scholarly journals Genetic Analysis of the Mode of Interplay between an ATPase Subunit and Membrane Subunits of the Lipoprotein-Releasing ATP-Binding Cassette Transporter LolCDE

2006 ◽  
Vol 188 (8) ◽  
pp. 2856-2864 ◽  
Author(s):  
Yasuko Ito ◽  
Hitomi Matsuzawa ◽  
Shin-ichi Matsuyama ◽  
Shin-ichiro Narita ◽  
Hajime Tokuda
Keyword(s):  
Abc Transporters ◽  
Atp Hydrolysis ◽  
Dominant Negative ◽  
Growth Defect ◽  
Atp Binding ◽  
Inner Membrane ◽  
Atpase Subunit ◽  
E Coli ◽  
Atp Binding Cassette Transporter ◽  
Atp Binding Cassette

ABSTRACT The LolCDE complex, an ATP-binding cassette (ABC) transporter, releases lipoproteins from the inner membrane, thereby initiating lipoprotein sorting to the outer membrane of Escherichia coli. The LolCDE complex is composed of two copies of an ATPase subunit, LolD, and one copy each of integral membrane subunits LolC and LolE. LolD hydrolyzes ATP on the cytoplasmic side of the inner membrane, while LolC and/or LolE recognize and release lipoproteins anchored to the periplasmic leaflet of the inner membrane. Thus, functional interaction between LolD and LolC/E is critically important for coupling of ATP hydrolysis to the lipoprotein release reaction. LolD contains a characteristic sequence called the LolD motif, which is highly conserved among LolD homologs but not other ABC transporters of E. coli. The LolD motif is suggested to be a region in contact with LolC/E, judging from the crystal structures of other ABC transporters. To determine the functions of the LolD motif, we mutagenized each of the 32 residues of the LolD motif and isolated 26 dominant-negative mutants, whose overexpression arrested growth despite the chromosomal lolD + background. We then selected suppressor mutations of the lolC and lolE genes that correct the growth defect caused by the LolD mutations. Mutations of the lolC suppressors were mainly located in the periplasmic loop, whereas ones of lolE suppressors were mainly located in the cytoplasmic loop, suggesting that the mode of interaction with LolD differs between LolC and LolE. Moreover, the LolD motif was found to be critical for functional interplay with LolC/E, since some LolD mutations lowered the ATPase activity of LolCDE without affecting that of LolD.

scholarly journals Disruption of lolCDE, Encoding an ATP-Binding Cassette Transporter, Is Lethal for Escherichia coli and Prevents Release of Lipoproteins from the Inner Membrane

2002 ◽  
Vol 184 (5) ◽  
pp. 1417-1422 ◽  
Author(s):  
Shin-ichiro Narita ◽  
Kimie Tanaka ◽  
Shin-ichi Matsuyama ◽  
Hajime Tokuda
Keyword(s):  
Escherichia Coli ◽  
Outer Membrane ◽  
Amino Acid Sequences ◽  
Atp Binding ◽  
Nonpermissive Temperature ◽  
Inner Membrane ◽  
E Coli ◽  
Atp Binding Cassette Transporter ◽  
Membrane Lipoproteins ◽  
Atp Binding Cassette

ABSTRACT ATP-binding cassette transporter LolCDE was previously identified, by using reconstituted proteoliposomes, as an apparatus catalyzing the release of outer membrane-specific lipoproteins from the inner membrane of Escherichia coli. Mutations resulting in defective LolD were previously shown to be lethal for E. coli. The amino acid sequences of LolC and LolE are similar to each other, but the necessity of both proteins for lipoprotein release has not been proved. Moreover, previous reconstitution experiments did not clarify whether or not LolCDE is the sole apparatus for lipoprotein release. To address these issues, a chromosomal lolC-lolD-lolE null mutant harboring a helper plasmid that carries the lolCDE genes and a temperature-sensitive replicon was constructed. The mutant failed to grow at a nonpermissive temperature because of the depletion of LolCDE. In addition to functional LolD, both LolC and LolE were required for growth. At a nonpermissive temperature, the outer membrane lipoproteins were mislocalized in the inner membrane since LolCDE depletion inhibited the release of lipoproteins from the inner membrane. Furthermore, both LolC and LolE were essential for the release of lipoproteins. On the other hand, LolCDE depletion did not affect the translocation of a lipoprotein precursor across the inner membrane and subsequent processing to the mature lipoprotein. From these results, we conclude that the LolCDE complex is an essential ABC transporter for E. coli and the sole apparatus mediating the release of outer membrane lipoproteins from the inner membrane.

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.

scholarly journals The Conserved Glutamate Residue Adjacent to the Walker-B Motif Is the Catalytic Base for ATP Hydrolysis in the ATP-binding Cassette Transporter BmrA

2003 ◽  
Vol 278 (47) ◽  
pp. 47002-47008 ◽  
Author(s):  
Cédric Orelle ◽  
Olivier Dalmas ◽  
Philippe Gros ◽  
Attilio Di Pietro ◽  
Jean-Michel Jault
Keyword(s):  
Atp Hydrolysis ◽  
Atp Binding ◽  
Atp Binding Cassette Transporter ◽  
Atp Binding Cassette

scholarly journals Insect ATP-Binding Cassette (ABC) Transporters: Roles in Xenobiotic Detoxification and Bt Insecticidal Activity

2019 ◽  
Vol 20 (11) ◽  
pp. 2829 ◽  
Author(s):  
Chao Wu ◽  
Swapan Chakrabarty ◽  
Minghui Jin ◽  
Kaiyu Liu ◽  
Yutao Xiao
Keyword(s):  
Abc Transporter ◽  
Conformational Changes ◽  
Abc Transporters ◽  
Insecticidal Activity ◽  
Atp Hydrolysis ◽  
Atp Binding ◽  
Bt Toxin ◽  
Xenobiotic Detoxification ◽  
Binding Domains ◽  
Atp Binding Cassette

ATP-binding cassette (ABC) transporters, a large class of transmembrane proteins, are widely found in organisms and play an important role in the transport of xenobiotics. Insect ABC transporters are involved in insecticide detoxification and Bacillus thuringiensis (Bt) toxin perforation. The complete ABC transporter is composed of two hydrophobic transmembrane domains (TMDs) and two nucleotide binding domains (NBDs). Conformational changes that are needed for their action are mediated by ATP hydrolysis. According to the similarity among their sequences and organization of conserved ATP-binding cassette domains, insect ABC transporters have been divided into eight subfamilies (ABCA–ABCH). This review describes the functions and mechanisms of ABC transporters in insecticide detoxification, plant toxic secondary metabolites transport and insecticidal activity of Bt toxin. With improved understanding of the role and mechanisms of ABC transporter in resistance to insecticides and Bt toxins, we can identify valuable target sites for developing new strategies to control pests and manage resistance and achieve green pest control.

scholarly journals The ATP Hydrolysis Cycle of the Nucleotide-binding Domain of the Mitochondrial ATP-binding Cassette Transporter Mdl1p

2003 ◽  
Vol 278 (29) ◽  
pp. 26862-26869 ◽  
Author(s):  
Eva Janas ◽  
Matthias Hofacker ◽  
Min Chen ◽  
Simone Gompf ◽  
Chris van der Does ◽  
...  
Keyword(s):  
Atp Hydrolysis ◽  
Nucleotide Binding ◽  
Binding Domain ◽  
Atp Binding ◽  
Nucleotide Binding Domain ◽  
Atp Binding Cassette Transporter ◽  
Atp Binding Cassette

scholarly journals Overexpression and functional characterization of an ABC (ATP-binding cassette) transporter encoded by the genes drrA and drrB of Mycobacterium tuberculosis

2002 ◽  
Vol 367 (1) ◽  
pp. 279-285 ◽  
Author(s):  
Baisakhee Saha CHOUDHURI ◽  
Sanjib BHAKTA ◽  
Rajib BARIK ◽  
Joyoti BASU ◽  
Manikuntala KUNDU ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Abc Transporters ◽  
Efflux Pump ◽  
Functional Characterization ◽  
Atp Binding ◽  
E Coli ◽  
Neutral Compound ◽  
Genes Encoding ◽  
Simultaneous Expression ◽  
Atp Binding Cassette

The genes encoding ATP-binding cassette (ABC) transporters occupy 2.5% of the genome of Mycobacterium tuberculosis. However, none of these putative ABC transporters has been characterized so far. We describe the development of expression systems for simultaneous expression of the ATP-binding protein DrrA and the membrane integral protein DrrB which together behave as a functional doxorubicin efflux pump. Doxorubicin uptake in Escherichia coli or Mycobacterium smegmatis expressing DrrAB was inhibited by reserpine, an inhibitor of ABC transporters. The localization of DrrA to the membrane depended on the simultaneous expression of DrrB. ATP binding was positively regulated by doxorubicin and daunorubicin. At the same time, DrrB appeared to be sensitive to proteolysis when expressed alone in the absence of DrrA. Simultaneous expression of the two polypeptides was essential to obtain a functional doxorubicin efflux pump. Expression of DrrAB in E. coli conferred 8-fold increased resistance to ethidium bromide, a cationic compound. 2′,7′-bis-(2-Carboxyethyl)-5(6)-carboxyfluorescein (BCECF), a neutral compound, also behaved as a substrate of the reconstituted efflux pump. When expressed in M. smegmatis, DrrAB conferred resistance to a number of clinically relevant, structurally unrelated antibiotics. The resistant phenotype could be reversed by verapamil and reserpine, two potent inhibitors of ABC transporters.

scholarly journals Highly efficient over-production in E. coli of YvcC, a multidrug-like ATP-binding cassette transporter from Bacillus subtilis

2002 ◽  
Vol 1565 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Emmanuelle Steinfels ◽  
Cédric Orelle ◽  
Olivier Dalmas ◽  
François Penin ◽  
Bruno Miroux ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Atp Binding ◽  
E Coli ◽  
Highly Efficient ◽  
Atp Binding Cassette Transporter ◽  
Atp Binding Cassette

scholarly journals Abca7 deletion does not affect adult neurogenesis in the mouse

2016 ◽  
Vol 36 (2) ◽  
Author(s):  
Hongyun Li ◽  
Tim Karl ◽  
Brett Garner
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Adult Neurogenesis ◽  
Abc Transporters ◽  
Atp Binding ◽  
Wild Type ◽  
Atp Binding Cassette Transporter ◽  
The Brain ◽  
Deficient Mice ◽  
Atp Binding Cassette

ATP-binding cassette transporter A7 (ABCA7) is expressed in the brain and linked with Alzheimer's disease. Since other ABC transporters regulate adult neurogenesis, we assessed neurogenesis in wild-type (WT) and Abca7 deficient mice. Abca7 deletion did not affect adult neurogenesis in the mouse.

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