1
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Stoeltje L, Luc JK, Haddad T, Schrankel CS. The roles of ABCB1/P-glycoprotein drug transporters in regulating gut microbes and inflammation: insights from animal models, old and new. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230074. [PMID: 38497255 PMCID: PMC10945405 DOI: 10.1098/rstb.2023.0074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 02/13/2024] [Indexed: 03/19/2024] Open
Abstract
Commensal enteric bacteria have evolved systems that enable growth in the ecologic niche of the host gastrointestinal tract. Animals evolved parallel mechanisms to survive the constant exposure to bacteria and their metabolic by-products. We propose that drug transporters encompass a crucial system to managing the gut microbiome. Drug transporters are present in the apical surface of gut epithelia. They detoxify cells from small molecules and toxins (xenobiotics) in the lumen. Here, we review what is known about commensal structure in the absence of the transporter ABCB1/P-glycoprotein in mammalian models. Knockout or low-activity alleles of ABCB1 lead to dysbiosis, Crohn's disease and ulcerative colitis in mammals. However, the exact function of ABCB1 in these contexts remain unclear. We highlight emerging models-the zebrafish Danio rerio and sea urchin Lytechinus pictus-that are poised to help dissect the fundamental mechanisms of ATP-binding cassette (ABC) transporters in the tolerance of commensal and pathogenic communities in the gut. We and others hypothesize that ABCB1 plays a direct role in exporting inflammatory bacterial products from host epithelia. Interdisciplinary work in this research area will lend novel insight to the transporter-mediated pathways that impact microbiome community structure and accelerate the pathogenesis of inflammatory bowel disease when perturbed. This article is part of the theme issue 'Sculpting the microbiome: how host factors determine and respond to microbial colonization'.
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Affiliation(s)
- Lauren Stoeltje
- Department of Biology, San Diego State University, 5500 Campanile Drive, Life Sciences North, Room 321, San Diego, CA 92182, USA
| | - Jenna K. Luc
- Department of Biology, San Diego State University, 5500 Campanile Drive, Life Sciences North, Room 321, San Diego, CA 92182, USA
| | - Timothaus Haddad
- Department of Biology, San Diego State University, 5500 Campanile Drive, Life Sciences North, Room 321, San Diego, CA 92182, USA
| | - Catherine S. Schrankel
- Department of Biology, San Diego State University, 5500 Campanile Drive, Life Sciences North, Room 321, San Diego, CA 92182, USA
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2
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Ni C, Hong M. Oligomerization of drug transporters: Forms, functions, and mechanisms. Acta Pharm Sin B 2024; 14:1924-1938. [PMID: 38799641 PMCID: PMC11119549 DOI: 10.1016/j.apsb.2024.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 12/07/2023] [Accepted: 01/05/2024] [Indexed: 05/29/2024] Open
Abstract
Drug transporters are essential players in the transmembrane transport of a wide variety of clinical drugs. The broad substrate spectra and versatile distribution pattern of these membrane proteins infer their pharmacological and clinical significance. With our accumulating knowledge on the three-dimensional structure of drug transporters, their oligomerization status has become a topic of intense study due to the possible functional roles carried out by such kind of post-translational modification (PTM). In-depth studies of oligomeric complexes formed among drug transporters as well as their interactions with other regulatory proteins can help us better understand the regulatory mechanisms of these membrane proteins, provide clues for the development of novel drugs, and improve the therapeutic efficacy. In this review, we describe different oligomerization forms as well as their structural basis of major drug transporters in the ATP-binding cassette and solute carrier superfamilies, summarize our current knowledge on the influence of oligomerization for protein expression level and transport function of these membrane proteins, and discuss the regulatory mechanisms of oligomerization. Finally, we highlight the challenges associated with the current oligomerization studies and propose some thoughts on the pharmaceutical application of this important drug transporter PTM.
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Affiliation(s)
- Chunxu Ni
- College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Mei Hong
- College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, South China Agricultural University, Guangzhou 510642, China
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3
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Rong Z, Zheng K, Chen J, Jin X. The cross talk of ubiquitination and chemotherapy tolerance in colorectal cancer. J Cancer Res Clin Oncol 2024; 150:154. [PMID: 38521878 PMCID: PMC10960765 DOI: 10.1007/s00432-024-05659-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 02/20/2024] [Indexed: 03/25/2024]
Abstract
Ubiquitination, a highly adaptable post-translational modification, plays a pivotal role in maintaining cellular protein homeostasis, encompassing cancer chemoresistance-associated proteins. Recent findings have indicated a potential correlation between perturbations in the ubiquitination process and the emergence of drug resistance in CRC cancer. Consequently, numerous studies have spurred the advancement of compounds specifically designed to target ubiquitinates, offering promising prospects for cancer therapy. In this review, we highlight the role of ubiquitination enzymes associated with chemoresistance to chemotherapy via the Wnt/β-catenin signaling pathway, epithelial-mesenchymal transition (EMT), and cell cycle perturbation. In addition, we summarize the application and role of small compounds that target ubiquitination enzymes for CRC treatment, along with the significance of targeting ubiquitination enzymes as potential cancer therapies.
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Affiliation(s)
- Ze Rong
- Department of Chemoradiotherapy, the Affiliated People's Hospital of Ningbo University, Ningbo, 315040, China.
| | - Kaifeng Zheng
- Department of Chemoradiotherapy, the Affiliated People's Hospital of Ningbo University, Ningbo, 315040, China
| | - Jun Chen
- Department of Chemoradiotherapy, the Affiliated People's Hospital of Ningbo University, Ningbo, 315040, China.
| | - Xiaofeng Jin
- Department of Chemoradiotherapy, the Affiliated People's Hospital of Ningbo University, Ningbo, 315040, China.
- Department of Biochemistry and Molecular Biology, Health Science Center, Ningbo, 315211, China.
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4
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Ying W, Wang Y, Wei H, Luo Y, Ma Q, Zhu H, Janssens H, Vukašinović N, Kvasnica M, Winne JM, Gao Y, Tan S, Friml J, Liu X, Russinova E, Sun L. Structure and function of the Arabidopsis ABC transporter ABCB19 in brassinosteroid export. Science 2024; 383:eadj4591. [PMID: 38513023 DOI: 10.1126/science.adj4591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 02/02/2024] [Indexed: 03/23/2024]
Abstract
Brassinosteroids are steroidal phytohormones that regulate plant development and physiology, including adaptation to environmental stresses. Brassinosteroids are synthesized in the cell interior but bind receptors at the cell surface, necessitating a yet to be identified export mechanism. Here, we show that a member of the ATP-binding cassette (ABC) transporter superfamily, ABCB19, functions as a brassinosteroid exporter. We present its structure in both the substrate-unbound and the brassinosteroid-bound states. Bioactive brassinosteroids are potent activators of ABCB19 ATP hydrolysis activity, and transport assays showed that ABCB19 transports brassinosteroids. In Arabidopsis thaliana, ABCB19 and its close homolog, ABCB1, positively regulate brassinosteroid responses. Our results uncover an elusive export mechanism for bioactive brassinosteroids that is tightly coordinated with brassinosteroid signaling.
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Affiliation(s)
- Wei Ying
- Department of Neurology of The First Affiliated Hospital of USTC, MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Research Center for Physical Sciences at the Microscale, Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Yaowei Wang
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Hong Wei
- Department of Neurology of The First Affiliated Hospital of USTC, MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Research Center for Physical Sciences at the Microscale, Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Yongming Luo
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Qian Ma
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Heyuan Zhu
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Hilde Janssens
- Department of Organic and Macromolecular Chemistry, Ghent University, 9000 Ghent, Belgium
| | - Nemanja Vukašinović
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Miroslav Kvasnica
- Laboratory of Growth Regulators, Institute of Experimental Botany, The Czech Academy of Sciences and Palacký University, 77900 Olomouc, Czech Republic
| | - Johan M Winne
- Department of Organic and Macromolecular Chemistry, Ghent University, 9000 Ghent, Belgium
| | - Yongxiang Gao
- Department of Neurology of The First Affiliated Hospital of USTC, MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Research Center for Physical Sciences at the Microscale, Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Shutang Tan
- Department of Neurology of The First Affiliated Hospital of USTC, MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Research Center for Physical Sciences at the Microscale, Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Jiří Friml
- Institute of Science and Technology Austria (ISTA), 3400 Klosterneuburg, Austria
| | - Xin Liu
- Department of Neurology of The First Affiliated Hospital of USTC, MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Research Center for Physical Sciences at the Microscale, Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Eugenia Russinova
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Linfeng Sun
- Department of Neurology of The First Affiliated Hospital of USTC, MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Research Center for Physical Sciences at the Microscale, Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
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5
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Gao Y, Wei C, Luo L, Tang Y, Yu Y, Li Y, Xing J, Pan X. Membrane-assisted tariquidar access and binding mechanisms of human ATP-binding cassette transporter P-glycoprotein. Front Mol Biosci 2024; 11:1364494. [PMID: 38560519 PMCID: PMC10979361 DOI: 10.3389/fmolb.2024.1364494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 02/20/2024] [Indexed: 04/04/2024] Open
Abstract
The human multidrug transporter P-glycoprotein (P-gp) is physiologically essential and of key relevance to biomedicine. Recent structural studies have shed light on the mode of inhibition of the third-generation inhibitors for human P-gp, but the molecular mechanism by which these inhibitors enter the transmembrane sites remains poorly understood. In this study, we utilized all-atom molecular dynamics (MD) simulations to characterize human P-gp dynamics under a potent inhibitor, tariquidar, bound condition, as well as the atomic-level binding pathways in an explicit membrane/water environment. Extensive unbiased simulations show that human P-gp remains relatively stable in tariquidar-free and bound states, while exhibiting a high dynamic binding mode at either the drug-binding pocket or the regulatory site. Free energy estimations by partial nudged elastic band (PNEB) simulations and Molecular Mechanics Generalized Born Surface Area (MM/GBSA) method identify two energetically favorable binding pathways originating from the cytoplasmic gate with an extended tariquidar conformation. Interestingly, free tariquidar in the lipid membrane predominantly adopts extended conformations similar to those observed at the regulatory site. These results suggest that membrane lipids may preconfigure tariquidar into an active ligand conformation for efficient binding to the regulatory site. However, due to its conformational plasticity, tariquidar ultimately moves toward the drug-binding pocket in both pathways, explaining how it acts as a substrate at low concentrations. Our molecular findings propose a membrane-assisted mechanism for the access and binding of the third-generation inhibitors to the binding sites of human P-gp, and offer deeper insights into the molecule design of more potent inhibitors against P-gp-mediated drug resistance.
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Affiliation(s)
- Yingjie Gao
- Department of Medicinal Chemistry, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
| | - Caiyan Wei
- Department of Medicinal Chemistry, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
| | - Lanxin Luo
- Department of Pathophysiology, School of Basic Medical Science, Southwest Medical University, Luzhou, Sichuan, China
| | - Yang Tang
- Department of Medicinal Chemistry, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
| | - Yongzhen Yu
- Department of Medicinal Chemistry, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
| | - Yaling Li
- Department of Pharmacy, The Affiliated Hospital, Southwest Medical University, Luzhou, Sichuan, China
| | - Juan Xing
- Department of Pathophysiology, School of Basic Medical Science, Southwest Medical University, Luzhou, Sichuan, China
| | - Xianchao Pan
- Department of Medicinal Chemistry, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
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6
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Governa P, Biagi M, Manetti F, Forli S. Consensus screening for a challenging target: the quest for P-glycoprotein inhibitors. RSC Med Chem 2024; 15:720-732. [PMID: 38389870 PMCID: PMC10880898 DOI: 10.1039/d3md00649b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 01/18/2024] [Indexed: 02/24/2024] Open
Abstract
ATP-binding cassette (ABC) transporters are a large family of proteins involved in membrane transport of a wide variety of substrates. Among them, ABCB1, also known as MDR-1 or P-glycoprotein (P-gp), is the most characterized. By exporting xenobiotics out of the cell, P-gp activity can affect the ADME properties of several drugs. Moreover, P-gp has been found to mediate multidrug resistance in cancer cells. Thus, the inhibition of P-gp activity may lead to increased absorption and/or intracellular accumulation of co-administered drugs, enhancing their effectiveness. Using the human-mouse chimeric cryoEM 3D structure of the P-gp in the inhibitor-bound intermediate form (PDBID: 6qee), approximately 200 000 commercially available natural compounds from the ZINC database were virtually screened. To build a model able to discriminate between substrate and inhibitors, two datasets of compounds with known activity, including P-gp inhibitors, substrates, and inactive molecules were also docked. The best docking pose of selected substrates and inhibitors were used to generate 3D common feature pharmacophoric models that were combined with the Autodock Vina binding energy values to prioritize compounds for visual inspection. With this consensus approach, 13 potential candidates were identified and then tested for their ability to inhibit P-gp, using zosuquidar, a third generation P-gp inhibitor, as a reference drug. Eight compounds were found to be active with 6 of them having an IC50 lower than 5 μM in a membrane-based ATPase activity assay. Moreover, the P-gp inhibitory activity was also confirmed by two different cell-based in vitro methods. Both retrospective and prospective results demonstrate the ability of the combined structure-based pharmacophore modeling and docking-based virtual screening approach to predict novel hit compounds with inhibitory activity toward P-gp. The resulting chemical scaffolds could serve as inspiration for the optimization of novel and more potent P-gp inhibitors.
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Affiliation(s)
- Paolo Governa
- Department of Integrative Structural and Computational Biology, Scripps Research Institute La Jolla CA 92037 USA
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena 53100 Siena Italy
| | - Marco Biagi
- Department of Food and Drug, University of Parma 43121 Parma Italy
| | - Fabrizio Manetti
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena 53100 Siena Italy
| | - Stefano Forli
- Department of Integrative Structural and Computational Biology, Scripps Research Institute La Jolla CA 92037 USA
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7
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Kou X, Zhao Z, Xu X, Li C, Wu J, Zhang S. Identification and expression analysis of ATP-binding cassette (ABC) transporters revealed its role in regulating stress response in pear (Pyrus bretchneideri). BMC Genomics 2024; 25:169. [PMID: 38347517 PMCID: PMC10863237 DOI: 10.1186/s12864-024-10063-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Accepted: 01/29/2024] [Indexed: 02/15/2024] Open
Abstract
BACKGROUND ATP-binding cassette (ABC) transporter proteins constitute a plant gene superfamily crucial for growth, development, and responses to environmental stresses. Despite their identification in various plants like maize, rice, and Arabidopsis, little is known about the information on ABC transporters in pear. To investigate the functions of ABC transporters in pear development and abiotic stress response, we conducted an extensive analysis of ABC gene family in the pear genome. RESULTS In this study, 177 ABC transporter genes were successfully identified in the pear genome, classified into seven subfamilies: 8 ABCAs, 40 ABCBs, 24 ABCCs, 8 ABCDs, 9 ABCEs, 8 ABCFs, and 80 ABCGs. Ten motifs were common among all ABC transporter proteins, while distinct motif structures were observed for each subfamily. Distribution analysis revealed 85 PbrABC transporter genes across 17 chromosomes, driven primarily by WGD and dispersed duplication. Cis-regulatory element analysis of PbrABC promoters indicated associations with phytohormones and stress responses. Tissue-specific expression profiles demonstrated varied expression levels across tissues, suggesting diverse functions in development. Furthermore, several PbrABC genes responded to abiotic stresses, with 82 genes sensitive to salt stress, including 40 upregulated and 23 downregulated genes. Additionally, 91 genes were responsive to drought stress, with 22 upregulated and 36 downregulated genes. These findings highlight the pivotal role of PbrABC genes in abiotic stress responses. CONCLUSION This study provides evolutionary insights into PbrABC transporter genes, establishing a foundation for future research on their functions in pear. The identified motifs, distribution patterns, and stress-responsive expressions contribute to understanding the regulatory mechanisms of ABC transporters in pear. The observed tissue-specific expression profiles suggest diverse roles in developmental processes. Notably, the significant responses to salt and drought stress emphasize the importance of PbrABC genes in mediating adaptive responses. Overall, our study advances the understanding of PbrABC transporter genes in pear, opening avenues for further investigations in plant molecular biology and stress physiology.
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Affiliation(s)
- Xiaobing Kou
- School of Life Sciences, Nantong University, Nantong, 226019, Jiangsu, People's Republic of China.
| | - Zhen Zhao
- Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xinqi Xu
- School of Life Sciences, Nantong University, Nantong, 226019, Jiangsu, People's Republic of China
| | - Chang Li
- School of Life Sciences, Nantong University, Nantong, 226019, Jiangsu, People's Republic of China
| | - Juyou Wu
- Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Shaoling Zhang
- Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.
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8
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Sajid A, Rahman H, Ambudkar SV. Advances in the structure, mechanism and targeting of chemoresistance-linked ABC transporters. Nat Rev Cancer 2023; 23:762-779. [PMID: 37714963 DOI: 10.1038/s41568-023-00612-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/31/2023] [Indexed: 09/17/2023]
Abstract
Cancer cells frequently display intrinsic or acquired resistance to chemically diverse anticancer drugs, limiting therapeutic success. Among the main mechanisms of this multidrug resistance is the overexpression of ATP-binding cassette (ABC) transporters that mediate drug efflux, and, specifically, ABCB1, ABCG2 and ABCC1 are known to cause cancer chemoresistance. High-resolution structures, biophysical and in silico studies have led to tremendous progress in understanding the mechanism of drug transport by these ABC transporters, and several promising therapies, including irradiation-based immune and thermal therapies, and nanomedicine have been used to overcome ABC transporter-mediated cancer chemoresistance. In this Review, we highlight the progress achieved in the past 5 years on the three transporters, ABCB1, ABCG2 and ABCC1, that are known to be of clinical importance. We address the molecular basis of their broad substrate specificity gleaned from structural information and discuss novel approaches to block the function of ABC transporters. Furthermore, genetic modification of ABC transporters by CRISPR-Cas9 and approaches to re-engineer amino acid sequences to change the direction of transport from efflux to import are briefly discussed. We suggest that current information regarding the structure, mechanism and regulation of ABC transporters should be used in clinical trials to improve the efficiency of chemotherapeutics for patients with cancer.
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Affiliation(s)
- Andaleeb Sajid
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Hadiar Rahman
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Suresh V Ambudkar
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
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9
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Hu P, Liu Y, Zhu X, Kang H. ABCC Transporter Gene MoABC-R1 Is Associated with Pyraclostrobin Tolerance in Magnaporthe oryzae. J Fungi (Basel) 2023; 9:917. [PMID: 37755025 PMCID: PMC10532721 DOI: 10.3390/jof9090917] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 08/31/2023] [Accepted: 09/05/2023] [Indexed: 09/28/2023] Open
Abstract
Rice blast is a worldwide fungal disease that poses a threat to food security. Fungicide treatment is one of the most effective methods to control rice blast disease. However, the emergence of fungicide tolerance hampers the control efforts against rice blast. ATP-binding cassette (ABC) transporters have been found to be crucial in multidrug tolerance in various phytopathogenic fungi. This study investigated the association between polymorphisms in 50 ABC transporters and pyraclostrobin sensitivity in 90 strains of rice blast fungus. As a result, we identified MoABC-R1, a gene associated with fungicide tolerance. MoABC-R1 belongs to the ABCC-type transporter families. Deletion mutants of MoABC-R1, abc-r1, exhibited high sensitivity to pyraclostrobin at the concentration of 0.01 μg/mL. Furthermore, the pathogenicity of abc-r1 was significantly diminished. These findings indicate that MoABC-R1 not only plays a pivotal role in fungicide tolerance but also regulates the pathogenicity of rice blast. Interestingly, the combination of MoABC-R1 deletion with fungicide treatment resulted in a three-fold increase in control efficiency against rice blast. This discovery highlights MoABC-R1 as a potential target gene for the management of rice blast.
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Affiliation(s)
| | | | | | - Houxiang Kang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (P.H.); (Y.L.); (X.Z.)
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10
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Badiee SA, Isu UH, Khodadadi E, Moradi M. The Alternating Access Mechanism in Mammalian Multidrug Resistance Transporters and Their Bacterial Homologs. MEMBRANES 2023; 13:568. [PMID: 37367772 DOI: 10.3390/membranes13060568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 05/23/2023] [Accepted: 05/27/2023] [Indexed: 06/28/2023]
Abstract
Multidrug resistance (MDR) proteins belonging to the ATP-Binding Cassette (ABC) transporter group play a crucial role in the export of cytotoxic drugs across cell membranes. These proteins are particularly fascinating due to their ability to confer drug resistance, which subsequently leads to the failure of therapeutic interventions and hinders successful treatments. One key mechanism by which multidrug resistance (MDR) proteins carry out their transport function is through alternating access. This mechanism involves intricate conformational changes that enable the binding and transport of substrates across cellular membranes. In this extensive review, we provide an overview of ABC transporters, including their classifications and structural similarities. We focus specifically on well-known mammalian multidrug resistance proteins such as MRP1 and Pgp (MDR1), as well as bacterial counterparts such as Sav1866 and lipid flippase MsbA. By exploring the structural and functional features of these MDR proteins, we shed light on the roles of their nucleotide-binding domains (NBDs) and transmembrane domains (TMDs) in the transport process. Notably, while the structures of NBDs in prokaryotic ABC proteins, such as Sav1866, MsbA, and mammalian Pgp, are identical, MRP1 exhibits distinct characteristics in its NBDs. Our review also emphasizes the importance of two ATP molecules for the formation of an interface between the two binding sites of NBD domains across all these transporters. ATP hydrolysis occurs following substrate transport and is vital for recycling the transporters in subsequent cycles of substrate transportation. Specifically, among the studied transporters, only NBD2 in MRP1 possesses the ability to hydrolyze ATP, while both NBDs of Pgp, Sav1866, and MsbA are capable of carrying out this reaction. Furthermore, we highlight recent advancements in the study of MDR proteins and the alternating access mechanism. We discuss the experimental and computational approaches utilized to investigate the structure and dynamics of MDR proteins, providing valuable insights into their conformational changes and substrate transport. This review not only contributes to an enhanced understanding of multidrug resistance proteins but also holds immense potential for guiding future research and facilitating the development of effective strategies to overcome multidrug resistance, thus improving therapeutic interventions.
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Affiliation(s)
- Shadi A Badiee
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA
| | - Ugochi H Isu
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA
| | - Ehsaneh Khodadadi
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA
| | - Mahmoud Moradi
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA
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11
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Meier G, Thavarasah S, Ehrenbolger K, Hutter CAJ, Hürlimann LM, Barandun J, Seeger MA. Deep mutational scan of a drug efflux pump reveals its structure-function landscape. Nat Chem Biol 2023; 19:440-450. [PMID: 36443574 PMCID: PMC7615509 DOI: 10.1038/s41589-022-01205-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 10/10/2022] [Indexed: 11/30/2022]
Abstract
Drug efflux is a common resistance mechanism found in bacteria and cancer cells, but studies providing comprehensive functional insights are scarce. In this study, we performed deep mutational scanning (DMS) on the bacterial ABC transporter EfrCD to determine the drug efflux activity profile of more than 1,430 single variants. These systematic measurements revealed that the introduction of negative charges at different locations within the large substrate binding pocket results in strongly increased efflux activity toward positively charged ethidium, whereas additional aromatic residues did not display the same effect. Data analysis in the context of an inward-facing cryogenic electron microscopy structure of EfrCD uncovered a high-affinity binding site, which releases bound drugs through a peristaltic transport mechanism as the transporter transits to its outward-facing conformation. Finally, we identified substitutions resulting in rapid Hoechst influx without affecting the efflux activity for ethidium and daunorubicin. Hence, single mutations can convert EfrCD into a drug-specific ABC importer.
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Affiliation(s)
- Gianmarco Meier
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
| | - Sujani Thavarasah
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
| | - Kai Ehrenbolger
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Department of Molecular Biology, Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
- Science for Life Laboratory, Umeå University, Umeå, Sweden
| | - Cedric A J Hutter
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
- Linkster Therapeutics AG, Zurich, Switzerland
| | - Lea M Hürlimann
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
- Linkster Therapeutics AG, Zurich, Switzerland
| | - Jonas Barandun
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Department of Molecular Biology, Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
- Science for Life Laboratory, Umeå University, Umeå, Sweden
| | - Markus A Seeger
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland.
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12
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Martins-Gomes C, Silva AM. Natural Products as a Tool to Modulate the Activity and Expression of Multidrug Resistance Proteins of Intestinal Barrier. J Xenobiot 2023; 13:172-192. [PMID: 37092502 PMCID: PMC10123636 DOI: 10.3390/jox13020014] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/13/2023] [Accepted: 03/21/2023] [Indexed: 03/29/2023] Open
Abstract
The role of intestinal barrier homeostasis in an individual’s general well-being has been widely addressed by the scientific community. Colorectal cancer is among the illnesses that most affect this biological barrier. While chemotherapy is the first choice to treat this type of cancer, multidrug resistance (MDR) is the major setback against the commonly used drugs, with the ATP-binding cassette transporters (ABC transporters) being the major players. The role of P-glycoprotein (P-gp), multidrug resistance protein 1 (MRP1), or breast cancer resistance protein (ABCG2) in the efflux of chemotherapeutic drugs is well described in cancer cells, highlighting these proteins as interesting druggable targets to reverse MDR, decrease drug dosage, and consequently undesired toxicity. Natural products, especially phytochemicals, have a wide diversity of chemical structures, and some particular classes, such as phenolic acids, flavonoids, or pentacyclic triterpenoids, have been reported as inhibitors of P-gp, MRP1, and ABCG2, being able to sensitize cancer cells to chemotherapy drugs. Nevertheless, ABC transporters play a vital role in the cell’s defense against xenobiotics, and some phytochemicals have also been shown to induce the transporters’ activity. A balance must be obtained between xenobiotic efflux in non-tumor cells and bioaccumulation of chemotherapy drugs in cancer cells, in which ABC transporters are essential and natural products play a pivotal role that must be further analyzed. This review summarizes the knowledge concerning the nomenclature and function of ABC-transporters, emphasizing their role in the intestinal barrier cells. In addition, it also focuses on the role of natural products commonly found in food products, e.g., phytochemicals, as modulators of ABC-transporter activity and expression, which are promising nutraceutical molecules to formulate new drug combinations to overcome multidrug resistance.
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13
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Liu J, Wang X, Jin K, Liu Y, Li J, Du G, Lv X, Liu L. In Silico Prediction and Mining of Exporters for Secretory Bioproduction of Terpenoids in Saccharomyces cerevisiae. ACS Synth Biol 2023; 12:863-876. [PMID: 36867848 DOI: 10.1021/acssynbio.2c00673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
Abstract
Terpenoids are the largest class of natural products, and their bioproduction by engineered cell factories receives high attention. However, excessive intracellular accumulation is one of the bottlenecks that limit the further improvement of the yield of terpenoid products. Therefore, it is important to mine exporters to achieve the secretory production of terpenoids. This study proposed a framework for the in silico prediction and mining of terpenoid exporters in Saccharomyces cerevisiae. Through the process of "mining-docking-construction-validation", we found that Pdr5 of ATP-binding cassette (ABC) transporters and Osh3 of oxysterol-binding homology (Osh) proteins can promote squalene efflux. Squalene secretion of the strain overexpressing Pdr5 and Osh3 increased to 141.1 times that of the control strain. Besides squalene, ABC exporters also can promote the secretion of β-carotene and retinal. Molecular dynamics simulation results revealed that before exporter conformations transitioned to the "outward-open" states, the substrates might have bound to the tunnels and prepared for rapid efflux. Overall, this study provides a terpenoid exporter prediction and mining framework that may be generally used to identify exporters of other terpenoids.
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Affiliation(s)
- Jiaheng Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China.,Science Center for Future Foods, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Xinglong Wang
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China.,Science Center for Future Foods, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Ke Jin
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China.,Science Center for Future Foods, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Yanfeng Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China.,Science Center for Future Foods, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Jianghua Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China.,Science Center for Future Foods, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Guocheng Du
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China.,Science Center for Future Foods, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Xueqin Lv
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China.,Science Center for Future Foods, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Long Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China.,Science Center for Future Foods, Ministry of Education, Jiangnan University, Wuxi 214122, China
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14
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Plummer-Medeiros AM, Culbertson AT, Morales-Perez CL, Liao M. Activity and Structural Dynamics of Human ABCA1 in a Lipid Membrane. J Mol Biol 2023; 435:168038. [PMID: 36889459 DOI: 10.1016/j.jmb.2023.168038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 02/23/2023] [Accepted: 02/24/2023] [Indexed: 03/08/2023]
Abstract
The human ATP-binding cassette (ABC) transporter ABCA1 plays a critical role in lipid homeostasis as it extracts sterols and phospholipids from the plasma membrane for excretion to the extracellular apolipoprotein A-I and subsequent formation of high-density lipoprotein (HDL) particles. Deleterious mutations of ABCA1 lead to sterol accumulation and are associated with atherosclerosis, poor cardiovascular outcomes, cancer, and Alzheimer's disease. The mechanism by which ABCA1 drives lipid movement is poorly understood, and a unified platform to produce active ABCA1 protein for both functional and structural studies has been missing. In this work, we established a stable expression system for both a human cell-based sterol export assay and protein purification for in vitro biochemical and structural studies. ABCA1 produced in this system was active in sterol export and displayed enhanced ATPase activity after reconstitution into a lipid bilayer. Our single-particle cryo-EM study of ABCA1 in nanodiscs showed protein induced membrane curvature, revealed multiple distinct conformations, and generated a structure of nanodisc-embedded ABCA1 at 4.0-Å resolution representing a previously unknown conformation. Comparison of different ABCA1 structures and molecular dynamics simulations demonstrates both concerted domain movements and conformational variations within each domain. Taken together, our platform for producing and characterizing ABCA1 in a lipid membrane enabled us to gain important mechanistic and structural insights and paves the way for investigating modulators that target the functions of ABCA1.
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Affiliation(s)
- Ashlee M Plummer-Medeiros
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA; Bryn Mawr College Chemistry Department, 101 N Merion Avenue, Bryn Mawr, PA 19010, USA
| | - Alan T Culbertson
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA; Roivant Sciences, Inc., 451 D Street, Boston, MA 02210, USA
| | - Claudio L Morales-Perez
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA; Generate Biomedicines, 4 Corporate Drive Andover, MA, 01810, USA
| | - Maofu Liao
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA; Department of Chemical Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China.
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15
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Tóth Á, Janaszkiewicz A, Crespi V, Di Meo F. On the interplay between lipids and asymmetric dynamics of an NBS degenerate ABC transporter. Commun Biol 2023; 6:149. [PMID: 36737455 PMCID: PMC9898250 DOI: 10.1038/s42003-023-04537-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 01/25/2023] [Indexed: 02/05/2023] Open
Abstract
Multidrug resistance-associated proteins are ABC C-family exporters. They are crucial in pharmacology as they transport various substrates across membranes. However, the role of the degenerate nucleotide-binding site (NBS) remains unclear likewise the interplay with the surrounding lipid environment. Here, we propose a dynamic and structural overview of MRP1 from ca. 110 μs molecular dynamics simulations. ATP binding to NBS1 is likely maintained along several transport cycles. Asymmetric NBD behaviour is ensured by lower signal transduction from NBD1 to the rest of the protein owing to the absence of ball-and-socket conformation between NBD1 and coupling helices. Even though surrounding lipids play an active role in the allosteric communication between the substrate-binding pocket and NBDs, our results suggest that lipid composition has a limited impact, mostly by affecting transport kinetics. We believe that our work can be extended to other degenerate NBS ABC proteins and provide hints for deciphering mechanistic differences among ABC transporters.
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Affiliation(s)
- Ágota Tóth
- grid.9966.00000 0001 2165 4861Inserm U1248 Pharmacology & Transplantation, ΩHealth Institute—Univ. Limoges, 2 rue du Prof. Descottes, 87000 F Limoges, France
| | - Angelika Janaszkiewicz
- grid.9966.00000 0001 2165 4861Inserm U1248 Pharmacology & Transplantation, ΩHealth Institute—Univ. Limoges, 2 rue du Prof. Descottes, 87000 F Limoges, France
| | - Veronica Crespi
- grid.9966.00000 0001 2165 4861Inserm U1248 Pharmacology & Transplantation, ΩHealth Institute—Univ. Limoges, 2 rue du Prof. Descottes, 87000 F Limoges, France
| | - Florent Di Meo
- Inserm U1248 Pharmacology & Transplantation, ΩHealth Institute-Univ. Limoges, 2 rue du Prof. Descottes, 87000 F, Limoges, France.
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16
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Velilla JA, Kenney GE, Gaudet R. Structure and function of prodrug-activating peptidases. Biochimie 2023; 205:124-135. [PMID: 36803695 PMCID: PMC10030199 DOI: 10.1016/j.biochi.2022.07.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 07/25/2022] [Indexed: 11/11/2022]
Abstract
Bacteria protect themselves from the toxicity of antimicrobial metabolites they produce through several strategies. In one resistance mechanism, bacteria assemble a non-toxic precursor on an N-acyl-d-asparagine prodrug motif in the cytoplasm, then export it to the periplasm where a dedicated d-amino peptidase hydrolyzes the prodrug motif. These prodrug-activating peptidases contain an N-terminal periplasmic S12 hydrolase domain and C-terminal transmembrane domains (TMDs) of varying lengths: type I peptidases contain three transmembrane helices, and type II peptidases have an additional C-terminal ABC half-transporter. We review studies which have addressed the role of the TMD in function, the substrate specificity, and the biological assembly of ClbP, the type I peptidase that activates colibactin. We use modeling and sequence analyses to extend those insights to other prodrug-activating peptidases and ClbP-like proteins which are not part of prodrug resistance gene clusters. These ClbP-like proteins may play roles in the biosynthesis or degradation of other natural products, including antibiotics, may adopt different TMD folds, and have different substrate specificity compared to prodrug-activating homologs. Finally, we review the data supporting the long-standing hypothesis that ClbP interacts with transporters in the cell and that this association is important for the export of other natural products. Future investigations of this hypothesis as well as of the structure and function of type II peptidases will provide a complete account of the role of prodrug-activating peptidases in the activation and secretion of bacterial toxins.
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Affiliation(s)
- José A Velilla
- Department of Molecular and Cellular Biology, Harvard University, 52 Oxford St, Cambridge, MA, 02138, USA
| | - Grace E Kenney
- Department of Chemistry and Chemical Biology, Harvard University, 38 Oxford St, Cambridge, MA, USA
| | - Rachelle Gaudet
- Department of Molecular and Cellular Biology, Harvard University, 52 Oxford St, Cambridge, MA, 02138, USA.
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17
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Alhumaidi M, Nentwig LM, Rahman H, Schmitt L, Rudrow A, Harris A, Dillon C, Restrepo L, Lamping E, Arya N, Ambudkar SV, Choy JS, Golin J. Residues forming the gating regions of asymmetric multidrug transporter Pdr5 also play roles in conformational switching and protein folding. J Biol Chem 2022; 298:102689. [PMID: 36370844 PMCID: PMC9723933 DOI: 10.1016/j.jbc.2022.102689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Revised: 10/31/2022] [Accepted: 11/06/2022] [Indexed: 11/11/2022] Open
Abstract
ATP-binding cassette (ABC) multidrug transporters are large, polytopic membrane proteins that exhibit astonishing promiscuity for their transport substrates. These transporters unidirectionally efflux thousands of structurally and functionally distinct compounds. To preclude the reentry of xenobiotic molecules via the drug-binding pocket, these proteins contain a highly conserved molecular gate, essentially allowing the transporters to function as molecular diodes. However, the structure-function relationship of these conserved gates and gating regions are not well characterized. In this study, we combine recent single-molecule, cryo-EM data with genetic and biochemical analyses of residues in the gating region of the yeast multidrug transporter Pdr5, the founding member of a large group of clinically relevant asymmetric ABC efflux pumps. Unlike the symmetric ABCG2 efflux gate, the Pdr5 counterpart is highly asymmetric, with only four (instead of six) residues comprising the gate proper. However, other residues in the near vicinity are essential for the gating activity. Furthermore, we demonstrate that residues in the gate and in the gating regions have multiple functions. For example, we show that Ile-685 and Val-1372 are required not only for successful efflux but also for allosteric inhibition of Pdr5 ATPase activity. Our investigations reveal that the gating region residues of Pdr5, and possibly other ABCG transporters, play a role not only in molecular gating but also in allosteric regulation, conformational switching, and protein folding.
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Affiliation(s)
- Maryam Alhumaidi
- The Department of Biology, The Catholic University of America, Washington, USA
| | - Lea-Marie Nentwig
- The Department of Biology, The Catholic University of America, Washington, USA; Institute of Biochemistry, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Hadiar Rahman
- The Department of Biology, The Catholic University of America, Washington, USA
| | - Lutz Schmitt
- Institute of Biochemistry, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Andrew Rudrow
- The Department of Biology, The Catholic University of America, Washington, USA
| | - Andrzej Harris
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Cierra Dillon
- The Department of Biology, The Catholic University of America, Washington, USA
| | - Lucas Restrepo
- The Department of Biology, The Catholic University of America, Washington, USA
| | - Erwin Lamping
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Ontago, Dunedin, New Zealand
| | - Nidhi Arya
- The Department of Biology, The Catholic University of America, Washington, USA
| | - Suresh V Ambudkar
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
| | - John S Choy
- The Department of Biology, The Catholic University of America, Washington, USA
| | - John Golin
- The Department of Biology, The Catholic University of America, Washington, USA.
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18
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Tordai H, Suhajda E, Sillitoe I, Nair S, Varadi M, Hegedus T. Comprehensive Collection and Prediction of ABC Transmembrane Protein Structures in the AI Era of Structural Biology. Int J Mol Sci 2022; 23:ijms23168877. [PMID: 36012140 PMCID: PMC9408558 DOI: 10.3390/ijms23168877] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 08/05/2022] [Accepted: 08/07/2022] [Indexed: 02/06/2023] Open
Abstract
The number of unique transmembrane (TM) protein structures doubled in the last four years, which can be attributed to the revolution of cryo-electron microscopy. In addition, AlphaFold2 (AF2) also provided a large number of predicted structures with high quality. However, if a specific protein family is the subject of a study, collecting the structures of the family members is highly challenging in spite of existing general and protein domain-specific databases. Here, we demonstrate this and assess the applicability and usability of automatic collection and presentation of protein structures via the ABC protein superfamily. Our pipeline identifies and classifies transmembrane ABC protein structures using the PFAM search and also aims to determine their conformational states based on special geometric measures, conftors. Since the AlphaFold database contains structure predictions only for single polypeptide chains, we performed AF2-Multimer predictions for human ABC half transporters functioning as dimers. Our AF2 predictions warn of possibly ambiguous interpretation of some biochemical data regarding interaction partners and call for further experiments and experimental structure determination. We made our predicted ABC protein structures available through a web application, and we joined the 3D-Beacons Network to reach the broader scientific community through platforms such as PDBe-KB.
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Affiliation(s)
- Hedvig Tordai
- Department of Biophysics and Radiation Biology, Semmelweis University, 1085 Budapest, Hungary
| | - Erzsebet Suhajda
- Department of Biophysics and Radiation Biology, Semmelweis University, 1085 Budapest, Hungary
- Faculty of Electrical Engineering and Informatics, Budapest University of Technology and Economics, 1111 Budapest, Hungary
- Wigner Research Centre for Physics, 1121 Budapest, Hungary
| | - Ian Sillitoe
- Department of Structural and Molecular Biology, University College London, London WC1E 6BT, UK
| | - Sreenath Nair
- European Bioinformatics Institute, European Molecular Biology Laboratory, Hinxton CB10 1SD, UK
| | - Mihaly Varadi
- European Bioinformatics Institute, European Molecular Biology Laboratory, Hinxton CB10 1SD, UK
| | - Tamas Hegedus
- Department of Biophysics and Radiation Biology, Semmelweis University, 1085 Budapest, Hungary
- ELKH-SE Biophysical Virology Research Group, Eötvös Loránd Research Network, 1052 Budapest, Hungary
- Correspondence:
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19
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Kawaguchi K, Imanaka T. Substrate Specificity and the Direction of Transport in the ABC Transporters ABCD1–3 and ABCD4. Chem Pharm Bull (Tokyo) 2022; 70:533-539. [DOI: 10.1248/cpb.c21-01021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Kosuke Kawaguchi
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama
| | - Tsuneo Imanaka
- Faculty of Pharmaceutical Sciences, Hiroshima International University
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20
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Structural basis for heme detoxification by an ATP-binding cassette-type efflux pump in gram-positive pathogenic bacteria. Proc Natl Acad Sci U S A 2022; 119:e2123385119. [PMID: 35767641 PMCID: PMC9271180 DOI: 10.1073/pnas.2123385119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Bacterial pathogens acquire heme from the host hemoglobin as an iron nutrient for their virulence and proliferation in blood. Concurrently, they encounter cytotoxic-free heme that escapes the heme-acquisition process. To overcome this toxicity, many gram-positive bacteria employ an ATP-binding cassette heme-dedicated efflux pump, HrtBA in the cytoplasmic membranes. Although genetic analyses have suggested that HrtBA expels heme from the bacterial membranes, the molecular mechanism of heme efflux remains elusive due to the lack of protein studies. Here, we show the biochemical properties and crystal structures of Corynebacterium diphtheriae HrtBA, alone and in complex with heme or an ATP analog, and we reveal how HrtBA extracts heme from the membrane and releases it. HrtBA consists of two cytoplasmic HrtA ATPase subunits and two transmembrane HrtB permease subunits. A heme-binding site is formed in the HrtB dimer and is laterally accessible to heme in the outer leaflet of the membrane. The heme-binding site captures heme from the membrane using a glutamate residue of either subunit as an axial ligand and sequesters the heme within the rearranged transmembrane helix bundle. By ATP-driven HrtA dimerization, the heme-binding site is squeezed to extrude the bound heme. The mechanism sheds light on the detoxification of membrane-bound heme in this bacterium.
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21
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Ding D, Wu JX, Duan X, Ma S, Lai L, Chen L. Structural identification of vasodilator binding sites on the SUR2 subunit. Nat Commun 2022; 13:2675. [PMID: 35562524 PMCID: PMC9106677 DOI: 10.1038/s41467-022-30428-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 04/28/2022] [Indexed: 11/09/2022] Open
Abstract
ATP-sensitive potassium channels (KATP), composed of Kir6 and SUR subunits, convert the metabolic status of the cell into electrical signals. Pharmacological activation of SUR2- containing KATP channels by class of small molecule drugs known as KATP openers leads to hyperpolarization of excitable cells and to vasodilation. Thus, KATP openers could be used to treat cardiovascular diseases. However, where these vasodilators bind to KATP and how they activate the channel remains elusive. Here, we present cryo-EM structures of SUR2A and SUR2B subunits in complex with Mg-nucleotides and P1075 or levcromakalim, two chemically distinct KATP openers that are specific to SUR2. Both P1075 and levcromakalim bind to a common site in the transmembrane domain (TMD) of the SUR2 subunit, which is between TMD1 and TMD2 and is embraced by TM10, TM11, TM12, TM14, and TM17. These KATP openers synergize with Mg-nucleotides to stabilize SUR2 in the NBD-dimerized occluded state to activate the channel.
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Affiliation(s)
- Dian Ding
- State Key Laboratory of Membrane Biology, College of Future Technology, Institute of Molecular Medicine, Peking University, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, 100871, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Peking University, 100871, Beijing, China.,Academy for Advanced Interdisciplinary Studies, Peking University, 100871, Beijing, China.,National Biomedical Imaging Center, Peking University, 100871, Beijing, China
| | - Jing-Xiang Wu
- State Key Laboratory of Membrane Biology, College of Future Technology, Institute of Molecular Medicine, Peking University, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, 100871, Beijing, China.,National Biomedical Imaging Center, Peking University, 100871, Beijing, China
| | - Xinli Duan
- Beijing Jingtai Technology Co., Ltd., Beijing, China
| | - Songling Ma
- Beijing Jingtai Technology Co., Ltd., Beijing, China
| | - Lipeng Lai
- Beijing Jingtai Technology Co., Ltd., Beijing, China
| | - Lei Chen
- State Key Laboratory of Membrane Biology, College of Future Technology, Institute of Molecular Medicine, Peking University, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, 100871, Beijing, China. .,Peking-Tsinghua Center for Life Sciences, Peking University, 100871, Beijing, China. .,Academy for Advanced Interdisciplinary Studies, Peking University, 100871, Beijing, China. .,National Biomedical Imaging Center, Peking University, 100871, Beijing, China.
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22
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Pei J, Cong Q. Evolutionary origin and sequence signatures of the heterodimeric
ABCG5
/
ABCG8
transporter. Protein Sci 2022; 31:e4297. [PMID: 35481657 PMCID: PMC8994503 DOI: 10.1002/pro.4297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 03/01/2022] [Accepted: 03/04/2022] [Indexed: 11/08/2022]
Abstract
ATP-binding cassette (ABC) systems, characterized by ABC-type nucleotide-binding domains (NBDs), play crucial roles in various aspects of human physiology. Human ABCG5 and ABCG8 form a heterodimeric transporter that functions in the efflux of sterols. We used sequence similarity search, multiple sequence alignment, phylogenetic analysis, and structure comparison to study the evolutionary origin and sequence signatures of ABCG5 and ABCG8. Orthologs of ABCG5 and ABCG8, supported by phylogenetic analysis and signature residues, were identified in bilaterian animals, Filasterea, Fungi, and Amoebozoa. Such a phylogenetic distribution suggests that ABCG5 and ABCG8 could have originated in the last common ancestor of Amorphea (the unikonts), the eukaryotic group including Amoebozoa and Opisthokonta. ABCG5 and ABCG8 were missing in genomes of various lineages such as snakes, jawless vertebrates, non-vertebrate chordates, echinoderms, and basal metazoan groups. Amino-acid changes in key positions in ABCG8 Walker A motif and/or ABCG5 C-loop were observed in most tetrapod organisms, likely resulted in the loss of ATPase activity at one nucleotide-binding site. ABCG5 and ABCG8 in Ecdysozoa (such as insects) exhibit elevated evolutionary rates and accumulate various changes in their NBD functional motifs. Alignment inspection revealed several residue positions that show different amino-acid usages in ABCG5/ABCG8 compared to other ABCG subfamily proteins. These residues were mapped to the structural cores of transmembrane domains (TMDs), the NBD-TMD interface, and the interface between TMDs. They serve as sequence signatures to differentiate ABCG5/ABCG8 from other ABCG subfamily proteins, and some of them may contribute to substrate specificity of the ABCG5/ABCG8 transporter.
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Affiliation(s)
- Jimin Pei
- Eugene McDermott Center for Human Growth and Development University of Texas Southwestern Medical Center Dallas Texas USA
- Department of Biophysics University of Texas Southwestern Medical Center Dallas Texas USA
| | - Qian Cong
- Eugene McDermott Center for Human Growth and Development University of Texas Southwestern Medical Center Dallas Texas USA
- Department of Biophysics University of Texas Southwestern Medical Center Dallas Texas USA
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23
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Pan D, Oyama R, Sato T, Nakane T, Mizunuma R, Matsuoka K, Joti Y, Tono K, Nango E, Iwata S, Nakatsu T, Kato H. Crystal structure of CmABCB1 multi-drug exporter in lipidic mesophase revealed by LCP-SFX. IUCRJ 2022; 9:134-145. [PMID: 35059217 PMCID: PMC8733880 DOI: 10.1107/s2052252521011611] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 11/03/2021] [Indexed: 06/14/2023]
Abstract
CmABCB1 is a Cyanidioschyzon merolae homolog of human ABCB1, a well known ATP-binding cassette (ABC) transporter responsible for multi-drug resistance in various cancers. Three-dimensional structures of ABCB1 homologs have revealed the snapshots of inward- and outward-facing states of the transporters in action. However, sufficient information to establish the sequential movements of the open-close cycles of the alternating-access model is still lacking. Serial femtosecond crystallography (SFX) using X-ray free-electron lasers has proven its worth in determining novel structures and recording sequential conformational changes of proteins at room temperature, especially for medically important membrane proteins, but it has never been applied to ABC transporters. In this study, 7.7 mono-acyl-glycerol with cholesterol as the host lipid was used and obtained well diffracting microcrystals of the 130 kDa CmABCB1 dimer. Successful SFX experiments were performed by adjusting the viscosity of the crystal suspension of the sponge phase with hy-droxy-propyl methyl-cellulose and using the high-viscosity sample injector for data collection at the SACLA beamline. An outward-facing structure of CmABCB1 at a maximum resolution of 2.22 Å is reported, determined by SFX experiments with crystals formed in the lipidic cubic phase (LCP-SFX), which has never been applied to ABC transporters. In the type I crystal, CmABCB1 dimers interact with adjacent molecules via not only the nucleotide-binding domains but also the transmembrane domains (TMDs); such an interaction was not observed in the previous type II crystal. Although most parts of the structure are similar to those in the previous type II structure, the substrate-exit region of the TMD adopts a different configuration in the type I structure. This difference between the two types of structures reflects the flexibility of the substrate-exit region of CmABCB1, which might be essential for the smooth release of various substrates from the transporter.
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Affiliation(s)
- Dongqing Pan
- Department of Structural Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Ryo Oyama
- Department of Structural Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Tomomi Sato
- Department of Structural Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Takanori Nakane
- Department of Biological Science, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ryo Mizunuma
- Department of Structural Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Keita Matsuoka
- Department of Structural Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yasumasa Joti
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Kensuke Tono
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Eriko Nango
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - So Iwata
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Yoshidakonoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Toru Nakatsu
- Department of Structural Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Hiroaki Kato
- Department of Structural Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
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24
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Infield DT, Strickland KM, Gaggar A, McCarty NA. The molecular evolution of function in the CFTR chloride channel. J Gen Physiol 2021; 153:212705. [PMID: 34647973 PMCID: PMC8640958 DOI: 10.1085/jgp.202012625] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 08/11/2021] [Accepted: 09/09/2021] [Indexed: 12/13/2022] Open
Abstract
The ATP-binding cassette (ABC) transporter superfamily includes many proteins of clinical relevance, with genes expressed in all domains of life. Although most members use the energy of ATP binding and hydrolysis to accomplish the active import or export of various substrates across membranes, the cystic fibrosis transmembrane conductance regulator (CFTR) is the only known animal ABC transporter that functions primarily as an ion channel. Defects in CFTR, which is closely related to ABCC subfamily members that bear function as bona fide transporters, underlie the lethal genetic disease cystic fibrosis. This article seeks to integrate structural, functional, and genomic data to begin to answer the critical question of how the function of CFTR evolved to exhibit regulated channel activity. We highlight several examples wherein preexisting features in ABCC transporters were functionally leveraged as is, or altered by molecular evolution, to ultimately support channel function. This includes features that may underlie (1) construction of an anionic channel pore from an anionic substrate transport pathway, (2) establishment and tuning of phosphoregulation, and (3) optimization of channel function by specialized ligand–channel interactions. We also discuss how divergence and conservation may help elucidate the pharmacology of important CFTR modulators.
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Affiliation(s)
- Daniel T Infield
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA
| | | | - Amit Gaggar
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL.,Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, AL.,Program in Protease and Matrix Biology, University of Alabama at Birmingham, Birmingham, AL.,Birmingham Veterans Administration Medical Center, Birmingham, AL
| | - Nael A McCarty
- Department of Pediatrics, Emory University, Atlanta, GA.,Children's Healthcare of Atlanta Center for Cystic Fibrosis and Airways Disease Research, Emory University, Atlanta, GA
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25
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Thélot FA, Zhang W, Song K, Xu C, Huang J, Liao M. Distinct allosteric mechanisms of first-generation MsbA inhibitors. Science 2021; 374:580-585. [PMID: 34554829 DOI: 10.1126/science.abi9009] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- François A Thélot
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.,Biological and Biomedical Sciences Program, Harvard University, Cambridge, MA, USA
| | - Wenyi Zhang
- Key Laboratory of Structural Biology of Zhejiang Province, Westlake University, Hangzhou, China.,Westlake AI Therapeutics Lab, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, China
| | - KangKang Song
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, USA.,Cryo-EM Core Facility, University of Massachusetts Medical School, Worcester, MA, USA
| | - Chen Xu
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, USA.,Cryo-EM Core Facility, University of Massachusetts Medical School, Worcester, MA, USA
| | - Jing Huang
- Key Laboratory of Structural Biology of Zhejiang Province, Westlake University, Hangzhou, China.,Westlake AI Therapeutics Lab, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, China
| | - Maofu Liao
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
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26
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Noack S, Harrington J, Carithers DS, Kaminsky R, Selzer PM. Heartworm disease - Overview, intervention, and industry perspective. Int J Parasitol Drugs Drug Resist 2021; 16:65-89. [PMID: 34030109 PMCID: PMC8163879 DOI: 10.1016/j.ijpddr.2021.03.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 03/26/2021] [Accepted: 03/30/2021] [Indexed: 02/06/2023]
Abstract
Dirofilaria immitis, also known as heartworm, is a major parasitic threat for dogs and cats around the world. Because of its impact on the health and welfare of companion animals, heartworm disease is of huge veterinary and economic importance especially in North America, Europe, Asia and Australia. Within the animal health market many different heartworm preventive products are available, all of which contain active components of the same drug class, the macrocyclic lactones. In addition to compliance issues, such as under-dosing or irregular treatment intervals, the occurrence of drug-resistant heartworms within the populations in the Mississippi River areas adds to the failure of preventive treatments. The objective of this review is to provide an overview of the disease, summarize the current disease control measures and highlight potential new avenues and best practices for treatment and prevention.
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Affiliation(s)
- Sandra Noack
- Boehringer Ingelheim Animal Health, Binger Str. 173, 55216, Ingelheim am Rhein, Germany
| | - John Harrington
- Boehringer Ingelheim Animal Health, 1730 Olympic Drive, 30601, Athens, GA, USA
| | - Douglas S Carithers
- Boehringer Ingelheim Animal Health, 3239 Satellite Blvd, 30096, Duluth, GA, USA
| | - Ronald Kaminsky
- paraC Consulting, Altenstein 13, 79685, Häg-Ehrsberg, Germany
| | - Paul M Selzer
- Boehringer Ingelheim Animal Health, Binger Str. 173, 55216, Ingelheim am Rhein, Germany.
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27
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He G, Tian W, Qin L, Meng L, Wu D, Huang Y, Li D, Zhao D, He T. Identification of novel heavy metal detoxification proteins in Solanum tuberosum: Insights to improve food security protection from metal ion stress. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 779:146197. [PMID: 33744586 DOI: 10.1016/j.scitotenv.2021.146197] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/07/2021] [Accepted: 02/25/2021] [Indexed: 05/22/2023]
Abstract
With increasingly serious environmental pollution problems, research has focused on identifying functional genes within plants that can help ensure food security and soil governance. In particular, plants seem to have been able to evolve specific functional genes to respond to environmental changes by losing partial gene functions, thereby representing a novel adaptation mechanism. Herein, a new category of functional genes was identified and investigated, providing new directions for understanding heavy metal detoxification mechanisms. Interestingly, this category of proteins appears to exhibit specific complexing functions for heavy metals. Further, a new approach was established to evaluate ATP-binding cassette (ABC) transporter family functions using microRNA targeted inhibition. Moreover, mutant and functional genes were identified for future research targets. Expression profiling under five heavy metal stress treatments provided an important framework to further study defense responses of plants to metal exposure. In conclusion, the new insights identified here provide a theoretical basis and reference to better understand the mechanisms of heavy metal tolerance in potato plants. Further, these new data provide additional directions and foundations for mining gene resources for heavy metal tolerance genes to improve safe, green crop production and plant treatment of heavy metal soil pollution.
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Affiliation(s)
- Guandi He
- The Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Institute of Agro-Bioengineering and College of Life Sciences, Guizhou University, Guiyang 550025, China.
| | - Weijun Tian
- Agricultural College, Guizhou University, Guiyang 550025, China.
| | - Lijun Qin
- The Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Institute of Agro-Bioengineering and College of Life Sciences, Guizhou University, Guiyang 550025, China.
| | - Lulu Meng
- Agricultural College, Guizhou University, Guiyang 550025, China.
| | - Danxia Wu
- Agricultural College, Guizhou University, Guiyang 550025, China.
| | - Yun Huang
- Agricultural College, Guizhou University, Guiyang 550025, China.
| | - Dandan Li
- Agricultural College, Guizhou University, Guiyang 550025, China.
| | - Degang Zhao
- The Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Institute of Agro-Bioengineering and College of Life Sciences, Guizhou University, Guiyang 550025, China; Guizhou Academy of Agricultural Science, Guiyang 550025, China.
| | - Tengbing He
- Agricultural College, Guizhou University, Guiyang 550025, China; Institute of New Rural Development of Guizhou University, Guiyang 550025, China.
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28
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Cho CH, Jang S, Choi BY, Hong D, Choi DS, Choi S, Kim H, Han SK, Kim S, Kim M, Palmgren M, Sohn KH, Yoon HS, Lee Y. Phylogenetic analysis of ABCG subfamily proteins in plants: functional clustering and coevolution with ABCGs of pathogens. PHYSIOLOGIA PLANTARUM 2021; 172:1422-1438. [PMID: 31828796 PMCID: PMC8359288 DOI: 10.1111/ppl.13052] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 11/19/2019] [Indexed: 05/02/2023]
Abstract
ABCG subfamily proteins are highly enriched in terrestrial plants. Many of these proteins secrete secondary metabolites that repel or inhibit pathogens. To establish why the ABCG subfamily proteins proliferated extensively during evolution, we constructed phylogenetic trees from a broad range of eukaryotic organisms. ABCG proteins were massively duplicated in land plants and in oomycetes, a group of agronomically important plant pathogens, which prompted us to hypothesize that plant and pathogen ABCGs coevolved. Supporting this hypothesis, full-size ABCGs in host plants (Arabidopsis thaliana and Glycine max) and their pathogens (Hyaloperonospora arabidopsidis and Phytophthora sojae, respectively) had similar divergence times and patterns. Furthermore, generalist pathogens with broad ranges of host plants have diversified more ABCGs than their specialist counterparts. The hypothesis was further tested using an example pair of ABCGs that first diverged during multiplication in a host plant and its pathogen: AtABCG31 of A. thaliana and HpaP802307 of H. arabidopsidis. AtABCG31 expression was activated following infection with H. arabidopsidis, and disrupting AtABCG31 led to increased susceptibility to H. arabidopsidis. Together, our results suggest that ABCG genes in plants and their oomycete pathogens coevolved in an arms race, to extrude secondary metabolites involved in the plant's defense response against pathogens.
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Affiliation(s)
- Chung Hyun Cho
- Department of Biological SciencesSungkyunkwan UniversitySuwonKorea
| | - Sunghoon Jang
- Department of Life SciencePohang University of Science and Technology (POSTECH)Pohang37673Korea
| | - Bae Young Choi
- Division of Integrative Bioscience and BiotechnologyPOSTECHPohang37673Korea
| | - Daewoong Hong
- Department of Life SciencePohang University of Science and Technology (POSTECH)Pohang37673Korea
| | - Du Seok Choi
- Department of Life SciencePohang University of Science and Technology (POSTECH)Pohang37673Korea
- Present address:
GreenBio Center, Corporate R&D, LG Chem, LtdSeoul07796Korea
| | - Sera Choi
- Department of Life SciencePohang University of Science and Technology (POSTECH)Pohang37673Korea
| | - Haseong Kim
- Department of Life SciencePohang University of Science and Technology (POSTECH)Pohang37673Korea
| | - Seong Kyu Han
- Department of Life SciencePohang University of Science and Technology (POSTECH)Pohang37673Korea
| | - Sanguk Kim
- Division of Integrative Bioscience and BiotechnologyPOSTECHPohang37673Korea
| | - Min‐Sung Kim
- Division of Integrative Bioscience and BiotechnologyPOSTECHPohang37673Korea
| | - Michael Palmgren
- Department of Plant and Environmental ScienceUniversity of CopenhagenDK‐1871FrederiksbergDenmark
| | - Kee Hoon Sohn
- Department of Life SciencePohang University of Science and Technology (POSTECH)Pohang37673Korea
- Division of Integrative Bioscience and BiotechnologyPOSTECHPohang37673Korea
| | - Hwan Su Yoon
- Department of Biological SciencesSungkyunkwan UniversitySuwonKorea
| | - Youngsook Lee
- Department of Life SciencePohang University of Science and Technology (POSTECH)Pohang37673Korea
- Division of Integrative Bioscience and BiotechnologyPOSTECHPohang37673Korea
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29
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Ben Saad A, Vauthier V, Tóth Á, Janaszkiewicz A, Durand-Schneider AM, Bruneau A, Delaunay JL, Lapalus M, Mareux E, Garcin I, Gonzales E, Housset C, Aït-Slimane T, Jacquemin E, Di Meo F, Falguières T. Effect of CFTR correctors on the traffic and the function of intracellularly retained ABCB4 variants. Liver Int 2021; 41:1344-1357. [PMID: 33650203 DOI: 10.1111/liv.14839] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 01/25/2021] [Accepted: 02/23/2021] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIM ABCB4 is expressed at the canalicular membrane of hepatocytes. This ATP-binding cassette (ABC) transporter is responsible for the secretion of phosphatidylcholine into bile canaliculi. Missense genetic variations of ABCB4 are correlated with several rare cholestatic liver diseases, the most severe being progressive familial intrahepatic cholestasis type 3 (PFIC3). In a repurposing strategy to correct intracellularly retained ABCB4 variants, we tested 16 compounds previously validated as cystic fibrosis transmembrane conductance regulator (CFTR) correctors. METHODS The maturation, intracellular localization and activity of intracellularly retained ABCB4 variants were analyzed in cell models after treatment with CFTR correctors. In addition, in silico molecular docking calculations were performed to test the potential interaction of CFTR correctors with ABCB4. RESULTS We observed that the correctors C10, C13, and C17, as well as the combinations of C3 + C18 and C4 + C18, allowed the rescue of maturation and canalicular localization of four distinct traffic-defective ABCB4 variants. However, such treatments did not permit a rescue of the phosphatidylcholine secretion activity of these defective variants and were also inhibitory of the activity of wild type ABCB4. In silico molecular docking analyses suggest that these CFTR correctors might directly interact with transmembrane domains and/or ATP-binding sites of the transporter. CONCLUSION Our results illustrate the uncoupling between the traffic and the activity of ABCB4 because the same molecules can rescue the traffic of defective variants while they inhibit the secretion activity of the transporter. We expect that this study will help to design new pharmacological tools with potential clinical interest.
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Affiliation(s)
- Amel Ben Saad
- Inserm, Université Paris-Saclay, Physiopathogénèse et traitement des maladies du foie, UMR_S 1193, Orsay, France.,Inserm, Sorbonne Université, Centre de Recherche Saint-Antoine (CRSA), UMR_S 938, Institute of Cardiometabolism and Nutrition (ICAN), Paris, France
| | - Virginie Vauthier
- Inserm, Sorbonne Université, Centre de Recherche Saint-Antoine (CRSA), UMR_S 938, Institute of Cardiometabolism and Nutrition (ICAN), Paris, France.,Université de Paris, Institut Cochin, Inserm U1016, CNRS UMR 8104, Paris, France
| | - Ágota Tóth
- Inserm, Université de Limoges, UMR 1248 IPPRITT, Limoges, France
| | | | - Anne-Marie Durand-Schneider
- Inserm, Sorbonne Université, Centre de Recherche Saint-Antoine (CRSA), UMR_S 938, Institute of Cardiometabolism and Nutrition (ICAN), Paris, France
| | - Alix Bruneau
- Inserm, Sorbonne Université, Centre de Recherche Saint-Antoine (CRSA), UMR_S 938, Institute of Cardiometabolism and Nutrition (ICAN), Paris, France.,Department of Hepatology & Gastroenterology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Jean-Louis Delaunay
- Inserm, Sorbonne Université, Centre de Recherche Saint-Antoine (CRSA), UMR_S 938, Institute of Cardiometabolism and Nutrition (ICAN), Paris, France
| | - Martine Lapalus
- Inserm, Université Paris-Saclay, Physiopathogénèse et traitement des maladies du foie, UMR_S 1193, Orsay, France
| | - Elodie Mareux
- Inserm, Université Paris-Saclay, Physiopathogénèse et traitement des maladies du foie, UMR_S 1193, Orsay, France
| | - Isabelle Garcin
- Inserm, Université Paris-Saclay, Physiopathogénèse et traitement des maladies du foie, UMR_S 1193, Orsay, France
| | - Emmanuel Gonzales
- Inserm, Université Paris-Saclay, Physiopathogénèse et traitement des maladies du foie, UMR_S 1193, Orsay, France.,Assistance Publique - Hôpitaux de Paris, CHU Bicêtre, Paediatric Hepatology & Paediatric Liver Transplant Department, Reference Center for Rare Paediatric Liver Diseases, FILFOIE, ERN Rare-Liver, Faculté de Médecine Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Chantal Housset
- Inserm, Sorbonne Université, Centre de Recherche Saint-Antoine (CRSA), UMR_S 938, Institute of Cardiometabolism and Nutrition (ICAN), Paris, France.,Assistance Publique - Hôpitaux de Paris, Hôpital Saint-Antoine, Reference Center for Inflammatory Biliary Diseases and Autoimmune Hepatitis, FILFOIE, ERN Rare-Liver, Paris, France
| | - Tounsia Aït-Slimane
- Inserm, Sorbonne Université, Centre de Recherche Saint-Antoine (CRSA), UMR_S 938, Institute of Cardiometabolism and Nutrition (ICAN), Paris, France
| | - Emmanuel Jacquemin
- Inserm, Université Paris-Saclay, Physiopathogénèse et traitement des maladies du foie, UMR_S 1193, Orsay, France.,Assistance Publique - Hôpitaux de Paris, CHU Bicêtre, Paediatric Hepatology & Paediatric Liver Transplant Department, Reference Center for Rare Paediatric Liver Diseases, FILFOIE, ERN Rare-Liver, Faculté de Médecine Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Florent Di Meo
- Inserm, Université de Limoges, UMR 1248 IPPRITT, Limoges, France
| | - Thomas Falguières
- Inserm, Université Paris-Saclay, Physiopathogénèse et traitement des maladies du foie, UMR_S 1193, Orsay, France
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30
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Abstract
ATP-binding cassette (ABC) transporters constitute one of the largest and most ancient protein superfamilies found in all living organisms. They function as molecular machines by coupling ATP binding, hydrolysis, and phosphate release to translocation of diverse substrates across membranes. The substrates range from vitamins, steroids, lipids, and ions to peptides, proteins, polysaccharides, and xenobiotics. ABC transporters undergo substantial conformational changes during substrate translocation. A comprehensive understanding of their inner workings thus requires linking these structural rearrangements to the different functional state transitions. Recent advances in single-particle cryogenic electron microscopy have not only delivered crucial information on the architecture of several medically relevant ABC transporters and their supramolecular assemblies, including the ATP-sensitive potassium channel and the peptide-loading complex, but also made it possible to explore the entire conformational space of these nanomachines under turnover conditions and thereby gain detailed mechanistic insights into their mode of action.
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Affiliation(s)
- Christoph Thomas
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany; ,
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany; ,
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31
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Stefan E, Obexer R, Hofmann S, Vu Huu K, Huang Y, Morgner N, Suga H, Tampé R. De novo macrocyclic peptides dissect energy coupling of a heterodimeric ABC transporter by multimode allosteric inhibition. eLife 2021; 10:67732. [PMID: 33929325 PMCID: PMC8116058 DOI: 10.7554/elife.67732] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 04/29/2021] [Indexed: 12/16/2022] Open
Abstract
ATP-binding cassette (ABC) transporters constitute the largest family of primary active transporters involved in a multitude of physiological processes and human diseases. Despite considerable efforts, it remains unclear how ABC transporters harness the chemical energy of ATP to drive substrate transport across cell membranes. Here, by random nonstandard peptide integrated discovery (RaPID), we leveraged combinatorial macrocyclic peptides that target a heterodimeric ABC transport complex and explore fundamental principles of the substrate translocation cycle. High-affinity peptidic macrocycles bind conformationally selective and display potent multimode inhibitory effects. The macrocycles block the transporter either before or after unidirectional substrate export along a single conformational switch induced by ATP binding. Our study reveals mechanistic principles of ATP binding, conformational switching, and energy transduction for substrate transport of ABC export systems. We highlight the potential of de novo macrocycles as effective inhibitors for membrane proteins implicated in multidrug resistance, providing avenues for the next generation of pharmaceuticals.
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Affiliation(s)
- Erich Stefan
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Frankfurt, Germany
| | - Richard Obexer
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Susanne Hofmann
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Frankfurt, Germany
| | - Khanh Vu Huu
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Frankfurt, Germany
| | - Yichao Huang
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Nina Morgner
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Frankfurt, Germany
| | - Hiroaki Suga
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Frankfurt, Germany
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32
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Structural Insights into Transporter-Mediated Drug Resistance in Infectious Diseases. J Mol Biol 2021; 433:167005. [PMID: 33891902 DOI: 10.1016/j.jmb.2021.167005] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 04/12/2021] [Accepted: 04/12/2021] [Indexed: 02/07/2023]
Abstract
Infectious diseases present a major threat to public health globally. Pathogens can acquire resistance to anti-infectious agents via several means including transporter-mediated efflux. Typically, multidrug transporters feature spacious, dynamic, and chemically malleable binding sites to aid in the recognition and transport of chemically diverse substrates across cell membranes. Here, we discuss recent structural investigations of multidrug transporters involved in resistance to infectious diseases that belong to the ATP-binding cassette (ABC) superfamily, the major facilitator superfamily (MFS), the drug/metabolite transporter (DMT) superfamily, the multidrug and toxic compound extrusion (MATE) family, the small multidrug resistance (SMR) family, and the resistance-nodulation-division (RND) superfamily. These structural insights provide invaluable information for understanding and combatting multidrug resistance.
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33
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Matsuoka K, Nakatsu T, Kato H. The crystal structure of the CmABCB1 G132V mutant, which favors the outward-facing state, reveals the mechanism of the pivotal joint between TM1 and TM3. Protein Sci 2021; 30:1064-1071. [PMID: 33683740 DOI: 10.1002/pro.4058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 02/27/2021] [Accepted: 03/02/2021] [Indexed: 01/12/2023]
Abstract
CmABCB1 is a homologue of human P-glycoprotein, which extrudes various substrates by iterative cycles of conformational changes between the inward- and outward-facing states. Comparison of the inward- and outward-facing structures of CmABCB1 suggested that pivotal joints in the transmembrane domain regulate the tilt of transmembrane helices. Transmembrane helix 1 (TM1) forms a tight helix-helix contact with TM3 at the TM1-3 joint. Mutation of Gly132 to valine at the TM1-3 joint, G132V, caused a 10-fold increase in ATPase activity, but the mechanism underlying this change remains unclear. Here, we report a crystal structure of the outward-facing state of the CmABCB1 G132V mutant at a 2.15 Å resolution. We observed structural displacements between the outward-facing states of G132V and the previous one at the region around the TM1-3 joint, and a significant expansion at the extracellular gate. We hypothesize that steric hindrance caused by the Val substitution shifted the conformational equilibrium toward the outward-facing state, favoring the dimeric state of the nucleotide-binding domains and thereby increasing the ATPase activity of the G132V mutant.
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Affiliation(s)
- Keita Matsuoka
- Department of Structural Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Toru Nakatsu
- Department of Structural Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan.,Advanced Photon Technology Division, RIKEN Harima Institute at SPring-8, Sayo-gun, Hyogo, Japan
| | - Hiroaki Kato
- Department of Structural Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan.,Advanced Photon Technology Division, RIKEN Harima Institute at SPring-8, Sayo-gun, Hyogo, Japan
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Shukla S, Baumgart T. Enzymatic trans-bilayer lipid transport: Mechanisms, efficiencies, slippage, and membrane curvature. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2021; 1863:183534. [PMID: 33340491 PMCID: PMC8351443 DOI: 10.1016/j.bbamem.2020.183534] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/03/2020] [Accepted: 12/07/2020] [Indexed: 12/12/2022]
Abstract
The eukaryotic plasma membrane's lipid composition is found to be ubiquitously asymmetric comparing inner and outer leaflets. This membrane lipid asymmetry plays a crucial role in diverse cellular processes critical for cell survival. A specialized set of transmembrane proteins called translocases, or flippases, have evolved to maintain this membrane lipid asymmetry in an energy-dependent manner. One potential consequence of local variations in membrane lipid asymmetry is membrane remodeling, which is essential for cellular processes such as intracellular trafficking. Recently, there has been a surge in the identification and characterization of flippases, which has significantly advanced the understanding of their functional mechanisms. Furthermore, there are intriguing possibilities for a coupling between membrane curvature and flippase activity. In this review we highlight studies that link membrane shape and remodeling to differential stresses generated by the activity of lipid flippases with an emphasis on data obtained through model membrane systems. We review the common mechanistic models of flippase-mediated lipid flipping and discuss common techniques used to test lipid flippase activity. We then compare the existing data on lipid translocation rates by flippases and conclude with potential future directions for this field.
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Affiliation(s)
- Sankalp Shukla
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Tobias Baumgart
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, United States.
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35
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Structural dynamics of ABC transporters: molecular simulation studies. Biochem Soc Trans 2021; 49:405-414. [PMID: 33634827 DOI: 10.1042/bst20200710] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 02/02/2021] [Accepted: 02/03/2021] [Indexed: 12/31/2022]
Abstract
The biological activities of living organisms involve various inputs and outputs. The ATP-driven substances (biomolecules) responsible for these kinds of activities through membrane (i.e. uptake and efflux of substrates) include ATP-binding cassette (ABC) transporters, some of which play important roles in multidrug resistance. The basic architecture of ABC transporters comprises transmembrane domains (TMDs) and nucleotide-binding domains (NBDs). The functional dynamics (substrate transport) of ABC transporters are realized by concerted motions, such as NBD dimerization, mechanical transmission via coupling helices (CHs), and the translocation of substrates through TMDs, which are induced by the binding and/or hydrolysis of ATP molecules and substrates. In this mini-review, we briefly discuss recent progresses in the structural dynamics as revealed by molecular simulation studies at all-atom (AA), coarse-grained (CG), and quantum mechanics/molecular mechanics (QM/MM) levels.
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36
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Feng T, He X, Zhuo R, Qiao G, Han X, Qiu W, Chi L, Zhang D, Liu M. Identification and functional characterization of ABCC transporters for Cd tolerance and accumulation in Sedum alfredii Hance. Sci Rep 2020; 10:20928. [PMID: 33262396 PMCID: PMC7708633 DOI: 10.1038/s41598-020-78018-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 11/09/2020] [Indexed: 12/20/2022] Open
Abstract
Cd is one of the potential toxic elements (PTEs) exerting great threats on the environment and living organisms and arising extensive attentions worldwide. Sedum alfredii Hance, a Cd hyperaccumulator, is of great importance in studying the mechanisms of Cd hyperaccumulation and has potentials for phytoremediation. ATP-binding cassette sub-family C (ABCC) belongs to the ABC transporter family, which is deemed to closely associate with multiple physiological processes including cellular homeostasis, metal detoxification, and transport of metabolites. In the present work, ten ABCC proteins were identified in S. alfredii Hance, exhibiting uniform domain structure and divergently clustering with those from Arabidopsis. Tissue-specific expression analysis indicated that some SaABCC genes had significantly higher expression in roots (Sa23221 and Sa88F144), stems (Sa13F200 and Sa14F98) and leaves (Sa13F200). Co-expression network analysis using these five SaABCC genes as hub genes produced two clades harboring different edge genes. Transcriptional expression profiles responsive to Cd illustrated a dramatic elevation of Sa14F190 and Sa18F186 genes. Heterologous expression in a Cd-sensitive yeast cell line, we confirmed the functions of Sa14F190 gene encoding ABCC in Cd accumulation. Our study performed a comprehensive analysis of ABCCs in S. alfredii Hance, firstly mapped their tissue-specific expression patterns responsive to Cd stress, and characterized the roles of Sa14F190 genes in Cd accumulation.
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Affiliation(s)
- Tongyu Feng
- Research Institute of Subtropical of Forestry, Chinese Academy of Forestry, Hangzhou, 311400, People's Republic of China
| | - Xuelian He
- Research Institute of Subtropical of Forestry, Chinese Academy of Forestry, Hangzhou, 311400, People's Republic of China
| | - Renying Zhuo
- Research Institute of Subtropical of Forestry, Chinese Academy of Forestry, Hangzhou, 311400, People's Republic of China
| | - Guirong Qiao
- Research Institute of Subtropical of Forestry, Chinese Academy of Forestry, Hangzhou, 311400, People's Republic of China
| | - Xiaojiao Han
- Research Institute of Subtropical of Forestry, Chinese Academy of Forestry, Hangzhou, 311400, People's Republic of China
| | - Wenmin Qiu
- Research Institute of Subtropical of Forestry, Chinese Academy of Forestry, Hangzhou, 311400, People's Republic of China
| | - Linfeng Chi
- School of Basic Medical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, People's Republic of China
| | - Dayi Zhang
- School of Environment, Tsinghua University, Beijing, 100084, People's Republic of China.
| | - Mingying Liu
- School of Basic Medical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, People's Republic of China.
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37
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Bordignon E, Seeger MA, Galazzo L, Meier G. From in vitro towards in situ: structure-based investigation of ABC exporters by electron paramagnetic resonance spectroscopy. FEBS Lett 2020; 594:3839-3856. [PMID: 33219535 DOI: 10.1002/1873-3468.14004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 10/30/2020] [Accepted: 11/15/2020] [Indexed: 12/12/2022]
Abstract
ATP-binding cassette (ABC) exporters have been studied now for more than four decades, and recent structural investigation has produced a large number of protein database entries. Yet, important questions about how ABC exporters function at the molecular level remain debated, such as which are the molecular recognition hotspots and the allosteric couplings dynamically regulating the communication between the catalytic cycle and the export of substrates. This conundrum mainly arises from technical limitations confining all research to in vitro analysis of ABC transporters in detergent solutions or embedded in membrane-mimicking environments. Therefore, a largely unanswered question is how ABC exporters operate in situ, namely in the native membrane context of a metabolically active cell. This review focuses on novel mechanistic insights into type I ABC exporters gained through a unique combination of structure determination, biochemical characterization, generation of conformation-specific nanobodies/sybodies and double electron-electron resonance.
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Affiliation(s)
- Enrica Bordignon
- Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Bochum, Germany
| | - Markus A Seeger
- Institute of Medical Microbiology, University of Zurich, Switzerland
| | - Laura Galazzo
- Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Bochum, Germany
| | - Gianmarco Meier
- Institute of Medical Microbiology, University of Zurich, Switzerland
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38
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Martinez M, Fendley GA, Saxberg AD, Zoghbi ME. Stimulation of the human mitochondrial transporter ABCB10 by zinc-mesoporphrin. PLoS One 2020; 15:e0238754. [PMID: 33253225 PMCID: PMC7703921 DOI: 10.1371/journal.pone.0238754] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 11/06/2020] [Indexed: 11/19/2022] Open
Abstract
Heme biosynthesis occurs through a series of reactions that take place within the cytoplasm and mitochondria, so intermediates need to move across these cellular compartments. However, the specific membrane transport mechanisms involved in the process are not yet identified. The ATP-binding cassette protein ABCB10 is essential for normal heme production, as knocking down this transporter in mice is embryonically lethal and accompanied by severe anemia plus oxidative damage. The role of ABCB10 is unknown, but given its location in the inner mitochondrial membrane, it has been proposed as a candidate to export either an early heme precursor or heme. Alternatively, ABCB10 might transport a molecule important for protection against oxidative damage. To help discern between these possibilities, we decided to study the effect of heme analogs, precursors, and antioxidant peptides on purified human ABCB10. Since substrate binding increases the ATP hydrolysis rate of ABC transporters, we have determined the ability of these molecules to activate purified ABCB10 reconstituted in lipid nanodiscs using ATPase measurements. Under our experimental conditions, we found that the only heme analog increasing ABCB10 ATPase activity was Zinc-mesoporphyrin. This activation of almost seventy percent was specific for ABCB10, as the ATPase activity of a negative control bacterial ABC transporter was not affected. The activation was also observed in cysteine-less ABCB10, suggesting that Zinc-mesoporphyrin's effect did not require binding to typical heme regulatory motifs. Furthermore, our data indicate that ABCB10 was not directly activated by neither the early heme precursor delta-aminolevulinic acid nor glutathione, downsizing their relevance as putative substrates for this transporter. Although additional studies are needed to determine the physiological substrate of ABCB10, our findings reveal Zinc-mesoporphyrin as the first tool compound to directly modulate ABCB10 activity and raise the possibility that some actions of Zinc-mesoporphyrin in cellular and animal studies could be mediated by ABCB10.
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Affiliation(s)
- Melissa Martinez
- Department of Molecular Cell Biology, School of Natural Sciences, University of California Merced, Merced, California, United States of America
| | - Gregory A. Fendley
- Department of Molecular Cell Biology, School of Natural Sciences, University of California Merced, Merced, California, United States of America
| | - Alexandra D. Saxberg
- Department of Molecular Cell Biology, School of Natural Sciences, University of California Merced, Merced, California, United States of America
| | - Maria E. Zoghbi
- Department of Molecular Cell Biology, School of Natural Sciences, University of California Merced, Merced, California, United States of America
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39
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Srikant S. Evolutionary history of ATP-binding cassette proteins. FEBS Lett 2020; 594:3882-3897. [PMID: 33145769 DOI: 10.1002/1873-3468.13985] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 10/01/2020] [Accepted: 10/15/2020] [Indexed: 12/11/2022]
Abstract
ATP-binding cassette (ABC) proteins are found in every sequenced genome and evolved deep in the phylogenetic tree of life. ABC proteins form one of the largest homologous protein families, with most being involved in substrate transport across biological membranes, and a few cytoplasmic members regulating in essential processes like translation. The predominant ABC protein classification scheme is derived from human members, but the increasing number of fully sequenced genomes permits to reevaluate this paradigm in the light of the evolutionary history the ABC-protein superfamily. As we study the diversity of substrates, mechanisms, and physiological roles of ABC proteins, knowledge of the evolutionary relationships highlights similarities and differences that can be attributed to specific branches in protein divergence. While alignments and trees built on natural sequence variation account for the evolutionary divergence of ABC proteins, high-throughput experiments and next-generation sequencing creating experimental sequence variation are instrumental in identifying functional constraints. The combination of natural and experimentally produced sequence variation allows a broader and more rational study of the function and physiological roles of ABC proteins.
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Affiliation(s)
- Sriram Srikant
- Department of Biology, Massachusetts Institute of Technology
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40
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Lewinson O, Orelle C, Seeger MA. Structures of ABC transporters: handle with care. FEBS Lett 2020; 594:3799-3814. [PMID: 33098660 PMCID: PMC7756565 DOI: 10.1002/1873-3468.13966] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/22/2020] [Accepted: 10/15/2020] [Indexed: 12/11/2022]
Abstract
In the past two decades, the ATP‐binding cassette (ABC) transporters' field has undergone a structural revolution. The importance of structural biology to the development of the field of ABC transporters cannot be overstated, as the ensemble of structures not only revealed the architecture of ABC transporters but also shaped our mechanistic view of these remarkable molecular machines. Nevertheless, we advocate that the mechanistic interpretation of the structures is not trivial and should be carried out with prudence. Herein, we bring several examples of structures of ABC transporters that merit re‐interpretation via careful comparison to experimental data. We propose that it is of the upmost importance to place new structures within the context of the available experimental data.
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Affiliation(s)
- Oded Lewinson
- Department of Molecular Microbiology and the Rappaport Institute for Medical Sciences, Faculty of Medicine, The Technion-Israel Institute of Technology, Haifa, Israel
| | - Cédric Orelle
- CNRS, Molecular Microbiology and Structural Biochemistry (MMSB, UMR 5086), University of Lyon, Lyon, France
| | - Markus A Seeger
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
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41
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Breuss MW, Mamerto A, Renner T, Waters ER. The Evolution of the Mammalian ABCA6-like Genes: Analysis of Phylogenetic, Expression, and Population Genetic Data Reveals Complex Evolutionary Histories. Genome Biol Evol 2020; 12:2093-2106. [PMID: 32877505 PMCID: PMC7674697 DOI: 10.1093/gbe/evaa179] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/21/2020] [Indexed: 01/25/2023] Open
Abstract
ABC membrane transporters are a large and complex superfamily of ATP-binding cassette transporters that are present in all domains of life. Both their essential function and complexity are reflected by their retention across large expanses of organismal diversity and by the extensive expansion of individual members and subfamilies during evolutionary history. This expansion has resulted in the diverse ABCA transporter family that has in turn evolved into multiple subfamilies. Here, we focus on the ABCA6-like subfamily of ABCA transporters with the goal of understanding their evolutionary history including potential functional changes in, or loss of, individual members. Our analysis finds that ABCA6-like genes, consisting of ABCA6, 8, 9, and 10, are absent from representatives of both monotremes and marsupials and thus the duplications that generated these families most likely occurred at the base of the Eutherian or placental mammals. We have found evidence of both positive and relaxed selection among the ABCA6-like genes, suggesting dynamic changes in function and the potential of gene redundancy. Analysis of the ABCA10 genes further suggests that this gene has undergone relaxed selection only within the human lineage. These findings are complemented by human population data, where we observe an excess of deactivating homozygous mutations. We describe the complex evolutionary history of this ABCA transporter subfamily and demonstrate through the combination of evolutionary and population genetic analysis that ABCA10 is undergoing pseudogenization within humans.
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Affiliation(s)
- Martin W Breuss
- Department of Neurosciences, University of California, San Diego
- Rady Children’s Institute for Genomic Medicine, San Diego, California
| | - Allen Mamerto
- Department of Biology and Program in Biological and Medical Informatics, San Diego State University
| | - Tanya Renner
- Department of Entomology, The Pennsylvania State University, University Park
| | - Elizabeth R Waters
- Department of Biology and Program in Biological and Medical Informatics, San Diego State University
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42
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Abstract
Cholesterol homeostasis and trafficking are critical to the maintenance of the asymmetric plasma membrane of eukaryotic cells. Disruption or dysfunction of cholesterol trafficking leads to numerous human diseases. ATP-binding cassette (ABC) transporters play several critical roles in this process, and mutations in these sterol transporters lead to disorders such as Tangier disease and sitosterolemia. Biochemical and structural information on ABC sterol transporters is beginning to emerge, with published structures of ABCA1 and ABCG5/G8; these two proteins function in the reverse cholesterol transport pathway and mediate the efflux of cholesterol and xenosterols to high-density lipoprotein and bile salt micelles, respectively. Although both of these transporters belong to the ABC family and mediate the efflux of a sterol substrate, they have many distinct differences. Here, we summarize the current understanding of sterol transport driven by ABC transporters, with an emphasis on these two extensively characterized transporters.
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Affiliation(s)
- Ashlee M Plummer
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA;
| | - Alan T Culbertson
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA;
| | - Maofu Liao
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA;
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43
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Sarkadi B, Homolya L, Hegedűs T. The ABCG2/BCRP transporter and its variants - from structure to pathology. FEBS Lett 2020; 594:4012-4034. [PMID: 33015850 DOI: 10.1002/1873-3468.13947] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 08/27/2020] [Accepted: 09/21/2020] [Indexed: 12/13/2022]
Abstract
The ABCG2 protein has a key role in the transport of a wide range of structurally dissimilar endo- and xenobiotics in the human body, especially in the tissue barriers and the metabolizing or secreting organs. The human ABCG2 gene harbors a high number of polymorphisms and mutations, which may significantly modulate its expression and function. Recent high-resolution structural data, complemented with molecular dynamic simulations, may significantly help to understand intramolecular movements and substrate handling, as well as the effects of mutations on the membrane transporter function of ABCG2. As reviewed here, structural alterations may result not only in direct alterations in drug binding and transporter activity, but also in improper folding or problems in the carefully regulated process of trafficking, including vesicular transport, endocytosis, recycling, and degradation. Here, we also review the clinical importance of altered ABCG2 expression and function in general drug metabolism, cancer multidrug resistance, and impaired uric acid excretion, leading to gout.
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Affiliation(s)
- Balázs Sarkadi
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary.,Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - László Homolya
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
| | - Tamás Hegedűs
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
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44
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Chi X, Fan Q, Zhang Y, Liang K, Wan L, Zhou Q, Li Y. Structural mechanism of phospholipids translocation by MlaFEDB complex. Cell Res 2020; 30:1127-1135. [PMID: 32884137 PMCID: PMC7784689 DOI: 10.1038/s41422-020-00404-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Accepted: 08/14/2020] [Indexed: 12/16/2022] Open
Abstract
In Gram-negative bacteria, phospholipids are major components of the inner membrane and the inner leaflet of the outer membrane, playing an essential role in forming the unique dual-membrane barrier to exclude the entry of most antibiotics. Understanding the mechanisms of phospholipid translocation between the inner and outer membrane represents one of the major challenges surrounding bacterial phospholipid homeostasis. The conserved MlaFEDB complex in the inner membrane functions as an ABC transporter to drive the translocation of phospholipids between the inner membrane and the periplasmic protein MlaC. However, the mechanism of phospholipid translocation remains elusive. Here we determined three cryo-EM structures of MlaFEDB from Escherichia coli in its nucleotide-free and ATP-bound conformations, and performed extensive functional studies to verify and extend our findings from structural analyses. Our work reveals unique structural features of the entire MlaFEDB complex, six well-resolved phospholipids in three distinct cavities, and large-scale conformational changes upon ATP binding. Together, these findings define the cycle of structural rearrangement of MlaFEDB in action, and suggest that MlaFEDB uses an extrusion mechanism to extract and release phospholipids through the central translocation cavity.
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Affiliation(s)
- Ximin Chi
- Center for Infectious Disease Research, Zhejiang Provincial Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China.,Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China
| | - Qiongxuan Fan
- Center for Infectious Disease Research, Zhejiang Provincial Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China.,Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China
| | - Yuanyuan Zhang
- Center for Infectious Disease Research, Zhejiang Provincial Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China.,Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China
| | - Ke Liang
- Center for Infectious Disease Research, Zhejiang Provincial Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China.,Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China
| | - Li Wan
- Center for Infectious Disease Research, Zhejiang Provincial Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China.,Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China
| | - Qiang Zhou
- Center for Infectious Disease Research, Zhejiang Provincial Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China. .,Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China.
| | - Yanyan Li
- Center for Infectious Disease Research, Zhejiang Provincial Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China. .,Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China.
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45
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Effects of Ischemia-Reperfusion on Tubular Cell Membrane Transporters and Consequences in Kidney Transplantation. J Clin Med 2020; 9:jcm9082610. [PMID: 32806541 PMCID: PMC7464608 DOI: 10.3390/jcm9082610] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 07/31/2020] [Accepted: 08/06/2020] [Indexed: 12/12/2022] Open
Abstract
Ischemia-reperfusion (IR)-induced acute kidney injury (IRI) is an inevitable event in kidney transplantation. It is a complex pathophysiological process associated with numerous structural and metabolic changes that have a profound influence on the early and the late function of the transplanted kidney. Proximal tubular cells are particularly sensitive to IRI. These cells are involved in renal and whole-body homeostasis, detoxification processes and drugs elimination by a transporter-dependent, transcellular transport system involving Solute Carriers (SLCs) and ATP Binding Cassettes (ABCs) transporters. Numerous studies conducted mainly in animal models suggested that IRI causes decreased expression and activity of some major tubular transporters. This could favor uremic toxins accumulation and renal metabolic alterations or impact the pharmacokinetic/toxicity of drugs used in transplantation. It is of particular importance to understand the underlying mechanisms and effects of IR on tubular transporters in order to improve the mechanistic understanding of IRI pathophysiology, identify biomarkers of graft function or promote the design and development of novel and effective therapies. Modulation of transporters’ activity could thus be a new therapeutic opportunity to attenuate kidney injury during IR.
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46
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Göddeke H, Schäfer LV. Capturing Substrate Translocation in an ABC Exporter at the Atomic Level. J Am Chem Soc 2020; 142:12791-12801. [PMID: 32578427 DOI: 10.1021/jacs.0c05502] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
ATP-binding cassette (ABC) transporters chemomechanically couple ATP binding and hydrolysis to large-scale conformational changes, ultimately leading to substrate translocation across biological membranes. Despite recent progress in the structure determination of substrate-bound ABC exporters, the inherently dynamic mechanism of substrate transport remains unclear at the atomic level. In this work, we capture substrate translocation in the heterodimeric ABC exporter TM287/288 from the hyperthermophilic bacterium Thermotoga maritima using all-atom molecular dynamics (MD) simulations. Unguided multimicrosecond simulations at 375 K show how the drugs daunorubicin and verapamil, which were initially docked into the ABC transporter, get translocated through the exporter by following its large-scale alternating access conformational transitions between an inward-facing (IF) and an outward-facing (OF) conformation. Triggered by the affinity difference due to differential solvation of the binding cavity in the IF and OF conformations, the substrates unbind from the OF transporter and partition into the lipid bilayer. While daunorubicin is stably inserted into the outer leaflet of the bilayer, verapamil dynamically flip flops between the bilayer leaflets, possibly rendering its net transport futile.
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Affiliation(s)
- Hendrik Göddeke
- Theoretical Chemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44780 Bochum, Germany
| | - Lars V Schäfer
- Theoretical Chemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44780 Bochum, Germany
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47
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Wang L, Johnson ZL, Wasserman MR, Levring J, Chen J, Liu S. Characterization of the kinetic cycle of an ABC transporter by single-molecule and cryo-EM analyses. eLife 2020; 9:56451. [PMID: 32458799 PMCID: PMC7253176 DOI: 10.7554/elife.56451] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 05/15/2020] [Indexed: 01/21/2023] Open
Abstract
ATP-binding cassette (ABC) transporters are molecular pumps ubiquitous across all kingdoms of life. While their structures have been widely reported, the kinetics governing their transport cycles remain largely unexplored. Multidrug resistance protein 1 (MRP1) is an ABC exporter that extrudes a variety of chemotherapeutic agents and native substrates. Previously, the structures of MRP1 were determined in an inward-facing (IF) or outward-facing (OF) conformation. Here, we used single-molecule fluorescence spectroscopy to track the conformational changes of bovine MRP1 (bMRP1) in real time. We also determined the structure of bMRP1 under active turnover conditions. Our results show that substrate stimulates ATP hydrolysis by accelerating the IF-to-OF transition. The rate-limiting step of the transport cycle is the dissociation of the nucleotide-binding-domain dimer, while ATP hydrolysis per se does not reset MRP1 to the resting state. The combination of structural and kinetic data illustrates how different conformations of MRP1 are temporally linked and how substrate and ATP alter protein dynamics to achieve active transport.
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Affiliation(s)
- Ling Wang
- Laboratory of Nanoscale Biophysics and Biochemistry, The Rockefeller University, New York, United States
| | - Zachary Lee Johnson
- Laboratory of Membrane Biology and Biophysics, The Rockefeller University, New York, United States
| | - Michael R Wasserman
- Laboratory of Nanoscale Biophysics and Biochemistry, The Rockefeller University, New York, United States
| | - Jesper Levring
- Laboratory of Membrane Biology and Biophysics, The Rockefeller University, New York, United States
| | - Jue Chen
- Laboratory of Membrane Biology and Biophysics, The Rockefeller University, New York, United States.,Howard Hughes Medical Institute, The Rockefeller University, New York, United States
| | - Shixin Liu
- Laboratory of Nanoscale Biophysics and Biochemistry, The Rockefeller University, New York, United States
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48
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Thélot F, Orlando BJ, Li Y, Liao M. High-resolution views of lipopolysaccharide translocation driven by ABC transporters MsbA and LptB 2FGC. Curr Opin Struct Biol 2020; 63:26-33. [PMID: 32335504 DOI: 10.1016/j.sbi.2020.03.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 02/18/2020] [Accepted: 03/06/2020] [Indexed: 12/16/2022]
Abstract
Gram-negative bacteria possess a dual-membrane envelope, which provides defense against environmental assault, as well as formidable resistance against antibiotics. Lipopolysaccharide (LPS) is the primary lipid component in the outermost membrane leaflet of most Gram-negative bacteria, and plays critical roles in cell envelope formation. Newly synthesized LPS at the cytoplasmic side of the inner membrane is flipped across the inner membrane and pushed across the periplasm by two ATP-binding cassette transporters, MsbA and LptB2FGC, respectively. Both transporters represent promising targets for developing new classes of antibiotics. In this review, we discuss recent advances in understanding the mechanism of LPS translocation driven by MsbA and LptB2FGC, with a particular focus on new findings from structural studies.
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Affiliation(s)
- François Thélot
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Biological and Biomedical Sciences Program, Harvard University, Cambridge, MA 02138, USA
| | - Benjamin J Orlando
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Yanyan Li
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou 310024, China.
| | - Maofu Liao
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
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49
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Srikant S, Gaudet R, Murray AW. Selecting for Altered Substrate Specificity Reveals the Evolutionary Flexibility of ATP-Binding Cassette Transporters. Curr Biol 2020; 30:1689-1702.e6. [PMID: 32220325 PMCID: PMC7243462 DOI: 10.1016/j.cub.2020.02.077] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 01/20/2020] [Accepted: 02/24/2020] [Indexed: 12/12/2022]
Abstract
ATP-binding cassette (ABC) transporters are the largest family of ATP-hydrolyzing transporters, which import or export substrates across membranes, and have members in every sequenced genome. Structural studies and biochemistry highlight the contrast between the global structural similarity of homologous transporters and the enormous diversity of their substrates. How do ABC transporters evolve to carry such diverse molecules and what variations in their amino acid sequence alter their substrate selectivity? We mutagenized the transmembrane domains of a conserved fungal ABC transporter that exports a mating pheromone and selected for mutants that export a non-cognate pheromone. Mutations that alter export selectivity cover a region that is larger than expected for a localized substrate-binding site. Individual selected clones have multiple mutations, which have broadly additive contributions to specific transport activity. Our results suggest that multiple positions influence substrate selectivity, leading to alternative evolutionary paths toward selectivity for particular substrates and explaining the number and diversity of ABC transporters. Srikant et al. find that mutations at many different positions in an ABC transporter of fungal mating pheromone have roughly additive effects on substrate recognition. This helps explain the evolvability of ABC transporters to transport a remarkable variety of substrates and their presence as the largest protein family across all domains of life.
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Affiliation(s)
- Sriram Srikant
- Department of Molecular and Cellular Biology, Harvard University, 52 Oxford Street, Cambridge, MA 02138, USA
| | - Rachelle Gaudet
- Department of Molecular and Cellular Biology, Harvard University, 52 Oxford Street, Cambridge, MA 02138, USA.
| | - Andrew W Murray
- Department of Molecular and Cellular Biology, Harvard University, 52 Oxford Street, Cambridge, MA 02138, USA.
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50
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Cryo-EM structure of human bile salts exporter ABCB11. Cell Res 2020; 30:623-625. [PMID: 32203132 DOI: 10.1038/s41422-020-0302-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 03/04/2020] [Indexed: 11/08/2022] Open
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