all kingdoms of life, ATP Binding Cassette (ABC) transporters participate in many physiological and pathological processes. Despite the diversity of their functions, they have been considered to operate by a largely conserved mechanism. One deviant is the vitamin B12 transporter BtuCD that has been shown to operate by a distinct mechanism. However, it is unknown if this deviation is an exotic example, perhaps arising from the nature of the transported moiety. Here we compared two ABC importers of identical substrate specificity (molybdate/tungstate), and find that their interactions with their substrate binding proteins are utterly different. One system forms a high-affinity, slow-dissociating complex that is destabilized by nucleotide and substrate binding. The other forms a low-affinity, transient complex that is stabilized by ligands. The results highlight significant mechanistic divergence among ABC transporters, even when they share the same substrate specificity. We propose that these differences are correlated with the different folds of the transmembrane domains of ABC transporters.

  12. Identification of a meningococcal L-glutamate ABC transporter operon essential for growth in low-sodium environments.

    Science.gov (United States)

    Monaco, Caterina; Talà, Adelfia; Spinosa, Maria Rita; Progida, Cinzia; De Nitto, Eleanna; Gaballo, Antonio; Bruni, Carmelo B; Bucci, Cecilia; Alifano, Pietro

    2006-03-01

    GdhR is a meningococcal transcriptional regulator that was previously shown to positively control the expression of gdhA, encoding the NADP-specific L-glutamate dehydrogenase (NADP-GDH), in response to the growth phase and/or to the carbon source. In this study we used reverse transcriptase-PCR-differential display (to identify additional GdhR-regulated genes. The results indicated that GdhR, in addition to NADP-GDH, controls the expression of a number of genes involved in glucose catabolism by the Entner-Doudoroff pathway and in l-glutamate import by an unknown ABC transport system. The genes encoding the putative periplasmic substrate-binding protein (NMB1963) and the permease (NMB1965) of the ABC transporter were genetically inactivated. Uptake experiments demonstrated an impairment of L-glutamate import in the NMB1965-defective mutant in the absence or in the presence of a low sodium ion concentration. In contrast, at a sodium ion concentration above 60 mM, the uptake defect disappeared, possibly because the activity of a sodium-driven secondary transporter became predominant. Indeed, the NMB1965-defective mutant was unable to grow at a low sodium ion concentration (60 mM). The same growth phenotype was observed in the NMB1963-defective mutant. Cell invasion and intracellular persistence assays and expression data during cell invasion provided evidence that the l-glutamate ABC transporter, tentatively named GltT, was critical for meningococcal adaptation in the low-sodium intracellular environment.

  13. Functional reconstitution and osmoregulatory properties of the ProU ABC transporter from Escherichia coli

    NARCIS (Netherlands)

    Gul, Nadia; Poolman, Bert

    2013-01-01

    The ATP-binding cassette (ABC) transporter ProU from Escherichia coli translocates a wide range of compatible solutes and contributes to the regulation of cell volume, which is particularly important when the osmolality of the environment fluctuates. We have purified the components of ProU, i.e., th

  14. Genetic variation in ABC transporter A1 contributes to HDL cholesterol in the general population

    DEFF Research Database (Denmark)

    Frikke-Schmidt, Ruth; Nordestgaard, Børge G; Jensen, Gorm B;

    2004-01-01

    Homozygosity for mutations in ABC transporter A1 (ABCA1) causes Tangier disease, a rare HDL-deficiency syndrome. Whether heterozygosity for genetic variation in ABCA1 also contributes to HDL cholesterol (HDL-C) levels in the general population is presently unclear. We determined whether mutations...

  15. Beauvericin counteracted multi-drug resistant Candida albicans by blocking ABC transporters

    DEFF Research Database (Denmark)

    Tong, Yaojun; Liu, Mei; Zhang, Yu

    2016-01-01

    screening and whole-cell based mechanism study, identified a natural product, beauvericin (BEA) as a drug efflux pump modulator, which can reverse the multi-drug resistant phenotype of Candida albicans by specifically blocking the ATP-binding cassette (ABC) transporters; meantime, BEA alone has fungicidal...

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

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharjee, Sourav, E-mail: sourav.bhattacharjee@wur.nl [Wageningen University, Laboratory of Organic Chemistry (Netherlands); Opstal, Edward J. van; Alink, Gerrit M. [Wageningen University, Division of Toxicology (Netherlands); Marcelis, Antonius T. M.; Zuilhof, Han [Wageningen University, Laboratory of Organic Chemistry (Netherlands); Rietjens, Ivonne M. C. M. [Wageningen University, Division of Toxicology (Netherlands)

    2013-06-15

    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 {approx}45 nm) and polystyrene nanoparticles (PSNPs/size {approx}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).

  17. Enantioselective Induction of a Glutathione-S-Transferase, a Glutathione Transporter and an ABC Transporter in Maize by Metolachlor and Its (S)-Isomer

    OpenAIRE

    Sen Pang; Zhaojin Ran; Zhiqian Liu; Xiaoyu Song; Liusheng Duan; Xuefeng Li; Chengju Wang

    2012-01-01

    The metabolism of chiral herbicides in plants remains poorly understood. Glutathione conjugation reactions are one of the principal mechanisms that plants utilize to detoxify xenobiotics. The induction by rac- and S-metolachlor of the expression of three genes, ZmGST27, ZmGT1 and ZmMRP1, encoding respectively a glutathione-S-transferase, a glutathione transporter and an ATP-binding cassette (ABC) transporter was studied in maize. The results demonstrate that the inducing effect of rac- and S-...

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

    Science.gov (United States)

    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.

  19. Estimation of Candida albicans ABC transporter behaviour in real-time via fluorescence

    Directory of Open Access Journals (Sweden)

    Joanna eSzczepaniak

    2015-12-01

    Full Text Available We present a fluorometric method for determining ABC transporter activity in the pathogenic fungus Candida albicans during different growth phases and in response to glucose. The carbocyanine dye diS-C3(3 was previously used to monitor plasma membrane potentials and test the influence of surface-active compounds in membrane polarization. We used diS-C3(3 to show changes in fluorescence kinetics that reflect changes in the activity of ABC transporters in C. albicans growth. Cdr1-GFP fluorescence, revealed that Cdr1p relocates to the inside of the cell after the early-log growth phase. Addition of glucose to the cell suspension resulted in Cdr1p transporter expression in the CDR2-knockout strain. We confirmed the diS-C3(3 results by standard RT-PCR and Western blotting.

  20. Conformational dynamics in substrate-binding domains influences transport in the ABC importer GlnPQ.

    Science.gov (United States)

    Gouridis, Giorgos; Schuurman-Wolters, Gea K; Ploetz, Evelyn; Husada, Florence; Vietrov, Ruslan; de Boer, Marijn; Cordes, Thorben; Poolman, Bert

    2015-01-01

    The conformational dynamics in ABC transporters is largely elusive. The ABC importer GlnPQ from Lactococcus lactis has different covalently linked substrate-binding domains (SBDs), thus making it an excellent model system to elucidate the dynamics and role of the SBDs in transport. We demonstrate by single-molecule spectroscopy that the two SBDs intrinsically transit from open to closed ligand-free conformation, and the proteins capture their amino acid ligands via an induced-fit mechanism. High-affinity ligands elicit transitions without changing the closed-state lifetime, whereas low-affinity ligands dramatically shorten it. We show that SBDs in the closed state compete for docking onto the translocator, but remarkably the effect is strongest without ligand. We find that the rate-determining steps depend on the SBD and the amino acid transported. We conclude that the lifetime of the closed conformation controls both SBD docking to the translocator and substrate release.

  1. Localization of the ATP-binding cassette (ABC transport proteins PfMRP1, PfMRP2, and PfMDR5 at the Plasmodium falciparum plasma membrane

    Directory of Open Access Journals (Sweden)

    Luty Adrian JF

    2009-08-01

    Full Text Available Abstract Background The spread of drug resistance has been a major obstacle to the control of malaria. The mechanisms underlying drug resistance in malaria seem to be complex and multigenic. The current literature on multiple drug resistance against anti-malarials has documented PfMDR1, an ATP-binding cassette (ABC protein, as an important determinant of resistance. In the Plasmodium falciparum genome, there are several ABC transporters some of which could be putative drug transporting proteins. In order to understand the molecular mechanisms underlying drug resistance, characterization of these transporters is essential. The aim of this study was to characterize and localize putative ABC transporters. Methods In the plasmoDB database, 16 members of the P. falciparum ABC family can be identified, 11 of which are putative transport proteins. A phylogenetic analysis of the aligned NBDs of the PfABC genes was performed. Antibodies against PfMRP1 (PfABCC1, PfMRP2 (PfABCC2, and PfMDR5 (PfABCB5 were generated, affinity purified and used in immunocytochemistry to localize the proteins in the asexual stages of the parasite. Results The ABC family members of P. falciparum were categorized into subfamilies. The ABC B subfamily was the largest and contained seven members. Other family members that could be involved in drug transport are PfABCC1, PfABCC2, PfABCG1, and PfABCI3. The expression and localization of three ABC transport proteins was determined. PfMRP1, PfMRP2, and PfMDR5 are localized to the plasma membrane in all asexual stages of the parasite. Conclusion In conclusion, 11 of the 16 ABC proteins in the P. falciparum genome are putative transport proteins, some of which might be involved in drug resistance. Moreover, it was demonstrated that three of these proteins are expressed on the parasite's plasma membrane.

  2. Identification and characterization of an iron ABC transporter operon in Gluconacetobacter diazotrophicus Pal 5.

    Science.gov (United States)

    Urzúa, Lucia Soto; Vázquez-Candanedo, Ada P; Sánchez-Espíndola, Adriana; Ramírez, Carlos Ávila; Baca, Beatriz E

    2013-06-01

    Gluconacetobacter diazotrophicus is a nitrogen-fixing bacterium and endophyte of sugarcane. We have cloned and sequenced the genes coding for the components of the iron ABC-type acquisition system of G. diazotrophicus. Sequence analysis revealed three ORFs, (feuA, feuB, and feuC) organized as an operon and encoding polypeptides of 346 (38 kDa), 342 (34.2 kDa), and 240 (26 kDa) amino acids, respectively. The deduced translation products of the feu operon showed similarity with a periplasmic solute-binding protein (FeuA), permease (FeuB), and ATPase (FeuC) involved in Fe transport. The role of FeuB in the survival of G. diazotrophicus under iron depletion was evaluated by comparing the ability of wild-type and FeuB-Km(R) -mutant strains in a medium without iron supplementation and in a medium containing 2, 2'-dipyridyl (DP). Growth of the mutant was affected in the medium containing DP. The operon was expressed at higher levels in cells depleted for iron than in those that contained the metal. A decrease in nitrogenase activity was observed with the FeuB-Km(R) -mutant strain that with the wild-type under iron deficiency conditions, suggesting that the Feu operon play role in Fe nutrition of G. diazotrophicus.

  3. Functionally Relevant Residues of Cdr1p: A Multidrug ABC Transporter of Human Pathogenic Candida albicans

    Directory of Open Access Journals (Sweden)

    Rajendra Prasad

    2011-01-01

    Full Text Available Reduced intracellular accumulation of drugs (due to rapid efflux mediated by the efflux pump proteins belonging to ABC (ATP Binding Cassette and MFS (Major Facilitators superfamily is one of the most common strategies adopted by multidrug resistance (MDR pathogenic yeasts. To combat MDR, it is essential to understand the structure and function of these transporters so that inhibitors/modulators to these can be developed. The sequence alignments of the ABC transporters reveal selective divergence within much conserved domains of Nucleotide-Binding Domains (NBDs which is unique to all fungal transporters. Recently, the role of conserved but divergent residues of Candida Drug Resistance 1 (CDR1, an ABC drug transporter of human pathogenic Candida albicans, has been examined with regard to ATP binding and hydrolysis. In this paper, we focus on some of the recent advances on the relevance of divergent and conserved amino acids of CaCdr1p and also discuss as to how drug interacts with Trans Membrane Domains (TMDs residues for its extrusion from MDR cells.

  4. The ABC family of multidrug transporters in microorganisms

    NARCIS (Netherlands)

    van Veen, H.W; Konings, W.N

    1998-01-01

    Multidrug transporters are membrane proteins that are able to expel a broad range of toxic molecules from the cell. In humans, the overexpression of the multidrug resistance P-glycoprotein (Pgp) and the multidrug resistance-associated protein MRP1 (MRP) is a principal cause of resistance of cancers

  5. Reciprocal Regulation of Pyoluteorin Production with Membrane Transporter Gene Expression in Pseudomonas fluorescens Pf-5

    OpenAIRE

    2005-01-01

    Pyoluteorin is a chlorinated polyketide antibiotic secreted by the rhizosphere bacterium Pseudomonas fluorescens Pf-5. Genes encoding enzymes and transcriptional regulators involved in pyoluteorin production are clustered in the genome of Pf-5. Sequence analysis of genes adjacent to the known pyoluteorin biosynthetic gene cluster revealed the presence of an ABC transporter system. We disrupted two putative ABC transporter genes by inserting transcriptional fusions to an ice nucleation reporte...

  6. Role of ABC transporters in fluoropyrimidine-based chemotherapy response.

    Science.gov (United States)

    Nies, Anne T; Magdy, Tarek; Schwab, Matthias; Zanger, Ulrich M

    2015-01-01

    Since over 50 years, 5-fluorouracil (5-FU) is in use as backbone of chemotherapy treatment regimens for a wide range of cancers including colon, breast, and head and neck carcinomas. However, drug resistance and severe toxicities such as mucositis, diarrhea, neutropenia, and vomiting in up to 40% of treated patients often lead to dose limitation or treatment discontinuation. Because the oral bioavailability of 5-FU is unpredictable and highly variable, 5-FU is commonly administered intravenously. To overcome medical complications and inconvenience associated with intravenous administration, the oral prodrugs capecitabine and tegafur have been developed. Both fluoropyrimidines are metabolically converted intracellularly to 5-FU, which then needs metabolic activation to exert its damaging activity on RNA and DNA. The low response rates of 10-15% of 5-FU monotherapy can be improved by combination regimens of infusional 5-FU and leucovorin together with oxaliplatin (FOLFOX) or irinotecan (FOLFIRI), thereby increasing response rates to 30-40%. The impact of metabolizing enzymes in the development of fluoropyrimidine toxicity and resistance has been studied in great detail. In addition, membrane drug transporters, which are critical determinants of intracellular drug concentrations, may play a role in occurrence of toxicity and development of resistance against fluoropyrimidine-based therapy as well. This review therefore summarizes current knowledge on the role of drug transporters with particular focus on ATP-binding cassette transporters in fluoropyrimidine-based chemotherapy response.

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

    Science.gov (United States)

    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.

  8. ABC transporters in anticancer drug transport – Less ons for Therapy, Drug Development and Delivery Systems

    Directory of Open Access Journals (Sweden)

    Suresh P.K

    2015-03-01

    Full Text Available The structural aspects as well as the classification of the ABC superfamily (the largest group of transmembrane proteins has been highlighted. Over-expression of one or more of these transporters, barring exceptions, can correlate with an increased drug resistance (the multidrug resistance phenotype. Hence, studying these proteins, using experimental and in silico approaches, has tremendous benefit for patient selection as well as stratification into “good” and “poor” drug responders. Further, the need to obtain a better insight into “intrinsic” and “extrinsic” mechanisms of resistance were reiterated upon, based on the relative recruitment of the different signal transduction molecules. The concept of the reversal of the MDR phenotype, has been discussed and extended in the context of combination therapy. This form of therapy involves the use of a cocktail of synthetic and biopharmaceutical drugs as well as nanotechnology-based approaches, for improvements in their pharmacokinetic (PK and pharmacodynamic (PD profile. Such strategies have targeted the heterogeneous cancer and cancer stem cells, signaling molecules, marker enzymes as well as the microenvironment for improved efficacy and safety as well as to minimize the chance of relapse

  9. Biochemical evidence for the presence of two α-glucoside ABC-transport systems in the hyperthermophilic archaeon Pyrococcus furiosus

    NARCIS (Netherlands)

    Koning, Sonja M.; Konings, Wil N.; Driessen, Arnold J.M.

    2002-01-01

    The hyperthermophilic archaeon Pyrococcus furiosus can utilize different carbohydrates, such as starch, maltose and trehalose. Uptake of α-glucosides is mediated by two different, binding protein-dependent, ATP-binding cassette (ABC)-type transport systems. The maltose transporter also transports tr

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

    Science.gov (United States)

    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.

  11. Reversal of resistance by GF120918 in cell lines expressing the ABC half-transporter, MXR

    DEFF Research Database (Denmark)

    de Bruin, M; Miyake, K; Litman, Thomas;

    1999-01-01

    assays, rhodamine and calcein efflux assays, and confocal microscopy in cell lines expressing different multidrug resistance transporters. At a concentration of 1 microM in cytotoxicity assays, GF120918 was able to sensitize both S1-B1-20, a subline expressing P-glycoprotein (Pgp), and S1-M1......The emergence of several newly identified members of the ABC transporter family has necessitated the development of antagonists that are able to inhibit more than one transporter. We assessed the ability of the chemosensitizer GF120918 to function as a multispecific antagonist using cytotoxicity......-80, a subline expressing a newly identified mitoxantrone transporter, MXR. GF120918 was ineffective in sensitizing MRP-overexpressing MCF-7 VP-16 cells to etoposide as determined by cytotoxicity studies. In flow cytometry experiments, rhodamine 123 efflux in S1-B1-20 cells was decreased at GF120918...

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    Natalia Brzozowska

    2016-05-01

    Full Text Available 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.

  14. Integrated analysis of residue coevolution and protein structure in ABC transporters.

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    Attila Gulyás-Kovács

    Full Text Available Intraprotein side chain contacts can couple the evolutionary process of amino acid substitution at one position to that at another. This coupling, known as residue coevolution, may vary in strength. Conserved contacts thus not only define 3-dimensional protein structure, but also indicate which residue-residue interactions are crucial to a protein's function. Therefore, prediction of strongly coevolving residue-pairs helps clarify molecular mechanisms underlying function. Previously, various coevolution detectors have been employed separately to predict these pairs purely from multiple sequence alignments, while disregarding available structural information. This study introduces an integrative framework that improves the accuracy of such predictions, relative to previous approaches, by combining multiple coevolution detectors and incorporating structural contact information. This framework is applied to the ABC-B and ABC-C transporter families, which include the drug exporter P-glycoprotein involved in multidrug resistance of cancer cells, as well as the CFTR chloride channel linked to cystic fibrosis disease. The predicted coevolving pairs are further analyzed based on conformational changes inferred from outward- and inward-facing transporter structures. The analysis suggests that some pairs coevolved to directly regulate conformational changes of the alternating-access transport mechanism, while others to stabilize rigid-body-like components of the protein structure. Moreover, some identified pairs correspond to residues previously implicated in cystic fibrosis.

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

    Science.gov (United States)

    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

  16. Distribution of AdeABC efflux system genes in genotypically diverse strains of clinical Acinetobacter baumannii.

    Science.gov (United States)

    Wieczorek, Piotr; Sacha, Paweł; Czaban, Sławomir; Hauschild, Tomasz; Ojdana, Dominika; Kowalczuk, Oksana; Milewski, Robert; Poniatowski, Bogusław; Nikliński, Jacek; Tryniszewska, Elżbieta

    2013-10-01

    Acinetobacter baumannii has emerged as a highly problematic hospital-associated pathogen. Different mechanisms contribute to the formation of multidrug resistance in A. baumannii, including the AdeABC efflux system. Distribution of the structural and regulatory genes encoding the AdeABC efflux system among genetically diverse clinical A. baumannii strains was achieved by using PCR and pulsed-field gel electrophoresis techniques. The distribution of adeABRS genes is extremely high among our A. baumannii strains, except the adeC gene. We have observed a large proportion of strains presenting multidrug-resistance phenotype for several years. The efflux pump could be an important mechanism in these strains in resistance to antibiotics.

  17. An asymmetric post-hydrolysis state of the ABC transporter ATPase dimer.

    Directory of Open Access Journals (Sweden)

    Anthony M George

    Full Text Available ABC transporters are a superfamily of enzyme pumps that hydrolyse ATP in exchange for translocation of substrates across cellular membranes. Architecturally, ABC transporters are a dimer of transmembrane domains coupled to a dimer of nucleotide binding domains (NBDs: the NBD dimer contains two ATP-binding sites at the intersubunit interface. A current controversy is whether the protomers of the NBD dimer separate during ATP hydrolysis cycling, or remain in constant contact. In order to investigate the ABC ATPase catalytic mechanism, MD simulations using the recent structure of the ADP+Pi-bound MJ0796 isolated NBD dimer were performed. In three independent simulations of the ADP+Pi/apo state, comprising a total of >0.5 µs, significant opening of the apo (empty active site was observed; occurring by way of intrasubunit rotations between the core and helical subdomains within both NBD monomers. In contrast, in three equivalent simulations of the ATP/apo state, the NBD dimer remained close to the crystal structure, and no opening of either active site occurred. The results thus showed allosteric coupling between the active sites, mediated by intrasubunit conformational changes. Opening of the apo site is exquisitely tuned to the nature of the ligand, and thus to the stage of the reaction cycle, in the opposite site. In addition to this, in also showing how one active site can open, sufficient to bind nucleotide, while the opposite site remains occluded and bound to the hydrolysis products ADP+Pi, the results are consistent with a Constant Contact Model. Conversely, they show how there may be no requirement for the NBD protomers to separate to complete the catalytic cycle.

  18. Ligand Binding and Crystal Structures of the Substrate-Binding Domain of the ABC Transporter OpuA

    NARCIS (Netherlands)

    Wolters, Justina C.; Berntsson, Ronnie P-A.; Gul, Nadia; Karasawa, Akira; Thunnissen, Andy-Mark W. H.; Slotboom, Dirk-Jan; Poolman, Bert

    2010-01-01

    The ABC transporter OpuA from Lactococcus lactis transports glycine betaine upon activation by threshold values of ionic strength. In this study, the ligand binding characteristics of purified OpuA in a detergent-solubilized state and of its substrate-binding domain produced as soluble protein (OpuA

  19. The role of ATP-binding cassette (ABC) transporters in pathogenesis and multidrug resistance of the wheat pathogen Mycosphaerella graminicola

    NARCIS (Netherlands)

    Stergiopoulos, I.

    2003-01-01

    ATP-binding cassette (ABC) transporters are membrane proteins that utilise the energy derived from the hydrolysis of ATP to drive the transport of compounds over biological membranes. They are members of one of the largest protein families to date, present in both pro- and eukaryotic

  20. Hypocholesterolemia, foam cell accumulation, but no atherosclerosis in mice lacking ABC-transporter A1 and scavenger receptor BI

    NARCIS (Netherlands)

    Zhao, Ying; Pennings, Marieke; Vrins, Carlos L. J.; Calpe-Berdiel, Laura; Hoekstra, Menno; Kruijt, J. Kar; Ottenhoff, Roelof; Hildebrand, Reeni B.; van der Sluis, Ronald; Jessup, Wendy; Le Goff, Wilfried; Chapman, M. John; Huby, Thierry; Groen, Albert K.; Van Berkel, Theo J. C.; Van Eck, Miranda

    2011-01-01

    High-density lipoprotein (HDL) mediated reverse cholesterol transport (RCT) is regarded to be crucial for prevention of foam cell formation and atherosclerosis. ABC-transporter A1 (ABCA1) and scavenger receptor BI (SR-BI) are involved in the biogenesis of HDL and the selective delivery of HDL choles

  1. Structure, biosynthesis, and function of bacterial capsular polysaccharides synthesized by ABC transporter-dependent pathways.

    Science.gov (United States)

    Willis, Lisa M; Whitfield, Chris

    2013-08-30

    Bacterial capsules are formed primarily from long-chain polysaccharides with repeat-unit structures. A given bacterial species can produce a range of capsular polysaccharides (CPSs) with different structures and these help distinguish isolates by serotyping, as is the case with Escherichia coli K antigens. Capsules are important virulence factors for many pathogens and this review focuses on CPSs synthesized via ATP-binding cassette (ABC) transporter-dependent processes in Gram-negative bacteria. Bacteria utilizing this pathway are often associated with urinary tract infections, septicemia, and meningitis, and E. coli and Neisseria meningitidis provide well-studied examples. CPSs from ABC transporter-dependent pathways are synthesized at the cytoplasmic face of the inner membrane through the concerted action of glycosyltransferases before being exported across the inner membrane and translocated to the cell surface. A hallmark of these CPSs is a conserved reducing terminal glycolipid composed of phosphatidylglycerol and a poly-3-deoxy-d-manno-oct-2-ulosonic acid (Kdo) linker. Recent discovery of the structure of this conserved lipid terminus provides new insights into the early steps in CPS biosynthesis.

  2. Insect Resistance to Bacillus thuringiensis Toxin Cry2Ab Is Conferred by Mutations in an ABC Transporter Subfamily A Protein.

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    Wee Tek Tay

    2015-11-01

    Full Text Available The use of conventional chemical insecticides and bacterial toxins to control lepidopteran pests of global agriculture has imposed significant selection pressure leading to the rapid evolution of insecticide resistance. Transgenic crops (e.g., cotton expressing the Bt Cry toxins are now used world wide to control these pests, including the highly polyphagous and invasive cotton bollworm Helicoverpa armigera. Since 2004, the Cry2Ab toxin has become widely used for controlling H. armigera, often used in combination with Cry1Ac to delay resistance evolution. Isolation of H. armigera and H. punctigera individuals heterozygous for Cry2Ab resistance in 2002 and 2004, respectively, allowed aspects of Cry2Ab resistance (level, fitness costs, genetic dominance, complementation tests to be characterised in both species. However, the gene identity and genetic changes conferring this resistance were unknown, as was the detailed Cry2Ab mode of action. No cross-resistance to Cry1Ac was observed in mutant lines. Biphasic linkage analysis of a Cry2Ab-resistant H. armigera family followed by exon-primed intron-crossing (EPIC marker mapping and candidate gene sequencing identified three independent resistance-associated INDEL mutations in an ATP-Binding Cassette (ABC transporter gene we named HaABCA2. A deletion mutation was also identified in the H. punctigera homolog from the resistant line. All mutations truncate the ABCA2 protein. Isolation of further Cry2Ab resistance alleles in the same gene from field H. armigera populations indicates unequal resistance allele frequencies and the potential for Bt resistance evolution. Identification of the gene involved in resistance as an ABC transporter of the A subfamily adds to the body of evidence on the crucial role this gene family plays in the mode of action of the Bt Cry toxins. The structural differences between the ABCA2, and that of the C subfamily required for Cry1Ac toxicity, indicate differences in the

  3. Insect Resistance to Bacillus thuringiensis Toxin Cry2Ab Is Conferred by Mutations in an ABC Transporter Subfamily A Protein

    Science.gov (United States)

    Tay, Wee Tek; Mahon, Rod J.; Heckel, David G.; Walsh, Thomas K.; Downes, Sharon; James, William J.; Lee, Sui-Fai; Reineke, Annette; Williams, Adam K.; Gordon, Karl H. J.

    2015-01-01

    The use of conventional chemical insecticides and bacterial toxins to control lepidopteran pests of global agriculture has imposed significant selection pressure leading to the rapid evolution of insecticide resistance. Transgenic crops (e.g., cotton) expressing the Bt Cry toxins are now used world wide to control these pests, including the highly polyphagous and invasive cotton bollworm Helicoverpa armigera. Since 2004, the Cry2Ab toxin has become widely used for controlling H. armigera, often used in combination with Cry1Ac to delay resistance evolution. Isolation of H. armigera and H. punctigera individuals heterozygous for Cry2Ab resistance in 2002 and 2004, respectively, allowed aspects of Cry2Ab resistance (level, fitness costs, genetic dominance, complementation tests) to be characterised in both species. However, the gene identity and genetic changes conferring this resistance were unknown, as was the detailed Cry2Ab mode of action. No cross-resistance to Cry1Ac was observed in mutant lines. Biphasic linkage analysis of a Cry2Ab-resistant H. armigera family followed by exon-primed intron-crossing (EPIC) marker mapping and candidate gene sequencing identified three independent resistance-associated INDEL mutations in an ATP-Binding Cassette (ABC) transporter gene we named HaABCA2. A deletion mutation was also identified in the H. punctigera homolog from the resistant line. All mutations truncate the ABCA2 protein. Isolation of further Cry2Ab resistance alleles in the same gene from field H. armigera populations indicates unequal resistance allele frequencies and the potential for Bt resistance evolution. Identification of the gene involved in resistance as an ABC transporter of the A subfamily adds to the body of evidence on the crucial role this gene family plays in the mode of action of the Bt Cry toxins. The structural differences between the ABCA2, and that of the C subfamily required for Cry1Ac toxicity, indicate differences in the detailed mode

  4. Cerebral ABC transporter-common mechanisms may modulate neurodegenerative diseases and depression in elderly subjects.

    Science.gov (United States)

    Pahnke, Jens; Fröhlich, Christina; Paarmann, Kristin; Krohn, Markus; Bogdanovic, Nenad; Årsland, Dag; Winblad, Bengt

    2014-11-01

    In elderly subjects, depression and dementia often coincide but the actual reason is currently unknown. Does a causal link exist or is it just a reactive effect of the knowledge to suffer from dementia? The ABC transporter superfamily may represent a causal link between these mental disorders. Since the transporters ABCB1 and ABCC1 have been discovered as major β-amyloid-exporting molecules at the blood-brain barrier and ABCC1 was found to be directly activated by St. John's wort (SJW), depression and dementia certainly share an important pathophysiologic link. It was recognized that herbal anti-depressant formulations made from SJW are at least as effective for the treatment of unipolar depression in old age as classical pharmacotherapy, while having fewer side effects (Cochrane reports, 2008). SJW is known to activate various metabolizing and transport systems in the body, with cytochrome P450 enzymes and ABC transporters being most important. Does the treatment of depression in elderly subjects using pharmacological compounds or phytomedical extracts target a mechanism that also accounts for peptide storage in Alzheimer's disease and perhaps other proteopathies of the brain? In this review we summarize recent data that point to a common mechanism and present the first promising causal treatment results of demented elderly subjects with distinct SJW extracts. Insufficient trans-barrier clearance may indeed present a common problem in all the proteopathies of the brain where toxic peptides are deposited in a location-specific manner. Thus, activation of efflux molecules holds promise for future treatment of this large group of devastating disorders.

  5. Screening of miRNA regulating ABCE1 gene in non-small-cell lung cancer%ABCE1基因在非小细胞肺癌内相关调节miRNA的筛选

    Institute of Scientific and Technical Information of China (English)

    田野; 刘思洋; 许辉; 姜文军; 赵希彤; 王晴; 田大力

    2015-01-01

    Objective To screen the miRNAs regulating ATP-binding cassette transporter E1(ABCE1) gene in non-small-cell lung cancer, and explore new strategies in lung cancer diagnosis and therapy. Methods The 20 patients with non-small-cell lung cancer(11 squamous cell carcinoma and 9 adenocarcinoma) were enrolled, included 13 males and 7 females, which aged 45-73 years old with mean age of 62.9 years old. Bioinformatics was used to predict the miRNAs regulated ABCE1 gene;statistical analysis was then done to screen out the purpose miRNA by real-time quantitative PCR(RT-Q-PCR) and detected miRNAs and ABCE1 mRNA and protein. Results The result of bioinformatics software predicted that seven miRNAs had highest possibility to regulate ABCE1 gene, which were miR-29a/b/c, miR-135a/b, miR-203 and miR-141. The expression of miR-29a/b/c, miR-135a, miR-203, especially miR-135a and miR-29c in carcinoma tissues, compared to those in pericarcinomatous tissues experienced decrease to different degrees, while the expression of mRNA and protein of ABCE1 increased in carcinoma tissues ( P < 0.05). Moreover, there appeared to be negative correlation between miR-135a and ABCE1 in lung cancer tissues(r=-0.665,P=0.001). Conclusion It is demonstrated that the miR-135a negatively regulates ABCE1 gene, and the combination of them might be the new target for diagnosis and treatment of non-small-cell lung cancer.%目的:筛选ATP结合盒E1(ABCE1)基因的相关调节miRNA,为诊治肺癌提供新思路。方法选取20例非小细胞肺癌患者,其中男性13例,女性7例;年龄45~73岁,平均年龄62.9岁。鳞癌11例,腺癌9例。应用生物信息学预测ABCE1基因上游的miRNA,通过实时定量聚合酶链反应(RT-Q-PCR)及免疫组织化学方法,对标本非小细胞癌组织和癌旁组织进行检测,并进行统计学分析,从中筛选出目的miRNA。结果生物信息软件预测7个最有可能调节 ABCE1基因的miRNA,分别为miR-29a

  6. PatA and PatB form a functional heterodimeric ABC multidrug efflux transporter responsible for the resistance of Streptococcus pneumoniae to fluoroquinolones.

    Science.gov (United States)

    Boncoeur, Emilie; Durmort, Claire; Bernay, Benoît; Ebel, Christine; Di Guilmi, Anne Marie; Croizé, Jacques; Vernet, Thierry; Jault, Jean-Michel

    2012-10-02

    All bacterial multidrug ABC transporters have been shown to work as either homodimers or heterodimers. Two possibly linked genes, patA and patB from Streptococcus pneumococcus, that encode half-ABC transporters have been shown previously to be involved in fluoroquinolone resistance. We showed that the ΔpatA, ΔpatB, or ΔpatA/ΔpatB mutant strains were more sensitive to unstructurally related compounds, i.e., ethidium bromide or fluoroquinolones, than the wild-type R6 strain. Inside-out vesicles prepared from Escherichia coli expressing PatA and/or PatB transported Hoechst 33342, a classical substrate of multidrug transporters, only when both PatA and PatB were coexpressed. This transport was inhibited either by orthovanadate or by reserpine, and mutation of the conserved Walker A lysine residue of either PatA or PatB fully abrogated Hoechst 33342 transport. PatA, PatB, and the PatA/PatB heterodimer were purified from detergent-solubilized E. coli membrane preparations. Protein dimers were identified in all cases, albeit in different proportions. In contrast to the PatA/PatB heterodimers, homodimers of PatA or PatB failed to show a vanadate-sensitive ATPase activity. Thus, PatA and PatB need to interact together to make a functional drug efflux transporter, and they work only as heterodimers.

  7. The ABC transporter ATR1 is necessary for efflux of the toxin cercosporin in the fungus Cercospora nicotianae.

    Science.gov (United States)

    Amnuaykanjanasin, Alongkorn; Daub, Margaret E

    2009-02-01

    The Cercospora nicotianae mutant deficient for the CRG1 transcription factor has marked reductions in both resistance and biosynthesis of the toxin cercosporin. We cloned and sequenced full-length copies of two genes, ATR1 and CnCFP, previously identified from a subtractive library between the wild type (WT) and a crg1 mutant. ATR1 is an ABC transporter gene and has an open reading frame (ORF) of 4368bp with one intron. CnCFP encodes a MFS transporter with homology to Cercospora kikuchii CFP, previously implicated in cercosporin export, and has an ORF of 1975bp with three introns. Disruption of ATR1 indicated atr1-null mutants had dramatic reductions in cercosporin production (25% and 20% of WT levels) in solid and liquid cultures, respectively. The ATR1 disruptants also showed moderately higher sensitivity to cercosporin. Constitutive expression of ATR1 in the crg1 mutant restored cercosporin biosynthesis and moderately increased resistance. In contrast, CnCFP overexpression in the mutant did not restore toxin production, however, it moderately enhanced toxin resistance. The results together indicate ATR1 acts as a cercosporin efflux pump in this fungus and plays a partial role in resistance.

  8. 1.55 Å Structure of the Ectoine Binding Protein TeaA of the Osmoregulated TRAP-Transporter TeaABC from Halomonas elongata

    NARCIS (Netherlands)

    Kuhlmann, Sonja I.; Terwisscha van Scheltinga, Anke C.; Bienert, Ralf; Kunte, Hans-Jörg; Ziegler, Christine

    2008-01-01

    TeaABC from the moderate halophilic bacterium Halomonas elongata belongs to the tripartite ATP-independent periplasmic transporters (TRAP-T), a family of secondary transporters functioning in conjunction with periplasmic substrate binding proteins. TeaABC facilitates the uptake of the compatible sol

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

    DEFF Research Database (Denmark)

    Andersen, Vibeke; Svenningsen, Katrine; Almind Knudsen, Lina;

    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....../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...... 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...

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

    Science.gov (United States)

    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.

  11. Genetic variation in ABC transporter A1 contributes to HDL cholesterol in the general population

    DEFF Research Database (Denmark)

    Frikke-Schmidt, Ruth; Nordestgaard, Børge G; Jensen, Gorm B

    2004-01-01

    Homozygosity for mutations in ABC transporter A1 (ABCA1) causes Tangier disease, a rare HDL-deficiency syndrome. Whether heterozygosity for genetic variation in ABCA1 also contributes to HDL cholesterol (HDL-C) levels in the general population is presently unclear. We determined whether mutations...... or single-nucleotide polymorphisms (SNPs) in ABCA1 were overrepresented in individuals with the lowest 1% (n=95) or highest 1% (n=95) HDL-C levels in the general population by screening the core promoter and coding region of ABCA1. For all nonsynonymous SNPs identified, we determined the effect of genotype...... on lipid traits in 9,259 individuals from the general population. Heterozygosity for ABCA1 mutations was identified in 10% of individuals with low HDL-C only. Three of 6 nonsynonymous SNPs (V771M, V825I, and R1587K) were associated with increases or decreases in HDL-C in women in the general population...

  12. Whole-genome survey of the putative ATP-binding cassette transporter family genes in Vitis vinifera.

    Science.gov (United States)

    Çakır, Birsen; Kılıçkaya, Ozan

    2013-01-01

    The ATP-binding cassette (ABC) protein superfamily constitutes one of the largest protein families known in plants. In this report, we performed a complete inventory of ABC protein genes in Vitis vinifera, the whole genome of which has been sequenced. By comparison with ABC protein members of Arabidopsis thaliana, we identified 135 putative ABC proteins with 1 or 2 NBDs in V. vinifera. Of these, 120 encode intrinsic membrane proteins, and 15 encode proteins missing TMDs. V. vinifera ABC proteins can be divided into 13 subfamilies with 79 "full-size," 41 "half-size," and 15 "soluble" putative ABC proteins. The main feature of the Vitis ABC superfamily is the presence of 2 large subfamilies, ABCG (pleiotropic drug resistance and white-brown complex homolog) and ABCC (multidrug resistance-associated protein). We identified orthologs of V. vinifera putative ABC transporters in different species. This work represents the first complete inventory of ABC transporters in V. vinifera. The identification of Vitis ABC transporters and their comparative analysis with the Arabidopsis counterparts revealed a strong conservation between the 2 species. This inventory could help elucidate the biological and physiological functions of these transporters in V. vinifera.

  13. Whole-genome survey of the putative ATP-binding cassette transporter family genes in Vitis vinifera.

    Directory of Open Access Journals (Sweden)

    Birsen Çakır

    Full Text Available The ATP-binding cassette (ABC protein superfamily constitutes one of the largest protein families known in plants. In this report, we performed a complete inventory of ABC protein genes in Vitis vinifera, the whole genome of which has been sequenced. By comparison with ABC protein members of Arabidopsis thaliana, we identified 135 putative ABC proteins with 1 or 2 NBDs in V. vinifera. Of these, 120 encode intrinsic membrane proteins, and 15 encode proteins missing TMDs. V. vinifera ABC proteins can be divided into 13 subfamilies with 79 "full-size," 41 "half-size," and 15 "soluble" putative ABC proteins. The main feature of the Vitis ABC superfamily is the presence of 2 large subfamilies, ABCG (pleiotropic drug resistance and white-brown complex homolog and ABCC (multidrug resistance-associated protein. We identified orthologs of V. vinifera putative ABC transporters in different species. This work represents the first complete inventory of ABC transporters in V. vinifera. The identification of Vitis ABC transporters and their comparative analysis with the Arabidopsis counterparts revealed a strong conservation between the 2 species. This inventory could help elucidate the biological and physiological functions of these transporters in V. vinifera.

  14. ABC gene-ranking for prediction of drug-induced cholestasis in rats

    Directory of Open Access Journals (Sweden)

    Yauheniya Cherkas

    2016-01-01

    Full Text Available As legacy toxicogenomics databases have become available, improved data mining approaches are now key to extracting and visualizing subtle relationships between toxicants and gene expression. In the present study, a novel “aggregating bundles of clusters” (ABC procedure was applied to separate cholestatic from non-cholestatic drugs and model toxicants in the Johnson & Johnson (Janssen rat liver toxicogenomics database [3]. Drug-induced cholestasis is an important issue, particularly when a new compound enters the market with this liability, with standard preclinical models often mispredicting this toxicity. Three well-characterized cholestasis-responsive genes (Cyp7a1, Mrp3 and Bsep were chosen from a previous in-house Janssen gene expression signature; these three genes show differing, non-redundant responses across the 90+ paradigm compounds in our database. Using the ABC procedure, extraneous contributions were minimized in comparisons of compound gene responses. All genes were assigned weights proportional to their correlations with Cyp7a1, Mrp3 and Bsep, and a resampling technique was used to derive a stable measure of compound similarity. The compounds that were known to be associated with rat cholestasis generally had small values of this measure relative to each other but also had large values of this measure relative to non-cholestatic compounds. Visualization of the data with the ABC-derived signature showed a very tight, essentially identically behaving cluster of robust human cholestatic drugs and experimental cholestatic toxicants (ethinyl estradiol, LPS, ANIT and methylene dianiline, disulfiram, naltrexone, methapyrilene, phenacetin, alpha-methyl dopa, flutamide, the NSAIDs–—indomethacin, flurbiprofen, diclofenac, flufenamic acid, sulindac, and nimesulide, butylated hydroxytoluene, piperonyl butoxide, and bromobenzene, some slightly less active compounds (3′-acetamidofluorene, amsacrine, hydralazine, tannic acid, some

  15. An Arabidopsis ABC Transporter Mediates Phosphate Deficiency-Induced Remodeling of Root Architecture by Modulating Iron Homeostasis in Roots.

    Science.gov (United States)

    Dong, Jinsong; Piñeros, Miguel A; Li, Xiaoxuan; Yang, Haibing; Liu, Yu; Murphy, Angus S; Kochian, Leon V; Liu, Dong

    2017-02-13

    The remodeling of root architecture is a major developmental response of plants to phosphate (Pi) deficiency and is thought to enhance a plant's ability to forage for the available Pi in topsoil. The underlying mechanism controlling this response, however, is poorly understood. In this study, we identified an Arabidopsis mutant, hps10 (hypersensitive to Pi starvation 10), which is morphologically normal under Pi sufficient condition but shows increased inhibition of primary root growth and enhanced production of lateral roots under Pi deficiency. hps10 is a previously identified allele (als3-3) of the ALUMINUM SENSITIVE3 (ALS3) gene, which is involved in plant tolerance to aluminum toxicity. Our results show that ALS3 and its interacting protein AtSTAR1 form an ABC transporter complex in the tonoplast. This protein complex mediates a highly electrogenic transport in Xenopus oocytes. Under Pi deficiency, als3 accumulates higher levels of Fe(3+) in its roots than the wild type does. In Arabidopsis, LPR1 (LOW PHOSPHATE ROOT1) and LPR2 encode ferroxidases, which when mutated, reduce Fe(3+) accumulation in roots and cause root growth to be insensitive to Pi deficiency. Here, we provide compelling evidence showing that ALS3 cooperates with LPR1/2 to regulate Pi deficiency-induced remodeling of root architecture by modulating Fe homeostasis in roots.

  16. Functional genetic identification of PRP1, an ABC transporter superfamily member conferring pentamidine resistance in Leishmania major.

    Science.gov (United States)

    Coelho, Adriano C; Beverley, Stephen M; Cotrim, Paulo C

    2003-08-31

    Pentamidine (PEN) is a second-line agent in the treatment of leishmaniasis whose mode of action and resistance is not well understood. Here, we used a genetic strategy to search for loci able to mediate PEN resistance (PENr) when overexpressed in Leishmania major. A shuttle cosmid library containing genomic DNA inserts was transfected into wild-type promastigotes and screened for PEN-resistant transfectants. Two different cosmids identifying the same locus were found, which differed from other known Leishmania drug resistance genes. The PENr gene was mapped by deletion and transposon mutagenesis to an open reading frame (ORF) belonging to the P-glycoprotein (PGP)/MRP ATP-binding cassette (ABC) transporter superfamily that we named pentamidine resistance protein 1 (PRP1). The predicted PRP1 protein encodes 1,807 amino acids with the typical dimeric structure involving 10 transmembrane domains and two nucleotide-binding domains (NBDs). PRP1-mediated PENr could be reversed by verapamil and PRP1 overexpressors showed cross-resistance to trivalent antimony but not to pentavalent antimony (glucantime). Although the degree of PENr was modest (1.7- to 3.7-fold), this may be significant in clinical drug resistance given the marginal efficacy of PEN against Leishmania.

  17. A subset of annular lipids is linked to the flippase activity of an ABC transporter.

    Science.gov (United States)

    Bechara, Chérine; Nöll, Anne; Morgner, Nina; Degiacomi, Matteo T; Tampé, Robert; Robinson, Carol V

    2015-03-01

    Lipids are critical components of membranes that could affect the properties of membrane proteins, yet the precise compositions of lipids surrounding membrane-embedded protein complexes is often difficult to discern. Here we report that, for the heterodimeric ABC transporter TmrAB, the extent of delipidation can be controlled by timed exposure to detergent. We subsequently characterize the cohort of endogenous lipids that are extracted in contact with the membrane protein complex, and show that with prolonged delipidation the number of neutral lipids is reduced in favour of their negatively charged counterparts. We show that lipid A is retained by the transporter and that the extent of its binding decreases during the catalytic cycle, implying that lipid A release is linked to adenosine tri-phosphate hydrolysis. Together, these results enable us to propose that a subset of annular lipids is invariant in composition, with negatively charged lipids binding tightly to TmrAB, and imply a role for this exporter in glycolipid translocation.

  18. Involvement of the carboxyl-terminal region of the yeast peroxisomal half ABC transporter Pxa2p in its interaction with Pxa1p and in transporter function.

    Directory of Open Access Journals (Sweden)

    Cheng-Yi Chuang

    Full Text Available BACKGROUND: The peroxisome is a single membrane-bound organelle in eukaryotic cells involved in lipid metabolism, including β-oxidation of fatty acids. The human genetic disorder X-linked adrenoleukodystrophy (X-ALD is caused by mutations in the ABCD1 gene (encoding ALDP, a peroxisomal half ATP-binding cassette [ABC] transporter. This disease is characterized by defective peroxisomal β-oxidation and a large accumulation of very long-chain fatty acids in brain white matter, adrenal cortex, and testis. ALDP forms a homodimer proposed to be the functional transporter, whereas the peroxisomal transporter in yeast is a heterodimer comprising two half ABC transporters, Pxa1p and Pxa2p, both orthologs of human ALDP. While the carboxyl-terminal domain of ALDP is engaged in dimerization, it remains unknown whether the same region is involved in the interaction between Pxa1p and Pxa2p. METHODS/PRINCIPAL FINDINGS: Using a yeast two-hybrid assay, we found that the carboxyl-terminal region (CT of Pxa2p, but not of Pxa1p, is required for their interaction. Further analysis indicated that the central part of the CT (designated CT2 of Pxa2p was indispensable for its interaction with the carboxyl terminally truncated Pxa1_NBD. An interaction between the CT of Pxa2p and Pxa1_NBD was not detected, but could be identified in the presence of Pxa2_NBD-CT1. A single mutation of two conserved residues (aligned with X-ALD-associated mutations at the same positions in ALDP in the CT2 of the Pxa2_NBD-CT protein impaired its interaction with Pxa1_NBD or Pxa1_NBD-CT, resulting in a mutant protein that exhibited a proteinase K digestion profile different from that of the wild-type protein. Functional analysis of these mutant proteins on oleate plates indicated that they were defective in transporter function. CONCLUSIONS/SIGNIFICANCE: The CT of Pxa2p is involved in its interaction with Pxa1p and in transporter function. This concept may be applied to human ALDP studies

  19. The ABCs of eye color in Tribolium castaneum: orthologs of the Drosophila white, scarlet, and brown Genes.

    Science.gov (United States)

    Grubbs, Nathaniel; Haas, Sue; Beeman, Richard W; Lorenzen, Marcé D

    2015-03-01

    In Drosophila melanogaster, each of the three paralogous ABC transporters, White, Scarlet and Brown, is required for normal pigmentation of the compound eye. We have cloned the three orthologous genes from the beetle Tribolium castaneum. Conceptual translations of Tribolium white (Tcw), scarlet (Tcst), and brown (Tcbw) are 51, 48, and 32% identical to their respective Drosophila counterparts. We have identified loss-of-eye-pigment strains that bear mutations in Tcw and Tcst: the Tcw gene in the ivory (i) strain carries a single-base transversion, which leads to an E → D amino-acid substitution in the highly conserved Walker B motif, while the Tcst gene in the pearl (p) strain has a deletion resulting in incorporation of a premature stop codon. In light of these findings, the mutant strains i and p are herein renamed white(ivory) (w(i)) and scarlet(pearl) (st(p)), respectively. In addition, RNA inhibition of Tcw and Tcst recapitulates the mutant phenotypes, confirming the roles of these genes in normal eye pigmentation, while RNA interference of Tcbw provides further evidence that it has no role in eye pigmentation in Tribolium. We also consider the evolutionary implications of our findings.

  20. Molecular mechanics investigation of the transport mechanisms in the CIC-ec1 H+/CI⁻ exchanger and P-glycoprotein/Sav1866 ABC transporter

    OpenAIRE

    Xu, Yanyan

    2014-01-01

    Although channels and transporters were thought to display completely different transport mechanisms, new findings have revealed that the boundaries between them might be more blurred. ABC family, which includes thousands of transporters, holds a channel member, CFTR (cystic fibrosis transmembrane conductance regulator). ClC-ec1, which was considered as a chloride ion channel as other members of the ClC family, was found to function as a Cl-/H+ exchanger. Since the proteins within the family ...

  1. Detoxification of multiple heavy metals by a half-molecule ABC transporter, HMT-1, and coelomocytes of Caenorhabditis elegans.

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    Marc S Schwartz

    Full Text Available BACKGROUND: Developing methods for protecting organisms in metal-polluted environments is contingent upon our understanding of cellular detoxification mechanisms. In this regard, half-molecule ATP-binding cassette (ABC transporters of the HMT-1 subfamily are required for cadmium (Cd detoxification. HMTs have conserved structural architecture that distinguishes them from other ABC transporters and allows the identification of homologs in genomes of different species including humans. We recently discovered that HMT-1 from the simple, unicellular organism, Schizosaccharomyces pombe, SpHMT1, acts independently of phytochelatin synthase (PCS and detoxifies Cd, but not other heavy metals. Whether HMTs from multicellular organisms confer tolerance only to Cd or also to other heavy metals is not known. METHODOLOGY/PRINCIPAL FINDINGS: Using molecular genetics approaches and functional in vivo assays we showed that HMT-1 from a multicellular organism, Caenorhabditis elegans, functions distinctly from its S. pombe counterpart in that in addition to Cd it confers tolerance to arsenic (As and copper (Cu while acting independently of pcs-1. Further investigation of hmt-1 and pcs-1 revealed that these genes are expressed in different cell types, supporting the notion that hmt-1 and pcs-1 operate in distinct detoxification pathways. Interestingly, pcs-1 and hmt-1 are co-expressed in highly endocytic C. elegans cells with unknown function, the coelomocytes. By analyzing heavy metal and oxidative stress sensitivities of the coelomocyte-deficient C. elegans strain we discovered that coelomocytes are essential mainly for detoxification of heavy metals, but not of oxidative stress, a by-product of heavy metal toxicity. CONCLUSIONS/SIGNIFICANCE: We established that HMT-1 from the multicellular organism confers tolerance to multiple heavy metals and is expressed in liver-like cells, the coelomocytes, as well as head neurons and intestinal cells, which are cell types

  2. Impaired mitochondrial energy production and ABC transporter function-A crucial interconnection in dementing proteopathies of the brain.

    Science.gov (United States)

    Pahnke, Jens; Fröhlich, Christina; Krohn, Markus; Schumacher, Toni; Paarmann, Kristin

    2013-10-01

    Ageing is the main risk factor for the development of dementing neurodegenerative diseases (NDs) and it is accompanied by the accumulation of variations in mitochondrial DNA. The resulting tissue-specific alterations in ATP production and availability cause deteriorations of cerebral clearance mechanisms that are important for the removal of toxic peptides and its aggregates. ABC transporters were shown to be the most important exporter superfamily for toxic peptides, e.g. β-amyloid and α-synuclein. Their activity is highly dependent on the availability of ATP and forms a directed energy-exporter network, linking decreased mitochondrial function with highly impaired ABC transporter activity and disease progression. In this paper, we describe a network based on interactions between ageing, energy metabolism, regeneration, accumulation of toxic peptides and the development of proteopathies of the brain with a focus on Alzheimer's disease (AD). Additionally, we provide new experimental evidence for interactions within this network in regenerative processes in AD.

  3. H-loop histidine catalyzes ATP hydrolysis in the E. coli ABC-transporter HlyB.

    Science.gov (United States)

    Zhou, Yan; Ojeda-May, Pedro; Pu, Jingzhi

    2013-10-14

    Adenosine triphosphate (ATP)-binding cassette (ABC) transporters form a family of molecular motor proteins that couple ATP hydrolysis to substrate translocation across cell membranes. Each nucleotide binding domain of ABC-transporters contains a highly conserved H-loop histidine residue, whose precise mechanistic role in motor functions has remained elusive. By using combined quantum mechanical and molecular mechanical (QM/MM) calculations, we showed that the conserved H-loop residue H662 in E. coli HlyB, a bacterial ABC-transporter, can act first as a general acid and then as a general base to facilitate proton transfer in ATP hydrolysis. Without the assistance of H662, direct proton transfer from the lytic water to ATP results in a substantially higher barrier height. Our findings suggest that the essential function of the H-loop residue H662 is to provide a "chemical linchpin" that shuttles protons between reactants through a relay mechanism, thereby catalyzing ATP hydrolysis in HlyB.

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

    OpenAIRE

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

    2006-01-01

    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 ch...

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

    Science.gov (United States)

    Němcová-Fürstová, Vlasta; Kopperová, Dana; Balušíková, Kamila; Ehrlichová, Marie; Brynychová, Veronika; Václavíková, Radka; Daniel, Petr; Souček, Pavel; Kovář, Jan

    2016-11-01

    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 100nM and 300nM 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 sublines 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.

  6. A rice ABC transporter, OsABCC1, reduces arsenic accumulation in the grain

    Science.gov (United States)

    Song, Won-Yong; Yamaki, Tomohiro; Yamaji, Naoki; Ko, Donghwi; Jung, Ki-Hong; Fujii-Kashino, Miho; An, Gynheung; Martinoia, Enrico; Lee, Youngsook; Ma, Jian Feng

    2014-01-01

    Arsenic (As) is a chronic poison that causes severe skin lesions and cancer. Rice (Oryza sativa L.) is a major dietary source of As; therefore, reducing As accumulation in the rice grain and thereby diminishing the amount of As that enters the food chain is of critical importance. Here, we report that a member of the Oryza sativa C-type ATP-binding cassette (ABC) transporter (OsABCC) family, OsABCC1, is involved in the detoxification and reduction of As in rice grains. We found that OsABCC1 was expressed in many organs, including the roots, leaves, nodes, peduncle, and rachis. Expression was not affected when plants were exposed to low levels of As but was up-regulated in response to high levels of As. In both the basal nodes and upper nodes, which are connected to the panicle, OsABCC1 was localized to the phloem region of vascular bundles. Furthermore, OsABCC1 was localized to the tonoplast and conferred phytochelatin-dependent As resistance in yeast. Knockout of OsABCC1 in rice resulted in decreased tolerance to As, but did not affect cadmium toxicity. At the reproductive growth stage, the As content was higher in the nodes and in other tissues of wild-type rice than in those of OsABCC1 knockout mutants, but was significantly lower in the grain. Taken together, our results indicate that OsABCC1 limits As transport to the grains by sequestering As in the vacuoles of the phloem companion cells of the nodes in rice. PMID:25331872

  7. ABC transporter genes and risk of type 2 diabetes

    DEFF Research Database (Denmark)

    Schou, Jesper; Tybjærg-Hansen, Anne; Møller, Holger J;

    2012-01-01

    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 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...

  8. Transcriptional control of hepatocanalicular transporter gene expression

    NARCIS (Netherlands)

    Muller, M

    2000-01-01

    Transport processes for larger organic solutes at the canalicular membrane are mainly driven by members of the superfamily of ATP-binding cassette (ABC) transporters. The funct ions of these transporters range from bile component secretion to xenobiotica and phase II-conjugate export. The transcript

  9. Active transmembrane drug transport in microgravity: a validation study using an ABC transporter model [v1; ref status: indexed, http://f1000r.es/41n

    Directory of Open Access Journals (Sweden)

    Sergi Vaquer

    2014-08-01

    Full Text Available Abstract Microgravity has been shown to influence the expression of ABC (ATP-Binding Cassette transporters in bacteria, fungi and mammals, but also to modify the activity of certain cellular components with structural and functional similarities to ABC transporters. Changes in activity of ABC transporters could lead to important metabolic disorders and undesired pharmacological effects during spaceflights. However, no current means exist to study the functionality of these transporters in microgravity. To this end, a Vesicular Transport Assay® (Solvo Biotechnology, Hungary was adapted to evaluate multi-drug resistance-associated protein 2 (MRP2 trans-membrane estradiol-17-β-glucuronide (E17βG transport activity, when activated by adenosine-tri-phosphate (ATP during parabolic flights. Simple diffusion, ATP-independent transport and benzbromarone inhibition were also evaluated. A high accuracy engineering system was designed to perform, monitor and synchronize all procedures. Samples were analysed using a validated high sensitivity drug detection protocol. Experiments were performed in microgravity during parabolic flights, and compared to 1g on ground results using identical equipment and procedures in all cases. Our results revealed that sufficient equipment accuracy and analytical sensitivity were reached to detect transport activity in both gravitational conditions. Additionally, transport activity levels of on ground samples were within commercial transport standards, proving the validity of the methods and equipment used. MRP2 net transport activity was significantly reduced in microgravity, so was signal detected in simple diffusion samples. Ultra-structural changes induced by gravitational stress upon vesicle membranes or transporters could explain the current results, although alternative explanations are possible. Further research is needed to provide a conclusive answer in this regard. Nevertheless, the present validated technology

  10. IMG-ABC: An Atlas of Biosynthetic Gene Clusters to Fuel the Discovery of Novel Secondary Metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Chen, I-Min; Chu, Ken; Ratner, Anna; Palaniappan, Krishna; Huang, Jinghua; Reddy, T. B.K.; Cimermancic, Peter; Fischbach, Michael; Ivanova, Natalia; Markowitz, Victor; Kyrpides, Nikos; Pati, Amrita

    2014-10-28

    In the discovery of secondary metabolites (SMs), large-scale analysis of sequence data is a promising exploration path that remains largely underutilized due to the lack of relevant computational resources. We present IMG-ABC (https://img.jgi.doe.gov/abc/) -- An Atlas of Biosynthetic gene Clusters within the Integrated Microbial Genomes (IMG) system1. IMG-ABC is a rich repository of both validated and predicted biosynthetic clusters (BCs) in cultured isolates, single-cells and metagenomes linked with the SM chemicals they produce and enhanced with focused analysis tools within IMG. The underlying scalable framework enables traversal of phylogenetic dark matter and chemical structure space -- serving as a doorway to a new era in the discovery of novel molecules.

  11. Cloning and Expression Analysis of a MDR-type ABC Transporter Abundant in Rubber Tree Latex%橡胶树一个胶乳高表达MDR型ABC转运蛋白的克隆与表达研究

    Institute of Scientific and Technical Information of China (English)

    聂智毅; 李波; 白瑞璞; 黎瑜

    2011-01-01

    ABC (ATP-Binding Cassette) transporters constitute the largest protein family with the most variety of functions.They are involved in the excretion, accumulation and the transmembrane transport of plant secondary metabolites.Through screening an ethylene-induced latex SSH cDNA library combined with RACE,one ABC transporter gene EST and its full-length cDNA were obtained, which was 3753 bp with an ORF that encoded a polypeptide of 1251 amino acids.The results showed that the ABC transporter gene had multiple copies in rubber tree genome and was primarily expressed in latex.Under ethylene or jasmonic acid induction,its expression was up-regulated.Base on above analysis, we speculated that the ABC transporter was closely correlated to the transport of rubber biosynthesis metabolites.%ABC转运蛋白(ATP-Binding Cassette)是目前已知最大、功能最广泛的蛋白家族之一,与植物次生代谢物的排泌、积累及跨膜运转密切相关.本研究筛选已构建的乙烯刺激橡胶树胶乳消减文库,克隆了1个ABC转运蛋白基因EST,通过RACE技术获得其全长cDNA序列,该基因开放阅读框(ORF)共3753 bp,编码1251个氨基酸残基.研究表明其在橡胶树基因组中存在多个拷贝,主要在胶乳中表达,且在乙烯或茉莉酸刺激(刺激产胶)条件下上调表达.推测其可能与橡胶生物合成过程中的物质转运密切相关.

  12. Effects of in vitro exposure to ivermectin and levamisole on the expression patterns of ABC transporters in Haemonchus contortus larvae.

    Science.gov (United States)

    Raza, Ali; Kopp, Steven R; Bagnall, Neil H; Jabbar, Abdul; Kotze, Andrew C

    2016-08-01

    This study investigated the interaction of ATP binding cassette (ABC) transport proteins with ivermectin (IVM) and levamisole (LEV) in larvae of susceptible and resistant isolates of Haemonchus contortus in vitro by measuring transcription patterns following exposure to these anthelmintics. Furthermore, we studied the consequences of drug exposure by measuring the sensitivity of L3 to subsequent exposure to higher drug concentrations using larval migration assays. The most highly transcribed transporter genes in both susceptible and resistant L3 were pgp-9.3, abcf-1, mrp-5, abcf-2, pgp-3, and pgp-10. The resistant isolate showed significantly higher transcription of pgp-1, pgp-9.1 and pgp-9.2 compared to the susceptible isolate. Five P-gp genes and the haf-6 gene showed significantly higher transcription (up to 12.6-fold) after 3 h exposure to IVM in the resistant isolate. Similarly, five P-gp genes, haf-6 and abcf-1 were transcribed at significantly higher levels (up to 10.3-fold) following 3 h exposure to LEV in this isolate. On the other hand, there were no significant changes in transcriptional patterns of all transporter genes in the susceptible isolate following 3 and 6 h exposure to IVM or LEV. In contrast to these isolate-specific transcription changes, both isolates showed an increase in R-123 efflux following exposure to the drugs, suggesting that the drugs stimulated activity of existing transporter proteins in both isolates. Exposure of resistant larvae to IVM or LEV resulted, in some instances, in an increase in the proportion of the population able to migrate at the highest IVM concentrations in subsequent migration assays. The significant increase in transcription of some ABC transporter genes following 3 h exposure to both IVM and LEV in the resistant isolate only, suggests that an ability to rapidly upregulate protective pathways in response to drugs may be a component of the resistance displayed by this isolate.

  13. Effects of in vitro exposure to ivermectin and levamisole on the expression patterns of ABC transporters in Haemonchus contortus larvae

    Directory of Open Access Journals (Sweden)

    Ali Raza

    2016-08-01

    Full Text Available This study investigated the interaction of ATP binding cassette (ABC transport proteins with ivermectin (IVM and levamisole (LEV in larvae of susceptible and resistant isolates of Haemonchus contortus in vitro by measuring transcription patterns following exposure to these anthelmintics. Furthermore, we studied the consequences of drug exposure by measuring the sensitivity of L3 to subsequent exposure to higher drug concentrations using larval migration assays. The most highly transcribed transporter genes in both susceptible and resistant L3 were pgp-9.3, abcf-1, mrp-5, abcf-2, pgp-3, and pgp-10. The resistant isolate showed significantly higher transcription of pgp-1, pgp-9.1 and pgp-9.2 compared to the susceptible isolate. Five P-gp genes and the haf-6 gene showed significantly higher transcription (up to 12.6-fold after 3 h exposure to IVM in the resistant isolate. Similarly, five P-gp genes, haf-6 and abcf-1 were transcribed at significantly higher levels (up to 10.3-fold following 3 h exposure to LEV in this isolate. On the other hand, there were no significant changes in transcriptional patterns of all transporter genes in the susceptible isolate following 3 and 6 h exposure to IVM or LEV. In contrast to these isolate-specific transcription changes, both isolates showed an increase in R-123 efflux following exposure to the drugs, suggesting that the drugs stimulated activity of existing transporter proteins in both isolates. Exposure of resistant larvae to IVM or LEV resulted, in some instances, in an increase in the proportion of the population able to migrate at the highest IVM concentrations in subsequent migration assays. The significant increase in transcription of some ABC transporter genes following 3 h exposure to both IVM and LEV in the resistant isolate only, suggests that an ability to rapidly upregulate protective pathways in response to drugs may be a component of the resistance displayed by this isolate.

  14. Effect of the deletion of qmoABC and the promoter distal gene encoding a hypothetical protein on sulfate-reduction in Desulfovibrio vulgaris Hildenborough

    Energy Technology Data Exchange (ETDEWEB)

    Zane, Grant M.; Yen, Huei-chi Bill; Wall, Judy D.

    2010-03-18

    The pathway of electrons required for the reduction of sulfate in sulfate-reducing bacteria (SRB) is not yet fully characterized. In order to determine the role of a transmembrane protein complex suggested to be involved in this process, a deletion of Desulfovibrio vulgaris Hildenborough was created by marker exchange mutagenesis that eliminated four genes putatively encoding the QmoABC complex and a hypothetical protein (DVU0851). The Qmo complex (quinone-interacting membrane-bound oxidoreductase) is proposed to be responsible for transporting electrons to the dissimilatory adenosine-5?phosphosulfate (APS) reductase in SRB. In support of the predicted role of this complex, the deletion mutant was unable to grow using sulfate as its sole electron acceptor with a range of electron donors. To explore a possible role for the hypothetical protein in sulfate reduction, a second mutant was constructed that had lost only the gene that codes for DVU0851. The second constructed mutant grew with sulfate as the sole electron acceptor; however, there was a lag that was not present with the wild-type or complemented strain. Neither deletion strain was significantly impaired for growth with sulfite or thiosulfate as terminal electron acceptor. Complementation of the D(qmoABC-DVU0851) mutant with all four genes or only the qmoABC genes restored its ability to grow by sulfate respiration. These results confirmed the prediction that the Qmo complex is in the electron pathway for sulfate-reduction and revealed that no other transmembrane complex could compensate when Qmo was lacking.

  15. ABC细胞膜转运蛋白及其介导的细胞多药耐药研究进展%Advancement of Multidrug Resistance Induced by ABC Transporters

    Institute of Scientific and Technical Information of China (English)

    张久聪; 王彪猛; 常宗宏; 张方信

    2014-01-01

    ABC细胞膜转运蛋白是一个能转运多种底物的蛋白质家族,其在宿主对异物的防御机制和肿瘤细胞对抗癌药物的耐药性中发挥重要作用。ABC转运蛋白能将已进人细胞的外源性物质从胞内泵出胞外,是造成肿瘤细胞多药耐药的主要原因,其基因表达水平与细胞内药物浓度和耐药程度密切相关。近年来,肿瘤细胞多药耐药性研究炙手可热。我们简要综述ABC细胞膜转运蛋白的特点、分布、表达及其介导的细胞多药耐药方面的研究进展。%ABC transporters are a class of membrane transport proteins which can transport a variety of sub⁃strates. ABC transporters play an pivital role in the host defense mechanism and tumor cell resistance to antican⁃cer drugs. Since ABC transporters can pump intra-cellular exogenous substances to the extracellular enviroment, it is considered the main reason responsible for the multidrug resistance of tumor cells. Which is more, the intracel⁃lular drug concentration and the drug resistance degree were closely related to the gene expression level of ABC transporters. In recent years, the study of multi-drug resistant tumor cells became a hotspot, a lot of experiments research has been accomplished by domestic and foreign scholars on the multidrug resistance of tumor cells in⁃duced by ABC transporters. This paper briefly reviewed the characteristics, distribution, expression, and some prog⁃ress of ABC transporters with regard to tumor multidrug resistance.

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

    Directory of Open Access Journals (Sweden)

    Teixeira Miguel C

    2012-07-01

    Full Text Available Abstract 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

  17. Role of the ABC transporter PRP1 (ABCC7) in pentamidine resistance in Leishmania amastigotes.

    Science.gov (United States)

    Coelho, Adriano C; Messier, Nadine; Ouellette, Marc; Cotrim, Paulo C

    2007-08-01

    Pentamidine is a second-line agent in the treatment of leishmaniasis whose mode of action and resistance mechanism are not well understood. In this work, we show that the intracellular ABC protein PRP1 (pentamidine resistance protein 1) (ABCC7) can confer resistance to pentamidine in Leishmania sp. parasites in the intracellular stage.

  18. 1.55 A structure of the ectoine binding protein TeaA of the osmoregulated TRAP-transporter TeaABC from Halomonas elongata.

    Science.gov (United States)

    Kuhlmann, Sonja I; Terwisscha van Scheltinga, Anke C; Bienert, Ralf; Kunte, Hans-Jörg; Ziegler, Christine

    2008-09-09

    TeaABC from the moderate halophilic bacterium Halomonas elongata belongs to the tripartite ATP-independent periplasmic transporters (TRAP-T), a family of secondary transporters functioning in conjunction with periplasmic substrate binding proteins. TeaABC facilitates the uptake of the compatible solutes ectoine and hydroxyectoine that are accumulated in the cytoplasm under hyperosmotic stress to protect the cell from dehydration. TeaABC is the only known TRAP-T activated by osmotic stress. Currently, our knowledge on the osmoregulated compatible solute transporter is limited to ABC transporters or conventional secondary transporters. Therefore, this study presents the first detailed analysis of the molecular mechanisms underlying substrate recognition of the substrate binding protein of an osmoregulated TRAP-T. In the present study we were able to demonstrate by isothermal titration calorimetry measurements that TeaA is a high-affinity ectoine binding protein ( K d = 0.19 microM) that also has a significant but somewhat lower affinity to hydroxyectoine ( K d = 3.8 microM). Furthermore, we present the structure of TeaA in complex with ectoine at a resolution of 1.55 A and hydroxyectoine at a resolution of 1.80 A. Analysis of the TeaA binding pocket and comparison of its structure to other compatible solute binding proteins from ABC transporters reveal common principles in compatible solute binding but also significant differences like the solvent-mediated specific binding of ectoine to TeaA.

  19. ABC转运蛋白与巴西橡胶树产胶代谢%ABC Transporters and the Latex Regeneration Metabolism of Hevea brasiliensis

    Institute of Scientific and Technical Information of China (English)

    聂智毅; 黎瑜; 曾日中

    2013-01-01

    ABC转运蛋白(ATP Binding Cassette transporter)是目前已知最大、功能最广泛的蛋白家族之一。大多数ABC转运蛋白都能利用水解ATP释放的能量直接转运底物。许多研究结果显示,植物ABC转运蛋白在各种代谢产物的跨膜转运中起着重要作用。橡胶的产胶代谢是一种典型的植物类异戊二烯次生代谢,是影响橡胶产量的首要因素。相关实验结果显示, ABC转运蛋白可能参与橡胶树产胶代谢。本文介绍了模式植物拟南芥中的ABC转运蛋白研究进展,并对ABC转运蛋白与橡胶树产胶代谢的关系进行讨论。%ATP Binding Cassette transporters (ABC transporters) constitute the largest protein family with the most variety of functions. Most ABC transporters can utilize the energy of ATP hydrolysis to transport substances, and many researches reveal that ABC transporters play important roles in translocation of plant metabolites across membranes. Latex regeneration metabolism of Hevea brasiliensis is a typical of plant isoprenoid secondary metabolism and is the primary factor affecting rubber production. Researches reveal that ABC-transporters may be involved in the latex regeneration metabolism of Hevea brasiliensis. Base on the new advances in ABC-transporters in A rabidopsis thaliana, the relation between ABC-transporters and latex regeneration of Hevea brasiliensis was discussed in the review.

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

    DEFF Research Database (Denmark)

    Andersen, Vibeke; Svenningsen, Katrine; Almind Knudsen, Lina;

    2015-01-01

    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...... 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...

  1. Hamiltonian ABC

    NARCIS (Netherlands)

    Meeds, E.; Leenders, R.; Welling, M.; Meila, M.; Heskes, T.

    2015-01-01

    Approximate Bayesian computation (ABC) is a powerful and elegant framework for performing inference in simulation-based models. However, due to the difficulty in scaling likelihood estimates, ABC remains useful for relatively lowdimensional problems. We introduce Hamiltonian ABC (HABC), a set of lik

  2. The abcEDCBA-Encoded ABC Transporter and the virB Operon-Encoded Type IV Secretion System of Brucella ovis Are Critical for Intracellular Trafficking and Survival in Ovine Monocyte-Derived Macrophages.

    Directory of Open Access Journals (Sweden)

    Auricelio A Macedo

    Full Text Available Brucella ovis infection is associated with epididymitis, orchitis and infertility in rams. Most of the information available on B. ovis and host cell interaction has been generated using murine macrophages or epithelial cell lines, but the interaction between B. ovis and primary ovine macrophages has not been studied. The aim of this study was to evaluate the role of the B. ovis abcEDCBA-encoded ABC transporter and the virB operon-encoded Type IV Secretion System (T4SS during intracellular survival of B. ovis in ovine peripheral blood monocyte-derived macrophages. ΔabcBA and ΔvirB2 mutant strains were unable to survive in the intracellular environment when compared to the WT B. ovis at 48 hours post infection (hpi. In addition, these mutant strains cannot exclude the lysosomal marker LAMP1 from its vacuolar membrane, and their vacuoles do not acquire the endoplasmic reticulum marker calreticulin, which takes place in the WT B. ovis containing vacuole. Higher levels of nitric oxide production were observed in macrophages infected with WT B. ovis at 48 hpi when compared to macrophages infected with the ΔabcBA or ΔvirB2 mutant strains. Conversely, higher levels of reactive oxygen species were detected in macrophages infected with the ΔabcBA or ΔvirB2 mutant strains at 48 hpi when compared to macrophages infected with the WT strain. Our results demonstrate that B. ovis is able to persist and multiply in ovine macrophages, while ΔabcBA and ΔvirB2 mutations prevent intracellular multiplication, favor phagolysosome fusion, and impair maturation of the B. ovis vacuole towards an endoplasmic reticulum-derived compartment.

  3. The ABC transporter AtrB from Aspergillus nidulans is involved in resistance to all major classes of fungicides and natural toxic compounds

    NARCIS (Netherlands)

    Andrade, A.C.; Del Sorbo, G.; Nistelrooy, van J.G.M.; Waard, de M.A.

    2000-01-01

    This paper reports the functional characterization of AtrBp, an ABC transporter from Aspergillus nidulans. AtrBp is a multidrug transporter and has affinity to substrates belonging to all major classes of agricultural fungicides and some natural toxic compounds. The substrate profile of AtrBp was de

  4. Alkylrhodamines enhance the toxicity of clotrimazole and benzalkonium chloride by interfering with yeast pleiotropic ABC-transporters.

    Science.gov (United States)

    Knorre, Dmitry A; Besedina, Elizaveta; Karavaeva, Iuliia E; Smirnova, Ekaterina A; Markova, Olga V; Severin, Fedor F

    2016-06-01

    ABC-transporters with broad substrate specificity are responsible for pathogenic yeast resistance to antifungal compounds. Here we asked whether highly hydrophobic chemicals with delocalized positive charge can be used to overcome the resistance. Such molecules efficiently penetrate the plasma membrane and accumulate inside the cells. We reasoned that these properties can convert an active efflux of the compounds into a futile cycle thus interfering with the extrusion of the antibiotics. To test this, we studied the effects of several alkylated rhodamines on the drug resistance of yeast Saccharomyces cerevisiae We found that octylrhodamine synergetically increases toxicity of Pdr5p substrate-clotrimazole, while the others were less effective. Next, we compared the contributions of three major pleiotropic ABC-transporters (Pdr5p, Yor1p, Snq2p) on the accumulation of the alkylated rhodamines. While all of the tested compounds were extruded by Pdr5p, Yor1p and Snq2p showed narrower substrate specificity. Interestingly, among the tested alkylated rhodamines, inactivation of Pdr5p had the strongest effect on the accumulation of octylrhodamine inside the cells, which is consistent with the fact that clotrimazole is a substrate of Pdr5p. As alkylated rhodamines were shown to be non-toxic on mice, our study makes them potential components of pharmacological antifungal compositions.

  5. The ABC transporter BcatrB from Botrytis cinerea exports camalexin and is a virulence factor on Arabidopsis thaliana.

    Science.gov (United States)

    Stefanato, Francesca L; Abou-Mansour, Eliane; Buchala, Antony; Kretschmer, Matthias; Mosbach, Andreas; Hahn, Matthias; Bochet, Christian G; Métraux, Jean-Pierre; Schoonbeek, Henk-jan

    2009-05-01

    Arabidopsis thaliana is known to produce the phytoalexin camalexin in response to abiotic and biotic stress. Here we studied the mechanisms of tolerance to camalexin in the fungus Botrytis cinerea, a necrotrophic pathogen of A. thaliana. Exposure of B. cinerea to camalexin induces expression of BcatrB, an ABC transporter that functions in the efflux of fungitoxic compounds. B. cinerea inoculated on wild-type A. thaliana plants yields smaller lesions than on camalexin-deficient A. thaliana mutants. A B. cinerea strain lacking functional BcatrB is more sensitive to camalexin in vitro and less virulent on wild-type plants, but is still fully virulent on camalexin-deficient mutants. Pre-treatment of A. thaliana with UV-C leads to increased camalexin accumulation and substantial resistance to B. cinerea. UV-C-induced resistance was not seen in the camalexin-deficient mutants cyp79B2/B3, cyp71A13, pad3 or pad2, and was strongly reduced in ups1. Here we demonstrate that an ABC transporter is a virulence factor that increases tolerance of the pathogen towards a phytoalexin, and the complete restoration of virulence on host plants lacking this phytoalexin.

  6. 水稻ABC1基因家族的鉴定及在非生物胁迫下的表达分析%Systematic Identification of Rice ABC1 Genes and Their Expression Analysis under Abiotic Stresses

    Institute of Scientific and Technical Information of China (English)

    高清松; 张丹; 徐亮; 徐辰武

    2011-01-01

    ABC1(Activity of bc1 complex)家族属于蛋白质激酶家族,其成员普遍存在于原核和真核生物中.已有研究表明,几个植物ABC1基因参与非生物胁迫应答.为了解ABC1基因在水稻中的结构和功能,采用生物信息学方法分别在水稻和拟南芥上鉴定出15个和17个ABC1基因,并进行了系统发育和表达分析.结果表明,该家族在单、双子叶植物分离之前就已经发生了分化,其基本特征已经形成;单、双子叶植物分离之后,该家族在水稻和拟南芥中均以物种特异的方式进行了扩增.内含子/外显子结构分析显示多数直系同源基因之间外显子大小接近,而内含子差别较大,水稻含有更多大的内含子;内含子获得是近期伴随水稻ABC1家族进化的重要事件.多序列比对显示,ABC1结构域具有1个保守的氨基酸片段和4个保守的氨基酸残基.在线亚细胞定位预测9个水稻ABC1蛋白定位在叶绿体上.实时定量RT-PCR分析表明,水稻ABC1基因主要在叶片中表达,并且受多种非生物胁迫因素包括H2O2、脱落酸、低温、干旱、黑暗和高盐的调控.说明水稻ABC1家族不仅在逆境胁迫应答中发挥重要作用,可能还与水稻特定的生理过程有关.%ABC1 (Activity of bcl complex) family belongs to protein kinase families, whose members widely exist in prokaryotes and eukaryotes. It has been reported that several plant ABC1 genes participate in abiotic stress response. To understand the structure and function of ABC1 genes in rice, the systematic characterization of rice and Arabidopsis ABC1 genes and the expression analysis of rice ABC1 genes were performed. A total of 15 and 17 members of rice and Arabidopsis ABC1 families were identified by the bioinformatics method. The phylogenetic analysis of these proteins suggested that divergence of this family had occurred and the main characteristics had established before the dicot-monocot split; species-specific expansion

  7. A new highly conserved antibiotic sensing/resistance pathway in firmicutes involves an ABC transporter interplaying with a signal transduction system.

    Directory of Open Access Journals (Sweden)

    Stéphanie Coumes-Florens

    Full Text Available Signal transduction systems and ABC transporters often contribute jointly to adaptive bacterial responses to environmental changes. In Bacillus subtilis, three such pairs are involved in responses to antibiotics: BceRSAB, YvcPQRS and YxdJKLM. They are characterized by a histidine kinase belonging to the intramembrane sensing kinase family and by a translocator possessing an unusually large extracytoplasmic loop. It was established here using a phylogenomic approach that systems of this kind are specific but widespread in Firmicutes, where they originated. The present phylogenetic analyses brought to light a highly dynamic evolutionary history involving numerous horizontal gene transfers, duplications and lost events, leading to a great variety of Bce-like repertories in members of this bacterial phylum. Based on these phylogenetic analyses, it was proposed to subdivide the Bce-like modules into six well-defined subfamilies. Functional studies were performed on members of subfamily IV comprising BceRSAB from B. subtilis, the expression of which was found to require the signal transduction system as well as the ABC transporter itself. The present results suggest, for the members of this subfamily, the occurrence of interactions between one component of each partner, the kinase and the corresponding translocator. At functional and/or structural levels, bacitracin dependent expression of bceAB and bacitracin resistance processes require the presence of the BceB translocator loop. Some other members of subfamily IV were also found to participate in bacitracin resistance processes. Taken together our study suggests that this regulatory mechanism might constitute an important common antibiotic resistance mechanism in Firmicutes. [Supplemental material is available online at http://www.genome.org.].

  8. Inhibition of the Human ABC Efflux Transporters P-gp and BCRP by the BDE-47 Hydroxylated Metabolite 6-OH-BDE-47: Considerations for Human Exposure.

    Science.gov (United States)

    Marchitti, Satori A; Mazur, Christopher S; Dillingham, Caleb M; Rawat, Swati; Sharma, Anshika; Zastre, Jason; Kenneke, John F

    2017-01-01

    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 [((3)H)-paclitaxel and ((3)H)-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. These findings suggest that some effects previously attributed to BDE-47 in biological systems may actually be due to 6-OH-BDE-47. Considerations for human exposure are discussed.

  9. Secondary metabolites inhibiting ABC transporters and reversing resistance of cancer cells and fungi to cytotoxic and antimicrobial agents

    Directory of Open Access Journals (Sweden)

    Michael eWink

    2012-04-01

    Full Text Available 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 ABC transporters, such as P-gp, which pump out lipophilic compounds that have entered a cell, 2. Activation of cytochrome p450 oxidases which can oxidise lipophilic agents to make them more hydrophilic and accessible for conjugation reaction with glucuronic acid, sulphate or amino acids, and 3. Activation of glutathione transferase, which can conjugate xenobiotics. This review summarises the evidence that secondary metabolites 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, MRP1 and BCRP 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 MDR, at least partially, of adapted and resistant cells. If these secondary metabolites are applied in combination with a cytotoxic or antimicrobial agent, they may reverse resistance in a synergistic fashion.

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

    Energy Technology Data Exchange (ETDEWEB)

    Fuchs, Dominik [Research Group Molecular Neuro-Oncology, German Cancer Research Center, Im Neuenheimer Feld 280, D-69120 Heidelberg (Germany); Institute of Immunology, University of Heidelberg, Im Neuenheimer Feld 305, D-69120 Heidelberg (Germany); Daniel, Volker; Sadeghi, Mahmoud; Opelz, Gerhard [Institute of Immunology, University of Heidelberg, Im Neuenheimer Feld 305, D-69120 Heidelberg (Germany); Naujokat, Cord, E-mail: cord.naujokat@med.uni-heidelberg.de [Institute of Immunology, University of Heidelberg, Im Neuenheimer Feld 305, D-69120 Heidelberg (Germany)

    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 of 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.

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

    DEFF Research Database (Denmark)

    Andersen, Vibeke; Svenningsen, Katrine; Knudsen, Lina Almind

    2015-01-01

    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 ABCB1 expression identifies a subpopulation of pro-inflammatory Th17 cells which were resistant to treatment...

  12. The ABC transporter AtABCB14 is a malate importer and modulates stomatal response to CO2.

    Science.gov (United States)

    Lee, Miyoung; Choi, Yongwook; Burla, Bo; Kim, Yu-Young; Jeon, Byeongwook; Maeshima, Masayoshi; Yoo, Joo-Yeon; Martinoia, Enrico; Lee, Youngsook

    2008-10-01

    Carbon dioxide uptake and water vapour release in plants occur through stomata, which are formed by guard cells. These cells respond to light intensity, CO2 and water availability, and plant hormones. The predicted increase in the atmospheric concentration of CO2 is expected to have a profound effect on our ecosystem. However, many aspects of CO2-dependent stomatal movements are still not understood. Here we show that the ABC transporter AtABCB14 modulates stomatal closure on transition to elevated CO2. Stomatal closure induced by high CO2 levels was accelerated in plants lacking AtABCB14. Apoplastic malate has been suggested to be one of the factors mediating the stomatal response to CO2 (Refs 4,5) and indeed, exogenously applied malate induced a similar AtABCB14-dependent response as high CO2 levels. In isolated epidermal strips that contained only guard cells, malate-dependent stomatal closure was faster in plants lacking the AtABCB14 and slower in AtABCB14-overexpressing plants, than in wild-type plants, indicating that AtABCB14 catalyses the transport of malate from the apoplast into guard cells. Indeed, when AtABCB14 was heterologously expressed in Escherichia coli and HeLa cells, increases in malate transport activity were observed. We therefore suggest that AtABCB14 modulates stomatal movement by transporting malate from the apoplast into guard cells, thereby increasing their osmotic pressure.

  13. TrmB, a sugar-specific transcriptional regulator of the trehalose/maltose ABC transporter from the hyperthermophilic archaeon Thermococcus litoralis.

    Science.gov (United States)

    Lee, Sung-Jae; Engelmann, Afra; Horlacher, Reinhold; Qu, Qiuhao; Vierke, Gudrun; Hebbeln, Carina; Thomm, Michael; Boos, Winfried

    2003-01-10

    We report the characterization of TrmB, a protein of 38,800 apparent molecular weight, that is involved in the maltose-specific regulation of a gene cluster in Thermococcus litoralis, malE malF malG orf trmB malK, encoding a binding protein-dependent ABC transporter for trehalose and maltose. TrmB binds maltose and trehalose half-maximally at 20 microm and 0.5 mm sugar concentration, respectively. Binding of maltose but not of trehalose showed indications of sigmoidality and quenched the intrinsic tryptophan fluorescence by 15%, indicating a conformational change on maltose binding. TrmB causes a shift in electrophoretic mobility of DNA fragments harboring the promoter and upstream regulatory motif identified by footprinting. Band shifting by TrmB can be prevented by maltose. In vitro transcription assays with purified components from Pyrococcus furiosus have been established to show pmalE promoter-dependent transcription at 80 degrees C. TrmB specifically inhibits transcription, and this inhibition is counteracted by maltose and trehalose. These data characterize TrmB as a maltose-specific repressor for the trehalose/maltose transport operon of Thermococcus litoralis.

  14. The Half-Size ABC Transporter FOLDED PETALS 2/ABCG13 Is Involved in Petal Elongation through Narrow Spaces in Arabidopsis thaliana Floral Buds

    Directory of Open Access Journals (Sweden)

    Seiji Takeda

    2014-08-01

    Full Text Available Flowers are vital for attracting pollinators to plants and in horticulture for humans. Petal morphogenesis is a central process of floral development. Petal development can be divided into three main processes: the establishment of organ identity in a concentric pattern, primordia initiation at fixed positions within a whorl, and morphogenesis, which includes petal elongation through the narrow spaces within the bud. Here, we show that the FOLDED PETALS 2 (FOP2 gene, encoding a member of the half-size ATP binding cassette (ABC transporter family ABCG13, is involved in straight elongation of petals in Arabidopsis thaliana. In fop2 mutants, flowers open with folded petals, instead of straight-elongated ones found in the wild type. The epicuticular nanoridge structures are absent in many abaxial epidermal cells of fop2 petals, and surgical or genetic generation of space in young fop2 buds restores the straight elongation of petals, suggesting that the physical contact of sepals and petals causes the petal folding. Similar petal folding has been reported in the fop1 mutant, and the petals of fop2 fop1 double mutants resemble those of both the fop1 and fop2 single mutants, although the epidermal structure and permeability of the petal surface is more affected in fop2. Our results suggest that synthesis and transport of cutin or wax in growing petals play an important role for their smooth elongation through the narrow spaces of floral buds.

  15. Purification, crystallization and preliminary X-ray diffraction analysis of the putative ABC transporter ATP-binding protein from Thermotoga maritima

    Science.gov (United States)

    Ethayathulla, Abdul S.; Bessho, Yoshitaka; Shinkai, Akeo; Padmanabhan, Balasundaram; Singh, Tej P.; Kaur, Punit; Yokoyama, Shigeyuki

    2008-01-01

    Adenosine triphosphate (ATP) binding cassette transporters (ABC transporters) are ATP hydrolysis-dependent transmembrane transporters. Here, the overproduction, purification and crystallization of the putative ABC transporter ATP-binding protein TM0222 from Thermotoga maritima are reported. The protein was crystallized in the hexagonal space group P6422, with unit-cell parameters a = b = 148.49, c = 106.96 Å, γ = 120.0°. Assuming the presence of two molecules in the asymmetric unit, the calculated V M is 2.84 Å3 Da−1, which corresponds to a solvent content of 56.6%. A three-wavelength MAD data set was collected to 2.3 Å resolution from SeMet-substituted TM0222 crystals. Data sets were collected on the BL38B1 beamline at SPring-8, Japan. PMID:18540059

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

    NARCIS (Netherlands)

    Bhattacharjee, S.; Opstal, van E.J.; Alink, G.M.; Marcelis, A.T.M.; Zuilhof, H.; Rietjens, I.M.C.M.

    2013-01-01

    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/s

  17. YehZYXW of Escherichia coli Is a Low-Affinity, Non-Osmoregulatory Betaine-Specific ABC Transporter.

    Science.gov (United States)

    Lang, Shenhui; Cressatti, Marisa; Mendoza, Kris E; Coumoundouros, Chelsea N; Plater, Samantha M; Culham, Doreen E; Kimber, Matthew S; Wood, Janet M

    2015-09-22

    Transporter-mediated osmolyte accumulation stimulates the growth of Escherichia coli in high-osmolality environments. YehZYXW was predicted to be an osmoregulatory transporter because (1) osmotic and stationary phase induction of yehZYXW is mediated by RpoS, (2) the Yeh proteins are homologous to the components of known osmoregulatory ABC transporters (e.g., ProU of E. coli), and (3) YehZ models based on the structures of periplasmic betaine-binding proteins suggested that YehZ retains key betaine-binding residues. The betaines choline-O-sulfate, glycine betaine, and dimethylsulfoniopropionate bound YehZ and ProX with millimolar and micromolar affinities, respectively, as determined by equilibrium dialysis and isothermal titration calorimetry. The crystal structure of the YehZ apoprotein, determined at 1.5 Å resolution (PDB ID: 4WEP ), confirmed its similarity to other betaine-binding proteins. Small and nonpolar residues in the hinge region of YehZ (e.g., Gly223) pack more closely than the corresponding residues in ProX, stabilizing the apoprotein. Betaines bound YehZ-Gly223Ser an order of magnitude more tightly than YehZ, suggesting that weak substrate binding in YehZ is at least partially due to apo state stabilization. Neither ProX nor YehZ bound proline. Assays based on osmoprotection or proline auxotrophy failed to detect YehZYXW-mediated uptake of proline, betaines, or other osmolytes. However, transport assays revealed low-affinity glycine betaine uptake, mediated by YehZYXW, that was inhibited at high salinity. Thus, YehZYXW is a betaine transporter that shares substrate specificity, but not an osmoregulatory function, with homologues like E. coli ProU. Other work suggests that yehZYXW may be an antivirulence locus whose expression promotes persistent, asymptomatic bacterial infection.

  18. Ligand binding and crystal structures of the substrate-binding domain of the ABC transporter OpuA.

    Directory of Open Access Journals (Sweden)

    Justina C Wolters

    Full Text Available BACKGROUND: The ABC transporter OpuA from Lactococcus lactis transports glycine betaine upon activation by threshold values of ionic strength. In this study, the ligand binding characteristics of purified OpuA in a detergent-solubilized state and of its substrate-binding domain produced as soluble protein (OpuAC was characterized. PRINCIPAL FINDINGS: The binding of glycine betaine to purified OpuA and OpuAC (K(D = 4-6 microM did not show any salt dependence or cooperative effects, in contrast to the transport activity. OpuAC is highly specific for glycine betaine and the related proline betaine. Other compatible solutes like proline and carnitine bound with affinities that were 3 to 4 orders of magnitude lower. The low affinity substrates were not noticeably transported by membrane-reconstituted OpuA. OpuAC was crystallized in an open (1.9 A and closed-liganded (2.3 A conformation. The binding pocket is formed by three tryptophans (Trp-prism coordinating the quaternary ammonium group of glycine betaine in the closed-liganded structure. Even though the binding site of OpuAC is identical to that of its B. subtilis homolog, the affinity for glycine betaine is 4-fold higher. CONCLUSIONS: Ionic strength did not affect substrate binding to OpuA, indicating that regulation of transport is not at the level of substrate binding, but rather at the level of translocation. The overlap between the crystal structures of OpuAC from L.lactis and B.subtilis, comprising the classical Trp-prism, show that the differences observed in the binding affinities originate from outside of the ligand binding site.

  19. Distribution and physiology of ABC-Type transporters contributing to multidrug resistance in bacteria

    NARCIS (Netherlands)

    Lubelski, Jacek; Konings, Wil N.; Driessen, Arnold J. M.

    2007-01-01

    Membrane proteins responsible for the active efflux of structurally and functionally unrelated drugs were first characterized in higher eukalyotes. To date, a vast number of transporters contributing to multidrug resistance (MDR transporters) have been reported for a large variety of organisms. Pred

  20. Overexpression of patA and patB, which encode ABC transporters, is associated with fluoroquinolone resistance in clinical isolates of Streptococcus pneumoniae.

    Science.gov (United States)

    Garvey, Mark I; Baylay, Alison J; Wong, Ryan L; Piddock, Laura J V

    2011-01-01

    Fifty-seven clinical isolates of Streptococcus pneumoniae were divided into four groups based on their susceptibilities to the fluoroquinolones ciprofloxacin and norfloxacin and the dyes ethidium bromide and acriflavine. Comparative reverse transcription-PCR was used to determine the level of expression of the genes patA and patB, which encode putative ABC transporters. Overexpression was observed in 14 of the 15 isolates that were resistant to both fluoroquinolones and dyes and in only 3 of 24 of those resistant to fluoroquinolones only. Isolates overexpressing patA and patB accumulated significantly less of the fluorescent dye Hoechst 33342 than wild-type isolates, suggesting that PatA and PatB are involved in efflux. Inactivation of patA and patB by in vitro mariner mutagenesis conferred hypersusceptibility to ethidium bromide and acriflavine in all isolates tested and lowered the MICs of ciprofloxacin in the patAB-overproducing and/or fluoroquinolone-resistant isolates. These data represent the first observation of overexpression of patA and patB in clinical isolates and show that PatA and PatB play a clinically relevant role in fluoroquinolone resistance.

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

    Science.gov (United States)

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

    2006-03-23

    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.

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

    Science.gov (United States)

    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.

  3. Role of Ectopic Gene Conversion in the Evolution of a Candida krusei Pleiotropic Drug Resistance Transporter Family

    Science.gov (United States)

    Lamping, Erwin; Zhu, Jing-yi; Niimi, Masakazu; Cannon, Richard David

    2017-01-01

    Gene duplications enable the evolution of novel gene function, but strong positive selection is required to preserve advantageous mutations in a population. This is because frequent ectopic gene conversions (EGCs) between highly similar, tandem-duplicated, sequences, can rapidly remove fate-determining mutations by replacing them with the neighboring parent gene sequences. Unfortunately, the high sequence similarities between tandem-duplicated genes severely hamper empirical studies of this important evolutionary process, because deciphering their correct sequences is challenging. In this study, we employed the eukaryotic model organism Saccharomyces cerevisiae to clone and functionally characterize all 30 alleles of an important pair of tandem-duplicated multidrug efflux pump genes, ABC1 and ABC11, from seven strains of the diploid pathogenic yeast Candida krusei. Discovery and functional characterization of their closest ancestor, C. krusei ABC12, helped elucidate the evolutionary history of the entire gene family. Our data support the proposal that the pleiotropic drug resistance (PDR) transporters Abc1p and Abc11p have evolved by concerted evolution for ∼134 MY. While >90% of their sequences remained identical, very strong purifying selection protected six short DNA patches encoding just 18 core amino acid (aa) differences in particular trans membrane span (TMS) regions causing two distinct efflux pump functions. A proline-kink change at the bottom of Abc11p TMS3 was possibly fate determining. Our data also enabled the first empirical estimates for key parameters of eukaryotic gene evolution, they provided rare examples of intron loss, and PDR transporter phylogeny confirmed that C. krusei belongs to a novel, yet unnamed, third major Saccharomycotina lineage. PMID:28159755

  4. Classification of a Haemophilus influenzae ABC transporter HI1470/71 through its cognate molybdate periplasmic binding protein, MolA.

    Science.gov (United States)

    Tirado-Lee, Leidamarie; Lee, Allen; Rees, Douglas C; Pinkett, Heather W

    2011-11-09

    molA (HI1472) from H. influenzae encodes a periplasmic binding protein (PBP) that delivers substrate to the ABC transporter MolB(2)C(2) (formerly HI1470/71). The structures of MolA with molybdate and tungstate in the binding pocket were solved to 1.6 and 1.7 Å 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 ∼100 μM 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. The presence of two molybdate loci in H. influenzae suggests multiple transport systems for one substrate, with molABC constituting a low-affinity molybdate locus.

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

    Energy Technology Data Exchange (ETDEWEB)

    Tirado-Lee, Leidamarie; Lee, Allen; Rees, Douglas C.; Pinkett, Heather W. (CIT); (NWU)

    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. The presence of two molybdate loci in H. influenzae suggests multiple transport systems for one substrate, with molABC constituting a low-affinity molybdate locus.

  6. Ectoine-induced proteins in Sinorhizobium meliloti include an Ectoine ABC-type transporter involved in osmoprotection and ectoine catabolism.

    Science.gov (United States)

    Jebbar, Mohamed; Sohn-Bösser, Linda; Bremer, Erhard; Bernard, Théophile; Blanco, Carlos

    2005-02-01

    To understand the mechanisms of ectoine-induced osmoprotection in Sinorhizobium meliloti, a proteomic examination of S. meliloti cells grown in minimal medium supplemented with ectoine was undertaken. This revealed the induction of 10 proteins. The protein products of eight genes were identified by using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry. Five of these genes, with four other genes whose products were not detected on two-dimensional gels, belong to the same gene cluster, which is localized on the pSymB megaplasmid. Four of the nine genes encode the characteristic components of an ATP-binding cassette transporter that was named ehu, for ectoine/hydroxyectoine uptake. This transporter was encoded by four genes (ehuA, ehuB, ehuC, and ehuD) that formed an operon with another gene cluster that contains five genes, named eutABCDE for ectoine utilization. On the basis of sequence homologies, eutABCDE encode enzymes with putative and hypothetical functions in ectoine catabolism. Analysis of the properties of ehuA and eutA mutants suggests that S. meliloti possesses at least one additional ectoine catabolic pathway as well as a lower-affinity transport system for ectoine and hydroxyectoine. The expression of ehuB, as determined by measurements of UidA activity, was shown to be induced by ectoine and hydroxyectoine but not by glycine betaine or by high osmolality.

  7. The saci_2123 gene of the hyperthermoacidophile Sulfolobus acidocaldarius encodes an ATP-binding cassette multidrug transporter.

    Science.gov (United States)

    Yang, Nuan; Driessen, Arnold J M

    2015-01-01

    Multidrug resistance (MDR) transporters are capable of secreting structurally and functionally unrelated toxic compounds from the cell. Among this group are ATP-binding cassette (ABC) transporters. These membrane proteins are typically arranged as either hetero- or homo-dimers of ABC half-transporters with each subunit consisting of a membrane domain fused at the C-terminus to an ATP-binding domain, or as full transporters in which the two subunits are fused into a single polypeptide. The saci_2123 gene of the thermoacidophilic archaeon Sulfolobus acidocaldarius is the only gene in the genome that encodes an ATP-binding cassette half-transporter, while a homologous gene is present in the genomes of S. solfataricus, S. tokodaii and S islandicus. Saci_2123 shares homology with well-characterized bacterial and mammalian MDR transporters. The saci_2132 gene is up-regulated when cells are exposed to drugs. A deletion mutant of saci_2132 was found to be more vulnerable to a set of toxic compounds, including detergents, antibiotics and uncouplers as compared to the wild-type strain, while the drug resistance could be restored through the plasmid-based expression of saci_2132. These data demonstrate that Saci_2132 is an archaeal ABC-MDR transporter and therefore it was termed Smr1 (Sulfolobus multidrug resistance transporter 1).

  8. Reciprocal regulation of pyoluteorin production with membrane transporter gene expression in Pseudomonas fluorescens Pf-5.

    Science.gov (United States)

    Brodhagen, Marion; Paulsen, Ian; Loper, Joyce E

    2005-11-01

    Pyoluteorin is a chlorinated polyketide antibiotic secreted by the rhizosphere bacterium Pseudomonas fluorescens Pf-5. Genes encoding enzymes and transcriptional regulators involved in pyoluteorin production are clustered in the genome of Pf-5. Sequence analysis of genes adjacent to the known pyoluteorin biosynthetic gene cluster revealed the presence of an ABC transporter system. We disrupted two putative ABC transporter genes by inserting transcriptional fusions to an ice nucleation reporter gene. Mutations in pltI and pltJ, which are predicted to encode a membrane fusion protein and an ATP-binding cassette of the ABC transporter, respectively, greatly reduced pyoluteorin production by Pf-5. During the transition from exponential growth to stationary phase, populations of a pltI mutant were lower than those of a pltI+ strain in a culture medium containing pyoluteorin, suggesting a role for the transport system in efflux and the resistance of Pf-5 to the antibiotic. Although pltI or pltJ mutant strains displayed low pyoluteorin production, they did not accumulate proportionately more of the antibiotic intracellularly, indicating that pltI and pltJ do not encode an exclusive exporter for pyoluteorin. Transcription of the putative pyoluteorin efflux genes pltI and pltJ was enhanced by exogenous pyoluteorin. These new observations parallel an earlier finding that pyoluteorin enhances the transcription of pyoluteorin biosynthesis genes and pyoluteorin production in Pf-5. This report provides evidence of a coordination of pyoluteorin production and the transcription of genes encoding a linked transport apparatus, wherein each requires the other for optimal expression.

  9. IMG-ABC: new features for bacterial secondary metabolism analysis and targeted biosynthetic gene cluster discovery in thousands of microbial genomes

    Science.gov (United States)

    Hadjithomas, Michalis; Chen, I-Min A.; Chu, Ken; Huang, Jinghua; Ratner, Anna; Palaniappan, Krishna; Andersen, Evan; Markowitz, Victor; Kyrpides, Nikos C.; Ivanova, Natalia N.

    2017-01-01

    Secondary metabolites produced by microbes have diverse biological functions, which makes them a great potential source of biotechnologically relevant compounds with antimicrobial, anti-cancer and other activities. The proteins needed to synthesize these natural products are often encoded by clusters of co-located genes called biosynthetic gene clusters (BCs). In order to advance the exploration of microbial secondary metabolism, we developed the largest publically available database of experimentally verified and predicted BCs, the Integrated Microbial Genomes Atlas of Biosynthetic gene Clusters (IMG-ABC) (https://img.jgi.doe.gov/abc/). Here, we describe an update of IMG-ABC, which includes ClusterScout, a tool for targeted identification of custom biosynthetic gene clusters across 40 000 isolate microbial genomes, and a new search capability to query more than 700 000 BCs from isolate genomes for clusters with similar Pfam composition. Additional features enable fast exploration and analysis of BCs through two new interactive visualization features, a BC function heatmap and a BC similarity network graph. These new tools and features add to the value of IMG-ABC's vast body of BC data, facilitating their in-depth analysis and accelerating secondary metabolite discovery. PMID:27903896

  10. β-Cyclodextrins Decrease Cholesterol Release and ABC-Associated Transporter Expression in Smooth Muscle Cells and Aortic Endothelial Cells

    Science.gov (United States)

    Coisne, Caroline; Hallier-Vanuxeem, Dorothée; Boucau, Marie-Christine; Hachani, Johan; Tilloy, Sébastien; Bricout, Hervé; Monflier, Eric; Wils, Daniel; Serpelloni, Michel; Parissaux, Xavier; Fenart, Laurence; Gosselet, Fabien

    2016-01-01

    -CDs can significantly reduce the cellular cholesterol content of cells forming atherosclerotic lesions and can subsequently modulate the expression of ABC transporters involved in RCT. The use of methylated β-CDs would represent a valuable and efficient tool to interfere with atherosclerosis pathogenesis in patients, nonetheless their mode of action still needs further investigations to be fully understood and finely controlled at the cellular level. PMID:27252658

  11. Pseudomonas aeruginosa capability to recruit zinc under conditions of limited metal availability is affected by inactivation of the ZnuABC transporter

    Science.gov (United States)

    D'Orazio, Melania; Mastropasqua, Maria Chiara; Cerasi, Mauro; Pacello, Francesca; Consalvo, Ada; Chirullo, Barbara; Mortensen, Brittany; Skaar, Eric P.; Ciavardelli, Domenico; Pasquali, Paolo; Battistoni, Andrea

    2015-01-01

    The ability of a large number of bacterial pathogens to multiply in the infected host and cause disease is dependent on their ability to express high affinity zinc importers. In many bacteria ZnuABC, a transporter of the ABC family, plays a central role in the process of zinc uptake in zinc poor environments, including the tissues of the infected host. To initiate an investigation into the relevance of the zinc uptake apparatus for Pseudomonas aeruginosa pathogenicity, we have generated a znuA mutant in the PA14 strain. We have found that this mutant strain displays a limited growth defect in zinc depleted media. The znuA mutant strain is more sensitive than the wild type strain to calprotectin-mediated growth inhibition, but both the strains are highly resistant to this zinc sequestering antimicrobial protein. Moreover, intracellular zinc content is not evidently affected by inactivation of the ZnuABC transporter. These findings suggest that P. aeruginosa is equipped with redundant mechanisms for the acquisition of zinc that might favor P. aeruginosa colonization of environments containing low levels of this metal. Nonetheless, deletion of znuA affects alginate production, reduces the activity of extracellular zinc-containing proteases, including LasA, LasB and Protease IV, and decreases the ability of P. aeruginosa to disseminate during systemic infections. These results indicate that efficient zinc acquisition is critical for the expression of various virulence features typical of P. aeruginosa and that ZnuABC also plays an important role in zinc homeostasis in this microorganism. PMID:25751674

  12. A putative amino acid ABC transporter substrate-binding protein, NMB1612, from Neisseria meningitidis, induces murine bactericidal antibodies against meningococci expressing heterologous NMB1612 proteins.

    Science.gov (United States)

    Hung, Miao-Chiu; Humbert, María Victoria; Laver, Jay R; Phillips, Renee; Heckels, John E; Christodoulides, Myron

    2015-08-26

    The nmb1612 (NEIS1533) gene encoding the ~27-kDa putative amino acid ATP-binding cassette (ABC) transporter, periplasmic substrate-binding protein from Neisseria meningitidis serogroup B (MenB) strain MC58 was cloned and expressed in Escherichia coli, and the purified recombinant (r)NMB1612 was used for animal immunization studies. Immunization of mice with rNMB1612 adsorbed to Al(OH)3 and in liposomes with and without MPLA, induced antiserum with bactericidal activity in an assay using baby rabbit complement, against the homologous strain MC58 (encoding protein representative of Allele 62) and killed heterologous strains encoding proteins of three other alleles (representative of Alleles 1, 64 and 68), with similar SBA titres. However, strain MC58 was not killed (titre protein was killed (median titres of 16-64 in the hSBA). Analysis of the NMB1612 amino acid sequences from 4351 meningococcal strains in the pubmlst.org/Neisseria database and a collection of 13 isolates from colonized individuals and from patients, showed that antibodies raised against rNMB1612 could potentially kill at least 72% of the MenB strains in the complete sequence database. For MenB disease occurring specifically in the UK from 2013 to 2015, >91% of the isolates causing disease in this recent period expressed NMB1612 protein encoded by Allele 1 and could be potentially killed by sera raised to the recombinant antigen in the current study. The NMB1612 protein was surface-accessible and expressed by different meningococcal strains. In summary, the properties of (i) NMB1612 protein conservation and expression, (ii) limited amino acid sequence variation between proteins encoded by different alleles, and (iii) the ability of a recombinant protein to induce cross-strain bactericidal antibodies, would all suggest a promising antigen for consideration for inclusion in new meningococcal vaccines.

  13. Classification of a Haemophilus influenzae ABC transporter HI1470/71 through its cognate molybdate periplasmic binding protein, MolA

    OpenAIRE

    Tirado-Lee, Leidamarie; Lee, Allen; Rees, Douglas C.; Pinkett, Heather W

    2011-01-01

    molA(HI1472) from H. influenzae encodes a periplasmic binding protein (PBP) that delivers substrate to the ABC transporter MolB2C2 (formerly HI1470/71). The structures of MolA with molybdate and tungstate in the binding pocket were solved to 1.6 and 1.7-Å 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 ~100 μM binding affinity...

  14. A role for tungsten in the biology of Campylobacter jejuni: tungstate stimulates formate dehydrogenase activity and is transported via an ultra-high affinity ABC system distinct from the molybdate transporter.

    Science.gov (United States)

    Smart, Jonathan P; Cliff, Matthew J; Kelly, David J

    2009-11-01

    The food-borne pathogen Campylobacter jejuni possesses no known tungstoenzymes, yet encodes two ABC transporters (Cj0300-0303 and Cj1538-1540) homologous to bacterial molybdate (ModABC) uptake systems and the tungstate transporter (TupABC) of Eubacterium acidaminophilum respectively. The actual substrates and physiological role of these transporters were investigated. Tryptophan fluorescence spectroscopy and isothermal titration calorimetry of the purified periplasmic binding proteins of each system revealed that while Cj0303 is unable to discriminate between molybdate and tungstate (K(D) values for both ligands of 4-8 nM), Cj1540 binds tungstate with a K(D) of 1.0 +/- 0.2 pM; 50 000-fold more tightly than molybdate. Induction-coupled plasma mass spectroscopy of single and double mutants showed that this large difference in affinity is reflected in a lower cellular tungsten content in a cj1540 (tupA) mutant compared with a cj0303c (modA) mutant. Surprisingly, formate dehydrogenase (FDH) activity was decreased approximately 50% in the tupA strain, and supplementation of the growth medium with tungstate significantly increased FDH activity in the wild type, while inhibiting known molybdoenzymes. Our data suggest that C. jejuni possesses a specific, ultra-high affinity tungstate transporter that supplies tungsten for incorporation into FDH. Furthermore, possession of two MoeA paralogues may explain the formation of both molybdopterin and tungstopterin in this bacterium.

  15. Genetic organisation of the capsule transport gene region from Haemophilus paragallinarum

    Directory of Open Access Journals (Sweden)

    O. De Smidt

    2004-11-01

    Full Text Available The region involved in export of the capsule polysaccharides to the cell surface of Haemophilus paragallinarum was cloned and the genetic organisation determined. Degenerate primers designed from sequence alignment of the capsule transport genes of Haemophilus influenzae, Pasteurella multocida and Actinobacillus pleuropneumoniae were used to amplify a 2.6 kb fragment containing a segment of the H. paragallinarum capsule transport gene locus. This fragment was used as a digoxigenin labelled probe to isolate the complete H. paragallinarum capsule transport gene locus from genomic DNA. The sequence of the cloned DNA was determined and analysis revealed the presence of four genes, each showing high homology with known capsule transport genes. The four genes were designated hctA, B, C and D (for H. paragallinarum capsule transport genes and the predicted products of these genes likely encode an ATP-dependent export system responsible for transport of the capsule polysaccharides to the cell surface, possibly a member of a super family designated ABC (ATP-binding cassette transporters.

  16. Functional characterization of the Bradyrhizobium japonicum modA and modB genes involved in molybdenum transport.

    Science.gov (United States)

    Delgado, María J; Tresierra-Ayala, Alvaro; Talbi, Chouhra; Bedmar, Eulogio J

    2006-01-01

    A modABC gene cluster that encodes an ABC-type, high-affinity molybdate transporter from Bradyrhizobium japonicum has been isolated and characterized. B. japonicum modA and modB mutant strains were unable to grow aerobically or anaerobically with nitrate as nitrogen source or as respiratory substrate, respectively, and lacked nitrate reductase activity. The nitrogen-fixing ability of the mod mutants in symbiotic association with soybean plants grown in a Mo-deficient mineral solution was severely impaired. Addition of molybdate to the bacterial growth medium or to the plant mineral solution fully restored the wild-type phenotype. Because the amount of molybdate required for suppression of the mutant phenotype either under free-living or under symbiotic conditions was dependent on sulphate concentration, it is likely that a sulphate transporter is also involved in Mo uptake in B. japonicum. The promoter region of the modABC genes has been characterized by primer extension. Reverse transcription and expression of a transcriptional fusion, P(modA)-lacZ, was detected only in a B. japonicum modA mutant grown in a medium without molybdate supplementation. These findings indicate that transcription of the B. japonicum modABC genes is repressed by molybdate.

  17. Detergent screening and purification of the human liver ABC transporters BSEP (ABCB11 and MDR3 (ABCB4 expressed in the yeast Pichia pastoris.

    Directory of Open Access Journals (Sweden)

    Philipp Ellinger

    Full Text Available 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.

  18. Detection of AdeABC efflux pump genes in tetracycline-resistant Acinetobacter baumannii isolates from burn and ventilator-associated pneumonia patients

    Directory of Open Access Journals (Sweden)

    Maryam Beheshti

    2014-01-01

    Full Text Available Purpose: Acinetobacter baumannii is the most prevalent nosocomial pathogen which have been emerged in the past three decades worldwide. The aim of this study was to assess the distribution of the AdeABC efflux pump genes, associated with tetracycline resistance in Acinetobacter baumannii isolates collected from burn infection and Ventilator Associated Pneumonia (VAP. Materials and Methods: Ninety-eight A. baumannii isolates were collected from two different hospitals in Tehran, Iran. Tetracycline susceptibility testing was performed by disk diffusion and agar dilution methods according to the CLSI guidelines. The presence of adeSR, adeB, drug efflux system genes in resistant isolates was assessed by polymerase chain reaction (PCR. Carbonyl cyanide 3-chlorophenylhydrazone (CCCP was used as a chemical inhibitor agent to assess the contribution of AdeABC efflux pump in tetracycline resistance isolates. Results: Approximately 48% (47 out of 98 of isolates showed resistance to tetracycline which 14 (14.2% isolates were corresponded to burn infection and the remaining 33 (33.8% strains were isolated from VAP. All tetracycline resistant isolates have AdeABC in PCR assay. The reduction of tetracycline MICs by using 50 μg/ml CCCP were as follows: in 18 isolates 2-4 fold reduction in MICs, 26 isolates showed 8 fold reduction,1 isolate showed 16 fold, 1 isolate showed 32 fold and the remaining 1 isolate showed 128 fold reduction in MICs. Conclusion: The results showed significant correlation between tetracycline resistance and AdeABC efflux pump genes in resistant A. baumannii isolates.

  19. Identification and characterization of ectoine biosynthesis genes and heterologous expression of the ectABC gene cluster from Halomonas sp. QHL1, a moderately halophilic bacterium isolated from Qinghai Lake.

    Science.gov (United States)

    Zhu, Derui; Liu, Jian; Han, Rui; Shen, Guoping; Long, Qifu; Wei, Xiaoxing; Liu, Deli

    2014-02-01

    The moderately halophilic bacterium Halomonas sp. QHL1 was identified as a member of the genus Halomonas by 16S rRNA gene sequencing. HPLC analysis showed that strain QHL1 synthesizes ectoine in its cytoplasm. The genes involved in the ectoine biosynthesis pathway were identified on the chromosome in the order ectABC. Subsequently, the ectB gene from this strain was amplified by PCR, and the entire ectABC gene cluster (3,580 bp) was cloned using genome walking. Analysis showed that the ectA (579 bp), ectB (1269 bp), and ectC (390 bp) genes were organized in a single transcriptional unit and were predicted to encode three peptides of 21.2 kDa, 46.4 kDa, and 14.7 kDa, respectively. Two putative promoters, a δ(70)-dependent promoter and a δ(38)-controlled promoter, as well as several conserved motifs with unknown function were identified. Individual ectA, ectB, and ectC genes, and the entire ectABC gene cluster were inserted into the expression plasmid pET-28a(+) to generate the recombinant plasmids pET-28a(+)-ectA, pET-28a(+)-ectB, pET-28a(+)-ectC and pET-28a(+)-ectABC, respectively. Heterologous expression of these proteins in Escherichia coli BL21 (DE3) was confirmed by SDS-PAGE. The recombinant E. coli strain BL21 (pET-28a (+)-ectABC) displayed a higher salt tolerance than native E. coli cells but produced far less ectoine than the wild-type QHL1 strain.

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

    Directory of Open Access Journals (Sweden)

    Kiyoko Kaneko

    2013-11-01

    Full Text Available 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.

  1. Therapeutic potential of inhibiting ABCE1 and eRF3 genes via siRNA strategy using chitosan nanoparticles in breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Cengiz, Bagdat Burcu; Asik, Mehmet Dogan [Hacettepe University, Nanotechnology and Nanomedicine Division (Turkey); Kara, Goknur [Hacettepe University, Biochemistry Division, Chemistry Department (Turkey); Turk, Mustafa [Kirikkale University, Bioengineering Department (Turkey); Denkbas, Emir Baki, E-mail: denkbas@hacettepe.edu.tr [Hacettepe University, Biochemistry Division, Chemistry Department (Turkey)

    2015-04-15

    In recent years, targeted cancer therapy strategies have begun to take the place of the conventional treatments. Inhibition of the specific genes, involved in cancer progress, via small interfering RNA (siRNA) has become one of the promising therapeutic approaches for cancer therapy. However, due to rapid nuclease degradation and poor cellular uptake of siRNA, a suitable carrier for siRNA penetration inside the cells is required. We used chitosan nanoparticles (CS-NPs) to efficiently deliver ATP-binding casette E1 (ABCE1) and eukaryotic release factor 3 (eRF3)-targeting siRNAs, individually and together, to reduce the proliferation and induce the apoptosis of breast cancer cells. The CS-NPs were generated by ionic gelation method using tripolyphosphate (TPP) as a crosslinker. Nanoparticles (NPs) were obtained with diameters ranging between 110 and 230 nm and the zeta potential of approximately 27 mV optimizing the solution pH to 4.5 and CS/TPP mass ratio to 3:1. Loading efficiencies of 98.69 % ± 0.051 and 98.83 % ± 0.047 were achieved when ABCE1 siRNA and eRF3 siRNA were entrapped into the NPs, respectively. Cell proliferation assay demonstrated that siRNA-loaded CS-NPs were more effective on cancer cells when compared to siRNAs without CS-NPs. Parallel results were also obtained by apoptosis/necrosis, double-staining analysis. Within our study, the potency of ABCE1 and eRF3 siRNAs were shown for the first time with this kind of polymeric delivery system. The results also indicated that ABCE1 and eRF3, important molecules in protein synthesis, could serve as effective targets to inhibit the cancer cells.

  2. Effect of iron on expression of efflux pump (adeABC) and quorum sensing (luxI, luxR) genes in clinical isolates of Acinetobacter baumannii.

    Science.gov (United States)

    Modarresi, Farzan; Azizi, Omid; Shakibaie, Mohammad Reza; Motamedifar, Mohammad; Valibeigi, Behnaz; Mansouri, Shahla

    2015-11-01

    Resistance-nodulation-division efflux system (RND) adeABC contributes to intrinsic resistance to various drug classes in Acinetobacter baumannii. Similarly, quorum sensing (QS) plays an important role in the biofilm formation and pathogenicity of this bacterium. The aims of this study were to evaluate the influence of iron limitation on the expression of efflux pump (adeABC) genes and QS (luxI, luxR) system by relative quantitative real-time polymerase chain reaction (qRT-PCR). In addition, DNA sequence and phylogenetic relatedness of biofilm-associated protein (Bap) gene was also investigated. Sixty-five multidrug-resistant isolates of A. baumannii were recovered from ICU patients of three hospitals in Kerman, Iran. The isolates were highly resistant to at least 11 antibiotics (MIC ≥64 μg/mL); however, 87% and 89% were susceptible to colistin and tigecycline, respectively (MIC 0.05 μg/mL) (p ≤ 0.05). We detected the presence of RND efflux pump, QS, and bap genes with the frequencies of 92% (adeA), 61.5% (adeB), 84.6% (adeC), 80% (luxI), 61% (luxR), and 66% (bap), respectively. qRT-PCR analysis showed that in some isolates, expression of both adeABC and luxI/R was increased more than fourfold in the presence of low iron (20 μm), suggesting the additional regulatory role of iron on both efflux pump and QS system. Alignment and phylogenetic analysis on the strong biofilm forming isolates confirmed that the fragments amplified were indeed part of bap gene and deduced sequence was similar to A. baumannii K9B410.

  3. ABC Technology Development Program

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-10-14

    The Accelerator-Based Conversion (ABC) facility will be designed to accomplish the following mission: `Provide a weapon`s grade plutonium disposition capability in a safe, economical, and environmentally sound manner on a prudent schedule for [50] tons of weapon`s grade plutonium to be disposed on in [20] years.` This mission is supported by four major objectives: provide a reliable plutonium disposition capability within the next [15] years; provide a level of safety and of safety assurance that meets or exceeds that afforded to the public by modern commercial nuclear power plants; meet or exceed all applicable federal, state, and local regulations or standards for environmental compliance; manage the program in a cost effective manner. The ABC Technology Development Program defines the technology development activities that are required to accomplish this mission. The technology development tasks are related to the following topics: blanket system; vessel systems; reactivity control systems; heat transport system components; energy conversion systems; shutdown heat transport systems components; auxiliary systems; technology demonstrations - large scale experiments.

  4. Molecular detection of AdeABC efflux pump genes in clinical isolates of Acinetobacter baumannii and their contribution in imipenem resistance

    Directory of Open Access Journals (Sweden)

    Ali Reza JaponiNejad

    2014-11-01

    Full Text Available Backgrand: Multi-drug resistance due to Acinetobacter baumannii strains has become a significant challenge. Efflux pump plays a vital role in the development of resistance in this bacteria. The aim of this study was to evaluate the frequency of the AdeABC efflux pump genes and its role in resistance to imipenem in clinical isolates of A.baumannii. Materials and methods: A total of 56 isolates of A.baumannii were collected from different clinical specimens of Valiasr hospital in the Arak –Iran and all isolates were identified by standard biochemical tests. The Antimicrobial susceptibility patterns were determined by disk diffusion method and minimum inhibitory concentrations of imipenemin via E-test strips with and without CCCP efflux pump inhibitor were determined according to CLSI guidelines. The PCR test was used to detect the AdeABC efflux pump genes in isolates. Results: All A.bumannii isolates were resistant to cefotaxim, ceftazidim, cefepim, cefoxitin, azteronam, piperacillin-tazobactam and ciprofloxacin, as well as all isolates were resistant to imipenem according to the results of the E-test method. Imipenem MIC with efflux pump inhibitor not reduced in all isolates and showed no differences in imipenem activity. The adeA, adeB and adeC genes were found in 100%, 100% and 96.5% of isolates, respectively. Conclusion: AdeABC efflux system contributes to resistance to other antibiotics and resistance to imipenem has not been involved with this efflux system in A.baumanni isolates in current study and other mechanism such as carbapenemase enzymes play vital role to imipenem resistance in A.baumanni isolates.

  5. [Cloning of the ectoine biosynthesis gene ectABC from Halomonas sp. BYS-1 and salt stressed expression in Escherichia coli].

    Science.gov (United States)

    He, Jian; Huang, Xing; Gu, Li-feng; Jiang, Jian-dong; Li, Shun-peng

    2006-02-01

    Ectoine was the main compatible solute of moderately halophilic bacteria. In order to clone the ectABC gene which involved in the ectoine biosynthesis pathway from total DNA of moderately halophilic bacteria Halomonas sp. BYS-1, firstly a 750bp fragment of ectABC gene was amplified by PCR using combinations of forward primers and reverse primers designed according to the ectABC genes of Halomonas elongata 2851T and Halomonas elongata DSM3043. Then the upstream and downstream sequences of the 750bp fragment were amplified by SEFA PCR (SElf-Formed Adaptor PCR), a new PCR method amplified relatively long flanking sequences from tagged sequences in a simple way without enzyme excision and ligation. The 3532bp fragment include 2423bp ectABC, 980bp upstream sequences and 129bp downstream sequences were cloned from Halomonas sp. BYS-1 using a pair of conserved primers designed according to acquired sequences by SEFA PCR. The GenBank accession number of the 3532bp fragment is DQ017757. ORF analysis revealed that ectA, ectB, ectC cluster to an operon, the size of ectA, ectB, and ectC were 573bp, 1251bp and 387bp respectively. The predicted molecular masses of the encoded proteins were 21.1kDa (191 amino acids, EctA), 45.7 kDa (417 amino acids, EctB), and 14.5 kDa (129 amino acids, EctC) respectively. The 3532bp fragment was ligated to the MCS site of vector pUC19 and transformed E. coli DH5alpha to construct E. coli (pUC19ECT). Transformant E. coli (pUC19ECT) could synthesis ectoine under salt stress, the intracellular ectoine level were 7.1, 19.4 and 32.3 micromol/(g x dry x wt) when the salinities of the mediums were 0, 0.4 and 0.8mol/L sodium chloride respectively. But the accumulation of ectoine could not promote the growth of E. coli (pUC19ECT)under high salinity.

  6. Dual fluorescent labelling of the human malaria parasite Plasmodium falciparum for the analysis of the ABC type transporter pfmdr2

    Directory of Open Access Journals (Sweden)

    Rosental Benyamin

    2012-11-01

    Full Text Available Abstract Background The study of the Plasmodium falciparum heavy metal transporter gene pfmdr2 employed radioactive labelled heavy metal. As the use of radioactive isotopes shrank considerably during the last few years, resulting in the cessation of the production of some isotopes, amongst them Cadmium109 which was used for that purpose, a different approach had to be developed. Herein, a dual fluorescent labelling of heavy metals accumulation in the P. falciparum parasite is proposed as an alternative to the use of radioactive labelled heavy metals. Methods Plasmodium falciparum Cd resistant and sensitive strains at the trophozoite stage were used in this study. The cells were cultured at different CdCl2 concentrations and for different time periods followed by staining of the infected red blood cells with Fluo-3/AM for Cd detection and Hoechst 33342 for parasite DNA labelling. The fluorescent analysis was done by flow cytometry and confocal microscopy. Results The results show that the sensitive strain has a higher Fluo-3/AM fluorescence in a Cd concentration and time dependent manner, whereas in the resistant strain Fluo-3/AM fluorescence levels were negligible and increased only at high concentrations of Cd and at long incubation periods, but to a much lesser extent than the sensitive strain. No Cd uptake is observed in uninfected red blood cells populations originating from cultures infected with either sensitive or resistant strain. In addition, confocal microscopy overlay of Fluo-3/AM and Hoechst staining shows that the Cd metal accumulates in the parasite itself. Conclusions The dual fluorescent labelling is a valid method for detecting heavy metal accumulation in P. falciparum. Furthermore, in contrast to the use of radioactive labelled heavy metal, the fluorescent labelling enables us to differentiate between the different populations existing in a P. falciparum infected red blood cells cultures and thus actually study a phenomenon at

  7. The Nucleotide-Free State of the Multidrug Resistance ABC Transporter LmrA: Sulfhydryl Cross-Linking Supports a Constant Contact, Head-to-Tail Configuration of the Nucleotide-Binding Domains.

    Directory of Open Access Journals (Sweden)

    Peter M Jones

    Full Text Available ABC transporters are integral membrane pumps that are responsible for the import or export of a diverse range of molecules across cell membranes. ABC transporters have been implicated in many phenomena of medical importance, including cystic fibrosis and multidrug resistance in humans. The molecular architecture of ABC transporters comprises two transmembrane domains and two ATP-binding cassettes, or nucleotide-binding domains (NBDs, which are highly conserved and contain motifs that are crucial to ATP binding and hydrolysis. Despite the improved clarity of recent structural, biophysical, and biochemical data, the seemingly simple process of ATP binding and hydrolysis remains controversial, with a major unresolved issue being whether the NBD protomers separate during the catalytic cycle. Here chemical cross-linking data is presented for the bacterial ABC multidrug resistance (MDR transporter LmrA. These indicate that in the absence of nucleotide or substrate, the NBDs come into contact to a significant extent, even at 4°C, where ATPase activity is abrogated. The data are clearly not in accord with an inward-closed conformation akin to that observed in a crystal structure of V. cholerae MsbA. Rather, they suggest a head-to-tail configuration 'sandwich' dimer similar to that observed in crystal structures of nucleotide-bound ABC NBDs. We argue the data are more readily reconciled with the notion that the NBDs are in proximity while undergoing intra-domain motions, than with an NBD 'Switch' mechanism in which the NBD monomers separate in between ATP hydrolysis cycles.

  8. An ABC transporter and a TonB ortholog contribute to Helicobacter mustelae nickel and cobalt acquisition

    NARCIS (Netherlands)

    J. Stoof (Jeroen); E.J. Kuipers (Ernst); G. Klaver (Gerard); A.H.M. van Vliet (Arnoud)

    2010-01-01

    textabstractThe genomes of Helicobacter species colonizing the mammalian gastric mucosa (like Helicobacter pylori) contain a large number of genes annotated as iron acquisition genes but only few nickel acquisition genes, which contrasts with the central position of nickel in the urease-mediated aci

  9. An ABC transporter and a TonB ortholog contribute to Helicobacter mustelae nickel and cobalt acquisition

    NARCIS (Netherlands)

    Stoof, J.; Kuipers, E.J.; Klaver, G.; Vliet, A.H.M. van

    2010-01-01

    The genomes of Helicobacter species colonizing the mammalian gastric mucosa (like Helicobacter pylori) contain a large number of genes annotated as iron acquisition genes but only few nickel acquisition genes, which contrasts with the central position of nickel in the urease-mediated acid resistance

  10. The saci_2123 gene of the hyperthermoacidophile Sulfolobus acidocaldarius encodes an ATP-binding cassette multidrug transporter

    NARCIS (Netherlands)

    Yang, Nuan; Driessen, Arnold J. M.

    2015-01-01

    Multidrug resistance (MDR) transporters are capable of secreting structurally and functionally unrelated toxic compounds from the cell. Among this group are ATP-binding cassette (ABC) transporters. These membrane proteins are typically arranged as either hetero- or homo-dimers of ABC half-transporte

  11. Struktur von ABCE1

    OpenAIRE

    Karcher, Annette

    2007-01-01

    ABCE1 ist ein Mitglied der ATP Binding Cassette (ABC) Superfamilie. ABC Proteine binden und hydrolysieren ATP und verändern dabei ihre Konformation. Dadurch können sie mechanochemische Arbeit leisten. Durch drei zusätzliche Domänen unterscheidet sich ABCE1 von allen bislang bekannten und charakterisierten Mitgliedern dieser Familie. Neben den ATP-bindenden Regionen enthält ABCE1 eine cysteinreiche, N-terminale Domäne, welche zwei Eisen-Schwefel-Cluster bindet. Diese Domäne hat hohe s...

  12. ABCA Transporter Gene Expression and Poor Outcome in Epithelial Ovarian Cancer

    DEFF Research Database (Denmark)

    Hedditch, Ellen L; Gao, Bo; Russell, Amanda J

    2014-01-01

    -wide association study. Impact of short interfering RNA-mediated gene suppression was determined by colony forming and migration assays. Association with survival was assessed with Kaplan-Meier analysis and log-rank tests. All statistical tests were two-sided. RESULTS: Associations with outcome were observed...... with ABC transporters of the "A" subfamily, but not with multidrug transporters. High-level expression of ABCA1, ABCA6, ABCA8, and ABCA9 in primary tumors was statistically significantly associated with reduced survival in serous ovarian cancer patients. Low levels of ABCA5 and the C-allele of rs536009...... cancer cell growth and migration in vitro, and statin treatment reduced ovarian cancer cell migration. CONCLUSIONS: Expression of ABCA transporters was associated with poor outcome in serous ovarian cancer, implicating lipid trafficking as a potentially important process in EOC....

  13. Polymorphisms in ATP-binding cassette transporter genes and interaction with diet and life style factors in relation to colorectal cancer in a Danish prospective case-cohort study

    DEFF Research Database (Denmark)

    Kopp, Tine Iskov; Andersen, Vibeke; Tjonneland, Anne;

    2015-01-01

    The ATP-binding cassette (ABC) transporter family transports various molecules across the enterocytes in the gut protecting the intestine against potentially harmful substances. Moreover, ABC transporters are involved in mucosal immune defence through interaction with cytokines. The study aimed...

  14. Ectoine-Induced Proteins in Sinorhizobium meliloti Include an Ectoine ABC-Type Transporter Involved in Osmoprotection and Ectoine Catabolism

    OpenAIRE

    Jebbar, Mohamed; Sohn-Bösser, Linda; Bremer, Erhard; Bernard, Théophile; Blanco, Carlos

    2005-01-01

    To understand the mechanisms of ectoine-induced osmoprotection in Sinorhizobium meliloti, a proteomic examination of S. meliloti cells grown in minimal medium supplemented with ectoine was undertaken. This revealed the induction of 10 proteins. The protein products of eight genes were identified by using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry. Five of these genes, with four other genes whose products were not detected on two-dimensional gels, belong to th...

  15. RNAI-based gene therapy of hepatocellular carcinoma: targeting ABC transporters

    NARCIS (Netherlands)

    Borel, F.

    2012-01-01

    Hepatocellular carcinoma (HCC) is a primary cancer of the liver, and HCC patients have an average survival of only 5% at 5-year post-diagnosis. This low survival has several identified causes, among which multidrug resistance i.e. resistance to chemotherapeutic treatment. These issues need be addres

  16. ABC Kinga kauplused = ABC King shoe stores

    Index Scriptorium Estoniae

    2011-01-01

    Tallinnas Kristiine keskuses, Tartu Kaubamajas ja Pärnus Port Artur 2 asuvate ABC Kinga kaupluste sisekujundusest. Sisearhitekid Andres Labi ja Janno Roos (Ruumilabor OÜ), loetletud nende ühiselt tehtud töid

  17. Genome-wide identification and characterization of ATP-binding cassette transporters in the silkworm, Bombyx mori

    Directory of Open Access Journals (Sweden)

    Zhang Jianzhen

    2011-10-01

    Full Text Available Abstract Background The ATP-binding cassette (ABC transporter superfamily is the largest transporter gene family responsible for transporting specific molecules across lipid membranes in all living organisms. In insects, ABC transporters not only have important functions in molecule transport, but also play roles in insecticide resistance, metabolism and development. Results From the genome of the silkworm, Bombyx mori, we have identified 51 putative ABC genes which are classified into eight subfamilies (A-H by phylogenetic analysis. Gene duplication is very evident in the ABCC and ABCG subfamilies, whereas gene numbers and structures are well conserved in the ABCD, ABCE, ABCF, and ABCH subfamilies. Microarray analysis revealed that expression of 32 silkworm ABC genes can be detected in at least one tissue during different developmental stages, and the expression patterns of some of them were confirmed by quantitative real-time PCR. A large number of ABC genes were highly expressed in the testis compared to other tissues. One of the ABCG genes, BmABC002712, was exclusively and abundantly expressed in the Malpighian tubule implying that BmABC002712 plays a tissue-specific role. At least 5 ABCG genes, including BmABC005226, BmABC005203, BmABC005202, BmABC010555, and BmABC010557, were preferentially expressed in the midgut, showing similar developmental expression profiles to those of 20-hydroxyecdysone (20E-response genes. 20E treatment induced the expression of these ABCG genes in the midgut and RNA interference-mediated knockdown of USP, a component of the 20E receptor, decreased their expression, indicating that these midgut-specific ABCG genes are 20E-responsive. Conclusion In this study, a genome-wide analysis of the silkworm ABC transporters has been conducted. A comparison of ABC transporters from 5 insect species provides an overview of this vital gene superfamily in insects. Moreover, tissue- and stage-specific expression data of the

  18. Human proton/oligopeptide transporter (POT) genes

    DEFF Research Database (Denmark)

    Botka, C. W.; Wittig, T. W.; Graul, R. C.

    2000-01-01

    The proton-dependent oligopeptide transporters (POT) gene family currently consists of approximately 70 cloned cDNAs derived from diverse organisms. In mammals, two genes encoding peptide transporters, PepT1 and PepT2 have been cloned in several species including humans, in addition to a rat...... the presence of several possible splice variants of hPHT1. A second closely related human EST-contig displayed high identity to a recently cloned mouse cDNA encoding cyclic adenosine monophosphate (cAMP)-inducible 1 protein (gi:4580995). This contig served to identify a PAC clone containing deduced exons...

  19. The C-terminus of nisin is important for the ABC transporter NisFEG to confer immunity in Lactococcus lactis.

    Science.gov (United States)

    AlKhatib, Zainab; Lagedroste, Marcel; Zaschke, Julia; Wagner, Manuel; Abts, André; Fey, Iris; Kleinschrodt, Diana; Smits, Sander H J

    2014-10-01

    The lantibiotic nisin is a small 3.4 kDa antimicrobial peptide, which acts against Gram-positive bacteria in the nmol/L range. Nisin is produced and secreted by several Lactococcus lactis strains to ensure advantages against other bacteria in their habitat. Nisin contains five specific lanthionine rings of which the first two are important for Lipid II binding and the last two are crucial for the pore formation in the membrane. To gain immunity against nisin, the producing strain is expressing an ABC transporter called NisFEG, which expels nisin from the membrane. As a result six to eightfold more nisin is needed to affect the cells. The hydrolysis of ATP by NisFEG is required for this immunity as shown by a mutant, where the ATP hydrolysis is disrupted (NisFH181A EG). Furthermore, NisFEG recognizes the C-terminus of nisin, since deletion of the last six amino acids as well as of the last ring lowered the fold of immunity displayed by NisFEG.

  20. The function of the ATP-binding cassette (ABC) transporter ABCB1 is not susceptible to actin disruption

    NARCIS (Netherlands)

    Meszaros, Peter; Hummel, Ina; Klappe, Karin; Draghiciu, Oana; Hoekstra, Dick; Kok, Jan W.

    2013-01-01

    Previously we have shown that the activity of the multidrug transporter ABCC1 (multidrug resistance protein 1), and its localization in lipid rafts, depends on cortical actin (Hummel I, Klappe K, Ercan C, Kok JW. Mol. Pharm. 2011 79, 229-40). Here we show that the efflux activity of the ATP-binding

  1. Multidrug resistance mediated by ABC transporters in osteosarcoma cell lines: mRNA analysis and functional radiotracer studies

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Celia Maria Freitas [Department of Pathology, Leiden University Medical Center, 2300 RC Leiden (Netherlands); Faculty of Medicine, Institute of Biophysics/Biomathematics, IBILI, 3000-354 Coimbra (Portugal)]. E-mail: cgomes@ibili.uc.pt; van Paassen, Heidi [Department of Pathology, Leiden University Medical Center, 2300 RC Leiden (Netherlands); Romeo, Salvatore [Department of Pathology, Leiden University Medical Center, 2300 RC Leiden (Netherlands); Welling, Mick M. [Department of Radiology, Section of Nuclear Medicine, Leiden University Medical Center, 2300 RC Leiden (Netherlands); Feitsma, R.I.J. [Department of Radiology, Section of Nuclear Medicine, Leiden University Medical Center, 2300 RC Leiden (Netherlands); Abrunhosa, Antero J. [Faculty of Medicine, Institute of Biophysics/Biomathematics, IBILI, 3000-354 Coimbra (Portugal); Botelho, M. Filomena [Faculty of Medicine, Institute of Biophysics/Biomathematics, IBILI, 3000-354 Coimbra (Portugal); Hogendoorn, Pancras C.W. [Department of Pathology, Leiden University Medical Center, 2300 RC Leiden (Netherlands); Pauwels, Ernest [Department of Radiology, Section of Nuclear Medicine, Leiden University Medical Center, 2300 RC Leiden (Netherlands); Cleton-Jansen, Anne Marie [Department of Pathology, Leiden University Medical Center, 2300 RC Leiden (Netherlands)

    2006-10-15

    Drug resistance remains a significant impediment to successful chemotherapy and constitutes a major prognostic factor in osteosarcoma (OS) patients. This study was designed to identify the role and prognostic significance of multidrug-resistance (MDR)-related transporters, such as multidrug resistance protein 1 (MDR1), multidrug-resistance-associated protein (MRP1) and breast-cancer-related protein (BCRP), in OS using cationic lipophilic radiotracers. We evaluated the chemosensitivity of four OS cell lines (Saos-2, 143B, MNNG/HOS and U-2OS) to doxorubicin (DOX), cisplatin (CIS) and methotrexate. The expression of MDR-related transporters was analyzed at mRNA level by quantitative polymerase chain reaction and at functional level by {sup 99m}Tc sestamibi and {sup 99m}Tc tetrofosmin. The effectiveness of MDR modulators [cyclosporin A (CsA) and imatinib] on transporter inhibition and on the reversal of resistance was also assessed. MNNG/HOS and U-2OS cells expressing high levels of MDR1 were highly resistant to DOX and showed reduced accumulation and higher efflux for radiotracers. Although MRP1 was uniformly expressed in all cells, only U-2OS was resistant to CIS. CsA restored sensitivity to DOX and CIS, and enhanced the accumulation and efflux half-life of radiotracers in MDR1-expressing cell lines. The chemosensitivity of OS cells to DOX was strongly dependent on mRNA MDR1 expression and could be circumvented by adding CsA. The kinetic parameters of radiotracers correlated with MDR1 expression levels, hence predicting DOX resistance. We concluded that sensitivity to chemotherapy is strongly dependent on the expression of MDR1 transporter and that radiotracer studies could prove clinically useful in predicting chemotherapy response and in evaluating the efficacy of MDR-reversing agents.

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

    Science.gov (United States)

    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.

  3. The ABC transporter HrtAB confers resistance to hemin toxicity and is regulated in a hemin-dependent manner by the ChrAS two-component system in Corynebacterium diphtheriae.

    Science.gov (United States)

    Bibb, Lori A; Schmitt, Michael P

    2010-09-01

    Corynebacterium diphtheriae, the causative agent of the severe respiratory disease diphtheria, utilizes hemin and hemoglobin as iron sources for growth in iron-depleted environments. Because of the toxicity of high levels of hemin and iron, these compounds are often tightly regulated in bacterial systems. In this report, we identify and characterize the C. diphtheriae hrtAB genes, which encode a putative ABC type transporter involved in conferring resistance to the toxic effects of hemin. Deletion of the hrtAB genes in C. diphtheriae produced increased sensitivity to hemin, which was complemented by a plasmid harboring the cloned hrtAB locus. The HrtAB system was not involved in the uptake and use of hemin as an iron source. The hrtAB genes are located on the C. diphtheriae genome upstream from the chrSA operon, which encodes a previously characterized two-component signal transduction system that regulates gene expression in a heme-dependent manner. The hrtB promoter is activated by the ChrAS system in the presence of hemin or hemoglobin, and mutations in the chrSA genes abolish heme-activated expression from the hrtB promoter. It was also observed that transcription from the hrtB promoter is reduced in a dtxR deletion mutant, suggesting that DtxR is required for optimal expression of hrtAB. Previous studies proposed that the ChrS sensor kinase may be responsive to an environmental signal, such as hemin. We show that specific point mutations in the ChrS N-terminal transmembrane domain result in a reduced ability to activate the hrtB promoter in the presence of a heme source, suggesting that this putative sensor region is essential for the detection of a signal produced in response to hemin exposure. This study shows that the HrtAB system is required for protection from hemin toxicity and that expression of the hrtAB genes is regulated by the ChrAS two-component system. This study demonstrates a direct correlation between the detection of heme or a heme

  4. The Escherichia coli TatABC system and a Bacillus subtilis TatAC-type system recognise three distinct targeting determinants in twin-arginine signal peptides

    NARCIS (Netherlands)

    Mendel, Sharon; McCarthy, Andrew; Barnett, James P.; Eijlander, Robyn T.; Nenninger, Anja; Kuipers, Oscar P.; Robinson, Colin

    2008-01-01

    The Tat system transports folded proteins across bacterial and thylakoid membranes. In Gram-negative organisms, it is encoded by tatABC genes and the system recognizes substrates bearing signal peptides with a conserved twin-arginine motif. Most Gram-positive organisms lack a tatB gene, indicating m

  5. Sulfur source-mediated transcriptional regulation of the rhlABC genes involved in biosurfactants production by Pseudomonas sp. strain AK6U.

    Science.gov (United States)

    Ismail, Wael; El Nayal, Ashraf M; Ramadan, Ahmed R; Abotalib, Nasser

    2014-01-01

    Despite the nutritional significance of sulfur, its influence on biosurfactants production has not been sufficiently studied. We investigated the expression of key biosurfactants production genes, rhlABC, in cultures of Pseudomonas sp. AK6U grown with inorganic or organic sulfur sources. AK6U grew with either inorganic sulfate (MgSO4), dibenzothiophene (DBT), or DBT-sulfone as a sole sulfur source in the presence of glucose as a carbon source. The AK6U cultures produced variable amounts of biosurfactants depending on the utilized sulfur source. Biosurfactants production profile of the DBT cultures was significantly different from that of the DBT-sulfone and inorganic sulfate cultures. The last two cultures were very similar in terms of biosurfactants productivity. Biosurfactants yield in the DBT cultures (1.3 g/L) was higher than that produced by the DBT-sulfone (0.5 g/L) and the inorganic sulfate (0.44 g/L) cultures. Moreover, the surface tension reduction in the DBT cultures (33 mN/m) was much stronger than that measured in the DBT-sulfone (58 mN/m) or inorganic sulfate (54 mN/m) cultures. RT-qPCR revealed variations in the expression levels of the rhlABC genes depending on the sulfur source. The DBT cultures had higher expression levels for the three genes as compared to the DBT-sulfone and inorganic sulfate cultures. There was no significant difference in the expression profiles between the DBT-sulfone and the MgSO4 cultures. The increased expression of rhlC in the DBT cultures is indicative for production of higher amounts of dirhamnolipids compared to the DBT-sulfone and inorganic sulfate cultures. The gene expression results were in good agreement with the biosurfactants production yields and surface tension measurements. The sulfur source mediates a fine-tuned mechanism of transcriptional regulation of biosurfactants production genes. Our findings can have an impact on industrial production of biosurfactants and other biotechnological processes like

  6. LrABCF1, a GCN-type ATP-binding cassette transporter from Lilium regale, is involved in defense responses against viral and fungal pathogens

    Science.gov (United States)

    ATP-binding cassette (ABC) transporters are essential for membrane translocation in diverse biological processes, such as plant development and defense response. Here, a general control non-derepressible (GCN)-type ABC transporter gene, designated LrABCF1, was identified from Cucumber mosaic virus (...

  7. The cystic-fibrosis-associated ΔF508 mutation confers post-transcriptional destabilization on the C. elegans ABC transporter PGP-3

    Directory of Open Access Journals (Sweden)

    Liping He

    2012-11-01

    Membrane proteins make up ∼30% of the proteome. During the early stages of maturation, this class of proteins can experience localized misfolding in distinct cellular compartments, such as the cytoplasm, endoplasmic reticulum (ER lumen and ER membrane. ER quality control (ERQC mechanisms monitor folding and determine whether a membrane protein is appropriately folded or is misfolded and warrants degradation. ERQC plays crucial roles in human diseases, such as cystic fibrosis, in which deletion of a single amino acid (F508 results in the misfolding and degradation of the cystic fibrosis transmembrane conductance regulator (CFTR Cl– channel. We introduced the ΔF508 mutation into Caenorhabditis elegans PGP-3, a 12-transmembrane ABC transporter with 15% identity to CFTR. When expressed in intestinal epithelial cells, PGP-3wt was stable and efficiently trafficked to the apical plasma membrane through a COPII-dependent mechanism. However, PGP-3ΔF508 was post-transcriptionally destabilized, resulting in reduced total and apical membrane protein levels. Genetic or physiological activation of the osmotic stress response pathway, which causes accumulation of the chemical chaperone glycerol, stabilized PGP-3ΔF508. Efficient degradation of PGP-3ΔF508 required the function of several C. elegans ER-associated degradation (ERAD homologs, suggesting that destabilization occurs through an ERAD-type mechanism. Our studies show that the ΔF508 mutation causes post-transcriptional destabilization and degradation of PGP-3 in C. elegans epithelial cells. This model, combined with the power of C. elegans genetics, provides a new opportunity to genetically dissect metazoan ERQC.

  8. The ABCs of flower development: mutational analysis of AP1/FUL-like genes in rice provides evidence for a homeotic (A)-function in grasses.

    Science.gov (United States)

    Wu, Feng; Shi, Xiaowei; Lin, Xuelei; Liu, Yuan; Chong, Kang; Theißen, Günter; Meng, Zheng

    2017-01-01

    The well-known ABC model describes the combinatorial interaction of homeotic genes in specifying floral organ identities. While the B- and C-functions are highly conserved throughout flowering plants and even in gymnosperms, the A-function, which specifies the identity of perianth organs (sepals and petals in eudicots), remains controversial. One reason for this is that in most plants that have been investigated thus far, with Arabidopsis being a remarkable exception, one does not find recessive mutants in which the identity of both types of perianth organs is affected. Here we report a comprehensive mutational analysis of all four members of the AP1/FUL-like subfamily of MADS-box genes in rice (Oryza sativa). We demonstrate that OsMADS14 and OsMADS15, in addition to their function of specifying meristem identity, are also required to specify palea and lodicule identities. Because these two grass-specific organs are very likely homologous to sepals and petals of eudicots, respectively, we conclude that there is a floral homeotic (A)-function in rice as defined previously. Together with other recent findings, our data suggest that AP1/FUL-like genes were independently recruited to fulfil the (A)-function in grasses and some eudicots, even though other scenarios cannot be excluded and are discussed.

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

    Science.gov (United States)

    2010-08-13

    ... Surface Transportation Board 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... operation of this trackage in FD 35356, ABC & D Recycling, Inc.--Lease and Operation Exemption--a Line...

  10. Formation of the productive ATP-Mg2+-bound dimer of GlcV, an ABC-ATPase from Sulfolobus solfataricus

    NARCIS (Netherlands)

    Verdon, G; Albers, SV; van Oosterwijk, N; Dijkstra, BW; Driessen, AJM; Thunnissen, AMWH; Dijkstra, Bauke W.

    2003-01-01

    The ABC-ATPase GlcV from Sulfolobus solfataricus energizes an ABC transporter mediating glucose uptake. In ABC transporters, two ABC-ATPases are believed to form a head-to-tail dimer, with both monomers contributing conserved residues to each of the two productive active sites. In contrast, isolated

  11. The ABC of cholesterol transport

    NARCIS (Netherlands)

    Plösch, Torsten

    2004-01-01

    Cholesterol fulfills an indispensable role in mammalian physiology. It is an important constituent of all cell membranes. Furthermore, it is the precursor of steroid hormones, which regulate a variety of physiological functions, and of bile salts, which are necessary for the generation of bile flow

  12. MADS-box gene evolution - structure and transcription patterns

    DEFF Research Database (Denmark)

    Johansen, Bo; Pedersen, Louise Buchholt; Skipper, Martin;

    2002-01-01

    Mads-box genes, ABC model, Evolution, Phylogeny, Transcription patterns, Gene structure, Conserved motifs......Mads-box genes, ABC model, Evolution, Phylogeny, Transcription patterns, Gene structure, Conserved motifs...

  13. Transport in technicolor: mapping ATP-binding cassette transporters in sea urchin embryos.

    Science.gov (United States)

    Gökirmak, Tufan; Shipp, Lauren E; Campanale, Joseph P; Nicklisch, Sascha C T; Hamdoun, Amro

    2014-09-01

    One quarter of eukaryotic genes encode membrane proteins. These include nearly 1,000 transporters that translocate nutrients, signaling molecules, and xenobiotics across membranes. While it is well appreciated that membrane transport is critical for development, the specific roles of many transporters have remained cryptic, in part because of their abundance and the diversity of their substrates. Multidrug resistance ATP-binding cassette (ABC) efflux transporters are one example of cryptic membrane proteins. Although most organisms utilize these ABC transporters during embryonic development, many of these transporters have broad substrate specificity, and their developmental functions remain incompletely understood. Here, we review advances in our understanding of ABC transporters in sea urchin embryos, and methods developed to spatially and temporally map these proteins. These studies reveal that multifunctional transporters are required for signaling, homeostasis, and protection of the embryo, and shed light on how they are integrated into ancestral developmental pathways recapitulated in disease.

  14. 巴西橡胶树胶乳表达ABC转运蛋白HbGCN1的克隆与表达研究%loning and Expression Analysis of HbGCN1 Encoding an ABC Transporter in the Latex of Rubber Tree (Hevea brasiliensis Müll.Arg.)

    Institute of Scientific and Technical Information of China (English)

    聂智毅; 黎瑜; 李波; 夏可灿; 段翠芳

    2012-01-01

    橡胶生物合成是一种典型的植物类异戊二烯次生代谢,它是影响橡胶产量的首要因素.ABC转运蛋白(ATP Binding Cassette transporter,ABC transporter)是一类与植物次生代谢密切相关的蛋白大家族.筛选已构建的茉莉酸诱导橡胶树胶乳消减文库,并克隆了1个GCN(general control non-repressible)亚族ABC转运蛋白基因EST,通过RACE技术获得其全长cDNA序列,命名为HbGCN1.该基因开放阅读框共1 815 bp,编码605个氨基酸残基.表达分析表明:HbGCN1主要在橡胶树树皮及胶乳中表达,且在乙烯、茉莉酸或伤害诱导下上调表达,推测其可能与橡胶生物合成相关.原核表达该基因,为进一步的研究奠定基础.%Rubber biosynthesis, a typical isoprenoid biosynthesis pathway, has been the key important factor limiting rubber latex yield. ABC (ATP-BindingCassette)transporters are a large protein family which is closely involved in the plant secondary metabolites. Through screening a jasmonic -induced latex SSH cDNA library combined with RACE, one EST encoding ABC transporter of GCN subgroup and its full-length cDNA, named as HbGCNl were obtained. HbGCNl contains a ORF with 1 815 bp and encodes a polypeptide of 605 amino acids. The expression patterns show that HbGCNl is primarily expressed in latex or bark. Under ethylene, jasmonic acid and wounding induction, its expression is up-regulated. Based on the above analysis, it is speculated that HbGCNl may be closely correlated to the rubber biosynthesis. Moreover, the prokaryotie expression of the gene lay the foundation for further research.

  15. AcrB, AcrD, and MdtABC multidrug efflux systems are involved in enterobactin export in Escherichia coli.

    Science.gov (United States)

    Horiyama, Tsukasa; Nishino, Kunihiko

    2014-01-01

    Escherichia coli produces the iron-chelating compound enterobactin to enable growth under iron-limiting conditions. After biosynthesis, enterobactin is released from the cell. However, the enterobactin export system is not fully understood. Previous studies have suggested that the outer membrane channel TolC is involved in enterobactin export. There are several multidrug efflux transporters belonging to resistance-nodulation-cell division (RND) family that require interaction with TolC to function. Therefore, several RND transporters may be responsible for enterobactin export. In this study, we investigated whether RND transporters are involved in enterobactin export using deletion mutants of multidrug transporters in E. coli. Single deletions of acrB, acrD, mdtABC, acrEF, or mdtEF did not affect the ability of E. coli to excrete enterobactin, whereas deletion of tolC did affect enterobactin export. We found that multiple deletion of acrB, acrD, and mdtABC resulted in a significant decrease in enterobactin export and that plasmids carrying the acrAB, acrD, or mdtABC genes restored the decrease in enterobactin export exhibited by the ΔacrB acrD mdtABC mutant. These results indicate that AcrB, AcrD, and MdtABC are required for the secretion of enterobactin.

  16. The role of the atypical kinases ABC1K7 and ABC1K8 in abscisic acid responses

    Directory of Open Access Journals (Sweden)

    Anna eManara

    2016-03-01

    Full Text Available The ABC1K family of atypical kinases (activity of bc1 complex kinase is represented in bacteria, archaea and eukaryotes. In plants they regulate diverse physiological processes in the chloroplasts and mitochondria, but their precise functions are poorly defined. ABC1K7 and ABC1K8 are probably involved in oxidative stress responses, isoprenyl lipid synthesis and distribution of iron within chloroplasts. Because reactive oxygen species take part in abscisic acid (ABA-mediated processes, we investigated the functions of ABC1K7 and ABC1K8 during germination, stomatal movement and leaf senescence. Both genes were upregulated by ABA treatment and some ABA-responsive physiological processes were affected in abc1k7 and abc1k8 mutants. Germination was more severely affected by ABA, osmotic stress and salt stress in the single and double mutants; the stomatal aperture was smaller in the mutants under standard growth conditions and was not further reduced by exogenous ABA application; ABA-induced senescence symptoms were more severe in the leaves of the single and double mutants compared to wild type leaves. Taken together, our results suggest that ABC1K7 and ABC1K8 might be involved in the cross-talk between ABA and ROS signaling.

  17. Genome-wide identification and evolution of ATP-binding cassette transporters in the ciliate Tetrahymena thermophila: A case of functional divergence in a multigene family

    Directory of Open Access Journals (Sweden)

    Yuan Dongxia

    2010-10-01

    Full Text Available Abstract Background In eukaryotes, ABC transporters that utilize the energy of ATP hydrolysis to expel cellular substrates into the environment are responsible for most of the efflux from cells. Many members of the superfamily of ABC transporters have been linked with resistance to multiple drugs or toxins. Owing to their medical and toxicological importance, members of the ABC superfamily have been studied in several model organisms and warrant examination in newly sequenced genomes. Results A total of 165 ABC transporter genes, constituting a highly expanded superfamily relative to its size in other eukaryotes, were identified in the macronuclear genome of the ciliate Tetrahymena thermophila. Based on ortholog comparisons, phylogenetic topologies and intron characterizations, each highly expanded ABC transporter family of T. thermophila was classified into several distinct groups, and hypotheses about their evolutionary relationships are presented. A comprehensive microarray analysis revealed divergent expression patterns among the members of the ABC transporter superfamily during different states of physiology and development. Many of the relatively recently formed duplicate pairs within individual ABC transporter families exhibit significantly different expression patterns. Further analysis showed that multiple mechanisms have led to functional divergence that is responsible for the preservation of duplicated genes. Conclusion Gene duplications have resulted in an extensive expansion of the superfamily of ABC transporters in the Tetrahymena genome, making it the largest example of its kind reported in any organism to date. Multiple independent duplications and subsequent divergence contributed to the formation of different families of ABC transporter genes. Many of the members within a gene family exhibit different expression patterns. The combination of gene duplication followed by both sequence divergence and acquisition of new patterns of

  18. Rapportering med ABC modellen

    DEFF Research Database (Denmark)

    Wiese, Lars Ole

    2006-01-01

    I denne artikel diskuteres Activity Based Costing (ABC) som rapporterings-teknik for kunde profitabilitet. Der argumenteres for, at indtægtserhvervel-sen inkl. dens direkte omkostningsforbrug bør adskilles fra omkostnings-beskrivelsen til produktfremstilling. Dvs. der gennemføres en aktivitetsba...

  19. ABC's of Being Smart

    Science.gov (United States)

    Foster, Joanne

    2011-01-01

    Determining what giftedness is all about means focusing on many aspects of the individual. In this paper, the author focuses on letter D of the ABC's of being smart. She starts with specifics about giftedness (details), and then moves on to some ways of thinking (dispositions).

  20. Dual Zinc Transporter Systems in Vibrio cholerae Promote Competitive Advantages over Gut Microbiome.

    Science.gov (United States)

    Sheng, Ying; Fan, Fenxia; Jensen, Owen; Zhong, Zengtao; Kan, Biao; Wang, Hui; Zhu, Jun

    2015-10-01

    Zinc is an essential trace metal required for numerous cellular processes in all forms of life. In order to maintain zinc homeostasis, bacteria have developed several transport systems to regulate its uptake. In this study, we investigated zinc transport systems in the enteric pathogen Vibrio cholerae, the causative agent of cholera. Bioinformatic analysis predicts that two gene clusters, VC2081 to VC2083 (annotated as zinc utilization genes znuABC) and VC2551 to VC2555 (annotated as zinc-regulated genes zrgABCDE), are regulated by the putative zinc uptake regulator Zur. Using promoter reporter and biochemical assays, we confirmed that Zur represses znuABC and zrgABCDE promoters in a Zn(2+)-dependent manner. Under Zn(2+)-limiting conditions, we found that mutations in either the znuABC or zrgABCDE gene cluster affect bacterial growth, with znuABC mutants displaying a more severe growth defect, suggesting that both ZnuABC and ZrgABCDE are involved in Zn(2+) uptake and that ZnuABC plays the predominant role. Furthermore, we reveal that ZnuABC and ZrgABCDE are important for V. cholerae colonization in both infant and adult mouse models, particularly in the presence of other intestinal microbiota. Collectively, our studies indicate that these two zinc transporter systems play vital roles in maintaining zinc homeostasis during V. cholerae growth and pathogenesis.

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

    Directory of Open Access Journals (Sweden)

    Omar Torres-Quesada

    Full Text Available 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.

  2. A novel mode of ferric ion coordination by the periplasmic ferric ion-binding subunit FbpA of an ABC-type iron transporter from Thermus thermophilus HB8.

    Science.gov (United States)

    Wang, Shipeng; Ogata, Misaki; Horita, Shoichiro; Ohtsuka, Jun; Nagata, Koji; Tanokura, Masaru

    2014-01-01

    Crystal structures of FbpA, the periplasmic ferric ion-binding protein of an iron-uptake ABC transporter, from Thermus thermophilus HB8 (TtFbpA) have been solved in apo and ferric ion-bound forms at 1.8 and 1.7 Å resolution, respectively. The latter crystal structure shows that the bound ferric ion forms a novel six-coordinated complex with three tyrosine side chains, two bicarbonates and a water molecule in the metal-binding site. The results of gel-filtration chromatography and dynamic light scattering show that TtFbpA exists as a monomer in solution regardless of ferric ion binding and that TtFbpA adopts a more compact conformation in the ferric ion-bound state than in the apo state in solution.

  3. Xenobiotic transporters: ascribing function from gene knockout and mutation studies.

    Science.gov (United States)

    Klaassen, Curtis D; Lu, Hong

    2008-02-01

    Transporter-mediated absorption, secretion, and reabsorption of chemicals are increasingly recognized as important determinants in the biological activities of many xenobiotics. In recent years, the rapid progress in generating and characterizing mice with targeted deletion of transporters has greatly increased our knowledge of the functions of transporters in the pharmacokinetics/toxicokinetics of xenobiotics. In this introduction, we focus on functions of transporters learned from experiments on knockout mice as well as humans and rodents with natural mutations of these transporters. We limit our discussion to transporters that either directly transport xenobiotics or are important in biliary excretion or cellular defenses, namely multidrug resistance, multidrug resistance-associated proteins, breast cancer resistance protein, organic anion transporting polypeptides, organic anion transporters, organic cation transporters, nucleoside transporters, peptide transporters, bile acid transporters, cholesterol transporters, and phospholipid transporters, as well as metal transporters. Efflux transporters in intestine, liver, kidney, brain, testes, and placenta can efflux xenobiotics out of cells and serve as barriers against the entrance of xenobiotics into cells, whereas many xenobiotics enter the biological system via uptake transporters. The functional importance of a given transporter in each tissue depends on its substrate specificity, expression level, and the presence/absence of other transporters with overlapping substrate preferences. Nevertheless, a transporter may affect a tissue independent of its local expression by altering systemic metabolism. Further studies on the gene regulation and function of transporters, as well as the interrelationship between transporters and phase I/II xenobiotic-metabolizing enzymes, will provide a complete framework for developing novel strategies to protect us from xenobiotic insults.

  4. Flavonoid-mediated inhibition of intestinal ABC transporters may affect the oral bioavailability of drugs, food-borne toxic compounds and bioactive ingredients

    NARCIS (Netherlands)

    Brand, W.; Schutte, M.E.; Bladeren, van P.J.; Rietjens, I.M.C.M.

    2006-01-01

    The transcellular transport of ingested food ingredients across the intestinal epithelial barrier is an important factor determining bioavailability upon oral intake. This transcellular transport of many chemicals, food ingredients, drugs or toxic compounds over the intestinal epithelium can be high

  5. Prevalence of Genes of OXA-23 Carbapenemase and AdeABC Efflux Pump Associated with Multidrug Resistance of Acinetobacter baumannii Isolates in the ICU of a Comprehensive Hospital of Northwestern China

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    Wei Jia

    2015-08-01

    Full Text Available The objective of this study was to explore the molecular epidemiology and the genetic support of clinical multidrug resistant (MDR Acinetobacter baumannii (A. baumannii isolates in an ICU ward of a comprehensive hospital. A total of 102 non-duplicate drug-resistant A. baumannii isolates were identified and 93 (91.1% of them were MDR strains. Molecular analysis demonstrated that carbapenemase genes blaOXA-23 and blaOXA-51 were presented in all 93 MDR isolates (100%, but other carbapenemase genes, including blaOXA-24, blaOXA-58, blaIMP-1, blaIMP-4, blaSIM, and blaVIM genes were completely absent in all isolates. In addition, genes of AdeABC efflux system were detected in 88.2% (90/102 isolates. Interestingly, an addition to efflux pump inhibitor, reserpine could significantly enhance the susceptibility of MDR isolates to moxifloxacin, cefotaxime, and imipenem (p < 0.01. Clonal relationship analysis further grouped these clinical drug-resistant isolates into nine clusters, and the MDR strains were mainly in clusters A, B, C, and D, which include 16, 13, 25, and 15 isolates, respectively. This study demonstrated that clinical isolates carrying carbapenemase-encoding genes blaOXA-23 and AdeABC efflux pump genes are the main prevalent MDR A. baumannii, and the co-expression of oxacillinase and efflux pump proteins are thus considered to be the important reason for the prevalence of this organism in the ICU of this hospital.

  6. Thermodynamics of the ATPase cycle of GlcV, the nucleotide-binding domain of the glucose ABC transporter of Sulfolobus solfataricus

    NARCIS (Netherlands)

    Pretz, Monika G.; Albers, Sonja-Verena; Schuurman-Wolters, Gea; Tampe, Robert; Driessen, Arnold J. M.; van der Does, Chris

    2006-01-01

    ATP-binding cassette transporters drive the transport of substrates across the membrane by the hydrolysis of ATP. They typically have a conserved domain structure with two membrane-spanning domains that form the transport channel and two cytosolic nucleotide-binding domains ( NBDs) that energize the

  7. Molecular Evolutionary Analysis of ABCB5: The Ancestral Gene Is a Full Transporter with Potentially Deleterious Single Nucleotide Polymorphisms

    OpenAIRE

    Karobi Moitra; Mark Scally; Kate McGee; Germaine Lancaster; Bert Gold; Michael Dean

    2011-01-01

    BACKGROUND: ABCB5 is a member of the ABC protein superfamily, which includes the transporters ABCB1, ABCC1 and ABCG2 responsible for causing drug resistance in cancer patients and also several other transporters that have been linked to human disease. The ABCB5 full transporter (ABCB5.ts) is expressed in human testis and its functional significance is presently unknown. Another variant of this transporter, ABCB5 beta possess a "half-transporter-like" structure and is expressed in melanoma ste...

  8. Human transporter database: comprehensive knowledge and discovery tools in the human transporter genes.

    Directory of Open Access Journals (Sweden)

    Adam Y Ye

    Full Text Available Transporters are essential in homeostatic exchange of endogenous and exogenous substances at the systematic, organic, cellular, and subcellular levels. Gene mutations of transporters are often related to pharmacogenetics traits. Recent developments in high throughput technologies on genomics, transcriptomics and proteomics allow in depth studies of transporter genes in normal cellular processes and diverse disease conditions. The flood of high throughput data have resulted in urgent need for an updated knowledgebase with curated, organized, and annotated human transporters in an easily accessible way. Using a pipeline with the combination of automated keywords query, sequence similarity search and manual curation on transporters, we collected 1,555 human non-redundant transporter genes to develop the Human Transporter Database (HTD (http://htd.cbi.pku.edu.cn. Based on the extensive annotations, global properties of the transporter genes were illustrated, such as expression patterns and polymorphisms in relationships with their ligands. We noted that the human transporters were enriched in many fundamental biological processes such as oxidative phosphorylation and cardiac muscle contraction, and significantly associated with Mendelian and complex diseases such as epilepsy and sudden infant death syndrome. Overall, HTD provides a well-organized interface to facilitate research communities to search detailed molecular and genetic information of transporters for development of personalized medicine.

  9. Human transporter database: comprehensive knowledge and discovery tools in the human transporter genes.

    Science.gov (United States)

    Ye, Adam Y; Liu, Qing-Rong; Li, Chuan-Yun; Zhao, Min; Qu, Hong

    2014-01-01

    Transporters are essential in homeostatic exchange of endogenous and exogenous substances at the systematic, organic, cellular, and subcellular levels. Gene mutations of transporters are often related to pharmacogenetics traits. Recent developments in high throughput technologies on genomics, transcriptomics and proteomics allow in depth studies of transporter genes in normal cellular processes and diverse disease conditions. The flood of high throughput data have resulted in urgent need for an updated knowledgebase with curated, organized, and annotated human transporters in an easily accessible way. Using a pipeline with the combination of automated keywords query, sequence similarity search and manual curation on transporters, we collected 1,555 human non-redundant transporter genes to develop the Human Transporter Database (HTD) (http://htd.cbi.pku.edu.cn). Based on the extensive annotations, global properties of the transporter genes were illustrated, such as expression patterns and polymorphisms in relationships with their ligands. We noted that the human transporters were enriched in many fundamental biological processes such as oxidative phosphorylation and cardiac muscle contraction, and significantly associated with Mendelian and complex diseases such as epilepsy and sudden infant death syndrome. Overall, HTD provides a well-organized interface to facilitate research communities to search detailed molecular and genetic information of transporters for development of personalized medicine.

  10. Potency of individual bile acids to regulate bile acid synthesis and transport genes in primary human hepatocyte cultures.

    Science.gov (United States)

    Liu, Jie; Lu, Hong; Lu, Yuan-Fu; Lei, Xiaohong; Cui, Julia Yue; Ellis, Ewa; Strom, Stephen C; Klaassen, Curtis D

    2014-10-01

    Bile acids (BAs) are known to regulate their own homeostasis, but the potency of individual bile acids is not known. This study examined the effects of cholic acid (CA), chenodeoxycholic acid (CDCA), deoxycholic acid (DCA), lithocholic acid (LCA) and ursodeoxycholic acid (UDCA) on expression of BA synthesis and transport genes in human primary hepatocyte cultures. Hepatocytes were treated with the individual BAs at 10, 30, and 100μM for 48 h, and RNA was extracted for real-time PCR analysis. For the classic pathway of BA synthesis, BAs except for UDCA markedly suppressed CYP7A1 (70-95%), the rate-limiting enzyme of bile acid synthesis, but only moderately (35%) down-regulated CYP8B1 at a high concentration of 100μM. BAs had minimal effects on mRNA of two enzymes of the alternative pathway of BA synthesis, namely CYP27A1 and CYP7B1. BAs increased the two major target genes of the farnesoid X receptor (FXR), namely the small heterodimer partner (SHP) by fourfold, and markedly induced fibroblast growth factor 19 (FGF19) over 100-fold. The BA uptake transporter Na(+)-taurocholate co-transporting polypeptide was unaffected, whereas the efflux transporter bile salt export pump was increased 15-fold and OSTα/β were increased 10-100-fold by BAs. The expression of the organic anion transporting polypeptide 1B3 (OATP1B3; sixfold), ATP-binding cassette (ABC) transporter G5 (ABCG5; sixfold), multidrug associated protein-2 (MRP2; twofold), and MRP3 (threefold) were also increased, albeit to lesser degrees. In general, CDCA was the most potent and effective BA in regulating these genes important for BA homeostasis, whereas DCA and CA were intermediate, LCA the least, and UDCA ineffective.

  11. Suppression of c-Myc is involved in multi-walled carbon nanotubes' down-regulation of ATP-binding cassette transporters in human colon adenocarcinoma cells.

    Science.gov (United States)

    Wang, Zhaojing; Xu, Yonghong; Meng, Xiangning; Watari, Fumio; Liu, Hudan; Chen, Xiao

    2015-01-01

    Over-expression of ATP-binding cassette (ABC) transporters, a large family of integral membrane proteins that decrease cellular drug uptake and accumulation by active extrusion, is one of the major causes of cancer multi-drug resistance (MDR) that frequently leads to failure of chemotherapy. Carbon nanotubes (CNTs)-based drug delivery devices hold great promise in enhancing the efficacy of cancer chemotherapy. However, CNTs' effects on the ABC transporters remain under-investigated. In this study, we found that multiwalled carbon nanotubes (MWCNTs) reduced transport activity and expression of ABC transporters including ABCB1/Pgp and ABCC4/MRP4 in human colon adenocarcinoma Caco-2 cells. Proto-oncogene c-Myc, which directly regulates ABC gene expression, was concurrently decreased in MWCNT-treated cells and forced over-expression of c-Myc reversed MWCNTs' inhibitory effects on ABCB1 and ABCC4 expression. MWCNT-cell membrane interaction and cell membrane oxidative damage were observed. However, antioxidants such as vitamin C, β-mecaptoethanol and dimethylthiourea failed to antagonize MWCNTs' down-regulation of ABC transporters. These data suggest that MWCNTs may act on c-Myc, but not through oxidative stress, to down-regulate ABC transporter expression. Our findings thus shed light on CNTs' novel cellular effects that may be utilized to develop CNTs-based drug delivery devices to overcome ABC transporter-mediated cancer chemoresistance.

  12. Staphylococcus aureus and Lipopolysaccharide Modulate Gene Expressions of Drug Transporters in Mouse Mammary Epithelial Cells Correlation to Inflammatory Biomarkers

    Science.gov (United States)

    Yagdiran, Yagmur; Tallkvist, Jonas; Artursson, Karin

    2016-01-01

    Inflammation in the mammary gland (mastitis) is the most common disease in dairy herds worldwide, often caused by the pathogens Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Little is known about the effects of mastitis on drug transporters and the impact on transporter-mediated excretion of drugs into milk. We used murine mammary epithelial HC11 cells, after lactogenic differentiation into a secreting phenotype, and studied gene expressions of ABC- and SLC- transporters after treatment of cells with S. aureus and lipopolysaccharide, an endotoxin secreted by E. coli. The studied transporters were Bcrp, Mdr1, Mrp1, Oatp1a5, Octn1 and Oct1. In addition, Csn2, the gene encoding β-casein, was analyzed. As biomarkers of the inflammatory response, gene expressions of the cytokines Il6 and Tnfα and the chemokine Cxcl2 were determined. Our results show that S. aureus and LPS treatment of cells, at non-cytotoxic concentrations, induced an up-regulation of Mdr1 and of the inflammatory biomarkers, except that Tnfα was not affected by lipopolysaccharide. By simple regression analysis we could demonstrate statistically significant positive correlations between each of the transporters with each of the inflammatory biomarkers in cells treated with S. aureus. The coefficients of determination (R2) were 0.7–0.9 for all but one correlation. After treatment of cells with lipopolysaccharide, statistically significant correlations were only found between Mdr1 and the two parameters Cxcl2 and Il6. The expression of Csn2 was up-regulated in cells treated with S. aureus, indicating that the secretory function of the cells was not impaired. The strong correlation in gene expressions between transporters and inflammatory biomarkers may suggest a co-regulation and that the transporters have a role in the transport of cytokines and chemokines. Our results demonstrate that transporters in mammary cells can be affected by infection, which may have an impact on

  13. ABCs in College English Education

    Institute of Scientific and Technical Information of China (English)

    李利文

    2011-01-01

    As is known to us all, human beings are always brought under control by such many things as the hormone in our body, the mood produced in our brain and the external world, which leads us to a topic of how to create an atmosphere for the undergraduates to fit well in with the college English education. In our teaching management, the ABCs about college English education works as an assistant. Here, ABCs about college English education refer to some fundamental skills with regard to the undergraduates English education. The ABCs, which always encourage students' involvement, would work effectively if teachers understand them well.

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

    OpenAIRE

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

    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 (K m = 1.1 μM) that is ...

  15. Purification, crystallization and preliminary X-ray analysis of the galacto-N-biose-/lacto-N-biose I-binding protein (GL-BP) of the ABC transporter from Bifidobacterium longum JCM1217

    Energy Technology Data Exchange (ETDEWEB)

    Wada, Jun [Graduate School of Biostudies, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan); Suzuki, Ryuichiro; Fushinobu, Shinya [Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657 (Japan); Kitaoka, Motomitsu [National Food Research Institute, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642 (Japan); Wakagi, Takayoshi; Shoun, Hirofumi [Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657 (Japan); Ashida, Hisashi [Graduate School of Biostudies, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan); Kumagai, Hidehiko; Katayama, Takane, E-mail: takane@ishikawa-pu.ac.jp [Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Nonoichi, Ishikawa 921-8836 (Japan); Yamamoto, Kenji [Graduate School of Biostudies, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan)

    2007-09-01

    Preliminary X-ray analysis of the galacto-N-biose-/lacto-N-biose I-binding protein (GL-BP) of the ABC transporter from B. longum is described. A recombinant galacto-N-biose-/lacto-N-biose I-binding protein (GL-BP) from Bifidobacterium longum JCM1217 has been prepared and crystallized by the hanging-drop vapour-diffusion method using 10 mg ml{sup −1} purified enzyme, 0.01 M zinc sulfate, 0.1 M MES buffer pH 5.9–6.4 and 20–22%(v/v) PEG MME 550 in the presence of 5 mM disaccharide ligands. Suitable crystals grew after 10 d incubation at 293 K. The crystals belong to space group C222{sub 1}, with unit-cell parameters a = 106.3, b = 143.6, c = 114.6 Å for the lacto-N-biose I complex and a = 106.4, b = 143.4, c = 115.5 Å for the galacto-N-biose complex, and diffracted to 1.85 and 1.99 Å resolution, respectively.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Iwao Ohtsu

    Full Text Available 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.

  18. The ABCs of Sex Ed.

    Science.gov (United States)

    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)

  19. Politseiniku lustlik ABC / Pekka Erelt

    Index Scriptorium Estoniae

    Erelt, Pekka, 1965-

    1999-01-01

    Politsei on välja andnud 'Politseiniku ABC', mis antakse igale politseinikule. Karikaturist Heiki Ernits on peaaegu igale taskuraamatu leheküljele joonistanud pildikese mundrimeestest kentsakates situatsioonides.

  20. Suppression of c-Myc is involved in multi-walled carbon nanotubes' down-regulation of ATP-binding cassette transporters in human colon adenocarcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhaojing [Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, 430030 Wuhan (China); Xu, Yonghong [Institute of Ophthalmological Research, Department of Ophthalmology, Renmin Hospital of Wuhan University, 430060 Wuhan (China); Meng, Xiangning [School of Materials and Metallurgy, Northeastern University, Shenyang 110819 (China); Watari, Fumio [Department of Biomedical, Dental Materials and Engineering, Graduate School of Dental Medicine, Hokkaido University, Sapporo 060-8586 (Japan); Liu, Hudan, E-mail: hudanliu@hust.edu.cn [Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, 430030 Wuhan (China); Chen, Xiao, E-mail: mornsmile@yahoo.com [Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, 430030 Wuhan (China)

    2015-01-01

    Over-expression of ATP-binding cassette (ABC) transporters, a large family of integral membrane proteins that decrease cellular drug uptake and accumulation by active extrusion, is one of the major causes of cancer multi-drug resistance (MDR) that frequently leads to failure of chemotherapy. Carbon nanotubes (CNTs)-based drug delivery devices hold great promise in enhancing the efficacy of cancer chemotherapy. However, CNTs' effects on the ABC transporters remain under-investigated. In this study, we found that multiwalled carbon nanotubes (MWCNTs) reduced transport activity and expression of ABC transporters including ABCB1/Pgp and ABCC4/MRP4 in human colon adenocarcinoma Caco-2 cells. Proto-oncogene c-Myc, which directly regulates ABC gene expression, was concurrently decreased in MWCNT-treated cells and forced over-expression of c-Myc reversed MWCNTs' inhibitory effects on ABCB1 and ABCC4 expression. MWCNT-cell membrane interaction and cell membrane oxidative damage were observed. However, antioxidants such as vitamin C, β-mecaptoethanol and dimethylthiourea failed to antagonize MWCNTs' down-regulation of ABC transporters. These data suggest that MWCNTs may act on c-Myc, but not through oxidative stress, to down-regulate ABC transporter expression. Our findings thus shed light on CNTs' novel cellular effects that may be utilized to develop CNTs-based drug delivery devices to overcome ABC transporter-mediated cancer chemoresistance.

  1. Not as Simple as ABC

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The Agricultural Bank of China finds it tough as it moves toward marketization The Agricultural Bank of China (ABC) is sailing through rough seas as it weathers the storm of problems uncovered during its current stage of reform.With non-performing assets making up nearly 97 percent of the total of China’ s four large state-owned commercial banks, alarm bells are going off in ABC halls of power.

  2. Expression of Genes for Drug Transporters in the Human Female Genital Tract and Modulatory Effect of Antiretroviral Drugs.

    Directory of Open Access Journals (Sweden)

    Karolin Hijazi

    Full Text Available Anti-retroviral (ARV -based microbicides are one of the strategies pursued to prevent HIV-1 transmission. Delivery of ARV drugs to subepithelial CD4+ T cells at concentrations for protection is likely determined by drug transporters expressed in the cervicovaginal epithelium. To define the role of drug transporters in mucosal disposition of topically applied ARV-based microbicides, these must be tested in epithelial cell line-based biopharmaceutical assays factoring the effect of relevant drug transporters. We have characterised gene expression of influx and efflux drug transporters in a panel of cervicovaginal cell lines and compared this to expression in cervicovaginal tissue. We also investigated the effect of dapivirine, darunavir and tenofovir, currently at advanced stages of microbicides development, on expression of drug transporters in cell lines. Expression of efflux ABC transporters in cervical tissue was best represented in HeLa, Ect1/E6E7 and End1/E6E7 cell lines. Expression of influx OCT and ENT transporters in ectocervix matched expression in Hela while expression of influx SLCO transporters in vagina was best reflected in VK2/E6E7 cell line. Stimulation with darunavir and dapivirine upregulated MRP transporters, including MRP5 involved in transport of tenofovir. Dapivirine also significantly downregulated tenofovir substrate MRP4 in cervical cell lines. Treatment with darunavir and dapivirine showed no significant effect on expression of BCRP, MRP2 and P-glycoprotein implicated in efflux of different ARV drugs. Darunavir strongly induced expression in most cell lines of CNT3 involved in cell uptake of nucleotide/nucleoside analogue reverse transcriptase inhibitors and SLCO drug transporters involved in cell uptake of protease inhibitors. This study provides insight into the suitability of cervicovaginal cell lines for assessment of ARV drugs in transport kinetics studies. The modulatory effect of darunavir and dapivirine on

  3. Transcriptome Analysis to Identify the Putative Biosynthesis and Transport Genes Associated with the Medicinal Components of Achyranthes bidentata Bl.

    Directory of Open Access Journals (Sweden)

    Jinting Li

    2016-12-01

    Full Text Available Achyranthes bidentata is a popular perennial medicine herb used for thousands of years in China to treat various diseases. Although this herb has multiple pharmaceutical purposes in China, no transcriptomic information has been reported for this species. In addition, the understanding of several key pathways and enzymes involved in the biosynthesis of oleanolic acid and ecdysterone, two pharmacologically active classes of metabolites and major chemical constituents of A. bidentata root extracts, is limited. The aim of the present study was to characterize the transcriptome profile of the roots and leaves of A. bidentata to uncover the biosynthetic and transport mechanisms of the active components. In this study, we identified 100,987 transcripts, with an average length of 973.64 base pairs. A total of 31,634 (31.33% unigenes were annotated, and 12,762 unigenes were mapped to 303 pathways according to the Kyoto Encyclopedia of Genes and Genomes (KEGG pathway database. Moreover, we identified a total of 260 oleanolic acid and ecdysterone genes encoding biosynthetic enzymes. Furthermore, the key enzymes involved in the oleanolic acid and ecdysterone synthesis pathways were analyzed using quantitative real-time polymerase chain reaction (qRT-PCR, revealing that the roots expressed these enzymes to a greater extent than the leaves. In addition, we identified 85 ATP-binding cassette (ABC transporters, some of which might be involved in the translocation of secondary metabolites.

  4. Cadmium-inducible expression of the ABC-type transporter AtABCC3 increases phytochelatin-mediated cadmium tolerance in Arabidopsis.

    Science.gov (United States)

    Brunetti, Patrizia; Zanella, Letizia; De Paolis, Angelo; Di Litta, Davide; Cecchetti, Valentina; Falasca, Giuseppina; Barbieri, Maurizio; Altamura, Maria Maddalena; Costantino, Paolo; Cardarelli, Maura

    2015-07-01

    The heavy metal cadmium (Cd) is a widespread environmental contaminant with harmful effects on living cells. In plants, phytochelatin (PC)-dependent Cd detoxification requires that PC-Cd complexes are transported into vacuoles. Here, it is shown that Arabidopsis thaliana seedlings defective in the ABCC transporter AtABCC3 (abcc3) have an increased sensitivity to different Cd concentrations, and that seedlings overexpressing AtABCC3 (AtABCC3ox) have an increased Cd tolerance. The cellular distribution of Cd was analysed in protoplasts from abcc3 mutants and AtABCC3 overexpressors grown in the presence of Cd, by means of the Cd-specific fluorochromes 5-nitrobenzothiazole coumarin (BTC-5N) and Leadmium™ Green AM dye. This analysis revealed that Cd is mostly localized in the cytosol of abcc3 mutant protoplasts whereas there is an increase in vacuolar Cd in protoplasts from AtABCC3ox plants. Overexpression of AtABCC3 in cad1-3 mutant seedlings defective in PC production and in plants treated with l-buthionine sulphoximine (BSO), an inhibitor of PC biosynthesis, had no effect on Cd tolerance, suggesting that AtABCC3 acts via PCs. In addition, overexpression of AtABCC3 in atabcc1 atabcc2 mutant seedlings defective in the Cd transporters AtABCC1 and AtABCC2 complements the Cd sensitivity of double mutants, but not in the presence of BSO. Accordingly, the level of AtABCC3 transcript in wild type seedlings was lower than that of AtABCC1 and AtABCC2 in the absence of Cd but higher after Cd exposure, and even higher in atabcc1 atabcc2 mutants. The results point to AtABCC3 as a transporter of PC-Cd complexes, and suggest that its activity is regulated by Cd and is co-ordinated with the activity of AtABCC1/AtABCC2.

  5. Transport of magnesium by a bacterial Nramp-related gene.

    Directory of Open Access Journals (Sweden)

    Jung-Ho Shin

    2014-06-01

    Full Text Available Magnesium is an essential divalent metal that serves many cellular functions. While most divalent cations are maintained at relatively low intracellular concentrations, magnesium is maintained at a higher level (∼0.5-2.0 mM. Three families of transport proteins were previously identified for magnesium import: CorA, MgtE, and MgtA/MgtB P-type ATPases. In the current study, we find that expression of a bacterial protein unrelated to these transporters can fully restore growth to a bacterial mutant that lacks known magnesium transporters, suggesting it is a new importer for magnesium. We demonstrate that this transport activity is likely to be specific rather than resulting from substrate promiscuity because the proteins are incapable of manganese import. This magnesium transport protein is distantly related to the Nramp family of proteins, which have been shown to transport divalent cations but have never been shown to recognize magnesium. We also find gene expression of the new magnesium transporter to be controlled by a magnesium-sensing riboswitch. Importantly, we find additional examples of riboswitch-regulated homologues, suggesting that they are a frequent occurrence in bacteria. Therefore, our aggregate data discover a new and perhaps broadly important path for magnesium import and highlight how identification of riboswitch RNAs can help shed light on new, and sometimes unexpected, functions of their downstream genes.

  6. Prevalence of Genes of OXA-23 Carbapenemase and AdeABC Efflux Pump Associated with Multidrug Resistance of Acinetobacter baumannii Isolates in the ICU of a Comprehensive Hospital of Northwestern China.

    Science.gov (United States)

    Jia, Wei; Li, Caiyun; Zhang, Haiyun; Li, Gang; Liu, Xiaoming; Wei, Jun

    2015-08-21

    The objective of this study was to explore the molecular epidemiology and the genetic support of clinical multidrug resistant (MDR) Acinetobacter baumannii (A. baumannii) isolates in an ICU ward of a comprehensive hospital. A total of 102 non-duplicate drug-resistant A. baumannii isolates were identified and 93 (91.1%) of them were MDR strains. Molecular analysis demonstrated that carbapenemase genes blaOXA-23 and blaOXA-51 were presented in all 93 MDR isolates (100%), but other carbapenemase genes, including blaOXA-24, blaOXA-58, blaIMP-1, blaIMP-4, blaSIM, and blaVIM genes were completely absent in all isolates. In addition, genes of AdeABC efflux system were detected in 88.2% (90/102) isolates. Interestingly, an addition to efflux pump inhibitor, reserpine could significantly enhance the susceptibility of MDR isolates to moxifloxacin, cefotaxime, and imipenem (p baumannii, and the co-expression of oxacillinase and efflux pump proteins are thus considered to be the important reason for the prevalence of this organism in the ICU of this hospital.

  7. Crystal structure of the antigen-binding fragment of a monoclonal antibody specific for the multidrug-resistance-linked ABC transporter human P-glycoprotein

    Energy Technology Data Exchange (ETDEWEB)

    Esser, Lothar; Shukla, Suneet; Zhou, Fei; Ambudkar, Suresh V.; Xia, Di

    2016-07-27

    P-glycoprotein (P-gp) is a polyspecific ATP-dependent transporter linked to multidrug resistance in cancers that plays important roles in the pharmacokinetics of a large number of drugs. The drug-resistance phenotype of P-gp can be modulated by the monoclonal antibody UIC2, which specifically recognizes human P-gp in a conformation-dependent manner. Here, the purification, sequence determination and high-resolution structure of the Fab fragment of UIC2 (UIC2/Fab) are reported. Purified UIC2/Fab binds human P-gp with a 1:1 stoichiometry. Crystals of UIC2/Fab are triclinic (space groupP1), with unit-cell parametersa= 40.67,b= 44.91,c= 58.09 Å, α = 97.62, β = 99.10, γ = 94.09°, and diffracted X-rays to 1.6 Å resolution. The structure was determined by molecular replacement and refined to 1.65 Å resolution. The asymmetric unit contains one molecule of UIC2/Fab, which exhibits a positively charged antigen-binding surface, suggesting that it might recognize an oppositely charged extracellular epitope of P-gp.

  8. RECOMBINANT CO-EXPRESSION OF THE ECTOINE BIOSYNTHESIS GENE CLUSTER ectABC IN HALOMONAS FROM QINGHAI LAKE%青海湖盐单胞菌Ectoine合成基因簇ectABC的重组共表达

    Institute of Scientific and Technical Information of China (English)

    朱德锐; 韩睿; 沈国平; 龙启福; 李丹丹; 刘建; 刘德立

    2015-01-01

    Halomonas is capable of synthesizing organic compatible solutes ectoine in response to high osmotic pressure. To reveal the possibility of heterologous co-expression of ectoine biosynthesis genes, intracellular ectoine in Halomonas sp. QHL1 strain was determined by HPLC under different salt gradients. The entire ectABC gene cluster for ectoine synthesis was cloned using genome walking and expressed in the heterologous recombinant E. coli BL21. The results showed that the concentration of ectoine accumulated in the cells had a positive correlation with the extracellular Na+concentration and reached a maximum value (167.1 mg/g cell dry weight) at 1.0 mol/L Na+, and high concentration of Na+ strongly inhibited the bacteria growth. The entire ectABC gene cluster in QHL1 strain was 3580 bp, containing structural gene ectA (579 bp), ectB (1269 bp) and ectC (390 bp). Based on bioinformatics prediction analysis, two puta-tive promoters (δ70 andδ38-controlled promoter) and several conserved motifs with unknown function were identified in the upstream of ect-operon. The recombinant plasmid pET-28a (+)-ectABC was successfully constructed, and the results of heterologous expression indicated that these three genes could be simultaneously translated to protein EctA (27.2 kD), EctB (52.5 kD) and EctC (20.8 kD). These results contribute further improvements in ectoine high yield and hypohaline biotechnological process optimization, and also provided a framework for future genetic manipulation of systems metabolic engineering.%盐单胞菌属(Halomonas)通过胞内积聚有机相容溶质(Compatible solutes)来抵抗胞外的高盐渗透压。为了探究相容溶质 Ectoine 合成代谢相关基因的结构特征和异源共表达的可能性,以青海湖盐单胞菌Halomonas sp. QHL1为材料,通过高效液相色谱(HPLC)分析不同盐梯度下QHL1胞内Ectoine的积聚量,并借助于染色体步移技术(Genome walking)捕获QHL1菌株的Ectoine生物合成基因簇ectABC

  9. Candidate genes for performance in horses, including monocarboxylate transporters

    Directory of Open Access Journals (Sweden)

    Inaê Cristina Regatieri

    Full Text Available ABSTRACT: Some horse breeds are highly selected for athletic activities. The athletic potential of each animal can be measured by its performance in sports. High athletic performance depends on the animal capacity to produce energy through aerobic and anaerobic metabolic pathways, among other factors. Transmembrane proteins called monocarboxylate transporters, mainly the isoform 1 (MCT1 and its ancillary protein CD147, can help the organism to adapt to physiological stress caused by physical exercise, transporting lactate and H+ ions. Horse breeds are selected for different purposes so we might expect differences in the amount of those proteins and in the genotypic frequencies for genes that play a significant role in the performance of the animals. The study of MCT1 and CD147 gene polymorphisms, which can affect the formation of the proteins and transport of lactate and H+, can provide enough information to be used for selection of athletic horses increasingly resistant to intense exercise. Two other candidate genes, the PDK4 and DMRT3, have been associated with athletic potential and indicated as possible markers for performance in horses. The oxidation of fatty acids is highly effective in generating ATP and is controlled by the expression of PDK4 (pyruvate dehydrogenase kinase, isozyme 4 in skeletal muscle during and after exercise. The doublesex and mab-3 related transcription factor 3 (DMRT3 gene encodes an important transcription factor in the setting of spinal cord circuits controlling movement in vertebrates and may be associated with gait performance in horses. This review describes how the monocarboxylate transporters work during physical exercise in athletic horses and the influence of polymorphisms in candidate genes for athletic performance in horses.

  10. Association between serotonin transporter gene polymorphism and recurrent aphthous stomatitis

    Science.gov (United States)

    Manchanda, Aastha; Iyengar, Asha R.; Patil, Seema

    2016-01-01

    Background: Anxiety-related traits have been attributed to sequence variability in the genes coding for serotonin transmission in  the brain. Two alleles, termed long (L) and short (S) differing by 44 base pairs, are found in a polymorphism identified in the promoter region of serotonin transporter gene. The presence of the short allele  and SS and LS genotypes is found to be associated with the reduced expression of this gene decreasing the uptake of serotonin in the brain leading to various anxiety-related traits. Recurrent aphthous stomatitis (RAS) is an oral mucosal disease with varied etiology including the presence of stress, anxiety, and genetic influences. The present study aimed to determine this serotonin transporter gene polymorphism in patients with RAS and compare it with normal individuals. Materials and Methods: This study included 20 subjects with various forms of RAS and 20 normal healthy age- and gender-matched individuals. Desquamated oral mucosal cells were collected for DNA extraction and subjected to polymerase chain reaction for studying insertion/deletion in the 5-HTT gene-linked polymorphic region. Cross tabulations followed by Chi-square tests were performed to compare the significance of findings, P < 0.05 was considered statistically significant. Results: The LS genotype was the most common genotype found in the subjects with aphthous stomatitis (60%) and controls (40%). The total percentage of LS and SS genotypes and the frequency of S allele were found to be higher in the subjects with aphthous stomatitis as compared to the control group although a statistically significant correlation could not be established, P = 0.144 and 0.371, respectively. Conclusion: Within the limitations of this study, occurrence of RAS was not found to be associated with polymorphic promoter region in serotonin transporter gene. PMID:27274339

  11. The ABCs of particle physics

    CERN Document Server

    Biron, Lauren

    2016-01-01

    For lovers of rhymes and anthropomorphic Higgs bosons, Symmetry presents its first published board book, The ABCs of Particle Physics. Use it as an illustrated guide to basic particle- and astrophysics terms, or read it to your infant at bedtime, if you don’t mind their first word being “quark.”

  12. The ABCs of Student Engagement

    Science.gov (United States)

    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…

  13. Wireless technology for ABC Assessment

    DEFF Research Database (Denmark)

    Kristensen, Margit; Kyng, Morten; Christensen, Erika Frischknecht;

      In medical emergency service (EMS) the ABC status (Airway-Breathing-Circulation) of victims is essential in the decision making process regarding prioritizing and treatment. Today's use of information technology does, however, not inform directly about "A" and "B". The parameters are evaluated ...

  14. An association study between the norepinephrine transporter gene and depression

    DEFF Research Database (Denmark)

    Buttenschøn, Henriette N; Jacobsen, Iben S; Grynderup, Matias B;

    2013-01-01

    A2 for solute carrier 6 family member 2). The gene is responsible for the reuptake of norepinephrine and dopamine into presynaptic nerve terminals and the norepinephrine system appears to play an important role in depression. We therefore analyzed genetic variants within SLC6A2 for association......A potential approach for identification of candidate genes for depression is characterization of chromosomal rearrangements. Through analysis of a chromosome translocation in an individual with recurrent depression, we identified a potential candidate gene: the norepinephrine transporter (NET; SLC6...... with depression in 408 affected and 559 control individuals from Denmark. After quality control of the genotypes, 31 of 45 single nucleotide polymorphisms (SNPs) were left for analyses. One SNP showed a nominal association with depression but did not survive correction for multiple testing. The results from our...

  15. The norepinephrine transporter gene is a candidate gene for panic disorder

    DEFF Research Database (Denmark)

    Buttenschøn, Henriette Nørmølle; Kristensen, A S; Buch, H N

    2011-01-01

    of PD. The SLC6A2 gene is located on chromosome 16q12.2 and encodes the norepinephrine transporter (NET), responsible for the reuptake of norepinephrine into presynaptic nerve terminals. The aim of the present study was to analyze genetic variants located within the NET gene for association with PD....... The case-control sample consisted of 449 patients with PD and 279 ethnically matched controls. All cases fulfilled the ICD-10 diagnostic criteria for PD. Genotyping was performed using the Sequenom platform (Sequenom, Inc, San Diego, USA). To test for allelic and haplotypic association, the PLINK software...... was used, and COMBASSOC was applied to test for gene-wise association. After quality control 29 single nucleotide polymorphisms (SNPs) spanning the gene-region were successfully analyzed. Seven SNPs located within the 5' end of the gene were significantly associated with PD. Furthermore, the NET gene...

  16. 75 FR 11991 - ABC & D Recycling, Inc.-Lease and Operation Exemption-a Line of Railroad in Ware, MA

    Science.gov (United States)

    2010-03-12

    ... Surface Transportation Board ABC & D Recycling, Inc.--Lease and Operation Exemption--a Line of Railroad in... under 49 CFR 1150.31 to lease from O'Riley Family Trust (O'Riley), and to operate 773 feet of rail line... lease and operate the railroad trackage owned by O'Riley. ABC & D states that it has and intends...

  17. Parental vitamin deficiency affects the embryonic gene expression of immune-, lipid transport- and apolipoprotein genes

    Science.gov (United States)

    Skjærven, Kaja H.; Jakt, Lars Martin; Dahl, John Arne; Espe, Marit; Aanes, Håvard; Hamre, Kristin; Fernandes, Jorge M. O.

    2016-10-01

    World Health Organization is concerned for parental vitamin deficiency and its effect on offspring health. This study examines the effect of a marginally dietary-induced parental one carbon (1-C) micronutrient deficiency on embryonic gene expression using zebrafish. Metabolic profiling revealed a reduced 1-C cycle efficiency in F0 generation. Parental deficiency reduced the fecundity and a total of 364 genes were differentially expressed in the F1 embryos. The upregulated genes (53%) in the deficient group were enriched in biological processes such as immune response and blood coagulation. Several genes encoding enzymes essential for the 1-C cycle and for lipid transport (especially apolipoproteins) were aberrantly expressed. We show that a parental diet deficient in micronutrients disturbs the expression in descendant embryos of genes associated with overall health, and result in inherited aberrations in the 1-C cycle and lipid metabolism. This emphasises the importance of parental micronutrient status for the health of the offspring.

  18. The serotonin transporter gene and startle response during nicotine deprivation.

    Science.gov (United States)

    Minnix, Jennifer A; Robinson, Jason D; Lam, Cho Y; Carter, Brian L; Foreman, Jennifer E; Vandenbergh, David J; Tomlinson, Gail E; Wetter, David W; Cinciripini, Paul M

    2011-01-01

    Affective startle probe methodology was used to examine the effects of nicotine administration and deprivation on emotional processes among individuals carrying at least one s allele versus those with the l/l genotype of the 5-Hydroxytryptamine (Serotonin) Transporter Linked Polymorphic Region, 5-HTTLPR in the promoter region of the serotonin transporter gene [solute ligand carrier family 6 member A4 (SLC6A4) or SERT]. Smokers (n=84) completed four laboratory sessions crossing deprivation (12-h deprived vs. non-deprived) with nicotine spray (nicotine vs. placebo). Participants viewed affective pictures (positive, negative, neutral) while acoustic startle probes were administered. We found that smokers with the l/l genotype showed significantly greater suppression of the startle response when provided with nicotine vs. placebo than those with the s/s or s/l genotypes. The results suggest that l/l smokers, who may have higher levels of the serotonin transporter and more rapid synaptic serotonin clearance, experience substantial reduction in activation of the defensive system when exposed to nicotine.

  19. Extensive intra-kingdom horizontal gene transfer converging on a fungal fructose transporter gene.

    Directory of Open Access Journals (Sweden)

    Marco A Coelho

    2013-06-01

    Full Text Available Comparative genomics revealed in the last decade a scenario of rampant horizontal gene transfer (HGT among prokaryotes, but for fungi a clearly dominant pattern of vertical inheritance still stands, punctuated however by an increasing number of exceptions. In the present work, we studied the phylogenetic distribution and pattern of inheritance of a fungal gene encoding a fructose transporter (FSY1 with unique substrate selectivity. 109 FSY1 homologues were identified in two sub-phyla of the Ascomycota, in a survey that included 241 available fungal genomes. At least 10 independent inter-species instances of horizontal gene transfer (HGT involving FSY1 were identified, supported by strong phylogenetic evidence and synteny analyses. The acquisition of FSY1 through HGT was sometimes suggestive of xenolog gene displacement, but several cases of pseudoparalogy were also uncovered. Moreover, evidence was found for successive HGT events, possibly including those responsible for transmission of the gene among yeast lineages. These occurrences do not seem to be driven by functional diversification of the Fsy1 proteins because Fsy1 homologues from widely distant lineages, including at least one acquired by HGT, appear to have similar biochemical properties. In summary, retracing the evolutionary path of the FSY1 gene brought to light an unparalleled number of independent HGT events involving a single fungal gene. We propose that the turbulent evolutionary history of the gene may be linked to the unique biochemical properties of the encoded transporter, whose predictable effect on fitness may be highly variable. In general, our results support the most recent views suggesting that inter-species HGT may have contributed much more substantially to shape fungal genomes than heretofore assumed.

  20. Sustaining an Effective ABC-ABM System

    Directory of Open Access Journals (Sweden)

    Gary COKINS

    2011-02-01

    Full Text Available The purpose of this paper is to describe the Activity- Based Costing (ABC and Activity-Based Management (ABM system and techniques to sustain them as a permanent and repeatable production reporting system, not just for one-off analysis. A comparison is made between ABC/ABM modeling software that extracts source data and business systems that include ABC/ABM modeling features. There are presented the stages of updating, running and rerunning the ABC/ABM system. The resulting information calculated and provided by the ABC/ABM system are analyzed and interpreted in terms of a multidimensional data analysis. The article ends with the authors' conclusions about the benefits of continued operation of sustaining the ABC/ABM system.

  1. Transport of tylosin and tylosin-resistance genes in subsurface drainage water from manured fields

    Science.gov (United States)

    Animal agriculture appears to contribute to the spread of antibiotic resistance genes, but few studies have quantified gene transport in agricultural fields. The transport of tylosin, tylosin-resistance genes (erm B, F, A) and tylosin-resistant Enterococcus were measured in tile drainage water from ...

  2. The ABC daycare disaster of Hermosillo, Mexico.

    Science.gov (United States)

    Greenhalgh, David G; Chang, Philip; Maguina, Pirko; Combs, Elena; Sen, Soman; Palmieri, Tina L

    2012-01-01

    On June 5, 2009, the ABC Daycare facility in Hermosillo, Mexico, caught on fire with an estimated 142 children and 6 adult caregivers inside. The purpose of this article is to describe the factors contributing to the disaster including care of the survivors, tertiary burn center triage, patient transport, and treatment for this international mass casualty event. Finally, the results of an investigation performed by the Mexican Government are reviewed. A summary of the Mexican Government's investigation of the circumstances of fire and an examination of prevention lapses in other Mexican daycare centers was obtained from their public Web site. The demographic and clinical characteristics of the children transported to the burn center were obtained from the patients' medical records and transport data sheets. The ABC Daycare had many fire safety breaches that contributed to the severity of the tragedy. Twenty-nine children died at the scene and more than 35 children were hospitalized throughout Mexico. A total of 12 children were transported to two Shriners Hospitals, 9 to Sacramento, and 3 to Cincinnati. The mean age of patients sent to the Shriners Hospitals was 2.9 ± 0.16 years (2-4 years), with 5 being male and 7 female. The mean duration between injury and arrival was 9.2 ± 2.1 days, the burn size was 43.0 ± 6.8% TBSA (6.5-80%), and there were 3.75 operations per patient. Four had fourth-degree burns requiring finger amputations (2), flaps to cover bone (1), or a through-knee amputation (1). Ten patients were admitted to the intensive care unit, and nine patients (seven with inhalation injury) required mechanical ventilation for a mean of 23.6 ± 10.3 days. All the surviving children were discharged after a mean length of stay of 45.9 ± 8.7 days. In the first year postinjury, seven children were readmitted a total of 11 times for reconstructive surgery, wound care, or rehabilitation. Ultimately, a total of 49 children died. A review of other daycare centers

  3. Further analysis of nitrogen fixation (nif) genes in Azotobacter chroococcum: identification and expression in Klebsiella pneumoniae of nifS, nifV, nifM, and nifB genes and localization of nifE/N-, nifU-, nifA- and fixABC-like genes.

    Science.gov (United States)

    Evans, D; Jones, R; Woodley, P; Robson, R

    1988-04-01

    The results presented extend previous investigations on the genetics of nitrogen fixation in Azotobacter chroococcum and indicate that nif- and fix-like DNA is located in at least five different regions of the genome. Region I contains functional copies of nifS,V and M, as well as nifH, D and K, all of which complemented mutants of Klebsiella pneumoniae. In addition, nifE- and/or nifN-like and nifU-like DNA is located in this region. The organization of the nif cluster in region I closely resembles that of K. pneumoniae. though spread over 22 kb as compared with 14 kb. Region II contains a functional nifB gene, which complemented a K. pneumoniae nifB mutant, and seems to be adjacent to ap nifA-like gene. Region III harbours nifH*, encoding a second nitrogenase Fe-protein. Region IV contains a reiteration of nifE- on and/or nifN-like sequences, and DNA homologous to Rhizobium meliloti fixABC is present in region V. The apparent complexity of nifDNA in A. chroococcum is probably related to the two systems for N2-fixation pr present in this organism.

  4. ABC model and floral evolution

    Institute of Scientific and Technical Information of China (English)

    LI Guisheng; MENG Zheng; KONG Hongzhi; CHEN Zhiduan; LU Anming

    2003-01-01

    The paper introduces the classical ABC model of floral development and thereafter ABCD, ABCDE and quartet models, and presents achievements in the studies on floral evolution such as the improved understanding on the relationship of reproductive organs between gnetophytes and angiosperms, new results in perianth evolution and identified homology of floral organs between dicots and monocots. The evo-devo studies on plant taxa at different evolutionary levels are useful to better understanding the homology of floral organs, and to clarifying the mysteries of the origin and subsequent diversification of flowers.

  5. Complex phylogeny and gene expression patterns of members of the NITRATE TRANSPORTER 1/PEPTIDE TRANSPORTER family (NPF) in wheat.

    Science.gov (United States)

    Buchner, Peter; Hawkesford, Malcolm J

    2014-10-01

    NPF (formerly referred to as low-affinity NRT1) and 'high-affinity' NRT2 nitrate transporter genes are involved in nitrate uptake by the root, and transport and distribution of nitrate within the plant. The NPF gene family consists of 53 members in Arabidopsis thaliana, however only 11 of these have been functionally characterized. Although homologous genes have been identified in genomes of different plant species including some cereals, there is little information available for wheat (Triticum aestivum). Sixteen genes were identified in wheat homologous to characterized Arabidopsis low-affinity nitrate transporter NPF genes, suggesting a complex wheat NPF gene family. The regulation of wheat NFP genes by plant N-status indicated involvement of these transporters in substrate transport in relation to N-metabolism. The complex expression pattern in relation to tissue specificity, nitrate availability and senescence may be associated with the complex growth patterns of wheat depending on sink/source demands, as well as remobilization during grain filling.

  6. Expression Patterns of Glucose Transporter-1 Gene and Thyroid Specific Genes in Human Papillary Thyroid Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sungeun; Chung, Junekey; Min Haesook and others

    2014-06-15

    The expression of glucose transporter-1 (Glut-1) gene and those of major thyroid-specific genes were examined in papillary carcinoma tissues, and the expressions of these genes were compared with cancer differentiation grades. Twenty-four human papillary carcinoma tissues were included in this study. The expressions of Glut-1- and thyroid-specific genes [sodium/iodide symporter (NIS), thyroid peroxidase, thyroglobulin, TSH receptor and pendrin] were analyzed by RT-PCR. Expression levels were expressed as ratios versus the expression of beta-actin. Pathologic differentiation of papillary carcinoma was classified into a relatively well-differentiated group (n=13) and relatively less differentiated group (n=11). Glut-1 gene expression was significantly higher in the less differentiated group (0.66±0.04) than in the well-differentiated group (0.59±0.07). The expression levels of the NIS, PD and TG genes were significantly higher in the well-differentiated group (NIS: 0.67±0.20, PD: 0.65±0.21, TG: 0.74±0.16) than in the less differentiated group (NIS: 0.36±0.05, PD: 0.49±0.08, TG: 0.60±0.11), respectively. A significant negative correlation was found between Glut-1 and NIS expression, and positive correlations were found between NIS and TG, and between NIS and PD. The NIS, PD and TG genes were highly expressed in well-differentiated thyroid carcinomas, whereas the Glut-1 gene was highly expressed in less differentiated thyroid carcinomas. These findings provide a molecular rationale for the management of papillary carcinoma, especially in the selection of FDG PET or radioiodine whole-body scan and I-131-based therapy.

  7. MALT1 small molecule inhibitors specifically suppress ABC-DLBCL in vitro and in vivo.

    Science.gov (United States)

    Fontan, Lorena; Yang, Chenghua; Kabaleeswaran, Venkataraman; Volpon, Laurent; Osborne, Michael J; Beltran, Elena; Garcia, Monica; Cerchietti, Leandro; Shaknovich, Rita; Yang, Shao Ning; Fang, Fang; Gascoyne, Randy D; Martinez-Climent, Jose Angel; Glickman, J Fraser; Borden, Katherine; Wu, Hao; Melnick, Ari

    2012-12-11

    MALT1 cleavage activity is linked to the pathogenesis of activated B cell-like diffuse large B cell lymphoma (ABC-DLBCL), a chemoresistant form of DLBCL. We developed a MALT1 activity assay and identified chemically diverse MALT1 inhibitors. A selected lead compound, MI-2, featured direct binding to MALT1 and suppression of its protease function. MI-2 concentrated within human ABC-DLBCL cells and irreversibly inhibited cleavage of MALT1 substrates. This was accompanied by NF-κB reporter activity suppression, c-REL nuclear localization inhibition, and NF-κB target gene downregulation. Most notably, MI-2 was nontoxic to mice, and displayed selective activity against ABC-DLBCL cell lines in vitro and xenotransplanted ABC-DLBCL tumors in vivo. The compound was also effective against primary human non-germinal center B cell-like DLBCLs ex vivo.

  8. An ABC for decision making

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Luiz Henrique Costa, E-mail: luiz_mogi@yahoo.com.br [Associacao de Medicina Intensiva Brasileira (AMIB), Sao Paulo, SP (Brazil); Irmandade da Santa Casa de Misericordia de Sao Paulo, SP (Brazil); Ferreira, Bruna Cortez [Hospital de Base de Sao Jose do Rio Preto, SP (Brazil)

    2015-03-15

    The present study was aimed at proposing a systematic evaluation of cranial computed tomography, identifying the main aspects to be analyzed in order to facilitate the decision making process regarding diagnosis and management in emergency settings. The present descriptive study comprised a literature review at the following databases: Access Medicine and Access Emergency Medicine (McGraw-Hill Education); British Medical Journal Evidence Center; UptoDate; Bireme; PubMed; Lilacs; SciELO; ProQuest; Micromedex (Thomson Reuters); Embase. Once the literature review was completed, the authors identified the main diseases with tomographic repercussions and proposed the present system to evaluate cranial computed tomography images. An easy-to-memorize ABC system will facilitate the decision making in emergency settings, as it covers the main diseases encountered by intensivists and emergency physicians, and provides a sequential guidance about anatomical structures to be investigated as well as their respective alterations. (author)

  9. An ABC for decision making.

    Science.gov (United States)

    Garcia, Luiz Henrique Costa; Ferreira, Bruna Cortez

    2015-01-01

    The present study was aimed at proposing a systematic evaluation of cranial computed tomography, identifying the main aspects to be analyzed in order to facilitate the decision making process regarding diagnosis and management in emergency settings. The present descriptive study comprised a literature review at the following databases: Access Medicine and Access Emergency Medicine (McGraw- Hill Education); British Medical Journal Evidence Center; UptoDate; Bireme; PubMed; Lilacs; SciELO; ProQuest; Micromedex (Thomson Reuters); Embase. Once the literature review was completed, the authors identified the main diseases with tomographic repercussions and proposed the present system to evaluate cranial computed tomography images. An easy-to-memorize ABC system will facilitate the decision making in emergency settings, as it covers the main diseases encountered by intensivists and emergency physicians, and provides a sequential guidance about anatomical structures to be investigated as well as their respective alterations.

  10. An ABC for decision making

    Directory of Open Access Journals (Sweden)

    Luiz Henrique Costa Garcia

    2015-04-01

    Full Text Available The present study was aimed at proposing a systematic evaluation of cranial computed tomography, identifying the main aspects to be analyzed in order to facilitate the decision making process regarding diagnosis and management in emergency settings. The present descriptive study comprised a literature review at the following databases: Access Medicine and Access Emergency Medicine (McGraw- Hill Education; British Medical Journal Evidence Center; UptoDate; Bireme; PubMed; Lilacs; SciELO; ProQuest; Micromedex (Thomson Reuters; Embase. Once the literature review was completed, the authors identified the main diseases with tomographic repercussions and proposed the present system to evaluate cranial computed tomography images. An easy-to-memorize ABC system will facilitate the decision making in emergency settings, as it covers the main diseases encountered by intensivists and emergency physicians, and provides a sequential guidance about anatomical structures to be investigated as well as their respective alterations.

  11. Culture-gene coevolution of individualism-collectivism and the serotonin transporter gene.

    Science.gov (United States)

    Chiao, Joan Y; Blizinsky, Katherine D

    2010-02-22

    Culture-gene coevolutionary theory posits that cultural values have evolved, are adaptive and influence the social and physical environments under which genetic selection operates. Here, we examined the association between cultural values of individualism-collectivism and allelic frequency of the serotonin transporter functional polymorphism (5-HTTLPR) as well as the role this culture-gene association may play in explaining global variability in prevalence of pathogens and affective disorders. We found evidence that collectivistic cultures were significantly more likely to comprise individuals carrying the short (S) allele of the 5-HTTLPR across 29 nations. Results further show that historical pathogen prevalence predicts cultural variability in individualism-collectivism owing to genetic selection of the S allele. Additionally, cultural values and frequency of S allele carriers negatively predict global prevalence of anxiety and mood disorder. Finally, mediation analyses further indicate that increased frequency of S allele carriers predicted decreased anxiety and mood disorder prevalence owing to increased collectivistic cultural values. Taken together, our findings suggest culture-gene coevolution between allelic frequency of 5-HTTLPR and cultural values of individualism-collectivism and support the notion that cultural values buffer genetically susceptible populations from increased prevalence of affective disorders. Implications of the current findings for understanding culture-gene coevolution of human brain and behaviour as well as how this coevolutionary process may contribute to global variation in pathogen prevalence and epidemiology of affective disorders, such as anxiety and depression, are discussed.

  12. The Vitis vinifera sugar transporter gene family: phylogenetic overview and macroarray expression profiling

    Directory of Open Access Journals (Sweden)

    Atanassova Rossitza

    2010-11-01

    Full Text Available Abstract Background In higher plants, sugars are not only nutrients but also important signal molecules. They are distributed through the plant via sugar transporters, which are involved not only in sugar long-distance transport via the loading and the unloading of the conducting complex, but also in sugar allocation into source and sink cells. The availability of the recently released grapevine genome sequence offers the opportunity to identify sucrose and monosaccharide transporter gene families in a woody species and to compare them with those of the herbaceous Arabidopsis thaliana using a phylogenetic analysis. Results In grapevine, one of the most economically important fruit crop in the world, it appeared that sucrose and monosaccharide transporter genes are present in 4 and 59 loci, respectively and that the monosaccharide transporter family can be divided into 7 subfamilies. Phylogenetic analysis of protein sequences has indicated that orthologs exist between Vitis and Arabidospis. A search for cis-regulatory elements in the promoter sequences of the most characterized transporter gene families (sucrose, hexoses and polyols transporters, has revealed that some of them might probably be regulated by sugars. To profile several genes simultaneously, we created a macroarray bearing cDNA fragments specific to 20 sugar transporter genes. This macroarray analysis has revealed that two hexose (VvHT1, VvHT3, one polyol (VvPMT5 and one sucrose (VvSUC27 transporter genes, are highly expressed in most vegetative organs. The expression of one hexose transporter (VvHT2 and two tonoplastic monosaccharide transporter (VvTMT1, VvTMT2 genes are regulated during berry development. Finally, three putative hexose transporter genes show a preferential organ specificity being highly expressed in seeds (VvHT3, VvHT5, in roots (VvHT2 or in mature leaves (VvHT5. Conclusions This study provides an exhaustive survey of sugar transporter genes in Vitis vinifera and

  13. Synthesis and modulation properties of imidazo[4,5-b]pyridin-7-one and indazole-4,7-dione derivatives towards the Cryptosporidium parvum CpABC3 transporter.

    Science.gov (United States)

    Zeinyeh, Waël; Xia, Hexue; Lawton, Philippe; Radix, Sylvie; Marminon, Christelle; Nebois, Pascal; Walchshofer, Nadia

    2010-06-01

    The syntheses of new N-polysubstituted imidazo[4,5-b]pyridine-7-one (IP, 5 and 8a-8f) and indazole-4,7-dione (ID, 9 and 10) derivatives are described. The binding affinity of IP and ID towards the recombinant Nucleotide Binding Domain NBD1 of Cryptosporidium parvum CpABC3 was evaluated by intrinsic fluorescence quenching. IP induced a moderate quenching of the intrinsic fluorescence of H6-NBD1 whereas IDs 9 and 10 showed a binding affinity comparable to the ATP analogue TNP-ATP. In addition, 8d, 8e and 10 were shown to be competitive inhibitors of the ATPase activity, but with low affinity. These compounds could thus act like some flavonoid derivatives, which can partly overlap both the nucleotide-binding site and the adjacent hydrophobic steroid-binding region of mammalian P-glycoproteins.

  14. Applying the ABCs in provider organizations.

    Science.gov (United States)

    Pandey, Seema

    2012-11-01

    Activity-based costing (ABC) is an accounting technique designed to guard against potentially serious financial problems that can arise when an organization's accounting costs deviate significantly from its actual costs. In general, an ABC analysis considers two factors: a cost element (a directly measurable unit of cost, such as the cost of an item) and a cost driver (a directly measurable feature of the service, such as how often the item is used). ABC is best applied to specific service areas, orservice packages, for which consumption of resources is largely predictable and atomic units of services can be accurately identified.

  15. The gusBC genes of Escherichia coli encode a glucuronide transport system

    NARCIS (Netherlands)

    Liang, WJ; Wilson, KJ; Xie, H; Knol, J; Suzuki, S; Rutherford, NG; Henderson, PJF; Jefferson, RA

    2005-01-01

    Two genes, gusB and gusC, from a natural fecal isolate of Escherichia coli are shown to encode proteins responsible for transport of beta-glucuronides with synthetic [C-14] phenyl-l-thio-beta-D-glucuronide as the substrate. These genes are located in the gus operon downstream of the gusA gene on the

  16. Influence of the yjiL-mdtM Gene Cluster on the Antibacterial Activity of Proline-Rich Antimicrobial Peptides Overcoming Escherichia coli Resistance Induced by the Missing SbmA Transporter System.

    Science.gov (United States)

    Krizsan, Andor; Knappe, Daniel; Hoffmann, Ralf

    2015-10-01

    In view of increasing health threats from multiresistant pathogens, antimicrobial peptides (AMPs) and, specifically, proline-rich AMPs (PrAMPs) have been investigated in animal models. PrAMPs enter bacteria via the ABC transporter SbmA and inhibit intracellular targets. We used phage transduction (Tn10 insertion) to screen by random mutagenesis for alternative uptake mechanisms for analogs of apidaecin 1b, a honeybee-derived PrAMP. All 24 apidaecin-resistant mutants had the Tn10 insertion in the sbmA gene. These sbmA::Tn10 insertion mutants and the Escherichia coli BW25113 ΔsbmA (JW0368) strain were still susceptible to the bactenecin PrAMP Bac7(1-35) and oncocin PrAMPs Onc18 and Onc112, as well as to Chex1-Arg20, despite significantly reduced internalizations. In a second round of random mutagenesis, the remaining susceptibility was linked to the yjiL-mdtM gene cluster. E. coli BW25113 and its ΔyjiL null mutant (JW5785) were equally susceptible to all PrAMPs tested, whereas the BW25113 ΔmdtM mutant was less susceptible to oncocins. The JW0368 yjiL::Tn10 transposon mutant (BS2) was resistant to all short PrAMPs and susceptible only to full-length Bac7 and A3-APO. Interestingly, PrAMPs appear to enter bacteria via MdtM, a multidrug resistance transporter (drug/H(+) antiporter) of the major facilitator superfamily (MFS) that can efflux antibiotics, biocides, and bile salts. In conclusion, PrAMPs enter bacteria via ABC and MFS transporters that efflux antibiotics and cytotoxic compounds from the cytoplasm to the periplasm.

  17. The association of the dopamine transporter gene and the dopamine receptor 2 gene with delirium: a meta-analysis.

    NARCIS (Netherlands)

    Munster, B.C. van; Rooij, S.E.J.A. de; Yazdanpanah, M.; Tienari, P.J.; Pitkala, K.H.; Osse, R.J.; Adamis, D.; Smit, O.; Steen, M.S. van der; Houten, M. van; Rahkonen, T.; Sulkava, R.; Laurila, J.V.; Strandberg, T.E.; Tulen, J.H.M.; Zwang, L.; Macdonald, A.J.D.; Treloar, A.; Sijbrands, E.J.G.; Zwinderman, A.H.; Korevaar, J.C.

    2010-01-01

    Delirium is the most common neuropsychiatric syndrome in elderly ill patients. Previously, associations between delirium and the dopamine transporter gene (solute carrier family 6, member 3 (SLC6A3)) and dopamine receptor 2 gene (DRD2) were found. The aim of this study was to validate whether marker

  18. ABCs of Oral Health: Nutrition - Children

    Science.gov (United States)

    ... abnormal facial and dental development More ABCs of Oral Health A | B | C | D | E | F | G | H | ... games Home | InfoBites | Find a Dentist | Your Family's Oral Health | Newsroom | RSS About AGD | Contact AGD | Site Map | ...

  19. Genome wide identification, phylogeny and expression of zinc transporter genes in common carp.

    Directory of Open Access Journals (Sweden)

    Yanliang Jiang

    Full Text Available BACKGROUND: Zinc is an essential trace element in organisms, which serves as a cofactor for hundreds of enzymes that are involved in many pivotal biological processes including growth, development, reproduction and immunity. Therefore, the homeostasis of zinc in the cell is fundamental. The zinc transporter gene family is a large gene family that encodes proteins which regulate the movement of zinc across cellular and intracellular membranes. However, studies on teleost zinc transporters are mainly limited to model species. METHODOLOGY/PRINCIPAL FINDINGS: We identified a set of 37 zinc transporters in common carp genome, including 17 from SLC30 family (ZnT, and 20 from SLC39 family (ZIP. Phylogenetic and syntenic analysis revealed that most of the zinc transporters are highly conserved, though recent gene duplication and gene losses do exist. Through examining the copy number of zinc transporter genes across several vertebrate genomes, thirteen zinc transporters in common carp are found to have undergone the gene duplications, including SLC30A1, SLC30A2, SLC30A5, SLC30A7, SLC30A9, SLC30A10, SLC39A1, SLC39A3, SLC39A4, SLC39A5, SLC39A6, SLC39A7 and SLC39A9. The expression patterns of all zinc transporters were established in various tissues, including blood, brain, gill, heart, intestine, liver, muscle, skin, spleen and kidney, and showed that most of the zinc transporters were ubiquitously expressed, indicating the critical role of zinc transporters in common carp. CONCLUSIONS: To some extent, examination of gene families with detailed phylogenetic or orthology analysis could verify the authenticity and accuracy of assembly and annotation of the recently published common carp whole genome sequences. The gene families are also considered as a unique source for evolutionary studies. Moreover, the whole set of common carp zinc transporters provides an important genomic resource for future biochemical, toxicological and physiological studies of zinc

  20. Multidrug resistance in Botrytis cinerea associated with decreased accumulation of the azole fungicide oxpoconazole and increased transcription of the ABC transporter gene BcatrD

    NARCIS (Netherlands)

    Hayashi, K.; Schoonbeek, H.; Sugiura, H.; Waard, De M.A.

    2001-01-01

    Azole-resistant mutants of Botrytis cinerea have a multidrug resistance phenotype since they exhibit cross-resistance to unrelated chemicals. These mutants also display resistance to the new azole fungicide oxpoconazole. Resistance to oxpoconazole is associated with decreased accumulation of the fun

  1. Transport genes and chemotaxis in Laribacter hongkongensis: a genome-wide analysis

    Directory of Open Access Journals (Sweden)

    Lau Susanna KP

    2011-08-01

    Full Text Available Abstract Background Laribacter hongkongensis is a Gram-negative, sea gull-shaped rod associated with community-acquired gastroenteritis. The bacterium has been found in diverse freshwater environments including fish, frogs and drinking water reservoirs. Using the complete genome sequence data of L. hongkongensis, we performed a comprehensive analysis of putative transport-related genes and genes related to chemotaxis, motility and quorum sensing, which may help the bacterium adapt to the changing environments and combat harmful substances. Results A genome-wide analysis using Transport Classification Database TCDB, similarity and keyword searches revealed the presence of a large diversity of transporters (n = 457 and genes related to chemotaxis (n = 52 and flagellar biosynthesis (n = 40 in the L. hongkongensis genome. The transporters included those from all seven major transporter categories, which may allow the uptake of essential nutrients or ions, and extrusion of metabolic end products and hazardous substances. L. hongkongensis is unique among closely related members of Neisseriaceae family in possessing higher number of proteins related to transport of ammonium, urea and dicarboxylate, which may reflect the importance of nitrogen and dicarboxylate metabolism in this assacharolytic bacterium. Structural modeling of two C4-dicarboxylate transporters showed that they possessed similar structures to the determined structures of other DctP-TRAP transporters, with one having an unusual disulfide bond. Diverse mechanisms for iron transport, including hemin transporters for iron acquisition from host proteins, were also identified. In addition to the chemotaxis and flagella-related genes, the L. hongkongensis genome also contained two copies of qseB/qseC homologues of the AI-3 quorum sensing system. Conclusions The large number of diverse transporters and genes involved in chemotaxis, motility and quorum sensing suggested that the bacterium may

  2. Functional analysis of the ABCs of eye color in Helicoverpa armigera with CRISPR/Cas9-induced mutations

    Science.gov (United States)

    Khan, Sher Afzal; Reichelt, Michael; Heckel, David G.

    2017-01-01

    Many insect pigments are localized in subcellular pigment granules, and transport of pigment precursors from the cytoplasm is accomplished by ABC proteins. Drosophila melanogaster has three half-transporter genes (white, scarlet, and brown, all affecting eye pigments) and Bombyx mori has a fourth (ok). The White, Brown, Scarlet and Ok proteins each have one transmembrane and one cytoplasmic domain and they heterodimerize to form functional transporters with different substrate specificities. We used CRISPR/Cas9 to create somatic and germ-line knockout mutations of these four genes in the noctuid moth Helicoverpa armigera. Somatic knockouts of white block pigmentation of the egg, first instar larva and adult eye, but germ-line knockouts of white are recessive lethal in the embryo. Knockouts of scarlet are viable and produce pigmentless first instar larvae and yellow adult eyes lacking xanthommatin. Knockouts of brown show no phenotypic effects on viability or pigmentation. Knockouts of ok are viable and produce translucent larval cuticle and black eyes. CRISPR/Cas9-induced mutations are a useful tool for analyzing how essential and non-essential genes interact to produce the diversity of insect pigmentation patterns found in nature. PMID:28053351

  3. Polymorphisms in Plasmodium falciparum chloroquine resistance transporter and multidrug resistance 1 genes

    DEFF Research Database (Denmark)

    Venkatesan, Meera; Gadalla, Nahla B; Stepniewska, Kasia;

    2014-01-01

    Adequate clinical and parasitologic cure by artemisinin combination therapies relies on the artemisinin component and the partner drug. Polymorphisms in the Plasmodium falciparum chloroquine resistance transporter (pfcrt) and P. falciparum multidrug resistance 1 (pfmdr1) genes are associated...

  4. The ABC-paradox: is Time Driven ABC relevant for small and Medium sized enterprises (SME)?

    DEFF Research Database (Denmark)

    Fladkjær, Henrik Find; Jensen, Erling

    Several articles suggest that Activity Based Costing (ABC) has failed to succeed in practical use. It is even argued that we have an ABC-paradox. Activity Based Costing has won theoretically in nu-merous articles in journals, through books, being included in all major Business Accounting text...

  5. Deduced products of C4-dicarboxylate transport regulatory genes of Rhizobium leguminosarum are homologous to nitrogen regulatory gene products.

    OpenAIRE

    Ronson, C W; Astwood, P M; Nixon, B T; Ausubel, F M

    1987-01-01

    We have sequenced two genes dctB and dctD required for the activation of the C4-dicarboxylate transport structural gene dctA in free-living Rhizobium leguminosarum. The hydropathic profile of the dctB gene product (DctB) suggested that its N-terminal region may be located in the periplasm and its C-terminal region in the cytoplasm. The C-terminal region of DctB was strongly conserved with similar regions of the products of several regulatory genes that may act as environmental sensors, includ...

  6. Serotonin transporter gene polymorphisms in irritable bowel syndrome and their impact on tegaserod treatment

    Institute of Scientific and Technical Information of China (English)

    李瑜元

    2006-01-01

    Objective To investigate the serotonin reuptake transporter (SERT) genetic polymorphisms in the 5 -hydroxytryptamine (5-HT) transporter gene-linked polymorphic region (5-HTTLPR) and the variable number tandem repeats (VNTRs) in intron 2 among Chinese people, and their relationship to the pathogenesis of irritable bowel syndrome (IBS);and to investigate the im-

  7. Functional characterization of the Escherichia coli K-12 yiaMNO transport protein genes

    NARCIS (Netherlands)

    Plantinga, TH; van der Does, C; Badia, J; Aguilar, J; Konings, WN; Driessen, AJM; Plantinga, Titia H.

    2004-01-01

    The yiaMNO genes of Escherichia coli K-12 encode a binding protein-dependent secondary, or tri-partite ATP-independent periplasmic (TRAP), transporter. Since only a few members of this family have been functionally characterized to date, we aimed to identify the substrate for this transporter. Cells

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

    Science.gov (United States)

    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.

  9. The role of ATP-binding cassette transporter A2 in childhood acute lymphoblastic leukemia multidrug resistance

    OpenAIRE

    Aberuyi, N; Rahgozar, S; Moafi, A

    2014-01-01

    Acute lymphoblastic leukemia (ALL) is one of the most prevalent hematologic malignancies in children. Although the cure rate of ALL has improved over the past decades, the most important reason for ALL treatment failure is multidrug resistance (MDR) phenomenon. The current study aims to explain the mechanisms involved in multidrug resistance of childhood ALL, and introduces ATP-binding cassette transporterA2 (ABCA2) as an ABC transporter gene which may have a high impact on MDR. Benefiting fr...

  10. Identification of a novel sialic acid transporter in Haemophilus ducreyi.

    Science.gov (United States)

    Post, Deborah M B; Mungur, Rachna; Gibson, Bradford W; Munson, Robert S

    2005-10-01

    Haemophilus ducreyi, the causative agent of chancroid, produces a lipooligosaccharide (LOS) which terminates in N-acetyllactosamine. This glycoform can be further extended by the addition of a single sialic acid residue to the terminal galactose moiety. H. ducreyi does not synthesize sialic acid, which must be acquired from the host during infection or from the culture medium when the bacteria are grown in vitro. However, H. ducreyi does not have genes that are highly homologous to the genes encoding known bacterial sialic acid transporters. In this study, we identified the sialic acid transporter by screening strains in a library of random transposon mutants for those mutants that were unable to add sialic acid to N-acetyllactosamine-containing LOS. Mutants that reacted with the monoclonal antibody 3F11, which recognizes the terminal lactosamine structure, and lacked reactivity with the lectin Maackia amurensis agglutinin, which recognizes alpha2,3-linked sialic acid, were further characterized to demonstrate that they produced a N-acetyllactosamine-containing LOS by silver-stained sodium dodecyl sulfate-polyacrylamide gel electrophoresis and mass spectrometric analyses. The genes interrupted in these mutants were mapped to a four-gene cluster with similarity to genes encoding bacterial ABC transporters. Uptake assays using radiolabeled sialic acid confirmed that the mutants were unable to transport sialic acid. This study is the first report of bacteria using an ABC transporter for sialic acid uptake.

  11. H-1 magnetic resonance spectroscopy in monocarboxylate transporter 8 gene deficiency

    NARCIS (Netherlands)

    Sijens, Paul E.; Rodiger, Lars A.; Meiners, Linda C.; Lunsing, Roelineke J.

    2008-01-01

    Context: In monocarboxylate transporter 8 (MCT8) gene deficiency, a syndrome combining thyroid and neurological abnormalities, the central nervous system has not yet been characterized by magnetic resonance (MR) spectroscopy. Objective: We studied whether the degree of dysmyelinization in MCT8 gene

  12. Isolation and cloning of the gene encoding high affinity phosphate transporter in rice

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    High affinity phosphate transporter plays an important role in plant adapting to low phosphorus. Isolation of genes coding this kind of protein has attracted worldwide scholars to accomplish. We aimed to isolate the gene and transfer it to target plants for breeding.

  13. Nutrient uptake by marine invertebrates: cloning and functional analysis of amino acid transporter genes in developing sea urchins (Strongylocentrotus purpuratus).

    Science.gov (United States)

    Meyer, Eli; Manahan, Donal T

    2009-08-01

    Transport of amino acids from low concentrations in seawater by marine invertebrates has been extensively studied, but few of the genes involved in this physiological process have been identified. We have characterized three amino acid transporter genes cloned from embryos of the sea urchin Strongylocentrotus purpuratus. These genes show phylogenetic proximity to classical amino acid transport systems, including Gly and B0+, and the inebriated gene (INE). Heterologous expression of these genes in frog oocytes induced a 40-fold increase in alanine transport above endogenous levels, demonstrating that these genes mediate alanine transport. Antibodies specific to one of these genes (Sp-AT1) inhibited alanine transport, confirming the physiological activity of this gene in larvae. Whole-mount antibody staining of larvae revealed expression of Sp-AT1 in the ectodermal tissues associated with amino acid transport, as independently demonstrated by autoradiographic localization of radioactive alanine. Maximum rates of alanine transport increased 6-fold during early development, from embryonic to larval stages. Analysis of gene expression during this developmental period revealed that Sp-AT1 transcript abundance remained nearly constant, while that of another transporter gene (Sp-AT2) increased 11-fold. The functional characterization of these genes establishes a molecular biological basis for amino acid transport by developmental stages of marine invertebrates.

  14. An ABC analysis for power generation project

    Directory of Open Access Journals (Sweden)

    Batool Hasani

    2013-07-01

    Full Text Available One of the primary concerns on performance measurement is to know how much a particular project cost. However, using traditional method on project-based products often leads to inappropriate results. In this paper, we re-examine this issue by comparing the cost of a power station construction project using ABC versus traditional method. The results of survey show that ABC method is capable of providing better estimates for overhead costs compared with traditional method. In other words, ABC method helps reduce some of the unnecessary overhead cost items and increase on some other cost components. This helps increase the relative efficiency of the system by reducing total cost of project.

  15. The Liver X Receptor (LXR) and its Target Gene ABCA1 are Regulated Upon Low Oxygen in Human Trophoblast Cells : A Reason for Alterations in Preeclampsia?

    NARCIS (Netherlands)

    Plosch, T.; Gellhaus, A.; van Straten, E. M. E.; Wolf, N.; Huijkman, N. C. A.; Schmidt, M.; Dunk, C. E.; Kuipers, F.; Winterhager, E.

    2010-01-01

    Objectives: The Liver X receptors (LXR) alpha and beta and their target genes such as the ATP-binding cassette (ABC) transporters have been shown to be crucially involved in the regulation of cellular cholesterol homeostasis. The aim of this study was to characterize the role of LXR alpha/beta in th

  16. Bacterial transport of sulfate, molybdate, and related oxyanions.

    Science.gov (United States)

    Aguilar-Barajas, Esther; Díaz-Pérez, César; Ramírez-Díaz, Martha I; Riveros-Rosas, Héctor; Cervantes, Carlos

    2011-08-01

    Sulfur is an essential element for microorganisms and it can be obtained from varied compounds, sulfate being the preferred source. The first step for sulfate assimilation, sulfate uptake, has been studied in several bacterial species. This article reviews the properties of different bacterial (and archaeal) transporters for sulfate, molybdate, and related oxyanions. Sulfate uptake is carried out by sulfate permeases that belong to the SulT (CysPTWA), SulP, CysP/(PiT), and CysZ families. The oxyanions molybdate, tungstate, selenate and chromate are structurally related to sulfate. Molybdate is transported mainly by the high-affinity ModABC system and tungstate by the TupABC and WtpABC systems. CysPTWA, ModABC, TupABC, and WtpABC are homologous ATP-binding cassette (ABC)-type transporters with similar organization and properties. Uptake of selenate and chromate oxyanions occurs mainly through sulfate permeases.

  17. Disruption of a cystine transporter downregulates expression of genes involved in sulfur regulation and cellular respiration

    Directory of Open Access Journals (Sweden)

    Jessica A. Simpkins

    2016-06-01

    Full Text Available Cystine and cysteine are important molecules for pathways such as redox signaling and regulation, and thus identifying cellular deficits upon deletion of the Saccharomyces cerevisiae cystine transporter Ers1p allows for a further understanding of cystine homeostasis. Previous complementation studies using the human ortholog suggest yeast Ers1p is a cystine transporter. Human CTNS encodes the protein Cystinosin, a cystine transporter that is embedded in the lysosomal membrane and facilitates the export of cystine from the lysosome. When CTNS is mutated, cystine transport is disrupted, leading to cystine accumulation, the diagnostic hallmark of the lysosomal storage disorder cystinosis. Here, we provide biochemical evidence for Ers1p-dependent cystine transport. However, the accumulation of intracellular cystine is not observed when the ERS1 gene is deleted from ers1-Δ yeast, supporting the existence of modifier genes that provide a mechanism in ers1-Δ yeast that prevents or corrects cystine accumulation. Upon comparison of the transcriptomes of isogenic ERS1+ and ers1-Δ strains of S. cerevisiae by DNA microarray followed by targeted qPCR, sixteen genes were identified as being differentially expressed between the two genotypes. Genes that encode proteins functioning in sulfur regulation, cellular respiration, and general transport were enriched in our screen, demonstrating pleiotropic effects of ers1-Δ. These results give insight into yeast cystine regulation and the multiple, seemingly distal, pathways that involve proper cystine recycling.

  18. Disruption of a cystine transporter downregulates expression of genes involved in sulfur regulation and cellular respiration

    Science.gov (United States)

    Simpkins, Jessica A.; Rickel, Kirby E.; Madeo, Marianna; Ahlers, Bethany A.; Carlisle, Gabriel B.; Nelson, Heidi J.; Cardillo, Andrew L.; Weber, Emily A.; Vitiello, Peter F.; Pearce, David A.

    2016-01-01

    ABSTRACT Cystine and cysteine are important molecules for pathways such as redox signaling and regulation, and thus identifying cellular deficits upon deletion of the Saccharomyces cerevisiae cystine transporter Ers1p allows for a further understanding of cystine homeostasis. Previous complementation studies using the human ortholog suggest yeast Ers1p is a cystine transporter. Human CTNS encodes the protein Cystinosin, a cystine transporter that is embedded in the lysosomal membrane and facilitates the export of cystine from the lysosome. When CTNS is mutated, cystine transport is disrupted, leading to cystine accumulation, the diagnostic hallmark of the lysosomal storage disorder cystinosis. Here, we provide biochemical evidence for Ers1p-dependent cystine transport. However, the accumulation of intracellular cystine is not observed when the ERS1 gene is deleted from ers1-Δ yeast, supporting the existence of modifier genes that provide a mechanism in ers1-Δ yeast that prevents or corrects cystine accumulation. Upon comparison of the transcriptomes of isogenic ERS1+ and ers1-Δ strains of S. cerevisiae by DNA microarray followed by targeted qPCR, sixteen genes were identified as being differentially expressed between the two genotypes. Genes that encode proteins functioning in sulfur regulation, cellular respiration, and general transport were enriched in our screen, demonstrating pleiotropic effects of ers1-Δ. These results give insight into yeast cystine regulation and the multiple, seemingly distal, pathways that involve proper cystine recycling. PMID:27142334

  19. Transport and transformation of genetic information in the critical zone: The case of antibiotic resistance genes

    Science.gov (United States)

    Zhu, Y. G.

    2015-12-01

    In addition to material and energy flows, the dynamics and functions of the Earth's critical zone are intensively mediated by biological actions performed by diverse organisms. These biological actions are modulated by the expression of functional genes and their translation into enzymes that catalyze geochemical reactions, such as nutrient turnover and pollutant biodegradation. Although geobiology, as an interdisciplinary research area, is playing and vital role in linking biological and geochemical processes at different temporal and spatial scales, the distribution and transport of functional genes have rarely been investigated from the Earth's critical zone perspectives. To illustrate the framework of studies on the transport and transformation of genetic information in the critical zone, antibiotic resistance is taken as an example. Antibiotic resistance genes are considered as a group of emerging contaminants, and their emergence and spread within the critical zone on one hand are induced by anthropogenic activities, and on other hand are threatening human health worldwide. The transport and transformation of antibiotic resistance genes are controlled by both horizontal gene transfer between bacterial cells and the movement of bacteria harboring antibiotic resistance genes. In this paper, the fate and behavior of antibiotic resistance genes will be discussed in the following aspects: 1) general overview of environmental antibiotic resistance; 2) high through quantification of the resistome in various environmental media; 3) pathways of resistance gene flow within the critical zone; and 4) potential strategies in mitigating antibiotic resistance, particularly from the critical zone perspectives.

  20. An Electrically Tight In Vitro Blood-Brain Barrier Model Displays Net Brain-to-Blood Efflux of Substrates for the ABC Transporters, P-gp, Bcrp and Mrp-1

    DEFF Research Database (Denmark)

    Helms, Hans Christian; Hersom, Maria; Kuhlmann, Louise Borella;

    2014-01-01

    Efflux transporters of the ATP-binding cassette superfamily including breast cancer resistance protein (Bcrp/Abcg2), P-glycoprotein (P-gp/Abcb1) and multidrug resistance-associated proteins (Mrp's/Abcc's) are expressed in the blood-brain barrier (BBB). The aim of this study was to investigate......, zosuquidar, reversan and MK 571 alone or in combinations. Digoxin was mainly transported via P-gp, estrone-3-sulphate via Bcrp and Mrp's and etoposide via P-gp and Mrp's. The expression of P-gp, Bcrp and Mrp-1 was confirmed using immunocytochemistry. The findings indicate that P-gp, Bcrp and at least one...... isoform of Mrp are functionally expressed in our bovine/rat co-culture model and that the model is suitable for investigations of small molecule transport....

  1. An electrically tight in vitro blood-brain barrier model displays net brain-to-blood efflux of substrates for the ABC transporters, P-gp, Bcrp and Mrp-1.

    Science.gov (United States)

    Helms, Hans Christian; Hersom, Maria; Kuhlmann, Louise Borella; Badolo, Lasina; Nielsen, Carsten Uhd; Brodin, Birger

    2014-09-01

    Efflux transporters of the ATP-binding cassette superfamily including breast cancer resistance protein (Bcrp/Abcg2), P-glycoprotein (P-gp/Abcb1) and multidrug resistance-associated proteins (Mrp's/Abcc's) are expressed in the blood-brain barrier (BBB). The aim of this study was to investigate if a bovine endothelial/rat astrocyte in vitro BBB co-culture model displayed polarized transport of known efflux transporter substrates. The co-culture model displayed low mannitol permeabilities of 0.95 ± 0.1 · 10(-6) cm·s(-1) and high transendothelial electrical resistances of 1,177 ± 101 Ω·cm(2). Bidirectional transport studies with (3)H-digoxin, (3)H-estrone-3-sulphate and (3)H-etoposide revealed polarized transport favouring the brain-to-blood direction for all substrates. Steady state efflux ratios of 2.5 ± 0.2 for digoxin, 4.4 ± 0.5 for estrone-3-sulphate and 2.4 ± 0.1 for etoposide were observed. These were reduced to 1.1 ± 0.08, 1.4 ± 0.2 and 1.5 ± 0.1, by addition of verapamil (digoxin), Ko143 (estrone-3-sulphate) or zosuquidar + reversan (etoposide), respectively. Brain-to-blood permeability of all substrates was investigated in the presence of the efflux transporter inhibitors verapamil, Ko143, zosuquidar, reversan and MK 571 alone or in combinations. Digoxin was mainly transported via P-gp, estrone-3-sulphate via Bcrp and Mrp's and etoposide via P-gp and Mrp's. The expression of P-gp, Bcrp and Mrp-1 was confirmed using immunocytochemistry. The findings indicate that P-gp, Bcrp and at least one isoform of Mrp are functionally expressed in our bovine/rat co-culture model and that the model is suitable for investigations of small molecule transport.

  2. New Broom To Sweep Clean At ABC

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Agricultural Bank of China (ABC) has a new president. The last non- publicly traded state-owned lender in China announced on July 6 that Xiang Junbo, former Vice Governor of the People’s Bank of China, or the central bank, had beenappointed to take o

  3. WeltABC | kinderKAMERA

    Directory of Open Access Journals (Sweden)

    Christian Schreger

    2013-09-01

    Full Text Available Das WeltABC ist eine Einladung zur Reise durch Sprache(n und damit verknüpften Bildern. Es ist eine Sammlung scheinbar klarer Begriffe, deren Ausgangspunkt die Sprache Deutsch ist. Diese Begriffe werden mit weiteren Begriffen assoziiert und durch Fotos illustriert.

  4. Active Transport of Phosphorylated Carbohydrates Promotes Intestinal Colonization and Transmission of a Bacterial Pathogen.

    Directory of Open Access Journals (Sweden)

    Brandon Sit

    2015-08-01

    Full Text Available Efficient acquisition of extracellular nutrients is essential for bacterial pathogenesis, however the identities and mechanisms for transport of many of these substrates remain unclear. Here, we investigate the predicted iron-binding transporter AfuABC and its role in bacterial pathogenesis in vivo. By crystallographic, biophysical and in vivo approaches, we show that AfuABC is in fact a cyclic hexose/heptose-phosphate transporter with high selectivity and specificity for a set of ubiquitous metabolites (glucose-6-phosphate, fructose-6-phosphate and sedoheptulose-7-phosphate. AfuABC is conserved across a wide range of bacterial genera, including the enteric pathogens EHEC O157:H7 and its murine-specific relative Citrobacter rodentium, where it lies adjacent to genes implicated in sugar sensing and acquisition. C. rodentium ΔafuA was significantly impaired in an in vivo murine competitive assay as well as its ability to transmit infection from an afflicted to a naïve murine host. Sugar-phosphates were present in normal and infected intestinal mucus and stool samples, indicating that these metabolites are available within the intestinal lumen for enteric bacteria to import during infection. Our study shows that AfuABC-dependent uptake of sugar-phosphates plays a critical role during enteric bacterial infection and uncovers previously unrecognized roles for these metabolites as important contributors to successful pathogenesis.

  5. EFEKTIVITAS IMPLEMENTASI CORPORATE SOCIAL RESPOSIBILITY PT. ABC

    Directory of Open Access Journals (Sweden)

    Rizkiaji Rikky Djunaedi

    2015-12-01

    Full Text Available The purposes of this study were 1 to analyze public perceptions on the effectiveness of the implementation of CSR of PT. A B C; 2 to analyze the implementation of CSR activities by PT. A B C; 3 to formulate strategies to improve the effectiveness of the implementation of CSR of PT. A B C. The method used in this research was descriptive analysis with a survey approach to measure expectations and performance assessment on the CSR implemented programs by the public, and there were respondents 104 respondents involved in this study. This study used the Importance-Performance Analysis (IPA aiming to determine the effectiveness of the programs that have been implemented and to map the relationship between the expectations and the performance of each variable. Furthermore, using a SWOT analysis of the data processing and of the objectives of the program made by CSR is expected to provide recommendations to develop strategies in order to increase the effectiveness of CSR program of ABC Company.Keywords: corporate social responsibility (CSR, mining industry, implementation analysis, IPA, SWOTAbstrakTujuan dari  penelitian ini adalah 1 menganalisis persepsi masyarakat teradap efektivitas implementasi CSR PT. ABC; 2 menganalisis pelaksanaan  kegiatan CSR oleh PT. ABC; 3 merumuskan strategi untuk meningkatkan efektivitas implementasi CSR PT. ABC. Metode yang digunakan dalam penelitian ini adalah analisis deskriptif dengan pendekatan survey untuk mengukur harapan dan penilaian kinerja oleh masyarakat atas program CSR yang diterapkan. Jumlah responden sebanyak 104 orang.  Dalam penelitian ini digunakan Analisis Importance-Performance Analysis (IPA bertujuan untuk mengetahui efektifitas dari program-program yang telah dijalankan serta  memetakan hubungan antara harapan dengan kinerja dari masing-masing variabel. Selanjutnya menggunakan analisis SWOT dari hasil pengolahan data dan dari tujuan program dibuat oleh CSR sehingga dapat memberikan rekomendasi

  6. The replication origin of a repABC plasmid

    Directory of Open Access Journals (Sweden)

    Cevallos Miguel A

    2011-06-01

    Full Text Available Abstract Background repABC operons are present on large, low copy-number plasmids and on some secondary chromosomes in at least 19 α-proteobacterial genera, and are responsible for the replication and segregation properties of these replicons. These operons consist, with some variations, of three genes: repA, repB, and repC. RepA and RepB are involved in plasmid partitioning and in the negative regulation of their own transcription, and RepC is the limiting factor for replication. An antisense RNA encoded between the repB-repC genes modulates repC expression. Results To identify the minimal region of the Rhizobium etli p42d plasmid that is capable of autonomous replication, we amplified different regions of the repABC operon using PCR and cloned the regions into a suicide vector. The resulting vectors were then introduced into R. etli strains that did or did not contain p42d. The minimal replicon consisted of a repC open reading frame under the control of a constitutive promoter with a Shine-Dalgarno sequence that we designed. A sequence analysis of repC revealed the presence of a large A+T-rich region but no iterons or DnaA boxes. Silent mutations that modified the A+T content of this region eliminated the replication capability of the plasmid. The minimal replicon could not be introduced into R. etli strain containing p42d, but similar constructs that carried repC from Sinorhizobium meliloti pSymA or the linear chromosome of Agrobacterium tumefaciens replicated in the presence or absence of p42d, indicating that RepC is an incompatibility factor. A hybrid gene construct expressing a RepC protein with the first 362 amino acid residues from p42d RepC and the last 39 amino acid residues of RepC from SymA was able to replicate in the presence of p42d. Conclusions RepC is the only element encoded in the repABC operon of the R. etli p42d plasmid that is necessary and sufficient for plasmid replication and is probably the initiator protein. The ori

  7. A defective ABC transporter of the MRP family, responsible for the bean lpa1 mutation, affects the regulation of the phytic acid pathway, reduces seed myo-inositol and alters ABA sensitivity.

    Science.gov (United States)

    Panzeri, Dario; Cassani, Elena; Doria, Enrico; Tagliabue, Giovanni; Forti, Luca; Campion, Bruno; Bollini, Roberto; Brearley, Charles A; Pilu, Roberto; Nielsen, Erik; Sparvoli, Francesca

    2011-07-01

    • We previously identified the lpa1 (low phytic acid) 280-10 line that carries a mutation conferring a 90% reduction in phytic acid (InsP(6) ) content. In contrast to other lpa mutants, lpa1(280-10) does not display negative pleiotropic effects. In the present paper, we have identified the mutated gene and analysed its impact on the phytic acid pathway. • Here, we mapped the lpa1(280-10) mutation by bulk analysis on a segregating F(2) population, an then, by comparison with the soybean genome, we identified and sequenced a candidate gene. The InsP(6) pathway was analysed by gene expression and quantification of metabolites. • The mutated Pvmrp1(280-10) cosegregates with the lpa1(280-10) mutation, and the expression level of several genes of the InsP(6) pathway are reduced in the lpa1(280-10) mutant as well as the inositol and raffinosaccharide content. PvMrp2, a very similar paralogue of PvMrp1 was also mapped and sequenced. • The lpa1 mutation in beans is likely the result of a defective Mrp1 gene (orthologous to the lpa genes AtMRP5 and ZmMRP4), while its Mrp2 paralog is not able to complement the mutant phenotype in the seed. This mutation appears to down-regulate the InsP(6) pathway at the transcriptional level, as well as altering inositol-related metabolism and affecting ABA sensitivity.

  8. Genetic variation in the proximal promoter of ABC and SLC superfamilies: liver and kidney specific expression and promoter activity predict variation.

    Directory of Open Access Journals (Sweden)

    Stephanie E Hesselson

    Full Text Available Membrane transporters play crucial roles in the cellular uptake and efflux of an array of small molecules including nutrients, environmental toxins, and many clinically used drugs. We hypothesized that common genetic variation in the proximal promoter regions of transporter genes contribute to observed variation in drug response. A total of 579 polymorphisms were identified in the proximal promoters (-250 to +50 bp and flanking 5' sequence of 107 transporters in the ATP Binding Cassette (ABC and Solute Carrier (SLC superfamilies in 272 DNA samples from ethnically diverse populations. Many transporter promoters contained multiple common polymorphisms. Using a sliding window analysis, we observed that, on average, nucleotide diversity (pi was lowest at approximately 300 bp upstream of the transcription start site, suggesting that this region may harbor important functional elements. The proximal promoters of transporters that were highly expressed in the liver had greater nucleotide diversity than those that were highly expressed in the kidney consistent with greater negative selective pressure on the promoters of kidney transporters. Twenty-one promoters were evaluated for activity using reporter assays. Greater nucleotide diversity was observed in promoters with strong activity compared to promoters with weak activity, suggesting that weak promoters are under more negative selective pressure than promoters with high activity. Collectively, these results suggest that the proximal promoter region of membrane transporters is rich in variation and that variants in these regions may play a role in interindividual variation in drug disposition and response.

  9. Fasting activates the gene expression of UCP3 independent of genes necessary for lipid transport and oxidation in skeletal muscle.

    Science.gov (United States)

    Tunstall, Rebecca J; Mehan, Kate A; Hargreaves, Mark; Spriet, Lawrence L; Cameron-Smith, David

    2002-06-07

    Fasting triggers a complex array of adaptive metabolic and hormonal responses including an augmentation in the capacity for mitochondrial fatty acid (FA) oxidation in skeletal muscle. This study hypothesized that this adaptive response is mediated by increased mRNA of key genes central to the regulation of fat oxidation in human skeletal muscle. Fasting dramatically increased UCP3 gene expression, by 5-fold at 15 h and 10-fold at 40 h. However the expression of key genes responsible for the uptake, transport, oxidation, and re-esterification of FA remained unchanged following 15 and 40 h of fasting. Likewise there was no change in the mRNA abundance of transcription factors. This suggests a unique role for UCP3 in the regulation of FA homeostasis during fasting as adaptation to 40 h of fasting does not require alterations in the expression of other genes necessary for lipid metabolism.

  10. The effect of transport stress on turkey (Meleagris gallopavo) liver acute phase proteins gene expression.

    Science.gov (United States)

    Marques, Andreia Tomás; Lecchi, Cristina; Grilli, Guido; Giudice, Chiara; Nodari, Sara Rota; Vinco, Leonardo J; Ceciliani, Fabrizio

    2016-02-01

    The aim of this study was to investigate the effects of transport-related stress on the liver gene expression of four acute phase proteins (APP), namely α1-acid glycoprotein (AGP), C-Reactive Protein (CRP), Serum Amyloid A (SAA) and PIT54, in turkeys (Meleagris gallopavo). A group of seven BUT BIG 6 commercial hens was subjected to a two-hour long road transportation and the quantitative gene expression of APP in the liver was compared to that of a non transported control group. The expression of AGP and CRP mRNA was found to be increased in animals slaughtered after road transport. The presence of AGP protein was also confirmed by immunohistochemistry and Western blotting. The results of this study showed that road-transport may induce the mRNA expression of immune related proteins. The finding that AGP and CRP can be upregulated during transport could suggest their use as for the assessment of turkey welfare during transport.

  11. Targetable activating mutations are very frequent in GCB and ABC diffuse large B-cell lymphoma.

    Science.gov (United States)

    Bohers, Elodie; Mareschal, Sylvain; Bouzelfen, Abdelilah; Marchand, Vinciane; Ruminy, Philippe; Maingonnat, Catherine; Ménard, Anne-Lise; Etancelin, Pascaline; Bertrand, Philippe; Dubois, Sydney; Alcantara, Marion; Bastard, Christian; Tilly, Hervé; Jardin, Fabrice

    2014-02-01

    Diffuse large B cell lymphoma (DLBCL) is an aggressive and heterogeneous malignancy that can be divided in two major subgroups, germinal center B-cell-like (GCB) and activated B-cell-like (ABC). Activating mutations of genes involved in the BCR and NF-κB pathways (CD79A, CD79B, MYD88, and CARD11) or in epigenetic regulation (EZH2) have been recently reported, preferentially in one of the two DLBCL subtypes. We analyzed the mutational status of these five recurrently mutated genes in a cohort of 161 untreated de novo DLBCL. Overall, 93 mutations were detected, in 61 (38%) of the patients. The L265P MYD88 mutation was the most frequent MYD88 variant (n = 18), observed exclusively in the ABC subtype. CD79A/CD79B ITAM domains were targeted in ABC DLBCL (12/77; 16%), whereas CARD11 mutations were equally distributed in the two subtypes. The EZH2 Y641 substitution was found almost exclusively in the GCB subgroup (15/62; 24%). Twenty cases (12%) displayed two activating mutations, including the most frequent CD79/MYD88 variants combination (n = 8) which is observed exclusively in the ABC subtype. When considering only ABC DLBCL patients treated by rituximab plus chemotherapy, the presence of an activating NF-κB mutation was associated with an unfavorable outcome (3-years OS 26% for mutated cases versus 67% for the cases without mutations, P = 0.0337). Our study demonstrates that activating and targetable mutations are observed at a very high frequency in DLBCL at the time of diagnosis, indicating that sequencing of a limited number of genes could help tailor an optimal treatment strategy in DLBCL.

  12. Application of Time and Distance Driven ABC in Truck-load Transport Costing%时间和距离驱动作业成本法在整车运输成本核算中的应用

    Institute of Scientific and Technical Information of China (English)

    张庆平; 向吉美; 师建华

    2011-01-01

    提出应用时间和距离作业成本法核算单次整车运输任务成本,并给出了合算步骤,最后通过具体的运输任务实例说明了计算整车运输成本的过程,证明该方法简捷并具有可操作业.%The paper proposes to use time and distance driven activity-based costing in accounting the cost of a single operation of truck-load transportation and prese nts an empirical example for illustration.

  13. Gene-Gene-Environment Interactions of Serotonin Transporter, Monoamine Oxidase A and Childhood Maltreatment Predict Aggressive Behavior in Chinese Adolescents

    Science.gov (United States)

    Zhang, Yun; Ming, Qing-sen; Yi, Jin-yao; Wang, Xiang; Chai, Qiao-lian; Yao, Shu-qiao

    2017-01-01

    Gene-environment interactions that moderate aggressive behavior have been identified independently in the serotonin transporter (5-HTT) gene and monoamine oxidase A gene (MAOA). The aim of the present study was to investigate epistasis interactions between MAOA-variable number tandem repeat (VNTR), 5-HTTlinked polymorphism (LPR) and child abuse and the effects of these on aggressive tendencies in a group of otherwise healthy adolescents. A group of 546 Chinese male adolescents completed the Child Trauma Questionnaire and Youth self-report of the Child Behavior Checklist. Buccal cells were collected for DNA analysis. The effects of childhood abuse, MAOA-VNTR, 5-HTTLPR genotypes and their interactive gene-gene-environmental effects on aggressive behavior were analyzed using a linear regression model. The effect of child maltreatment was significant, and a three-way interaction among MAOA-VNTR, 5-HTTLPR and sexual abuse (SA) relating to aggressive behaviors was identified. Chinese male adolescents with high expression of the MAOA-VNTR allele and 5-HTTLPR “SS” genotype exhibited the highest aggression tendencies with an increase in SA during childhood. The findings reported support aggression being a complex behavior involving the synergistic effects of gene-gene-environment interactions. PMID:28203149

  14. Linking the serotonin transporter gene, family environments, hippocampal volume and depression onset: A prospective imaging gene × environment analysis.

    Science.gov (United States)

    Little, Keriann; Olsson, Craig A; Youssef, George J; Whittle, Sarah; Simmons, Julian G; Yücel, Murat; Sheeber, Lisa B; Foley, Debra L; Allen, Nicholas B

    2015-11-01

    A single imaging gene-environment (IGxE) framework that is able to simultaneously model genetic, neurobiological, and environmental influences on psychopathology outcomes is needed to improve understanding of how complex interrelationships between allelic variation, differences in neuroanatomy or neuroactivity, and environmental experience affect risk for psychiatric disorder. In a longitudinal study of adolescent development we demonstrate the utility of such an IGxE framework by testing whether variation in parental behavior at age 12 altered the strength of an imaging genetics pathway, involving an indirect association between allelic variation in the serotonin transporter gene to variation in hippocampal volume and consequent onset of major depressive disorder by age 18. Results were consistent with the presence of an indirect effect of the serotonin transporter S-allele on depression onset via smaller left and right hippocampal volumes that was significant only in family environments involving either higher levels of parental aggression or lower levels of positive parenting. The previously reported finding of S-allele carriers' increased risk of depression in adverse environments may, therefore, be partly because of the effects of these environments on a neurobiological pathway from the serotonin transporter gene to depression onset that proceeds through variation in hippocampal volume.

  15. Common Genetic Variation In Cellular Transport Genes and Epithelial Ovarian Cancer (EOC) Risk

    NARCIS (Netherlands)

    Chornokur, G.; Lin, H.Y.; Tyrer, J.P.; Lawrenson, K.; Dennis, J.; Amankwah, E.K.; Qu, X.; Tsai, Y.Y.; Jim, H.S.; Chen, Z.; Chen, A.Y.; Permuth-Wey, J.; Aben, K.; Anton-Culver, H.; Antonenkova, N.; Bruinsma, F.; Bandera, E.V.; Bean, Y.T.; Beckmann, M.W.; Bisogna, M.; Bjorge, L.; Bogdanova, N.; Brinton, L.A.; Brooks-Wilson, A.; Bunker, C.H.; Butzow, R.; Campbell, I.G.; Carty, K.; Chang-Claude, J.; Cook, L.S.; Cramer, D.W; Cunningham, J.M.; Cybulski, C.; Dansonka-Mieszkowska, A.; Bois, A. du; Despierre, E.; Dicks, E.; Doherty, J.A.; Dork, T.; Durst, M.; Easton, D.F.; Eccles, D.M.; Edwards, R.P.; Ekici, A.B.; Fasching, P.A.; Fridley, B.L.; Gao, Y.T.; Gentry-Maharaj, A.; Giles, G.G.; Glasspool, R.; Goodman, M.T.; Gronwald, J.; Harrington, P.; Harter, P.; Hein, A.; Heitz, F.; Hildebrandt, M.A.T.; Hillemanns, P.; Hogdall, C.K.; Hogdall, E.; Hosono, S.; Jakubowska, A.; Jensen, A.; Ji, B.T.; Karlan, B.Y.; Kelemen, L.E.; Kellar, M.; Kiemeney, L.A.L.M.; Krakstad, C.; Kjaer, S.K.; Kupryjanczyk, J.; Lambrechts, D.; Lambrechts, S.; Le, N.D.; Lee, A.W.; Lele, S.; Leminen, A.; Lester, J.; Levine, D.A.; Liang, D.; Lim, B.K.; Lissowska, J.; Lu, K.; Lubinski, J.; Lundvall, L.; Massuger, L.F.A.G.; Matsuo, K.; McGuire, V.; McLaughlin, J.R.; McNeish, I.; Menon, U.; Milne, R.L.; Modugno, F.; Moysich, K.B.; Ness, R.B.; Nevanlinna, H.; Eilber, U.; Odunsi, K.; Olson, S.H.; Orlow, I., et al.

    2015-01-01

    BACKGROUND: Defective cellular transport processes can lead to aberrant accumulation of trace elements, iron, small molecules and hormones in the cell, which in turn may promote the formation of reactive oxygen species, promoting DNA damage and aberrant expression of key regulatory cancer genes. As

  16. Recognition of Scared Faces and the Serotonin Transporter Gene in Young Children: The Generation R Study

    Science.gov (United States)

    Szekely, Eszter; Herba, Catherine M.; Arp, Pascal P.; Uitterlinden, Andre G.; Jaddoe, Vincent W. V.; Hofman, Albert; Verhulst, Frank C.; Hudziak, James J.; Tiemeier, Henning

    2011-01-01

    Background: Previous research highlights the significance of a functional polymorphism located in the promoter region (5-HTTLPR) of the serotonin transporter gene in emotional behaviour. This study examined the effect of the 5-HTTLPR polymorphism on emotion processing in a large number of healthy preschoolers. Methods: The 5-HTTLPR genotype was…

  17. Common Genetic Variation In Cellular Transport Genes and Epithelial Ovarian Cancer (EOC) Risk

    DEFF Research Database (Denmark)

    Chornokur, Ganna; Lin, Hui-Yi; Tyrer, Jonathan P

    2015-01-01

    BACKGROUND: Defective cellular transport processes can lead to aberrant accumulation of trace elements, iron, small molecules and hormones in the cell, which in turn may promote the formation of reactive oxygen species, promoting DNA damage and aberrant expression of key regulatory cancer genes. ...

  18. Clinical Efficacy of Fluvoxamine and Functional Polymorphism in a Serotonin Transporter Gene on Childhood Autism

    Science.gov (United States)

    Sugie, Yoko; Sugie, Hideo; Fukuda,Tokiko; Ito, Masataka; Sasada, Yumiko; Nakabayashi, Mutsumi; Fukashiro, Kazunobu; Ohzeki, Takehiko

    2005-01-01

    We studied the correlation between response to fluvoxamine and serotonin transporter gene promoter region polymorphism (5-HTTLPR). Eighteen children with autistic disorder completed a 12-week double-blind, placebo-controlled, randomized crossover study of fluvoxamine. Behavioral assessments were obtained before and at 12 weeks of treatment.…

  19. Functional analysis of a novel human serotonin transporter gene promoter in immortalized raphe cells

    DEFF Research Database (Denmark)

    Mortensen, O V; Thomassen, M; Larsen, M B;

    1999-01-01

    To investigate the structural basis for genetic regulation of the human serotonin transporter gene, a 1.8 kb fragment upstream to the cap site was cloned and sequenced. The promoter possesses a polymorphic repeat region with 16 and 14 repeats, respectively. Both were cloned and characterized. The...

  20. MANFAAT DATA WAREHOUSE PADA PT ABC

    Directory of Open Access Journals (Sweden)

    Evaristus Didik Madyatmadja

    2013-11-01

    Full Text Available The purpose of this paper is to analyze the current system to find out problems faced by the company and propose alternative solutions and generate information needed by management by designing a data warehouse according to the information needs of PT ABC. This research implements analysis and design of data warehouse by Ralph Kimball and Ross cited by Connolly and Begg, known as Nine-Step Methodology. The result obtained is a data warehouse application that may present a multidimensional historical data that can assist the management in decisions. Designing data warehouse at PT ABC makes concise the enterprise data and can be viewed from several dimensions. It helps users analyze data for strategic decision quickly and accurately.

  1. Gene : CBRC-EEUR-01-1548 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available permease protein, ABC-type branched chain amino acid transporter transporter [Aurantimonas sp. SI85-9A1] gb...|EAS51222.1| putative permease protein, ABC-type branched chain amino acid transporter transporter [Aurantim

  2. ABC of physics a very brief guide

    CERN Document Server

    Okun, Lev Borisovich

    2012-01-01

    This little book concentrates on the foundations of modern physics (its "ABC's") and its most fundamental constants: c - the velocity of light and ? - the quantum of action. First of all, the book is addressed to professional physicists, but in order to achieve maximal concentration and clarity it uses the simplest (high school) mathematics. As a result many pages of the book will be useful to college students and may appeal to a more general audience.

  3. The ABC transporter ABC40 encodes a phenylacetic acid export system in Penicillium chrysogenum

    NARCIS (Netherlands)

    Weber, Stefan S.; Kovalchuk, Andriy; Bovenberg, Roe A. L.; Driessen, Arnold J. M.

    2012-01-01

    The filamentous fungus Penicillium chrysogenum is used for the industrial production of beta-lactam antibiotics. The pathway for beta-lactam biosynthesis has been resolved and involves the enzyme phenylacetic acid CoA ligase that is responsible for the CoA activation of the side chain precursor phen

  4. The ABC of ABC-transport in the hyperthermophilic archaeon Pyrococcus furiosus

    OpenAIRE

    Koning, S.

    2003-01-01

    Living organisms of our earth can be divided into two groups, the prokaryotes and the eukaryotes. Eukaryotic cells have a nucleus, a special compartment in the cell, where the genetic material, the DNA is located. The DNA in the prokaryotic cell is floating freely in the cell. The eukaryotes, that is where we belong to, together with animals, plants and fungi. Bacteria and archaea belong to the prokaryotes. Archaea resemble bacteria but in certain features they resemble more the eukaryotes. T...

  5. The ABC of ABC-transport in the hyperthermophilic archaeon Pyrococcus furiosus

    NARCIS (Netherlands)

    Koning, S

    2003-01-01

    Living organisms of our earth can be divided into two groups, the prokaryotes and the eukaryotes. Eukaryotic cells have a nucleus, a special compartment in the cell, where the genetic material, the DNA is located. The DNA in the prokaryotic cell is floating freely in the cell. The eukaryotes, that i

  6. OsHT, a Rice Gene Encoding for a Plasma-Membrane Localized Histidine Transporter

    Institute of Scientific and Technical Information of China (English)

    Di LIU; Wei GONG; Yong BAI; Jing-Chu LUO; Yu-Xian ZHU

    2005-01-01

    Using a degenerative probe designed according to the most conservative region of a known Lys- and His-specific amino acid transporter (LHT1) from Arabidopsis, we isolated a full-length cDNA named OsHT (histidine transporter of Oryza sativa L.) by screening the rice cDNA library. The cDNA is 1.3kb in length and the open reading frame encodes for a 441 amino acid protein with a calculated molecular mass of 49 kDa. Multiple sequence alignments showed that OsHT shares a high degree of sequence conservation at the deduced amino acid level with the Arabidopsis LHT1 and six putative lysine and histidine transporters. Computational analysis indicated that OsHT is an integral membrane protein with 11 putative transmembrane helices. This was confirmed by the transient expression assay because the OsHT-GFP fusion protein was, indeed, localized mainly in the plasma membrane of onion epidermal cells. Functional complementation experiments demonstrated that OsHT was able to work as a histidine transporter in Saccharomyces cerevisiae, suggesting that OsHT is a gene that encodes for a histidine transporter from rice.This is the first time that an LHT-type amino acid transporter gene has been cloned from higher plants other than A rabidopsis.

  7. Impact of lux gene insertion on bacterial surface properties and transport.

    Science.gov (United States)

    Chen, Gang; Srinivasa Ranga, Vijay Penagonda; Mao, Yongjun; Chen, Kevin; Qiao, Hanzi

    2008-03-01

    Genetic markers have been in popular use for tracing microbial movement in the environment. However, the impact of genetic marker insertion on microbial surface properties and consequent transport is often ignored. For this research, we investigated the impact of luminescence-based genetic marker insertion on bacterial surface properties and transport. Typical Gram-positive bacterial strains of Lactobacillus casei, Streptococcus mitis and Micrococcus luteus were used as model bacterial strains in this research. We manipulated gene transfer to observe the impact of lux gene insertion on bacterial surface properties based on contact angle measurements, and we conducted column experiments to evaluate the impact of lux gene insertion on bacterial transport. After lux gene insertion, bacterial interactions with the porous media increased, demonstrating stronger deposition potential in the porous media. Accordingly, retention of the daughter strains increased. Lux gene insertion also resulted in an increase in bacterial dispersion and equilibrium adsorption in the porous media. The bacterial deposition coefficient was found to correlate with the free energy of interactions between bacteria and the porous media.

  8. Conformational plasticity of the type I maltose ABC importer.

    Science.gov (United States)

    Böhm, Simon; Licht, Anke; Wuttge, Steven; Schneider, Erwin; Bordignon, Enrica

    2013-04-01

    ATP-binding cassette (ABC) transporters couple the translocation of solutes across membranes to ATP hydrolysis. Crystal structures of the Escherichia coli maltose importer (MalFGK2) in complex with its substrate binding protein (MalE) provided unprecedented insights in the mechanism of substrate translocation, leaving the MalE-transporter interactions still poorly understood. Using pulsed EPR and cross-linking methods we investigated the effects of maltose and MalE on complex formation and correlated motions of the MalK2 nucleotide-binding domains (NBDs). We found that both substrate-free (open) and liganded (closed) MalE interact with the transporter with similar affinity in all nucleotide states. In the apo-state, binding of open MalE occurs via the N-lobe, leaving the C-lobe disordered, but upon maltose binding, closed MalE associates tighter to the transporter. In both cases the NBDs remain open. In the presence of ATP, the transporter binds both substrate-free and liganded MalE, both inducing the outward-facing conformation trapped in the crystal with open MalE at the periplasmic side and NBDs tightly closed. In contrast to ATP, ADP-Mg(2+) alone is sufficient to induce a semiopen conformation in the NBDs. In this nucleotide-driven state, the transporter binds both open and closed MalE with slightly different periplasmic configurations. We also found that dissociation of MalE is not a required step for substrate translocation since a supercomplex with MalE cross-linked to MalG retains the ability to hydrolyze ATP and to transport maltose. These features of MalE-MalFGK2 interactions highlight the conformational plasticity of the maltose importer, providing insights into the ATPase stimulation by unliganded MalE.

  9. Divergent Evolutionary Pattern of Sugar Transporter Genes is Associated with the Difference in Sugar Accumulation between Grasses and Eudicots.

    Science.gov (United States)

    Wang, Wei; Zhou, Hui; Ma, Baiquan; Owiti, Albert; Korban, Schuyler S; Han, Yuepeng

    2016-06-30

    Sugars play a variety of roles in plants, and their accumulation in seeds and/or surrounding pericarp tissues is distinctly different between grasses and eudicots. However, little is known about the evolutionary pattern of genes involved in sugar accumulation in these two major groups of flowering plants. Here, we compared evolutionary rates, gene duplication, and selective patterns of genes involved in sugar metabolism and transport between grasses and eudicots using six grass species and seven eudicot species as materials. Overall, sugar transporter genes exhibit divergent evolutionary patterns, whereas, sugar metabolism genes showing similar evolutionary pattern between monocots and eudicots. Sugar transporter genes have higher frequencies of recent duplication in eudicots than in grasses and their patterns of evolutionary rate are different. Evidence for divergent selection of these two groups of flowering plants is also observed in sugar transporter genes, wherein, these genes have undergone positive selection in eudicots, but not in grasses. Taken together, these findings suggest that sugar transporter genes rather than sugar metabolism genes play important roles in sugar accumulation in plants, and that divergent evolutionary patterns of sugar transporter genes are associated with the difference of sugar accumulation in storage tissues of grasses and eudicots.

  10. Fast correlation attack on stream cipher ABC v3

    Institute of Scientific and Technical Information of China (English)

    ZHANG HaiNa; LI Lin; WANG XiaoYun

    2008-01-01

    ABC v3 is a stream cipher submitted to the ECRYPT eStream project and has entered the second evaluation phase.Its key length is 128 bits.In this paper,we find large numbers of new weak keys of ABC family and introduce a method to search for them,and then apply a fast correlation attack to break ABC v3 with weak keys.We show that there are at least 2103.71 new weak keys in ABC v3.Recovering the internal state of a weak key requires 236.05 keystream words and 250.56 operations.The attack can be applied to ABC v1 and v2 with the same complexity as that of ABC v3.However,the number of weak keys of ABC v1 as well as ABC v2 decreases to 297+295.19.It reveals that ABC v3 incurs more weak keys than that of ABC v1 and v2.

  11. The Creatine Transporter Gene Paralogous at 16p11.2 Is Expressed in Human Brain

    Directory of Open Access Journals (Sweden)

    Nadia Bayou

    2008-01-01

    We report on the clinical, cytogenetic, and molecular findings in a boy with autism carrying a de novo translocation t(7;16(p22.1;p11.2. The chromosome 16 breakpoint disrupts the paralogous SLC6A8 gene also called SLC6A10 or CT2. Predicted translation of exons and RT-PCR analysis reveal specific expression of the creatine transporter paralogous in testis and brain. Several studies reported on the role of X-linked creatine transporter mutations in individuals with mental retardation, with or without autism. The existence of disruption in SLC6A8 paralogous gene associated with idiopathic autism suggests that this gene may be involved in the autistic phenotype in our patient.

  12. Cloning, Sequencing and Functional Testing of the DNA Fragment Containing nodABC Genes of Rhizobium hainanense%海南根瘤菌nodABC基因DNA片段的克隆、测序和功能验证

    Institute of Scientific and Technical Information of China (English)

    温尚昆; 李小红; 王磊; 杨苏声

    2003-01-01

    从海南根瘤菌(Rhizobium hainanense)I66提取总DNA,用EcoR I酶进行完全酶切和电泳,然后用苜蓿中华根瘤菌(Sinorhizobium meliloti)042B的nodABC DNA片段作探针进行Southern杂交,发现1条含有nodABC基因DNA片段的阳性条带,大小为2.1~2.5kb.通过电泳回收该DNA片段,用pUC18作载体连接,并转化大肠杆菌(Escherichia coli)DH5 α,从而构建了含有nodABC的部分基因文库.提取该文库的质粒与nodABC探针做菌落杂交,筛选到nodABC的阳性克隆,称为pUER12.将含有nodABC的DNA片段与EcoR Ⅰ酶切的pBBR-MCS-5连接,转化大肠杆菌DH5 α,获得转化子pBER12.用三亲本杂交方法,把pBER12转入苜蓿中华根瘤菌AK1657,将其接合子进行结瘤实验,验证了pBER12具有nodABC基因的功能.然后将含有I66 nodABC片段的DNA与EcoRⅠ酶切的pGEM-7Z(+)连接、测序和进行同源性比较,发现I66 nodABC编码的蛋白与苜蓿中华根瘤菌具有高度的同源性.

  13. Transcriptional regulation of the cydDC operon, encoding a heterodimeric ABC transporter required for assembly of cytochromes c and bd in Escherichia coli K-12: regulation by oxygen and alternative electron acceptors.

    Science.gov (United States)

    Cook, G M; Membrillo-Hernández, J; Poole, R K

    1997-01-01

    The expression of the cydDC operon was investigated by using a chromosomal phi(cydD-lacZ) transcriptional fusion and primer extension analysis. A single transcriptional start site was found for cydD located 68 bp upstream of the translational start site, and Northern blot analysis confirmed that cydDC is transcribed as a polycistronic message independently of the upstream gene trxB. cydDC was highly expressed under aerobic growth conditions and during anaerobic growth with alternative electron acceptors. Aerobic expression was independent of ArcA and Fnr, but induction of cydDC by nitrate and nitrite was dependent on NarL and Fnr. PMID:9335308

  14. Regulatory pathways for ATP-binding cassette transport proteins in kidney proximal tubules

    NARCIS (Netherlands)

    Masereeuw, R.; Russel, F.G.M.

    2012-01-01

    The ATP-binding cassette transport proteins (ABC transporters) represent important determinants of drug excretion. Protective or excretory tissues where these transporters mediate substrate efflux include the kidney proximal tubule. Regulation of the transport proteins in this tissue requires elabor

  15. The alteration of zinc transporter gene expression is associated with inflammatory markers in obese women.

    Science.gov (United States)

    Noh, Hwayoung; Paik, Hee Young; Kim, Jihye; Chung, Jayong

    2014-04-01

    Obesity, a chronic inflammatory state, is associated with altered zinc metabolism. ZnT and Zip transporters are involved in the regulation of zinc metabolism. This study examined the relationships among obesity, zinc transporter gene expression, and inflammatory markers in young Korean women. The messenger RNA (mRNA) levels of leukocyte zinc transporters between obese (BMI = 28.3 ± 0.5 kg/m(2), n = 35) and nonobese (BMI = 20.7 ± 0.2 kg/m(2), n = 20) women aged 18-28 years were examined using quantitative real-time polymerase chain reaction. Inflammatory markers, such as C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), and interleukin (IL)-6, were measured in serum by enzyme immunoassay. ZnT1 and Zip1 were the most abundantly expressed zinc transporters in leukocytes. The mRNA levels of many zinc transporters (ZnT4, ZnT5, ZnT9, Zip1, Zip4, and Zip6) were significantly lower in obese women, and expression of these genes was inversely correlated with BMI and body fat percentage. In addition, inflammatory markers (CRP and TNF-α) were significantly higher in obese women. The mRNA levels of ZnT4, Zip1, and Zip6 were inversely correlated with CRP (P zinc transporters such as ZnT4, ZnT5, Zip1, and Zip6 (P zinc transporters may be altered in obese individuals. Changes in zinc transporters may also be related to the inflammatory state associated with obesity.

  16. Molecular evolutionary analysis of ABCB5: the ancestral gene is a full transporter with potentially deleterious single nucleotide polymorphisms.

    Directory of Open Access Journals (Sweden)

    Karobi Moitra

    Full Text Available BACKGROUND: ABCB5 is a member of the ABC protein superfamily, which includes the transporters ABCB1, ABCC1 and ABCG2 responsible for causing drug resistance in cancer patients and also several other transporters that have been linked to human disease. The ABCB5 full transporter (ABCB5.ts is expressed in human testis and its functional significance is presently unknown. Another variant of this transporter, ABCB5 beta possess a "half-transporter-like" structure and is expressed in melanoma stem cells, normal melanocytes, and other types of pigment cells. ABCB5 beta has important clinical implications, as it may be involved with multidrug resistance in melanoma stem cells, allowing these stem cells to survive chemotherapeutic regimes. METHODOLOGY/PRINCIPAL FINDINGS: We constructed and examined in detail topological structures of the human ABCB5 protein and determined in-silico the cSNPs (coding single nucleotide polymorphisms that may affect its function. Evolutionary analysis of ABCB5 indicated that ABCB5, ABCB1, ABCB4, and ABCB11 share a common ancestor, which began duplicating early in the evolutionary history of chordates. This suggests that ABCB5 has evolved as a full transporter throughout its evolutionary history. CONCLUSIONS/SIGNIFICANCE: From our in-silco analysis of cSNPs we found that a large number of non-synonymous cSNPs map to important functional regions of the protein suggesting that these SNPs if present in human populations may play a role in diseases associated with ABCB5. From phylogenetic analyses, we have shown that ABCB5 evolved as a full transporter throughout its evolutionary history with an absence of any major shifts in selection between the various lineages suggesting that the function of ABCB5 has been maintained during mammalian evolution. This finding would suggest that ABCB5 beta may have evolved to play a specific role in human pigment cells and/or melanoma cells where it is predominantly expressed.

  17. Emotional modulation of muscle pain is associated with polymorphisms in the serotonin transporter gene.

    Science.gov (United States)

    Horjales-Araujo, Emilia; Demontis, Ditte; Lund, Ellen Kielland; Vase, Lene; Finnerup, Nanna Brix; Børglum, Anders D; Jensen, Troels Staehelin; Svensson, Peter

    2013-08-01

    The perception of pain is determined by a combination of genetic, neurobiological, cultural, and emotional factors. Recent studies have demonstrated an association between specific genotypes and pain perception. Particular focus has been given to the triallelic polymorphism in the promoter region of the serotonin transporter gene in relation to pain perception. The aim of this study was to investigate whether the modulatory effect of emotions mediated by visual stimuli on muscular pain perception is genotype dependent. A total of 150 healthy subjects were selected on the basis of their polymorphism in the serotonin transporter gene. First, visual conditioning was performed with positive, negative, and neutral pictures from the International Affective Picture System, and the unpleasantness/pleasantness of the pictures was rated. Second, visual conditioning stimuli were presented while experimental jaw muscle pain was evoked by injection of hypertonic saline into the masseter muscle, and participants continuously rated pain intensity on an electronic visual analogue scale. The pictures induced similar changes in emotions across the 3 genotype groups, and hypertonic saline evoked moderate pain levels in all participants. However, in participants with a high expression of the serotonin transporter protein, conditioning with negative pictures increased pain intensity and positive pictures decreased pain intensity when compared with neutral pictures. In contrast, there were no significant effects of the pictures on pain perception in participants with either intermediate or low expression of the protein. These results suggest that polymorphisms in the serotonin transporter gene play an important role in emotions modulation of muscle pain.

  18. Soil inoculation with symbiotic microorganisms promotes plant growth and nutrient transporter genes expression in durum wheat.

    Science.gov (United States)

    Saia, Sergio; Rappa, Vito; Ruisi, Paolo; Abenavoli, Maria Rosa; Sunseri, Francesco; Giambalvo, Dario; Frenda, Alfonso S; Martinelli, Federico

    2015-01-01

    In a field experiment conducted in a Mediterranean area of inner Sicily, durum wheat was inoculated with plant growth-promoting rhizobacteria (PGPR), with arbuscular mycorrhizal fungi (AMF), or with both to evaluate their effects on nutrient uptake, plant growth, and the expression of key transporter genes involved in nitrogen (N) and phosphorus (P) uptake. These biotic associations were studied under either low N availability (unfertilized plots) and supplying the soil with an easily mineralizable organic fertilizer. Regardless of N fertilization, at the tillering stage, inoculation with AMF alone or in combination with PGPR increased the aboveground biomass yield compared to the uninoculated control. Inoculation with PGPR enhanced the aboveground biomass yield compared to the control, but only when N fertilizer was added. At the heading stage, inoculation with all microorganisms increased the aboveground biomass and N. Inoculation with PGPR and AMF+PGPR resulted in significantly higher aboveground P compared to the control and inoculation with AMF only when organic N was applied. The role of microbe inoculation in N uptake was elucidated by the expression of nitrate transporter genes. NRT1.1, NRT2, and NAR2.2 were significantly upregulated by inoculation with AMF and AMF+PGPR in the absence of organic N. A significant down-regulation of the same genes was observed when organic N was added. The ammonium (NH4 (+)) transporter genes AMT1.2 showed an expression pattern similar to that of the NO3 (-) transporters. Finally, in the absence of organic N, the transcript abundance of P transporters Pht1 and PT2-1 was increased by inoculation with AMF+PGPR, and inoculation with AMF upregulated Pht2 compared to the uninoculated control. These results indicate the soil inoculation with AMF and PGPR (alone or in combination) as a valuable option for farmers to improve yield, nutrient uptake, and the sustainability of the agro-ecosystem.

  19. Child dopamine active transporter 1 genotype and parenting: evidence for evocative gene-environment correlations.

    Science.gov (United States)

    Hayden, Elizabeth P; Hanna, Brigitte; Sheikh, Haroon I; Laptook, Rebecca S; Kim, Jiyon; Singh, Shiva M; Klein, Daniel N

    2013-02-01

    The dopamine active transporter 1 (DAT1) gene is implicated in psychopathology risk. Although the processes by which this gene exerts its effects on risk are poorly understood, a small body of research suggests that the DAT1 gene influences early emerging negative emotionality, a marker of children's psychopathology risk. As child negative emotionality evokes negative parenting practices, the DAT1 gene may also play a role in gene-environment correlations. To test this model, children (N = 365) were genotyped for the DAT1 gene and participated in standardized parent-child interaction tasks with their primary caregiver. The DAT1 gene 9-repeat variant was associated with child negative affect expressed toward the parent during parent-child interactions, and parents of children with a 9-repeat allele exhibited more hostility and lower guidance/engagement than parents of children without a 9-repeat allele. These gene-environment associations were partially mediated by child negative affect toward the parent. The findings implicate a specific polymorphism in eliciting negative parenting, suggesting that evocative associations play a role in elevating children's risk for emotional trajectories toward psychopathology risk.

  20. The Acinetobacter baumannii Two-Component System AdeRS Regulates Genes Required for Multidrug Efflux, Biofilm Formation, and Virulence in a Strain-Specific Manner

    Directory of Open Access Journals (Sweden)

    Grace E. Richmond

    2016-04-01

    Full Text Available The opportunistic pathogen Acinetobacter baumannii is able to persist in the environment and is often multidrug resistant (MDR, causing difficulties in the treatment of infections. Here, we show that the two-component system AdeRS, which regulates the production of the AdeABC multidrug resistance efflux pump, is required for the formation of a protective biofilm in an ex vivo porcine mucosal model, which mimics a natural infection of the human epithelium. Interestingly, deletion of adeB impacted only on the ability of strain AYE to form a biofilm on plastic and only on the virulence of strain Singapore 1 for Galleria mellonella. RNA-Seq revealed that loss of AdeRS or AdeB significantly altered the transcriptional landscape, resulting in the changed expression of many genes, notably those associated with antimicrobial resistance and virulence interactions. For example, A. baumannii lacking AdeRS displayed decreased expression of adeABC, pil genes, com genes, and a pgaC-like gene, whereas loss of AdeB resulted in increased expression of pil and com genes and decreased expression of ferric acinetobactin transport system genes. These data define the scope of AdeRS-mediated regulation, show that changes in the production of AdeABC mediate important phenotypes controlled by AdeRS, and suggest that AdeABC is a viable target for antimicrobial drug and antibiofilm discovery.

  1. The Acinetobacter baumannii Two-Component System AdeRS Regulates Genes Required for Multidrug Efflux, Biofilm Formation, and Virulence in a Strain-Specific Manner

    Science.gov (United States)

    Richmond, Grace E.; Evans, Laura P.; Anderson, Michele J.; Wand, Matthew E.; Bonney, Laura C.; Ivens, Alasdair; Chua, Kim Lee; Webber, Mark A.; Sutton, J. Mark; Peterson, Marnie L.

    2016-01-01

    ABSTRACT The opportunistic pathogen Acinetobacter baumannii is able to persist in the environment and is often multidrug resistant (MDR), causing difficulties in the treatment of infections. Here, we show that the two-component system AdeRS, which regulates the production of the AdeABC multidrug resistance efflux pump, is required for the formation of a protective biofilm in an ex vivo porcine mucosal model, which mimics a natural infection of the human epithelium. Interestingly, deletion of adeB impacted only on the ability of strain AYE to form a biofilm on plastic and only on the virulence of strain Singapore 1 for Galleria mellonella. RNA-Seq revealed that loss of AdeRS or AdeB significantly altered the transcriptional landscape, resulting in the changed expression of many genes, notably those associated with antimicrobial resistance and virulence interactions. For example, A. baumannii lacking AdeRS displayed decreased expression of adeABC, pil genes, com genes, and a pgaC-like gene, whereas loss of AdeB resulted in increased expression of pil and com genes and decreased expression of ferric acinetobactin transport system genes. These data define the scope of AdeRS-mediated regulation, show that changes in the production of AdeABC mediate important phenotypes controlled by AdeRS, and suggest that AdeABC is a viable target for antimicrobial drug and antibiofilm discovery. PMID:27094331

  2. De novo mutation in the dopamine transporter gene associates dopamine dysfunction with autism spectrum disorder

    DEFF Research Database (Denmark)

    Hamilton, P J; Campbell, N G; Sharma, S

    2013-01-01

    De novo genetic variation is an important class of risk factors for autism spectrum disorder (ASD). Recently, whole-exome sequencing of ASD families has identified a novel de novo missense mutation in the human dopamine (DA) transporter (hDAT) gene, which results in a Thr to Met substitution...... at site 356 (hDAT T356M). The dopamine transporter (DAT) is a presynaptic membrane protein that regulates dopaminergic tone in the central nervous system by mediating the high-affinity reuptake of synaptically released DA, making it a crucial regulator of DA homeostasis. Here, we report the first...

  3. Smooth solutions to the equation A+B=C

    CERN Document Server

    Lagarias, Jeffrey C

    2009-01-01

    This paper studies integer solutions to the ABC equation A+B+C=0 in which none of A, B, C has a large prime factor. Set H(A,B, C)= max(|A|,|B|,|C|) and set the smoothness S(A, B, C) to be the largest prime factor of ABC. We consider primitive solutions (gcd(A, B, C)=1) having smoothness no larger than a fixed power p of log H. Assuming the abc Conjecture we show that there are finitely many solutions if p8. We sketch some details of the proof of the latter result.

  4. GolS controls the response to gold by the hierarchical induction of Salmonella-specific genes that include a CBA efflux-coding operon.

    Science.gov (United States)

    Pontel, Lucas B; Audero, María E Pérez; Espariz, Martín; Checa, Susana K; Soncini, Fernando C

    2007-11-01

    Salmonella employs a specific set of proteins that allows it to detect the presence of gold salts in the environment and to mount the appropriate resistance response. This includes a P-type ATPase, GolT, and a small cytoplasmic metal binding protein, GolB. Their expression is controlled by a MerR-like sensor, GolS, which is highly selective for Au ions. Here, we identify a new GolS-controlled operon named gesABC which codes for a CBA efflux system, and establish its role in Au resistance. GesABC can also mediate drug resistance when induced by Au in a GolS-dependent manner, in a strain deleted in the main drug transporter acrAB. The GolS-controlled transcription of gesABC differs from the other GolS-regulated loci. It is activated by gold, but not induced by copper, even in a strain deleted of the main Cu transporter gene copA, which triggers a substantial GolS-dependent induction of golTS and golB. We demonstrate that the Au-dependent induction of gesABC transcription requires higher GolS levels than for the other members of the gol regulon. This correlates with a divergent GolS operator in the gesABC promoter. We propose that the hierarchical induction within the gol regulon allows Salmonella to cope with Au-contaminated environments.

  5. Pyrosequencing of the Camptotheca acuminata transcriptome reveals putative genes involved in camptothecin biosynthesis and transport

    Directory of Open Access Journals (Sweden)

    Sun Yongzhen

    2011-10-01

    Full Text Available Abstract Background Camptotheca acuminata is a Nyssaceae plant, often called the "happy tree", which is indigenous in Southern China. C. acuminata produces the terpenoid indole alkaloid, camptothecin (CPT, which exhibits clinical effects in various cancer treatments. Despite its importance, little is known about the transcriptome of C. acuminata and the mechanism of CPT biosynthesis, as only few nucleotide sequences are included in the GenBank database. Results From a constructed cDNA library of young C. acuminata leaves, a total of 30,358 unigenes, with an average length of 403 bp, were obtained after assembly of 74,858 high quality reads using GS De Novo assembler software. Through functional annotation, a total of 21,213 unigenes were annotated at least once against the NCBI nucleotide (Nt, non-redundant protein (Nr, Uniprot/SwissProt, Kyoto Encyclopedia of Genes and Genomes (KEGG, and Arabidopsis thaliana proteome (TAIR databases. Further analysis identified 521 ESTs representing 20 enzyme genes that are involved in the backbone of the CPT biosynthetic pathway in the library. Three putative genes in the upstream pathway, including genes for geraniol-10-hydroxylase (CaPG10H, secologanin synthase (CaPSCS, and strictosidine synthase (CaPSTR were cloned and analyzed. The expression level of the three genes was also detected using qRT-PCR in C. acuminata. With respect to the branch pathway of CPT synthesis, six cytochrome P450s transcripts were selected as candidate transcripts by detection of transcript expression in different tissues using qRT-PCR. In addition, one glucosidase gene was identified that might participate in CPT biosynthesis. For CPT transport, three of 21 transcripts for multidrug resistance protein (MDR transporters were also screened from the dataset by their annotation result and gene expression analysis. Conclusion This study produced a large amount of transcriptome data from C. acuminata by 454 pyrosequencing. According to

  6. Common Genetic Variation In Cellular Transport Genes and Epithelial Ovarian Cancer (EOC Risk.

    Directory of Open Access Journals (Sweden)

    Ganna Chornokur

    Full Text Available Defective cellular transport processes can lead to aberrant accumulation of trace elements, iron, small molecules and hormones in the cell, which in turn may promote the formation of reactive oxygen species, promoting DNA damage and aberrant expression of key regulatory cancer genes. As DNA damage and uncontrolled proliferation are hallmarks of cancer, including epithelial ovarian cancer (EOC, we hypothesized that inherited variation in the cellular transport genes contributes to EOC risk.In total, DNA samples were obtained from 14,525 case subjects with invasive EOC and from 23,447 controls from 43 sites in the Ovarian Cancer Association Consortium (OCAC. Two hundred seventy nine SNPs, representing 131 genes, were genotyped using an Illumina Infinium iSelect BeadChip as part of the Collaborative Oncological Gene-environment Study (COGS. SNP analyses were conducted using unconditional logistic regression under a log-additive model, and the FDR q<0.2 was applied to adjust for multiple comparisons.The most significant evidence of an association for all invasive cancers combined and for the serous subtype was observed for SNP rs17216603 in the iron transporter gene HEPH (invasive: OR = 0.85, P = 0.00026; serous: OR = 0.81, P = 0.00020; this SNP was also associated with the borderline/low malignant potential (LMP tumors (P = 0.021. Other genes significantly associated with EOC histological subtypes (p<0.05 included the UGT1A (endometrioid, SLC25A45 (mucinous, SLC39A11 (low malignant potential, and SERPINA7 (clear cell carcinoma. In addition, 1785 SNPs in six genes (HEPH, MGST1, SERPINA, SLC25A45, SLC39A11 and UGT1A were imputed from the 1000 Genomes Project and examined for association with INV EOC in white-European subjects. The most significant imputed SNP was rs117729793 in SLC39A11 (per allele, OR = 2.55, 95% CI = 1.5-4.35, p = 5.66x10-4.These results, generated on a large cohort of women, revealed associations between inherited cellular

  7. APOLLO 13: A News Bulletin from ABC

    Science.gov (United States)

    1974-01-01

    APOLLO 13: ABC breaks the news of a mishap aboard the spacecraft From the film documentary 'APOLLO 13: 'Houston, We've got a problem'', part of a documentary series on the APOLLO missions made in the early '70's and narrated by Burgess Meredith. APOLO 13 : Third manned lunar landing attempt with James A. Lovell, Jr., John L. Swigert, Jr., and Fred W. Haise, Jr. Pressure lost in SM oxygen system; mission aborted; LM used for life support. Mission Duration 142hrs 54mins 41sec

  8. abc: An extensible AspectJ compiler

    DEFF Research Database (Denmark)

    Avgustinov, Pavel; Christensen, Aske Simon; Hendren, Laurie;

    2005-01-01

    Research in the design of aspect-oriented programming languages requires a workbench that facilitates easy experimentation with new language features and implementation techniques. In particular, new features for AspectJ have been proposed that require extensions in many dimensions: syntax, type...... language. The use of Polyglot gives flexibility of syntax and type checking. The backend is built using the Soot framework, to give modular code generation and analyses. In this paper, we outline the design of abc, focusing mostly on how the design supports extensibility. We then provide a general overview...

  9. The A-B-C of recycling

    DEFF Research Database (Denmark)

    Thøgersen, John; Ølander, Carl Folke

    specifically the source separation of compostable kitchen waste. The investigation was carried out before and after the introduction of a system, facilitating such separation, in a Danish community. Hypotheses derived from the A-B-C model, predicting that changes over time in the correlation between attitude......A general framework for interpreting behaviour as co-determined by attitudes and structural conditions, developed by Guagnano, Stern, and Dietz for the field of environmental psychology but with general applicability, is used to identify determinants of consumers' recycling behaviour, more...

  10. Expression of the zinc transporters genes and metallothionein in obese women.

    Science.gov (United States)

    dos Santos Rocha, Paula Beatriz Krebsky; de Castro Amorim, Amanda; de Sousa, Artemizia Francisca; do Monte, Semíramis Jamil Hadad; da Mata Sousa, Luiz Claudio Demes; do Nascimento Nogueira, Nadir; Neto, José Machado Moita; do Nascimento Marreiro, Dilina

    2011-11-01

    Research has investigated the participation of zinc transport proteins and metallothionein in the metabolism of this mineral. However, studies about the genetic expression of these proteins in obese patients are scarce. The study determined the expression of zinc transporter protein codifying genes (ZnT-1, Zip-1 and Zip-3) and of metallothionein in 55 obese women, aged between 20 and 56 years. The assessment of body composition was carried out using anthropometric measurements and bioelectrical impedance. Zinc intake was obtained by recording diet over a 3-day period, and the nutritional analysis was carried out using NutWin software version 1.5. The plasmatic and erythrocytary zinc were analyzed by atomic absorption spectrophotometry (λ=213. 9 nm). The determination of mRNA expression of the zinc transporter proteins and metallothionein was carried out using blood, using the RT-PCR method. The mean values of body mass index were 37.9±5.5 kg/m2. The average intake of zinc was 9.4±2.3 mg/day. The analysis of the zinc plasma concentrations showed values of 58.4±10.9 μg/dL. The mean values of zinc in the erythroytes were 38.7±9.1 μg/g Hb. The metallothionein gene had a higher expression in the blood, when compared to zinc transporters ZnT-1, Zip-1, and Zip-3 (p=0.01). The study shows that there are alterations in the biochemical parameters of zinc in obese patients assessed, as well as higher expression of the codifying gene metallothionein, when compared to the investigated zinc transporters.

  11. Genetic Variations in SLCO Transporter Genes Contributing to Racial Disparity in Aggressiveness of Prostate Cancer

    Science.gov (United States)

    2015-10-01

    and to determine the association of genetic variants with prostate cancer aggressiveness. Tasks were also proposed in the reporting period (Year 1) to...data and to determine the association of genetic variants with prostate cancer aggressiveness, and summarize data and develop a manuscript. We also...AWARD NUMBER: W81XWH-14-1-0453 TITLE: Genetic Variations in SLCO Transporter Genes Contributing to Racial Disparity in Aggressiveness of

  12. Inflammation markers predict zinc transporter gene expression in women with type 2 diabetes mellitus.

    Science.gov (United States)

    Foster, Meika; Petocz, Peter; Samman, Samir

    2013-09-01

    The pathology of type 2 diabetes mellitus (DM) often is associated with underlying states of conditioned zinc deficiency and chronic inflammation. Zinc and omega-3 polyunsaturated fatty acids each exhibit anti-inflammatory effects and may be of therapeutic benefit in the disease. The present randomized, double-blind, placebo-controlled, 12-week trial was designed to investigate the effects of zinc (40 mg/day) and α-linolenic acid (ALA; 2 g/day flaxseed oil) supplementation on markers of inflammation [interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, C-reactive protein (CRP)] and zinc transporter and metallothionein gene expression in 48 postmenopausal women with type 2 DM. No significant effects of zinc or ALA supplementation were observed on inflammatory marker concentrations or fold change in zinc transporter and metallothionein gene expression. Significant increases in plasma zinc concentrations were observed over time in the groups supplemented with zinc alone or combined with ALA (P=.007 and P=.009, respectively). An impact of zinc treatment on zinc transporter gene expression was found; ZnT5 was positively correlated with Zip3 mRNA (Pzinc, while zinc supplementation abolished the relationship between ZnT5 and Zip10. IL-6 predicted the expression levels and CRP predicted the fold change of the ZnT5, ZnT7, Zip1, Zip7 and Zip10 mRNA cluster (Pzinc transporter and metallothionein gene expression support an interrelationship between zinc homeostasis and inflammation in type 2 DM.

  13. Identification and functional characterization of K+ transporters encoded by Legionella pneumophila kup genes

    OpenAIRE

    Hori, Juliana I.; Pereira, Marcelo S. F.; Roy, Craig R.; Nagai, Hiroki; Zamboni, Dario S.

    2013-01-01

    Legionnaires’ disease is an emerging, severe, pneumonia-like illness caused by the Gram-negative intracellular bacteria Legionella pneumophila, which are able to infect and replicate intracellularly in macrophages. Little is known regarding the mechanisms used by intracellular L. pneumophila for the acquisition of specific nutrients that are essential for bacterial replication. Here, we investigate three L. pneumophila genes with high similarity to the E. coli K+ transporters. These three gen...

  14. Association of attention-deficit disorder and the dopamine transporter gene

    Energy Technology Data Exchange (ETDEWEB)

    Cook, E.H. Jr.; Stein, M.A.; Krasowski, M.D.; Cox, N.J.; Olkon, D.M.; Kieffer, J.E.; Leventhal, B.L. [Univ. of Chicago, IL (United States)

    1995-04-01

    Attention-deficit hyperactivity disorder (ADHD) has been shown to be familial and heritable, in previous studies. As with most psychiatric disorders, examination of pedigrees has not revealed a consistent Mendelian mode of transmission. The response of ADHD patients to medications that inhibit the dopamine transporter, including methylphenidate, amphetamine, pemoline, and bupropion, led us to consider the dopamine transporter as a primary candidate gene for ADHD. To avoid effects of population stratification and to avoid the problem of classification of relatives with other psychiatric disorders as affected or unaffected, we used the haplotype-based haplotype relative risk (HHRR) method to test for association between a VNTR polymorphism at the dopamine transporter locus (DAT1) and DSM-III-R-diagnosed ADHD (N = 49) and undifferentiated attention-deficit disorder (UADD) (N = 8) in trios composed of father, mother, and affected offspring. HHRR analysis revealed significant association between ADHS/UADD and the 480-bp DAT1 allele (X{sup 2} 7.51, 1 df, P = .006). When cases of UADD were dropped from the analysis, similar results were found (X{sup 2} 7.29, 1 df, P = .007). If these findings are replicated, molecular analysis of the dopamine transporter gene may identify mutations that increase susceptibility to ADHD/UADD. Biochemical analysis of such mutations may lead to development of more effective therapeutic interventions. 36 refs., 4 tabs.

  15. Role of ZnuABC and ZinT in Escherichia coli O157:H7 zinc acquisition and interaction with epithelial cells

    Directory of Open Access Journals (Sweden)

    Nicolini Laura

    2011-02-01

    Full Text Available Abstract Background Zinc is an essential element for all living cells. Recent studies have shown that the ZnuABC zinc uptake system significantly contributes to the ability of several pathogens to multiply in the infected host and cause disease, suggesting that zinc is scarcely available within different tissues of the host. To better understand the role of zinc in bacterial pathogenicity, we have undertaken a functional characterization of the role of the ZnuABC-mediated zinc uptake pathway in enterohemorrhagic Escherichia coli O157:H7. Results In this work we have analyzed the expression and the role in metal uptake of ZnuA, the periplasmic component of the ZnuABC transporter, and of ZinT, another periplasmic protein which has been shown to contribute to zinc recruitment. We report that the expression of zinT and znuA, regulated by Zur, is induced in zinc-poor media, and that inactivation of either of the genes significantly decreases E. coli O157:H7 ability to grow in zinc depleted media. We also demonstrate that ZinT and ZnuA have not a redundant function in zinc homeostasis, as the role of ZinT is subordinated to the presence of ZnuA. Moreover, we have found that znuA and zinT are strongly induced in bacteria adhering to cultured epithelial cells and that lack of ZnuA affects the adhesion ability. In addition we have found that a fraction of apo-ZinT can be secreted outside the cell where the protein might sequester environmental zinc, inducing a condition of metal starvation in surrounding cells. Conclusions The here reported results demonstrate that ZnuABC plays a critical role in zinc uptake also in E. coli O157:H7 and that ZinT contributes to the ZnuA-mediated recruitment of zinc in the periplasmic space. Full functionality of the zinc import apparatus is required to facilitate bacterial adhesion to epithelial cells, indicating that the microbial ability to compete with the host cells for zinc binding is critical to establish successful

  16. Regulation of iron transport related genes by boron in the marine bacterium Marinobacter algicola DG893.

    Science.gov (United States)

    Romano, Ariel; Trimble, Lyndsay; Hobusch, Ashtian R; Schroeder, Kristine J; Amin, Shady A; Hartnett, Andrej D; Barker, Ryan A; Crumbliss, Alvin L; Carrano, Carl J

    2013-08-01

    While there has been extensive interest in the use of boron isotope ratios as a surrogate of pH in paleoclimate studies in the context of climate change-related questions, the high (0.4 mM) concentration and the depth-independent (conservative or non-nutrient-like) concentration profile of this element have led to boron being neglected as a potentially biologically relevant element in the modern ocean. Here we report that boron affects the expression of a number of protein and genes in the "algal-associated" Gram-negative marine bacterium Marinobacter algicola DG893. Most intriguingly, a number of these proteins and genes are related to iron uptake. In a recent separate publication we have shown that boron regulates one such iron transport related protein, i.e. the periplasmic iron binding protein FbpA via a direct interaction of the metalloid with this protein. Here we show that a number of other iron uptake related genes are also affected by boron but in the opposite way i.e. they are up-regulated. We propose that the differential effect of boron on FbpA expression relative to other iron transport related genes is a result of an interaction between boron and the global iron regulatory protein Fur.

  17. Piperlongumine selectively suppresses ABC-DLBCL through inhibition of NF-κB p65 subunit nuclear import

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Mingshan [Blood Diseases Institute, Xuzhou Medical College, Xuzhou, Jiangsu (China); Jiangsu Key Laboratory of Bone Marrow Stem Cell, Xuzhou Medical College, Xuzhou, Jiangsu (China); Department of Hematology, Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu (China); Shen, Yangling; Xu, Xiaoyu [Blood Diseases Institute, Xuzhou Medical College, Xuzhou, Jiangsu (China); Jiangsu Key Laboratory of Bone Marrow Stem Cell, Xuzhou Medical College, Xuzhou, Jiangsu (China); Yao, Yao; Fu, Chunling [Blood Diseases Institute, Xuzhou Medical College, Xuzhou, Jiangsu (China); Jiangsu Key Laboratory of Bone Marrow Stem Cell, Xuzhou Medical College, Xuzhou, Jiangsu (China); Department of Hematology, Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu (China); Yan, Zhiling [Department of Hematology, Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu (China); Wu, Qingyun [Blood Diseases Institute, Xuzhou Medical College, Xuzhou, Jiangsu (China); Jiangsu Key Laboratory of Bone Marrow Stem Cell, Xuzhou Medical College, Xuzhou, Jiangsu (China); Department of Hematology, Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu (China); Cao, Jiang; Sang, Wei [Department of Hematology, Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu (China); Zeng, Lingyu [Blood Diseases Institute, Xuzhou Medical College, Xuzhou, Jiangsu (China); Jiangsu Key Laboratory of Bone Marrow Stem Cell, Xuzhou Medical College, Xuzhou, Jiangsu (China); Department of Hematology, Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu (China); Li, Zhenyu [Department of Hematology, Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu (China); Liu, Xuejiao, E-mail: liuxuejiao0923@126.com [Insititute of Nervous System Diseases, Xuzhou Medical College, Xuzhou, Jiangsu (China); and others

    2015-07-10

    Constitutive NF-κB activation is required for survival of activated B cell-like subtype of diffuse large B cell lymphoma (ABC-DLBCL). However, current NF-κB targeting strategies lack cancer cell specificity. Here, we identified a novel inhibitor, piperlongumine, features direct binding to NF-κB p65 subunit and suppression of p65 nuclear import. This was accompanied by NF-κB reporter activity suppression and NF-κB target gene downregulation. Moreover, mutation of Cys{sup 38} to Ser in p65 abolished this effect of piperlongumine on inhibition of p65 nuclear import. Furthermore, we show that piperlongumine selectively inhibited proliferation and induced apoptosis of ABC-DLBCL cells. Most notably, it has been reported that piperlongumine did not affect normal cells even at high doses and was nontoxic to animals. Hence, our current study provides new insight into piperlongumine's mechanism of action and novel approach to ABC-DLBCL target therapy. - Highlights: • Current NF-κB targeting strategies lack cancer cell specificity. • Piperlongumine inhibits NF-κB p65 subunit nuclear import via directly binding to p65. • Piperlongumine selectively inhibits proliferation of ABC-DLBCL cells. • This study provides a novel approach to ABC-DLBCL target therapy.

  18. The Oligopeptide Transporters: A Small Gene Family with a Diverse Group of Substrates and Functions?

    Institute of Scientific and Technical Information of China (English)

    Mark Lubkowitz

    2011-01-01

    T Genes in the Oligopeptide Transport family encode integral membrane proteins that are believed to translocate their substrates from either the extracellular environment or an organelle into the cytosol. Phylogenetic analyses of plant transporters have revealed two distant clades: the Yellow Stripe-Like (YSL) proteins and the so-called Oligopeptide Transporters (OPTs), for which the family was named. Three categories of substrates have been identified for this family: small peptides, secondary amino acids bound to metals, and glutathione. Notably, the YSL transporters are involved in metal homeostasis through the translocation of metal-chelates, indicating a level of conservation both in biological function as well as substrates. In contrast, the functions of OPT proteins seem to be less defined and, in this review, I will examine the supporting and contradictory evidence for the proposed roles of OPTs in such diverse functions as long-distance sulfur distribution, nitrogen mobilization, metal homeostasis, and heavy metal sequestration through the transport of glutathione, metal-chelates, and peptides.

  19. Zinc-transporter genes in human visceral and subcutaneous adipocytes: lean versus obese.

    Science.gov (United States)

    Smidt, Kamille; Pedersen, Steen B; Brock, Birgitte; Schmitz, Ole; Fisker, Sanne; Bendix, Jørgen; Wogensen, Lise; Rungby, Jørgen

    2007-01-29

    Zinc ions influence adipose tissue metabolism by regulating leptin secretion and by promoting free fatty acid release and glucose uptake. The mechanisms controlling zinc metabolism in adipose tissue are unknown. We therefore examined the gene-expression levels of a number of zinc-transporting proteins in adipose tissue, comparing subcutaneous fat with visceral fat from lean and obese humans. Both ZnT-proteins responsible for zinc transport from cytosol to extracellular compartments and intracellular vesicles and Zip-proteins responsible for zinc transport to the cytoplasm were expressed in all samples. This suggests that zinc metabolism in adipocytes is actively controlled by zinc-transporters. The expression levels were different in lean and obese subjects suggesting a role for these proteins in obesity. Furthermore, the expression levels were different from subcutaneous fat to intra-abdominal fat suggesting that the metabolic activity in adipocytes is to some extent dependent upon zinc and the activity of zinc-transporting proteins or vice versa.

  20. Tripartite ATP-independent periplasmic transporters: application of a relational database for genome-wide analysis of transporter gene frequency and organization.

    Science.gov (United States)

    Mulligan, Christopher; Kelly, David J; Thomas, Gavin H

    2007-01-01

    Tripartite ATP-independent periplasmic (TRAP) transporters are a family of extracytoplasmic solute receptor-dependent secondary transporters that are widespread in the prokaryotic world but which have not been extensively studied. Here, we present results of a genome-wide analysis of TRAP sequences and genome organization from application of TRAPDb, a relational database created for the collection, curation and analysis of TRAP sequences. This has revealed a specific enrichment in the number of TRAP transporters in several bacteria which is consistent with increased use of TRAP transporters in saline environments. Additionally, we report a number of new organizations of TRAP transporter genes and proteins which suggest the recruitment of TRAP transporter components for use in other biological contexts.

  1. abc: The AspectBench Compiler for AspectJ

    DEFF Research Database (Denmark)

    Allan, Chris; Avgustinov, Pavel; Christensen, Aske Simon;

    2005-01-01

    abc is an extensible, optimising compiler for AspectJ. It has been designed as a workbench for experimental research in aspect-oriented programming languages and compilers. We outline a programme of research in these areas, and we review how abc can help in achieving those research goals...

  2. Amino acid transport in taxonomically diverse cyanobacteria and identification of two genes encoding elements of a neutral amino acid permease putatively involved in recapture of leaked hydrophobic amino acids.

    Science.gov (United States)

    Montesinos, M L; Herrero, A; Flores, E

    1997-02-01

    The activities of uptake of thirteen 14C-labeled amino acids were determined in nine cyanobacteria, including the unicellular strains Synechococcus sp. strain PCC 7942 and Synechocystis sp. strain PCC 6803; the filamentous strain Pseudanabaena sp. strain PCC 6903, and the filamentous, heterocyst-forming strains Anabaena sp. strains PCC 7120 and PCC 7937; Nostoc sp. strains PCC 7413 and PCC 7107; Calothrix sp. strain PCC 7601 (which is a mutant unable to develop heterocysts); and Fischerella muscicola UTEX 1829. Amino acid transport mutants, selected as mutants resistant to some amino acid analogs, were isolated from the Anabaena, Nostoc, Calothrix, and Pseudanabaena strains. All of the tested cyanobacteria bear at least a neutral amino acid transport system, and some strains also bear transport systems specific for basic or acidic amino acids. Two genes, natA and natB, encoding elements (conserved component, NatA, and periplasmic binding protein, NatB) of an ABC-type permease for neutral amino acids were identified by insertional mutagenesis of strain PCC 6803 open reading frames from the recently published genomic DNA sequence of this cyanobacterium. DNA sequences homologous to natA and natB from strain PCC 6803 were detected by hybridization in eight cyanobacterial strains tested. Mutants unable to transport neutral amino acids, including natA and natB insertional mutants, accumulated in the extracellular medium a set of amino acids that always included Ala, Val, Phe, Ile, and Leu. A general role for a cyanobacterial neutral amino acid permease in recapture of hydrophobic amino acids leaked from the cells is suggested.

  3. ABC Transporters and the Alzheimer’s Disease Enigma

    OpenAIRE

    Andrea eWolf; Bjoern eBauer; Hartz, Anika M. S.

    2012-01-01

    Alzheimer’s disease (AD) is considered the “disease of the twenty-first century.” With a 10-fold increase in global incidence over the past 100 years, AD is now reaching epidemic proportions and by all projections, AD patient numbers will continue to rise. Despite intense research efforts, AD remains a mystery and effective therapies are still unavailable. This represents an unmet need resulting in clinical, social, and economic problems. Over the last decade, a new AD research focus has emer...

  4. Sustained Delivery of Chondroitinase ABC from Hydrogel System

    Directory of Open Access Journals (Sweden)

    Filippo Rossi

    2012-03-01

    Full Text Available In the injured spinal cord, chondroitin sulfate proteoglycans (CSPGs are the principal responsible of axon growth inhibition and they contribute to regenerative failure, promoting glial scar formation. Chondroitinase ABC (chABC is known for being able to digest proteoglycans, thus degrading glial scar and favoring axonal regrowth. However, its classic administration is invasive, infection-prone and clinically problematic. An agarose-carbomer (AC1 hydrogel, already used in SCI repair strategies, was here investigated as a delivery system capable of an effective chABC administration: the material ability to include chABC within its pores and the possibility to be injected into the target tissue were firstly proved. Subsequently, release kinetic and the maintenance of enzymatic activity were positively assessed: AC1 hydrogel was thus confirmed to be a feasible tool for chABC delivery and a promising device for spinal cord injury topic repair strategies.

  5. Genetic variation in the serotonin transporter gene influences ERP old/new effects during recognition memory.

    Science.gov (United States)

    Ross, Robert S; Medrano, Paolo; Boyle, Kaitlin; Smolen, Andrew; Curran, Tim; Nyhus, Erika

    2015-11-01

    Recognition memory is defined as the ability to recognize a previously encountered stimulus and has been associated with spatially and temporally distinct event-related potentials (ERPs). Allelic variations of the serotonin transporter gene (SLC6A4) have recently been shown to impact memory performance. Common variants of the serotonin transporter-linked polymorphic region (5HTTLPR) of the SLC6A4 gene result in long (l) and short (s) allelic variants with carriers of the s allele having lowered transcriptional efficiency. Thus, the current study examines the effects polymorphisms of the SLC6A4 gene have on performance and ERP amplitudes commonly associated with recognition memory. Electroencephalogram (EEG), genetic, and behavioral data were collected from sixty participants as they performed an item and source memory recognition task. In both tasks, participants studied and encoded 200 words, which were then mixed with 200 new words during retrieval. Participants were monitored with EEG during the retrieval portion of each memory task. EEG electrodes were grouped into four ROIs, left anterior superior, right anterior superior, left posterior superior, and right posterior superior. ERP mean amplitudes during hits in the item and source memory task were compared to correctly recognizing new items (correct rejections). Results show that s-carriers have decreased mean hit amplitudes in both the right anterior superior ROI 1000-1500ms post stimulus during the source memory task and the left anterior superior ROI 300-500ms post stimulus during the item memory task. These results suggest that individual differences due to genetic variation of the serotonin transporter gene influences recognition memory.

  6. The Role of the Actin Cytoskeleton and Lipid Rafts in the Localization and Function of the ABCC1 Transporter

    Directory of Open Access Journals (Sweden)

    Jan Willem Kok

    2014-01-01

    Full Text Available ATP-binding cassette (ABC transporters are known to be important factors in multidrug resistance of tumor cells. Lipid rafts have been implicated in their localization in the plasma membrane, where they function as drug efflux pumps. This specific localization in rafts may support the activity of ABC/Abc transporters. This raises questions regarding the nature and composition of the lipid rafts that harbor ABC/Abc transporters and the dependence of ABC/Abc transporters—concerning their localization and activity—on lipid raft constituents. Here we review our work of the past 10 years aimed at evaluating whether ABC/Abc transporters are dependent on a particular membrane environment for their function. What is the nature of this membrane environment and which of the lipid raft constituents are important for this dependency? It turns out that cortical actin is of major importance for stabilizing the localization and function of the ABC/Abc transporter, provided it is localized in an actin-dependent subtype of lipid rafts, as is the case for human ABCC1/multidrug resistance-related protein 1 (MRP1 and rodent Abcc1/Mrp1 but not human ABCB1/P-glycoprotein (PGP. On the other hand, sphingolipids do not appear to be modulators of ABCC1/MRP1 (or Abcc1/Mrp1, even though they are coregulated during drug resistance development.

  7. Phosphate Transporter Genes as Reliable Gene Markers for the Identification and Discrimination of Arbuscular Mycorrhizal Fungi in the Genus Glomus ▿ §

    Science.gov (United States)

    Sokolski, Serge; Dalpé, Yolande; Piché, Yves

    2011-01-01

    An inorganic phosphate transporter gene sequence (852-bp section) allowed discrimination between 10 Glomus fungal species represented by 25 strains. It was particularly valuable in differentiating between morphologically similar species with nucleotide and amino acid sequence differences higher than 3%. This gene is proposed as a reliable barcode for the Glomeromycetes. PMID:21193669

  8. The cmbT gene encodes a novel major facilitator multidrug resistance transporter in Lactococcus lactis.

    Science.gov (United States)

    Filipic, Brankica; Golic, Natasa; Jovcic, Branko; Tolinacki, Maja; Bay, Denice C; Turner, Raymond J; Antic-Stankovic, Jelena; Kojic, Milan; Topisirovic, Ljubisa

    2013-01-01

    Functional characterization of the multidrug resistance CmbT transporter was performed in Lactococcus lactis. The cmbT gene is predicted to encode an efflux protein homologous to the multidrug resistance major facilitator superfamily. The cmbT gene (1377 bp) was cloned and overexpressed in L. lactis NZ9000. Results from cell growth studies revealed that the CmbT protein has an effect on host cell resistance to lincomycin, cholate, sulbactam, ethidium bromide, Hoechst 33342, sulfadiazine, streptomycin, rifampicin, puromycin and sulfametoxazole. Moreover, in vivo transport assays showed that overexpressed CmbT-mediated extrusion of ethidium bromide and Hoechst 33342 was higher than in the control L. lactis NZ9000 strain. CmbT-mediated extrusion of Hoechst 33342 was inhibited by the ionophores nigericin and valinomycin known to dissipate proton motive force. This indicates that CmbT-mediated extrusion is based on a drug-proton antiport mechanism. Taking together results obtained in this study, it can be concluded that CmbT is a novel major facilitator multidrug resistance transporter candidate in L. lactis, with a possible signaling role in sulfur metabolism.

  9. Seasonal variations in antibiotic resistance gene transport in the almendares river, havana, cuba.

    Science.gov (United States)

    Knapp, Charles W; Lima, Lazaro; Olivares-Rieumont, Susana; Bowen, Emma; Werner, David; Graham, David W

    2012-01-01

    Numerous studies have quantified antibiotic resistance genes (ARG) in rivers and streams around the world, and significant relationships have been shown that relate different pollutant outputs and increased local ARG levels. However, most studies have not considered ambient flow conditions, which can vary dramatically especially in tropical countries. Here, ARG were quantified in water column and sediment samples during the dry- and wet-seasons to assess how seasonal and other factors influence ARG transport down the Almendares River (Havana, Cuba). Eight locations were sampled and stream flow estimated during both seasons; qPCR was used to quantify four tetracycline, two erythromycin, and three beta-lactam resistance genes. ARG concentrations were higher in wet-season versus dry-season samples, which combined with higher flows, indicated much greater ARG transport downstream during the wet-season. However, water column ARG levels were more spatially variable in the dry-season than the wet-season, with the proximity of waste outfalls strongly influencing local ARG levels. Results confirm that dry-season sampling provides a useful picture of the impact of individual waste inputs on local stream ARG levels, whereas the majority of ARGs in this tropical river were transported downstream during the wet-season, possibly due to re-entrainment of ARG from sediments.

  10. Seasonal variations in antibiotic resistance gene transport in the Almendares River, Havana, Cuba

    Directory of Open Access Journals (Sweden)

    Charles W Knapp

    2012-11-01

    Full Text Available Numerous studies have quantified antibiotic resistance genes (ARG in rivers and streams around the world, and significant relationships have been shown that relate different pollutant outputs and increased local ARG levels. However, most studies have not considered ambient flow conditions, which can vary dramatically especially in tropical countries. Here, ARG were quantified in water-column and sediment samples during the dry-and wet-seasons to assess how seasonal and other factors influence ARG transport down the Almendares River (Havana, Cuba. Eight locations were sampled and stream flow estimated during both seasons; qPCR was used to quantify four tetracycline, two erythromycin, and three beta-lactam resistance genes. ARG concentrations were higher in wet-season versus dry-season samples, which combined with higher flows, indicated greater ARG transport downstream during the wet season. Water-column ARG levels were more spatially variable in the dry-season than the wet-season, with the proximity of waste outfalls strongly influencing local ARG levels. Results confirm that dry-season sampling provides a useful picture of the impact of individual waste inputs on local stream ARG levels, whereas, the majority of ARGs in this tropical river were transported downstream during the wet season, possibly due to re-entrainment of ARG from sediments.

  11. Coordinative modulation of human zinc transporter 2 gene expression through active and suppressive regulators.

    Science.gov (United States)

    Lu, Yu-Ju; Liu, Ya-Chuan; Lin, Meng-Chieh; Chen, Yi-Ting; Lin, Lih-Yuan

    2015-04-01

    Zinc transporter 2 (ZnT2) is one of the cellular factors responsible for Zn homeostasis. Upon Zn overload, ZnT2 reduces cellular Zn by transporting it into excretory vesicles. We investigated the molecular mechanism that regulates human ZnT2 (hZnT2) gene expression. Zn induces hZnT2 expression in dose- and time-dependent manners. Overexpression of metal-responsive transcription factor 1 (MTF-1) increases hZnT2 transcription, whereas depletion of MTF-1 reduces hZnT2 expression. There are five putative metal response elements (MREs) within 1kb upstream of the hZnT2 gene. A serial deletion of the hZnT2 promoter region (from 5' to 3') shows that the two MREs proximal to the gene are essential for Zn-induced promoter activity. Further mutation analysis concludes that the penultimate MRE (MREb) supports the metal-induced promoter activity. The hZnT2 promoter has also a zinc finger E-box binding homeobox (ZEB) binding element. Mutation or deletion of this ZEB binding element elevates the basal and Zn-induced hZnT2 promoter activities. Knockdown of ZEB1 mRNA enhances the hZnT2 transcript level in HEK-293 cells. In MCF-7 (ZEB-deficient) cells, expression of ZEB proteins attenuates the Zn-induced hZnT2 expression. However, expressions of MTF-1 target genes such as human ZnT1 and metallothionein IIA were not affected. Our study shows the expression of the hZnT2 gene is coordinately regulated via active and suppressive modulators.

  12. ArgR is an essential local transcriptional regulator of the arcABC operon in Streptococcus suis and is crucial for biological fitness in an acidic environment.

    Science.gov (United States)

    Fulde, Marcus; Willenborg, Joerg; de Greeff, Astrid; Benga, Laurentiu; Smith, Hilde E; Valentin-Weigand, Peter; Goethe, Ralph

    2011-02-01

    Streptococcus suis is one of the most important pathogens in pigs and can also cause severe infections in humans. Despite its clinical relevance, very little is known about the factors that contribute to its virulence. Recently, we identified a new putative virulence factor in S. suis, the arginine deiminase system (ADS), an arginine catabolic enzyme system encoded by the arcABC operon, which enables S. suis to survive in an acidic environment. In this study, we focused on ArgR, an ADS-associated regulator belonging to the ArgR/AhrC arginine repressor family. Using an argR knockout strain we were able to show that ArgR is essential for arcABC operon expression and necessary for the biological fitness of S. suis. By cDNA expression microarray analyses and quantitative real-time RT-PCR we found that the arcABC operon is the only gene cluster regulated by ArgR, which is in contrast to the situation in many other bacteria. Reporter gene analysis with gfp under the control of the arcABC promoter demonstrated that ArgR is able to activate the arcABC promoter. Electrophoretic mobility shift assays with fragments of the arcABC promoter and recombinant ArgR, and chromatin immunoprecipitation with antibodies directed against ArgR, revealed that ArgR interacts with the arcABC promoter in vitro and in vivo by binding to a region from -147 to -72 bp upstream of the transcriptional start point. Overall, our results show that in S. suis, ArgR is an essential, system-specific transcriptional regulator of the ADS that interacts directly with the arcABC promoter in vivo.

  13. A tissue-specific role for intraflagellar transport genes during craniofacial development

    Science.gov (United States)

    Williams, Trevor J.; Snedeker, John; Brugmann, Samantha A.

    2017-01-01

    Primary cilia are nearly ubiquitous, cellular projections that function to transduce molecular signals during development. Loss of functional primary cilia has a particularly profound effect on the developing craniofacial complex, causing several anomalies including craniosynostosis, micrognathia, midfacial dysplasia, cleft lip/palate and oral/dental defects. Development of the craniofacial complex is an intricate process that requires interactions between several different tissues including neural crest cells, neuroectoderm and surface ectoderm. To understand the tissue-specific requirements for primary cilia during craniofacial development we conditionally deleted three separate intraflagellar transport genes, Kif3a, Ift88 and Ttc21b with three distinct drivers, Wnt1-Cre, Crect and AP2-Cre which drive recombination in neural crest, surface ectoderm alone, and neural crest, surface ectoderm and neuroectoderm, respectively. We found that tissue-specific conditional loss of ciliary genes with different functions produces profoundly different facial phenotypes. Furthermore, analysis of basic cellular behaviors in these mutants suggests that loss of primary cilia in a distinct tissue has unique effects on development of adjacent tissues. Together, these data suggest specific spatiotemporal roles for intraflagellar transport genes and the primary cilium during craniofacial development. PMID:28346501

  14. Growth Hormone Receptor Knockdown Sensitizes Human Melanoma Cells to Chemotherapy by Attenuating Expression of ABC Drug Efflux Pumps.

    Science.gov (United States)

    Basu, Reetobrata; Baumgaertel, Nicholas; Wu, Shiyong; Kopchick, John J

    2017-03-14

    Melanoma remains one of the most therapy-resistant forms of human cancer despite recent introductions of highly efficacious targeted therapies. The intrinsic therapy resistance of human melanoma is largely due to abundant expression of a repertoire of xenobiotic efflux pumps of the ATP-binding cassette (ABC) transporter family. Here, we report that GH action is a key mediator of chemotherapeutic resistance in human melanoma cells. We investigated multiple ABC efflux pumps (ABCB1, ABCB5, ABCB8, ABCC1, ABCC2, ABCG1, and ABCG2) reportedly associated with melanoma drug resistance in different human melanoma cells and tested the efficacy of five different anti-cancer compounds (cisplatin, doxorubicin, oridonin, paclitaxel, vemurafenib) with decreased GH action. We found that GH treatment of human melanoma cells upregulates expression of multiple ABC transporters and increases the EC50 of melanoma drug vemurafenib. Also, vemurafenib-resistant melanoma cells had upregulated levels of GH receptor (GHR) expression as well as ABC efflux pumps. GHR knockdown (KD) using siRNA in human melanoma cells treated with sub-EC50 doses of anti-tumor compounds resulted in significantly increased drug retention, decreased cell proliferation and increased drug efficacy, compared to mock-transfected controls. Our set of findings identify an unknown mechanism of GH regulation in mediating melanoma drug resistance and validates GHR as a unique therapeutic target for sensitizing highly therapy-resistant human melanoma cells to lower doses of anti-cancer drugs.

  15. A cholesterol-free, high-fat diet suppresses gene expression of cholesterol transporters in murine small intestine

    NARCIS (Netherlands)

    den Bosch, Heleen M. de Vogel-van; de Wit, Nicole J. W.; Hooiveld, Guido J. E. J.; Vermeulen, Hanneke; van der Veen, Jelske N.; Houten, Sander M.; Kuipers, Folkert; Mueller, Michael; van der Meer, Roelof

    2008-01-01

    A cholesterol-free, high-fat diet suppresses gene expression of cholesterol transporters in murine small intestine. Am J Physiol Gastrointest Liver Physiol 294: G1171-G1180, 2008. First published March 20, 2008; doi:10.1152/ajpgi.00360.2007.-Transporters present in the epithelium of the small intest

  16. Cloning and functional expression in Escherichia coli of the gene encoding the di- and tripeptide transport protein of Lactobacillus helveticus

    NARCIS (Netherlands)

    Nakajima, H.; Hagting, A; Kunji, E.R S; Poolman, B.; Konings, W.N

    1997-01-01

    The gene encoding the di- and tripeptide transport protein (DtpT) of Lactobacillus helveticus (DtpT(LH)) was cloned with the aid of the inverse PCR technique and used to complement the dipeptide transport-deficient and proline-auxotrophic Escherichia coil E1772. Functional expression of the peptide

  17. Polymorphisms in the dopamine transporter gene (SLC6A3/DAT1) and alcohol dependence in humans: a systematic review

    NARCIS (Netherlands)

    Zwaluw, C.S. van der; Engels, R.C.M.E.; Buitelaar, J.K.; Verkes, R.J.; Franke, B.; Scholte, R.H.J.

    2009-01-01

    Dopamine neurotransmission has been a key player in attempts to identify genetic factors involved in alcohol dependence. The dopamine transporter terminates dopaminergic neurotransmission, making the gene encoding the transporter (SLC6A3/DAT1) an attractive candidate in clinical studies on alcohol d

  18. Polymorphisms in the dopamine transporter gene (SLC6A3/DAT1) and alcohol dependence in humans: a systematic review.

    NARCIS (Netherlands)

    Zwaluw, C.S. van der; Engels, R.C.M.E.; Buitelaar, J.K.; Verkes, R.J.; Franke, B.; Scholte, R.H.J.

    2009-01-01

    Dopamine neurotransmission has been a key player in attempts to identify genetic factors involved in alcohol dependence. The dopamine transporter terminates dopaminergic neurotransmission, making the gene encoding the transporter (SLC6A3/DAT1) an attractive candidate in clinical studies on alcohol d

  19. ABC for network managers. Key to efficiency improvement; ABC voor netbeheerders. Sleutel tot efficiencyverbetering

    Energy Technology Data Exchange (ETDEWEB)

    Osse, M.J.E. [Ernst and Young Consulting, Utrecht (Netherlands)

    1999-12-01

    In order to give everyone who wants to supply electricity a fair chance, network managers must make costs transparent. Next to the rules for the tariff code, they can also make use of a cost charging method, the so-called ABC-N (Activity Based Costing for Networks). This method makes the costs transparent and therefore also helps the network managers to improve their efficiency. That is essential in view of the pressure from the supervisor for the Dutch electric power sector.

  20. Quantitative PCR for glucose transporter and tristetraprolin family gene expression in cultured mouse adipocytes and macrophages.

    Science.gov (United States)

    Cao, Heping; Cao, Fangping; Roussel, Anne-Marie; Anderson, Richard A

    2013-12-01

    Quantitative real-time PCR (qPCR) such as TaqMan and SYBR Green qPCR are widely used for gene expression analysis. The drawbacks of SYBR Green assay are that the dye binds to any double-stranded DNA which can generate false-positive signals and that the length of the amplicon affects the intensity of the amplification. Previous results demonstrate that TaqMan assay is more sensitive but generates lower calculated expression levels than SYBR Green assay in quantifying seven mRNAs in tung tree tissues. The objective of this study is to expand the analysis using animal cells. We compared both qPCR assays for quantifying 24 mRNAs including those coding for glucose transporter (Glut) and mRNA-binding protein tristetraprolin (TTP) in mouse 3T3-L1 adipocytes and RAW264.7 macrophages. The results showed that SYBR Green and TaqMan qPCR were reliable for quantitative gene expression in animal cells. This result was supported by validation analysis of Glut and TTP family gene expression. However, SYBR Green qPCR overestimated the expression levels in most of the genes tested. Finally, both qPCR instruments (Bio-Rad's CFX96 real-time system and Applied Biosystems' Prism 7700 real-time PCR instrument) generated similar gene expression profiles in the mouse cells. These results support the conclusion that both qPCR assays (TaqMan and SYBR Green qPCR) and both qPCR instruments (Bio-Rad's CFX96 real-time system and Applied Biosystems' Prism 7700 real-time PCR instrument) are reliable for quantitative gene expression analyses in animal cells but SYBR Green qPCR generally overestimates gene expression levels than TaqMan qPCR.

  1. A phosphate transport system is required for symbiotic nitrogen fixation by Rhizobium meliloti.

    OpenAIRE

    Bardin, S.; Dan, S.; Osteras, M.; Finan, T M

    1996-01-01

    The bacterium Rhizobium meliloti forms N2-fixing root nodules on alfalfa plants. The ndvF locus, located on the 1,700-kb pEXO megaplasmid of R. meliloti, is required for nodule invasion and N2 fixation. Here we report that ndvF contains four genes, phoCDET, which encode an ABC-type transport system for the uptake of Pi into the bacteria. The PhoC and PhoD proteins are homologous to the Escherichia coli phosphonate transport proteins PhnC and PhnD. The PhoT and PhoE proteins are homologous to ...

  2. Serotonin transporter gene polymorphisms: Relation with platelet serotonin level in patients with primary Sjogren's syndrome.

    Science.gov (United States)

    Markeljevic, J; Sarac, H; Bozina, N; Henigsberg, N; Simic, M; Cicin Sain, L

    2015-05-15

    Significantly lower platelet serotonin level (PSL) in patients with primary Sjogren's syndrome (pSS) than in healthy controls has been reported in our prior studies. In the present report, we demonstrated effect of functional polymorphisms in the serotonin transporter gene (5-HTT) on PSL. We describe a group of 61 pSS patients and 100 healthy individuals subjects, who received PSL measurement in our prior study. All subjects were genotyped for the promoter 5-HTTLPR (L/S), rs25531 (A/G) and intronic 5-HTTVNTRin2 (l/s) polymorphisms. Overall, the presence of 5-HTTVNTRin2 ss genotype was associated with significantly lower PSL in pSS patients, not in healthy controls. Reduced PSL in pSS patients is in line with hypothesis of association between chronic immunoinflammation and 5-HT system dysregulation, identifying additional mechanisms such as altered 5-HT transport as potential genetic factor contributing to PSL depletion.

  3. A roadmap for zinc transport into the developing barley grain. Gene expression profiling using laser microdissection

    DEFF Research Database (Denmark)

    Borg, Søren; Tauris, Birgitte

    2011-01-01

    Nutrients destined for the developing cereal grain encounter several restricting barriers on their path towards their final storage sites in the grain. In order to identify transporters and chelating agents that may be involved in transport and deposition of zinc in the barley grain, expression...... profiles have been generated of four different tissue types: the transfer cells, the aleurone layer, the endosperm, and the embryo. Cells from these tissues were isolated with the 'laser capture microdissection' technology and the extracted RNA was subjected to three rounds of T7-based amplification...... were taken into account. On the basis of the expression levels of a number of metal homeostasis genes, a working model is proposed for the translocation of zinc from the phloem to the storage sites in the developing grain....

  4. Molecular cloning and expression analysis of the sucrose transporter gene family from Theobroma cacao L.

    Science.gov (United States)

    Li, Fupeng; Wu, Baoduo; Qin, Xiaowei; Yan, Lin; Hao, Chaoyun; Tan, Lehe; Lai, Jianxiong

    2014-08-10

    In this study, we performed cloning and expression analysis of six putative sucrose transporter genes, designated TcSUT1, TcSUT2, TcSUT3, TcSUT4, TcSUT5 and TcSUT6, from the cacao genotype 'TAS-R8'. The combination of cDNA and genomic DNA sequences revealed that the cacao SUT genes contained exon numbers ranging from 1 to 14. The average molecular mass of all six deduced proteins was approximately 56 kDa (range 52 to 66 kDa). All six proteins were predicted to exhibit typical features of sucrose transporters with 12 trans-membrane spanning domains. Phylogenetic analysis revealed that TcSUT2 and TcSUT4 belonged to Group 2 SUT and Group 4 SUT, respectively, and the other TcSUT proteins were belonging to Group 1 SUT. Real-time PCR was conducted to investigate the expression pattern of each member of the SUT family in cacao. Our experiment showed that TcSUT1 was expressed dominantly in pods and that, TcSUT3 and TcSUT4 were highly expressed in both pods and in bark with phloem. Within pods, TcSUT1 and TcSUT4 were expressed more in the seed coat and seed from the pod enlargement stage to the ripening stage. TcSUT5 expression sharply increased to its highest expression level in the seed coat during the ripening stage. Expression pattern analysis indicated that TcSUT genes may be associated with photoassimilate transport into developing seeds and may, therefore, have an impact on seed production.

  5. Identification and functional characterization of K+ transporters encoded by Legionella pneumophila kup genes

    Science.gov (United States)

    Hori, Juliana I.; Pereira, Marcelo S.F.; Roy, Craig R.; Nagai, Hiroki; Zamboni, Dario S.

    2013-01-01

    Summary Legionnaires’ disease is an emerging, severe, pneumonia-like illness caused by the Gram-negative intracellular bacteria Legionella pneumophila, which are able to infect and replicate intracellularly in macrophages. Little is known regarding the mechanisms used by intracellular L. pneumophila for the acquisition of specific nutrients that are essential for bacterial replication. Here, we investigate three L. pneumophila genes with high similarity to the E. coli K+ transporters. These three genes were expressed by L. pneumophila and have been designated kupA, kupB and kupC. Investigation using the L. pneumophila kup mutants revealed that kupA is involved in K+ acquisition during axenic growth. The kupA mutants replicated efficiently in rich axenic media, but poorly in a chemically defined medium. The kupA mutants were defective in the recruitment of polyubiquitinated proteins to the Legionella-containing vacuole that is formed in macrophages and displayed an intracellular multiplication defect during the replication in Acanthamoeba castellanii and in mouse macrophages. We found that bafilomycin treatment of macrophages was able to rescue the growth defects of kupA mutants, but it did not influence the replication of wild-type bacteria. The defects identified in kupA mutants of L. pneumophila were complemented by the expression E. coli trkD/Kup gene in trans, a bona fide K+ transporter encoded by E. coli. Collectively, our data indicate that KupA is a functional K+ transporter expressed by L. pneumophila that facilitates the bacterial replication intracellularly and in nutrient-limited conditions. PMID:23848378

  6. Identification and functional characterization of K(+) transporters encoded by Legionella pneumophila kup genes.

    Science.gov (United States)

    Hori, Juliana I; Pereira, Marcelo S F; Roy, Craig R; Nagai, Hiroki; Zamboni, Dario S

    2013-12-01

    Legionnaires' disease is an emerging, severe, pneumonia-like illness caused by the Gram-negative intracellular bacteria Legionella pneumophila, which are able to infect and replicate intracellularly in macrophages. Little is known regarding the mechanisms used by intracellular L. pneumophila for the acquisition of specific nutrients that are essential for bacterial replication. Here, we investigate three L. pneumophila genes with high similarity to the Escherichia coli K(+) transporters. These three genes were expressed by L. pneumophila and have been designated kupA, kupB and kupC. Investigation using the L. pneumophila kup mutants revealed that kupA is involved in K(+) acquisition during axenic growth. The kupA mutants replicated efficiently in rich axenic media, but poorly in a chemically defined medium. The kupA mutants were defective in the recruitment of polyubiquitinated proteins to the Legionella-containing vacuole that is formed in macrophages and displayed an intracellular multiplication defect during the replication in Acanthamoeba castellanii and in mouse macrophages. We found that bafilomycin treatment of macrophages was able to rescue the growth defects of kupA mutants, but itdid not influence the replication of wild-type bacteria. The defects identified in kupA mutants of L. pneumophila were complemented by the expression E. coli trkD/Kup gene in trans, a bona fide K(+) transporter encoded by E. coli. Collectively, our data indicate that KupA is a functional K(+) transporter expressed by L. pneumophila that facilitates the bacterial replication intracellularly and in nutrient-limited conditions.

  7. Isolation and functional characterization of CsLsi1, a silicon transporter gene in Cucumis sativus.

    Science.gov (United States)

    Sun, Hao; Guo, Jia; Duan, Yaoke; Zhang, Tiantian; Huo, Heqiang; Gong, Haijun

    2017-02-01

    Cucumber (Cucumis sativus) is a widely grown cucurbitaceous vegetable that exhibits a relatively high capacity for silicon (Si) accumulation, but the molecular mechanism for silicon uptake remains to be clarified. Here we isolated and characterized CsLsi1, a gene encoding a silicon transporter in cucumber (cv. Mch-4). CsLsi1 shares 55.70 and 90.63% homology with the Lsi1s of a monocot and dicot, rice (Oryza sativa) and pumpkin (Cucurbita moschata), respectively. CsLsi1 was predominantly expressed in the roots, and application of exogenous silicon suppressed its expression. Transient expression in cucumber protoplasts showed that CsLsi1 was localized in the plasma membrane. Heterologous expression in Xenopus laevis oocytes showed that CsLsi1 evidenced influx transport activity for silicon but not urea or glycerol. Expression of cucumber CsLsi1-mGFP under its own promoter showed that CsLsi1 was localized at the distal side of the endodermis and the cortical cells in the root tips as well as in the root hairs near the root tips. Heterologous expression of CsLsi1 in a rice mutant defective in silicon uptake and the over-expression of this gene in cucumber further confirmed the role of CsLsi1 in silicon uptake. Our results suggest that CsLsi1 is a silicon influx transporter in cucumber. The cellular localization of CsLsi1 in cucumber roots is different from that in other plants, implying the possible effect of transporter localization on silicon uptake capability.

  8. Expression pattern of peptide and amino acid genes in digestive tract of transporter juvenile turbot ( Scophthalmus maximus L.)

    Science.gov (United States)

    Xu, Dandan; He, Gen; Mai, Kangsen; Zhou, Huihui; Xu, Wei; Song, Fei

    2016-04-01

    Turbot ( Scophthalmus maximus L.), a carnivorous fish species with high dietary protein requirement, was chosen to examine the expression pattern of peptide and amino acid transporter genes along its digestive tract which was divided into six segments including stomach, pyloric caeca, rectum, and three equal parts of the remainder of the intestine. The results showed that the expression of two peptide and eleven amino acid transporters genes exhibited distinct patterns. Peptide transporter 1 (PepT1) was rich in proximal intestine while peptide transporter 2 (PepT2) was abundant in distal intestine. A number of neutral and cationic amino acid transporters expressed richly in whole intestine including B0-type amino acid transporter 1 (B0AT1), L-type amino acid transporter 2 (LAT2), T-type amino acid transporter 1 (TAT1), proton-coupled amino acid transporter 1 (PAT1), y+L-type amino acid transporter 1 (y+LAT1), and cationic amino acid transporter 2 (CAT2) while ASC amino acid transporter 2 (ASCT2), sodium-coupled neutral amino acid transporter 2 (SNAT2), and y+L-type amino acid transporter 2 (y+LAT2) abundantly expressed in stomach. In addition, system b0,+ transporters (rBAT and b0,+AT) existed richly in distal intestine. These findings comprehensively characterized the distribution of solute carrier family proteins, which revealed the relative importance of peptide and amino acid absorption through luminal membrane. Our findings are helpful to understand the mechanism of the utilization of dietary protein in fish with a short digestive tract.

  9. Gene Structure and Expression of the High-affinity Nitrate Transport System in Rice Roots

    Institute of Scientific and Technical Information of China (English)

    Chao Cai; Jun-Yi Wang; Yong-Guan Zhu; Qi-Rong Shen; Bin Li; Yi-Ping Tong; Zhen-Sheng Li

    2008-01-01

    Rice has a preference for uptake of ammonium over nitrate and can use ammonium-N efficiently. Consequently, transporters mediating ammonium uptake have been extensively studied, but nitrate transporters have been largely ignored. Recently,some reports have shown that rice also has high capacity to acquire nitrate from growth medium, so understanding the nitrate transport system in rice roots is very important for improving N use efficiency in rice. The present study identified four putative NRT2 and two putative NAR2 genes that encode components of the high-affinity nitrate transport system (HATS) in the rice (Oryza sativa L. subsp, japonica cv. Nipponbare) genome. OsNRT2.1 and OsNRT2.2 share an identical coding region sequence, and their deduced proteins are closely related to those from monocotyledonous plants. The two NAR2 proteins are closely related to those from mono-cotyledonous plants as well. However, OsNRT2.3 and OsNRT2.4 are more closely related to Arabidopsis NRT2 proteins. Relative quantitative reverse tranecdption-polymerase chain reaction analysis showed that all of the six genes were rapidly upregulated and then downregulated in the roots of N-starved rice plants after they were re-supplied with 0.2 mM nitrate, but the response to nitrate differed among gene members.The results from phylogenetic tree, gene structure and expression analysis implied the divergent roles for the individual members of the rice NRT2 and NAR2 families. High-affinity nitrate influx rates associated with nitrate induction in rice roots were investigated and were found to be regulated by external pH. Compared with the nitrate influx rates at pH 6.5, alkaline pH (pH 8.0) inhibited nitrate Influx, and acidic pH (pH 5.0) enhanced the nitrate influx In I h nitrate induced roots, but did not significantly affect that in 4 to 8 h nitrate induced roots.

  10. Bcmfs1, a novel major facilitator superfamily transporter from Botrytis cinerea, provides tolerance towards the natural toxic compounds camptothecin and cercosporin and towards fungicides.

    Science.gov (United States)

    Hayashi, Keisuke; Schoonbeek, Henk-Jan; De Waard, Maarten A

    2002-10-01

    Bcmfs1, a novel major facilitator superfamily gene from Botrytis cinerea, was cloned, and replacement and overexpression mutants were constructed to study its function. Replacement mutants showed increased sensitivity to the natural toxic compounds camptothecin and cercosporin, produced by the plant Camptotheca acuminata and the plant pathogenic fungus Cercospora kikuchii, respectively. Overexpression mutants displayed decreased sensitivity to these compounds and to structurally unrelated fungicides, such as sterol demethylation inhibitors (DMIs). A double-replacement mutant of Bcmfs1 and the ATP-binding cassette (ABC) transporter gene BcatrD was more sensitive to DMI fungicides than a single-replacement mutant of BcatrD, known to encode an important ABC transporter of DMIs. The sensitivity of the wild-type strain and mutants to DMI fungicides correlated with Bcmfs1 expression levels and with the initial accumulation of oxpoconazole by germlings of these isolates. The results indicate that Bcmfs1 is a major facilitator superfamily multidrug transporter involved in protection against natural toxins and fungicides and has a substrate specificity that overlaps with the ABC transporter BcatrD. Bcmfs1 may be involved in protection of B. cinerea against plant defense compounds during the pathogenic phase of growth on host plants and against fungitoxic antimicrobial metabolites during its saprophytic phase of growth.

  11. The serotonin transporter gene polymorphism 5-HTTLPR moderates the effects of stress on attention-deficit/hyperactivity disorder

    NARCIS (Netherlands)

    van der Meer, Dennis; Hartman, Catharina A.; Richards, Jennifer; Bralten, Janita B.; Franke, Barbara; Oosterlaan, Jaap; Heslenfeld, Dirk J.; Faraone, Stephen V.; Buitelaar, Jan K.; Hoekstra, Pieter J.

    2014-01-01

    IntroductionThe role of the serotonin transporter gene polymorphism 5-HTTLPR in attention-deficit/hyperactivity disorder (ADHD) is unclear. Heterogeneity of findings may be explained by gene-environment interactions (GxE), as it has been suggested that S-allele carriers are more reactive to psychoso

  12. Optimization of Intracellular Transportation of Gene Therapeutic DNA in Small Cell Lung Cancer (Ph.d.)

    DEFF Research Database (Denmark)

    Cramer, Frederik

    2013-01-01

    Small cell lung cancer (SCLC) is a highly malignant disease characterized as being very aggressive and metastasizing at a rapid pace. The malevolent pace of SCLC cell migration results in almost three out of four SCLC patients having disseminated SCLC at the time of diagnosis. Unfortunately...... and thereby improving the efficacy of the treatment. By implementing what is known as a DNA nuclear targeting sequence (DTS) strategy, we found that we could utilize the SCLC cells own transportation system thereby manipulating the cancer cells to bring our therapeutic plasmids from the cytoplasm......, there are currently no satisfactory treatments for SCLC and the prognosis is poor. New treatments are therefore in high demand and one such could potentially be gene therapy. However, curing a metastasizing disease such as SCLC by gene therapy requires a systemically applied delivery system. Such a delivery system...

  13. Serotonin transporter gene polymorphisms in patients with chronic tension-type headache: A preliminary study

    Directory of Open Access Journals (Sweden)

    Akcali Aylin

    2008-01-01

    Full Text Available Background and Objectives: This study is designed to understand the pathophysiology of one of the most serious health problems, chronic tension-type headache (CTTH. Two polymorphic sites in serotonin transporter protein gene attracted much interest. These are: the variable number of tandem repeats (VNTR and 5′-flanking promoter region (5-HTTLPR. Materials and Methods: VNTR and 5-HTTLPR polymorphisms were investigated in 126 CTTH patients and 138 healthy control subjects. The patients were being treated with amitripytyline or citalopram or sertraline (SSRI. The polymerase chain reaction (PCR method was used to investigate the polymorphisms in the serotonin transporter protein gene. Results: There were no statistically significant results based on the 5-HTTLPR gene alleles, however, STin 2.12/12 genotype and STin 2.12 allele were seen to predominate the control group. In order to investigate the combined effect of the two polymorphic loci on the 5-HTT gene expression, samples were separated into nine groups. Genotypes (S/S-12/10 and (L/S-12/10 displayed statistically significant frequency in the CTTH group than in the control group. No significant differences were noticed between the 5-HTTLPR and VNTR haplotype groups and success in treatment. Conclusion: It is possible to make reliable comparisons and hypothesis about the homozygous and/or heterozygous presence of S and STin 12/10 alleles which may be in interaction with CTTH. On the other hand, the presence of homozygous L and STin12 alleles may play a protective role against CTTH. It is also possible that heterogeneity among diseases showing the same clinical research will require a lot of effort for individual identification.

  14. The riboflavin transporter RibU in Lactococcus lactis : Molecular characterization of gene expression and the transport mechanism

    NARCIS (Netherlands)

    Burgess, CM; Slotboom, DJ; Geertsma, ER; Duurkens, Hinderika; Poolman, B; van Sinderen, D

    2006-01-01

    This study describes the characterization of the riboflavin transport protein RibU in the lactic acid bacterium Lactococcus lactis subsp. cremoris NZ9000. RibU is predicted to contain five membrane-spanning segments and is a member of a novel transport protein family, not described in the Transport

  15. Nurr1 enhances transcription of the human dopamine transporter gene through a novel mechanism.

    Science.gov (United States)

    Sacchetti, P; Mitchell, T R; Granneman, J G; Bannon, M J

    2001-03-01

    The importance of the nuclear receptor nurr1 for the appropriate development of mesencephalic dopamine-synthesizing neurons has been clearly demonstrated through the targeted disruption of the nurr1 gene. The persistence of nurr1 expression in adult tissue suggests a possible role for this transcription factor in the maintenance, as well as development, of the dopaminergic phenotype. To address this issue, we analyzed the effects of nurr1 on the transcriptional expression of the human dopamine transporter gene (hDAT), one of the most specific phenotypic markers for dopaminergic neurons. Nurr1 enhanced the transcriptional activity of hDAT gene constructs transiently transfected into a newly described cell line (SN4741) that expresses a dopaminergic phenotype, whereas other members of the NGFI-B subfamily of nuclear receptors had lesser or no effects. Nurr1 activation of hDAT was not dependent upon heterodimerization with the retinoid X receptor. Unexpectedly, functional analysis of a series of gene constructs revealed that a region of the hDAT 5'-flanking sequence devoid of NGFI-B response element (NBRE)-like sites mediated nurr1 activation. Additional experiments using a nurr1 mutant construct suggest that nurr1 activates hDAT transcription via a novel NBRE-independent mechanism.

  16. A New Activity-Based Cost (ABC) Mathematical Model

    Institute of Scientific and Technical Information of China (English)

    JIANG Shuo; SONG Lei

    2003-01-01

    Along with the product price competition growing intensely, it is apparently important for reasonably distributing and counting cost. But, in sharing indirect cost, traditional cost accounting unveils the limitations increasingly, especially in authenticity of cost information. And the accounting theory circles and industry circles begin seeking one kind of new accurate cost calculation method, and the activity-based cost (ABC) method emerges as the times require. In this paper, we will build its mathematical model by the basic principle of ABC, and will improve its mathematical model further. We will establish its comparison mathematical model and make the ABC method go a step further to its practical application.

  17. RirA is the iron response regulator of the rhizobactin 1021 biosynthesis and transport genes in Sinorhizobium meliloti 2011.

    Science.gov (United States)

    Viguier, Caroline; O Cuív, Páraic; Clarke, Paul; O'Connell, Michael

    2005-05-15

    The genes encoding the biosynthesis and transport of rhizobactin 1021, a siderophore produced by Sinorhizobium meliloti, are negatively regulated by iron. Mutagenesis of rirA, the rhizobial iron regulator, resulted in abolition of the iron responsive regulation of the biosynthesis and transport genes. Bioassay analysis revealed that the siderophore is produced in the presence of iron in a rirA mutant. RNA analysis and GFP fusions supported the conclusion that RirA is the mediator of iron-responsive transcriptional repression of the two transcripts encoding the biosynthesis and transport genes. RirA in S. meliloti appears to fulfil the role often observed for Fur in other bacterial species. The regulator was found to mediate the iron-responsive expression of two additional genes, smc02726 and dppA1, repressing the former while activating the latter. The rirA mutant nodulated the host plant Medicago sativa (alfalfa) and fixed nitrogen as effectively as the wild type.

  18. Complex polymorphisms in the Plasmodium falciparum multidrug resistance protein 2 gene and its contribution to antimalarial response.

    Science.gov (United States)

    Veiga, Maria Isabel; Osório, Nuno S; Ferreira, Pedro Eduardo; Franzén, Oscar; Dahlstrom, Sabina; Lum, J Koji; Nosten, Francois; Gil, José Pedro

    2014-12-01

    Plasmodium falciparum has the capacity to escape the actions of essentially all antimalarial drugs. ATP-binding cassette (ABC) transporter proteins are known to cause multidrug resistance in a large range of organisms, including the Apicomplexa parasites. P. falciparum genome analysis has revealed two genes coding for the multidrug resistance protein (MRP) type of ABC transporters: Pfmrp1, previously associated with decreased parasite drug susceptibility, and the poorly studied Pfmrp2. The role of Pfmrp2 polymorphisms in modulating sensitivity to antimalarial drugs has not been established. We herein report a comprehensive account of the Pfmrp2 genetic variability in 46 isolates from Thailand. A notably high frequency of 2.8 single nucleotide polymorphisms (SNPs)/kb was identified for this gene, including some novel SNPs. Additionally, we found that Pfmrp2 harbors a significant number of microindels, some previously not reported. We also investigated the potential association of the identified Pfmrp2 polymorphisms with altered in vitro susceptibility to several antimalarials used in artemisinin-based combination therapy and with parasite clearance time. Association analysis suggested Pfmrp2 polymorphisms modulate the parasite's in vitro response to quinoline antimalarials, including chloroquine, piperaquine, and mefloquine, and association with in vivo parasite clearance. In conclusion, our study reveals that the Pfmrp2 gene is the most diverse ABC transporter known in P. falciparum with a potential role in antimalarial drug resistance.

  19. The ABCs of molecular dynamics simulations on B-DNA, circa 2012

    Indian Academy of Sciences (India)

    David L Beveridge; Thomas E Cheatham III; Mihaly Mezei

    2012-07-01

    This article provides a retrospective on the ABC initiative in the area of all-atom molecular dynamics (MD) simulations including explicit solvent on all tetranucleotide steps of duplex B-form DNA duplex, ca. 2012. The ABC consortium has completed two phases of simulations, the most current being a set of 50–100 trajectories based on the AMBER ff99 force field together with the parmbsc0 modification. Some general perspectives on the field of MD on DNA and sequence effects on DNA structure are provided, followed by an overview our MD results, including a detailed comparison of the ff99/parmbsc0 results with crystal and NMR structures available for d(CGCGAATTCGCG). Some projects inspired by or related to the ABC initiative and database are also reviewed, including methods for the trajectory analyses, informatics of dealing with the large database of results, compressions of trajectories for efficacy of distribution, DNA solvation by water and ions, parameterization of coarse-grained models with applications and gene finding and genome annotation

  20. Functional characterization of a potassium transporter geneNrHAK1 in Nicotiana rustica

    Institute of Scientific and Technical Information of China (English)

    Zhao-kui GUO; Qian YANG; Xiu-qing WAN; Pei-qiang YAN

    2008-01-01

    The purpose of this study is to investigate the function of a novel potassium transporter gene(NrHAK1) isolated from Nicotiana rustica roots using yeast complement and real-time PCR technique. The complementary DNA (cDNA) of NrHAK1, 2 488 bp long, contains an open reading frame (ORF) of 2334 bp encoding a protein of 777 amino acids (87.6 kDa) with 12 predicted transmembrane domains. The NrHAK1 protein shows a high sequence similarity to those of high-affinity potassium transporters in Mesembryanthemum, Phytolacca acinosa, Arabidopsis thaliana, and so on. We found that the NrHAK1 gene could complement the yeast-mutant defect in K+ uptake. Among several tissues surveyed, the expression level of NrHAK1 was most abundant in the root tip and was up-regulated when exposed to potassium starvation. Moreover, the transcript accumulation was significantly reduced by adding 5 mmol/L NH4 to the solution. These results suggest that NrHAK1 plays an important role in potassium absorption in N. Rustica.

  1. UDP-galactose and acetyl-CoA transporters as Plasmodium multidrug resistance genes.

    Science.gov (United States)

    Lim, Michelle Yi-Xiu; LaMonte, Gregory; Lee, Marcus C S; Reimer, Christin; Tan, Bee Huat; Corey, Victoria; Tjahjadi, Bianca F; Chua, Adeline; Nachon, Marie; Wintjens, René; Gedeck, Peter; Malleret, Benoit; Renia, Laurent; Bonamy, Ghislain M C; Ho, Paul Chi-Lui; Yeung, Bryan K S; Chow, Eric D; Lim, Liting; Fidock, David A; Diagana, Thierry T; Winzeler, Elizabeth A; Bifani, Pablo

    2016-01-01

    A molecular understanding of drug resistance mechanisms enables surveillance of the effectiveness of new antimicrobial therapies during development and deployment in the field. We used conventional drug resistance selection as well as a regime of limiting dilution at early stages of drug treatment to probe two antimalarial imidazolopiperazines, KAF156 and GNF179. The latter approach permits the isolation of low-fitness mutants that might otherwise be out-competed during selection. Whole-genome sequencing of 24 independently derived resistant Plasmodium falciparum clones revealed four parasites with mutations in the known cyclic amine resistance locus (pfcarl) and a further 20 with mutations in two previously unreported P. falciparum drug resistance genes, an acetyl-CoA transporter (pfact) and a UDP-galactose transporter (pfugt). Mutations were validated both in vitro by CRISPR editing in P. falciparum and in vivo by evolution of resistant Plasmodium berghei mutants. Both PfACT and PfUGT were localized to the endoplasmic reticulum by fluorescence microscopy. As mutations in pfact and pfugt conveyed resistance against additional unrelated chemical scaffolds, these genes are probably involved in broad mechanisms of antimalarial drug resistance.

  2. Blood-brain barrier transport of non-viral gene and RNAi therapeutics.

    Science.gov (United States)

    Boado, Ruben J

    2007-09-01

    The development of gene- and RNA interference (RNAi)-based therapeutics represents a challenge for the drug delivery field. The global brain distribution of DNA genes, as well as the targeting of specific regions of the brain, is even more complicated because conventional delivery systems, i.e. viruses, have poor diffusion in brain when injected in situ and do not cross the blood-brain barrier (BBB), which is only permeable to lipophilic molecules of less than 400 Da. Recent advances in the "Trojan Horse Liposome" (THL) technology applied to the transvascular non-viral gene therapy of brain disorders presents a promising solution to the DNA/RNAi delivery obstacle. The THL is comprised of immunoliposomes carrying either a gene for protein replacement or small hairpin RNA (shRNA) expression plasmids for RNAi effect, respectively. The THL is engineered with known lipids containing polyethyleneglycol (PEG), which stabilizes its structure in vivo in circulation. The tissue target specificity of THL is given by conjugation of approximately 1% of the PEG residues to peptidomimetic monoclonal antibodies (MAb) that bind to specific endogenous receptors (i.e. insulin and transferrin receptors) located on both the BBB and the brain cellular membranes, respectively. These MAbs mediate (a) receptor-mediated transcytosis of the THL complex through the BBB, (b) endocytosis into brain cells and (c) transport to the brain cell nuclear compartment. The present review presents an overview of the THL technology and its current application to gene therapy and RNAi, including experimental models of Parkinson's disease and brain tumors.

  3. Intraflagellar transport gene expression associated with short cilia in smoking and COPD.

    Directory of Open Access Journals (Sweden)

    Justina Hessel

    Full Text Available Smoking and COPD are associated with decreased mucociliary clearance, and healthy smokers have shorter cilia in the large airway than nonsmokers. We hypothesized that changes in cilia length are consistent throughout the airway, and we further hypothesized that smokers with COPD have shorter cilia than healthy smokers. Because intraflagellar transport (IFT is the process by which cilia of normal length are produced and maintained, and alterations in IFT lead to short cilia in model organisms, we also hypothesized that smoking induces changes in the expression of IFT-related genes in the airway epithelium of smokers and smokers with COPD. To assess these hypotheses, airway epithelium was obtained via bronchoscopic brushing. Cilia length was assessed by measuring 100 cilia (10 cilia on each of 10 cells per subject and Affymetrix microarrays were used to evaluate IFT gene expression in nonsmokers and healthy smokers in 2 independent data sets from large and small airway as well as in COPD smokers in a data set from the small airway. In the large and small airway epithelium, cilia were significantly shorter in healthy smokers than nonsmokers, and significantly shorter in COPD smokers than in both healthy smokers and nonsmokers. The gene expression data confirmed that a set of 8 IFT genes were down-regulated in smokers in both data sets; however, no differences were seen in COPD smokers compared to healthy smokers. These results support the concept that loss of cilia length contributes to defective mucociliary clearance in COPD, and that smoking-induced changes in expression of IFT genes may be one mechanism of abnormally short cilia in smokers. Strategies to normalize cilia length may be an important avenue for novel COPD therapies.

  4. Examination of the nature of the ABC effect

    Science.gov (United States)

    Bashkanov, M.; Clement, H.; Skorodko, T.

    2017-02-01

    Recently it has been shown by exclusive and kinematically complete experiments that the appearance of a narrow resonance structure in double-pionic fusion reactions is strictly correlated with the appearance of the so-called ABC effect, which denotes a pronounced low-mass enhancement in the ππ-invariant mass spectrum. Whereas the resonance structure got its explanation by the d* (2380) dibaryonic resonance, a satisfactory explanation for the ABC effect is still pending. In this paper we discuss possible explanations of the ABC effect and their consequences for the internal structure of the d* dibaryon. To this end we examine and review a variety of proposed explanations for the ABC effect, add a new hypothesis and confront all of them with the experimental results for the np → dπ0π0 and np → npπ0π0 reactions, which are the most challenging ones for this topic.

  5. Yang-Mills Theory and the ABC Conjecture

    CERN Document Server

    He, Yang-Hui; Probst, Malte; Read, James

    2016-01-01

    We establish a precise correspondence between the ABC Conjecture and N=4 super-Yang-Mills theory. This is achieved by combining three ingredients: (i) Elkies' method of mapping ABC-triples to elliptic curves in his demonstration that ABC implies Mordell/Faltings; (ii) an explicit pair of elliptic curve and associated Belyi map given by Khadjavi-Scharaschkin; and (iii) the fact that the bipartite brane-tiling/dimer model for a gauge theory with toric moduli space is a particular dessin d'enfant in the sense of Grothendieck. We explore this correspondence for the highest quality ABC-triples as well as large samples of random triples. The Conjecture itself is mapped to a statement about the fundamental domain of the toroidal compactification of the string realization of N=4 SYM.

  6. Multicompartment Micelles From π-Shaped ABC Block Copolymers

    Institute of Scientific and Technical Information of China (English)

    XIA Jun; ZHONG Chong-Li

    2007-01-01

    Dissipative particle dynamics simulations were performed on the morphology and structure of multicompartment micelles formed from n-shaped ABC block copolymers in water. The influences of chain architectures were studied in a systematic way, and a rich variety of morphologies were observed, such as spherical, wormlike,X-shaped, Y-shaped, ribbon-like, layered rod-like, layered disk-like, as well as network morphologies. The simulations show that the distance between the two grafts plays an important role in control of the morphology. Since π-shaped ABC block copolymers can be reduced to linear ABC and star ABC block copolymers, they are good model copolymers for studying the self-assembly of complex block copolymers into micelles. The knowledge obtained in this work as well as the new morphologies identified provide useful information for future rational design and synthesis of novel multicompartment micelles.

  7. abc: An Extensible AspectJ Compiler

    DEFF Research Database (Denmark)

    Avgustinov, Pavel; Christensen, Aske Simon; Hendren, Laurie J.;

    2006-01-01

    Research in the design of aspect-oriented programming languages requires a workbench that facilitates easy experimentation with new language features and implementation techniques. In particular, new features for AspectJ have been proposed that require extensions in many dimensions: syntax, type...... language. The use of Polyglot gives flexibility of syntax and type checking. The back end is built using the Soot framework, to give modular code generation and analyses. In this paper, we outline the design of abc, focusing mostly on how the design supports extensibility. We then provide a general...... overview of how to use abc to implement an extension. We illustrate the extension mechanisms of abc through a number of small, but nontrivial, examples. We then proceed to contrast the design goals of abc with those of the original AspectJ compiler, and how these different goals have led to different...

  8. Redundancy Level Optimization in Modular Software System Models using ABC

    Directory of Open Access Journals (Sweden)

    Tarun Kumar Sharma

    2014-03-01

    Full Text Available The performance of optimization algorithms is problem dependent and as per no free lunch theorem, there exists no such algorithm which can be efficiently applied to every type of problem(s. However, we can modify the algorithm/ technique in a manner such that it is able to deal with a maximum type of problems. In this study we have modified the structure of basic Artificial Bee Colony (ABC, a recently proposed metaheuristic algorithm based on the concept of swarm intelligence to optimize the models of software reliability. The modified variant of ABC is termed as balanced ABC (B-ABC. The simulated results show the efficiency and capability of the variant to solve such type of the problems.

  9. The Role of ABC Proteins in Drug Resistant Breast Cancer Cells

    Science.gov (United States)

    2008-04-01

    F-æ80lacZ∆M15 ∆(lacZYA-argF)U169 recA1 endA1 hsdR17(rk-, mk +) phoA supE44 thi-1 gyrA96 relA1 λ-) was used for all routine subcloning work. Pichia...multidrug transport activities of the overexpressed yeast ABC protein Yor1p, J. Biol. Chem. 273, 12612-12622. 28. Shukla , S., Rai, V., Banerjee, D., and

  10. Gene : CBRC-CREM-01-1327 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-CREM-01-1327 Novel UN C UNKNOWN BCH2_RHOCA 0.12 27% ref|YP_705999.1| possible ABC antibiotics... transporter [Rhodococcus sp. RHA1] gb|ABG97841.1| possible ABC antibiotics transporter [Rhod

  11. Nuclear factor-κB regulates the expression of multiple genes encoding liver transport proteins.

    Science.gov (United States)

    Balasubramaniyan, Natarajan; Ananthanarayanan, Meenakshisundaram; Suchy, Frederick J

    2016-04-15

    In this study we identified the mechanisms underlying the inhibitory effects of NF-κB on the expression of genes encoding multiple liver transport proteins. Well-conserved NF-κB binding sites were found in the promoters of farnesoid X receptor (FXR)-target genes. An electromobility shift assay (EMSA) demonstrated the specific interaction between the NF-κB p65 protein and a (32)P-labeled BSEP NF-κB response element (NF-κBE). Chromatin immunoprecipitation (ChIP) analysis confirmed binding of NF-κB p65 to the BSEP locus but not the FXRE in vitro. NF-κB p65 overexpression in Huh-7 cells markedly repressed FXR/RXR transactivation of the BSEP, ABCG5/G8, MRP2, and FXR promoters, which was totally reversed by expression of the IκBα super-repressor. NF-κB interacted directly with FXR on coimmunoprecipitation, suggesting another level for the inhibitory effects of NF-κB on FXR-target genes. In vivo ChIP analysis with liver nuclei obtained from mice after 3 days of common bile duct ligation (BDL) or 6 h post-lipopolysaccharide (LPS) injection showed a markedly increased recruitment of NF-κB p65 to the Bsep promoter compared with controls. There was also increased recruitment of the corepressor silencing mediator of retinoic acid and thyroid hormone receptor (SMRT) and histone deacetylase (HDAC)3 and HDAC2 to the NF-κB sites. We also found that NF-κB p65 was recruited to NF-κB binding sites in the promoters of organic solute transporter, OSTα and OSTβ, and unexpectedly activated rather than repressed gene expression. In mouse liver after BDL NF-κB recruitment to Ostα and Ostβ promoters was associated with increased binding of the potent coactivator cAMP response element binding protein (CREB)-binding protein (CBP)/p300 to the NF-κBE and depletion of CBP/p300 at the FXR element. Overall, these studies demonstrate a novel role for NF-κB in adaptation to obstructive and LPS-induced cholestasis acting through recruitment to specific NF-κB binding sites in

  12. Oxytocin receptor (OXTR) and serotonin transporter (5-HTT) genes associated with observed parenting.

    Science.gov (United States)

    Bakermans-Kranenburg, Marian J; van Ijzendoorn, Marinus H

    2008-06-01

    Both oxytocin and serotonin modulate affiliative responses to partners and offspring. Animal studies suggest a crucial role of oxytocin in mammalian parturition and lactation but also in parenting and social interactions with offspring. The serotonergic system may also be important through its influence on mood and the release of oxytocin. We examined the role of serotonin transporter (5-HTT) and oxytocin receptor (OXTR) genes in explaining differences in sensitive parenting in a community sample of 159 Caucasian, middle-class mothers with their 2-year-old toddlers at risk for externalizing behavior problems, taking into account maternal educational level, maternal depression and the quality of the marital relationship. Independent genetic effects of 5-HTTLPR SCL6A4 and OXTR rs53576 on observed maternal sensitivity were found. Controlling for differences in maternal education, depression and marital discord, parents with the possibly less efficient variants of the serotonergic (5-HTT ss) and oxytonergic (AA/AG) system genes showed lower levels of sensitive responsiveness to their toddlers. Two-way and three-way interactions with marital discord or depression were not significant. This first study on the role of both OXTR and 5-HTT genes in human parenting points to molecular genetic differences that may be implicated in the production of oxytocin explaining differences in sensitive parenting.

  13. Functional Characterization of a Putative Nitrate Transporter Gene Promoter from Rice

    Institute of Scientific and Technical Information of China (English)

    Ting-Zhang HU; Kai-Ming CAO; Mian XIA; Xi-Ping WANG

    2006-01-01

    Drought is one of the most significant abiotic stresses that influence plant growth and development. Expression analysis revealed that OsNRT1.3, a putative nitrate transporter gene in rice, was induced by drought. To confirm if the OsNRT1.3 promoter can respond to drought stress, a 2019 bp upstream sequence of OsNRT1.3 was cloned. Three OsNRT1.3 promoter fragments were generated by 5'-deletion, and fused to the β-glucuronidase (GUS) gene. The chimeric genes were introduced into rice plants. NRT2019::GUS, NRT1196: :GUS and NRT719::GUS showed similar expression patterns in seeds,roots, leaves and flowers in all transgenic rice, and GUS activity conferred by different OsNRT1.3 promoter fragments was significantly upregulated by drought stress, indicating that OsNRT1.3 promoter responds to drought stress and the 719 bp upstream sequence of OsNRT1.3 contains the drought response elements.

  14. Arsenate induces the expression of fungal genes involved in As transport in arbuscular mycorrhiza.

    Science.gov (United States)

    González-Chávez, Ma del Carmen A; Ortega-Larrocea, María del Pilar; Carrillo-González, Rogelio; López-Meyer, Melina; Xoconostle-Cázares, Beatriz; Gomez, Susana K; Harrison, Maria J; Figueroa-López, Alejandro Miguel; Maldonado-Mendoza, Ignacio E

    2011-12-01

    We utilized the two-compartment system to study the effect of arsenic (As) on the expression of the Glomus intraradices high-affinity phosphate transporter GiPT, and the GiArsA gene, a novel protein with a possible putative role as part of an arsenite efflux pump and similar to ArsA ATPase. Our results show that induction of GiPT expression correlates with As(V) uptake in the extra-radical mycelium of G. intraradices. We showed a time-concerted induction of transcript levels first of GiPT, followed by GiArsA, as well as the location of gene expression using laser microdissection of these two genes not only in the extra-radical mycelium but also in arbuscules. This work represents the first report showing the dissection of the molecular players involved in arbuscular mycorrhizal fungus (AMF)-mediated As tolerance in plants, and suggests that tolerance mediated by AMF may be caused by an As exclusion mechanism, where fungal structures such as the extra-radical mycelium and arbuscules may be playing an important role. Our results extend knowledge of the mechanisms underlying As efflux in arbuscular mycorrhizal fungi and mechanisms related to As tolerance.

  15. ABCE1 is a highly conserved RNA silencing suppressor.

    Directory of Open Access Journals (Sweden)

    Kairi Kärblane

    Full Text Available ATP-binding cassette sub-family E member 1 (ABCE1 is a highly conserved protein among eukaryotes and archaea. Recent studies have identified ABCE1 as a ribosome-recycling factor important for translation termination in mammalian cells, yeast and also archaea. Here we report another conserved function of ABCE1. We have previously described AtRLI2, the homolog of ABCE1 in the plant Arabidopsis thaliana, as an endogenous suppressor of RNA silencing. In this study we show that this function is conserved: human ABCE1 is able to suppress RNA silencing in Nicotiana benthamiana plants, in mammalian HEK293 cells and in the worm Caenorhabditis elegans. Using co-immunoprecipitation and mass spectrometry, we found a number of potential ABCE1-interacting proteins that might support its function as an endogenous suppressor of RNA interference. The interactor candidates are associated with epigenetic regulation, transcription, RNA processing and mRNA surveillance. In addition, one of the identified proteins is translin, which together with its binding partner TRAX supports RNA interference.

  16. Bacterial multidrug resistance mediated by a homologue of the human multidrug transporter P-glycoprotein

    NARCIS (Netherlands)

    Konings, WN; Poelarends, GJ

    2002-01-01

    Most ATP-binding cassette (ABC) multidrug transporters known to date are of eukaryotic origin, such as the P-glycoproteins (Pgps) and multidrug resistance-associated proteins (MRPs). Only one well-characterized ABC multidrug transporter, LmrA, is of bacterial origin. On the basis of its structural a

  17. Overexpression of a novel Arabidopsis gene related to putative zinc-transporter genes from animals can lead to enhanced zinc resistance and accumulation.

    Science.gov (United States)

    van der Zaal, B J; Neuteboom, L W; Pinas, J E; Chardonnens, A N; Schat, H; Verkleij, J A; Hooykaas, P J

    1999-03-01

    We describe the isolation of an Arabidopsis gene that is closely related to the animal ZnT genes (Zn transporter). The protein encoded by the ZAT (Zn transporter of Arabidopsis thaliana) gene has 398 amino acid residues and is predicted to have six membrane-spanning domains. To obtain evidence for the postulated function of the Arabidopsis gene, transgenic plants with the ZAT coding sequence under control of the cauliflower mosaic virus 35S promoter were analyzed. Plants obtained with ZAT in the sense orientation exhibited enhanced Zn resistance and strongly increased Zn content in the roots under high Zn exposure. Antisense mRNA-producing plants were viable, with a wild-type level of Zn resistance and content, like plants expressing a truncated coding sequence lacking the C-terminal cytoplasmic domain of the protein. The availability of ZAT can lead to a better understanding of the mechanism of Zn homeostasis and resistance in plants.

  18. mRNA levels of related Abcb genes change opposite to each other upon histone deacetylase inhibition in drug-resistant rat hepatoma cells.

    Directory of Open Access Journals (Sweden)

    Adám Sike

    Full Text Available The multidrug-resistant phenotype of tumor cells is acquired via an increased capability of drug efflux by ABC transporters and causes serious problems in cancer treatment. With the aim to uncover whether changes induced by epigenetic mechanisms in the expression level of drug transporter genes correlates with changes in the drug resistance phenotypes of resistant cells, we studied the expression of drug transporters in rat hepatoma cell lines. We found that of the three major rat ABC transporter genes Abcb1a, Abcb1b and Abcc1 the activity of only Abcb1b increased significantly in colchicine-selected, drug-resistant cells. Increased transporter expression in drug-resistant cells results primarily from transcriptional activation. A change in histone modification at the regulatory regions of the chromosomally adjacent Abcb1a and Abcb1b genes differentially affects the levels of corresponding mRNAs. Transcriptional up- and down-regulation accompany an increase in acetylation levels of histone H3 lysine 9 at the promoter regions of Abcb1b and Abcb1a, respectively. Drug efflux activity, however, does not follow tightly the transcriptional activity of drug transporter genes in hepatoma cells. Our results point out the need for careful analysis of cause-and-effect relationships between changes in histone modification, drug transporter expression and drug resistance phenotypes.

  19. Association of serotonin transporter promoter gene polymorphism (5-HTTLPR) with depression in Costa Rican schizophrenic patients.

    Science.gov (United States)

    Contreras, Javier; Hernández, Sandra; Quezada, Paulina; Dassori, Albana; Walss-Bass, Consuelo; Escamilla, Michael; Raventos, Henriette

    2010-07-01

    Depression and suicidal behavior are frequently observed in patients with schizophrenia. The serotonin transporter protein regulates serotonergic signaling at synapses and is encoded by a single gene (SLC6A4; Locus Link ID: 6532), located at 17q11.1-q12 with two polymorphic variants (the short and the long allele). The short allele of serotonin transporter gene has been associated with depression and suicidality in individuals who suffered negative life events and with depression in individuals with chronic psychosis.. Subjects were recruited from a genetic study of schizophrenia conducted in Costa Rica. The authors replicated their previous research, using a more narrow phenotype (only schizophrenic subjects) and a more ethnically homogenous sample (only Costa Rican schizophrenic individuals who were not included in the previous study). The authors hypothesized that subjects with at least one copy of the serotonin transporter promoter gene polymorphism (5-HTTLPR) "s" allele would have a greater history of lifetime depression and suicidability rate than those who had an "l/l" genotype. The authors analyzed 155 subjects with a DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) diagnosis of schizophrenia (73% male, age at interview 38.3, SD = 11.23). The genotype distribution was "ss" 58 (37%), "sl" 69 (45%), and "ll" 28 (18%). In the secondary analysis, the authors explored association of the "s" allele with lifetime history of suicide behavior in 173 subjects (18 more subjects than primary analysis because schizophrenic individuals were included regardless of history of depression). The authors found that subjects carrying at least one short allele had a significant increased lifetime risk for depressive syndromes (chi(2) = 5.4, df = 1, P = 0.02; odds ratio [OR] = 2.7, 95% confidence interval [CI] = 1.15-6.3). No association was found for suicidal behavior in the same sample (chi(2) = 0.928, P = 0.629). In conclusion, the genotype at the

  20. ArgR-dependent repression of arginine and histidine transport genes in Escherichia coli K-12.

    Science.gov (United States)

    Caldara, Marina; Minh, Phu Nguyen Le; Bostoen, Sophie; Massant, Jan; Charlier, Daniel

    2007-10-19

    In Escherichia coli L-arginine is taken up by three periplasmic binding protein-dependent transport systems that are encoded by two genetic loci: the artPIQM-artJ and argT-hisJQMP gene clusters. The transcription of the artJ, artPIQM and hisJQMP genes and operons is repressed by liganded ArgR, whereas argT, encoding the LAO (lysine, arginine, ornithine) periplasmic binding protein, is insensitive to the repressor. Here we characterize the repressible Esigma70 P artJ, P artP and P hisJ promoters and demonstrate that the cognate operators consist of two 18 bp ARG boxes separated by 3 bp. Determination of the energy landscape of the ArgR-operator contacts by missing contact probing and mutant studies indicated that each box of a pair contributes to complex formation in vitro and to the repressibility in vivo, but to a different extent. The organization of the ARG boxes and promoter elements in the control regions of the uptake genes is distinct from that of the arginine biosynthetic genes. The hisJQMP operon is the first member of the E. coli ArgR regulon, directly repressed by liganded ArgR, where none of the core promoter elements overlaps the ARG boxes. Single round in vitro transcription assays and DNase I footprinting experiments indicate that liganded ArgR inhibits P artJ and P artP promoter activity by steric exclusion of the RNA polymerase. In contrast, ArgR-mediated repression of P hisJ by inhibition of RNA polymerase binding appears to occur through topological changes of the promoter region.

  1. Identification of rare high-risk copy number variants affecting the dopamine transporter gene in mental disorders

    DEFF Research Database (Denmark)

    Hoeffding, Louise K; Duong, Linh T T; Ingason, Andrés;

    2015-01-01

    BACKGROUND: The dopamine transporter, also known as solute carrier 6A3 (SLC6A3), plays an important role in synaptic transmission by regulating the reuptake of dopamine in the synapses. In line with this, variations in the gene encoding this transporter have been linked to both schizophrenia...... rare high-risk variants of psychiatric disorders. METHODS: We performed a systematic screening for CNVs affecting SLC6A3 in 761 healthy controls, 672 schizophrenia patients, and 194 patients with bipolar disorder in addition to 253 family members from six large pedigrees affected by mental disorders...... sizes and two affected several genes in addition to SLC6A3. CONCLUSION: Our findings suggest that rare high-risk CNVs affecting the gene encoding the dopamine transporter contribute to the pathogenesis of schizophrenia and affective disorders....

  2. Effect of antisense transfecting of monocarboxylate transporter gene on biological characteristics of lung adenocarcinoma A549 cells

    Institute of Scientific and Technical Information of China (English)

    ZHANG Gui-zhi; HUANG Gui-jun; GUO Xian-jian; QIAN Gui-sheng

    2002-01-01

    Objective: To study the influence of transfecting antisense expression vector of the first subtype of the monocarboxylate transporter (MCT1) gene into lung cancer cells on pHi regulation, lactate transportation and cell growth, Methods: MCT1 antisense gene recombinant vector was introduced into human lung cancer cell line A549 by electroporation. The transfected A549 cells resistant to G418 were selected. Positive clones were examined by using PCR. The changes of intracellular pH and lactate were examined with spectrophotometric method. Cell growth was studied with cell growth curve. Results: Intracellular pH and lactate were remarkably decreased in the cells transfected pLXSN-MCT1 in comparison with A549 cells without transfection (P<0. 001). The growth of A549 cells transfected pLXSN-MCT1 was also inhibited remarkably. Conclusion: MCT1 gene may play an important role in pHi regulation, lactate transportation and cell growth in tumor cells.

  3. Expression of the Bcl-2 family genes and complexes involved in the mitochondrial transport in prostate cancer cells.

    Science.gov (United States)

    Asmarinah, Asmarinah; Paradowska-Dogan, Agnieszka; Kodariah, Ria; Tanuhardja, Budiana; Waliszewski, Przemyslaw; Mochtar, Chaidir Arif; Weidner, Wolfgang; Hinsch, Elvira

    2014-10-01

    Alteration of molecular pathways triggering apoptosis gives raise to various pathological tissue processes, such as tumorigenesis. The mitochondrial pathway is regulated by both the genes of the Bcl-2 family and the genes encoding mitochondrial transport molecules. Those proteins allow a release of cyctochrome c through the outer mitochondrial membrane. This release activates the caspase cascade resulting in death of cells. There are at least two main transport systems associated with the family of Bcl-2 proteins that are involved in transport of molecules through the outer mitochondrial membrane, i.e., the voltage dependent anion channels (VDACs) and translocases of the outer mitochondrial membrane proteins (TOMs). We investigated the expression of genes of the Bcl-2 family, i.e., pro-apoptotic Bak and Bid, and anti-apoptotic Bcl-2; VDAC gene, i.e., VDAC1, VDAC2 and VDAC3; and TOMM genes, i.e., TOMM20, TOMM22 and TOMM40. This study was performed at the mRNA and the protein level. Fourteen paraffin embedded prostate cancer tissues and five normal prostate tissues were analyzed by the quantitative PCR array and immunohistochemistry. We found a significant increase in both mRNA expression of the anti-apoptotic Bcl-2 gene and VDAC1 gene in prostate cancer tissue in comparison with their normal counterparts. Translation of the anti-apoptotic Bcl-2 and VDAC1 genes in prostate cancer tissue was slightly increased. We observed no significant differences in the mRNA expression of the pro-apoptotic Bak and Bid genes, VDAC2 or VDAC3 genes or the three TOMM genes in these tissues. The pro-apoptotic Bax protein was downtranslated significantly in secretory cells of prostate cancer as compared to normal prostate. We suggest that this protein is a good candidate as biomarker for prostate cancer.

  4. Short report: polymorphisms in the chloroquine resistance transporter gene in Plasmodium falciparum isolates from Lombok, Indonesia.

    Science.gov (United States)

    Huaman, Maria Cecilia; Yoshinaga, Kazumi; Suryanatha, Aan; Suarsana, Nyoman; Kanbara, Hiroji

    2004-07-01

    The polymorphisms in the Plasmodium falciparum multidrug resistance 1 (pfmdr1) and P. falciparum chloroquine resistance transporter (pfcrt) genes, which are associated with chloroquine resistance, were examined in 48 P. falciparum isolates from uncomplicated malaria patients from the West Lombok District in Indonesia. The point mutation N86Y in pfmdr1 was present in 35.4% of the isolates and mutation K76T in pfcrt was found in all but one of the samples studied. Identified pfcrt haplotypes were mainly identical to the Papua New Guinea type S(agt)VMNT (42 of 48, 87.5%), and a few isolates had the Southeast Asia type CVIET (5 of 48, 10.4%). Moreover, one P. falciparum isolate harbored the K76N mutation, giving rise to the haplotype CVMNN, which was not previously reported in field isolates. Our findings suggest that chloroquine resistance in this area might have the same origin as in Papua New Guinea.

  5. Metodologia ABC: implantação numa microempresa ABC methodology: implementation on a micro firm

    Directory of Open Access Journals (Sweden)

    Orlando Duran

    2000-08-01

    Full Text Available Este trabalho relata a implantação da metodologia de custos baseados em atividades numa microempresa do ramo metalúrgico. A proposta pretende demonstrar a viabilidade de aplicar esta técnica em empresas sem importar seu tamanho, só realizando algumas adaptações que garantam baixo investimento e curto espaço de tempo para obter os resultados. Na parte final do trabalho se realiza uma análise dos resultados obtidos verificando-se o potencial da informação gerada pela metodologia e seu uso como ferramenta de gestão.This paper presents an implementation of the activity based costing (ABC methodology in a small firm. The approach presented is intended to demonstrate the feasibility of applying the ABC methodology at any sized firm, only through few adaptations for ensuring low investments fees and speed in obtaining results and information from the system. Discussion about the results obtained during the implementation case are presented and the potential of using the information generated from the system as a managing tool is commented.

  6. The Malus domestica sugar transporter gene family: identifications based on genome and expression profiling related to the accumulation of fruit sugars

    OpenAIRE

    2014-01-01

    In plants, sugar transporters are involved not only in long-distance transport, but also in sugar accumulations in sink cells. To identify members of sugar transporter gene families and to analyze their function in fruit sugar accumulation, we conducted a phylogenetic analysis of the Malus domestica genome. Expression profiling was performed with shoot tips, mature leaves, and developed fruit of ‘Gala’ apple. Genes for sugar alcohol (including 17 sorbitol transporters), sucrose, and monosacch...

  7. Extensive inter-domain lateral gene transfer in the evolution of the human commensal Methanosphaera stadtmanae

    Directory of Open Access Journals (Sweden)

    Mor Nadia Lurie-Weinberger

    2012-09-01

    Full Text Available Methanosphaera stadtmanae is a commensal methanogenic archaeon found in the human gut. As most of its niche-neighbors are bacteria, it is expected that lateral gene transfer (LGT from bacteria might have contributed to the evolutionary history of this organism. We performed a phylogenomic survey of putative lateral gene transfer events in M. stadtmanae, using a phylogenetic pipeline. Our analysis indicates that a substantial fraction of the proteins of M. stadtmanae are inferred to have been involved in inter-domain LGT. Laterally acquired genes have had a large contribution to surface functions, by providing novel glycosyltransferase functions. In addition, several ABC transporters seem to be of bacterial origin, including the molybdate transporter. Thus, bacterial genes contributed to the adaptation of M. stadtmanae to a host dependent lifestyle by allowing a larger variation in surface structures and increasing transport efficiency in the gut niche which is diverse and competitive

  8. Transcriptional profiling of the PDR gene family in rice roots in response to plant growth regulators, redox perturbations and weak organic acid stresses.

    Science.gov (United States)

    Moons, Ann

    2008-12-01

    The role of plant pleiotropic drug resistance (PDR) type ATP-binding cassette (ABC) transporters remains poorly understood. We characterized the expression of the rice pleiotropic drug resistance (PDR) gene family in roots, where PDR transporters are believed to have major functions. A prototypical oligonucleotide array was developed containing 70-mers chosen in the gene-specific 3' untranslated regions of the rice PDR genes, other full-molecule rice ABC transporter genes and relevant marker genes. Jasmonates, which are involved in plant defense and secondary metabolism, proved major inducers of PDR gene expression. Over half of the PDR genes were JA-induced in roots of rice; OsPDR9 to the highest level. Salicylic acid, involved in plant pathogen defense, markedly induced the expression of OsPDR20. OsPDR20 was cDNA cloned and characterized. Abscisic acid, typically involved in water deficit responses, particularly induced OsPDR3 in roots and shoot and OsPDR6 in rice leaves. OsPDR9 and OsPDR20 were furthermore up-regulated in response to dithiothreitol- or glutathione-induced redox perturbations. Exogenous application of the weak organic acids lactic acid, malic acid, and citric acid differentially induced the expression of OsPDR3, OsPDR8, OsPDR9 and OsPDR20 in rice seedling roots. This transcriptional survey represents a guide for the further functional analysis of individual PDR transporters in roots of rice.

  9. P-glycoprotein in sheep liver and small intestine: gene expression and transport efflux activity.

    Science.gov (United States)

    Ballent, M; Wilkens, M R; Maté, L; Muscher, A S; Virkel, G; Sallovitz, J; Schröder, B; Lanusse, C; Lifschitz, A

    2013-12-01

    The role of the transporter P-glycoprotein (P-gp) in the disposition kinetics of different drugs therapeutically used in veterinary medicine has been demonstrated. Considering the anatomo-physiological features of the ruminant species, the constitutive expression of P-gp (ABCB1) along the sheep gastrointestinal tract was studied. Additionally, the effect of repeated dexamethasone (DEX) administrations on the ABCB1 gene expression in the liver and small intestine was also assessed. The ABCB1 mRNA expression was determined by real-time quantitative PCR. P-gp activity was evaluated in diffusion chambers to determine the efflux of rhodamine 123 (Rho 123) in the ileum from experimental sheep. The constitutive ABCB1 expression was 65-fold higher in the liver than in the intestine (ileum). The highest ABCB1 mRNA expression along the small intestine was observed in the ileum (between 6- and 120-fold higher). The treatment with DEX did not elicit a significant effect on the P-gp gene expression levels in any of the investigated gastrointestinal tissues. Consistently, no significant differences were observed in the intestinal secretion of Rho 123, between untreated control (Peff S-M = 3.99 × 10(-6)  ± 2.07 × 10(-6) ) and DEX-treated animals (Peff S-M = 6.00 × 10(-6)  ± 2.5 × 10(-6) ). The understanding of the efflux transporters expression and activity along the digestive tract may help to elucidate clinical implications emerging from drug interactions in livestock.

  10. Survey of Genes Involved in Biosynthesis, Transport, and Signaling of Phytohormones with Focus on Solanum lycopersicum

    Science.gov (United States)

    Simm, Stefan; Scharf, Klaus-Dieter; Jegadeesan, Sridharan; Chiusano, Maria Luisa; Firon, Nurit; Schleiff, Enrico

    2016-01-01

    Phytohormones control the development and growth of plants, as well as their response to biotic and abiotic stress. The seven most well-studied phytohormone classes defined today are as follows: auxins, ethylene, cytokinin, abscisic acid, jasmonic acid, gibberellins, and brassinosteroids. The basic principle of hormone regulation is conserved in all plants, but recent results suggest adaptations of synthesis, transport, or signaling pathways to the architecture and growth environment of different plant species. Thus, we aimed to define the extent to which information from the model plant Arabidopsis thaliana is transferable to other plants such as Solanum lycopersicum. We extracted the co-orthologues of genes coding for major pathway enzymes in A. thaliana from the translated genomes of 12 species from the clade Viridiplantae. Based on predicted domain architecture and localization of the identified proteins from all 13 species, we inspected the conservation of phytohormone pathways. The comparison was complemented by expression analysis of (co-) orthologous genes in S. lycopersicum. Altogether, this information allowed the assignment of putative functional equivalents between A. thaliana and S. lycopersicum but also pointed to some variations between the pathways in eudicots, monocots, mosses, and green algae. These results provide first insights into the conservation of the various phytohormone pathways between the model system A. thaliana and crop plants such as tomato. We conclude that orthologue prediction in combination with analysis of functional domain architecture and intracellular localization and expression studies are sufficient tools to transfer information from model plants to other plant species. Our results support the notion that hormone synthesis, transport, and response for most part of the pathways are conserved, and species-specific variations can be found. PMID:27695302

  11. Chromosomal localization of the murine RFC-1 gene encoding a folate transporter and its amplification in an antifolate resistant variant overproducing the transporter.

    Science.gov (United States)

    Roy, K; Chiao, J H; Spengler, B A; Tolner, B; Yang, C H; Biedler, J L; Sirotnak, F M

    1998-08-01

    A variant of the L1210 cell (L1210/R83) selected in the presence of the lipophilic antifolate, metoprine, and a concentration of the natural diastereoisomer of 5-formyltetrahydrofolate, lL5CHO-folateH4, suboptimum for growth exhibited a 35-fold increase compared to parental L1210 cells in one-carbon, reduced folate transport. This was evidenced by the increase in Vmax for [3H]MTX (methotrexate) influx and a commensurate increase in the amount of the 46 kilodalton (kDa) transport protein and reduced folate carrier (RFC-1) mRNA. The variant is resistant to lipophilic antifolates, but shows collateral sensitivity to classical folate analogues. Karyotype analysis of L1210/R83 cells revealed the presence of several new chromosome abnormalities. One of these was a large, submetacentric marker chromosome comprising a normal #10 and a longer, abnormally banded arm of uncertain origin which exhibited an interstitial, palely staining, HSR-like segment. The results of Southern and Northern blotting showed that the RFC-1 gene copy number and RNA transcript level were markedly increased (30-35 fold) in L1210/R83 cells. Fluorescence in situ hybridization (FISH) analysis revealed that the HSR-like segment in these cells was the site of amplified RFC-1 genes. Independent revertant subclones, obtained following growth in the absence of selection pressure, showed four- to 12-fold decreases in [3H]MTX influx Vmax and in amount of NHS (N-hydroxysuccinimide)-[3H]MTX affinity labeled one-carbon, reduced folate transporter compared to L1210/R83 cells. RFC-1 gene copy number also decreased, and the mean length of the HSR in these revertants declined 1.6- to 5-fold. Based upon genomic nucleotide sequencing, the RFC-1 gene in the normal mouse genome was localized to chromosome 10 in close association with the alpha 1 (Col18a1) collagen gene at 10B3(locus 41cM). The close association of these genes was confirmed by other data showing that the alpha 1 collagen gene was co-amplified in L1210/R

  12. A single molecule detection method for understanding mechanisms of electric field-mediated interstitial transport of genes.

    Science.gov (United States)

    Henshaw, Joshua W; Zaharoff, David A; Mossop, Brian J; Yuan, Fan

    2006-10-01

    The interstitial space is a rate limiting physiological barrier to non-viral gene delivery. External pulsed electric fields have been proposed to increase DNA transport in the interstitium, thereby improving non-viral gene delivery. In order to characterize and improve the interstitial transport, we developed a reproducible single molecule detection method to observe the electromobility of DNA in a range of pulsed, high field strength electric fields typically used during electric field-mediated gene delivery. Using agarose gel as an interstitium phantom, we investigated the dependence of DNA electromobility on field magnitude, pulse duration, pulse interval, and pore size in the interstitial space. We observed that the characteristic electromobility behavior, exhibited under most pulsing conditions, consisted of three distinct phases: stretching, reptation, and relaxation. Electromobility depended strongly on the field magnitude, pulse duration, and pulse interval of the applied pulse sequences, as well as the pore size of the fibrous matrix through which the DNA migrated. Our data also suggest the existence of a minimum pulse amplitude required to initiate electrophoretic transport. These results are useful for understanding the mechanisms of DNA electromobility and improving interstitial transport of genes during electric field-mediated gene delivery.

  13. Involvement of CjMDR1, a plant multidrug-resistance-type ATP-binding cassette protein, in alkaloid transport in Coptis japonica

    Science.gov (United States)

    Shitan, Nobukazu; Bazin, Ingrid; Dan, Kazuyuki; Obata, Kazuaki; Kigawa, Koji; Ueda, Kazumitsu; Sato, Fumihiko; Forestier, Cyrille; Yazaki, Kazufumi

    2003-01-01

    Alkaloids comprise one of the largest groups of plant secondary metabolites. Berberine, a benzylisoquinoline alkaloid, is preferentially accumulated in the rhizome of Coptis japonica, a ranunculaceous plant, whereas gene expression for berberine biosynthetic enzymes has been observed specifically in root tissues, which suggests that berberine synthesized in the root is transported to the rhizome, where there is high accumulation. We recently isolated a cDNA encoding a multidrug-resistance protein (MDR)-type ATP-binding cassette (ABC) transporter (Cjmdr1) from berberine-producing cultured C. japonica cells, which is highly expressed in the rhizome. Functional analysis of Cjmdr1 by using a Xenopus oocyte expression system showed that CjMDR1 transported berberine in an inward direction, resulting in a higher accumulation of berberine in Cjmdr1-injected oocytes than in the control. Typical inhibitors of ABC proteins, such as vanadate, nifedipine, and glibenclamide, as well as ATP depletion, clearly inhibited this CjMDR1-dependent berberine uptake, suggesting that CjMDR1 functioned as an ABC transporter. Conventional membrane separation methods showed that CjMDR1 was localized in the plasma membrane of C. japonica cells. In situ hybridization indicated that Cjmdr1 mRNA was expressed preferentially in xylem tissues of the rhizome. These findings strongly suggest that CjMDR1 is involved in the translocation of berberine from the root to the rhizome. PMID:12524452

  14. Quantitative gene expression of somatostatin receptors and noradrenaline transporter underlying scintigraphic results in patients with neuroendocrine tumors

    DEFF Research Database (Denmark)

    Binderup, Tina; Knigge, Ulrich; Mellon Mogensen, Anne;

    2008-01-01

    AIM: To measure, by a quantitative approach, the gene expression underlying the results of somatostatin receptor (sst) scintigraphy ((111)In-DTPA-octreotide) and noradrenaline transporter (NAT) scintigraphy ((123)I-MIBG) in patients with neuroendocrine (NE) tumors. METHODS: The gene expression...... MIBG scintigraphies). RESULTS: The sst(2) was upregulated in 13 of 14 patients (93%) with NE tumors, and the absolute level of gene expression was highest for sst(2). Gene expression alterations of NAT and the other sst subtypes were more variable. Gene expression of sst(2) was in all cases...... in agreement with positive octreotide scintigraphies. In 2 of 3 cases where MIBG scintigraphy was positive, NAT was also upregulated. Sst(2) was generally downregulated in the colorectal tumor group with the gene expression of the other receptors being more heterogeneous. CONCLUSIONS: In general, changes...

  15. Investigation of the fatty acid transporter-encoding genes SLC27A3 and SLC27A4 in autism

    OpenAIRE

    Motoko Maekawa; Yoshimi Iwayama; Tetsuo Ohnishi; Manabu Toyoshima; Chie Shimamoto; Yasuko Hisano; Tomoko Toyota; Shabeesh Balan; Hideo Matsuzaki; Yasuhide Iwata; Shu Takagai; Kohei Yamada; Motonori Ota; Satoshi Fukuchi; Yohei Okada

    2015-01-01

    The solute carrier 27A (SLC27A) gene family encodes fatty acid transport proteins (FATPs) and includes 6 members. During fetal and postnatal periods of development, the growing brain requires a reliable supply of fatty acids. Because autism spectrum disorders (ASD) are now recognized as disorders caused by impaired early brain development, it is possible that functional abnormalities of SLC27A genes may contribute to the pathogenesis of ASD. Here, we confirmed the expression of SLC27A3 and SL...

  16. Membrane transporters in self resistance of Cercospora nicotianae to the photoactivated toxin cercosporin.

    Science.gov (United States)

    Beseli, Aydin; Amnuaykanjanasin, Alongkorn; Herrero, Sonia; Thomas, Elizabeth; Daub, Margaret E

    2015-11-01

    The goal of this work is to characterize membrane transporter genes in Cercospora fungi required for autoresistance to the photoactivated, active-oxygen-generating toxin cercosporin they produce for infection of host plants. Previous studies implicated a role for diverse membrane transporters in cercosporin resistance. In this study, transporters identified in a subtractive cDNA library between a Cercospora nicotianae wild type and a cercosporin-sensitive mutant were characterized, including two ABC transporters (CnATR2, CnATR3), an MFS transporter (CnMFS2), a uracil transporter, and a zinc transport protein. Phylogenetic analysis showed that only CnATR3 clustered with transporters previously characterized to be involved in cercosporin resistance. Quantitative RT-PCR analysis of gene expression under conditions of cercosporin toxicity, however, showed that only CnATR2 was upregulated, thus this gene was selected for further characterization. Transformation and expression of CnATR2 in the cercosporin-sensitive fungus Neurospora crassa significantly increased cercosporin resistance. Targeted gene disruption of CnATR2 in the wild type C. nicotianae, however, did not decrease resistance. Expression analysis of other transporters in the cnatr2 mutant under conditions of cercosporin toxicity showed significant upregulation of the cercosporin facilitator protein gene (CFP), encoding an MFS transporter previously characterized as playing an important role in cercosporin autoresistance in Cercospora species. We conclude that cercosporin autoresistance in Cercospora is mediated by multiple genes, and that the fungus compensates for mutations by up-regulation of other resistance genes. CnATR2 may be a useful gene, alone or in addition to other known resistance genes, for engineering Cercospora resistance in crop plants.

  17. Association study of promoter polymorphisms at the dopamine transporter gene in Attention Deficit Hyperactivity Disorder

    Directory of Open Access Journals (Sweden)

    Huang Yu-Shu

    2009-02-01

    Full Text Available Abstract Background Attention deficit hyperactivity disorder (ADHD is a complex neurobehavioral disorder. The dopamine transporter gene (DAT1/SLC6A3 has been considered a good candidate for ADHD. Most association studies with ADHD have investigated the 40-base-pair variable number of tandem repeat (VNTR polymorphism in the 3'-untranslated region of DAT1. Only few studies have reported association between promoter polymorphisms of the gene and ADHD. Methods To investigate the association between the polymorphisms -67A/T (rs2975226 and -839C/T (rs2652511 in promoter region of DAT1 in ADHD, two samples of ADHD patients from the UK (n = 197 and Taiwan (n = 212 were genotyped, and analysed using within-family transmission disequilibrium test (TDT. Results A significant association was found between the T allele of promoter polymorphism -67A/T and ADHD in the Taiwanese population (P = 0.001. There was also evidence of preferential transmission of the T allele of -67A/T polymorphism in combined samples from the UK and Taiwan (P = 0.003. No association was detected between the -839C/T polymorphism and ADHD in either of the two populations. Conclusion The finding suggests that genetic variation in the promoter region of DAT1 may be a risk factor in the development of ADHD.

  18. Predicting childhood effortful control from interactions between early parenting quality and children's dopamine transporter gene haplotypes.

    Science.gov (United States)

    Li, Yi; Sulik, Michael J; Eisenberg, Nancy; Spinrad, Tracy L; Lemery-Chalfant, Kathryn; Stover, Daryn A; Verrelli, Brian C

    2016-02-01

    Children's observed effortful control (EC) at 30, 42, and 54 months (n = 145) was predicted from the interaction between mothers' observed parenting with their 30-month-olds and three variants of the solute carrier family C6, member 3 (SLC6A3) dopamine transporter gene (single nucleotide polymorphisms in intron8 and intron13, and a 40 base pair variable number tandem repeat [VNTR] in the 3'-untranslated region [UTR]), as well as haplotypes of these variants. Significant moderating effects were found. Children without the intron8-A/intron13-G, intron8-A/3'-UTR VNTR-10, or intron13-G/3'-UTR VNTR-10 haplotypes (i.e., haplotypes associated with the reduced SLC6A3 gene expression and thus lower dopamine functioning) appeared to demonstrate altered levels of EC as a function of maternal parenting quality, whereas children with these haplotypes demonstrated a similar EC level regardless of the parenting quality. Children with these haplotypes demonstrated a trade-off, such that they showed higher EC, relative to their counterparts without these haplotypes, when exposed to less supportive maternal parenting. The findings revealed a diathesis-stress pattern and suggested that different SLC6A3 haplotypes, but not single variants, might represent different levels of young children's sensitivity/responsivity to early parenting.

  19. Tungsten transport protein A (WtpA) in Pyrococcus furiosus: the first member of a new class of tungstate and molybdate transporters.

    Science.gov (United States)

    Bevers, Loes E; Hagedoorn, Peter-Leon; Krijger, Gerard C; Hagen, Wilfred R

    2006-09-01

    A novel tungstate and molybdate binding protein has been discovered from the hyperthermophilic archaeon Pyrococcus furiosus. This tungstate transport protein A (WtpA) is part of a new ABC transporter system selective for tungstate and molybdate. WtpA has very low sequence similarity with the earlier-characterized transport proteins ModA for molybdate and TupA for tungstate. Its structural gene is present in the genome of numerous archaea and some bacteria. The identification of this new tungstate and molybdate binding protein clarifies the mechanism of tungstate and molybdate transport in organisms that lack the known uptake systems associated with the ModA and TupA proteins, like many archaea. The periplasmic protein of this ABC transporter, WtpA (PF0080), was cloned and expressed in Escherichia coli. Using isothermal titration calorimetry, WtpA was observed to bind tungstate (dissociation constant [K(D)] of 17 +/- 7 pM) and molybdate (K(D) of 11 +/- 5 nM) with a stoichiometry of 1.0 mol oxoanion per mole of protein. These low K(D) values indicate that WtpA has a higher affinity for tungstate than do ModA and TupA and an affinity for molybdate similar to that of ModA. A displacement titration of molybdate-saturated WtpA with tungstate showed that the tungstate effectively replaced the molybdate in the binding site of the protein.

  20. Expression of the Genes Encoding the Trk and Kdp Potassium Transport Systems of Mycobacterium tuberculosis during Growth In Vitro

    Directory of Open Access Journals (Sweden)

    Moloko C. Cholo

    2015-01-01

    Full Text Available Two potassium (K+-uptake systems, Trk and Kdp, are operative in Mycobacterium tuberculosis (Mtb, but the environmental factors triggering their expression have not been determined. The current study has evaluated the expression of these genes in the Mtb wild-type and a trk-gene knockout strain at various stages of logarithmic growth in relation to extracellular K+ concentrations and pH. In both strains, mRNA levels of the K+-uptake encoding genes were relatively low compared to those of the housekeeping gene, sigA, at the early- and mid-log phases, increasing during late-log. Increased gene expression coincided with decreased K+ uptake in the context of a drop in extracellular pH and sustained high extracellular K+ concentrations. In an additional series of experiments, the pH of the growth medium was manipulated by the addition of 1N HCl/NaOH. Decreasing the pH resulted in reductions in both membrane potential and K+ uptake in the setting of significant induction of genes encoding both K+ transporters. These observations are consistent with induction of the genes encoding the active K+ transporters of Mtb as a strategy to compensate for loss of membrane potential-driven uptake of K+ at low extracellular pH. Induction of these genes may promote survival in the acidic environments of the intracellular vacuole and granuloma.

  1. The Novel Neuronal Ceroid Lipofuscinosis Gene MFSD8 Encodes a Putative Lysosomal Transporter

    Science.gov (United States)

    Siintola, Eija ; Topcu, Meral ; Aula, Nina ; Lohi, Hannes ; Minassian, Berge A. ; Paterson, Andrew D. ; Liu, Xiao-Qing ; Wilson, Callum ; Lahtinen, Ulla ; Anttonen, Anna-Kaisa ; Lehesjoki, Anna-Elina 

    2007-01-01

    The late-infantile–onset forms are the most genetically heterogeneous group among the autosomal recessively inherited neurodegenerative disorders, the neuronal ceroid lipofuscinoses (NCLs). The Turkish variant was initially considered to be a distinct genetic entity, with clinical presentation similar to that of other forms of late-infantile–onset NCL (LINCL), including age at onset from 2 to 7 years, epileptic seizures, psychomotor deterioration, myoclonus, loss of vision, and premature death. However, Turkish variant LINCL was recently found to be genetically heterogeneous, because mutations in two genes, CLN6 and CLN8, were identified to underlie the disease phenotype in a subset of patients. After a genomewide scan with single-nucleotide–polymorphism markers and homozygosity mapping in nine Turkish families and one Indian family, not linked to any of the known NCL loci, we mapped a novel variant LINCL locus to chromosome 4q28.1-q28.2 in five families. We identified six different mutations in the MFSD8 gene (previously denoted “MGC33302”), which encodes a novel polytopic 518–amino acid membrane protein that belongs to the major facilitator superfamily of transporter proteins. MFSD8 is expressed ubiquitously, with several alternatively spliced variants. Like the majority of the previously identified NCL proteins, MFSD8 localizes mainly to the lysosomal compartment. However, the function of MFSD8 remains to be elucidated. Analysis of the genome-scan data suggests the existence of at least three more genes in the remaining five families, further corroborating the great genetic heterogeneity of LINCLs. PMID:17564970

  2. Searching for the fastest dynamo: laminar ABC flows.

    Science.gov (United States)

    Alexakis, Alexandros

    2011-08-01

    The growth rate of the dynamo instability as a function of the magnetic Reynolds number R(M) is investigated by means of numerical simulations for the family of the Arnold-Beltrami-Childress (ABC) flows and for two different forcing scales. For the ABC flows that are driven at the largest available length scale, it is found that, as the magnetic Reynolds number is increased: (a) The flow that results first in a dynamo is the 2 1/2-dimensional flow for which A=B and C=0 (and all permutations). (b) The second type of flow that results in a dynamo is the one for which A=B≃2C/5 (and permutations). (c) The most symmetric flow, A=B=C, is the third type of flow that results in a dynamo. (d) As R(M) is increased, the A=B=C flow stops being a dynamo and transitions from a local maximum to a third-order saddle point. (e) At larger R(M), the A=B=C flow reestablishes itself as a dynamo but remains a saddle point. (f) At the largest examined R(M), the growth rate of the 2 1/2-dimensional flows starts to decay, the A=B=C flow comes close to a local maximum again, and the flow A=B≃2C/5 (and permutations) results in the fastest dynamo with growth rate γ≃0.12 at the largest examined R(M). For the ABC flows that are driven at the second largest available length scale, it is found that (a) the 2 1/2-dimensional flows A=B,C=0 (and permutations) are again the first flows that result in a dynamo with a decreased onset. (b) The most symmetric flow, A=B=C, is the second type of flow that results in a dynamo. It is, and it remains, a local maximum. (c) At larger R(M), the flow A=B≃2C/5 (and permutations) appears as the third type of flow that results in a dynamo. As R(M) is increased, it becomes the flow with the largest growth rate. The growth rates appear to have some correlation with the Lyapunov exponents, but constructive refolding of the field lines appears equally important in determining the fastest dynamo flow.

  3. The membrane QmoABC complex interacts directly with the dissimilatory adenosine 5´-phosphosulfate reductase in sulfate reducing bacteria

    Directory of Open Access Journals (Sweden)

    Ana Raquel Ramos

    2012-04-01

    Full Text Available The adenosine 5’-phosphosulfate reductase (AprAB is the enzyme responsible for the reduction of adenosine 5’-phosphosulfate (APS to sulfite in the biological process of dissimilatory sulfate reduction, which is carried out by a ubiquitous group of sulfate reducing prokaryotes. The electron donor for AprAB has not been clearly identified, but was proposed to be the QmoABC membrane complex, since an aprBA-qmoABC gene cluster is found in many sulfate-reducing and sulfur-oxidising bacteria. The QmoABC complex is essential for sulfate reduction, but electron transfer between QmoABC and AprAB has not been reported. In this work we provide the first direct evidence that QmoABC and AprAB interact in Desulfovibrio spp., using co-immunoprecipitation, cross-linking Far-Western blot, tag-affinity purification and surface plasmon resonance studies. This showed that the QmoABC-AprAB complex has a strong steady-state affinity (KD = 90 ± 3 nM, but has a transient character due to a fast dissociation rate. Far-Western blot identified QmoA as the Qmo subunit most involved in the interaction. Nevertheless, electron transfer from menaquinol analogues to APS through anaerobically purified QmoABC and AprAB could not be detected. We propose that this reaction requires the involvement of a third partner to allow electron flow driven by a reverse electron bifurcation process i.e. electron confurcation. This process is deemed essential to allow coupling of APS reduction to chemiosmotic energy conservation.

  4. Association between 5-hydroxytryptamine transporter gene-linked polymorphic region and smoking behavior in Chinese males

    Institute of Scientific and Technical Information of China (English)

    CHU Shui-lian; XIAO Dan; WANG Chen; JING Hang

    2009-01-01

    Background Tobacco use is the major risk factor for numerous health problems. However, only 5% of smokers can successfully quit without therapy owing to the highly addictive properties of nicotine. The serotoninergic system may be involved in smoking behavior because nicotine increases brain serotonin secretion, nicotine withdrawal decreases serotonin levels, and a selective serotonin reuptake inhibitor antagonizes the response to nicotine withdrawal. Serotonin transporter (5-HTT) is the most important protein, as it adjusts the serotonin concentration in the synaptic cleft. There is a polymorphism in the upstream regulatory region of the 5-HTT gene, named 5-hydroxytryptamine transporter gene-Iinked poyymorphic region (5-HTTLPR). Compared with the L allele, the S allele of the polymorphism is associated with decreased transcription efficiency of the 5-HTT gene. In this study, we investigated the relationship between this gene polymorphism and smoking behavior in Chinese males.Methods Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was performed to find 5-HTTLPR gene polymorphisms in 144 smokers and 135 age-matched healthy non-smokers. A questionnaire was completed in all recruited subjects.Results The proportion of L/L (15.3% vs 5.2%) and S/L (50.0% vs 33.3%) genotypes was significantly higher in the smokers than that in the non-smokers (χ2=21.9; P <0.01). The odds ratio (OR) adjusted by age, education, effects of family members and friends who smoke, and alcohol intake was 2.9 (95%CI 1.78-4.80). In smokers, the number of cigarettes/day (L/L vs S/L vs S/S: 28+12 vs 20±8 vs 16±6, χ2=18.5, P <0.01), smoking index (L/L vs S/L vs S/S.. 561±446vs 393±341 vs 237+901, χ2=12.5, P <0.01) and score on the Fagerstrom test for nicotine dependence (FTND) (L/L vs S/L vs S/S. 7.8±1.6 vs 6.2±9.5 vs 3.5±9.1, χ2=48.3, P <0.01) were significantly higher in smokers with an L/L or S/L genotype than that in the smokers with the S/S genotype

  5. Chronic and Acute Stress, Gender, and Serotonin Transporter Gene-Environment Interactions Predicting Depression Symptoms in Youth

    Science.gov (United States)

    Hammen, Constance; Brennan, Patricia A.; Keenan-Miller, Danielle; Hazel, Nicholas A.; Najman, Jake M.

    2010-01-01

    Background: Many recent studies of serotonin transporter gene by environment effects predicting depression have used stress assessments with undefined or poor psychometric methods, possibly contributing to wide variation in findings. The present study attempted to distinguish between effects of acute and chronic stress to predict depressive…

  6. Relational Security Moderates the Effect of Serotonin Transporter Gene Polymorphism (5-HTTLPR) on Stress Generation and Depression among Adolescents

    Science.gov (United States)

    Starr, Lisa R.; Hammen, Constance; Brennan, Patricia A.; Najman, Jake M.

    2013-01-01

    Previous research demonstrates that carriers of the short allele of the serotonin transporter gene (5-HTTLPR) show both greater susceptibility to depression in response to stressful life events and higher rates of generation of stressful events in response to depression. The current study examines relational security (i.e., self-reported beliefs…

  7. Interactions between Serotonin Transporter Gene Haplotypes and Quality of Mothers' Parenting Predict the Development of Children's Noncompliance

    Science.gov (United States)

    Sulik, Michael J.; Eisenberg, Nancy; Lemery-Chalfant, Kathryn; Spinrad, Tracy L.; Silva, Kassondra M.; Eggum, Natalie D.; Betkowski, Jennifer A.; Kupfer, Anne; Smith, Cynthia L.; Gaertner, Bridget; Stover, Daryn A.; Verrelli, Brian C.

    2012-01-01

    The LPR and STin2 polymorphisms of the serotonin transporter gene (SLC6A4) were combined into haplotypes that, together with quality of maternal parenting, were used to predict initial levels and linear change in children's (N = 138) noncompliance and aggression from age 18-54 months. Quality of mothers' parenting behavior was observed when…

  8. Gene expression of transporters and phase I/II metabolic enzymes in murine small intestine during fasting

    Directory of Open Access Journals (Sweden)

    van der Meijde Jolanda

    2007-08-01

    Full Text Available Abstract Background Fasting has dramatic effects on small intestinal transport function. However, little is known on expression of intestinal transport and phase I/II metabolism genes during fasting and the role the fatty acid-activated transcription factor PPARα may play herein. We therefore investigated the effects of fasting on expression of these genes using Affymetrix GeneChip MOE430A arrays and quantitative RT-PCR. Results After 24 hours of fasting, expression levels of 33 of the 253 analyzed transporter and phase I/II metabolism genes were changed. Upregulated genes were involved in transport of energy-yielding molecules in processes such as glycogenolysis (G6pt1 and mitochondrial and peroxisomal oxidation of fatty acids (Cact, Mrs3/4, Fatp2, Cyp4a10, Cyp4b1. Other induced genes were responsible for the inactivation of the neurotransmitter serotonin (Sert, Sult1d1, Dtd, Papst2, formation of eicosanoids (Cyp2j6, Cyp4a10, Cyp4b1, or for secretion of cholesterol (Abca1 and Abcg8. Cyp3a11, typically known because of its drug metabolizing capacity, was also increased. Fasting had no pronounced effect on expression of phase II metabolic enzymes, except for glutathione S-transferases which were down-regulated. Time course studies revealed that some genes were acutely regulated, whereas expression of other genes was only affected after prolonged fasting. Finally, we identified 8 genes that were PPARα-dependently upregulated upon fasting. Conclusion We have characterized the response to fasting on expression of transporters and phase I/II metabolic enzymes in murine small intestine. Differentially expressed genes are involved in a variety of processes, which functionally can be summarized as a increased oxidation of fat and xenobiotics, b increased cholesterol secretion, c increased susceptibility to electrophilic stressors, and d reduced intestinal motility. This knowledge increases our understanding of gut physiology, and may be of relevance

  9. Covariance structure of neuroticism and agreeableness: a twin and molecular genetic analysis of the role of the serotonin transporter gene.

    Science.gov (United States)

    Jang, K L; Hu, S; Livesley, W J; Angleitner, A; Riemann, R; Ando, J; Ono, Y; Vernon, P A; Hamer, D H

    2001-08-01

    The Revised NEO Personality Inventory domains of Neuroticism and Agreeableness are considered factorially distinct despite several intercorrelations between these domains. The genetic correlation, an index of the degree to which these intercorrelations are caused by genetic influences, was estimated using data from 913 monozygotic and 562 dizygotic volunteer twin pairs from Canada, Germany, and Japan. The serotonin transporter gene, 5-HTTLPR, was assayed in a sample of 388 nontwin sibling pairs from the United States to determine the contribution of the serotonin transporter locus to the covariation between the Neuroticism and Agreeableness scales. In all four samples, genetic influences contributed to the covariance of Neuroticism and Agreeableness, with the serotonin transporter gene accounting for 10% of the relationship between these domains.

  10. 基于ABC-PCNN模型的图像分割%Image segmentation based on ABC-PCNN model

    Institute of Scientific and Technical Information of China (English)

    廖传柱; 张旦; 江铭炎

    2014-01-01

    为使标准脉冲耦合神经网络( Pulse coupled neural network,PCNN)模型在图像分割中能够自适应地调整模型参数与全局阈值,提高分割效果,该文提出一种基于人工蜂群( Artificial bee colony,ABC)算法改进的自适应PCNN 模型,即人工蜂群算法-脉冲耦合神经网络( ABC-PCNN)模型;提出了改进后的乘积型交叉熵函数,并利用ABC算法将此函数作为其适应度函数优化输出其连接系数和阈值。采用Lena图像和血细胞图像评估PCNN模型和ABC-PCNN模型的性能。实验结果表明:ABC-PCNN模型对图像的自适应分割效果优于PCNN模型。针对血细胞分割图像中存在的重叠区域,该文结合角点和质点坐标定位重叠区域的二次分割线得到最终分割图像,所提算法高效且能得到较好的分割结果。%In order to adjust the model parameters and the global threshold for image segmentation, an improved pulse coupled neural network ( PCNN ) model based on artificial bee colony ( ABC ) algorithm,namely ABC-PCNN,is proposed here. It combines a new criterion of product cross entropy with the standard simplified PCNN model. The product cross entropy is used as the fitness function to optimize the connection output coefficient and threshold value by the ABC algorithm. Lena image and blood cell image are used to evaluate the PCNN model and the ABC-PCNN model respectively. The experimental results show that the adaptive image segmentation by the ABC-PCNN model outperforms that by the PCNN model. As the overlapping areas need secondary segmentation in the segmented blood cell image,corners and center coordinates are used to locate the dividing line and to get the final image segmentation. The method proposed here is effective and can obtain better segmentation results.

  11. Observation of the ABC effect and final-state isospin

    Science.gov (United States)

    Doroshkevich, E. A.; Bashkanov, M. A.; Clement, H.; Perez del Rio, E.; Pricking, A.; Skorodko, T. Yu.; Wagner, G. J.

    2014-07-01

    Despite the number of inclusive measurements of the pionic fusion reactions, the nature of the ABC effect discovered in 1960 was not completely established. Exclusive measurements of the doublepion-production reactions leading to either fused d, 3He and 4He nuclear final states or pp pairs are analyzed. A significant ABC effect—enhancement in the region of low ππ mass—is found only in the isoscalar ππ channel while in the isovector channels it is small or absent. For the reaction with isovector pp final state an ABC effect was not observed even at the special kinematic conditions to reproduce a quasi-bound two-proton state. The total cross sections for the d and 4He fusion reactions show similar resonance-like energy dependence.

  12. 如何实现ABC/ABM与ERP的集成

    Institute of Scientific and Technical Information of China (English)

    伍冬凤

    2006-01-01

    上世纪70年代之后,高新技术的蓬勃发展和广泛应用,为作业成本计算(Activity-Based Cost,ABC)和作业管理(Activity Based Management,ABM)的出现奠定了基础.本文以成本管理理论为起点,结合分析企业资源计划(Enterprise Resources Planning,ERP)系统基本原理与成本管理功能,据以提出一种将ABC/ABM与ERP集成的策略,并描述了ABC/ABM模块主要数据维护流程图.

  13. Chondroitinase ABC improves recovery of long sciatic nerve defects

    Institute of Scientific and Technical Information of China (English)

    Hailong Yu; Liangbi Xiang; Wenjing Xu; Bin Zhao; Yu Wang; Jiang Peng; Shibi Lu

    2012-01-01

    Sciatic nerves from allogeneic Sprague-Dawley rats were pretreated with chondroitinase ABC and were used to bridge damaged sciatic nerves in Wistar rats. Chondroitin sulfate proteoglycans were removed from the chemically extracted acellular nerves. At 3 months after grafting, the footplate pinch test result was positive in the Wistar rats. Autotomy scores decreased, and increased muscular contraction tension appeared when triceps surae muscles were stimulated. In addition, the recovery rate of wet triceps surae muscle weight increased, and the distal segment of the chondroitinase ABC-treated graft exhibited Schwann cells next to the nerve fibers. These results suggested that chondroitinase ABC pretreatment enhanced repair of long nerve defects via acellular nerve grafting.

  14. Enhancing the aluminium tolerance of barley by expressing the citrate transporter genes SbMATE and FRD3.

    Science.gov (United States)

    Zhou, Gaofeng; Pereira, Jorge F; Delhaize, Emmanuel; Zhou, Meixue; Magalhaes, Jurandir V; Ryan, Peter R

    2014-06-01

    Malate and citrate efflux from root apices is a mechanism of Al(3+) tolerance in many plant species. Citrate efflux is facilitated by members of the MATE (multidrug and toxic compound exudation) family localized to the plasma membrane of root cells. Barley (Hordeum vulgare) is among the most Al(3+)-sensitive cereal species but the small genotypic variation in tolerance that is present is correlated with citrate efflux via a MATE transporter named HvAACT1. This study used a biotechnological approach to increase the Al(3+) tolerance of barley by transforming it with two MATE genes that encode citrate transporters: SbMATE is the major Al(3+)-tolerance gene from sorghum whereas FRD3 is involved with Fe nutrition in Arabidopsis. Independent transgenic and null T3 lines were generated for both transgenes. Lines expressing SbMATE showed Al(3+)-activated citrate efflux from root apices and greater tolerance to Al(3+) toxicity than nulls in hydroponic and short-term soil trials. Transgenic lines expressing FRD3 exhibited similar phenotypes except citrate release from roots occurred constitutively. The Al(3+) tolerance of these lines was compared with previously generated transgenic barley lines overexpressing the endogenous HvAACT1 gene and the TaALMT1 gene from wheat. Barley lines expressing TaALMT1 showed significantly greater Al(3+) tolerance than all lines expressing MATE genes. This study highlights the relative efficacy of different organic anion transport proteins for increasing the Al(3+) tolerance of an important crop species.

  15. Osteopenia and male-specific sudden cardiac death in mice lacking a zinc transporter gene, Znt5.

    Science.gov (United States)

    Inoue, Koichi; Matsuda, Koichi; Itoh, Makoto; Kawaguchi, Hiroshi; Tomoike, Hitonobu; Aoyagi, Teruhiko; Nagai, Ryozo; Hori, Masatsugu; Nakamura, Yusuke; Tanaka, Toshihiro

    2002-07-15

    We isolated a mammalian gene whose expression transiently increased in response to intimal denudation of rabbit aorta. It was identical to a gene encoding a zinc transporter, ZNT5, reported very recently by others. Mice deficient for this gene showed poor growth and a decrease in bone density due to impairment of osteoblast maturation to osteocyte. More than 60% of male null mice died suddenly because of the bradyarrhythmias. Analysis of gene-expression profiles in murine hearts by means of an oligonucleotide microarray disclosed that a subset of genes encoding immediate-early response factors (IEGs) and heat shock proteins (HSPs) were down-regulated in Znt5-null mice. These results indicate that Znt5 protein plays an important role in maturation of osteoblasts and in maintenance of the cells involved in the cardiac conduction system, partly owing to dysregulated expression of IEGs and HSPs.

  16. Possible association of the 5-HTTLPR serotonin transporter promoter gene polymorphism with premature ejaculation in a Turkish population

    Institute of Scientific and Technical Information of China (English)

    Emin Ozbek; Ali I.Tasci; Volkan Tugcu; Yusuf O.Ilbey; Abdulmuttalip Simsek; Levent Ozcan; Emre C.Polat; Vedat Koksal

    2009-01-01

    We evaluated the genotypes of the serotonin transporter gene (5-HTT) in patients with premature ejaculation (PE) to determine the role of genetic factors in the etiopathogenesis of PE and possibly to identify the patient subgroups. A total of 70 PE patients and 70 controls were included in this study. All men were heterosexual, had no other disorders and were either married or in a stable relationship. PE was defined as ejaculation that occurred within 1 min of vaginal intromission. Genomic DNA from patients and controls was analyzed using polymerase chain reaction, and allelic variations of the promoter region of the serotonin transporter gene (5-HTTLPR) were determined. The 5-HTTLPR (serotonin transporter promoter gene) genotypes in PE patients vs. Controls were distributed as follows: L/L 16% vs. 17%, L/S 30% vs. 53% and S/S 54% vs. 28%. We examined the haplotype analysis for three polymorphisms of the 5-HTTLPR gene: LL, LS and SS. The appropriateness of the allele frequencies in the 5-HTTLPR gene was analyzed by the Hardy-Weinberg equilibrium using the χ2-test. The short (S) allele of the 5-HTTLPR gene was significantly more frequent in PE patients than in controls (P<0.05). We suggest that the 5-HTTLPR gene plays a role in the pathophysiology of all primary PE cases. Further studies are needed to evaluate the relationship between 5-HTTLPR gene polymorphism and patient subgroup (such as primary and secondary PE) responses to selective serotonin reuptake inhibitors as well as ethnic differences.

  17. Identification and Analysis of Medicago truncatula Auxin Transporter Gene Families Uncover their Roles in Responses to Sinorhizobium meliloti Infection.

    Science.gov (United States)

    Shen, Chenjia; Yue, Runqing; Bai, Youhuang; Feng, Rong; Sun, Tao; Wang, Xiaofei; Yang, Yanjun; Tie, Shuanggui; Wang, Huizhong

    2015-10-01

    Auxin transport plays a pivotal role in the interaction between legume species and nitrogen-fixing bacteria to form symbioses. Auxin influx carriers auxin resistant 1/like aux 1 (AUX/LAX), efflux carriers pin-formed (PIN) and efflux/conditional P-glycoprotein (PGP/ABCB) are three major protein families participating in auxin polar transport. We used the latest Medicago truncatula genome sequence to characterize and analyze the M. truncatula LAX (MtLAX), M. truncatula PIN (MtPIN) and M. truncatula ABCB (MtABCB) families. Transient expression experiments indicated that three representative auxin transporters (MtLAX3, MtPIN7 and MtABCB1) showed cell plasma membrane localizations. The expression of most MtLAX, MtPIN and MtABCB genes was up-regulated in the roots and was down-regulated in the shoots by Sinorhizobium meliloti infection in the wild type (WT). However, the expression of these genes was down-regulated in both the roots and shoots of an infection-resistant mutant, dmi3. The different expression patterns between the WT and the mutant roots indicated that auxin relocation may be involved in rhizobial infection responses. Furthermore, IAA contents were significantly up-regulated in the shoots and down-regulated in the roots after Sinorhizobium meliloti infection in the WT. Inoculation of roots with rhizobia may reduce the auxin loading from shoots to roots by inhibiting the expression of most auxin transporter genes. However, the rate of change of gene expression and IAA contents in the dmi3 mutant were obviously lower than in the WT. The identification and expression analysis of auxin transporter genes helps us to understand the roles of auxin in the regulation of nodule formation in M. truncatula.

  18. Effects of lipid environment on the conformational changes of an ABC importer.

    Science.gov (United States)

    Rice, Austin J; Alvarez, Frances J D; Davidson, Amy L; Pinkett, Heather W

    2014-01-01

    In order to shuttle substrates across the lipid bilayer, membrane proteins undergo a series of conformation changes that are influenced by protein structure, ligands, and the lipid environment. To test the effect of lipid on conformation change of the ABC transporter MolBC, EPR studies were conducted in lipids and detergents of variable composition. In both a detergent and lipid environment, MolBC underwent the same general conformation changes as detected by site-directed EPR spectroscopy. However, differences in activity and the details of the EPR analysis indicate conformational rigidity that is dependent on the lipid environment. From these observations, we conclude that native-like lipid mixtures provide the transporter with greater activity and conformational flexibility as well as technical advantages such as reconstitution efficiency and protein stability.

  19. Lotus tenuis tolerates combined salinity and waterlogging: maintaining O2 transport to roots and expression of an NHX1-like gene contribute to regulation of Na+ transport.

    Science.gov (United States)

    Teakle, Natasha L; Amtmann, Anna; Real, Daniel; Colmer, Timothy D

    2010-08-01

    Salinity and waterlogging interact to reduce growth for most crop and pasture species. The combination of these stresses often cause a large increase in the rate of Na(+) and Cl(-) transport to shoots; however, the mechanisms responsible for this are largely unknown. To identify mechanisms contributing to the adverse interaction between salinity and waterlogging, we compared two Lotus species with contrasting tolerances when grown under saline (200 mM NaCl) and O(2)-deficient (stagnant) treatments. Measurements of radial O(2) loss (ROL) under stagnant conditions indicated that more O(2) reaches root tips of Lotus tenuis, compared with Lotus corniculatus. Better internal aeration would contribute to maintaining Na(+) and Cl(-) transport processes in roots of L. tenuis exposed to stagnant-plus-NaCl treatments. L. tenuis root Na(+) concentrations after stagnant-plus-NaCl treatment (200 mM) were 17% higher than L. corniculatus, with 55% of the total plant Na(+) being accumulated in roots, compared with only 39% for L. corniculatus. L. tenuis accumulated more Na(+) in roots, presumably in vacuoles, thereby reducing transport to the shoot (25% lower than L. corniculatus). A candidate gene for vacuole Na(+) accumulation, an NHX1-like gene, was cloned from L. tenuis and identity established via sequencing and yeast complementation. Transcript levels of NHX1 in L. tenuis roots under stagnant-plus-NaCl treatment were the same as for aerated NaCl, whereas L. corniculatus roots had reduced transcript levels. Enhanced O(2) transport to roots enables regulation of Na(+) transport processes in L. tenuis roots, contributing to tolerance to combined salinity and waterlogging stresses.

  20. Organization and sequence of the human P gene and identification of a new family of transport proteins

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.T.; Fukai, K.; Spritz, R.A. [Univ. of Wisconsin School of Medicine, Madison, WI (United States)] [and others

    1995-03-20

    We have determined the structure, nucleotide sequence, and polymorphisms of the human P gene. Mutations of the P gene result in type H oculocutaneous albinism (OCA2) in humans and pink-eyed dilution (p) in mice. We find that the human P gene is quite large, consisting of 25 exons spanning 250 to 600 kb in chromosome segment 15q11-q13. The P polypeptide appears to define a novel family of small molecule transporters and may be involved in transport of tyrosine, the precursor to melanin synthesis, within the melanocyte. These results provide the basis for analyses of patients with OCA2 and may point toward eventual pharmacologic treatment of this and related disorders of pigmentation. 40 refs., 5 figs., 3 tabs.

  1. Association of serotonin transporter gene (5HTT) polymorphism and juvenile myoclonic epilepsy: a case-control study.

    Science.gov (United States)

    Esmail, Eman H; Labib, Dalia M; Rabie, Walaa A

    2015-09-01

    Serotonin levels might alter susceptibility to seizures. Serotonin transporter (5HTT) gene polymorphisms were found to be associated with some forms of epilepsy. Here, we attempted to examine an association between 5HTT VNTR allele variants in a serotonin transporter gene and epileptogenesis in juvenile myoclonic epilepsy (JME) cases. We conducted a case-control candidate gene study evaluating the frequencies of 5HTT VNTR allele variants using SYBR green real-time PCR with melting curve analysis in JME patients and healthy subjects. Forty patients with JME were selected from the Epilepsy Outpatient Clinic of Kasr Al Ainy Hospital, Cairo University, who had been classified according to the electroclinical classification of the ILAE. The control group consisted of 40 healthy Egyptian subjects. The less efficient transcriptional genotypes for 5-HTT polymorphisms were more frequent in JME patients (OR 9.33, CI 2.85-30.60; p value epileptogenesis in JME.

  2. Modification of N-glycosylation sites allows secretion of bacterial chondroitinase ABC from mammalian cells.

    Science.gov (United States)

    Muir, Elizabeth M; Fyfe, Ian; Gardiner, Sonya; Li, Li; Warren, Philippa; Fawcett, James W; Keynes, Roger J; Rogers, John H

    2010-01-15

    Although many eukaryotic proteins have been secreted by transfected bacterial cells, little is known about how a bacterial protein is treated as it passes through the secretory pathway when expressed in a eukaryotic cell. The eukaryotic N-glycosylation system could interfere with folding and secretion of prokaryotic proteins whose sequence has not been adapted for glycosylation in structurally appropriate locations. Here we show that such interference does indeed occur for chondroitinase ABC from the bacterium Proteus vulgaris, and can be overcome by eliminating potential N-glycosylation sites. Chondroitinase ABC was heavily glycosylated when expressed in mammalian cells or in a mammalian translation system, and this process prevented secretion of functional enzyme. Directed mutagenesis of selected N-glycosylation sites allowed efficient secretion of active chondroitinase. As these proteoglycans are known to inhibit regeneration of axons in the mammalian central nervous system, the modified chondroitinase gene is a potential tool for gene therapy to promote neural regeneration, ultimately in human spinal cord injury.

  3. Molecular analysis of the human SLC13A4 sulfate transporter gene promoter

    Energy Technology Data Exchange (ETDEWEB)

    Jefferis, J. [Mater Medical Research Institute, South Brisbane, Queensland (Australia); Rakoczy, J. [Mater Medical Research Institute, South Brisbane, Queensland (Australia); School of Biomedical Sciences, University of Queensland, St. Lucia, Queensland (Australia); Translational Research Institute, Woolloongabba, Queensland (Australia); Simmons, D.G. [School of Biomedical Sciences, University of Queensland, St. Lucia, Queensland (Australia); Dawson, P.A., E-mail: paul.dawson@mmri.mater.org.au [Mater Medical Research Institute, South Brisbane, Queensland (Australia); Translational Research Institute, Woolloongabba, Queensland (Australia)

    2013-03-29

    Highlights: ► Basal promoter activity of SLC13A4 −57 to −192 nt upstream of transcription initiation site. ► Human SLC13A4 5′-flanking region has conserved motifs with other placental species. ► Putative NFY, SP1 and KLF7 motifs in SLC13A4 5′-flanking region enhance transcription. -- Abstract: The human solute linked carrier (SLC) 13A4 gene is primarily expressed in the placenta where it is proposed to mediate the transport of nutrient sulfate from mother to fetus. The molecular mechanisms involved in the regulation of SLC13A4 expression remain unknown. To investigate the regulation of SLC13A4 gene expression, we analysed the transcriptional activity of the human SLC13A4 5′-flanking region in the JEG-3 placental cell line using luciferase reporter assays. Basal transcriptional activity was identified in the region −57 to −192 nucleotides upstream of the SLC13A4 transcription initiation site. Mutational analysis of the minimal promoter region identified Nuclear factor Y (NFY), Specificity protein 1 (SP1) and Krüppel like factor 7 (KLF7) motifs which conferred positive transcriptional activity, as well as Zinc finger protein of the cerebellum 2 (ZIC2) and helix–loop–helix protein 1 (HEN1) motifs that repressed transcription. The conserved NFY, SP1, KLF7, ZIC2 and HEN1 motifs in the SLC13A4 promoter of placental species but not in non-placental species, suggests a potential role for these putative transcriptional factor binding motifs in the physiological control of SLC13A4 mRNA expression.

  4. Arabidopsis SOI33/AtENT8 Gene Encodes a Putative Equilibrative Nucleoside Transporter That Is Involved in Cytokinin Transport In Planta

    Institute of Scientific and Technical Information of China (English)

    Jiaqiang SUN; Naoya HIROSE; Xingchun WANG; Pei WEN; Li XUE; Hitoshi SAKAKIBARA; Jianru ZUO

    2005-01-01

    The plant phytohormone cytokinin plays an important role in many facets of plant growth and development by regulating cell division and differentiation. Recent studies have shed significant light into the mechanisms of cytokinin metabolism and signaling. However, little is known about how the hormone is transported in planta, although it has been proposed that the hormone is presumably transported in nucleoside-conjugated forms. Here, we report the identification and characterization of cytokinin transport ers in Arabidopsis. We previously reported that a gain-of-function mutation in the PGA22/AtIPT8 gene caused overproduction of cytokinins in planta. In an effort to screen for suppressor of pga22/atipt8 (soi) mutants, we identified a mutant soi33-1. Molecular and genetic analyses indicated that SOI33 encodes a putative equilibrative nucleoside transporter (ENT), previously designated as AtENT8. Members of this small gene family are presumed to be involved in the transport of nucleosides in eukaryotic cells. Under conditions of nitrogen starvation, loss-of-function mutations in SOI33/AtENT8 or in a related gene AtENT3 cause a reduced sensitivity to the nucleoside-type cytokinins isopentenyladenine riboside (iPR) and trans zeatin riboside (tZR), but display a normal response to the free base-type cytokinins isopentenyladenine (iP) and trans-zeatin (tZ). Conversely, overexpression of SOI33/AtENT8 renders transgenic plants hyper sensitive to iPR but not to iP. An in planta measurement experiment indicated that uptake efficiency of 3H labeled iPR was reduced more than 40% in soi33 and atent3 mutants. However, a mutation inAtENT1 had no substantial effect on the cytokinin response and iPR uptake efficiency. Our results suggest that SOI33/ AtENT8 and AtENT3 are involved in the transport of nucleoside-type cytokinins in Arabidopsis.

  5. Optimization of the drug management by the ABC-VEN method%ABC-VEN法优化药品管理

    Institute of Scientific and Technical Information of China (English)

    陶萍

    2010-01-01

    目的 优化药品库存,提高药品管理水平,节约药品管理成本.方法 使用ABC-VEN法对药品进行科学分类,根据分类采用不同的库存管理.结果 使用ABC-VEN法对药品实行优化管理,保证了临床药品供应,压缩了药品库存,提高了药品管理效率.结论 运用ABC-VEN法对药品进行优化管理切实可行,为医院药品管理提供了一定的理论和实践参考.

  6. Expression profiles of the genes associated with metabolism and transport of amino acids and their derivatives in rat liver regeneration.

    Science.gov (United States)

    Xu, C S; Chang, C F

    2008-01-01

    Amino acids (AA) are components of protein and precursors of many important biological molecules. To address effects of the genes associated with metabolism and transport of AA and their derivatives during rat liver regeneration (LR), we firstly obtained the above genes by collecting databases data and retrieving related thesis, and then analyzed their expression profiles during LR using Rat Genome 230 2.0 array. The LR-associated genes were identified by comparing the gene expression difference between partial hepatectomy (PH) and sham-operation (SO) rat livers. It was approved that 134 genes associated with metabolism of AA and their derivatives and 26 genes involved in transport of them were LR-associated. The initially and totally expressing number of these genes occurring in initial phase of LR (0.5-4 h after PH), G0/G1 (4-6 h after PH), cell proliferation (6-66 h after PH), cell differentiation and structure-function reconstruction of liver tissue (72-168 h after PH) were respectively 76, 17, 79, 5 and 162, 89, 564, 195, illustrating that these LR-associated genes were initially expressed mainly in initial stage, and functioned in different phases. Frequencies of up-regulation and down-regulation of them being separately 564 and 357 demonstrated that genes up-regulated outnumbered those down-regulated. Categorization of their expression patterns into 22 types implied the diversity of cell physiological and biochemical activities. According to expression changes and patterns of the above-mentioned genes in LR, it was presumed that histidine biosynthesis in the metaphase and anaphase, valine metabolism in the anaphase, and metabolism of glutamate, glutamine, asparate, asparagine, methionine, alanine, leucine and aromatic amino acid almost were enhanced in the whole LR; as for amino acid derivatives, transport of neutral amino acids, urea, gamma-aminobutyric acid, betaine and taurine, metabolism of dopamine, heme, S-adenosylmethionine, thyroxine, and

  7. The expressions of ABCC4 and ABCG2 xenobiotic transporters in human keratinocytes are proliferation-related.

    Science.gov (United States)

    Bebes, Attila; Kis, Kornélia; Nagy, Tünde; Kurunczi, Anita; Polyánka, Hilda; Bata-Csörgo, Zsuzsanna; Kemény, Lajos; Dobozy, Attila; Széll, Márta

    2012-01-01

    Xenobiotic transporters of the ATP-binding cassette (ABC) protein superfamily play important roles in maintaining the biochemical barrier of various tissues, but their precise functions in the skin are not yet known. Screening of the expressions of the known xenobiotic transporter genes in two in vitro keratinocyte differentiation models revealed that the ABCC4 and ABCG2 transporters are highly expressed in proliferating keratinocytes, their expressions decreasing along with differentiation. Abrogation of the ABCC4 and ABCG2 protein functions by siRNA-mediated silencing and chemical inhibition did not affect the proliferation of HaCaT cells. In contrast, disruption of the ABCG2 function had no effect on normal human epidermal keratinocyte proliferation, while the inhibition of ABCC-type transporters by probenecid resulted in a striking decrease in the proliferation of the cells. These results indicate that, besides their possible therapy-modulating effects, xenobiotic transporters may contribute significantly to other keratinocyte functions, such as cell proliferation.

  8. Responses of phosphate transporter gene and alkaline phosphatase in Thalassiosira pseudonana to phosphine.