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

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.

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The Human ATP-Binding Cassette (ABC) Transporter Superfamily

10.22541/au.164001179.92800452/v1 ◽

2021 ◽

Author(s):

Michael Dean ◽

Karobi Moitra ◽

Rando Allikmets

Keyword(s):

Abc Transporter ◽

Abc Transporters ◽

Rare Variants ◽

Mendelian Inheritance ◽

Atp Binding ◽

Evolutionary Diversification ◽

Binding Domains ◽

Cholesterol Levels ◽

Human Disorders ◽

Atp Binding Cassette

The ATP-binding cassette (ABC) transporter superfamily comprises membrane proteins that efflux various substrates across extra- and intra-cellular membranes. Mutations in ABC genes cause 21 human disorders or phenotypes with Mendelian inheritance, including cystic fibrosis, adrenoleukodystrophy, retinal degeneration, cholesterol, and bile transport defects. Common polymorphisms and rare variants in ABC genes are associated with several complex phenotypes such as gout, gallstones, and cholesterol levels. Overexpression or amplification of specific drug efflux genes contributes to chemotherapy multidrug resistance. Conservation of the ATP-binding domains of ABC transporters defines the superfamily members, and phylogenetic analysis groups the 48 human ABC transporters into seven distinct subfamilies. While the conservation of ABC genes across most vertebrate species is high, there is also considerable gene duplication, deletion, and evolutionary diversification.

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Combining Mutations That Inhibit Two Distinct Steps of the ATP Hydrolysis Cycle Restores Wild-Type Function in the Lipopolysaccharide Transporter and Shows that ATP Binding Triggers Transport

mBio ◽

10.1128/mbio.01931-19 ◽

2019 ◽

Vol 10 (4) ◽

Cited By ~ 4

Author(s):

Brent W. Simpson ◽

Karanbir S. Pahil ◽

Tristan W. Owens ◽

Emily A. Lundstedt ◽

Rebecca M. Davis ◽

...

Keyword(s):

Abc Transporter ◽

Conformational Changes ◽

Abc Transporters ◽

Atp Binding ◽

Gram Negative Bacteria ◽

Wild Type ◽

Lethal Effects ◽

Gram Negative ◽

Binding Domains ◽

Transport Cycle

ABSTRACT ATP-binding cassette (ABC) transporters constitute a large family of proteins present in all domains of life. They are powered by dynamic ATPases that harness energy from binding and hydrolyzing ATP through a cycle that involves the closing and reopening of their two ATP-binding domains. The LptB2FGC exporter is an essential ABC transporter that assembles lipopolysaccharides (LPS) on the surface of Gram-negative bacteria to form a permeability barrier against many antibiotics. LptB2FGC extracts newly synthesized LPS molecules from the inner membrane and powers their transport across the periplasm and through the outer membrane. How LptB2FGC functions remains poorly understood. Here, we show that the C-terminal domain of the dimeric LptB ATPase is essential for LPS transport in Escherichia coli. Specific changes in the C-terminal domain of LptB cause LPS transport defects that can be repaired by intragenic suppressors altering the ATP-binding domains. Surprisingly, we found that each of two lethal changes in the ATP-binding and C-terminal domains of LptB, when present in combined form, suppressed the defects associated with the other to restore LPS transport to wild-type levels both in vivo and in vitro. We present biochemical evidence explaining the effect that each of these mutations has on LptB function and how the observed cosuppression results from the opposing lethal effects these changes have on the dimerization state of the LptB ATPase. We therefore propose that these sites modulate the closing and reopening of the LptB dimer, providing insight into how the LptB2FGC transporter cycles to export LPS to the cell surface and how to inhibit this essential envelope biogenesis process. IMPORTANCE Gram-negative bacteria are naturally resistant to many antibiotics because their surface is covered by the glycolipid LPS. Newly synthesized LPS is transported across the cell envelope by the multiprotein Lpt machinery, which includes LptB2FGC, an unusual ABC transporter that extracts LPS from the inner membrane. Like in other ABC transporters, the LptB2FGC transport cycle is driven by the cyclical conformational changes that a cytoplasmic, dimeric ATPase, LptB, undergoes when binding and hydrolyzing ATP. How these conformational changes are controlled in ABC transporters is poorly understood. Here, we identified two lethal changes in LptB that, when combined, remarkably restore wild-type transport function. Biochemical studies revealed that the two changes affect different steps in the transport cycle, having opposing, lethal effects on LptB’s dimerization cycle. Our work provides mechanistic details about the LptB2FGC extractor that could be used to develop Lpt inhibitors that would overcome the innate antibiotic resistance of Gram-negative bacteria.

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ATP-dependent thermostabilization of human P-glycoprotein (ABCB1) is blocked by modulators

Biochemical Journal ◽

10.1042/bcj20190736 ◽

2019 ◽

Vol 476 (24) ◽

pp. 3737-3750 ◽

Cited By ~ 5

Author(s):

Sabrina Lusvarghi ◽

Suresh V. Ambudkar

Keyword(s):

Conformational Changes ◽

Drug Transport ◽

Atp Hydrolysis ◽

Atp Binding ◽

Dependent Manner ◽

Deficient Mutant ◽

Concentration Dependent Manner ◽

Glycoprotein P ◽

Binding Domains ◽

P Glycoprotein

P-glycoprotein (P-gp), an ATP-binding cassette transporter associated with multidrug resistance in cancer cells, is capable of effluxing a number of xenobiotics as well as anticancer drugs. The transport of molecules through the transmembrane (TM) region of P-gp involves orchestrated conformational changes between inward-open and inward-closed forms, the details of which are still being worked out. Here, we assessed how the binding of transport substrates or modulators in the TM region and the binding of ATP to the nucleotide-binding domains (NBDs) affect the thermostability of P-gp in a membrane environment. P-gp stability after exposure at high temperatures (37–80°C) was assessed by measuring ATPase activity and loss of monomeric P-gp. Our results show that P-gp is significantly thermostabilized (>22°C higher IT50) by the binding of ATP under non-hydrolyzing conditions (in the absence of Mg2+). By using an ATP-binding-deficient mutant (Y401A) and a hydrolysis-deficient mutant (E556Q/E1201Q), we show that thermostabilization of P-gp requires binding of ATP to both NBDs and their dimerization. Additionally, we found that transport substrates do not affect the thermal stability of P-gp either in the absence or presence of ATP; in contrast, inhibitors of P-gp including tariquidar and zosuquidar prevent ATP-dependent thermostabilization in a concentration-dependent manner, by stabilizing the inward-open conformation. Altogether, our data suggest that modulators, which bind in the TM regions, inhibit ATP hydrolysis and drug transport by preventing the ATP-dependent dimerization of the NBDs of P-gp.

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

International Journal of Molecular Sciences ◽

10.3390/ijms20133178 ◽

2019 ◽

Vol 20 (13) ◽

pp. 3178 ◽

Cited By ~ 3

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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Human ATP-Binding Cassette Transporter TaqMan Low-Density Array: Analysis of Macrophage Differentiation and Foam Cell Formation

Clinical Chemistry ◽

10.1373/clinchem.2005.059774 ◽

2006 ◽

Vol 52 (2) ◽

pp. 310-313 ◽

Cited By ~ 39

Author(s):

Thomas Langmann ◽

Richard Mauerer ◽

Gerd Schmitz

Keyword(s):

Multidrug Resistance ◽

Abc Transporter ◽

Abc Transporters ◽

Metabolic Regulation ◽

Foam Cell ◽

Expression Patterns ◽

Foam Cell Formation ◽

Atp Binding ◽

Low Density ◽

Atp Binding Cassette

Abstract Background: ATP-binding cassette (ABC) transporters cause various diseases and regulate many physiologic processes, such as lipid homeostasis, iron transport, and immune mechanisms. Several ABC transporters are involved in bile acid, phospholipid, and sterol transport, and their expression is itself controlled by lipids. In addition, ABC proteins mediate drug export in tumor cells and promote the development of multidrug resistance. Methods: We created an ABC Transporter TaqMan Low-Density Array based on an Applied Biosystems 7900HT Micro Fluidic Card. We used a 2-μL reaction well with 2 ng of sample. To evaluate this method for lipidomic research and to characterize expression patterns of ABC transporters in cells relevant for atherosclerosis research, we monitored mRNA expression in human primary monocytes, in vitro–differentiated macrophages, and cells stimulated with the liver-X-receptor and retinoid-X-receptor agonists T0901317 and 9-cis retinoic acid, mimicking sterol loading. Results: The method enabled simultaneous analysis of 47 human ABC transporters and the reference gene 18S rRNA in 2 replicates of 4 samples per run. Conclusions: The new system uses only 2 ng of sample and small volumes of reagent, and the precaptured primers and probes avoided labor-intensive pipetting steps. The ABC Transporter TaqMan Low-Density Array may be a useful tool to monitor dysregulated ABC transporter mRNA profiles in human lipid disorders and cancer-related multidrug resistance and to analyze the pharmacologic and metabolic regulation of ABC transporter expression important for drug development in large-scale screening approaches.

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Structural and functional insights into the Diabrotica virgifera virgifera ATP-binding cassette transporter gene family

BMC Genomics ◽

10.1186/s12864-019-6218-8 ◽

2019 ◽

Vol 20 (1) ◽

Author(s):

Folukemi Adedipe ◽

Nathaniel Grubbs ◽

Brad Coates ◽

Brian Wiegmman ◽

Marcé Lorenzen

Keyword(s):

Abc Transporter ◽

Abc Transporters ◽

Sequence Data ◽

Transcriptome Assembly ◽

Diabrotica Virgifera Virgifera ◽

Atp Binding ◽

Pest Species ◽

Diabrotica Virgifera ◽

Transporter Family ◽

Atp Binding Cassette

Abstract Background The western corn rootworm, Diabrotica virgifera virgifera, is a pervasive pest of maize in North America and Europe, which has adapted to current pest management strategies. In advance of an assembled and annotated D. v. virgifera genome, we developed transcriptomic resources to use in identifying candidate genes likely to be involved in the evolution of resistance, starting with members of the ATP-binding cassette (ABC) transporter family. Results In this study, 65 putative D. v. virgifera ABC (DvvABC) transporters were identified within a combined transcriptome assembly generated from embryonic, larval, adult male, and adult female RNA-sequence libraries. Phylogenetic analysis placed the deduced amino-acid sequences of the DvvABC transporters into eight subfamilies (A to H). To supplement our sequence data with functional analysis, we identified orthologs of Tribolium castaneum ABC genes which had previously been shown to exhibit overt RNA interference (RNAi) phenotypes. We identified eight such D. v. virgifera genes, and found that they were functionally similar to their T. castaneum counterparts. Interestingly, depletion of DvvABCB_39715 and DvvABCG_3712 transcripts in adult females produced detrimental reproductive and developmental phenotypes, demonstrating the potential of these genes as targets for RNAi-mediated insect control tactics. Conclusions By combining sequence data from four libraries covering three distinct life stages, we have produced a relatively comprehensive de novo transcriptome assembly for D. v. virgifera. Moreover, we have identified 65 members of the ABC transporter family and provided the first insights into the developmental and physiological roles of ABC transporters in this pest species.

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In vivo FRET analyses reveal a role of ATP hydrolysis–associated conformational changes in human P-glycoprotein

Journal of Biological Chemistry ◽

10.1074/jbc.ra119.012042 ◽

2020 ◽

Vol 295 (15) ◽

pp. 5002-5011 ◽

Cited By ~ 4

Author(s):

Ryota Futamata ◽

Fumihiko Ogasawara ◽

Takafumi Ichikawa ◽

Atsushi Kodan ◽

Yasuhisa Kimura ◽

...

Keyword(s):

Conformational Changes ◽

Drug Transport ◽

Atp Hydrolysis ◽

Hek293 Cells ◽

Atp Binding ◽

Binding Domains ◽

P Glycoprotein ◽

Atp Binding And Hydrolysis

P-glycoprotein (P-gp; also known as MDR1 or ABCB1) is an ATP-driven multidrug transporter that extrudes various hydrophobic toxic compounds to the extracellular space. P-gp consists of two transmembrane domains (TMDs) that form the substrate translocation pathway and two nucleotide-binding domains (NBDs) that bind and hydrolyze ATP. At least two P-gp states are required for transport. In the inward-facing (pre-drug transport) conformation, the two NBDs are separated, and the two TMDs are open to the intracellular side; in the outward-facing (post-drug transport) conformation, the NBDs are dimerized, and the TMDs are slightly open to the extracellular side. ATP binding and hydrolysis cause conformational changes between the inward-facing and the outward-facing conformations, and these changes help translocate substrates across the membrane. However, how ATP hydrolysis is coupled to these conformational changes remains unclear. In this study, we used a new FRET sensor that detects conformational changes in P-gp to investigate the role of ATP binding and hydrolysis during the conformational changes of human P-gp in living HEK293 cells. We show that ATP binding causes the conformational change to the outward-facing state and that ATP hydrolysis and subsequent release of γ-phosphate from both NBDs allow the outward-facing state to return to the original inward-facing state. The findings of our study underscore the utility of using FRET analysis in living cells to elucidate the function of membrane proteins such as multidrug transporters.

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Learning the ABCs one at a time: structure and mechanism of ABC transporters

Biochemical Society Transactions ◽

10.1042/bst20180147 ◽

2019 ◽

Vol 47 (1) ◽

pp. 23-36 ◽

Cited By ~ 36

Author(s):

Robert C. Ford ◽

Konstantinos Beis

Keyword(s):

Abc Transporters ◽

Atp Hydrolysis ◽

Atp Binding ◽

Bacterial Cells ◽

The Novel ◽

Mechanism Model ◽

Binding Domains ◽

Atp Binding And Hydrolysis ◽

Alternating Access

Abstract ATP-binding cassette (ABC) transporters are essential proteins that are found across all kingdoms of life. ABC transporters harness the energy of ATP hydrolysis to drive the import of nutrients inside bacterial cells or the export of toxic compounds or essential lipids across bacteria and eukaryotic membranes. Typically, ABC transporters consist of transmembrane domains (TMDs) and nucleotide-binding domains (NBDs) to bind their substrate and ATP, respectively. The TMDs dictate what ligands can be recognised, whereas the NBDs are the power engine of the ABC transporter, carrying out ATP binding and hydrolysis. It has been proposed that they utilise the alternating access mechanism, inward- to outward-facing conformation, to transport their substrates. Here, we will review the recent progress on the structure determination of eukaryotic and bacterial ABC transporters as well as the novel mechanisms that have also been proposed, that fall out of the alternating access mechanism model.

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In Silico Genome-Wide Analysis of the ATP-Binding Cassette Transporter Gene Family in Soybean (Glycine max L.) and Their Expression Profiling

BioMed Research International ◽

10.1155/2019/8150523 ◽

2019 ◽

Vol 2019 ◽

pp. 1-14 ◽

Cited By ~ 2

Author(s):

Awdhesh Kumar Mishra ◽

Jinhee Choi ◽

Muhammad Fazle Rabbee ◽

Kwang-Hyun Baek

Keyword(s):

Gene Family ◽

Abc Transporter ◽

Abc Transporters ◽

In Silico ◽

Gene Families ◽

Protein Domain ◽

Atp Binding ◽

Transporter Gene ◽

Genome Wide ◽

Atp Binding Cassette

ATP-binding cassette (ABC) transporters constitute one of the largest gene families in all living organisms, most of which mediate transport across biological membranes by hydrolyzing ATP. However, detailed studies of ABC transporter genes in the important oil crop, soybean, are still lacking. In the present study, we carried out genome-wide identification and phylogenetic and transcriptional analyses of the ABC gene family in G. max. A total of 261 G. max ABC (GmABCs) genes were identified and unevenly localized onto 20 chromosomes. Referring to protein-domain orientation and phylogeny, the GmABC family could be classified into eight (ABCA-ABCG and ABCI) subfamilies and ABCG were the most abundantly present. Further, investigation of whole genome duplication (WGD) signifies the role of segmental duplication in the expansion of the ABC transporter gene family in soybean. The Ka/Ks ratio indicates that several duplicated genes are governed by intense purifying selection during evolution. In addition, in silico expression analysis based on RNA-sequence using publicly available database revealed that ABC transporters are differentially expressed in tissues and developmental stages and in dehydration. Overall, we provide an extensive overview of the GmABC transporter gene family and it promises the primary basis for the study in development and response to dehydration tolerance.

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Association/Dissociation of the Nucleotide-binding Domains of the ATP-binding Cassette Protein MsbA Measured during Continuous Hydrolysis

Journal of Biological Chemistry ◽

10.1074/jbc.m113.477976 ◽

2013 ◽

Vol 288 (29) ◽

pp. 20785-20796 ◽

Cited By ~ 32

Author(s):

Rebecca S. Cooper ◽

Guillermo A. Altenberg

Keyword(s):

Atp Hydrolysis ◽

Resonance Energy Transfer ◽

Resonance Energy ◽

Nucleotide Binding ◽

Atp Binding ◽

Binding Domains ◽

Partial Opening ◽

Contact Models ◽

Bacterial Lipid ◽

Atp Binding Cassette

In ATP-binding cassette proteins, the two nucleotide-binding domains (NBDs) work as dimers to bind and hydrolyze ATP, but the molecular mechanism of nucleotide hydrolysis is controversial. It is still unresolved whether hydrolysis leads to dissociation of the ATP-induced dimers or partial opening of the dimers such that the NBDs remain in contact during the hydrolysis cycle. We studied the bacterial lipid flippase MsbA by luminescence resonance energy transfer (LRET). The LRET signal between optical probes reacted with single-cysteine mutants was employed to follow NBD association/dissociation in real time. The intermonomer distances calculated from LRET data indicate that the NBDs separate completely following ATP hydrolysis, even in the presence of mm MgATP, and that the dissociation occurs following each hydrolysis cycle. The results support association/dissociation, as opposed to constant contact models, for the mode of operation of ATP-binding cassette proteins.

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