1
|
Thévenod F, Lee WK. Cadmium transport by mammalian ATP-binding cassette transporters. Biometals 2024; 37:697-719. [PMID: 38319451 PMCID: PMC11101381 DOI: 10.1007/s10534-024-00582-5] [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: 09/15/2023] [Accepted: 01/04/2024] [Indexed: 02/07/2024]
Abstract
Cellular responses to toxic metals depend on metal accessibility to intracellular targets, reaching interaction sites, and the intracellular metal concentration, which is mainly determined by uptake pathways, binding/sequestration and efflux pathways. ATP-binding cassette (ABC) transporters are ubiquitous in the human body-usually in epithelia-and are responsible for the transfer of indispensable physiological substrates (e.g. lipids and heme), protection against potentially toxic substances, maintenance of fluid composition, and excretion of metabolic waste products. Derailed regulation and gene variants of ABC transporters culminate in a wide array of pathophysiological disease states, such as oncogenic multidrug resistance or cystic fibrosis. Cadmium (Cd) has no known physiological role in mammalians and poses a health risk due to its release into the environment as a result of industrial activities, and eventually passes into the food chain. Epithelial cells, especially within the liver, lungs, gastrointestinal tract and kidneys, are particularly susceptible to the multifaceted effects of Cd because of the plethora of uptake pathways available. Pertinent to their broad substrate spectra, ABC transporters represent a major cellular efflux pathway for Cd and Cd complexes. In this review, we summarize current knowledge concerning transport of Cd and its complexes (mainly Cd bound to glutathione) by the ABC transporters ABCB1 (P-glycoprotein, MDR1), ABCB6, ABCC1 (multidrug resistance related protein 1, MRP1), ABCC7 (cystic fibrosis transmembrane regulator, CFTR), and ABCG2 (breast cancer related protein, BCRP). Potential detoxification strategies underlying ABC transporter-mediated efflux of Cd and Cd complexes are discussed.
Collapse
Affiliation(s)
- Frank Thévenod
- Institute for Physiology, Pathophysiology and Toxicology & ZBAF, Witten/Herdecke University, 58453, Witten, Germany
- Physiology and Pathophysiology of Cells and Membranes, Medical School OWL, Bielefeld University, Morgenbreede 1, 33615, Bielefeld, Germany
| | - Wing-Kee Lee
- Physiology and Pathophysiology of Cells and Membranes, Medical School OWL, Bielefeld University, Morgenbreede 1, 33615, Bielefeld, Germany.
| |
Collapse
|
2
|
Sohail I, Hassan MU, Schmid D, Chiba P. The noncanonical nucleotide binding site 1 of the bile salt export pump is optimized for proper function of the transporter. Cell Biol Int 2024; 48:638-646. [PMID: 38328902 DOI: 10.1002/cbin.12136] [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: 08/15/2023] [Revised: 12/19/2023] [Accepted: 01/28/2024] [Indexed: 02/09/2024]
Abstract
The bile salt export pump (ABCB11/BSEP) is a hepatocyte plasma membrane-resident protein translocating bile salts into bile canaliculi. The sequence alignment of the four full-length transporters of the ABCB subfamily (ABCB1, ABCB4, ABCB5 and ABCB11) indicates that the NBD-NBD contact interface of ABCB11 differs from that of other members in only four residues. Notably, these are all located in the noncanonical nucleotide binding site 1 (NBS1). Substitution of all four deviant residues with canonical ones (quadruple mutant) significantly decreased the transport activity of the protein. In this study, we mutated two deviant residues in the signature sequence to generate a double mutant (R1221G/E1223Q). Furthermore, a triple mutant (E502S/R1221G/E1223Q) was generated, in which the deviant residues of the signature sequence and Q-loop were mutated concurrently to canonical residues. The double and triple mutants showed 80% and 60%, respectively, of the activity of wild-type BSEP. As expected, an increasing number of mutations gradually impair transport as an intricate network of interactions within the ABC proteins ensures proper functioning.
Collapse
Affiliation(s)
- Imran Sohail
- Department of Zoology, Government College University Lahore, Lahore, Pakistan
- Institute of Medical Chemistry, Medical University of Vienna, Vienna, Austria
| | - Mahmood Ul Hassan
- Institute of Medical Chemistry, Medical University of Vienna, Vienna, Austria
- Institute of Industrial Biotechnology, Government College University Lahore, Lahore, Pakistan
| | - Diethart Schmid
- Institute of Physiology, Medical University of Vienna, Vienna, Austria
| | - Peter Chiba
- Institute of Medical Chemistry, Medical University of Vienna, Vienna, Austria
| |
Collapse
|
3
|
Dot EW, Thomason LC, Chappie JS. Everything OLD is new again: How structural, functional, and bioinformatic advances have redefined a neglected nuclease family. Mol Microbiol 2023; 120:122-140. [PMID: 37254295 DOI: 10.1111/mmi.15074] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 04/28/2023] [Accepted: 04/30/2023] [Indexed: 06/01/2023]
Abstract
Overcoming lysogenization defect (OLD) proteins are a conserved family of ATP-powered nucleases that function in anti-phage defense. Recent bioinformatic, genetic, and crystallographic studies have yielded new insights into the structure, function, and evolution of these enzymes. Here we review these developments and propose a new classification scheme to categorize OLD homologs that relies on gene neighborhoods, biochemical properties, domain organization, and catalytic machinery. This taxonomy reveals important similarities and differences between family members and provides a blueprint to contextualize future in vivo and in vitro findings. We also detail how OLD nucleases are related to PARIS and Septu anti-phage defense systems and discuss important mechanistic questions that remain unanswered.
Collapse
Affiliation(s)
- Elena Wanvig Dot
- Department of Molecular Medicine, Cornell University, Ithaca, New York, USA
| | - Lynn C Thomason
- Molecular Control and Genetics Section, RNA Biology Laboratory, National Cancer Institute at Frederick, National Institutes of Health, Frederick, Maryland, USA
| | - Joshua S Chappie
- Department of Molecular Medicine, Cornell University, Ithaca, New York, USA
| |
Collapse
|
4
|
Bonito C, Ferreira RJ, Ferreira MJ, Durães F, Sousa E, Gillet JP, Cordeiro MNS, dos Santos DJVA. Probing the Allosteric Modulation of P-Glycoprotein: A Medicinal Chemistry Approach Toward the Identification of Noncompetitive P-Gp Inhibitors. ACS OMEGA 2023; 8:11281-11287. [PMID: 37008154 PMCID: PMC10061618 DOI: 10.1021/acsomega.2c08273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 03/01/2023] [Indexed: 06/19/2023]
Abstract
A medicinal chemistry approach combining in silico and in vitro methodologies was performed aiming at identifying and characterizing putative allosteric drug-binding sites (aDBSs) at the interface of the transmembrane- and nucleotide-binding domains (TMD-NBD) of P-glycoprotein. Two aDBSs were identified, one in TMD1/NBD1 and another one in TMD2/NBD2, by means of in silico fragment-based molecular dynamics and characterized in terms of size, polarity, and lining residues. From a small library of thioxanthone and flavanone derivatives, experimentally described to bind at the TMD-NBD interfaces, several compounds were identified to be able to decrease the verapamil-stimulated ATPase activity. An IC50 of 81 ± 6.6 μM is reported for a flavanone derivative in the ATPase assays, providing evidence for an allosteric efflux modulation in P-glycoprotein. Molecular docking and molecular dynamics gave additional insights on the binding mode on how flavanone derivatives may act as allosteric inhibitors.
Collapse
Affiliation(s)
- Cátia
A. Bonito
- LAQV@REQUIMTE,
Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, Rua do Campo Alegre, Porto 4169-007, Portugal
| | - Ricardo J. Ferreira
- Red
Glead Discovery AB, Medicon
Village, Scheelevägen 8, Lund 223 63, Sweden
| | - Maria-José.
U. Ferreira
- Research
Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, Lisbon 1649-003, Portugal
| | - Fernando Durães
- Interdisciplinary
Centre of Marine and Environmental Research (CIIMAR) & Laboratory
of Organic and Pharmaceutical Chemistry, Department of Chemical Sciences,
Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira 228, Porto 4050-313, Portugal
| | - Emília Sousa
- Interdisciplinary
Centre of Marine and Environmental Research (CIIMAR) & Laboratory
of Organic and Pharmaceutical Chemistry, Department of Chemical Sciences,
Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira 228, Porto 4050-313, Portugal
| | - Jean-Pierre Gillet
- Laboratory
of Molecular Cancer Biology, URPhyM, NARILIS, Faculty of Medicine, University of Namur, Namur 5000, Belgium
| | - M. Natália
D. S. Cordeiro
- LAQV@REQUIMTE,
Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, Rua do Campo Alegre, Porto 4169-007, Portugal
| | - Daniel J. V. A. dos Santos
- CBIOS-Center
for Research in Biosciences & Health Technologies, Lusófona University, Campo Grande, 376, Lisboa 1749-024, Portugal
| |
Collapse
|
5
|
Schleker ESM, Buschmann S, Xie H, Welsch S, Michel H, Reinhart C. Structural and functional investigation of ABC transporter STE6-2p from Pichia pastoris reveals unexpected interaction with sterol molecules. Proc Natl Acad Sci U S A 2022; 119:e2202822119. [PMID: 36256814 PMCID: PMC9618074 DOI: 10.1073/pnas.2202822119] [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: 02/16/2022] [Accepted: 09/23/2022] [Indexed: 11/18/2022] Open
Abstract
Adenosine triphosphate (ATP)-binding cassette (ABC) transporters are multidomain transmembrane proteins, which facilitate the transport of various substances across cell membranes using energy derived from ATP hydrolysis. They are important drug targets since they mediate decreased drug susceptibility during pharmacological treatments. For the methylotrophic yeast Pichia pastoris, a model organism that is a widely used host for protein expression, the role and function of its ABC transporters is unexplored. In this work, we investigated the Pichia ABC-B transporter STE6-2p. Functional investigations revealed that STE6-2p is capable of transporting rhodamines in vivo and is active in the presence of verapamil and triazoles in vitro. A phylogenetic analysis displays homology among multidrug resistance (MDR) transporters from pathogenic fungi to human ABC-B transporters. Further, we present high-resolution single-particle electron cryomicroscopy structures of an ABC transporter from P. pastoris in the apo conformation (3.1 Å) and in complex with verapamil and adenylyl imidodiphosphate (AMP-PNP) (3.2 Å). An unknown density between transmembrane helices 4, 5, and 6 in both structures suggests the presence of a sterol-binding site of unknown function.
Collapse
Affiliation(s)
- E. Sabine M. Schleker
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, D-60438 Frankfurt am Main, Germany
| | - Sabine Buschmann
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, D-60438 Frankfurt am Main, Germany
| | - Hao Xie
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, D-60438 Frankfurt am Main, Germany
| | - Sonja Welsch
- Central Electron Microscopy Facility, Max Planck Institute of Biophysics, D-60438 Frankfurt am Main, Germany
| | - Hartmut Michel
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, D-60438 Frankfurt am Main, Germany
| | - Christoph Reinhart
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, D-60438 Frankfurt am Main, Germany
| |
Collapse
|
6
|
Sergent JA, Mathouet H, Hulen C, Lameiras P, Feuilloley M, Elomri A, Lomri NE. Effects of Two Natural Bisbenzylisoquinolines, Curine and Guattegaumerine, Extracted from Isolona hexaloba on Rhodamine Efflux by Abcb1b from Rat Glycocholic-Acid-Resistant Hepatocarcinoma Cells. Molecules 2022; 27:molecules27093030. [PMID: 35566380 PMCID: PMC9099951 DOI: 10.3390/molecules27093030] [Citation(s) in RCA: 1] [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] [Received: 03/27/2022] [Revised: 04/29/2022] [Accepted: 05/05/2022] [Indexed: 02/06/2023] Open
Abstract
To develop new therapeutic molecules, it is essential to understand the biological effects and targets of clinically relevant compounds. In this article, we describe the extraction and characterization of two alkaloids from the roots of Isolona hexaloba—curine and guattegaumerine. The effect of these alkaloids on the multidrug efflux pump ABCB1 (MDR1/P-Glycoprotein) and their antiproliferative properties were studied. Compared to verapamil, a widely used inhibitor of P-gp, curine and guattegaumerine were found to be weak inhibitors of MDR1/P-Glycoprotein. The highest inhibition of efflux produced by verapamil disappeared in the presence of curine or guattegaumerine as competitors, and the most pronounced effect was achieved with curine. Altogether, this work has provided new insights into the biological effects of these alkaloids on the rat Mdr1b P-gp efflux mechanism and would be beneficial in the design of potent P-gp inhibitors.
Collapse
Affiliation(s)
- Jacques-Aurélien Sergent
- Department of Biology, UFR Sciences and Techniques, University of Cergy-Pontoise, 2 Ave A. Chauvin, 95302 Cergy-Pontoise, France;
| | - Hilarion Mathouet
- UNIROUEN, INSA Rouen, CNRS, COBRA (UMR 6014), Normandie University, 76000 Rouen, France; (H.M.); (P.L.)
| | - Christian Hulen
- Bacterial Communication and Antimicrobial Strategies Research Unit, University of Rouen Normandy, 55 rue Saint Germain, 2700 Evreux, France; (C.H.); (M.F.)
| | - Pedro Lameiras
- UNIROUEN, INSA Rouen, CNRS, COBRA (UMR 6014), Normandie University, 76000 Rouen, France; (H.M.); (P.L.)
| | - Marc Feuilloley
- Bacterial Communication and Antimicrobial Strategies Research Unit, University of Rouen Normandy, 55 rue Saint Germain, 2700 Evreux, France; (C.H.); (M.F.)
| | - Abdelhakim Elomri
- UNIROUEN, INSA Rouen, CNRS, COBRA (UMR 6014), Normandie University, 76000 Rouen, France; (H.M.); (P.L.)
- Correspondence: (A.E.); (N.-E.L.); Tel.: +33-235-148-591 (A.E.); +33-134-256-555 (N.-E.L.)
| | - Nour-Eddine Lomri
- Department of Biology, UFR Sciences and Techniques, University of Cergy-Pontoise, 2 Ave A. Chauvin, 95302 Cergy-Pontoise, France;
- Bacterial Communication and Antimicrobial Strategies Research Unit, University of Rouen Normandy, 55 rue Saint Germain, 2700 Evreux, France; (C.H.); (M.F.)
- Correspondence: (A.E.); (N.-E.L.); Tel.: +33-235-148-591 (A.E.); +33-134-256-555 (N.-E.L.)
| |
Collapse
|
7
|
Mechanistic basis for multidrug resistance and collateral drug sensitivity conferred to the malaria parasite by polymorphisms in PfMDR1 and PfCRT. PLoS Biol 2022; 20:e3001616. [PMID: 35507548 PMCID: PMC9067703 DOI: 10.1371/journal.pbio.3001616] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 03/31/2022] [Indexed: 01/16/2023] Open
Abstract
Polymorphisms in the Plasmodium falciparum multidrug resistance protein 1 (pfmdr1) gene and the Plasmodium falciparum chloroquine resistance transporter (pfcrt) gene alter the malaria parasite’s susceptibility to most of the current antimalarial drugs. However, the precise mechanisms by which PfMDR1 contributes to multidrug resistance have not yet been fully elucidated, nor is it understood why polymorphisms in pfmdr1 and pfcrt that cause chloroquine resistance simultaneously increase the parasite’s susceptibility to lumefantrine and mefloquine—a phenomenon known as collateral drug sensitivity. Here, we present a robust expression system for PfMDR1 in Xenopus oocytes that enables direct and high-resolution biochemical characterizations of the protein. We show that wild-type PfMDR1 transports diverse pharmacons, including lumefantrine, mefloquine, dihydroartemisinin, piperaquine, amodiaquine, methylene blue, and chloroquine (but not the antiviral drug amantadine). Field-derived mutant isoforms of PfMDR1 differ from the wild-type protein, and each other, in their capacities to transport these drugs, indicating that PfMDR1-induced changes in the distribution of drugs between the parasite’s digestive vacuole (DV) and the cytosol are a key driver of both antimalarial resistance and the variability between multidrug resistance phenotypes. Of note, the PfMDR1 isoforms prevalent in chloroquine-resistant isolates exhibit reduced capacities for chloroquine, lumefantrine, and mefloquine transport. We observe the opposite relationship between chloroquine resistance-conferring mutations in PfCRT and drug transport activity. Using our established assays for characterizing PfCRT in the Xenopus oocyte system and in live parasite assays, we demonstrate that these PfCRT isoforms transport all 3 drugs, whereas wild-type PfCRT does not. We present a mechanistic model for collateral drug sensitivity in which mutant isoforms of PfMDR1 and PfCRT cause chloroquine, lumefantrine, and mefloquine to remain in the cytosol instead of sequestering within the DV. This change in drug distribution increases the access of lumefantrine and mefloquine to their primary targets (thought to be located outside of the DV), while simultaneously decreasing chloroquine’s access to its target within the DV. The mechanistic insights presented here provide a basis for developing approaches that extend the useful life span of antimalarials by exploiting the opposing selection forces they exert upon PfCRT and PfMDR1.
Collapse
|
8
|
ABCB1 Does Not Require the Side-Chain Hydrogen-Bond Donors Gln 347, Gln 725, Gln 990 to Confer Cellular Resistance to the Anticancer Drug Taxol. Int J Mol Sci 2021; 22:ijms22168561. [PMID: 34445264 PMCID: PMC8395328 DOI: 10.3390/ijms22168561] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/14/2021] [Accepted: 07/28/2021] [Indexed: 01/11/2023] Open
Abstract
The multidrug efflux transporter ABCB1 is clinically important for drug absorption and distribution and can be a determinant of chemotherapy failure. Recent structure data shows that three glutamines donate hydrogen bonds to coordinate taxol in the drug binding pocket. This is consistent with earlier drug structure-activity relationships that implicated the importance of hydrogen bonds in drug recognition by ABCB1. By replacing the glutamines with alanines we have tested whether any, or all, of Gln347, Gln725, and Gln990 are important for the transport of three different drug classes. Flow cytometric transport assays show that Q347A and Q990A act synergistically to reduce transport of Calcein-AM, BODIPY-verapamil, and OREGON GREEN-taxol bisacetate but the magnitude of the effect was dependent on the test drug and no combination of mutations completely abrogated function. Surprisingly, Q725A mutants generally improved transport of Calcein-AM and BODIPY-verapamil, suggesting that engagement of the wild-type Gln725 in a hydrogen bond is inhibitory for the transport mechanism. To test transport of unmodified taxol, stable expression of Q347/725A and the triple mutant was engineered and shown to confer equivalent resistance to the drug as the wild-type transporter, further indicating that none of these potential hydrogen bonds between transporter and transport substrate are critical for the function of ABCB1. The implications of the data for plasticity of the drug binding pocket are discussed.
Collapse
|
9
|
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.
Collapse
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.
| |
Collapse
|
10
|
Cheng F, Pan Q, Gao W, Pu Y, Luo K, He B. Reversing Chemotherapy Resistance by a Synergy between Lysosomal pH-Activated Mitochondrial Drug Delivery and Erlotinib-Mediated Drug Efflux Inhibition. ACS APPLIED MATERIALS & INTERFACES 2021; 13:29257-29268. [PMID: 34130450 DOI: 10.1021/acsami.1c03196] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Mitochondrial drug delivery has attracted increasing attention in various mitochondrial dysfunction-associated disorders such as cancer owing to the important role of energy production. Herein, we report a lysosomal pH-activated mitochondrial-targeting polymer nanoparticle to overcome drug resistance by a synergy between mitochondrial delivery of doxorubicin (DOX, an anticancer drug) and erlotinib-mediated inhibition of drug efflux. The obtained nanoparticles, DE-NPs could maintain negative charge and have long blood circulation while undergoing charge reversal at lysosomal pH after internalization by cancer cells. Thereafter, the acidity-activated polycationic and hydrophobic polypeptide domains boost lysosomal escape and mitochondrial-targeting drug delivery, leading to mitochondrial dysfunction, ATP suppression, and cell apoptosis. Moreover, the suppressed ATP supply and erlotinib enabled dual inhibition of drug efflux by DOX-resistant MCF-7/ADR cells, leading to significantly augmented intracellular DOX accumulation and a synergistic anticancer effect with a 17-fold decrease of IC50 relative to DOX. In vivo antitumor study demonstrates that DE-NPs efficiently suppressed the tumor burden in MCF-7/ADR tumor-bearing mice and led to negligible toxicity. This work establishes that a combination of mitochondrial drug delivery and drug efflux inhibition could be a promising strategy for combating multidrug resistance.
Collapse
Affiliation(s)
- Furong Cheng
- National Engineering Research Center for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu 610064, China
- Center for Translational Medicine, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou 510260, China
- Department of Pharmaceutics, College of Pharmacy, Virginia Commonwealth University, Richmond 23219, Virginia, United States
| | - Qingqing Pan
- National Engineering Research Center for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu 610064, China
| | - Wenxia Gao
- College of Chemistry & Materials Engineering, Wenzhou University, Wenzhou 325027, China
| | - Yuji Pu
- National Engineering Research Center for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu 610064, China
| | - Kui Luo
- Huaxi MR Research Center, Department of Radiology, West China Hospital, Functional and Molecular Imaging Key Laboratory of Sichuan Province, Sichuan University, Chengdu 610041, China
| | - Bin He
- National Engineering Research Center for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu 610064, China
| |
Collapse
|
11
|
Mahmud S, Islam MJ, Parves MR, Khan MA, Tabussum L, Ahmed S, Ali MA, Fakayode SO, Halim MA. Designing potent inhibitors against the multidrug resistance P-glycoprotein. J Biomol Struct Dyn 2021; 40:9403-9415. [PMID: 34060432 DOI: 10.1080/07391102.2021.1930159] [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] [Indexed: 12/14/2022]
Abstract
The multidrug transporter P-glycoprotein is an ATP binding cassette (ABC) exporter responsible for resistance to tumor cells during chemotherapy. This study was designed with computational approaches aimed at identifying the best potent inhibitors of P-glycoprotein. Although many compounds have been suggested to inhibit P-glycoprotein, however, their information on bioavailability, selectivity, ADMET properties, and molecular interactions has not been revealed. Molecular docking, ADMET analysis, molecular dynamics, Principal component analysis (PCA), and binding free energy calculations were performed. Two compounds D1 and D2 showed the best docking score against P-glycoprotein and both compounds have 4-thiazolidinone derivatives containing indolin-3 one moiety are novel anti-tumor compounds. ADMET calculation analysis predicted D1 and D2 to have acceptable pharmacokinetic properties. The MD simulation discloses that D1-P-glycoprotein and D2-P-glycoprotein complexes are in stable conformation as apo-form. Hydrophobic amino acid such as phenylalanine plays significant on the interactions of inhibitors. Principal component analysis shows that both complexes are relatively similar variables as apo-form except planarity and Columbo energy profile. In addition, Quantitative Structural Activity Relationship (QSAR) of the ligand candidates were subjected to the principal component analysis (PCA) for pattern recognition. Partial-least-square (PLS) regression analysis was further utilized to model drug candidates' QSAR for subsequent prediction of the binding energy of validated drug candidates. PCA revealed groupings of the drug candidates based on the similarity or differences in drug candidates QSAR. Moreover, the developed PLS regression accurately predicted the values of the binding energy of drug candidates, with low residual error of prediction.Communicated by Ramaswamy H. Sarma.
Collapse
Affiliation(s)
- Shafi Mahmud
- Division of Computer Aided Drug-Design, The Red-Green Research Center, BICCB, Tejgaon, Dhaka, Bangladesh.,Department of Genetic Engineering and Biotechnology, University of Rajshahi, Rajshahi, Bangladesh
| | - Md Jahirul Islam
- Division of Computer Aided Drug-Design, The Red-Green Research Center, BICCB, Tejgaon, Dhaka, Bangladesh
| | - Md Rimon Parves
- Division of Computer Aided Drug-Design, The Red-Green Research Center, BICCB, Tejgaon, Dhaka, Bangladesh.,Department of Biochemistry and Biotechnology, University of Science and Technology Chittagong (USTC), Chittagong, Bangladesh
| | - Md Arif Khan
- Division of Computer Aided Drug-Design, The Red-Green Research Center, BICCB, Tejgaon, Dhaka, Bangladesh.,Department of Biotechnology and Genetic Engineering, University of Development Alternative (UODA), Dhaka, Bangladesh
| | - Lamiya Tabussum
- Division of Computer Aided Drug-Design, The Red-Green Research Center, BICCB, Tejgaon, Dhaka, Bangladesh.,Department of Genetic Engineering and Biotechnology, University of Rajshahi, Rajshahi, Bangladesh
| | - Sinthyia Ahmed
- Division of Computer Aided Drug-Design, The Red-Green Research Center, BICCB, Tejgaon, Dhaka, Bangladesh
| | - Md Ackas Ali
- Division of Computer Aided Drug-Design, The Red-Green Research Center, BICCB, Tejgaon, Dhaka, Bangladesh
| | - Sayo O Fakayode
- Department of Physical Sciences, University of Arkansas-Fort Smith, Fort Smith, Arkansas, USA
| | - Mohammad A Halim
- Department of Physical Sciences, University of Arkansas-Fort Smith, Fort Smith, Arkansas, USA
| |
Collapse
|
12
|
Lei X, He Q, Li Z, Zou Q, Xu P, Yu H, Ding Y, Zhu W. Cancer stem cells in colorectal cancer and the association with chemotherapy resistance. Med Oncol 2021; 38:43. [PMID: 33738588 DOI: 10.1007/s12032-021-01488-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 03/01/2021] [Indexed: 12/13/2022]
Abstract
The incidence and mortality of colorectal cancer (CRC) have always been among the highest in the world, although the diagnosis and treatment are becoming more and more advanced. At present, the main reason is that patients have acquired drug resistance after long-term conventional drug treatment. An increasing number of evidences confirm the existence of cancer stem cells (CSCs), which are a group of special cells in cancer, only a small part of cancer cells. These special cell populations are not eliminated by chemotherapeutic drugs and result in tumor recurrence and metastasis after drug treatment. CSCs have the ability of self-renewal and multidirectional differentiation, which is associated with the occurrence and development of cancer. CSCs can be screened and identified by related surface markers. In this paper, the characteristic surface markers of CSCs in CRC and the related mechanism of drug resistance will be discussed in detail. A better understanding of the mechanism of CSCs resistance to chemotherapy may lead to better targeted therapy.
Collapse
Affiliation(s)
- Xue Lei
- Department of Pathology, Guangdong Medical University, No.1 Xincheng Road, Dongguan, 523808, Guangdong Province, China
| | - Qinglian He
- Department of Pathology, Guangdong Medical University, No.1 Xincheng Road, Dongguan, 523808, Guangdong Province, China
| | - Ziqi Li
- Department of Pathology, Guangdong Medical University, No.1 Xincheng Road, Dongguan, 523808, Guangdong Province, China
| | - Qian Zou
- Department of Pathology, Guangdong Medical University, No.1 Xincheng Road, Dongguan, 523808, Guangdong Province, China
| | - Pingrong Xu
- Department of Pathology, Guangdong Medical University, No.1 Xincheng Road, Dongguan, 523808, Guangdong Province, China
| | - Haibing Yu
- School of Public Health, Guangdong Medical University, Dongguan, 523808, Guangdong Province, China
| | - Yuanlin Ding
- School of Public Health, Guangdong Medical University, Dongguan, 523808, Guangdong Province, China
| | - Wei Zhu
- Department of Pathology, Guangdong Medical University, No.1 Xincheng Road, Dongguan, 523808, Guangdong Province, China.
| |
Collapse
|
13
|
Choi CC, Ford RC. ATP binding cassette importers in eukaryotic organisms. Biol Rev Camb Philos Soc 2021; 96:1318-1330. [PMID: 33655617 DOI: 10.1111/brv.12702] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 02/21/2021] [Accepted: 02/23/2021] [Indexed: 11/28/2022]
Abstract
ATP-binding cassette (ABC) transporters are ubiquitous across all realms of life. Dogma suggests that bacterial ABC transporters include both importers and exporters, whilst eukaryotic members of this family are solely exporters, implying that ABC import function was lost during evolution. This view is being challenged, for example energy-coupling factor (ECF)-type ABC importers appear to fulfil important roles in both algae and plants where they form the ABCI sub-family. Herein we discuss whether bacterial Type I and Type II ABC importers also made the transition into extant eukaryotes. Various studies suggest that Type I importers exist in algae and the liverwort family of primitive non-vascular plants, but not in higher plants. The existence of eukaryotic Type II importers is also supported: a transmembrane protein homologous to vitamin B12 import system transmembrane protein (BtuC), hemin transport system transmembrane protein (HmuU) and high-affinity zinc uptake system membrane protein (ZnuB) is present in the Cyanophora paradoxa genome. This protein has homologs within the genomes of red algae. Furthermore, its candidate nucleotide-binding domain (NBD) shows closest similarity to other bacterial Type II importer NBDs such as BtuD. Functional studies suggest that Type I importers have roles in maintaining sulphate levels in the chloroplast, whilst Type II importers probably act as importers of Mn2+ or Zn2+ , as inferred by comparisons with bacterial homologs. Possible explanations for the presence of these transporters in simple plants, but not in other eukaryotic organisms, are considered. In order to utilise the existing nomenclature for eukaryotic ABC proteins, we propose that eukaryotic Type I and II importers be classified as ABCJ and ABCK transporters, respectively.
Collapse
Affiliation(s)
- Cheri C Choi
- Faculty of Biology Medicine and Health, School of Biological Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PL, U.K.,Department of Biology, University of York, York, YO10 5DD, U.K
| | - Robert C Ford
- Faculty of Biology Medicine and Health, School of Biological Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PL, U.K
| |
Collapse
|
14
|
Millan CR, Francis M, Khandelwal NK, Thompson VF, Thaker TM, Tomasiak TM. A Conserved Motif in Intracellular Loop 1 Stabilizes the Outward-Facing Conformation of TmrAB. J Mol Biol 2021; 433:166834. [PMID: 33524413 DOI: 10.1016/j.jmb.2021.166834] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 01/14/2021] [Accepted: 01/15/2021] [Indexed: 02/05/2023]
Abstract
The ATP binding cassette (ABC) family of transporters moves small molecules (lipids, sugars, peptides, drugs, nutrients) across membranes in nearly all organisms. Transport activity requires conformational switching between inward-facing and outward-facing states driven by ATP-dependent dimerization of two nucleotide binding domains (NBDs). The mechanism that connects ATP binding and hydrolysis in the NBDs to conformational changes in a substrate binding site in the transmembrane domains (TMDs) is currently an outstanding question. Here we use sequence coevolution analyses together with biochemical characterization to investigate the role of a highly conserved region in intracellular loop 1 we define as the GRD motif in coordinating domain rearrangements in the heterodimeric peptide exporter from Thermus thermophilus, TmrAB. Mutations in the GRD motif alter ATPase activity as well as transport. Disulfide crosslinking, evolutionary trace, and evolutionary coupling analysis reveal that these effects are likely due to the destabilization of a network in which the GRD motif in TmrA bridges residues of the Q-loop, X-loop, and ABC motif in the NBDs to residues in the TmrAB peptide substrate binding site, thus providing an avenue for conformational coupling. We further find that disruption of this network in TmrA versus TmrB has different functional consequences, hinting at an intrinsic asymmetry in heterodimeric ABC transporters extending beyond that of the NBDs. These results support a mechanism in which the GRD motifs help coordinate a transition to an outward open conformation, and each half of the transporter likely plays a different role in the conformational cycle of TmrAB.
Collapse
Affiliation(s)
- Cinthia R Millan
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, USA.
| | - Martina Francis
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, USA.
| | | | - Valery F Thompson
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, USA.
| | - Tarjani M Thaker
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, USA.
| | - Thomas M Tomasiak
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, USA.
| |
Collapse
|
15
|
Seelig A. P-Glycoprotein: One Mechanism, Many Tasks and the Consequences for Pharmacotherapy of Cancers. Front Oncol 2020; 10:576559. [PMID: 33194688 PMCID: PMC7649427 DOI: 10.3389/fonc.2020.576559] [Citation(s) in RCA: 98] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 08/31/2020] [Indexed: 12/31/2022] Open
Abstract
P-glycoprotein or multidrug resistance protein (MDR1) is an adenosine triphosphate (ATP) binding cassette transporter (ABCB1) intensely investigated because it is an obstacle to successful pharmacotherapy of cancers. P-glycoprotein prevents cellular uptake of a large number of structurally and functionally diverse compounds, including most cancer therapeutics and in this way causes multidrug resistance (MDR). To overcome MDR, and thus improve cancer treatment, an understanding of P-glycoprotein inhibition at the molecular level is required. With this goal in mind, we propose rules that predict whether a compound is a modulator, substrate, inhibitor, or inducer of P-glycoprotein. This new set of rules is derived from a quantitative analysis of the drug binding and transport properties of P-glycoprotein. We further discuss the role of P-glycoprotein in immune surveillance and cell metabolism. Finally, the predictive power of the proposed rules is demonstrated with a set of FDA approved drugs which have been repurposed for cancer therapy.
Collapse
Affiliation(s)
- Anna Seelig
- Biozentrum, University of Basel, Basel, Switzerland
| |
Collapse
|
16
|
Goda K, Dönmez-Cakil Y, Tarapcsák S, Szalóki G, Szöllősi D, Parveen Z, Türk D, Szakács G, Chiba P, Stockner T. Human ABCB1 with an ABCB11-like degenerate nucleotide binding site maintains transport activity by avoiding nucleotide occlusion. PLoS Genet 2020; 16:e1009016. [PMID: 33031417 PMCID: PMC7544095 DOI: 10.1371/journal.pgen.1009016] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 07/29/2020] [Indexed: 11/28/2022] Open
Abstract
Several ABC exporters carry a degenerate nucleotide binding site (NBS) that is unable to hydrolyze ATP at a rate sufficient for sustaining transport activity. A hallmark of a degenerate NBS is the lack of the catalytic glutamate in the Walker B motif in the nucleotide binding domain (NBD). The multidrug resistance transporter ABCB1 (P-glycoprotein) has two canonical NBSs, and mutation of the catalytic glutamate E556 in NBS1 renders ABCB1 transport-incompetent. In contrast, the closely related bile salt export pump ABCB11 (BSEP), which shares 49% sequence identity with ABCB1, naturally contains a methionine in place of the catalytic glutamate. The NBD-NBD interfaces of ABCB1 and ABCB11 differ only in four residues, all within NBS1. Mutation of the catalytic glutamate in ABCB1 results in the occlusion of ATP in NBS1, leading to the arrest of the transport cycle. Here we show that despite the catalytic glutamate mutation (E556M), ABCB1 regains its ATP-dependent transport activity, when three additional diverging residues are also replaced. Molecular dynamics simulations revealed that the rescue of ATPase activity is due to the modified geometry of NBS1, resulting in a weaker interaction with ATP, which allows the quadruple mutant to evade the conformationally locked pre-hydrolytic state to proceed to ATP-driven transport. In summary, we show that ABCB1 can be transformed into an active transporter with only one functional catalytic site by preventing the formation of the ATP-locked pre-hydrolytic state in the non-canonical site. ABC transporters are one of the largest membrane protein superfamilies, present in all organisms from archaea to humans. They transport a wide range of molecules including amino acids, sugars, vitamins, nucleotides, peptides, lipids, metabolites, antibiotics, and xenobiotics. ABC transporters energize substrate transport by hydrolyzing ATP in two symmetrically arranged nucleotide binding sites (NBSs). The human multidrug resistance transporter ABCB1 has two active NBSs, and it is generally believed that integrity and cooperation of both sites are needed for transport. Several human ABC transporters, such as the bile salt transporter ABCB11, have one degenerate NBS, which has significantly reduced ATPase activity. Interestingly, unilateral mutations affecting one of the two NBSs completely abolish the function of symmetrical ABC transporters. Here we engineered an ABCB1 variant with a degenerate, ABCB11-like NBS1, which can nevertheless transport substrates. Our results indicate that ABCB1 can mediate active transport with a single active site, questioning the validity of models assuming strictly alternating catalysis.
Collapse
Affiliation(s)
- Katalin Goda
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem tér, Debrecen, Hungary
| | - Yaprak Dönmez-Cakil
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Waehringerstrasse, Vienna, Austria
- Department of Histology and Embryology, Faculty of Medicine, Maltepe University, Maltepe, Istanbul, Turkey
| | - Szabolcs Tarapcsák
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem tér, Debrecen, Hungary
- Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, Egyetem tér, Debrecen, Hungary
| | - Gábor Szalóki
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem tér, Debrecen, Hungary
| | - Dániel Szöllősi
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Waehringerstrasse, Vienna, Austria
| | - Zahida Parveen
- Institute of Medical Chemistry, Center for Pathobiochemistry and Genetics, Medical University of Vienna, Waehringerstrasse, Vienna, Austria
- Department of Biochemistry, Abdul Wali Khan University Mardan, Khyber Pakhtunkhwa, Pakistan
| | - Dóra Türk
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar Tudósok körútja, Budapest, Hungary
| | - Gergely Szakács
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar Tudósok körútja, Budapest, Hungary
- Institute of Cancer Research, Medical University of Vienna, Borschkegasse, Vienna, Austria
| | - Peter Chiba
- Institute of Medical Chemistry, Center for Pathobiochemistry and Genetics, Medical University of Vienna, Waehringerstrasse, Vienna, Austria
- * E-mail: (PC); (TS)
| | - Thomas Stockner
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Waehringerstrasse, Vienna, Austria
- * E-mail: (PC); (TS)
| |
Collapse
|
17
|
Carey Hulyer AR, Briggs DA, O'Mara ML, Kerr ID, Harmer JR, Callaghan R. Cross-linking, DEER-spectroscopy and molecular dynamics confirm the inward facing state of P-glycoprotein in a lipid membrane. J Struct Biol 2020; 211:107513. [PMID: 32339763 DOI: 10.1016/j.jsb.2020.107513] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 04/09/2020] [Accepted: 04/23/2020] [Indexed: 02/07/2023]
Abstract
The drug efflux pump P-glycoprotein (P-gp) displays a complex transport mechanism involving multiple drug binding sites and two centres for nucleotide hydrolysis. Elucidating the molecular mechanism of transport remains elusive and the availability of P-gp structures in distinct natural and ligand trapped conformations will accelerate our understanding. The present investigation sought to provide biochemical data to validate specific features of these structures; with particular focus on the transmembrane domain that provides the transport conduit. Hence our focus was on transmembrane helices six and twelve (TM6/TM12), which are believed to participate in drug binding, as they line the central transport conduit and provide a direct link to the catalytic centres. A series of P-gp mutants were generated with a single cysteine in both TM6 and TM12 to facilitate measurement of inter-helical distances using cross-linking and DEER strategies. Experimental results were compared to published structures per se and those refined by MD simulations. This analysis revealed that the refined inward-facing murine structure (4M1M) of P-gp provides a good representation of the proximity, topography and relative motions of TM6 and TM12 in reconstituted human P-gp.
Collapse
Affiliation(s)
- Alex R Carey Hulyer
- Research School of Biology, and the Medical School, Australian National University, Canberra, ACT 2601, Australia
| | - Deborah A Briggs
- Centre for Biochemistry and Cell Biology, School of Biomedical Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, UK
| | - Megan L O'Mara
- Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Ian D Kerr
- Centre for Biochemistry and Cell Biology, School of Biomedical Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, UK
| | - Jeffrey R Harmer
- The Centre for Advanced Imaging, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Richard Callaghan
- Research School of Biology, and the Medical School, Australian National University, Canberra, ACT 2601, Australia.
| |
Collapse
|
18
|
Ethnogeographic and inter-individual variability of human ABC transporters. Hum Genet 2020; 139:623-646. [PMID: 32206879 PMCID: PMC7170817 DOI: 10.1007/s00439-020-02150-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Accepted: 03/16/2020] [Indexed: 12/19/2022]
Abstract
ATP-binding cassette (ABC) transporters constitute a superfamily of 48 structurally similar membrane transporters that mediate the ATP-dependent cellular export of a plethora of endogenous and xenobiotic substances. Importantly, genetic variants in ABC genes that affect gene function have clinically important effects on drug disposition and can be predictors of the risk of adverse drug reactions and efficacy of chemotherapeutics, calcium channel blockers, and protease inhibitors. Furthermore, loss-of-function of ABC transporters is associated with a variety of congenital disorders. Despite their clinical importance, information about the frequencies and global distribution of functionally relevant ABC variants is limited and little is known about the overall genetic complexity of this important gene family. Here, we systematically mapped the genetic landscape of the entire human ABC superfamily using Next-Generation Sequencing data from 138,632 individuals across seven major populations. Overall, we identified 62,793 exonic variants, 98.5% of which were rare. By integrating five computational prediction algorithms with structural mapping approaches using experimentally determined crystal structures, we found that the functional ABC variability is extensive and highly population-specific. Every individual harbored between 9.3 and 13.9 deleterious ABC variants, 76% of which were found only in a single population. Carrier rates of pathogenic variants in ABC transporter genes associated with autosomal recessive congenital diseases, such as cystic fibrosis or pseudoxanthoma elasticum, closely mirrored the corresponding population-specific disease prevalence, thus providing a novel resource for rare disease epidemiology. Combined, we provide the most comprehensive, systematic, and consolidated overview of ethnogeographic ABC transporter variability with important implications for personalized medicine, clinical genetics, and precision public health.
Collapse
|
19
|
Schiltz CJ, Adams MC, Chappie JS. The full-length structure of Thermus scotoductus OLD defines the ATP hydrolysis properties and catalytic mechanism of Class 1 OLD family nucleases. Nucleic Acids Res 2020; 48:2762-2776. [PMID: 32009148 PMCID: PMC7049728 DOI: 10.1093/nar/gkaa059] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 12/28/2019] [Accepted: 01/20/2020] [Indexed: 12/15/2022] Open
Abstract
OLD family nucleases contain an N-terminal ATPase domain and a C-terminal Toprim domain. Homologs segregate into two classes based on primary sequence length and the presence/absence of a unique UvrD/PcrA/Rep-like helicase gene immediately downstream in the genome. Although we previously defined the catalytic machinery controlling Class 2 nuclease cleavage, degenerate conservation of the C-termini between classes precludes pinpointing the analogous residues in Class 1 enzymes by sequence alignment alone. Our Class 2 structures also provide no information on ATPase domain architecture and ATP hydrolysis. Here we present the full-length structure of the Class 1 OLD nuclease from Thermus scotoductus (Ts) at 2.20 Å resolution, which reveals a dimerization domain inserted into an N-terminal ABC ATPase fold and a C-terminal Toprim domain. Structural homology with genome maintenance proteins identifies conserved residues responsible for Ts OLD ATPase activity. Ts OLD lacks the C-terminal helical domain present in Class 2 OLD homologs yet preserves the spatial organization of the nuclease active site, arguing that OLD proteins use a conserved catalytic mechanism for DNA cleavage. We also demonstrate that mutants perturbing ATP hydrolysis or DNA cleavage in vitro impair P2 OLD-mediated killing of recBC-Escherichia coli hosts, indicating that both the ATPase and nuclease activities are required for OLD function in vivo.
Collapse
Affiliation(s)
- Carl J Schiltz
- Department of Molecular Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Myfanwy C Adams
- Department of Molecular Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Joshua S Chappie
- Department of Molecular Medicine, Cornell University, Ithaca, NY 14853, USA
| |
Collapse
|
20
|
van Veen HW, Singh H, Agboh K, Fagg LA, Guo D, Swain B, de Kruijf RF, Guffick C. Energy coupling in ABC exporters. Res Microbiol 2019; 170:392-398. [PMID: 31442612 DOI: 10.1016/j.resmic.2019.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 07/27/2019] [Accepted: 08/12/2019] [Indexed: 11/19/2022]
Abstract
Multidrug transporters are important and interesting molecular machines that extrude a wide variety of cytotoxic drugs from target cells. This review summarizes novel insights in the energetics and mechanisms of bacterial ATP-binding cassette multidrug transporters as well as recent advances connecting multidrug transport to ion and lipid translocation processes in other membrane proteins.
Collapse
Affiliation(s)
- Hendrik W van Veen
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK.
| | - Himansha Singh
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK
| | - Kelvin Agboh
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK
| | - Lisa A Fagg
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK
| | - Dawei Guo
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK
| | - Brendan Swain
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK
| | - Robbin F de Kruijf
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK
| | - Charlotte Guffick
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK
| |
Collapse
|
21
|
Thonghin N, Collins RF, Barbieri A, Shafi T, Siebert A, Ford RC. Novel features in the structure of P-glycoprotein (ABCB1) in the post-hydrolytic state as determined at 7.9 Å resolution. BMC STRUCTURAL BIOLOGY 2018; 18:17. [PMID: 30545335 PMCID: PMC6293506 DOI: 10.1186/s12900-018-0098-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 12/04/2018] [Indexed: 12/15/2022]
Abstract
BACKGROUND P-glycoprotein (ABCB1) is an ATP-binding cassette transporter that plays an important role in the clearance of drugs and xenobiotics and is associated with multi-drug resistance in cancer. Although several P-glycoprotein structures are available, these are either at low resolution, or represent mutated and/or quiescent states of the protein. RESULTS In the post-hydrolytic state the structure of the wild-type protein has been resolved at about 8 Å resolution. The cytosolic nucleotide-binding domains (NBDs) are separated but ADP remains bound, especially at the first NBD. Gaps in the transmembrane domains (TMDs) that connect to an inner hydrophilic cavity are filled by density emerging from the annular detergent micelle. The NBD-TMD linker is partly resolved, being located between the NBDs and close to the Signature regions involved in cooperative NBD dimerization. This, and the gap-filling detergent suggest steric impediment to NBD dimerization in the post-hydrolytic state. Two central regions of density lie in two predicted drug-binding sites, implying that the protein may adventitiously bind hydrophobic substances even in the post-hydrolytic state. The previously unresolved N-terminal extension was observed, and the data suggests these 30 residues interact with the headgroup region of the lipid bilayer. CONCLUSION The structural data imply that (i) a low basal ATPase activity is ensured by steric blockers of NBD dimerization and (ii) allocrite access to the central cavity may be structurally linked to NBD dimerization, giving insights into the mechanism of drug-stimulation of P-glycoprotein activity.
Collapse
Affiliation(s)
- Nopnithi Thonghin
- School of Biology, Faculty of Biology Medicine and Health, Michael Smith Building, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Richard F Collins
- School of Biology, Faculty of Biology Medicine and Health, Michael Smith Building, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Alessandro Barbieri
- School of Biology, Faculty of Biology Medicine and Health, Michael Smith Building, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Talha Shafi
- School of Biology, Faculty of Biology Medicine and Health, Michael Smith Building, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Alistair Siebert
- eBIC, Diamond Light Source Ltd, Diamond House, Harwell Science & Innovation Campus, Oxfordshire, Didcot, OX11 0DE, UK
| | - Robert C Ford
- School of Biology, Faculty of Biology Medicine and Health, Michael Smith Building, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
| |
Collapse
|
22
|
Rahman SJ, Kaur P. Conformational changes in a multidrug resistance ABC transporter DrrAB: Fluorescence-based approaches to study substrate binding. Arch Biochem Biophys 2018; 658:31-45. [PMID: 30243711 DOI: 10.1016/j.abb.2018.09.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 08/30/2018] [Accepted: 09/19/2018] [Indexed: 01/12/2023]
Abstract
Bacterial multidrug transporter DrrAB exhibits overlapping substrate specificity with mammalian P-glycoprotein. DrrA hydrolyzes ATP, and the energy is transduced to carrier DrrB resulting in export of drugs. Previous studies suggested that DrrB contains a large and flexible drug-binding pocket made of aromatic residues contributed by several transmembrane helices with different drugs binding to both specific and shared residues in this pocket. However, direct binding of drugs to DrrAB or the mechanism of substrate-induced conformational changes between DrrA and DrrB has so far not been investigated. We used two fluorescence-based approaches to determine substrate binding to purified DrrAB. Our analysis shows that DrrB binds drugs with variable affinities and contains multiple drug binding sites. This work also provides evidence for two asymmetric nucleotide binding sites in DrrA with strikingly different binding affinities. Using targeted fluorescence labeling, we provide clear evidence of long-range conformational changes occurring between DrrA and DrrB. It is proposed that the transduction pathway from the nucleotide-binding DrrA subunit to the substrate binding DrrB subunit includes Q-loop and CREEM motifs in DrrA and EAA-like motif in DrrB. This study lays a solid groundwork for examining roles of various conserved regions of DrrA and DrrB in transduction of conformational changes.
Collapse
Affiliation(s)
- Sadia J Rahman
- Department of Biology, Georgia State University, Atlanta, GA, 30303, United States
| | - Parjit Kaur
- Department of Biology, Georgia State University, Atlanta, GA, 30303, United States.
| |
Collapse
|
23
|
Kim Y, Chen J. Molecular structure of human P-glycoprotein in the ATP-bound, outward-facing conformation. Science 2018; 359:915-919. [PMID: 29371429 DOI: 10.1126/science.aar7389] [Citation(s) in RCA: 313] [Impact Index Per Article: 52.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 01/16/2018] [Indexed: 12/28/2022]
Abstract
The multidrug transporter permeability (P)-glycoprotein is an adenosine triphosphate (ATP)-binding cassette exporter responsible for clinical resistance to chemotherapy. P-glycoprotein extrudes toxic molecules and drugs from cells through ATP-powered conformational changes. Despite decades of effort, only the structures of the inward-facing conformation of P-glycoprotein are available. Here we present the structure of human P-glycoprotein in the outward-facing conformation, determined by cryo-electron microscopy at 3.4-angstrom resolution. The two nucleotide-binding domains form a closed dimer occluding two ATP molecules. The drug-binding cavity observed in the inward-facing structures is reorientated toward the extracellular space and compressed to preclude substrate binding. This observation indicates that ATP binding, not hydrolysis, promotes substrate release. The structure evokes a model in which the dynamic nature of P-glycoprotein enables translocation of a large variety of substrates.
Collapse
Affiliation(s)
- Youngjin Kim
- Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Jue Chen
- Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
| |
Collapse
|
24
|
Szöllősi D, Rose-Sperling D, Hellmich UA, Stockner T. Comparison of mechanistic transport cycle models of ABC exporters. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:818-832. [PMID: 29097275 PMCID: PMC7610611 DOI: 10.1016/j.bbamem.2017.10.028] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 10/23/2017] [Accepted: 10/25/2017] [Indexed: 12/25/2022]
Abstract
ABC (ATP binding cassette) transporters, ubiquitous in all kingdoms of life, carry out essential substrate transport reactions across cell membranes. Their transmembrane domains bind and translocate substrates and are connected to a pair of nucleotide binding domains, which bind and hydrolyze ATP to energize import or export of substrates. Over four decades of investigations into ABC transporters have revealed numerous details from atomic-level structural insights to their functional and physiological roles. Despite all these advances, a comprehensive understanding of the mechanistic principles of ABC transporter function remains elusive. The human multidrug resistance transporter ABCB1, also referred to as P-glycoprotein (P-gp), is one of the most intensively studied ABC exporters. Using ABCB1 as the reference point, we aim to compare the dominating mechanistic models of substrate transport and ATP hydrolysis for ABC exporters and to highlight the experimental and computational evidence in their support. In particular, we point out in silico studies that enhance and complement available biochemical data. “This article is part of a Special Issue entitled: Beyond the Structure Function Horizon of Membrane Proteins edited by Ute Hellmich, Rupak Doshi and Benjamin McIlwain.”
Collapse
Affiliation(s)
- Dániel Szöllősi
- Medical University of Vienna, Institute of Pharmacology, Waehringerstr. 13A, Vienna 1090, Austria
| | - Dania Rose-Sperling
- Johannes Gutenberg-University, Department of Pharmacy and Biochemistry, Johann-Joachim-Becher-Weg 30, Mainz 55128, Germany; Centre for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt, Max von Laue-Str. 9, 60438 Frankfurt am Main, Germany
| | - Ute A Hellmich
- Johannes Gutenberg-University, Department of Pharmacy and Biochemistry, Johann-Joachim-Becher-Weg 30, Mainz 55128, Germany; Centre for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt, Max von Laue-Str. 9, 60438 Frankfurt am Main, Germany
| | - Thomas Stockner
- Medical University of Vienna, Institute of Pharmacology, Waehringerstr. 13A, Vienna 1090, Austria.
| |
Collapse
|
25
|
Loo TW, Clarke DM. A short cross-linker activates human P-glycoprotein missing a catalytic carboxylate. Biochem Pharmacol 2017; 145:27-33. [PMID: 28837794 DOI: 10.1016/j.bcp.2017.08.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 08/18/2017] [Indexed: 11/17/2022]
Abstract
P-glycoprotein (P-gp) is an ATP-dependent drug pump that protects us from toxic agents and confers multidrug resistance. It has a tweezer-like structure with each arm consisting of a transmembrane domain (TMD) and a nucleotide-binding domain (NBD). Drug substrates bind to sites within the TMDs to activate ATPase activity by promoting a tweezer-like closing of the gap between the NBDs. The catalytic carboxylates may be critical for NBD movements because the E556Q(NBD1) or E1201Q(NBD2) mutation inhibited drug-stimulated ATPase activity. If the catalytic carboxylates were components of the mechanism to bring the NBDs together, then we predicted that insertion of a flexible cross-linker between the arms would increase ATPase activity of the mutants. We found that cross-linking (between L175C(TMD1) and N820C(TMD2)) with a short flexible cross-linker (7.8Å maximum) restored high levels of drug-stimulated ATPase activity of the E556Q or E1201Q mutants. Cross-linking with a longer cross-linker (22Å maximum) however, did not restore activity. Cross-linking could not rescue all ATPase deficient mutants. For example, cross-linking L175C/N820C with short or long cross-linkers did not activate the H-loop mutants H587A or H1232A or the Walker A K433M or K1076M mutants. The results suggest that the E556 and E1201 catalytic carboxylates are part of a spring-like mechanism that is required to facilitate movements between the open and closed conformations of P-gp during ATP hydrolysis.
Collapse
Affiliation(s)
- Tip W Loo
- Department of Medicine and Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - David M Clarke
- Department of Medicine and Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
| |
Collapse
|
26
|
Ferreira RJ, Bonito CA, Ferreira MJU, dos Santos DJ. About P-glycoprotein: a new drugable domain is emerging from structural data. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2017. [DOI: 10.1002/wcms.1316] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Ricardo J. Ferreira
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy; Universidade de Lisboa; Lisboa Portugal
| | - Cátia A. Bonito
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy; Universidade de Lisboa; Lisboa Portugal
- LAQV@REQUIMTE/Department of Chemistry and Biochemistry, Faculty of Sciences; University of Porto; Porto Portugal
| | - Maria José U. Ferreira
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy; Universidade de Lisboa; Lisboa Portugal
| | - Daniel J.V.A. dos Santos
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy; Universidade de Lisboa; Lisboa Portugal
- LAQV@REQUIMTE/Department of Chemistry and Biochemistry, Faculty of Sciences; University of Porto; Porto Portugal
| |
Collapse
|
27
|
Hürlimann LM, Hohl M, Seeger MA. Split tasks of asymmetric nucleotide-binding sites in the heterodimeric ABC exporter EfrCD. FEBS J 2017; 284:1672-1687. [PMID: 28417533 DOI: 10.1111/febs.14065] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 03/21/2017] [Accepted: 03/22/2017] [Indexed: 11/30/2022]
Abstract
Many heterodimeric ATP-binding cassette (ABC) exporters evolved asymmetric ATP-binding sites containing a degenerate site incapable of ATP hydrolysis due to noncanonical substitutions in conserved sequence motifs. Recent studies revealed that nucleotide binding to the degenerate site stabilizes contacts between the nucleotide-binding domains (NBDs) of the inward-facing transporter and regulates ATP hydrolysis at the consensus site via allosteric coupling mediated by the D-loops. However, it is unclear whether nucleotide binding to the degenerate site is strictly required for substrate transport. In this study, we examined the functional consequences of a systematic set of mutations introduced at the degenerate and consensus site of the multidrug efflux pump EfrCD of Enterococcus faecalis. Mutating motifs which differ among the two ATP-binding sites (Walker B, switch loop, and ABC signature) or which are involved in interdomain communication (D-loop and Q-loop) led to asymmetric results in the functional assays and were better tolerated at the degenerate site. This highlights the importance of the degenerate site to allosterically regulate the events at the consensus site. Mutating invariant motifs involved in ATP binding and NBD closure (A-loop and Walker A) resulted in equally reduced transport activities, regardless at which ATP-binding site they were introduced. In contrast to previously investigated heterodimeric ABC exporters, mutation of the degenerate site Walker A lysine completely inactivated ATPase activity and substrate transport, indicating that ATP binding to the degenerate site is essential for EfrCD. This study provides novel insights into the split tasks of asymmetric ATP-binding sites of heterodimeric ABC exporters.
Collapse
Affiliation(s)
- Lea M Hürlimann
- Institute of Medical Microbiology, University of Zurich, Switzerland
| | - Michael Hohl
- Institute of Medical Microbiology, University of Zurich, Switzerland
| | - Markus A Seeger
- Institute of Medical Microbiology, University of Zurich, Switzerland
| |
Collapse
|
28
|
Lewinson O, Livnat-Levanon N. Mechanism of Action of ABC Importers: Conservation, Divergence, and Physiological Adaptations. J Mol Biol 2017; 429:606-619. [PMID: 28104364 DOI: 10.1016/j.jmb.2017.01.010] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 01/03/2017] [Accepted: 01/04/2017] [Indexed: 01/08/2023]
Abstract
The past decade has seen a remarkable surge in structural characterization of ATP binding cassette (ABC) transporters, which have spurred a more focused functional analysis of these elaborate molecular machines. As a result, it has become increasingly apparent that there is a substantial degree of mechanistic variation between ABC transporters that function as importers, which correlates with their physiological roles. Here, we summarize recent advances in ABC importers' structure-function studies and provide an explanation as to the origin of the different mechanisms of action.
Collapse
Affiliation(s)
- Oded Lewinson
- Department of Biochemistry, The Bruce and Ruth Rappaport Faculty of Medicine, The Technion-Israel Institute of Technology, 31096 Haifa, Israel.
| | - Nurit Livnat-Levanon
- Department of Biochemistry, The Bruce and Ruth Rappaport Faculty of Medicine, The Technion-Israel Institute of Technology, 31096 Haifa, Israel
| |
Collapse
|
29
|
Loo TW, Clarke DM. Attachment of a 'molecular spring' restores drug-stimulated ATPase activity to P-glycoprotein lacking both Q loop glutamines. Biochem Biophys Res Commun 2016; 483:366-370. [PMID: 28025146 DOI: 10.1016/j.bbrc.2016.12.137] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 12/21/2016] [Indexed: 01/28/2023]
Abstract
P-glycoprotein (P-gp) is an ABC (ATP-Binding Cassette) drug pump that is clinically important because it confers multidrug resistance. Drugs bind at the interface between the transmembrane domains to activate ATPase activity at the two nucleotide-binding domains (NBDs). Drug transport involves ATP-dependent conformational changes between inward- (open, NBDs far apart) and outward-facing (closed, NBDs close together) conformations. Recently, it was reported that the conserved glutamines residues (Gln475 in NBD1 and Gln1118 in NBD2) in the Q loops of P-gp when mutated to alanine completely inhibited the drug-stimulated ATPase activity. It is unknown why the glutamine residues (Gln475 and Gln1118) in the Q loops of the NBDs of P-gp are required for drug-stimulated ATPase activity. Here we show that introduction of these mutations into the L175C/N820C mutant (L175C/N820C/Q475A/Q1118A) also abolished drug-stimulated ATPase activity. The ATPase activity was restored however, when the L175C/N820C/Q475A/Q1118A mutant was cross-linked with a flexible disulfide cross-linker. These results suggest that both Q-loop glutamines are not required for ATP hydrolysis and they might function as part of a spring-like mechanism in facilitating the open (inactive) to closed (active) conformational change during ATP hydrolysis. The molecular spring-like action of the Q-loop glutamines during drug-stimulated ATPase activity is likely mimicked by the attachment of the flexible cross-linker.
Collapse
Affiliation(s)
- Tip W Loo
- Department of Medicine and Department of Biochemistry, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - David M Clarke
- Department of Medicine and Department of Biochemistry, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.
| |
Collapse
|
30
|
ATP-dependent substrate transport by the ABC transporter MsbA is proton-coupled. Nat Commun 2016; 7:12387. [PMID: 27499013 PMCID: PMC4979069 DOI: 10.1038/ncomms12387] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 06/22/2016] [Indexed: 01/11/2023] Open
Abstract
ATP-binding cassette transporters mediate the transbilayer movement of a vast number of substrates in or out of cells in organisms ranging from bacteria to humans. Current alternating access models for ABC exporters including the multidrug and Lipid A transporter MsbA from Escherichia coli suggest a role for nucleotide as the fundamental source of free energy. These models involve cycling between conformations with inward- and outward-facing substrate-binding sites in response to engagement and hydrolysis of ATP at the nucleotide-binding domains. Here we report that MsbA also utilizes another major energy currency in the cell by coupling substrate transport to a transmembrane electrochemical proton gradient. The dependence of ATP-dependent transport on proton coupling, and the stimulation of MsbA-ATPase by the chemical proton gradient highlight the functional integration of both forms of metabolic energy. These findings introduce ion coupling as a new parameter in the mechanism of this homodimeric ABC transporter. ABC exporters mediate the translocation of cytotoxic compounds to the cell exterior via ATP hydrolysis. Here, the authors show that the bacterial transporter MsbA requires additional energy from the transmembrane electrochemical proton gradient to facilitate drug transport.
Collapse
|
31
|
Loo TW, Clarke DM. Drugs Modulate Interactions between the First Nucleotide-Binding Domain and the Fourth Cytoplasmic Loop of Human P-Glycoprotein. Biochemistry 2016; 55:2817-20. [DOI: 10.1021/acs.biochem.6b00233] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tip W. Loo
- Departments
of Medicine and
Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - David M. Clarke
- Departments
of Medicine and
Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| |
Collapse
|
32
|
A single active catalytic site is sufficient to promote transport in P-glycoprotein. Sci Rep 2016; 6:24810. [PMID: 27117502 PMCID: PMC4846820 DOI: 10.1038/srep24810] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 04/05/2016] [Indexed: 11/23/2022] Open
Abstract
P-glycoprotein (Pgp) is an ABC transporter responsible for the ATP-dependent efflux of chemotherapeutic compounds from multidrug resistant cancer cells. Better understanding of the molecular mechanism of Pgp-mediated transport could promote rational drug design to circumvent multidrug resistance. By measuring drug binding affinity and reactivity to a conformation-sensitive antibody we show here that nucleotide binding drives Pgp from a high to a low substrate-affinity state and this switch coincides with the flip from the inward- to the outward-facing conformation. Furthermore, the outward-facing conformation survives ATP hydrolysis: the post-hydrolytic complex is stabilized by vanadate, and the slow recovery from this state requires two functional catalytic sites. The catalytically inactive double Walker A mutant is stabilized in a high substrate affinity inward-open conformation, but mutants with one intact catalytic center preserve their ability to hydrolyze ATP and to promote drug transport, suggesting that the two catalytic sites are randomly recruited for ATP hydrolysis.
Collapse
|
33
|
Hellmich UA, Mönkemeyer L, Velamakanni S, van Veen HW, Glaubitz C. Effects of nucleotide binding to LmrA: A combined MAS-NMR and solution NMR study. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:3158-65. [PMID: 26449340 DOI: 10.1016/j.bbamem.2015.10.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 09/25/2015] [Accepted: 10/01/2015] [Indexed: 11/26/2022]
Abstract
ABC transporters are fascinating examples of fine-tuned molecular machines that use the energy from ATP hydrolysis to translocate a multitude of substrates across biological membranes. While structural details have emerged on many members of this large protein superfamily, a number of functional details are still under debate. High resolution structures yield valuable insights into protein function, but it is the combination of structural, functional and dynamic insights that facilitates a complete understanding of the workings of their complex molecular mechanisms. NMR is a technique well-suited to investigate proteins in atomic resolution while taking their dynamic properties into account. It thus nicely complements other structural techniques, such as X-ray crystallography, that have contributed high-resolution data to the architectural understanding of ABC transporters. Here, we describe the heterologous expression of LmrA, an ABC exporter from Lactococcus lactis, in Escherichia coli. This allows for more flexible isotope labeling for nuclear magnetic resonance (NMR) studies and the easy study of LmrA's multidrug resistance phenotype. We use a combination of solid-state magic angle spinning (MAS) on the reconstituted transporter and solution NMR on its isolated nucleotide binding domain to investigate consequences of nucleotide binding to LmrA. We find that nucleotide binding affects the protein globally, but that NMR is also able to pinpoint local dynamic effects to specific residues, such as the Walker A motif's conserved lysine residue.
Collapse
Affiliation(s)
- Ute A Hellmich
- Department of Pharmacy and Biochemistry, Johannes Gutenberg-University Mainz, Germany; Centre for Biomolecular Magnetic Resonance (BMRZ), J.W. Goethe University, Frankfurt, Germany.
| | - Leonie Mönkemeyer
- Centre for Biomolecular Magnetic Resonance (BMRZ), J.W. Goethe University, Frankfurt, Germany; Department of Biophysical Chemistry, J.W. Goethe University, Frankfurt, Germany
| | | | | | - Clemens Glaubitz
- Centre for Biomolecular Magnetic Resonance (BMRZ), J.W. Goethe University, Frankfurt, Germany; Department of Biophysical Chemistry, J.W. Goethe University, Frankfurt, Germany; Cluster of Excellence Macromolecular Complexes Frankfurt, Germany.
| |
Collapse
|
34
|
Egido E, Müller R, Li-Blatter X, Merino G, Seelig A. Predicting Activators and Inhibitors of the Breast Cancer Resistance Protein (ABCG2) and P-Glycoprotein (ABCB1) Based on Mechanistic Considerations. Mol Pharm 2015; 12:4026-37. [DOI: 10.1021/acs.molpharmaceut.5b00463] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Estefanía Egido
- University of Basel, Biozentrum, Klingelbergstrasse 50/70, CH-4056 Basel, Switzerland
- INDEGSAL,
Campus Vegazana s/n, University of Leon, 24071 Leon, Spain
- Department
of Biomedical Sciences—Physiology, Veterinary Faculty, Campus
Vegazana s/n, University of Leon, 24071 Leon, Spain
| | - Rita Müller
- University of Basel, Biozentrum, Klingelbergstrasse 50/70, CH-4056 Basel, Switzerland
| | - Xiaochun Li-Blatter
- University of Basel, Biozentrum, Klingelbergstrasse 50/70, CH-4056 Basel, Switzerland
| | - Gracia Merino
- INDEGSAL,
Campus Vegazana s/n, University of Leon, 24071 Leon, Spain
- Department
of Biomedical Sciences—Physiology, Veterinary Faculty, Campus
Vegazana s/n, University of Leon, 24071 Leon, Spain
| | - Anna Seelig
- University of Basel, Biozentrum, Klingelbergstrasse 50/70, CH-4056 Basel, Switzerland
| |
Collapse
|
35
|
Akkaya BG, Zolnerciks JK, Ritchie TK, Bauer B, Hartz AMS, Sullivan JA, Linton KJ. The multidrug resistance pump ABCB1 is a substrate for the ubiquitin ligase NEDD4-1. Mol Membr Biol 2015; 32:39-45. [PMID: 26006083 DOI: 10.3109/09687688.2015.1023378] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The ATP Binding Cassette transporter ABCB1 can export the neurotoxic peptide β-amyloid from endothelial cells that line the blood-brain barrier (BBB). This has the potential to lower cerebral levels of β-amyloid, but ABCB1 expression in the BBB appears to be progressively reduced in patients with Alzheimer's disease. The surface density of many membrane proteins is regulated by ubiquitination catalyzed by ubiquitin E3 ligases. In brain capillaries of mice challenged with β-amyloid ex vivo, we show that the level of the ubiquitin ligase Nedd4 increases concomitant with reduction in Abcb1. In vitro we show that human ABCB1 is a substrate for human NEDD4-1 ligase. Recombinant ABCB1 was purified from Sf21 insect cells and incubated with recombinant NEDD4-1 purified from Escherichia coli. The treated ABCB1 had reduced mobility on SDS-PAGE, and mass spectrometry identified eight lysine residues, K271, K272, K575, K685, K877, K885, K887 and K1062 that were ubiquitinated by NEDD4-1. Molecular modelling showed that all of the residues are exposed on the surface of the intracellular domains of ABCB1. K877, K885 and K887 in particular, are located in the intracellular loop of transmembrane helix 10 (TMH10) in close proximity, in the tertiary fold, to a putative NEDD4-1 binding site in the intracellular helix extending from TMH12 (PxY motif, residues 996-998). Transient expression of NEDD4-1 in HEK293 Flp-In cells stably expressing ABCB1 was shown to reduce the surface density of the transporter. Together, the data identify this ubiquitin ligase as a potential target for intervention in the pathophysiology of Alzheimer's disease.
Collapse
Affiliation(s)
- Begum G Akkaya
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London , London , UK
| | | | | | | | | | | | | |
Collapse
|
36
|
Loo TW, Clarke DM. The Transmission Interfaces Contribute Asymmetrically to the Assembly and Activity of Human P-glycoprotein. J Biol Chem 2015; 290:16954-63. [PMID: 25987565 PMCID: PMC4505440 DOI: 10.1074/jbc.m115.652602] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Indexed: 11/21/2022] Open
Abstract
P-glycoprotein (P-gp; ABCB1) is an ABC drug pump that protects us from toxic compounds. It is clinically important because it confers multidrug resistance. The homologous halves of P-gp each contain a transmembrane (TM) domain (TMD) with 6 TM segments followed by a nucleotide-binding domain (NBD). The drug- and ATP-binding sites reside at the interface between the TMDs and NBDs, respectively. Each NBD is connected to the TMDs by a transmission interface involving a pair of intracellular loops (ICLs) that form ball-and-socket joints. P-gp is different from CFTR (ABCC7) in that deleting NBD2 causes misprocessing of only P-gp. Therefore, NBD2 might be critical for stabilizing ICLs 2 and 3 that form a tetrahelix bundle at the NBD2 interface. Here we report that the NBD1 and NBD2 transmission interfaces in P-gp are asymmetric. Point mutations to 25 of 60 ICL2/ICL3 residues at the NBD2 transmission interface severely reduced P-gp assembly while changes to the equivalent residues in ICL1/ICL4 at the NBD1 interface had little effect. The hydrophobic nature at the transmission interfaces was also different. Mutation of Phe-1086 or Tyr-1087 to arginine at the NBD2 socket blocked activity or assembly while the equivalent mutations at the NBD1 socket had only modest effects. The results suggest that the NBD transmission interfaces are asymmetric. In contrast to the ICL2/3-NBD2 interface, the ICL1/4-NBD1 transmission interface is more hydrophilic and insensitive to mutations. Therefore the ICL2/3-NBD2 transmission interface forms a precise hydrophobic connection that acts as a linchpin for assembly and trafficking of P-gp.
Collapse
Affiliation(s)
- Tip W Loo
- From the Departments of Medicine and Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - David M Clarke
- From the Departments of Medicine and Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| |
Collapse
|
37
|
Dong Q, Ernst SE, Ostedgaard LS, Shah VS, Ver Heul AR, Welsh MJ, Randak CO. Mutating the Conserved Q-loop Glutamine 1291 Selectively Disrupts Adenylate Kinase-dependent Channel Gating of the ATP-binding Cassette (ABC) Adenylate Kinase Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) and Reduces Channel Function in Primary Human Airway Epithelia. J Biol Chem 2015; 290:14140-53. [PMID: 25887396 PMCID: PMC4447984 DOI: 10.1074/jbc.m114.611616] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Indexed: 11/06/2022] Open
Abstract
The ATP-binding cassette (ABC) transporter cystic fibrosis transmembrane conductance regulator (CFTR) and two other non-membrane-bound ABC proteins, Rad50 and a structural maintenance of chromosome (SMC) protein, exhibit adenylate kinase activity in the presence of physiologic concentrations of ATP and AMP or ADP (ATP + AMP ⇆ 2 ADP). The crystal structure of the nucleotide-binding domain of an SMC protein in complex with the adenylate kinase bisubstrate inhibitor P(1),P(5)-di(adenosine-5') pentaphosphate (Ap5A) suggests that AMP binds to the conserved Q-loop glutamine during the adenylate kinase reaction. Therefore, we hypothesized that mutating the corresponding residue in CFTR, Gln-1291, selectively disrupts adenylate kinase-dependent channel gating at physiologic nucleotide concentrations. We found that substituting Gln-1291 with bulky side-chain amino acids abolished the effects of Ap5A, AMP, and adenosine 5'-monophosphoramidate on CFTR channel function. 8-Azidoadenosine 5'-monophosphate photolabeling of the AMP-binding site and adenylate kinase activity were disrupted in Q1291F CFTR. The Gln-1291 mutations did not alter the potency of ATP at stimulating current or ATP-dependent gating when ATP was the only nucleotide present. However, when physiologic concentrations of ADP and AMP were added, adenylate kinase-deficient Q1291F channels opened significantly less than wild type. Consistent with this result, we found that Q1291F CFTR displayed significantly reduced Cl(-) channel function in well differentiated primary human airway epithelia. These results indicate that a highly conserved residue of an ABC transporter plays an important role in adenylate kinase-dependent CFTR gating. Furthermore, the results suggest that adenylate kinase activity is important for normal CFTR channel function in airway epithelia.
Collapse
Affiliation(s)
- Qian Dong
- From the Stead Family Department of Pediatrics
| | - Sarah E Ernst
- the Department of Internal Medicine, the Howard Hughes Medical Institute, Iowa City, Iowa 52242
| | | | - Viral S Shah
- the Department of Molecular Physiology and Biophysics, and the Medical Scientist Training Program, University of Iowa, Iowa City, Iowa 52242 and
| | | | - Michael J Welsh
- the Department of Internal Medicine, the Howard Hughes Medical Institute, Iowa City, Iowa 52242 the Department of Molecular Physiology and Biophysics, and
| | | |
Collapse
|