1
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Erramilli SK, Dominik PK, Deneka D, Tokarz P, Kim SS, Reddy BG, Skrobek BM, Dalmas O, Perozo E, Kossiakoff AA. Conformation-specific Synthetic Antibodies Discriminate Multiple Functional States of the Ion Channel CorA. J Mol Biol 2023; 435:168192. [PMID: 37394032 PMCID: PMC10529903 DOI: 10.1016/j.jmb.2023.168192] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 06/20/2023] [Accepted: 06/26/2023] [Indexed: 07/04/2023]
Abstract
CorA, the primary magnesium ion channel in prokaryotes and archaea, is a prototypical homopentameric ion channel that undergoes ion-dependent conformational transitions. CorA adopts five-fold symmetric non-conductive states in the presence of high concentrations of Mg2+, and highly asymmetric flexible states in its complete absence. However, the latter were of insufficient resolution to be thoroughly characterized. In order to gain additional insights into the relationship between asymmetry and channel activation, we exploited phage display selection strategies to generate conformation-specific synthetic antibodies (sABs) against CorA in the absence of Mg2+. Two sABs from these selections, C12 and C18, showed different degrees of Mg2+-sensitivity. Through structural, biochemical, and biophysical characterization, we found the sABs are both conformation-specific but probe different features of the channel under open-like conditions. C18 is highly specific to the Mg2+-depleted state of CorA and through negative-stain electron microscopy (ns-EM), we show sAB binding reflects the asymmetric arrangement of CorA protomers in Mg2+-depleted conditions. We used X-ray crystallography to determine a structure at 2.0 Å resolution of sAB C12 bound to the soluble N-terminal regulatory domain of CorA. The structure shows C12 is a competitive inhibitor of regulatory magnesium binding through its interaction with the divalent cation sensing site. We subsequently exploited this relationship to capture and visualize asymmetric CorA states in different [Mg2+] using ns-EM. We additionally utilized these sABs to provide insights into the energy landscape that governs the ion-dependent conformational transitions of CorA.
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Affiliation(s)
- Satchal K Erramilli
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
| | - Pawel K Dominik
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
| | - Dawid Deneka
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
| | - Piotr Tokarz
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
| | - Sangwoo S Kim
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
| | - Bharat G Reddy
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
| | - Blazej M Skrobek
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA; Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, Gdansk, Poland
| | - Olivier Dalmas
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
| | - Eduardo Perozo
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA; Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL, USA
| | - Anthony A Kossiakoff
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA; Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA.
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2
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Lansky S, Betancourt JM, Zhang J, Jiang Y, Kim ED, Paknejad N, Nimigean CM, Yuan P, Scheuring S. A pentameric TRPV3 channel with a dilated pore. Nature 2023; 621:206-214. [PMID: 37648856 PMCID: PMC10584365 DOI: 10.1038/s41586-023-06470-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 07/21/2023] [Indexed: 09/01/2023]
Abstract
Transient receptor potential (TRP) channels are a large, eukaryotic ion channel superfamily that control diverse physiological functions, and therefore are attractive drug targets1-5. More than 210 structures from more than 20 different TRP channels have been determined, and all are tetramers4. Despite this wealth of structures, many aspects concerning TRPV channels remain poorly understood, including the pore-dilation phenomenon, whereby prolonged activation leads to increased conductance, permeability to large ions and loss of rectification6,7. Here, we used high-speed atomic force microscopy (HS-AFM) to analyse membrane-embedded TRPV3 at the single-molecule level and discovered a pentameric state. HS-AFM dynamic imaging revealed transience and reversibility of the pentamer in dynamic equilibrium with the canonical tetramer through membrane diffusive protomer exchange. The pentamer population increased upon diphenylboronic anhydride (DPBA) addition, an agonist that has been shown to induce TRPV3 pore dilation. On the basis of these findings, we designed a protein production and data analysis pipeline that resulted in a cryogenic-electron microscopy structure of the TRPV3 pentamer, showing an enlarged pore compared to the tetramer. The slow kinetics to enter and exit the pentameric state, the increased pentamer formation upon DPBA addition and the enlarged pore indicate that the pentamer represents the structural correlate of pore dilation. We thus show membrane diffusive protomer exchange as an additional mechanism for structural changes and conformational variability. Overall, we provide structural evidence for a non-canonical pentameric TRP-channel assembly, laying the foundation for new directions in TRP channel research.
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Affiliation(s)
- Shifra Lansky
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, USA
| | - John Michael Betancourt
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, USA
- Neuroscience Graduate Program, Graduate School of Medical Sciences, Weill Cornell Medicine, New York, NY, USA
| | - Jingying Zhang
- Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, MO, USA
- Center for the Investigation of Membrane Excitability Diseases, Washington University School of Medicine, Saint Louis, MO, USA
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Yining Jiang
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, USA
- Biochemistry and Structural Biology, Cell and Developmental Biology, and Molecular Biology Program, Graduate School of Medical Sciences, Weill Cornell Medicine, New York, NY, USA
| | - Elizabeth D Kim
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, USA
| | - Navid Paknejad
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Physiology, Biophysics and Systems Biology Graduate Program, Weill Cornell Medical College, New York, NY, USA
| | - Crina M Nimigean
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, USA
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA
| | - Peng Yuan
- Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, MO, USA
- Center for the Investigation of Membrane Excitability Diseases, Washington University School of Medicine, Saint Louis, MO, USA
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Simon Scheuring
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, USA.
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA.
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3
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He Z, Tu YC, Tsai CW, Mount J, Zhang J, Tsai MF, Yuan P. Structure and function of the human mitochondrial MRS2 channel. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.12.553106. [PMID: 37645897 PMCID: PMC10462007 DOI: 10.1101/2023.08.12.553106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
The human Mitochondrial RNA Splicing 2 protein (MRS2) has been implicated in Mg2+ transport across mitochondrial inner membranes, thus playing an important role in Mg2+ homeostasis critical for mitochondrial integrity and function. However, the molecular mechanisms underlying its fundamental channel properties such as ion selectivity and regulation remain unclear. Here, we present structural and functional investigation of MRS2. Cryo-electron microscopy structures in various ionic conditions reveal a pentameric channel architecture and the molecular basis of ion permeation and potential regulation mechanisms. Electrophysiological analyses demonstrate that MRS2 is a Ca2+-regulated, non-selective channel permeable to Mg2+, Ca2+, Na+ and K+, which contrasts with its prokaryotic ortholog, CorA, operating as a Mg2+-gated Mg2+ channel. Moreover, a conserved arginine ring within the pore of MRS2 functions to restrict cation movements, likely preventing the channel from collapsing the proton motive force that drives mitochondrial ATP synthesis. Together, our results provide a molecular framework for further understanding MRS2 in mitochondrial function and disease.
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Affiliation(s)
- Zhihui He
- Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, MO, USA
- These authors contributed equally to this work
| | - Yung-Chi Tu
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- These authors contributed equally to this work
| | - Chen-Wei Tsai
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Jonathan Mount
- Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, MO, USA
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Jingying Zhang
- Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, MO, USA
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ming-Feng Tsai
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Peng Yuan
- Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, MO, USA
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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4
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Li M, Li Y, Lu Y, Li J, Lu X, Ren Y, Wen T, Wang Y, Chang S, Zhang X, Yang X, Shen Y. Molecular basis of Mg 2+ permeation through the human mitochondrial Mrs2 channel. Nat Commun 2023; 14:4713. [PMID: 37543649 PMCID: PMC10404273 DOI: 10.1038/s41467-023-40516-2] [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: 03/21/2023] [Accepted: 07/25/2023] [Indexed: 08/07/2023] Open
Abstract
Mitochondrial RNA splicing 2 (Mrs2), a eukaryotic CorA ortholog, enables Mg2+ to permeate the inner mitochondrial membrane and plays an important role in mitochondrial metabolic function. However, the mechanism by which Mrs2 permeates Mg2+ remains unclear. Here, we report four cryo-electron microscopy (cryo-EM) reconstructions of Homo sapiens Mrs2 (hMrs2) under various conditions. All of these hMrs2 structures form symmetrical pentamers with very similar pentamer and protomer conformations. A special structural feature of Cl--bound R-ring, which consists of five Arg332 residues, was found in the hMrs2 structure. Molecular dynamics simulations and mitochondrial Mg2+ uptake assays show that the R-ring may function as a charge repulsion barrier, and Cl- may function as a ferry to jointly gate Mg2+ permeation in hMrs2. In addition, the membrane potential is likely to be the driving force for Mg2+ permeation. Our results provide insights into the channel assembly and Mg2+ permeation of hMrs2.
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Affiliation(s)
- Ming Li
- State Key Laboratory of Medicinal Chemical Biology and Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin, 300350, China
| | - Yang Li
- State Key Laboratory of Medicinal Chemical Biology and Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin, 300350, China
| | - Yue Lu
- State Key Laboratory of Medicinal Chemical Biology and Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin, 300350, China
| | - Jianhui Li
- State Key Laboratory of Medicinal Chemical Biology and Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin, 300350, China
| | - Xuhang Lu
- State Key Laboratory of Medicinal Chemical Biology and Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin, 300350, China
| | - Yue Ren
- State Key Laboratory of Medicinal Chemical Biology and Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin, 300350, China
| | - Tianlei Wen
- State Key Laboratory of Medicinal Chemical Biology and Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin, 300350, China
| | - Yaojie Wang
- State Key Laboratory of Medicinal Chemical Biology and Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin, 300350, China
| | - Shenghai Chang
- Department of Biophysics and Department of Pathology of Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, 310058, China
- Center of Cryo Electron Microscopy, Zhejiang University, Hangzhou, 310058, China
| | - Xing Zhang
- Department of Biophysics and Department of Pathology of Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, 310058, China
- Center of Cryo Electron Microscopy, Zhejiang University, Hangzhou, 310058, China
| | - Xue Yang
- State Key Laboratory of Medicinal Chemical Biology and Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin, 300350, China.
| | - Yuequan Shen
- State Key Laboratory of Medicinal Chemical Biology and Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin, 300350, China.
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5
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Zheng LE, Barethiya S, Nordquist E, Chen J. Machine Learning Generation of Dynamic Protein Conformational Ensembles. Molecules 2023; 28:4047. [PMID: 37241789 PMCID: PMC10220786 DOI: 10.3390/molecules28104047] [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: 04/10/2023] [Revised: 05/04/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023] Open
Abstract
Machine learning has achieved remarkable success across a broad range of scientific and engineering disciplines, particularly its use for predicting native protein structures from sequence information alone. However, biomolecules are inherently dynamic, and there is a pressing need for accurate predictions of dynamic structural ensembles across multiple functional levels. These problems range from the relatively well-defined task of predicting conformational dynamics around the native state of a protein, which traditional molecular dynamics (MD) simulations are particularly adept at handling, to generating large-scale conformational transitions connecting distinct functional states of structured proteins or numerous marginally stable states within the dynamic ensembles of intrinsically disordered proteins. Machine learning has been increasingly applied to learn low-dimensional representations of protein conformational spaces, which can then be used to drive additional MD sampling or directly generate novel conformations. These methods promise to greatly reduce the computational cost of generating dynamic protein ensembles, compared to traditional MD simulations. In this review, we examine recent progress in machine learning approaches towards generative modeling of dynamic protein ensembles and emphasize the crucial importance of integrating advances in machine learning, structural data, and physical principles to achieve these ambitious goals.
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Affiliation(s)
- Li-E Zheng
- Department of Gynecology, The First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, China;
| | - Shrishti Barethiya
- Department of Chemistry, University of Massachusetts Amherst, Amherst, MA 01003, USA; (S.B.); (E.N.)
| | - Erik Nordquist
- Department of Chemistry, University of Massachusetts Amherst, Amherst, MA 01003, USA; (S.B.); (E.N.)
| | - Jianhan Chen
- Department of Chemistry, University of Massachusetts Amherst, Amherst, MA 01003, USA; (S.B.); (E.N.)
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6
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Erramilli SK, Dominik PK, Deneka D, Tokarz P, Kim SS, Reddy BG, Skrobek BM, Dalmas O, Perozo E, Kossiakoff AA. Conformation-specific synthetic antibodies discriminate multiple functional states of the ion channel CorA. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.07.539746. [PMID: 37205530 PMCID: PMC10187328 DOI: 10.1101/2023.05.07.539746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
CorA, the primary magnesium ion channel in prokaryotes and archaea, is a prototypical homopentameric ion channel that undergoes ion-dependent conformational transitions. CorA adopts five-fold symmetric non-conductive states in the presence of high concentrations of Mg 2+ , and highly asymmetric flexible states in its complete absence. However, the latter were of insufficient resolution to be thoroughly characterized. In order to gain additional insights into the relationship between asymmetry and channel activation, we exploited phage display selection strategies to generate conformation-specific synthetic antibodies (sABs) against CorA in the absence of Mg 2+ . Two sABs from these selections, C12 and C18, showed different degrees of Mg 2+ -sensitivity. Through structural, biochemical, and biophysical characterization, we found the sABs are both conformation-specific but probe different features of the channel under open-like conditions. C18 is highly specific to the Mg 2+ -depleted state of CorA and through negative-stain electron microscopy (ns-EM), we show sAB binding reflects the asymmetric arrangement of CorA protomers in Mg 2+ -depleted conditions. We used X-ray crystallography to determine a structure at 2.0 Å resolution of sAB C12 bound to the soluble N-terminal regulatory domain of CorA. The structure shows C12 is a competitive inhibitor of regulatory magnesium binding through its interaction with the divalent cation sensing site. We subsequently exploited this relationship to capture and visualize asymmetric CorA states in different [Mg 2+ ] using ns-EM. We additionally utilized these sABs to provide insights into the energy landscape that governs the ion-dependent conformational transitions of CorA.
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7
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Uthayabalan S, Vishnu N, Madesh M, Stathopulos PB. The human MRS2 magnesium-binding domain is a regulatory feedback switch for channel activity. Life Sci Alliance 2023; 6:e202201742. [PMID: 36754568 PMCID: PMC9909464 DOI: 10.26508/lsa.202201742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 01/25/2023] [Accepted: 01/26/2023] [Indexed: 02/10/2023] Open
Abstract
Mitochondrial RNA splicing 2 (MRS2) forms a magnesium (Mg2+) entry protein channel in mitochondria. Whereas MRS2 contains two transmembrane domains constituting a pore on the inner mitochondrial membrane, most of the protein resides within the matrix. Yet, the precise structural and functional role of this obtrusive amino terminal domain (NTD) in human MRS2 is unknown. Here, we show that the MRS2 NTD self-associates into a homodimer, contrasting the pentameric assembly of CorA, an orthologous bacterial channel. Mg2+ and calcium suppress lower and higher order oligomerization of MRS2 NTD, whereas cobalt has no effect on the NTD but disassembles full-length MRS2. Mutating-pinpointed residues-mediating Mg2+ binding to the NTD not only selectively decreases Mg2+-binding affinity ∼sevenfold but also abrogates Mg2+ binding-induced secondary, tertiary, and quaternary structure changes. Disruption of NTD Mg2+ binding strikingly potentiates mitochondrial Mg2+ uptake in WT and Mrs2 knockout cells. Our work exposes a mechanism for human MRS2 autoregulation by negative feedback from the NTD and identifies a novel gain of function mutant with broad applicability to future Mg2+ signaling research.
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Affiliation(s)
- Sukanthathulse Uthayabalan
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| | - Neelanjan Vishnu
- Center for Mitochondrial Medicine, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Muniswamy Madesh
- Center for Mitochondrial Medicine, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Peter B Stathopulos
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
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8
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Raghuraman H, Böckmann A. Editorial: Structural dynamics of membrane proteins, Volume II. Front Mol Biosci 2022; 9:1037083. [PMID: 36310593 PMCID: PMC9608756 DOI: 10.3389/fmolb.2022.1037083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 09/27/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
- H. Raghuraman
- Crystallography and Molecular Biology Division, Saha Institute of Nuclear Physics, Homi Bhabha National Institute, Kolkata, India
- *Correspondence: H. Raghuraman, ; Anja Böckmann,
| | - Anja Böckmann
- Microbiologie Moléculaire et Biochimie Structurale (MMSB), UMR5086 CNRS, Lyon University, Lyon, France
- *Correspondence: H. Raghuraman, ; Anja Böckmann,
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9
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Zhu Y, Wang Y, Zhang Y, Pu M, Miao W, Bai M, Bao R, Geng J. Ion selectivity and gating behavior of the CorA-type channel Bpss1228. Front Chem 2022; 10:998075. [PMID: 36171999 PMCID: PMC9511408 DOI: 10.3389/fchem.2022.998075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 08/25/2022] [Indexed: 11/24/2022] Open
Abstract
Magnesium is an essential element to sustain all forms of life. Total intracellular magnesium content is determined by the balance of magnesium influx and efflux. CorA is a divalent selective channel in the metal ion transport superfamily and is the major Mg2+ uptake pathway in prokaryotes and eukaryotic mitochondria. Previous studies have demonstrated that CorA showed distinct magnesium bound closed conformation and Mg2+-free states. In addition, CorA is regulated by cytoplasmic magnesium ions and its gating mechanism has been investigated by electron paramagnetic resonance technique and molecular dynamic simulations. Here, we report a study of the putative CorA-type channel Bpss1228 from Burkholderia pseudomallei, which has been shown to be significantly associated with pseudomallei infection. We expressed and purified the Bpss1228 in full-length. Subsequently, electrophysiological experiments further investigated the electrical characteristics of Bpss1228 and revealed that it was a strictly cation-selective channel. We also proved that Bpss1228 not only possessed magnesium-mediated regulatory property a remarkable ability to be modulated by magnesium ions. Finally, we observed the three-step gating behavior of Bpss1228 on planar lipid bilayer, and further proposed a synergistic gating mechanism by which CorA family channels control intracellular magnesium homeostasis.
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Affiliation(s)
| | | | | | | | | | | | - Rui Bao
- *Correspondence: Rui Bao, ; Jia Geng,
| | - Jia Geng
- *Correspondence: Rui Bao, ; Jia Geng,
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10
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Jin F, Huang Y, Hattori M. Recent Advances in the Structural Biology of Mg 2+ Channels and Transporters. J Mol Biol 2022; 434:167729. [PMID: 35841930 DOI: 10.1016/j.jmb.2022.167729] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 07/06/2022] [Accepted: 07/07/2022] [Indexed: 10/17/2022]
Abstract
Magnesium ions (Mg2+) are the most abundant divalent cations in living organisms and are essential for various physiological processes, including ATP utilization and the catalytic activity of numerous enzymes. Therefore, the homeostatic mechanisms associated with cellular Mg2+ are crucial for both eukaryotic and prokaryotic organisms and are thus strictly controlled by Mg2+ channels and transporters. Technological advances in structural biology, such as the expression screening of membrane proteins, in meso phase crystallization, and recent cryo-EM techniques, have enabled the structure determination of numerous Mg2+ channels and transporters. In this review article, we provide an overview of the families of Mg2+ channels and transporters (MgtE/SLC41, TRPM6/7, CorA/Mrs2, CorC/CNNM), and discuss the structural biology prospects based on the known structures of MgtE, TRPM7, CorA and CorC.
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Affiliation(s)
- Fei Jin
- State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Bioactive Small Molecules, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Neurobiology, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Yichen Huang
- State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Bioactive Small Molecules, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Neurobiology, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Motoyuki Hattori
- State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Bioactive Small Molecules, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Neurobiology, School of Life Sciences, Fudan University, Shanghai 200438, China.
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11
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Amyot R, Marchesi A, Franz CM, Casuso I, Flechsig H. Simulation atomic force microscopy for atomic reconstruction of biomolecular structures from resolution-limited experimental images. PLoS Comput Biol 2022; 18:e1009970. [PMID: 35294442 PMCID: PMC8959186 DOI: 10.1371/journal.pcbi.1009970] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 03/28/2022] [Accepted: 02/25/2022] [Indexed: 11/18/2022] Open
Abstract
Atomic force microscopy (AFM) can visualize the dynamics of single biomolecules under near-physiological conditions. However, the scanning tip probes only the molecular surface with limited resolution, missing details required to fully deduce functional mechanisms from imaging alone. To overcome such drawbacks, we developed a computational framework to reconstruct 3D atomistic structures from AFM surface scans, employing simulation AFM and automatized fitting to experimental images. We provide applications to AFM images ranging from single molecular machines, protein filaments, to large-scale assemblies of 2D protein lattices, and demonstrate how the obtained full atomistic information advances the molecular understanding beyond the original topographic AFM image. We show that simulation AFM further allows for quantitative molecular feature assignment within measured AFM topographies. Implementation of the developed methods into the versatile interactive interface of the BioAFMviewer software, freely available at www.bioafmviewer.com, presents the opportunity for the broad Bio-AFM community to employ the enormous amount of existing structural and modeling data to facilitate the interpretation of resolution-limited AFM images.
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Affiliation(s)
- Romain Amyot
- Aix Marseille University, CNRS, INSERM, LAI, Turing Centre for Living Systems, Marseille, France
| | - Arin Marchesi
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa, Japan
| | - Clemens M. Franz
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa, Japan
| | - Ignacio Casuso
- Aix Marseille University, CNRS, INSERM, LAI, Turing Centre for Living Systems, Marseille, France
| | - Holger Flechsig
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa, Japan
- * E-mail:
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12
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Johansen NT, Bonaccorsi M, Bengtsen T, Larsen AH, Tidemand FG, Pedersen MC, Huda P, Berndtsson J, Darwish T, Yepuri NR, Martel A, Pomorski TG, Bertarello A, Sansom MS, Rapp M, Crehuet R, Schubeis T, Lindorff-Larsen K, Pintacuda G, Arleth L. Mg 2+-dependent conformational equilibria in CorA and an integrated view on transport regulation. eLife 2022; 11:71887. [PMID: 35129435 PMCID: PMC8865849 DOI: 10.7554/elife.71887] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 02/04/2022] [Indexed: 11/13/2022] Open
Abstract
The CorA family of proteins regulates the homeostasis of divalent metal ions in many bacteria, archaea, and eukaryotic mitochondria, making it an important target in the investigation of the mechanisms of transport and its functional regulation. Although numerous structures of open and closed channels are now available for the CorA family, the mechanism of the transport regulation remains elusive. Here, we investigated the conformational distribution and associated dynamic behaviour of the pentameric Mg2+ channel CorA at room temperature using small-angle neutron scattering (SANS) in combination with molecular dynamics (MD) simulations and solid-state nuclear magnetic resonance spectroscopy (NMR). We find that neither the Mg2+-bound closed structure nor the Mg2+-free open forms are sufficient to explain the average conformation of CorA. Our data support the presence of conformational equilibria between multiple states, and we further find a variation in the behaviour of the backbone dynamics with and without Mg2+. We propose that CorA must be in a dynamic equilibrium between different non-conducting states, both symmetric and asymmetric, regardless of bound Mg2+ but that conducting states become more populated in Mg2+-free conditions. These properties are regulated by backbone dynamics and are key to understanding the functional regulation of CorA.
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Affiliation(s)
| | - Marta Bonaccorsi
- Centre de RMN à Très hauts Champs de Lyon, UMR 5280, CNRS, University of Lyon, Villeurbanne, France
| | - Tone Bengtsen
- Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Andreas Haahr Larsen
- Condensed Matter Physics, Niels Bohr Institute, University of Copenhagen, Copenhagen E, Denmark
| | | | - Martin Cramer Pedersen
- Condensed Matter Physics, Niels Bohr Institute, University of Copenhagen, Copenhagen E, Denmark
| | - Pie Huda
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, Brisbane, Australia
| | - Jens Berndtsson
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Tamim Darwish
- National Deuteration Facility, Australian Nuclear Science and Technology Organization, Lucas Heights, Australia
| | - Nageshewar Rao Yepuri
- National Deuteration Facility, Australian Nuclear Science and Technology Organization, Lucas Heights, Australia
| | | | - Thomas Günther Pomorski
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Andrea Bertarello
- Centre de RMN à Très hauts Champs de Lyon, UMR 5280, CNRS, University of Lyon, Villeurbanne, France
| | - Mark Sp Sansom
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Mikaela Rapp
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Ramon Crehuet
- Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Tobias Schubeis
- Centre de RMN à Très hauts Champs de Lyon, UMR 5280, CNRS, University of Lyon, Villeurbanne, France
| | | | - Guido Pintacuda
- Centre de RMN à Très hauts Champs de Lyon, UMR 5280, CNRS, University of Lyon, Villeurbanne, France
| | - Lise Arleth
- Condensed Matter Physics, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
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13
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Cell Envelope Stress Response in Pseudomonas aeruginosa. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1386:147-184. [DOI: 10.1007/978-3-031-08491-1_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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14
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Heath GR, Lin YC, Matin TR, Scheuring S. Structural dynamics of channels and transporters by high-speed atomic force microscopy. Methods Enzymol 2021; 652:127-159. [PMID: 34059280 DOI: 10.1016/bs.mie.2021.03.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Channels and transporters are vital for transmembrane transport of ions and solutes, and also of larger compounds such as lipids and macromolecules. Therefore, they are crucial in many biological processes such as sensing, signal transduction, and the regulation of the distribution of molecules. Dysfunctions of these membrane proteins are associated to numerous diseases, and their interaction with drugs is critical in medicine. Understanding the behavior of channels and transporters requires structural and dynamic information to decipher the molecular mechanisms underlying their function. High-Speed Atomic Force Microscopy (HS-AFM) now allows the study of single transmembrane channels and transporters in action under physiological conditions, i.e., at ambient temperature and pressure, in physiological buffer and in a membrane, and in a most direct, label-free manner. In this chapter, we discuss the HS-AFM sample preparation, application, and data analysis protocols to study the structural and conformational dynamics of membrane-embedded channels and transporters.
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Affiliation(s)
- George R Heath
- School of Physics and Astronomy, University of Leeds, Leeds, United Kingdom
| | - Yi-Chih Lin
- Weill Cornell Medicine, Department of Anesthesiology, New York, NY, United States
| | - Tina R Matin
- Weill Cornell Medicine, Department of Anesthesiology, New York, NY, United States
| | - Simon Scheuring
- Weill Cornell Medicine, Department of Anesthesiology, New York, NY, United States; Weill Cornell Medicine, Department of Physiology and Biophysics, New York, NY, United States.
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15
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Nemchinova M, Melcr J, Wassenaar TA, Marrink SJ, Guskov A. Asymmetric CorA Gating Mechanism as Observed by Molecular Dynamics Simulations. J Chem Inf Model 2021; 61:2407-2417. [PMID: 33886304 PMCID: PMC8154316 DOI: 10.1021/acs.jcim.1c00261] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
The CorA family of
proteins plays a housekeeping role in the homeostasis
of divalent metal ions in many bacteria and archaea as well as in
mitochondria of eukaryotes, rendering it an important target to study
the mechanisms of divalent transport and regulation across different
life domains. Despite numerous studies, the mechanistic details of
the channel gating and the transport of the metal ions are still not
entirely understood. Here, we use all-atom and coarse-grained molecular
dynamics simulations combined with in vitro experiments
to investigate the influence of divalent cations on the function of
CorA. Simulations reveal pronounced asymmetric movements of monomers
that enable the rotation of the α7 helix and the cytoplasmic
subdomain with the subsequent formation of new interactions and the
opening of the channel. These computational results are functionally
validated using site-directed mutagenesis of the intracellular cytoplasmic
domain residues and biochemical assays. The obtained results infer
a complex network of interactions altering the structure of CorA to
allow gating. Furthermore, we attempt to reconcile the existing gating
hypotheses for CorA to conclude the mechanism of transport of divalent
cations via these proteins.
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Affiliation(s)
- Mariia Nemchinova
- Groningen Institute for Biomolecular Sciences and Biotechnology, University of Groningen, 9747AG Groningen, The Netherlands
| | - Josef Melcr
- Groningen Institute for Biomolecular Sciences and Biotechnology, University of Groningen, 9747AG Groningen, The Netherlands
| | - Tsjerk A Wassenaar
- Groningen Institute for Biomolecular Sciences and Biotechnology, University of Groningen, 9747AG Groningen, The Netherlands
| | - Siewert J Marrink
- Groningen Institute for Biomolecular Sciences and Biotechnology, University of Groningen, 9747AG Groningen, The Netherlands
| | - Albert Guskov
- Groningen Institute for Biomolecular Sciences and Biotechnology, University of Groningen, 9747AG Groningen, The Netherlands
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16
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Okumura M, Noi K, Inaba K. Visualization of structural dynamics of protein disulfide isomerase enzymes in catalysis of oxidative folding and reductive unfolding. Curr Opin Struct Biol 2020; 66:49-57. [PMID: 33176263 DOI: 10.1016/j.sbi.2020.10.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 09/18/2020] [Accepted: 10/08/2020] [Indexed: 02/06/2023]
Abstract
Time-resolved single-molecule observations by high-speed atomic force microscopy (HS-AFM), have greatly advanced our understanding of how proteins operate to fulfill their unique functions. Using this device, we succeeded in visualizing two members of the protein disulfide isomerase family (PDIs) that act to catalyze oxidative folding and reductive unfolding in the endoplasmic reticulum (ER). ERdj5, an ER-resident disulfide reductase that promotes ER-associated degradation, reduces nonnative disulfide bonds of misfolded proteins utilizing the dynamics of its N-terminal and C-terminal clusters. With unfolded substrates, canonical PDI assembles to form a face-to-face dimer with a central hydrophobic cavity and multiple redox-active sites to accelerate oxidative folding inside the cavity. Altogether, PDIs exert highly dynamic mechanisms to ensure the protein quality control in the ER.
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Affiliation(s)
- Masaki Okumura
- Frontier Research Institute for Interdisciplinary Sciences, Aramaki aza Aoba 6-3, Aoba-ku, Sendai 980-8578, Japan
| | - Kentaro Noi
- Institute of Nanoscience Design, Osaka University, Machikaneyamatyou 1-3, Toyonaka 560-8531, Japan
| | - Kenji Inaba
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan.
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