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Woll KA, Van Petegem F. Calcium Release Channels: Structure and Function of IP3 Receptors and Ryanodine Receptors. Physiol Rev 2021; 102:209-268. [PMID: 34280054 DOI: 10.1152/physrev.00033.2020] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Ca2+-release channels are giant membrane proteins that control the release of Ca2+ from the endoplasmic and sarcoplasmic reticulum. The two members, ryanodine receptors (RyRs) and inositol-1,4,5-trisphosphate Receptors (IP3Rs), are evolutionarily related and are both activated by cytosolic Ca2+. They share a common architecture, but RyRs have evolved additional modules in the cytosolic region. Their massive size allows for the regulation by tens of proteins and small molecules, which can affect the opening and closing of the channels. In addition to Ca2+, other major triggers include IP3 for the IP3Rs, and depolarization of the plasma membrane for a particular RyR subtype. Their size has made them popular targets for study via electron microscopic methods, with current structures culminating near 3Å. The available structures have provided many new mechanistic insights int the binding of auxiliary proteins and small molecules, how these can regulate channel opening, and the mechanisms of disease-associated mutations. They also help scrutinize previously proposed binding sites, as some of these are now incompatible with the structures. Many questions remain around the structural effects of post-translational modifications, additional binding partners, and the higher-order complexes these channels can make in situ. This review summarizes our current knowledge about the structures of Ca2+-release channels and how this informs on their function.
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Affiliation(s)
- Kellie A Woll
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
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Dulhunty AF, Beard NA, Casarotto MG. Recent advances in understanding the ryanodine receptor calcium release channels and their role in calcium signalling. F1000Res 2018; 7. [PMID: 30542613 PMCID: PMC6259491 DOI: 10.12688/f1000research.16434.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/16/2018] [Indexed: 12/30/2022] Open
Abstract
The ryanodine receptor calcium release channel is central to cytoplasmic Ca
2+ signalling in skeletal muscle, the heart, and many other tissues, including the central nervous system, lymphocytes, stomach, kidney, adrenal glands, ovaries, testes, thymus, and lungs. The ion channel protein is massive (more than 2.2 MDa) and has a structure that has defied detailed determination until recent developments in cryo-electron microscopy revealed much of its structure at near-atomic resolution. The availability of this high-resolution structure has provided the most significant advances in understanding the function of the ion channel in the past 30 years. We can now visualise the molecular environment of individual amino acid residues that form binding sites for essential modulators of ion channel function and determine its role in Ca
2+ signalling. Importantly, the structure has revealed the structural environment of the many deletions and point mutations that disrupt Ca
2+ signalling in skeletal and cardiac myopathies and neuropathies. The implications are of vital importance to our understanding of the molecular basis of the ion channel’s function and for the design of therapies to counteract the effects of ryanodine receptor-associated disorders.
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Affiliation(s)
- Angela F Dulhunty
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, 131 Garran Road, The Australian National University, Acton, ACT, 2601, Australia
| | - Nicole A Beard
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Bruce, ACT, 2617, Australia
| | - Marco G Casarotto
- Department of Cancer Biology and Therapeutics, John Curtin School of Medical Research, 131 Garran Road, The Australian National University, Acton, ACT, 2601, Australia
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des Georges A, Clarke OB, Zalk R, Yuan Q, Condon KJ, Grassucci RA, Hendrickson WA, Marks AR, Frank J. Structural Basis for Gating and Activation of RyR1. Cell 2016; 167:145-157.e17. [PMID: 27662087 DOI: 10.1016/j.cell.2016.08.075] [Citation(s) in RCA: 256] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 06/08/2016] [Accepted: 08/30/2016] [Indexed: 10/21/2022]
Abstract
The type-1 ryanodine receptor (RyR1) is an intracellular calcium (Ca(2+)) release channel required for skeletal muscle contraction. Here, we present cryo-EM reconstructions of RyR1 in multiple functional states revealing the structural basis of channel gating and ligand-dependent activation. Binding sites for the channel activators Ca(2+), ATP, and caffeine were identified at interdomain interfaces of the C-terminal domain. Either ATP or Ca(2+) alone induces conformational changes in the cytoplasmic assembly ("priming"), without pore dilation. In contrast, in the presence of all three activating ligands, high-resolution reconstructions of open and closed states of RyR1 were obtained from the same sample, enabling analyses of conformational changes associated with gating. Gating involves global conformational changes in the cytosolic assembly accompanied by local changes in the transmembrane domain, which include bending of the S6 transmembrane segment and consequent pore dilation, displacement, and deformation of the S4-S5 linker and conformational changes in the pseudo-voltage-sensor domain.
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Affiliation(s)
- Amédée des Georges
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA; Howard Hughes Medical Institute, Columbia University, New York, NY 10032, USA
| | - Oliver B Clarke
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Ran Zalk
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA
| | - Qi Yuan
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA
| | - Kendall J Condon
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA; Howard Hughes Medical Institute, Columbia University, New York, NY 10032, USA
| | - Robert A Grassucci
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA; Howard Hughes Medical Institute, Columbia University, New York, NY 10032, USA
| | - Wayne A Hendrickson
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA; Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA.
| | - Andrew R Marks
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA; Department of Medicine, Columbia University, New York, NY 10032, USA; Wu Center for Molecular Cardiology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
| | - Joachim Frank
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA; Howard Hughes Medical Institute, Columbia University, New York, NY 10032, USA; Department of Biological Sciences, Columbia University, New York, NY 10032, USA.
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Clarke OB, Hendrickson WA. Structures of the colossal RyR1 calcium release channel. Curr Opin Struct Biol 2016; 39:144-152. [PMID: 27687475 PMCID: PMC5419430 DOI: 10.1016/j.sbi.2016.09.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 09/05/2016] [Indexed: 01/19/2023]
Abstract
Ryanodine receptors (RyRs) are intracellular cation channels that mediate the rapid and voluminous release of Ca2+ from the sarcoplasmic reticulum (SR) as required for excitation-contraction coupling in cardiac and skeletal muscle. Understanding of the architecture and gating of RyRs has advanced dramatically over the past two years, due to the publication of high resolution cryo-electron microscopy (cryoEM) reconstructions and associated atomic models of multiple functional states of the skeletal muscle receptor, RyR1. Here we review recent advances in our understanding of RyR architecture and gating, and highlight remaining gaps in understanding which we anticipate will soon be filled.
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Affiliation(s)
- Oliver B Clarke
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Wayne A Hendrickson
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.
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Euden J, Mason SA, Viero C, Thomas NL, Williams AJ. Investigations of the contribution of a putative glycine hinge to ryanodine receptor channel gating. J Biol Chem 2013; 288:16671-16679. [PMID: 23632022 PMCID: PMC3675601 DOI: 10.1074/jbc.m113.465310] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Ryanodine receptor channels (RyR) are key components of striated muscle excitation-contraction coupling, and alterations in their function underlie both inherited and acquired disease. A full understanding of the disease process will require a detailed knowledge of the mechanisms and structures involved in RyR function. Unfortunately, high-resolution structural data, such as exist for K+-selective channels, are not available for RyR. In the absence of these data, we have used modeling to identify similarities in the structural elements of K+ channel pore-forming regions and postulated equivalent regions of RyR. This has identified a sequence of residues in the cytosolic cavity-lining transmembrane helix of RyR (G4864LIIDA4869 in RyR2) analogous to the glycine hinge motif present in many K+ channels. Gating in these K+ channels can be disrupted by substitution of residues for the hinge glycine. We investigated the involvement of glycine 4864 in RyR2 gating by monitoring properties of recombinant human RyR2 channels in which this glycine is replaced by residues that alter gating in K+ channels. Our data demonstrate that introducing alanine at position 4864 produces no significant change in RyR2 function. In contrast, function is altered when glycine 4864 is replaced by either valine or proline, the former preventing channel opening and the latter modifying both ion translocation and gating. Our studies reveal novel information on the structural basis of RyR gating, identifying both similarities with, and differences from, K+ channels. Glycine 4864 is not absolutely required for channel gating, but some flexibility at this point in the cavity-lining transmembrane helix is necessary for normal RyR function.
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Affiliation(s)
- Joanne Euden
- Institute of Molecular and Experimental Medicine, Cardiff University, Cardiff CF14 4XN, Wales, United Kingdom
| | - Sammy A Mason
- Institute of Molecular and Experimental Medicine, Cardiff University, Cardiff CF14 4XN, Wales, United Kingdom
| | - Cedric Viero
- Institute of Molecular and Experimental Medicine, Cardiff University, Cardiff CF14 4XN, Wales, United Kingdom
| | - N Lowri Thomas
- Institute of Molecular and Experimental Medicine, Cardiff University, Cardiff CF14 4XN, Wales, United Kingdom
| | - Alan J Williams
- Institute of Molecular and Experimental Medicine, Cardiff University, Cardiff CF14 4XN, Wales, United Kingdom.
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Diaz-Sylvester PL, Copello JA. Voltage-dependent modulation of cardiac ryanodine receptors (RyR2) by protamine. PLoS One 2009; 4:e8315. [PMID: 20016815 PMCID: PMC2789381 DOI: 10.1371/journal.pone.0008315] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Accepted: 11/19/2009] [Indexed: 11/18/2022] Open
Abstract
It has been reported that protamine (>10 µg/ml) blocks single skeletal RyR1 channels and inhibits RyR1-mediated Ca2+ release from sarcoplasmic reticulum microsomes. We extended these studies to cardiac RyR2 reconstituted into planar lipid bilayers. We found that protamine (0.02–20 µg/ml) added to the cytosolic surface of fully activated RyR2 affected channel activity in a voltage-dependent manner. At membrane voltage (Vm; SR lumen - cytosol) = 0 mV, protamine induced conductance transitions to several intermediate states (substates) as well as full block of RyR2. At Vm>10 mV, the substate with the highest level of conductance was predominant. Increasing Vm from 0 to +80 mV, decreased the number of transitions and residence of the channel in this substate. The drop in current amplitude (full opening to substate) had the same magnitude at 0 and +80 mV despite the ∼3-fold increase in amplitude of the full opening. This is more similar to rectification of channel conductance induced by other polycations than to the action of selective conductance modifiers (ryanoids, imperatoxin). A distinctive effect of protamine (which might be shared with polylysines and histones but not with non-peptidic polycations) is the activation of RyR2 in the presence of nanomolar cytosolic Ca2+ and millimolar Mg2+ levels. Our results suggest that RyRs would be subject to dual modulation (activation and block) by polycationic domains of neighboring proteins via electrostatic interactions. Understanding these interactions could be important as such anomalies may be associated with the increased RyR2-mediated Ca2+ leak observed in cardiac diseases.
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Affiliation(s)
- Paula L. Diaz-Sylvester
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, Illinois, United States of America
| | - Julio A. Copello
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, Illinois, United States of America
- * E-mail:
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