scholarly journals Transcriptional study of the ABC transporter-encoding genes in response to fungicide treatment and during plant infection in the phytopathogenic fungusBotrytis cinerea

2016 ◽  
Author(s):  
Elise Loisel ◽  
Isabelle R. Goncalves ◽  
Nathalie Poussereau ◽  
Marie-Claire Grosjean-Cournoyer ◽  
François Villalba ◽  
...  
Keyword(s):  
Abc Transporter ◽  
Abc Transporters ◽  
Grey Mould ◽  
Multi Drug Resistance ◽  
Drug Efflux ◽  
Mould Fungus ◽  
Over Expression ◽  
Plant Infection ◽  
Commercially Important ◽  
Encoding Genes

AbstractThe grey mould fungusBotrytis cinereacauses worldwide losses of commercially important fruits, vegetables and ornamentals. Various fungicides, with different modes of action, are effective against this pathogen, but isolates with multiple fungicide-resistance phenotypes (Multi Drug Resistance, MDR) have been observed with increasing frequency. In fungi, ATP binding cassette (ABC) transporters participate in drug efflux and we report here on the parallel transcriptional study of the predicted ABC transporter-encoding genes inB. cinerea.During plant infection, transcription of all of these genes was activated and over-expression was observed for a few of these genes if the plants were treated with a fungicide prior to infection. In the absence of plant, most of the genes were transcriptionally activated in response to two different fungicides. Both common and specific transcriptional signatures were observed.

scholarly journals Karanjin interferes with ABCB1, ABCC1, and ABCG2

2014 ◽  
Vol 17 (1) ◽  
pp. 92 ◽  
Author(s):  
Martin Michaelis ◽  
Florian Rothweiler ◽  
Thomas Nerreter ◽  
Mohsen Sharifi ◽  
Taravat Ghafourian ◽  
...  
Keyword(s):  
Atpase Activity ◽  
Abc Transporter ◽  
Abc Transporters ◽  
Drug Transport ◽  
Multi Drug Resistance ◽  
Drug Efflux ◽  
Potential Drug ◽  
Antibacterial Effects ◽  
Low Concentrations ◽  
Substance Transport

PURPOSE: The prominent ATP-binding cassette (ABC) transporters ABCB1, ABCC1, and ABCG2 are involved in substance transport across physiological barriers and therefore in drug absorption, distribution, and elimination. They also mediate multi-drug resistance in cancer cells. Different flavonoids are known to interfere with different ABC transporters. Here, the effect of the furanoflavonol karanjin, a potential drug with antiglycaemic, gastroprotective, antifungal, and antibacterial effects, was investigated on ABCB1, ABCC1, and ABCG2-mediated drug transport in comparison to the flavonoids apigenin, genistein, and naringenin. METHODS: Cells expressing the relevant transporters (ABCB1: UKF-NB-3ABCB1, UKF-NB-3rVCR10; ABCC1: G62, PC-3rVCR20; ABCG2: UKF-NB-3ABCG2) were used in combination with specific fluorescent and cytotoxic ABC transporter substrates and ABC transporter inhibitors to study ABC transporter function. Moreover, the effects of the investigated flavonoids were determined on the ABC transporter ATPase activities. RESULTS: Karanjin interfered with drug efflux mediated by ABCB1, ABCC1, and ABCG2 and enhanced the ATPase activity of all three transporters. Moreover, karanjin exerted more pronounced effects than the control flavonoids apigenin, genistein, and naringenin on all three transporters. Most notably, karanjin interfered with ABCB1 at low concentrations being about 1µM. CONCLUSIONS: Taken together, these findings should be taken into account during further consideration of karanjin as a potential drug for different therapeutic indications. The effects on ABCB1, ABCC1, and ABCG2 may affect the pharmacokinetics of co-administered drugs. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.METHODS: Cells expressing the relevant transporters (ABCB1: UKF-NB-3ABCB1, UKF-NB-3rVCR10; ABCC1: G62, PC-3rVCR20; ABCG2: UKF-NB-3ABCG2) were used in combination with specific fluorescent and cytotoxic ABC transporter substrates and ABC transporter inhibitors to study ABC transporter function. Moreover, the effects of the investigated flavonoids were determined on the ABC transporter ATPase activities.RESULTS: Karanjin interfered with drug efflux mediated by ABCB1, ABCC1, and ABCG2 and enhanced the ATPase activity of all three transporters. Moreover, karanjin exerted more pronounced effects than the control flavonoids apigenin, genistein, and naringenin on all three transporters. Most notably, karanjin interfered with ABCB1 at low concentrations being about 1µM.CONCLUSIONS: Taken together, these findings should be taken into account during further consideration of karanjin as a potential drug for different therapeutic indications. The effects on ABCB1, ABCC1, and ABCG2 may affect the pharmacokinetics of co-administered drugs.

scholarly journals Structural basis for the mechanism of ABC transporters

2015 ◽  
Vol 43 (5) ◽  
pp. 889-893 ◽  
Author(s):  
Konstantinos Beis
Keyword(s):  
Drug Resistance ◽  
Binding Site ◽  
Abc Transporter ◽  
Abc Transporters ◽  
Eukaryotic Cells ◽  
Structural Basis ◽  
Multi Drug Resistance ◽  
Hydrolysis Of ◽  
Transport Molecules ◽  
Alternating Access

The ATP-binding cassette (ABC) transporters are primary transporters that couple the energy stored in adenosine triphosphate (ATP) to the movement of molecules across the membrane. ABC transporters can be divided into exporters and importers; importers mediate the uptake of essential nutrients into cells and are found predominantly in prokaryotes whereas exporters transport molecules out of cells or into organelles and are found in all organisms. ABC exporters have been linked with multi-drug resistance in both bacterial and eukaryotic cells. ABC transporters are powered by the hydrolysis of ATP and transport their substrate via the alternating access mechanism, whereby the protein alternates between a conformation in which the substrate-binding site is accessible from the outside of the membrane, outward-facing and one in which it is inward-facing. In this mini-review, the structures of different ABC transporter types in different conformations are presented within the context of the alternating access mechanism and how they have shaped our current understanding of the mechanism of ABC transporters.

scholarly journals Contributions of Aspergillus fumigatus ATP-Binding Cassette Transporter Proteins to Drug Resistance and Virulence

2013 ◽  
Vol 12 (12) ◽  
pp. 1619-1628 ◽  
Author(s):  
Sanjoy Paul ◽  
Daniel Diekema ◽  
W. Scott Moye-Rowley
Keyword(s):  
Drug Resistance ◽  
Aspergillus Fumigatus ◽  
Abc Transporter ◽  
Abc Transporters ◽  
Sequence Similarity ◽  
Atp Binding ◽  
Content Type ◽  
Transporter Proteins ◽  
Encoding Genes ◽  
Atp Binding Cassette

ABSTRACTIn yeast cells such as those ofSaccharomyces cerevisiae, expression of ATP-binding cassette (ABC) transporter proteins has been found to be increased and correlates with a concomitant elevation in azole drug resistance. In this study, we investigated the roles of twoAspergillus fumigatusproteins that share high sequence similarity withS. cerevisiaePdr5, an ABC transporter protein that is commonly overproduced in azole-resistant isolates in this yeast. The twoA. fumigatusgenes encoding the ABC transporters sharing the highest sequence similarity toS. cerevisiaePdr5 are calledabcAandabcBhere. We constructed deletion alleles of these two different ABC transporter-encoding genes in three different strains ofA. fumigatus. Loss ofabcBinvariably elicited increased azole susceptibility, whileabcAdisruption alleles had variable phenotypes. Specific antibodies were raised to both AbcA and AbcB proteins. These antisera allowed detection of AbcB in wild-type cells, while AbcA could be visualized only when overproduced from thehspApromoter inA. fumigatus. Overproduction of AbcA also yielded increased azole resistance. Green fluorescent protein fusions were used to provide evidence that both AbcA and AbcB are localized to the plasma membrane inA. fumigatus. Promoter fusions to firefly luciferase suggested that expression of both ABC transporter-encoding genes is inducible by azole challenge. Virulence assays implicated AbcB as a possible factor required for normal pathogenesis. This work provides important new insights into the physiological roles of ABC transporters in this major fungal pathogen.

Regional variations in ABC transporter expression along the mouse intestinal tract

2004 ◽  
Vol 17 (1) ◽  
pp. 11-20 ◽  
Author(s):  
David M. Mutch ◽  
Pascale Anderle ◽  
Muriel Fiaux ◽  
Robert Mansourian ◽  
Karine Vidal ◽  
...  
Keyword(s):  
Gene Expression ◽  
Abc Transporter ◽  
Expression Profile ◽  
Abc Transporters ◽  
Intestinal Tract ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Assessment Model ◽  
Differentially Expressed ◽  
Distal Intestine

The ATP-binding cassette (ABC) family of proteins comprise a group of membrane transporters involved in the transport of a wide variety of compounds, such as xenobiotics, vitamins, lipids, amino acids, and carbohydrates. Determining their regional expression patterns along the intestinal tract will further characterize their transport functions in the gut. The mRNA expression levels of murine ABC transporters in the duodenum, jejunum, ileum, and colon were examined using the Affymetrix MuU74v2 GeneChip set. Eight ABC transporters (Abcb2, Abcb3, Abcb9, Abcc3, Abcc6, Abcd1, Abcg5, and Abcg8) displayed significant differential gene expression along the intestinal tract, as determined by two statistical models (a global error assessment model and a classic ANOVA, both with a P < 0.01). Concordance with semiquantitative real-time PCR was high. Analyzing the promoters of the differentially expressed ABC transporters did not identify common transcriptional motifs between family members or with other genes; however, the expression profile for Abcb9 was highly correlated with fibulin-1, and both genes share a common complex promoter model involving the NFκB, zinc binding protein factor (ZBPF), GC-box factors SP1/GC (SP1F), and early growth response factor (EGRF) transcription binding motifs. The cellular location of another of the differentially expressed ABC transporters, Abcc3, was examined by immunohistochemistry. Staining revealed that the protein is consistently expressed in the basolateral compartment of enterocytes along the anterior-posterior axis of the intestine. Furthermore, the intensity of the staining pattern is concordant with the expression profile. This agrees with previous findings in which the mRNA, protein, and transport function of Abcc3 were increased in the rat distal intestine. These data reveal regional differences in gene expression profiles along the intestinal tract and demonstrate that a complete understanding of intestinal ABC transporter function can only be achieved by examining the physiologically distinct regions of the gut.

scholarly journals Cross Talk between Sphingolipids and Glycerophospholipids in the Establishment of Plasma Membrane Asymmetry

2004 ◽  
Vol 15 (11) ◽  
pp. 4949-4959 ◽  
Author(s):  
Akio Kihara ◽  
Yasuyuki Igarashi
Keyword(s):  
Plasma Membrane ◽  
Cross Talk ◽  
Abc Transporters ◽  
Transcriptional Factor ◽  
Drug Efflux ◽  
Lipid Asymmetry ◽  
Membrane Asymmetry ◽  
P Type ◽  
Yeast Mutants ◽  
Long Chain

Glycerophospholipids and sphingolipids are distributed asymmetrically between the two leaflets of the lipid bilayer. Recent studies revealed that certain P-type ATPases and ATP-binding cassette (ABC) transporters are involved in the inward movement (flip) and outward movement (flop) of glycerophospholipids, respectively. In this study of phytosphingosine (PHS)-resistant yeast mutants, we isolated mutants for PDR5, an ABC transporter involved in drug efflux as well as in the flop of phosphatidylethanolamine. The pdr5 mutants exhibited an increase in the efflux of sphingoid long-chain bases (LCBs). Genetic analysis revealed that the PHS-resistant phenotypes exhibited by the pdr5 mutants were dependent on Rsb1p, a putative LCB-specific transporter/translocase. We found that the expression of Rsb1p was increased in the pdr5 mutants. We also demonstrated that expression of RSB1 is under the control of the transcriptional factor Pdr1p. Expression of Rsb1p also was enhanced in mutants for the genes involved in the flip of glycerophospholipids, including ROS3, DNF1, and DNF2. These results suggest that altered glycerophospholipid asymmetry induces the expression of Rsb1p. Conversely, overexpression of Rsb1p resulted in increased flip and decreased flop of fluorescence-labeled glycerophospholipids. Thus, there seems to be cross talk between sphingolipids and glycerophospholipids in maintaining the functional lipid asymmetry of the plasma membrane.

scholarly journals Filaments and phenotypes: cellular roles and orphan effects associated with mutations in cytoplasmic intermediate filament proteins

F1000Research ◽  
2019 ◽  
Vol 8 ◽  
pp. 1703 ◽  
Author(s):  
Michael W. Klymkowsky
Keyword(s):  
Intermediate Filaments ◽  
Molecular Chaperones ◽  
High Probability ◽  
Essential Role ◽  
Loss Of Function ◽  
Intermediate Filament Proteins ◽  
Over Expression ◽  
Per Se ◽  
Metabolic Stresses ◽  
Encoding Genes

Cytoplasmic intermediate filaments (IFs) surround the nucleus and are often anchored at membrane sites to form effectively transcellular networks. Mutations in IF proteins (IFps) have revealed mechanical roles in epidermis, muscle, liver, and neurons. At the same time, there have been phenotypic surprises, illustrated by the ability to generate viable and fertile mice null for a number of IFp-encoding genes, including vimentin. Yet in humans, the vimentin (VIM) gene displays a high probability of intolerance to loss-of-function mutations, indicating an essential role. A number of subtle and not so subtle IF-associated phenotypes have been identified, often linked to mechanical or metabolic stresses, some of which have been found to be ameliorated by the over-expression of molecular chaperones, suggesting that such phenotypes arise from what might be termed “orphan” effects as opposed to the absence of the IF network per se, an idea originally suggested by Toivola et al. and Pekny and Lane.

scholarly journals Novel Mechanisms of Efflux-Mediated Levofloxacin Resistance and Reduced Amikacin Susceptibility in Stenotrophomonas maltophilia

2020 ◽  
Vol 65 (1) ◽  
pp. e01284-20
Author(s):  
Punyawee Dulyayangkul ◽  
Karina Calvopiña ◽  
Kate J. Heesom ◽  
Matthew B. Avison
Keyword(s):  
Abc Transporter ◽  
Abc Transporters ◽  
Stenotrophomonas Maltophilia ◽  
Efflux Pump ◽  
Regulatory System ◽  
Fluoroquinolone Resistance ◽  
Content Type ◽  
Antimicrobial Drug Resistance ◽  
Regulatory Systems ◽  
Selection Of

ABSTRACTFluoroquinolone resistance in Stenotrophomonas maltophilia is multifactorial, but the most significant factor is overproduction of efflux pumps, particularly SmeDEF, following mutation. Here, we report that mutations in the glycosyl transferase gene smlt0622 in S. maltophilia K279a mutant K M6 cause constitutive activation of SmeDEF production, leading to elevated levofloxacin MIC. Selection of a levofloxacin-resistant K M6 derivative, K M6 LEVr, allowed identification of a novel two-component regulatory system, Smlt2645/6 (renamed SmaRS). The sensor kinase Smlt2646 (SmaS) is activated by mutation in K M6 LEVr causing overproduction of two novel ABC transporters and the known aminoglycoside efflux pump SmeYZ. Overproduction of one ABC transporter, Smlt1651-4 (renamed SmaCDEF), causes levofloxacin resistance in K M6 LEVr. Overproduction of the other ABC transporter, Smlt2642/3 (renamed SmaAB), and SmeYZ both contribute to the elevated amikacin MIC against K M6 LEVr. Accordingly, we have identified two novel ABC transporters associated with antimicrobial drug resistance in S. maltophilia and two novel regulatory systems whose mutation causes resistance to levofloxacin, clinically important as a promising drug for monotherapy against this highly resistant pathogen.

scholarly journals ABC transporters in gills of rainbow trout (Oncorhynchus mykiss)

2020 ◽  
Vol 223 (15) ◽  
pp. jeb221069
Author(s):  
Christian Kropf ◽  
Karl Fent ◽  
Stephan Fischer ◽  
Ayako Casanova ◽  
Helmut Segner
Keyword(s):  
Rainbow Trout ◽  
Abc Transporter ◽  
Abc Transporters ◽  
Functional Activity ◽  
Organic Molecules ◽  
Expression Patterns ◽  
Primary Cultures ◽  
Gene Transcript ◽  
Rainbow Trout Oncorhynchus Mykiss

ABSTRACTFish gills are a structurally and functionally complex organ at the interface between the organism and the aquatic environment. Gill functions include the transfer of organic molecules, both natural ones and xenobiotic compounds. Whether the branchial exchange of organic molecules involves active transporters is currently not known. Here, we investigated the presence, diversity and functional activity of ATP-binding cassette (ABC) transporters in gills of juvenile rainbow trout. By means of RT-qPCR, gene transcripts of members from the abcb, abcc and abcg subfamilies were identified. Comparisons with mRNA profiles from trout liver and kidney revealed that ABC transporters known to have an apical localization in polarized epithelia, especially abcc2 and abcb1, were under-represented in the gills. In contrast, ABC transporters with mainly basolateral localization showed comparable gene transcript levels in the three organs. The most prominent ABC transporter in gills was an abcb subfamily member, which was annotated as abcb5 based on the synteny and phylogeny. Functional in vivo assays pointed to a role of branchial ABC transporters in branchial solute exchange. We further assessed the utility of primary gill cell cultures to characterize transporter-mediated branchial exchange of organic molecules, by examining ABC transporter gene transcript patterns and functional activity in primary cultures. The gill cultures displayed functional transport activity, but the ABC mRNA expression patterns were different to those of the intact gills. Overall, the findings of this study provide evidence for the presence of functional ABC transporter activity in gills of fish.

scholarly journals ATP Binding Cassette Transporter A1 is Involved in Extracellular Secretion of Acetylated APE1/Ref-1

2019 ◽  
Vol 20 (13) ◽  
pp. 3178 ◽  
Author(s):  
Yu Ran Lee ◽  
Hee Kyoung Joo ◽  
Eun Ok Lee ◽  
Hyun Sil Cho ◽  
Sunga Choi ◽  
...  
Keyword(s):  
Abc Transporter ◽  
Abc Transporters ◽  
Secretory Pathway ◽  
Trichostatin A ◽  
Atp Binding ◽  
Terminal Protein ◽  
Secretion Signal ◽  
Extracellular Secretion ◽  
Atp Binding Cassette Transporter ◽  
Atp Binding Cassette

Acetylation of nuclear apurinic/apyrimidinic endonuclease-1/redox factor-1 (APE1/Ref-1) is associated with its extracellular secretion, despite the lack of an N-terminal protein secretion signal. In this study, we investigated plasma membrane targeting and translocation of APE1/Ref-1 in HEK293T cells with enhanced acetylation. While APE1/Ref-1 targeting was not affected by inhibition of the endoplasmic reticulum/Golgi-dependent secretion, its secretion was reduced by inhibitors of ATP-binding cassette (ABC) transporters, and siRNA-mediated down-regulation of ABC transporter A1. The association between APE1/Ref-1 and ABCA1 transporter was confirmed by proximal ligation assay and immunoprecipitation experiments. An APE1/Ref-1 construct with mutated acetylation sites (K6/K7R) showed reduced co-localization with ABC transporter A1. Exposure of trichostatin A (TSA) induced the acetylation of APE1/Ref-1, which translocated into membrane fraction. Taken together, acetylation of APE1/Ref-1 is considered to be necessary for its extracellular targeting via non-classical secretory pathway using the ABCA1 transporter.

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