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Pluteanu F, Glaser D, Massing F, Schulte JS, Kirchhefer U. Loss of protein phosphatase 2A regulatory subunit PPP2R5A is associated with increased incidence of stress-induced proarrhythmia. Front Cardiovasc Med 2024; 11:1419597. [PMID: 38863902 PMCID: PMC11165201 DOI: 10.3389/fcvm.2024.1419597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Accepted: 05/16/2024] [Indexed: 06/13/2024] Open
Abstract
Background Protein phosphatase 2A (PP2A) is a serine/threonine-selective holoenzyme that controls Ca2+ homeostasis and contractility of the heart via dephosphorylation of regulatory proteins. In some genetically modified mouse models with increased arrhythmogenicity, a reduced expression of the regulatory subunit B56α of PP2A was found as a concomitant effect. Whether there is a general correlation between the abundance of B56α and the promotion of cardiac arrhythmogenesis remains unclear. Methods The aim of this study was therefore to investigate the role of PP2A-B56α in the propensity for arrhythmic activity in the heart. The experimental analysis of this question has been addressed by using a mouse model with deletion of the PP2A-B56α gene, PPP2R5A (KO), in comparison to wild-type animals (WT). Evidence for arrhythmogenicity was investigated in whole animal, isolated heart and cardiomyocytes by ECG, recording of monophasic action potential (MAP) induced by programmed electrical stimulation (PES), measurement of Ca2+ transients under increased pacing frequencies and determination of total K+ channel currents (I K). Results ECG measurements showed a prolongation of QT time in KO vs. WT. KO mice exhibited a higher rate of premature ventricular contractions in the ECG. MAP measurements in Langendorff-perfused KO hearts showed increased episodes of ventricular tachyarrhythmia induced by PES. However, the KO hearts showed values for MAP duration that were similar to those in WT hearts. In contrast, KO showed more myocardial cells with spontaneous arrhythmogenic Ca2+ transient events compared to WT. The whole-cell patch-clamp technique applied to ventricular cardiomyocytes revealed comparable peak potassium channel current densities between KO and WT. Conclusion These findings support the assumption that a decrease or even the loss of PP2A-B56α leads to an increased propensity of triggered arrhythmias. This could be based on the increased spontaneous Ca2+ tansients observed.
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Affiliation(s)
- Florentina Pluteanu
- Department of Anatomy, Animal Physiology and Biophysics, University of Bucharest, Bucharest, Romania
| | - Dennis Glaser
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, Universität Münster, Münster, Germany
| | - Fabian Massing
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, Universität Münster, Münster, Germany
| | - Jan S. Schulte
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, Universität Münster, Münster, Germany
| | - Uwe Kirchhefer
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, Universität Münster, Münster, Germany
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Asghari P, Scriven DR, Shahrasebi S, Valdivia HH, Alsina KM, Valdivia CR, Navarro-Garcia JA, Wehrens XH, Moore ED. Phosphorylation of RyR2 simultaneously expands the dyad and rearranges the tetramers. J Gen Physiol 2024; 156:e202213108. [PMID: 38385988 PMCID: PMC10883851 DOI: 10.1085/jgp.202213108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 01/23/2023] [Accepted: 01/31/2024] [Indexed: 02/23/2024] Open
Abstract
We have previously demonstrated that type II ryanodine receptors (RyR2) tetramers can be rapidly rearranged in response to a phosphorylation cocktail. The cocktail modified downstream targets indiscriminately, making it impossible to determine whether phosphorylation of RyR2 was an essential element of the response. Here, we used the β-agonist isoproterenol and mice homozygous for one of the following clinically relevant mutations: S2030A, S2808A, S2814A, or S2814D. We measured the length of the dyad using transmission electron microscopy (TEM) and directly visualized RyR2 distribution using dual-tilt electron tomography. We found that the S2814D mutation, by itself, significantly expanded the dyad and reorganized the tetramers, suggesting a direct link between the phosphorylation state of the tetramer and its microarchitecture. S2808A and S2814A mutant mice, as well as wild types, had significant expansions of their dyads in response to isoproterenol, while S2030A mutants did not. In agreement with functional data from these mutants, S2030 and S2808 were necessary for a complete β-adrenergic response, unlike S2814 mutants. Additionally, all mutants had unique effects on the organization of their tetramer arrays. Lastly, the correlation of structural with functional changes suggests that tetramer-tetramer contacts play an important functional role. We thus conclude that both the size of the dyad and the arrangement of the tetramers are linked to the state of the channel tetramer and can be dynamically altered by a β-adrenergic receptor agonist.
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Affiliation(s)
- Parisa Asghari
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, Canada
| | - David R.L. Scriven
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, Canada
| | - Saba Shahrasebi
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, Canada
| | - Hector H. Valdivia
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | | | - Carmen R. Valdivia
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - J. Alberto Navarro-Garcia
- Department of Integrative Physiology, Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Xander H.T. Wehrens
- Department of Integrative Physiology, Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Edwin D.W. Moore
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, Canada
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3
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Barber KR, Vizcarra VS, Zilch A, Majuta L, Diezel CC, Culver OP, Hughes BW, Taniguchi M, Streicher JM, Vanderah TW, Riegel AC. The Role of Ryanodine Receptor 2 in Drug-Associated Learning. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.03.560743. [PMID: 37873212 PMCID: PMC10592901 DOI: 10.1101/2023.10.03.560743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Type-2 ryanodine receptor (RyR2) ion channels facilitate the release of Ca 2+ from stores and serve an important function in neuroplasticity. The role for RyR2 in hippocampal-dependent learning and memory is well established and chronic hyperphosphorylation of RyR2 (RyR2P) is associated with pathological calcium leakage and cognitive disorders, including Alzheimer's disease. By comparison, little is known about the role of RyR2 in the ventral medial prefrontal cortex (vmPFC) circuitry important for working memory, decision making, and reward seeking. Here, we evaluated the basal expression and localization of RyR2 and RyR2P in the vmPFC. Next, we employed an operant model of sucrose, cocaine, or morphine self-administration (SA) followed by a (reward-free) recall test, to reengage vmPFC neurons and reactivate reward-seeking and re-evaluated the expression and localization of RyR2 and RyR2P in vmPFC. Under basal conditions, RyR2 was expressed in pyramidal cells but not regularly detected in PV/SST interneurons. On the contrary, RyR2P was rarely observed in PFC somata and was restricted to a different subcompartment of the same neuron - the apical dendrites of layer-5 pyramidal cells. Chronic SA of drug (cocaine or morphine) and nondrug (sucrose) rewards produced comparable increases in RyR2 protein expression. However, recalling either drug reward impaired the usual localization of RyR2P in dendrites and markedly increased its expression in somata immunoreactive for Fos, a marker of highly activated neurons. These effects could not be explained by chronic stress or drug withdrawal and instead appeared to require a recall experience associated with prior drug SA. In addition to showing the differential distribution of RyR2/RyR2P and affirming the general role of vmPFC in reward learning, this study provides information on the propensity of addictive drugs to redistribute RyR2P ion channels in a neuronal population engaged in drug-seeking. Hence, focusing on the early impact of addictive drugs on RyR2 function may serve as a promising approach to finding a treatment for substance use disorders.
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4
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Dries E, Gilbert G, Roderick HL, Sipido KR. The ryanodine receptor microdomain in cardiomyocytes. Cell Calcium 2023; 114:102769. [PMID: 37390591 DOI: 10.1016/j.ceca.2023.102769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/11/2023] [Accepted: 06/12/2023] [Indexed: 07/02/2023]
Abstract
The ryanodine receptor type 2 (RyR) is a key player in Ca2+ handling during excitation-contraction coupling. During each heartbeat, RyR channels are responsible for linking the action potential with the contractile machinery of the cardiomyocyte by releasing Ca2+ from the sarcoplasmic reticulum. RyR function is fine-tuned by associated signalling molecules, arrangement in clusters and subcellular localization. These parameters together define RyR function within microdomains and are subject to disease remodelling. This review describes the latest findings on RyR microdomain organization, the alterations with disease which result in increased subcellular heterogeneity and emergence of microdomains with enhanced arrhythmogenic potential, and presents novel technologies that guide future research to study and target RyR channels within specific microdomains.
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Affiliation(s)
- Eef Dries
- Lab of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium.
| | - Guillaume Gilbert
- Lab of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium; Laboratoire ORPHY EA 4324, Université de Brest, Brest, France
| | - H Llewelyn Roderick
- Lab of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Karin R Sipido
- Lab of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
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Walweel K, Beard N, van Helden DF, Laver DR. Dantrolene inhibition of ryanodine channels (RyR2) in artificial lipid bilayers depends on FKBP12.6. J Gen Physiol 2023; 155:e202213277. [PMID: 37279522 PMCID: PMC10244881 DOI: 10.1085/jgp.202213277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 03/18/2023] [Accepted: 05/22/2023] [Indexed: 06/08/2023] Open
Abstract
Dantrolene is a neutral hydantoin that is clinically used as a skeletal muscle relaxant to prevent overactivation of the skeletal muscle calcium release channel (RyR1) in response to volatile anesthetics. Dantrolene has aroused considerable recent interest as a lead compound for stabilizing calcium release due to overactive cardiac calcium release channels (RyR2) in heart failure. Previously, we found that dantrolene produces up to a 45% inhibition RyR2 with an IC50 of 160 nM, and that this inhibition requires the physiological association between RyR2 and CaM. In this study, we tested the hypothesis that dantrolene inhibition of RyR2 in the presence of CaM is modulated by RyR2 phosphorylation at S2808 and S2814. Phosphorylation was altered by incubations with either exogenous phosphatase (PP1) or kinases; PKA to phosphorylate S2808 or endogenous CaMKII to phosphorylate S2814. We found that PKA caused selective dissociation of FKBP12.6 from the RyR2 complex and a loss of dantrolene inhibition. Rapamycin-induced FKBP12.6 dissociation from RyR2 also resulted in the loss of dantrolene inhibition. Subsequent incubations of RyR2 with exogenous FKBP12.6 reinstated dantrolene inhibition. These findings indicate that the inhibitory action of dantrolene on RyR2 depends on RyR2 association with FKBP12.6 in addition to CaM as previously found.
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Affiliation(s)
- Kafa Walweel
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, Australia
| | - Nicole Beard
- Faculty of Science and Technology, University of Canberra, Bruce, Australia
| | - Dirk F. van Helden
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, Australia
| | - Derek R. Laver
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, Australia
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Asghari P, Scriven DRL, Shahrasebi S, Valdivia HH, Wehrens XHT, Moore EDW. PHOSPHORYLATION OF RyR2 SIMULTANEOUSLY EXPANDS THE DYAD AND REARRANGES THE TETRAMERS. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.23.541024. [PMID: 37292875 PMCID: PMC10245935 DOI: 10.1101/2023.05.23.541024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We have previously demonstrated that type II ryanodine receptors (RyR2) tetramers can be rapidly rearranged in response to a phosphorylation cocktail. The cocktail modified downstream targets indiscriminately making it impossible to determine whether phosphorylation of RyR2 was an essential element of the response. We therefore used the β-agonist isoproterenol and mice with one of the homozygous mutations, S2030A +/+ , S2808A +/+ , S2814A +/+ , or S2814D +/+ , to address this question and to elucidate the role of these clinically relevant mutations. We measured the length of the dyad using transmission electron microscopy (TEM) and directly visualized RyR2 distribution using dual-tilt electron tomography. We found that: 1) The S2814D mutation, by itself, significantly expanded the dyad and reorganized the tetramers suggesting a direct link between the phosphorylation state of the tetramer and the microarchitecture. 2) All of the wild-type, as well as the S2808A and S2814A mice, had significant expansions of their dyads in response to ISO, while S2030A did not. 3) In agreement with functional data from the same mutants, S2030 and S2808 were necessary for a complete β-adrenergic response, whereas S2814 was not. 4) All the mutated residues had unique effects on the organization of their tetramer arrays. 5) The correlation of structure with function suggests that tetramer-tetramer contacts play an important functional role. We conclude that both the size of the dyad and the arrangement of the tetramers are linked to the state of the channel tetramer and can be dynamically altered by a β-adrenergic receptor agonist. Summary Analysis of RyR2 mutants suggests a direct link between the phosphorylation state of the channel tetramer and the microarchitecture of the dyad. All phosphorylation site mutations produced significant and unique effects on the structure of the dyad and its response to isoproterenol.
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Wei J, Guo W, Wang R, Paul Estillore J, Belke D, Chen YX, Vallmitjana A, Benitez R, Hove-Madsen L, Chen SRW. RyR2 Serine-2030 PKA Site Governs Ca 2+ Release Termination and Ca 2+ Alternans. Circ Res 2023; 132:e59-e77. [PMID: 36583384 DOI: 10.1161/circresaha.122.321177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND PKA (protein kinase A)-mediated phosphorylation of cardiac RyR2 (ryanodine receptor 2) has been extensively studied for decades, but the physiological significance of PKA phosphorylation of RyR2 remains poorly understood. Recent determination of high-resolution 3-dimensional structure of RyR2 in complex with CaM (calmodulin) reveals that the major PKA phosphorylation site in RyR2, serine-2030 (S2030), is located within a structural pathway of CaM-dependent inactivation of RyR2. This novel structural insight points to a possible role of PKA phosphorylation of RyR2 in CaM-dependent inactivation of RyR2, which underlies the termination of Ca2+ release and induction of cardiac Ca2+ alternans. METHODS We performed single-cell endoplasmic reticulum Ca2+ imaging to assess the impact of S2030 mutations on Ca2+ release termination in human embryonic kidney 293 cells. Here we determined the role of the PKA site RyR2-S2030 in a physiological setting, we generated a novel mouse model harboring the S2030L mutation and carried out confocal Ca2+ imaging. RESULTS We found that mutations, S2030D, S2030G, S2030L, S2030V, and S2030W reduced the endoplasmic reticulum luminal Ca2+ level at which Ca2+ release terminates (the termination threshold), whereas S2030P and S2030R increased the termination threshold. S2030A and S2030T had no significant impact on release termination. Furthermore, CaM-wild-type increased, whereas Ca2+ binding deficient CaM mutant (CaM-M [a loss-of-function CaM mutation with all 4 EF-hand motifs mutated]), PKA, and Ca2+/CaMKII (CaM-dependent protein kinase II) reduced the termination threshold. The S2030L mutation abolished the actions of CaM-wild-type, CaM-M, and PKA, but not CaMKII, in Ca2+ release termination. Moreover, we showed that isoproterenol and CaM-M suppressed pacing-induced Ca2+ alternans and accelerated Ca2+ transient recovery in intact working hearts, whereas CaM-wild-type exerted an opposite effect. The impact of isoproterenol was partially and fully reversed by the PKA inhibitor N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinoline-sulfonamide and the CaMKII inhibitor N-[2-[N-(4-chlorocinnamyl)-N-methylaminomethyl]phenyl]-N-(2-hydroxyethyl)-4-methoxybenzenesulfonamide individually and together, respectively. S2030L abolished the impact of CaM-wild-type, CaM-M, and N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinoline-sulfonamide-sensitive component, but not the N-[2-[N-(4-chlorocinnamyl)-N-methylaminomethyl]phenyl]-N-(2-hydroxyethyl)-4-methoxybenzenesulfonamide-sensitive component, of isoproterenol.
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Affiliation(s)
- Jinhong Wei
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta T2N 4N1, Canada (J.W., W.G., R.W., J.P.E., D.B., Y.-X.C., S.R.W.C.).,School of Medicine, Northwest University, Xi 'an, China (J.W.)
| | - Wenting Guo
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta T2N 4N1, Canada (J.W., W.G., R.W., J.P.E., D.B., Y.-X.C., S.R.W.C.)
| | - Ruiwu Wang
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta T2N 4N1, Canada (J.W., W.G., R.W., J.P.E., D.B., Y.-X.C., S.R.W.C.)
| | - John Paul Estillore
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta T2N 4N1, Canada (J.W., W.G., R.W., J.P.E., D.B., Y.-X.C., S.R.W.C.)
| | - Darrell Belke
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta T2N 4N1, Canada (J.W., W.G., R.W., J.P.E., D.B., Y.-X.C., S.R.W.C.)
| | - Yong-Xiang Chen
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta T2N 4N1, Canada (J.W., W.G., R.W., J.P.E., D.B., Y.-X.C., S.R.W.C.)
| | | | - Raul Benitez
- Department of Automatic Control, Universitat Politècnica de Catalunya, 08034 Barcelona, Spain (A.V., R.B.)
| | - Leif Hove-Madsen
- Biomedical Research Institute Barcelona IIBB-CSIC, IIB Sant Pau and CIBERCV, Hospital de Sant Pau, 08025, Barcelona, Spain (L.H.-M.)
| | - S R Wayne Chen
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta T2N 4N1, Canada (J.W., W.G., R.W., J.P.E., D.B., Y.-X.C., S.R.W.C.)
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Chai-Hu-San-Shen Capsule Ameliorates Ventricular Arrhythmia Through Inhibition of the CaMKII/FKBP12.6/RyR2/Ca 2+ Signaling Pathway in Rats with Myocardial Ischemia. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2022; 2022:2670473. [PMID: 36225189 PMCID: PMC9550443 DOI: 10.1155/2022/2670473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 08/18/2022] [Indexed: 11/18/2022]
Abstract
Ventricular arrhythmia is one of the main causes of sudden cardiac death, especially after myocardial ischemia. Previous studies have shown that Chai-Hu-San-Shen capsule (CHSSC) can reduce the incidence of ventricular arrhythmias following myocardial ischemia, however, the mechanisms of it are unclear. In present study, we explored the mechanism of CHSSC ameliorates ventricular arrhythmia following myocardial ischemia via inhibiting the CaMKII/FKBP12.6/RyR2/Ca2+ signaling pathway. In vivo, a myocardial ischemia rat model was established and treated with CHSSC to evaluate the therapeutic effect of CHSSC. In vitro, we established an ischemia model in H9C2 cells and treated with CHSSC, KN-93, or H-89. Then, intracellular Ca2+ content, the expression of RyR2, and the interaction between FKBP12.6 and RyR2 were detected. The results showed that CHSSC could delay the occurrence of ventricular arrhythmias and shorten the duration of ventricular arrhythmias. After myocardial ischemia, the intracellular Ca2+ content was increased, and CHSSC treatment mitigated this increase, down-regulated the levels of p-CaMKII, CaMKII, p-RyR2, and RyR2, and up-regulated the levels of p-RyR2 (Ser2808) and p-RyR2 (Ser2814). Co-immunoprecipitation showed an interaction between FKBP12.6 and RyR2, and CHSSC up-regulated the content of the FKBP12.6-RyR2 complex in ischemic cells. In conclusion, our study showed that CaMKII activation led to hyperphosphorylation of RyR2 (Ser2814) and RyR2 (Ser2808) during cardiomyocyte ischemia, which resulted in dissociation of the FKBP12.6-RyR2 complex, and increased intracellular Ca2+ content, which may contribute to the development of ventricular arrhythmias. CHSSC may reduce the incidence of ventricular arrhythmias following myocardial ischemia through inhibition of the CaMKII/RyR2/FKBP12.6/Ca2+ signaling pathway.
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9
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Shen X, van den Brink J, Bergan-Dahl A, Kolstad TR, Norden ES, Hou Y, Laasmaa M, Aguilar-Sanchez Y, Quick AP, Espe EKS, Sjaastad I, Wehrens XHT, Edwards AG, Soeller C, Louch WE. Prolonged β-adrenergic stimulation disperses ryanodine receptor clusters in cardiomyocytes. eLife 2022; 11:77725. [PMID: 35913125 PMCID: PMC9410709 DOI: 10.7554/elife.77725] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 07/31/2022] [Indexed: 11/17/2022] Open
Abstract
Ryanodine receptors (RyRs) exhibit dynamic arrangements in cardiomyocytes, and we previously showed that ‘dispersion’ of RyR clusters disrupts Ca2+ homeostasis during heart failure (HF) (Kolstad et al., eLife, 2018). Here, we investigated whether prolonged β-adrenergic stimulation, a hallmark of HF, promotes RyR cluster dispersion and examined the underlying mechanisms. We observed that treatment of healthy rat cardiomyocytes with isoproterenol for 1 hr triggered progressive fragmentation of RyR clusters. Pharmacological inhibition of Ca2+/calmodulin-dependent protein kinase II (CaMKII) reversed these effects, while cluster dispersion was reproduced by specific activation of CaMKII, and in mice with constitutively active Ser2814-RyR. A similar role of protein kinase A (PKA) in promoting RyR cluster fragmentation was established by employing PKA activation or inhibition. Progressive cluster dispersion was linked to declining Ca2+ spark fidelity and magnitude, and slowed release kinetics from Ca2+ propagation between more numerous RyR clusters. In healthy cells, this served to dampen the stimulatory actions of β-adrenergic stimulation over the longer term and protect against pro-arrhythmic Ca2+ waves. However, during HF, RyR dispersion was linked to impaired Ca2+ release. Thus, RyR localization and function are intimately linked via channel phosphorylation by both CaMKII and PKA, which, while finely tuned in healthy cardiomyocytes, underlies impaired cardiac function during pathology.
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Affiliation(s)
- Xin Shen
- Institute for Experimental Medical Research, Oslo University Hospital, Oslo, Norway
| | | | - Anna Bergan-Dahl
- Institute for Experimental Medical Research, Oslo University Hospital, Oslo, Norway
| | - Terje R Kolstad
- Insitute for Experimental Medical Research, Oslo University Hospital, Oslo, Norway
| | | | - Yufeng Hou
- KG Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Martin Laasmaa
- Institute for Experimental Medical Research, Oslo University Hospital, Oslo, Norway
| | - Yuriana Aguilar-Sanchez
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, United States
| | - Ann Pepper Quick
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, United States
| | | | - Ivar Sjaastad
- Institute for Experimental Medical Research, Oslo University Hospital, Oslo, Norway
| | - Xander H T Wehrens
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, United States
| | | | | | - William Edward Louch
- Institute for Experimental Medical Research, Oslo University Hospital, Oslo, Norway
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10
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Miotto MC, Weninger G, Dridi H, Yuan Q, Liu Y, Wronska A, Melville Z, Sittenfeld L, Reiken S, Marks AR. Structural analyses of human ryanodine receptor type 2 channels reveal the mechanisms for sudden cardiac death and treatment. SCIENCE ADVANCES 2022; 8:eabo1272. [PMID: 35857850 PMCID: PMC9299551 DOI: 10.1126/sciadv.abo1272] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 06/03/2022] [Indexed: 05/29/2023]
Abstract
Ryanodine receptor type 2 (RyR2) mutations have been linked to an inherited form of exercise-induced sudden cardiac death called catecholaminergic polymorphic ventricular tachycardia (CPVT). CPVT results from stress-induced sarcoplasmic reticular Ca2+ leak via the mutant RyR2 channels during diastole. We present atomic models of human wild-type (WT) RyR2 and the CPVT mutant RyR2-R2474S determined by cryo-electron microscopy with overall resolutions in the range of 2.6 to 3.6 Å, and reaching local resolutions of 2.25 Å, unprecedented for RyR2 channels. Under nonactivating conditions, the RyR2-R2474S channel is in a "primed" state between the closed and open states of WT RyR2, rendering it more sensitive to activation that results in stress-induced Ca2+ leak. The Rycal drug ARM210 binds to RyR2-R2474S, reverting the primed state toward the closed state. Together, these studies provide a mechanism for CPVT and for the therapeutic actions of ARM210.
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Affiliation(s)
- Marco C. Miotto
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Clyde and Helen Wu Center for Molecular Cardiology, Columbia University, New York, NY, USA
| | - Gunnar Weninger
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Clyde and Helen Wu Center for Molecular Cardiology, Columbia University, New York, NY, USA
| | - Haikel Dridi
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Clyde and Helen Wu Center for Molecular Cardiology, Columbia University, New York, NY, USA
| | - Qi Yuan
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Clyde and Helen Wu Center for Molecular Cardiology, Columbia University, New York, NY, USA
| | - Yang Liu
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Clyde and Helen Wu Center for Molecular Cardiology, Columbia University, New York, NY, USA
| | - Anetta Wronska
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Clyde and Helen Wu Center for Molecular Cardiology, Columbia University, New York, NY, USA
| | - Zephan Melville
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Clyde and Helen Wu Center for Molecular Cardiology, Columbia University, New York, NY, USA
| | - Leah Sittenfeld
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Clyde and Helen Wu Center for Molecular Cardiology, Columbia University, New York, NY, USA
| | - Steven Reiken
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Clyde and Helen Wu Center for Molecular Cardiology, Columbia University, New York, NY, USA
| | - Andrew R. Marks
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Clyde and Helen Wu Center for Molecular Cardiology, Columbia University, New York, NY, USA
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11
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Zheng J, Dooge HC, Pérez-Hernández M, Zhao YT, Chen X, Hernandez JJ, Valdivia CR, Palomeque J, Rothenberg E, Delmar M, Valdivia HH, Alvarado FJ. Preserved cardiac performance and adrenergic response in a rabbit model with decreased ryanodine receptor 2 expression. J Mol Cell Cardiol 2022; 167:118-128. [PMID: 35413295 PMCID: PMC9610860 DOI: 10.1016/j.yjmcc.2022.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 03/11/2022] [Accepted: 04/06/2022] [Indexed: 11/19/2022]
Abstract
Ryanodine receptor 2 (RyR2) is an ion channel in the heart responsible for releasing into the cytosol most of the Ca2+ required for contraction. Proper regulation of RyR2 is critical, as highlighted by the association between channel dysfunction and cardiac arrhythmia. Lower RyR2 expression is also observed in some forms of heart disease; however, there is limited information on the impact of this change on excitation-contraction (e-c) coupling, Ca2+-dependent arrhythmias, and cardiac performance. We used a constitutive knock-out of RyR2 in rabbits (RyR2-KO) to assess the extent to which a stable decrease in RyR2 expression modulates Ca2+ handling in the heart. We found that homozygous knock-out of RyR2 in rabbits is embryonic lethal. Remarkably, heterozygotes (KO+/-) show ~50% loss of RyR2 protein without developing an overt phenotype at the intact animal and whole heart levels. Instead, we found that KO+/- myocytes show (1) remodeling of RyR2 clusters, favoring smaller groups in which channels are more densely arranged; (2) lower Ca2+ spark frequency and amplitude; (3) slower rate of Ca2+ release and mild but significant desynchronization of the Ca2+ transient; and (4) a significant decrease in the basal phosphorylation of S2031, likely due to increased association between RyR2 and PP2A. Our data show that RyR2 deficiency, although remarkable at the molecular and subcellular level, has only a modest impact on global Ca2+ release and is fully compensated at the whole-heart level. This highlights the redundancy of RyR2 protein expression and the plasticity of the e-c coupling apparatus.
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Affiliation(s)
- Jingjing Zheng
- Department of Medicine and Cardiovascular Research Center, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA; Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Holly C Dooge
- Department of Medicine and Cardiovascular Research Center, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Marta Pérez-Hernández
- Leon H Charney Division of Cardiology, New York University Grossman School of Medicine,. New York, NY, United States of America
| | - Yan-Ting Zhao
- Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI, United States of America
| | - Xi Chen
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States of America
| | - Jonathan J Hernandez
- Department of Pediatrics, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, United States of America
| | - Carmen R Valdivia
- Department of Medicine and Cardiovascular Research Center, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Julieta Palomeque
- Centro de Investigaciones Cardiovasculares, CCT-La Plata-CONICET, Facultad de Ciencias Médicas, UNLP, La Plata, Argentina
| | - Eli Rothenberg
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY, United States of America
| | - Mario Delmar
- Leon H Charney Division of Cardiology, New York University Grossman School of Medicine,. New York, NY, United States of America
| | - Héctor H Valdivia
- Department of Medicine and Cardiovascular Research Center, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Francisco J Alvarado
- Department of Medicine and Cardiovascular Research Center, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA.
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12
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Lopez R, Janicek R, Fernandez-Tenorio M, Courtehoux M, Matas L, Gerbaud P, Gomez AM, Egger M, Niggli E. Uptake-leak balance of SR Ca2+ determines arrhythmogenic potential of RyR2R420Q+/− cardiomyocytes. J Mol Cell Cardiol 2022; 170:1-14. [DOI: 10.1016/j.yjmcc.2022.05.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 04/01/2022] [Accepted: 05/22/2022] [Indexed: 11/25/2022]
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13
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Therapeutic Approaches of Ryanodine Receptor-Associated Heart Diseases. Int J Mol Sci 2022; 23:ijms23084435. [PMID: 35457253 PMCID: PMC9031589 DOI: 10.3390/ijms23084435] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 04/11/2022] [Accepted: 04/14/2022] [Indexed: 01/08/2023] Open
Abstract
Cardiac diseases are the leading causes of death, with a growing number of cases worldwide, posing a challenge for both healthcare and research. Therefore, the most relevant aim of cardiac research is to unravel the molecular pathomechanisms and identify new therapeutic targets. Cardiac ryanodine receptor (RyR2), the Ca2+ release channel of the sarcoplasmic reticulum, is believed to be a good therapeutic target in a group of certain heart diseases, collectively called cardiac ryanopathies. Ryanopathies are associated with the impaired function of the RyR, leading to heart diseases such as congestive heart failure (CHF), catecholaminergic polymorphic ventricular tachycardia (CPVT), arrhythmogenic right ventricular dysplasia type 2 (ARVD2), and calcium release deficiency syndrome (CRDS). The aim of the current review is to provide a short insight into the pathological mechanisms of ryanopathies and discuss the pharmacological approaches targeting RyR2.
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14
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Regulation of cardiac ryanodine receptor function by the cyclic-GMP dependent protein kinase G. Curr Res Physiol 2022; 5:171-178. [PMID: 35356048 PMCID: PMC8958330 DOI: 10.1016/j.crphys.2022.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 02/20/2022] [Accepted: 03/21/2022] [Indexed: 11/21/2022] Open
Abstract
Background The cGMP-dependent protein kinase G (PKG) phosphorylates the cardiac ryanodine receptor (RyR2) in vitro. We aimed to determine whether modulation of endogenous PKG alters RyR2-mediated spontaneous Ca2+ release and whether this effect is linked to a change in RyR2 phosphorylation. Methods & Results: Human embryonic kidney (HEK293) cells with inducible RyR2 expression were treated with the cGMP analogue 8-Br-cGMP (100 μM) to activate endogenous PKG. In cells transfected with luminal Ca2+ sensor, D1ER, PKG activation significantly reduced the threshold for RyR2-mediated spontaneous Ca2+ release (93.9 ± 0.4% of store size with vehicle vs. 91.7 ± 0.8% with 8-Br-cGMP, P = 0.04). Mutation of the proposed PKG phosphorylation sites, S2808 and S2030, either individually or as a combination, prevented the decrease in Ca2+ release threshold induced by endogenous PKG activation. Interestingly, despite a functional dependence on expression of RyR2 phosphorylation sites, 8-Br-cGMP activation of PKG did not promote a detectable change in S2808 phosphorylation (P = 0.9). Paradoxically, pharmacological inhibition of PKG with KT 5823 (1 μM) also reduced the threshold for spontaneous Ca2+ release through RyR2 without affecting S2808 phosphorylation. Silencing RNA knockdown of endogenous PKG expression also had no quantifiable effect on RyR2 S2808 phosphorylation (P = 0.9). However, unlike PKG inhibition with KT 5823, PKG knockdown did not alter spontaneous Ca2+ release propensity or luminal Ca2+ handling. Conclusion In an intact cell model, activation of endogenous PKG reduces the threshold for RyR2-mediated spontaneous Ca2+ release in a manner dependent on the RyR2 phosphorylation sites S2808 and S2030. This study clarifies the regulation of RyR2 Ca2+ release by endogenous PKG and functionally implicates the role of RyR2 phosphorylation. PKG regulation of RyR2 has been under-researched relative to other kinases. Endogenous PKG activation reduced the threshold for spontaneous RyR2 Ca2+ release. Regulation of RyR2 by PKG required expression of serine residues 2808 and 2030. Knockdown of PKG found minimal basal regulation of RyR2 by PKG.
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15
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Ca 2+ mishandling and mitochondrial dysfunction: a converging road to prediabetic and diabetic cardiomyopathy. Pflugers Arch 2022; 474:33-61. [PMID: 34978597 PMCID: PMC8721633 DOI: 10.1007/s00424-021-02650-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 11/17/2021] [Accepted: 12/03/2021] [Indexed: 12/16/2022]
Abstract
Diabetic cardiomyopathy is defined as the myocardial dysfunction that suffers patients with diabetes mellitus (DM) in the absence of hypertension and structural heart diseases such as valvular or coronary artery dysfunctions. Since the impact of DM on cardiac function is rather silent and slow, early stages of diabetic cardiomyopathy, known as prediabetes, are poorly recognized, and, on many occasions, cardiac illness is diagnosed only after a severe degree of dysfunction was reached. Therefore, exploration and recognition of the initial pathophysiological mechanisms that lead to cardiac dysfunction in diabetic cardiomyopathy are of vital importance for an on-time diagnosis and treatment of the malady. Among the complex and intricate mechanisms involved in diabetic cardiomyopathy, Ca2+ mishandling and mitochondrial dysfunction have been described as pivotal early processes. In the present review, we will focus on these two processes and the molecular pathway that relates these two alterations to the earlier stages and the development of diabetic cardiomyopathy.
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16
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Quantitative Analysis of the Cardiac Phosphoproteome in Response to Acute β-Adrenergic Receptor Stimulation In Vivo. Int J Mol Sci 2021; 22:ijms222212584. [PMID: 34830474 PMCID: PMC8618155 DOI: 10.3390/ijms222212584] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 11/12/2021] [Accepted: 11/15/2021] [Indexed: 11/17/2022] Open
Abstract
β-adrenergic receptor (β-AR) stimulation represents a major mechanism of modulating cardiac output. In spite of its fundamental importance, its molecular basis on the level of cell signalling has not been characterised in detail yet. We employed mass spectrometry-based proteome and phosphoproteome analysis using SuperSILAC (spike-in stable isotope labelling by amino acids in cell culture) standardization to generate a comprehensive map of acute phosphoproteome changes in mice upon administration of isoprenaline (ISO), a synthetic β-AR agonist that targets both β1-AR and β2-AR subtypes. Our data describe 8597 quantitated phosphopeptides corresponding to 10,164 known and novel phospho-events from 2975 proteins. In total, 197 of these phospho-events showed significantly altered phosphorylation, indicating an intricate signalling network activated in response to β-AR stimulation. In addition, we unexpectedly detected significant cardiac expression and ISO-induced fragmentation of junctophilin-1, a junctophilin isoform hitherto only thought to be expressed in skeletal muscle. Data are available via ProteomeXchange with identifier PXD025569.
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Woulfe KC, Jeffrey DA, Pires Da Silva J, Wilson CE, Mahaffey JH, Lau E, Slavov D, Hailu F, Karimpour-Fard A, Dockstader K, Bristow MR, Stauffer BL, Miyamoto SD, Sucharov CC. Serum response factor deletion 5 regulates phospholamban phosphorylation and calcium uptake. J Mol Cell Cardiol 2021; 159:28-37. [PMID: 34139234 PMCID: PMC8546760 DOI: 10.1016/j.yjmcc.2021.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 05/25/2021] [Accepted: 06/13/2021] [Indexed: 11/25/2022]
Abstract
AIMS Pediatric dilated cardiomyopathy (pDCM) is characterized by unique age-dependent molecular mechanisms that include myocellular responses to therapy. We previously showed that pDCM, but not adult DCM patients respond to phosphodiesterase 3 inhibitors (PDE3i) by increasing levels of the second messenger cAMP and consequent phosphorylation of phospholamban (PLN). However, the molecular mechanisms involved in the differential pediatric and adult response to PDE3i are not clear. METHODS AND RESULTS Quantification of serum response factor (SRF) isoforms from the left ventricle of explanted hearts showed that PDE3i treatment affects expression of SRF isoforms in pDCM hearts. An SRF isoform lacking exon 5 (SRFdel5) was highly expressed in the hearts of pediatric, but not adult DCM patients treated with PDE3i. To determine the functional consequence of expression of SRFdel5, we overexpressed full length SRF or SRFdel5 in cultured cardiomyocytes with and without adrenergic stimulation. Compared to a control adenovirus, expression of SRFdel5 increased phosphorylation of PLN, negatively affected expression of the phosphatase that promotes dephosphorylation of PLN (PP2Cε), and promoted faster calcium reuptake, whereas expression of full length SRF attenuated calcium reuptake through blunted phosphorylation of PLN. CONCLUSIONS Taken together, these data indicate that expression of SRFdel5 in pDCM hearts in response to PDE3i contributes to improved function through regulating PLN phosphorylation and thereby calcium reuptake.
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Affiliation(s)
- Kathleen C Woulfe
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Danielle A Jeffrey
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Julie Pires Da Silva
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Cortney E Wilson
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Jennifer H Mahaffey
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Edward Lau
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Dobromir Slavov
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Frehiwet Hailu
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Anis Karimpour-Fard
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Karen Dockstader
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Michael R Bristow
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Brian L Stauffer
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States; Denver Health Medical Center, Denver, CO, United States
| | - Shelley D Miyamoto
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Children's Hospital of Colorado, Aurora, CO, United States
| | - Carmen C Sucharov
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States.
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18
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Complex functionality of protein phosphatase 1 isoforms in the heart. Cell Signal 2021; 85:110059. [PMID: 34062239 DOI: 10.1016/j.cellsig.2021.110059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 05/21/2021] [Accepted: 05/28/2021] [Indexed: 02/04/2023]
Abstract
Protein phosphatase 1(PP1) is a key regulator of cardiac function through dephosphorylating serine/threonine residues within target proteins to oppose the function of protein kinases. Studies from failing hearts of animal models and human patients have demonstrated significant increase of PP1 activity in myocardium, while elevated PP1 activity in transgenic mice leads to cardiac dysfunction, suggesting that PP1 might be a therapeutic target to ameliorate cardiac dysfunction in failing hearts. In fact, cardiac overexpression of inhibitor 1, the endogenous inhibitor of PP1, increases cardiac contractility and suppresses heart failure progression. However, this notion of PP1 inhibition for heart failure treatment has been challenged by recent studies on the isoform-specific roles of PP1 in the heart. PP1 is a holoenzyme composed of catalytic subunits (PP1α, PP1β, or PP1γ) and regulatory proteins that target them to distinct subcellular locations for functional specificity. This review will summarize how PP1 regulates phosphorylation of some of the key cardiac proteins involved in Ca2+ handling and cardiac contraction, and the potential role of PP1 isoforms in controlling cardiac physiology and pathophysiology.
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19
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Gong D, Yan N, Ledford HA. Structural Basis for the Modulation of Ryanodine Receptors. Trends Biochem Sci 2020; 46:489-501. [PMID: 33353849 DOI: 10.1016/j.tibs.2020.11.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 11/16/2020] [Accepted: 11/20/2020] [Indexed: 12/11/2022]
Abstract
Historically, ryanodine receptors (RyRs) have presented unique challenges for high-resolution structural determination despite long-standing interest in their role in excitation-contraction coupling. Owing to their large size (nearly 2.2 MDa), high-resolution structures remained elusive until the advent of cryogenic electron microscopy (cryo-EM) techniques. In recent years, structures for both RyR1 and RyR2 have been solved at near-atomic resolution. Furthermore, recent reports have delved into their more complex structural associations with key modulators - proteins such as the dihydropyridine receptor (DHPR), FKBP12/12.6, and calmodulin (CaM), as well as ions and small molecules including Ca2+, ATP, caffeine, and PCB95. This review addresses the modulation of RyR1 and RyR2, in addition to the impact of such discoveries on intracellular Ca2+ dynamics and biophysical properties.
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Affiliation(s)
- Deshun Gong
- Zhejiang Provincial Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province/Key Laboratory of Growth Regulation and Transformation Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou 310024, Zhejiang, China; Institute of Biology, Westlake Institute for Advanced Study, Hangzhou 310024, Zhejiang Province, China.
| | - Nieng Yan
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
| | - Hannah A Ledford
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
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20
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Multisite phosphorylation of the cardiac ryanodine receptor: a random or coordinated event? Pflugers Arch 2020; 472:1793-1807. [PMID: 33078311 DOI: 10.1007/s00424-020-02473-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 09/03/2020] [Accepted: 10/02/2020] [Indexed: 10/23/2022]
Abstract
Many proteins are phosphorylated at more than one phosphorylation site to achieve precise tuning of protein function and/or integrate a multitude of signals into the activity of one protein. Increasing the number of phosphorylation sites significantly broadens the complexity of molecular mechanisms involved in processing multiple phosphorylation sites by one or more distinct kinases. The cardiac ryanodine receptor (RYR2) is a well-established multiple phospho-target of kinases activated in response to β-adrenergic stimulation because this Ca2+ channel is a critical component of Ca2+ handling machinery which is responsible for β-adrenergic enhancement of cardiac contractility. Our review presents a selective overview of the extensive, often conflicting, literature which focuses on identifying reliable lines of evidence to establish if multiple RYR2 phosphorylation is achieved randomly or in a specific sequence, and whether phosphorylation at individual sites is functionally specific and additive or similar and can therefore be substituted.
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21
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Navarro‐García JA, Rueda A, Romero‐García T, Aceves‐Ripoll J, Rodríguez‐Sánchez E, González‐Lafuente L, Zaragoza C, Fernández‐Velasco M, Kuro‐o M, Ruilope LM, Ruiz‐Hurtado G. Enhanced Klotho availability protects against cardiac dysfunction induced by uraemic cardiomyopathy by regulating Ca 2+ handling. Br J Pharmacol 2020; 177:4701-4719. [PMID: 32830863 PMCID: PMC7520447 DOI: 10.1111/bph.15235] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 07/23/2020] [Accepted: 08/05/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND AND PURPOSE Klotho is a membrane-bound or soluble protein, originally identified as an age-suppressing factor and regulator of mineral metabolism. Klotho deficiency is associated with the development of renal disease, but its role in cardiac function in the context of uraemic cardiomyopathy is unknown. EXPERIMENTAL APPROACH We explored the effects of Klotho on cardiac Ca2+ cycling. We analysed Ca2+ handling in adult cardiomyocytes from Klotho-deficient (kl/kl) mice and from a murine model of 5/6 nephrectomy (Nfx). We also studied the effect of exogenous Klotho supplementation, by chronic recombinant Klotho treatment, or endogenous Klotho overexpression, using transgenic mice overexpressing Klotho (Tg-Kl), on uraemic cardiomyopathy. Hearts from Nfx mice were used to study Ca2+ sensitivity of ryanodine receptors and their phosphorylation state. KEY RESULTS Cardiomyocytes from kl/kl mice showed decreased amplitude of intracellular Ca2+ transients and cellular shortening together with an increase in pro-arrhythmic Ca2+ events compared with cells from wild-type mice. Cardiomyocytes from Nfx mice exhibited the same impairment in Ca2+ cycling as kl/kl mice. Changes in Nfx cardiomyocytes were explained by higher sensitivity of ryanodine receptors to Ca2+ and their increased phosphorylation at the calmodulin kinase type II and protein kinase A sites. Ca2+ mishandling in Nfx-treated mice was fully prevented by chronic recombinant Klotho administration or transgenic Klotho overexpression. CONCLUSIONS AND IMPLICATIONS Klotho emerges as an attractive therapeutic tool to improve cardiac Ca2+ mishandling observed in uraemic cardiomyopathy. Strategies that improve Klotho availability are good candidates to protect the heart from functional cardiac alterations in renal disease.
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Affiliation(s)
- José Alberto Navarro‐García
- Cardiorenal Translational LaboratoryInstitute of Research i+12, Hospital Universitario 12 de OctubreMadridSpain
| | - Angélica Rueda
- Departamento de BioquímicaCentro de Investigación y de Estudios Avanzados del IPNMéxico CityDFMexico
| | - Tatiana Romero‐García
- Departamento de BioquímicaCentro de Investigación y de Estudios Avanzados del IPNMéxico CityDFMexico
| | - Jennifer Aceves‐Ripoll
- Cardiorenal Translational LaboratoryInstitute of Research i+12, Hospital Universitario 12 de OctubreMadridSpain
| | - Elena Rodríguez‐Sánchez
- Cardiorenal Translational LaboratoryInstitute of Research i+12, Hospital Universitario 12 de OctubreMadridSpain
| | - Laura González‐Lafuente
- Cardiorenal Translational LaboratoryInstitute of Research i+12, Hospital Universitario 12 de OctubreMadridSpain
| | - Carlos Zaragoza
- Department of CardiologyUnidad de Investigación Mixta Universidad Francisco de Vitoria/Hospital Ramon y Cajal (IRYCIS)MadridSpain
| | | | - Makoto Kuro‐o
- Division of Anti‐ageing Medicine, Centre for Molecular MedicineJichi Medical UniversityShimotsukeTochigiJapan
| | - Luis M. Ruilope
- Cardiorenal Translational LaboratoryInstitute of Research i+12, Hospital Universitario 12 de OctubreMadridSpain
- CIBER‐CVHospital Universitario 12 de OctubreMadridSpain
- School of Doctoral Studies and ResearchEuropean University of MadridMadridSpain
| | - Gema Ruiz‐Hurtado
- Cardiorenal Translational LaboratoryInstitute of Research i+12, Hospital Universitario 12 de OctubreMadridSpain
- CIBER‐CVHospital Universitario 12 de OctubreMadridSpain
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Dashwood A, Cheesman E, Beard N, Haqqani H, Wong YW, Molenaar P. Understanding How Phosphorylation and Redox Modifications Regulate Cardiac Ryanodine Receptor Type 2 Activity to Produce an Arrhythmogenic Phenotype in Advanced Heart Failure. ACS Pharmacol Transl Sci 2020; 3:563-582. [PMID: 32832863 DOI: 10.1021/acsptsci.0c00003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Indexed: 12/17/2022]
Abstract
Heart failure (HF) is a global pandemic with significant mortality and morbidity. Despite current medications, 50% of individuals die within 5 years of diagnosis. Of these deaths, 30-50% will be a result of sudden cardiac death from ventricular arrhythmias. This review discusses two stress-induced mechanisms, phosphorylation from chronic β-adrenoceptor (β-AR) stimulation and thiol modifications from oxidative stress, and how they modulate the cardiac ryanodine receptor type 2 (RyR2) and foster an arrhythmogenic phenotype. Calcium (Ca2+) is the ubiquitous secondary messenger of excitation-contraction coupling and provides a common pathway for contractile dysfunction and arrhythmia genesis. In a healthy heart, Ca2+ is released from the sarcoplasmic reticulum (SR) by RyR2. The open probability of RyR2 is under the dynamic influence of co-proteins, ions, and kinases that are in strict balance to ensure normal physiological functioning. In HF, chronic β-AR activity and production of reactive oxygen species and reactive nitrogen species provide two stress-induced mechanisms uncoupling RyR2 control, resulting in pathological diastolic SR Ca2+ leak. This increased cytosolic [Ca2+] promotes Ca2+ extrusion via the local Na+/Ca2+ exchanger, resulting in net sarcolemmal depolarization, delayed after depolarization and ventricular arrhythmia. Experimental models researching oxidative stress and phosphorylation have aimed to identify how post-translational modifications to the RyR2 macromolecular complex, and the associated Na+/Ca2+ cycling proteins, result in pathological Ca2+ handling and diastolic leak. However, the causative molecular changes remain controversial and undefined. Through understanding the molecular mechanisms that produce an arrhythmic phenotype, novel therapeutic targets to treat HF and prevent its malignant course can be identified.
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Affiliation(s)
- Alexander Dashwood
- Heart Lung Institute, The Prince Charles Hospital, Chermside, Brisbane, Queensland 4032, Australia.,Cardio-Vascular Molecular & Therapeutics Translational Research Group, Northside Clinical School of Medicine, Faculty of Medicine, University of Queensland, Brisbane, Queensland 4032, Australia.,Griffith University, Southport, Queensland 4215, Australia
| | - Elizabeth Cheesman
- Cardio-Vascular Molecular & Therapeutics Translational Research Group, Northside Clinical School of Medicine, Faculty of Medicine, University of Queensland, Brisbane, Queensland 4032, Australia
| | - Nicole Beard
- Queensland University of Technology (QUT), School of Biomedical Sciences, Institute of Health and Biomedical Innovation, 60 Musk Avenue, Kelvin Grove, Queensland 4059, Australia.,Faculty of Science and Technology, University of Canberra, Bruce, Australian Capital Territory 2617, Australia
| | - Haris Haqqani
- Heart Lung Institute, The Prince Charles Hospital, Chermside, Brisbane, Queensland 4032, Australia.,Cardio-Vascular Molecular & Therapeutics Translational Research Group, Northside Clinical School of Medicine, Faculty of Medicine, University of Queensland, Brisbane, Queensland 4032, Australia
| | - Yee Weng Wong
- Heart Lung Institute, The Prince Charles Hospital, Chermside, Brisbane, Queensland 4032, Australia.,Cardio-Vascular Molecular & Therapeutics Translational Research Group, Northside Clinical School of Medicine, Faculty of Medicine, University of Queensland, Brisbane, Queensland 4032, Australia
| | - Peter Molenaar
- Cardio-Vascular Molecular & Therapeutics Translational Research Group, Northside Clinical School of Medicine, Faculty of Medicine, University of Queensland, Brisbane, Queensland 4032, Australia.,Queensland University of Technology (QUT), School of Biomedical Sciences, Institute of Health and Biomedical Innovation, 60 Musk Avenue, Kelvin Grove, Queensland 4059, Australia
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Lee CS, Oh DE, Kim TH. Label-free assay of protein kinase A activity and inhibition in cancer cell using electrochemically-prepared AuNP/rGO nanohybrid electrode modified with C-Kemptide. Talanta 2020; 215:120899. [DOI: 10.1016/j.talanta.2020.120899] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 03/03/2020] [Accepted: 03/04/2020] [Indexed: 12/01/2022]
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Campbell HM, Quick AP, Abu-Taha I, Chiang DY, Kramm CF, Word TA, Brandenburg S, Hulsurkar M, Alsina KM, Liu HB, Martin B, Uhlenkamp D, Moore OM, Lahiri SK, Corradini E, Kamler M, Heck AJR, Lehnart SE, Dobrev D, Wehrens XHT. Loss of SPEG Inhibitory Phosphorylation of Ryanodine Receptor Type-2 Promotes Atrial Fibrillation. Circulation 2020; 142:1159-1172. [PMID: 32683896 DOI: 10.1161/circulationaha.120.045791] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Enhanced diastolic calcium (Ca2+) release through ryanodine receptor type-2 (RyR2) has been implicated in atrial fibrillation (AF) promotion. Diastolic sarcoplasmic reticulum Ca2+ leak is caused by increased RyR2 phosphorylation by PKA (protein kinase A) or CaMKII (Ca2+/calmodulin-dependent kinase-II) phosphorylation, or less dephosphorylation by protein phosphatases. However, considerable controversy remains regarding the molecular mechanisms underlying altered RyR2 function in AF. We thus aimed to determine the role of SPEG (striated muscle preferentially expressed protein kinase), a novel regulator of RyR2 phosphorylation, in AF pathogenesis. METHODS Western blotting was performed with right atrial biopsies from patients with paroxysmal AF. SPEG atrial knockout mice were generated using adeno-associated virus 9. In mice, AF inducibility was determined using intracardiac programmed electric stimulation, and diastolic Ca2+ leak in atrial cardiomyocytes was assessed using confocal Ca2+ imaging. Phosphoproteomics studies and Western blotting were used to measure RyR2 phosphorylation. To test the effects of RyR2-S2367 phosphorylation, knockin mice with an inactivated S2367 phosphorylation site (S2367A) and a constitutively activated S2367 residue (S2367D) were generated by using CRISPR-Cas9. RESULTS Western blotting revealed decreased SPEG protein levels in atrial biopsies from patients with paroxysmal AF in comparison with patients in sinus rhythm. SPEG atrial-specific knockout mice exhibited increased susceptibility to pacing-induced AF by programmed electric stimulation and enhanced Ca2+ spark frequency in atrial cardiomyocytes with Ca2+ imaging, establishing a causal role for decreased SPEG in AF pathogenesis. Phosphoproteomics in hearts from SPEG cardiomyocyte knockout mice identified RyR2-S2367 as a novel kinase substrate of SPEG. Western blotting demonstrated that RyR2-S2367 phosphorylation was also decreased in patients with paroxysmal AF. RyR2-S2367A mice exhibited an increased susceptibility to pacing-induced AF, and aberrant atrial sarcoplasmic reticulum Ca2+ leak, as well. In contrast, RyR2-S2367D mice were resistant to pacing-induced AF. CONCLUSIONS Unlike other kinases (PKA, CaMKII) that increase RyR2 activity, SPEG phosphorylation reduces RyR2-mediated sarcoplasmic reticulum Ca2+ release. Reduced SPEG levels and RyR2-S2367 phosphorylation typified patients with paroxysmal AF. Studies in S2367 knockin mouse models showed a causal relationship between reduced S2367 phosphorylation and AF susceptibility. Thus, modulating SPEG activity and phosphorylation levels of the novel S2367 site on RyR2 may represent a novel target for AF treatment.
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Affiliation(s)
- Hannah M Campbell
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Molecular Physiology & Biophysics (H.M.C., A.P.Q., D.Y.C., F.K., T.A.W., M.H., K.M.A., H.-L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX
| | - Ann P Quick
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Molecular Physiology & Biophysics (H.M.C., A.P.Q., D.Y.C., F.K., T.A.W., M.H., K.M.A., H.-L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX
| | - Issam Abu-Taha
- Institute of Pharmacology (I.A.-T., D.D.), University Duisburg-Essen, Germany
| | - David Y Chiang
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Molecular Physiology & Biophysics (H.M.C., A.P.Q., D.Y.C., F.K., T.A.W., M.H., K.M.A., H.-L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Medicine (Cardiovascular Division), Brigham and Women's Hospital, Harvard Medical School, Boston, MA (D.Y.C.)
| | - Carlos F Kramm
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX
| | - Tarah A Word
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Molecular Physiology & Biophysics (H.M.C., A.P.Q., D.Y.C., F.K., T.A.W., M.H., K.M.A., H.-L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX
| | - Sören Brandenburg
- Heart Research Center Göttingen, Department of Cardiology & Pneumology, University Medical Center Göttingen, Germany (S.B., D.U., S.E.L.)
| | - Mohit Hulsurkar
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Molecular Physiology & Biophysics (H.M.C., A.P.Q., D.Y.C., F.K., T.A.W., M.H., K.M.A., H.-L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX
| | - Katherina M Alsina
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Molecular Physiology & Biophysics (H.M.C., A.P.Q., D.Y.C., F.K., T.A.W., M.H., K.M.A., H.-L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX
| | - Hui-Bin Liu
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Molecular Physiology & Biophysics (H.M.C., A.P.Q., D.Y.C., F.K., T.A.W., M.H., K.M.A., H.-L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Institute of Clinical Pharmacy, the Second Affiliated Hospital of Harbin Medical University, China (H.-B.L.)
| | - Brian Martin
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Molecular Physiology & Biophysics (H.M.C., A.P.Q., D.Y.C., F.K., T.A.W., M.H., K.M.A., H.-L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX
| | - Dennis Uhlenkamp
- Institute of Pharmacology (I.A.-T., D.D.), University Duisburg-Essen, Germany.,Heart Research Center Göttingen, Department of Cardiology & Pneumology, University Medical Center Göttingen, Germany (S.B., D.U., S.E.L.)
| | - Oliver M Moore
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Neuroscience (O.M.M., X.H.T.W.), Baylor College of Medicine, Houston, TX
| | - Satadru K Lahiri
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX
| | - Eleonora Corradini
- Biomolecular Mass Spectrometry & Proteomics, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, The Netherlands (E.C., A.J.R.H.)
| | - Markus Kamler
- Department of Thoracic and Cardiovascular Surgery Huttrop (M.K.), University Duisburg-Essen, Germany
| | - Albert J R Heck
- Biomolecular Mass Spectrometry & Proteomics, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, The Netherlands (E.C., A.J.R.H.)
| | - Stephan E Lehnart
- Heart Research Center Göttingen, Department of Cardiology & Pneumology, University Medical Center Göttingen, Germany (S.B., D.U., S.E.L.)
| | | | - Xander H T Wehrens
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Molecular Physiology & Biophysics (H.M.C., A.P.Q., D.Y.C., F.K., T.A.W., M.H., K.M.A., H.-L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Neuroscience (O.M.M., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Medicine (Cardiology) (X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Pediatrics (X.H.T.W.), Baylor College of Medicine, Houston, TX.,Center for Space Medicine (X.H.T.W.), Baylor College of Medicine, Houston, TX
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Intracellular calcium leak in heart failure and atrial fibrillation: a unifying mechanism and therapeutic target. Nat Rev Cardiol 2020; 17:732-747. [PMID: 32555383 DOI: 10.1038/s41569-020-0394-8] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/06/2020] [Indexed: 12/14/2022]
Abstract
Ca2+ is a fundamental second messenger in all cell types and is required for numerous essential cellular functions, including cardiac and skeletal muscle contraction. The intracellular concentration of free Ca2+ ([Ca2+]) is regulated primarily by ion channels, pumps (ATPases), exchangers and Ca2+-binding proteins. Defective regulation of [Ca2+] is found in a diverse spectrum of pathological states that affect all the major organs. In the heart, abnormalities in the regulation of cytosolic and mitochondrial [Ca2+] occur in heart failure (HF) and atrial fibrillation (AF), two common forms of heart disease and leading contributors to morbidity and mortality. In this Review, we focus on the mechanisms that regulate ryanodine receptor 2 (RYR2), the major sarcoplasmic reticulum (SR) Ca2+-release channel in the heart, how RYR2 becomes dysfunctional in HF and AF, and its potential as a therapeutic target. Inherited RYR2 mutations and/or stress-induced phosphorylation and oxidation of the protein destabilize the closed state of the channel, resulting in a pathological diastolic Ca2+ leak from the SR that both triggers arrhythmias and impairs contractility. On the basis of our increased understanding of SR Ca2+ leak as a shared Ca2+-dependent pathological mechanism in HF and AF, a new class of drugs developed in our laboratory, known as rycals, which stabilize RYR2 channels and prevent Ca2+ leak from the SR, are undergoing investigation in clinical trials.
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Potenza DM, Janicek R, Fernandez-Tenorio M, Niggli E. Activation of endogenous protein phosphatase 1 enhances the calcium sensitivity of the ryanodine receptor type 2 in murine ventricular cardiomyocytes. J Physiol 2020; 598:1131-1150. [PMID: 31943206 DOI: 10.1113/jp278951] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 01/10/2020] [Indexed: 01/23/2023] Open
Abstract
KEY POINTS Increased protein phosphatase 1 (PP-1) activity has been found in end stage human heart failure. Although PP-1 has been extensively studied, a detailed understanding of its role in the excitation-contraction coupling mechanism, in normal and diseased hearts, remains elusive. The present study investigates the functional effect of the PP-1 activity on local Ca2+ release events in ventricular cardiomyocytes, by using an activating peptide (PDP3) for the stimulation of the endogenous PP-1 protein. We report that acute de-phosphorylation may increase the sensitivity of RyR2 channels to Ca2+ in situ, and that the RyR2-serine2808 phosphorylation site may mediate such a process. Our approach unmasks the functional importance of PP-1 in the regulation of RyR2 activity, suggesting a potential role in the generation of a pathophysiological sarcoplasmic reticulum Ca2+ leak in the diseased heart. ABSTRACT Changes in cardiac ryanodine receptor (RyR2) phosphorylation are considered to be important regulatory and disease related post-translational protein modifications. The extent of RyR2 phosphorylation is mainly determined by the balance of the activities of protein kinases and phosphatases, respectively. Increased protein phosphatase-1 (PP-1) activity has been observed in heart failure, although the regulatory role of this enzyme on intracellular Ca2+ handling remains poorly understood. To determine the physiological and pathophysiological significance of increased PP-1 activity, we investigated how the PP-1 catalytic subunit (PP-1c) alters Ca2+ sparks in permeabilized cardiomyocytes and we also applied a PP-1-disrupting peptide (PDP3) to specifically activate endogenous PP-1, including the one anchored on the RyR2 macromolecular complex. We compared wild-type and transgenic mice in which the usually highly phosphorylated site RyR2-S2808 has been ablated to investigate its involvement in RyR2 modulation (S2808A+/+ ). In wild-type myocytes, PP-1 increased Ca2+ spark frequency by two-fold, followed by depletion of the sarcoplasmic reticulum Ca2+ store. Similarly, PDP3 transiently increased spark frequency and decreased sarcoplasmic reticulum Ca2+ load. RyR2 Ca2+ sensitivity, which was assessed by Ca2+ spark recovery analysis, was increased in the presence of PDP3 compared to a negative control peptide. S2808A+/+ cardiomyocytes did not respond to both PP-1c and PDP3 treatment. Our results suggest an increased Ca2+ sensitivity of RyR2 upon de-phosphorylation by PP-1. Furthermore, we have confirmed the S2808 site as a target for PP-1 and as a potential link between RyR2s modulation and the cellular response.
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Affiliation(s)
| | | | | | - Ernst Niggli
- Department of Physiology, University of Bern, Bern, Switzerland
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28
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Federico M, Valverde CA, Mattiazzi A, Palomeque J. Unbalance Between Sarcoplasmic Reticulum Ca 2 + Uptake and Release: A First Step Toward Ca 2 + Triggered Arrhythmias and Cardiac Damage. Front Physiol 2020; 10:1630. [PMID: 32038301 PMCID: PMC6989610 DOI: 10.3389/fphys.2019.01630] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 12/24/2019] [Indexed: 12/19/2022] Open
Abstract
The present review focusses on the regulation and interplay of cardiac SR Ca2+ handling proteins involved in SR Ca2+ uptake and release, i.e., SERCa2/PLN and RyR2. Both RyR2 and SERCA2a/PLN are highly regulated by post-translational modifications and/or different partners' proteins. These control mechanisms guarantee a precise equilibrium between SR Ca2+ reuptake and release. The review then discusses how disruption of this balance alters SR Ca2+ handling and may constitute a first step toward cardiac damage and malignant arrhythmias. In the last part of the review, this concept is exemplified in different cardiac diseases, like prediabetic and diabetic cardiomyopathy, digitalis intoxication and ischemia-reperfusion injury.
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Affiliation(s)
- Marilén Federico
- Centro de Investigaciones Cardiovasculares "Dr. Horacio E. Cingolani", CCT-La Plata/CONICET, Facultad de Cs. Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Carlos A Valverde
- Centro de Investigaciones Cardiovasculares "Dr. Horacio E. Cingolani", CCT-La Plata/CONICET, Facultad de Cs. Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Alicia Mattiazzi
- Centro de Investigaciones Cardiovasculares "Dr. Horacio E. Cingolani", CCT-La Plata/CONICET, Facultad de Cs. Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Julieta Palomeque
- Centro de Investigaciones Cardiovasculares "Dr. Horacio E. Cingolani", CCT-La Plata/CONICET, Facultad de Cs. Médicas, Universidad Nacional de La Plata, La Plata, Argentina.,Centro de Altos Estudios en Ciencias Humanas y de la Salud, Universidad Abierta Interamericana, Buenos Aires, Argentina
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Asghari P, Scriven DR, Ng M, Panwar P, Chou KC, van Petegem F, Moore ED. Cardiac ryanodine receptor distribution is dynamic and changed by auxiliary proteins and post-translational modification. eLife 2020; 9:51602. [PMID: 31916935 PMCID: PMC6994221 DOI: 10.7554/elife.51602] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 01/09/2020] [Indexed: 12/14/2022] Open
Abstract
The effects of the immunophilins, FKBP12 and FKBP12.6, and phosphorylation on type II ryanodine receptor (RyR2) arrangement and function were examined using correlation microscopy (line scan confocal imaging of Ca2+ sparks and dual-tilt electron tomography) and dSTORM imaging of permeabilized Wistar rat ventricular myocytes. Saturating concentrations (10 µmol/L) of either FKBP12 or 12.6 significantly reduced the frequency, spread, amplitude and Ca2+ spark mass relative to control, while the tomograms revealed both proteins shifted the tetramers into a largely side-by-side configuration. Phosphorylation of immunophilin-saturated RyR2 resulted in structural and functional changes largely comparable to phosphorylation alone. dSTORM images of myocyte surfaces demonstrated that both FKBP12 and 12.6 significantly reduced RyR2 cluster sizes, while phosphorylation, even of immunophilin-saturated RyR2, increased them. We conclude that both RyR2 cluster size and the arrangement of tetramers within clusters is dynamic and respond to changes in the cellular environment. Further, these changes affect Ca2+ spark formation.
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Affiliation(s)
- Parisa Asghari
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - David Rl Scriven
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - Myles Ng
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - Pankaj Panwar
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
| | - Keng C Chou
- Department of Chemistry, University of British Columbia, Vancouver, Canada
| | - Filip van Petegem
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
| | - Edwin Dw Moore
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
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Søndergaard MT, Liu Y, Guo W, Wei J, Wang R, Brohus M, Overgaard MT, Chen SRW. Role of cardiac ryanodine receptor calmodulin-binding domains in mediating the action of arrhythmogenic calmodulin N-domain mutation N54I. FEBS J 2019; 287:2256-2280. [PMID: 31763755 DOI: 10.1111/febs.15147] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 09/12/2019] [Accepted: 11/19/2019] [Indexed: 11/27/2022]
Abstract
The Ca2+ -sensing protein calmodulin (CaM) inhibits cardiac ryanodine receptor (RyR2)-mediated Ca2+ release. CaM mutations associated with arrhythmias and sudden cardiac death have been shown to diminish CaM-dependent inhibition of RyR2, but the underlying mechanisms are not well understood. Nearly all arrhythmogenic CaM mutations identified are located in the C-domain of CaM and exert marked effects on Ca2+ binding to CaM and on the CaM C-domain interaction with the CaM-binding domain 2 (CaMBD2) in RyR2. Interestingly, the arrhythmogenic N-domain mutation CaM-N54I has little or no effect on Ca2+ binding to CaM or the CaM C-domain-RyR2 CaMBD2 interaction, unlike all CaM C-domain mutations. This suggests that CaM-N54I may diminish CaM-dependent RyR2 inhibition by affecting CaM N-domain interactions with RyR2 CaMBDs other than CaMBD2. To explore this possibility, we assessed the effects of deleting each of the four known CaMBDs in RyR2 (CaMBD1a, -1b, -2, or -3) on the CaM-dependent inhibition of RyR2-mediated Ca2+ release in HEK293 cells. We found that removing CaMBD1a, CaMBD1b, or CaMBD3 did not alter the effects of CaM-N54I or CaM-WT on RyR2 inhibition. On the other hand, deleting RyR2-CaMBD2 abolished the effects of both CaM-N54I and CaM-WT. Our results support that CaM-N54I causes aberrant RyR2 regulation via an uncharacterized CaMBD or less likely CaMBD2, and that RyR2 CaMBD2 is required for the actions of both N- and C-domain CaM mutations. Moreover, our results show that CaMBD1a is central to RyR2 regulation, but CaMBD1a, CaMBD1b, and CaMBD3 are not required for CaM-dependent inhibition of RyR2 in HEK293 cells.
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Affiliation(s)
- Mads T Søndergaard
- Department of Chemistry and Bioscience, Aalborg University, Denmark.,Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, AB, Canada
| | - Yingjie Liu
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, AB, Canada
| | - Wenting Guo
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, AB, Canada
| | - Jinhong Wei
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, AB, Canada
| | - Ruiwu Wang
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, AB, Canada
| | - Malene Brohus
- Department of Chemistry and Bioscience, Aalborg University, Denmark
| | | | - S R Wayne Chen
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, AB, Canada
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Xu T, Yuchi Z. Crystal structure of diamondback moth ryanodine receptor Repeat34 domain reveals insect-specific phosphorylation sites. BMC Biol 2019; 17:77. [PMID: 31597572 PMCID: PMC6784350 DOI: 10.1186/s12915-019-0698-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 09/02/2019] [Indexed: 01/23/2023] Open
Abstract
Background Ryanodine receptor (RyR), a calcium-release channel located in the sarcoplasmic reticulum membrane of muscles, is the target of insecticides used against a wide range of agricultural pests. Mammalian RyRs have been shown to be under the regulatory control of several kinases and phosphatases, but little is known about the regulation of insect RyRs by phosphorylation. Results Here we present the crystal structures of wild-type and phospho-mimetic RyR Repeat34 domain containing PKA phosphorylation sites from diamondback moth (DBM), a major lepidopteran pest of cruciferous vegetables. The structure has unique features, not seen in mammalian RyRs, including an additional α-helix near the phosphorylation loop. Using tandem mass spectrometry, we identify several PKA sites clustering in the phosphorylation loop and the newly identified α-helix. Bioinformatics analysis shows that this α-helix is only present in Lepidoptera, suggesting an insect-specific regulation. Interestingly, the specific phosphorylation pattern is temperature-dependent. The thermal stability of the DBM Repeat34 domain is significantly lower than that of the analogous domain in the three mammalian RyR isoforms, indicating a more dynamic domain structure that can be partially unfolded to facilitate the temperature-dependent phosphorylation. Docking the structure into the cryo-electron microscopy model of full-length RyR reveals that the interface between the Repeat34 and neighboring HD1 domain is more conserved than that of the phosphorylation loop region that might be involved in the interaction with SPRY3 domain. We also identify an insect-specific glycerol-binding pocket that could be potentially targeted by novel insecticides to fight the current resistance crisis. Conclusions The crystal structures of the DBM Repeat34 domain reveals insect-specific temperature-dependent phosphorylation sites that may regulate insect ryanodine receptor function. It also reveals insect-specific structural features and a potential ligand-binding site that could be targeted in an effort to develop green pesticides with high species-specificity.
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Affiliation(s)
- Tong Xu
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, China
| | - Zhiguang Yuchi
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, China.
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32
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Modulation of cardiac ryanodine receptor 2 by calmodulin. Nature 2019; 572:347-351. [PMID: 31278385 DOI: 10.1038/s41586-019-1377-y] [Citation(s) in RCA: 91] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Accepted: 06/04/2019] [Indexed: 11/08/2022]
Abstract
The high-conductance intracellular calcium (Ca2+) channel RyR2 is essential for the coupling of excitation and contraction in cardiac muscle. Among various modulators, calmodulin (CaM) regulates RyR2 in a Ca2+-dependent manner. Here we reveal the regulatory mechanism by which porcine RyR2 is modulated by human CaM through the structural determination of RyR2 under eight conditions. Apo-CaM and Ca2+-CaM bind to distinct but overlapping sites in an elongated cleft formed by the handle, helical and central domains. The shift in CaM-binding sites on RyR2 is controlled by Ca2+ binding to CaM, rather than to RyR2. Ca2+-CaM induces rotations and intradomain shifts of individual central domains, resulting in pore closure of the PCB95 and Ca2+-activated channel. By contrast, the pore of the ATP, caffeine and Ca2+-activated channel remains open in the presence of Ca2+-CaM, which suggests that Ca2+-CaM is one of the many competing modulators of RyR2 gating.
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Haji-Ghassemi O, Yuchi Z, Van Petegem F. The Cardiac Ryanodine Receptor Phosphorylation Hotspot Embraces PKA in a Phosphorylation-Dependent Manner. Mol Cell 2019; 75:39-52.e4. [PMID: 31078384 DOI: 10.1016/j.molcel.2019.04.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 03/05/2019] [Accepted: 04/11/2019] [Indexed: 12/22/2022]
Abstract
Ryanodine receptors (RyRs) are intracellular Ca2+ release channels controlling essential cellular functions. RyRs are targeted by cyclic AMP (cAMP)-dependent protein kinase A (PKA), a controversial regulation implicated in disorders ranging from heart failure to Alzheimer's. Using crystal structures, we show that the phosphorylation hotspot domain of RyR2 embraces the PKA catalytic subunit, with an extensive interface not seen in PKA complexes with peptides. We trapped an intermediary open-form PKA bound to the RyR2 domain and an ATP analog, showing that PKA can engage substrates in an open form. Phosphomimetics or prior phosphorylation at nearby sites in RyR2 either enhance or reduce the activity of PKA. Finally, we show that a phosphomimetic at S2813, a well-known target site for calmodulin-dependent kinase II, induces the formation of an alpha helix in the phosphorylation domain, resulting in increased interactions and PKA activity. This shows that the different phosphorylation sites in RyR2 are not independent.
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Affiliation(s)
- Omid Haji-Ghassemi
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Zhiguang Yuchi
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
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Walweel K, Gomez-Hurtado N, Rebbeck RT, Oo YW, Beard NA, Molenaar P, Dos Remedios C, van Helden DF, Cornea RL, Knollmann BC, Laver DR. Calmodulin inhibition of human RyR2 channels requires phosphorylation of RyR2-S2808 or RyR2-S2814. J Mol Cell Cardiol 2019; 130:96-106. [PMID: 30928430 DOI: 10.1016/j.yjmcc.2019.03.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 02/19/2019] [Accepted: 03/25/2019] [Indexed: 01/08/2023]
Abstract
Calmodulin (CaM) is a Ca-binding protein that binds to, and can directly inhibit cardiac ryanodine receptor calcium release channels (RyR2). Animal studies have shown that RyR2 hyperphosphorylation reduces CaM binding to RyR2 in failing hearts, but data are lacking on how CaM regulates human RyR2 and how this regulation is affected by RyR2 phosphorylation. Physiological concentrations of CaM (100 nM) inhibited the diastolic activity of RyR2 isolated from failing human hearts by ~50% but had no effect on RyR2 from healthy human hearts. Using FRET between donor-FKBP12.6 and acceptor-CaM bound to RyR2, we determined that CaM binds to RyR2 from healthy human heart with a Kd = 121 ± 14 nM. Ex-vivo phosphorylation/dephosphorylation experiments suggested that the divergent CaM regulation of healthy and failing human RyR2 was caused by differences in RyR2 phosphorylation by protein kinase A and Ca-CaM-dependent kinase II. Ca2+-spark measurements in murine cardiomyocytes harbouring RyR2 phosphomimetic or phosphoablated mutants at S2814 and S2808 suggest that phosphorylation of residues corresponding to either human RyR2-S2808 or S2814 is both necessary and sufficient for RyR2 regulation by CaM. Our results challenge the current concept that CaM universally functions as a canonical inhibitor of RyR2 across species. Rather, CaM's biological action on human RyR2 appears to be more nuanced, with inhibitory activity only on phosphorylated RyR2 channels, which occurs during exercise or in patients with heart failure.
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Affiliation(s)
- Kafa Walweel
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, NSW 2308, Australia.
| | - Nieves Gomez-Hurtado
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
| | - Robyn T Rebbeck
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.
| | - Ye Wint Oo
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, NSW 2308, Australia
| | - Nicole A Beard
- Faculty of Science and Technology, University of Canberra, Bruce, ACT 2617, Australia.
| | - Peter Molenaar
- School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD 4000, Australia; Northside Clinical School of Medicine, University of Queensland, Cardio-vascular Molecular & Therapeutics Translational Research Group, The Prince Charles Hospital, Chermside, QLD 4032. Australia.
| | - Cris Dos Remedios
- Bosch Institute, Discipline of Anatomy, University of Sydney, Sydney, New South Wales 2006, Australia.
| | - Dirk F van Helden
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, NSW 2308, Australia.
| | - Razvan L Cornea
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.
| | - Björn C Knollmann
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
| | - Derek R Laver
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, NSW 2308, Australia.
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35
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Ca 2+-dependent calmodulin binding to cardiac ryanodine receptor (RyR2) calmodulin-binding domains. Biochem J 2019; 476:193-209. [PMID: 30530841 PMCID: PMC6340113 DOI: 10.1042/bcj20180545] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 12/05/2018] [Accepted: 12/10/2018] [Indexed: 12/17/2022]
Abstract
The Ca2+ sensor calmodulin (CaM) regulates cardiac ryanodine receptor (RyR2)-mediated Ca2+ release from the sarcoplasmic reticulum. CaM inhibits RyR2 in a Ca2+-dependent manner and aberrant CaM-dependent inhibition results in life-threatening cardiac arrhythmias. However, the molecular details of the CaM–RyR2 interaction remain unclear. Four CaM-binding domains (CaMBD1a, -1b, -2, and -3) in RyR2 have been proposed. Here, we investigated the Ca2+-dependent interactions between CaM and these CaMBDs by monitoring changes in the fluorescence anisotropy of carboxytetramethylrhodamine (TAMRA)-labeled CaMBD peptides during titration with CaM at a wide range of Ca2+ concentrations. We showed that CaM bound to all four CaMBDs with affinities that increased with Ca2+ concentration. CaM bound to CaMBD2 and -3 with high affinities across all Ca2+ concentrations tested, but bound to CaMBD1a and -1b only at Ca2+ concentrations above 0.2 µM. Binding experiments using individual CaM domains revealed that the CaM C-domain preferentially bound to CaMBD2, and the N-domain to CaMBD3. Moreover, the Ca2+ affinity of the CaM C-domain in complex with CaMBD2 or -3 was so high that these complexes are essentially Ca2+ saturated under resting Ca2+ conditions. Conversely, the N-domain senses Ca2+ exactly in the transition from resting to activating Ca2+ when complexed to either CaMBD2 or -3. Altogether, our results support a binding model where the CaM C-domain is anchored to RyR2 CaMBD2 and saturated with Ca2+ during Ca2+ oscillations, while the CaM N-domain functions as a dynamic Ca2+ sensor that can bridge noncontiguous regions of RyR2 or clamp down onto CaMBD2.
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36
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Potenza DM, Janicek R, Fernandez-Tenorio M, Camors E, Ramos-Mondragón R, Valdivia HH, Niggli E. Phosphorylation of the ryanodine receptor 2 at serine 2030 is required for a complete β-adrenergic response. J Gen Physiol 2018; 151:131-145. [PMID: 30541771 PMCID: PMC6363414 DOI: 10.1085/jgp.201812155] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 08/12/2018] [Accepted: 10/22/2018] [Indexed: 11/20/2022] Open
Abstract
Phosphorylation is thought to play a role in modulation of the ryanodine receptor 2 channel. Using a S2030A knock-in mouse model, Potenza et al. reveal that phosphorylation of RyR2-S2030 mediates channel regulation during the β-adrenergic response. During physical exercise or stress, the sympathetic system stimulates cardiac contractility via β-adrenergic receptor (β-AR) activation, resulting in protein kinase A (PKA)–mediated phosphorylation of the cardiac ryanodine receptor RyR2. PKA-dependent “hyperphosphorylation” of the RyR2 channel has been proposed as a major impairment that contributes to progression of heart failure. However, the sites of PKA phosphorylation and their phosphorylation status in cardiac diseases are not well defined. Among the known RyR2 phosphorylation sites, serine 2030 (S2030) remains highly controversial as a site of functional impact. We examined the contribution of RyR2-S2030 to Ca2+ signaling and excitation–contraction coupling (ECC) in a transgenic mouse with an ablated RyR2-S2030 phosphorylation site (RyR2-S2030A+/+). We assessed ECC gain by using whole-cell patch–clamp recordings and confocal Ca2+ imaging during β-ARs stimulation with isoproterenol (Iso) and consistent SR Ca2+ loading and L-type Ca2+ current (ICa) triggering. Under these conditions, ECC gain is diminished in mutant compared with WT cardiomyocytes. Resting Ca2+ spark frequency (CaSpF) with Iso is also reduced by mutation of S2030. In permeabilized cells, when SR Ca2+ pump activity is kept constant (using 2D12 antibody against phospholamban), cAMP does not change CaSpF in S2030A+/+ myocytes. Using Ca2+ spark recovery analysis, we found that mutant RyR Ca2+ sensitivity is not enhanced by Iso application, contrary to WT RyRs. Furthermore, ablation of RyR2-S2030 prevents acceleration of Ca2+ waves and increases latency to the first spontaneous Ca2+ release after a train of stimulations during Iso treatment. Together, these results suggest that phosphorylation at S2030 may represent an important step in the modulation of RyR2 activity during β-adrenergic stimulation and a potential target for the development of new antiarrhythmic drugs.
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Affiliation(s)
| | | | | | - Emmanuel Camors
- Center for Arrhythmia Research, Department of Medicine, University of Michigan, Ann Arbor, MI
| | - Roberto Ramos-Mondragón
- Center for Arrhythmia Research, Department of Medicine, University of Michigan, Ann Arbor, MI
| | - Héctor H Valdivia
- Department of Medicine, Wisconsin Institutes for Medical Research, University of Wisconsin, Madison, WI.,Center for Arrhythmia Research, Department of Medicine, University of Michigan, Ann Arbor, MI
| | - Ernst Niggli
- Department of Physiology, University of Bern, Bern, Switzerland
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37
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Hamilton S, Terentyev D. Proarrhythmic Remodeling of Calcium Homeostasis in Cardiac Disease; Implications for Diabetes and Obesity. Front Physiol 2018. [PMID: 30425651 DOI: 10.3389/fphys.2018.01517, 10.3389/fpls.2018.01517] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A rapid growth in the incidence of diabetes and obesity has transpired to a major heath issue and economic burden in the postindustrial world, with more than 29 million patients affected in the United States alone. Cardiovascular defects have been established as the leading cause of mortality and morbidity of diabetic patients. Over the last decade, significant progress has been made in delineating mechanisms responsible for the diminished cardiac contractile function and enhanced propensity for malignant cardiac arrhythmias characteristic of diabetic disease. Rhythmic cardiac contractility relies upon the precise interplay between several cellular Ca2+ transport protein complexes including plasmalemmal L-type Ca2+ channels (LTCC), Na+-Ca2+ exchanger (NCX1), Sarco/endoplasmic Reticulum (SR) Ca2+-ATPase (SERCa2a) and ryanodine receptors (RyR2s), the SR Ca2+ release channels. Here we provide an overview of changes in Ca2+ homeostasis in diabetic ventricular myocytes and discuss the therapeutic potential of targeting Ca2+ handling proteins in the prevention of diabetes-associated cardiomyopathy and arrhythmogenesis.
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Affiliation(s)
- Shanna Hamilton
- Department of Medicine, The Warren Alpert Medical School of Brown University, Providence, RI, United States.,Cardiovascular Research Center, Rhode Island Hospital, Providence, RI, United States
| | - Dmitry Terentyev
- Department of Medicine, The Warren Alpert Medical School of Brown University, Providence, RI, United States.,Cardiovascular Research Center, Rhode Island Hospital, Providence, RI, United States
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38
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Hamilton S, Terentyev D. Proarrhythmic Remodeling of Calcium Homeostasis in Cardiac Disease; Implications for Diabetes and Obesity. Front Physiol 2018; 9:1517. [PMID: 30425651 PMCID: PMC6218530 DOI: 10.3389/fphys.2018.01517] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 10/09/2018] [Indexed: 12/28/2022] Open
Abstract
A rapid growth in the incidence of diabetes and obesity has transpired to a major heath issue and economic burden in the postindustrial world, with more than 29 million patients affected in the United States alone. Cardiovascular defects have been established as the leading cause of mortality and morbidity of diabetic patients. Over the last decade, significant progress has been made in delineating mechanisms responsible for the diminished cardiac contractile function and enhanced propensity for malignant cardiac arrhythmias characteristic of diabetic disease. Rhythmic cardiac contractility relies upon the precise interplay between several cellular Ca2+ transport protein complexes including plasmalemmal L-type Ca2+ channels (LTCC), Na+-Ca2+ exchanger (NCX1), Sarco/endoplasmic Reticulum (SR) Ca2+-ATPase (SERCa2a) and ryanodine receptors (RyR2s), the SR Ca2+ release channels. Here we provide an overview of changes in Ca2+ homeostasis in diabetic ventricular myocytes and discuss the therapeutic potential of targeting Ca2+ handling proteins in the prevention of diabetes-associated cardiomyopathy and arrhythmogenesis.
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Affiliation(s)
- Shanna Hamilton
- Department of Medicine, The Warren Alpert Medical School of Brown University, Providence, RI, United States.,Cardiovascular Research Center, Rhode Island Hospital, Providence, RI, United States
| | - Dmitry Terentyev
- Department of Medicine, The Warren Alpert Medical School of Brown University, Providence, RI, United States.,Cardiovascular Research Center, Rhode Island Hospital, Providence, RI, United States
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39
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Meissner G. The structural basis of ryanodine receptor ion channel function. J Gen Physiol 2017; 149:1065-1089. [PMID: 29122978 PMCID: PMC5715910 DOI: 10.1085/jgp.201711878] [Citation(s) in RCA: 147] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 10/12/2017] [Indexed: 01/25/2023] Open
Abstract
Large-conductance Ca2+ release channels known as ryanodine receptors (RyRs) mediate the release of Ca2+ from an intracellular membrane compartment, the endo/sarcoplasmic reticulum. There are three mammalian RyR isoforms: RyR1 is present in skeletal muscle; RyR2 is in heart muscle; and RyR3 is expressed at low levels in many tissues including brain, smooth muscle, and slow-twitch skeletal muscle. RyRs form large protein complexes comprising four 560-kD RyR subunits, four ∼12-kD FK506-binding proteins, and various accessory proteins including calmodulin, protein kinases, and protein phosphatases. RyRs share ∼70% sequence identity, with the greatest sequence similarity in the C-terminal region that forms the transmembrane, ion-conducting domain comprising ∼500 amino acids. The remaining ∼4,500 amino acids form the large regulatory cytoplasmic "foot" structure. Experimental evidence for Ca2+, ATP, phosphorylation, and redox-sensitive sites in the cytoplasmic structure have been described. Exogenous effectors include the two Ca2+ releasing agents caffeine and ryanodine. Recent work describing the near atomic structures of mammalian skeletal and cardiac muscle RyRs provides a structural basis for the regulation of the RyRs by their multiple effectors.
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Affiliation(s)
- Gerhard Meissner
- Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina, Chapel Hill, NC
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40
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Jones PP, Guo W, Chen SRW. Control of cardiac ryanodine receptor by sarcoplasmic reticulum luminal Ca 2. J Gen Physiol 2017; 149:867-875. [PMID: 28798281 PMCID: PMC5583710 DOI: 10.1085/jgp.201711805] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 06/25/2017] [Accepted: 07/18/2017] [Indexed: 12/22/2022] Open
Abstract
Jones et al. propose that SR luminal Ca2+ regulates RyR2 activity via a luminal Ca2+ sensor distinct from the cytosolic Ca2+ sensor.
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Affiliation(s)
- Peter P Jones
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, Otago, New Zealand .,HeartOtago, University of Otago, Dunedin, Otago, New Zealand
| | - Wenting Guo
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - S R Wayne Chen
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
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41
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Gonano LA, Jones PP. FK506-binding proteins 12 and 12.6 (FKBPs) as regulators of cardiac Ryanodine Receptors: Insights from new functional and structural knowledge. Channels (Austin) 2017. [PMID: 28636428 DOI: 10.1080/19336950.2017.1344799] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Ryanodine Receptors (RyRs) are intracellular Ca2+ channels that mediate Ca2+ flux from the sarco(endo)plasmic reticulum in many cell types. The interaction of RyRs with FK506-binding proteins (FKBPs) has been proposed as an important regulatory mechanism, where the loss of this interaction leads to channel dysfunction. In the heart, phosphorylation of RyR has been suggested to disrupt the RyR-FKBP interaction promoting altered Ca2+ signaling, heart failure and arrhythmias. However, the functional result of FKBP interaction with RyR and how this interaction is regulated remains highly controversial. Recently, high resolution structures of RyR have provided novel aspects to the ongoing debate. This review will discuss the most recent functional data in light of these new structures.
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Affiliation(s)
- Luis A Gonano
- a Department of Physiology , School of Biomedical Sciences and HeartOtago, University of Otago , Dunedin, Otago , New Zealand
| | - Peter P Jones
- a Department of Physiology , School of Biomedical Sciences and HeartOtago, University of Otago , Dunedin, Otago , New Zealand
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42
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Reilly-O'Donnell B, Robertson GB, Karumbi A, McIntyre C, Bal W, Nishi M, Takeshima H, Stewart AJ, Pitt SJ. Dysregulated Zn 2+ homeostasis impairs cardiac type-2 ryanodine receptor and mitsugumin 23 functions, leading to sarcoplasmic reticulum Ca 2+ leakage. J Biol Chem 2017. [PMID: 28630041 PMCID: PMC5555195 DOI: 10.1074/jbc.m117.781708] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Aberrant Zn2+ homeostasis is associated with dysregulated intracellular Ca2+ release, resulting in chronic heart failure. In the failing heart a small population of cardiac ryanodine receptors (RyR2) displays sub-conductance-state gating leading to Ca2+ leakage from sarcoplasmic reticulum (SR) stores, which impairs cardiac contractility. Previous evidence suggests contribution of RyR2-independent Ca2+ leakage through an uncharacterized mechanism. We sought to examine the role of Zn2+ in shaping intracellular Ca2+ release in cardiac muscle. Cardiac SR vesicles prepared from sheep or mouse ventricular tissue were incorporated into phospholipid bilayers under voltage-clamp conditions, and the direct action of Zn2+ on RyR2 channel function was examined. Under diastolic conditions, the addition of pathophysiological concentrations of Zn2+ (≥2 nm) caused dysregulated RyR2-channel openings. Our data also revealed that RyR2 channels are not the only SR Ca2+-permeable channels regulated by Zn2+. Elevating the cytosolic Zn2+ concentration to 1 nm increased the activity of the transmembrane protein mitsugumin 23 (MG23). The current amplitude of the MG23 full-open state was consistent with that previously reported for RyR2 sub-conductance gating, suggesting that in heart failure in which Zn2+ levels are elevated, RyR2 channels do not gate in a sub-conductance state, but rather MG23-gating becomes more apparent. We also show that in H9C2 cells exposed to ischemic conditions, intracellular Zn2+ levels are elevated, coinciding with increased MG23 expression. In conclusion, these data suggest that dysregulated Zn2+ homeostasis alters the function of both RyR2 and MG23 and that both ion channels play a key role in diastolic SR Ca2+ leakage.
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Affiliation(s)
- Benedict Reilly-O'Donnell
- From the School of Medicine, University of St. Andrews, St. Andrews, KY16 9TF, Scotland, United Kingdom
| | - Gavin B Robertson
- From the School of Medicine, University of St. Andrews, St. Andrews, KY16 9TF, Scotland, United Kingdom
| | - Angela Karumbi
- From the School of Medicine, University of St. Andrews, St. Andrews, KY16 9TF, Scotland, United Kingdom
| | - Connor McIntyre
- From the School of Medicine, University of St. Andrews, St. Andrews, KY16 9TF, Scotland, United Kingdom
| | - Wojciech Bal
- Department of Biophysics, Institute of Biochemistry and Biophysics, Polish Academy of Science, Warsaw, 02-106 Poland, and
| | - Miyuki Nishi
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Hiroshi Takeshima
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Alan J Stewart
- From the School of Medicine, University of St. Andrews, St. Andrews, KY16 9TF, Scotland, United Kingdom
| | - Samantha J Pitt
- From the School of Medicine, University of St. Andrews, St. Andrews, KY16 9TF, Scotland, United Kingdom,
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43
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Greiser M. Calcium signalling silencing in atrial fibrillation. J Physiol 2017; 595:4009-4017. [PMID: 28332202 DOI: 10.1113/jp273045] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 01/05/2017] [Indexed: 01/19/2023] Open
Abstract
Subcellular calcium signalling silencing is a novel and distinct cellular and molecular adaptive response to rapid cardiac activation. Calcium signalling silencing develops during short-term sustained rapid atrial activation as seen clinically during paroxysmal atrial fibrillation (AF). It is the first 'anti-arrhythmic' adaptive response in the setting of AF and appears to counteract the maladaptive changes that lead to intracellular Ca2+ signalling instability and Ca2+ -based arrhythmogenicity. Calcium signalling silencing results in a failed propagation of the [Ca2+ ]i signal to the myocyte centre both in patients with AF and in a rabbit model. This adaptive mechanism leads to a substantial reduction in the expression levels of calcium release channels (ryanodine receptors, RyR2) in the sarcoplasmic reticulum, and the frequency of Ca2+ sparks and arrhythmogenic Ca2+ waves remains low. Less Ca2+ release per [Ca2+ ]i transient, increased fast Ca2+ buffering strength, shortened action potentials and reduced L-type Ca2+ current contribute to a substantial reduction of intracellular [Na+ ]. These features of Ca2+ signalling silencing are distinct and in contrast to the changes attributed to Ca2+ -based arrhythmogenicity. Some features of Ca2+ signalling silencing prevail in human AF suggesting that the Ca2+ signalling 'phenotype' in AF is a sum of Ca2+ stabilizing (Ca2+ signalling silencing) and Ca2+ destabilizing (arrhythmogenic unstable Ca2+ signalling) factors. Calcium signalling silencing is a part of the mechanisms that contribute to the natural progression of AF and may limit the role of Ca2+ -based arrhythmogenicity after the onset of AF.
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Affiliation(s)
- Maura Greiser
- Center for Biomedical Engineering and Technology and Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
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44
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The effect of PKA-mediated phosphorylation of ryanodine receptor on SR Ca 2+ leak in ventricular myocytes. J Mol Cell Cardiol 2017; 104:9-16. [PMID: 28131630 DOI: 10.1016/j.yjmcc.2017.01.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 11/22/2016] [Accepted: 01/24/2017] [Indexed: 01/08/2023]
Abstract
Functional impact of cardiac ryanodine receptor (type 2 RyR or RyR2) phosphorylation by protein kinase A (PKA) remains highly controversial. In this study, we characterized a functional link between PKA-mediated RyR2 phosphorylation level and sarcoplasmic reticulum (SR) Ca2+ release and leak in permeabilized rabbit ventricular myocytes. Changes in cytosolic [Ca2+] and intra-SR [Ca2+]SR were measured with Fluo-4 and Fluo-5N, respectively. Changes in RyR2 phosphorylation at two PKA sites, serine-2031 and -2809, were measured with phospho-specific antibodies. cAMP (10μM) increased Ca2+ spark frequency approximately two-fold. This effect was associated with an increase in SR Ca2+ load from 0.84 to 1.24mM. PKA inhibitory peptide (PKI; 10μM) abolished the cAMP-dependent increase of SR Ca2+ load and spark frequency. When SERCA was completely blocked by thapsigargin, cAMP did not affect RyR2-mediated Ca2+ leak. The lack of a cAMP effect on RyR2 function can be explained by almost maximal phosphorylation of RyR2 at serine-2809 after sarcolemma permeabilization. This high RyR2 phosphorylation level is likely the consequence of a balance shift between protein kinase and phosphatase activity after permeabilization. When RyR2 phosphorylation at serine-2809 was reduced to its "basal" level (i.e. RyR2 phosphorylation level in intact myocytes) using kinase inhibitor staurosporine, SR Ca2+ leak was significantly reduced. Surprisingly, further dephosphorylation of RyR2 with protein phosphatase 1 (PP1) markedly increased SR Ca2+ leak. At the same time, phosphorylation of RyR2 at serine 2031 did not significantly change under identical experimental conditions. These results suggest that RyR2 phosphorylation by PKA has a complex effect on SR Ca2+ leak in ventricular myocytes. At an intermediate level of RyR2 phosphorylation SR Ca2+ leak is minimal. However, complete dephosphorylation and maximal phosphorylation of RyR2 increases SR Ca2+ leak.
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45
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Alvarado FJ, Chen X, Valdivia HH. Ablation of the cardiac ryanodine receptor phospho-site Ser2808 does not alter the adrenergic response or the progression to heart failure in mice. Elimination of the genetic background as critical variable. J Mol Cell Cardiol 2017; 103:40-47. [PMID: 28065668 DOI: 10.1016/j.yjmcc.2017.01.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 01/04/2017] [Indexed: 10/20/2022]
Abstract
BACKGROUND Phosphorylation of the cardiac ryanodine receptor (RyR2) phospho-site S2808 has been touted by the Marks group as a hallmark of heart failure (HF) and a critical mediator of the physiological fight-or-flight response of the heart. In support of this hypothesis, mice unable to undergo phosphorylation at RyR2-S2808 (S2808A) were significantly protected against HF and displayed a blunted response to adrenergic stimulation. However, the issue remains highly controversial because several groups have been unable to reproduce these findings. An important variable not considered before is the genetic background of the mice used to obtain these divergent results. METHODS AND RESULTS We backcrossed a RyR2-S2808A mouse into a congenic C57Bl/6 strain, the same strain used by the Marks group to conduct their experiments. We then performed several key experiments to confirm or discard the genetic background of the mouse as a relevant variable, including induction of HF by myocardial infarction and tests of integrity of adrenergic response. Congenic C57Bl/6 harboring the S2808A mutation showed similar echocardiographic parameters that indicated identical progression towards HF compared to wild type controls, and had a normal response to adrenergic stimulation in whole animal and cellular experiments. CONCLUSIONS The genetic background of the different mouse models is unlikely to be the source of the divergent results obtained by the Marks group in comparison to several other groups. Cardiac adrenergic response and progression towards HF proceed unaltered in mice harboring the RyR2-S2808A mutation. Preventing RyR2-S2808 phosphorylation does not preclude a normal sympathetic response nor mitigates the pathophysiological consequences of MI.
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Affiliation(s)
- Francisco J Alvarado
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States.
| | - Xi Chen
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States
| | - Héctor H Valdivia
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States; Center for Arrhythmia Research, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, United States.
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Ding Z, Peng J, Liang Y, Yang C, Jiang G, Ren J, Zou Y. Evolution of Vertebrate Ryanodine Receptors Family in Relation to Functional Divergence and Conservation. Int Heart J 2017; 58:969-977. [DOI: 10.1536/ihj.16-558] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Zhiwen Ding
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University
- Institute of Biomedical Sciences, Fudan University
| | - Juan Peng
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University
| | - Yanyan Liang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University
- Department of Cardiology, The First People's Hospital, Shanghai Jiao Tong University School of Medicine
| | - Chunjie Yang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University
| | - Guoliang Jiang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University
| | - Jun Ren
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University
- University of Wyoming College of Health Sciences
| | - Yunzeng Zou
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University
- Institute of Biomedical Sciences, Fudan University
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Terentyev D, Hamilton S. Regulation of sarcoplasmic reticulum Ca 2+ release by serine-threonine phosphatases in the heart. J Mol Cell Cardiol 2016; 101:156-164. [PMID: 27585747 DOI: 10.1016/j.yjmcc.2016.08.020] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 08/26/2016] [Accepted: 08/27/2016] [Indexed: 12/17/2022]
Abstract
The amount and timing of Ca2+ release from the sarcoplasmic reticulum (SR) during cardiac cycle are the main determinants of cardiac contractility. Reversible phosphorylation of the SR Ca2+ release channel, ryanodine receptor type 2 (RyR2) is the central mechanism of regulation of Ca2+ release in cardiomyocytes. Three major serine-threonine phosphatases including PP1, PP2A and PP2B (calcineurin) have been implicated in modulation of RyR2 function. Changes in expression levels of these phosphatases, their activity and targeting to the RyR2 macromolecular complex were demonstrated in many animal models of cardiac disease and humans and are implicated in cardiac arrhythmia and heart failure. Here we review evidence in support of regulation of RyR2-mediated SR Ca2+ release by serine-threonine phosphatases and the role and mechanisms of dysregulation of phosphatases in various disease states.
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Affiliation(s)
- Dmitry Terentyev
- The Warren Alpert Medical School of Brown University, Rhode Island Hospital, Department of Medicine, Cardiovascular Research Center, United States.
| | - Shanna Hamilton
- Cardiff University, School of Medicine, Wales Heart Research Institute, United Kingdom
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Sun X, Zhang X, Bo Q, Meng T, Lei Z, Li J, Hou Y, Yu X, Yu J. Propofol reduced myocardial contraction of vertebrates partly by mediating the cyclic AMP-dependent protein kinase phosphorylation pathway. Toxicology 2016; 365:59-66. [DOI: 10.1016/j.tox.2016.08.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 07/21/2016] [Accepted: 08/01/2016] [Indexed: 11/27/2022]
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49
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Wu Y, Valdivia HH, Wehrens XHT, Anderson ME. A Single Protein Kinase A or Calmodulin Kinase II Site Does Not Control the Cardiac Pacemaker Ca2+ Clock. Circ Arrhythm Electrophysiol 2016; 9:e003180. [PMID: 26857906 DOI: 10.1161/circep.115.003180] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Fight or flight heart rate (HR) increases depend on protein kinase A (PKA)- and calmodulin kinase II (CaMKII)-mediated enhancement of Ca(2+) uptake and release from sarcoplasmic reticulum (SR) in sinoatrial nodal cells (SANC). However, the impact of specific PKA and CaMKII phosphorylation sites on HR is unknown. METHODS AND RESULTS We systematically evaluated validated PKA and CaMKII target sites on phospholamban and the ryanodine receptor using genetically modified mice. We found that knockin alanine replacement of ryanodine receptor PKA (S2808) or CaMKII (S2814) target sites failed to affect HR responses to isoproterenol or spontaneous activity in vivo or in SANC. Similarly, selective mutation of phospholamban amino acids critical for enhancing SR Ca(2+) uptake by PKA (S16) or CaMKII (T17) to alanines did not affect HR in vivo or in SANC. In contrast, CaMKII inhibition by expression of AC3-I has been shown to slow SANC rate responses to isoproterenol and decrease SR Ca(2+) content. Phospholamban deficiency rescued SR Ca(2+) content and SANC rate responses to isoproterenol in mice with AC3-I expression, suggesting that CaMKII affects HR by modulation of SR Ca(2+) content. Consistent with this, mice expressing a superinhibitory phospholamban mutant had low SR Ca(2+) content and slow HR in vivo and in SANC. CONCLUSIONS SR Ca(2+) depletion reduces HR and SR Ca(2+) repletion restores physiological SANC rate responses, despite CaMKII inhibition. PKA and CaMKII do not affect HR by a unique target site governing SR Ca(2+) uptake or release. HR acceleration may require an SR Ca(2+) content threshold.
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Affiliation(s)
- Yuejin Wu
- From the Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD (Y.W., M.E.A.); Center for Arrhythmia Research, Cardiovascular Division, Department of Internal Medicine, University of Michigan, Ann Arbor (H.H.V.); and Cardiovascular Research Institute, Departments of Molecular Physiology and Biophysics, Medicine, Pediatrics, Baylor College of Medicine, Houston, TX (X.H.T.W.).
| | - Héctor H Valdivia
- From the Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD (Y.W., M.E.A.); Center for Arrhythmia Research, Cardiovascular Division, Department of Internal Medicine, University of Michigan, Ann Arbor (H.H.V.); and Cardiovascular Research Institute, Departments of Molecular Physiology and Biophysics, Medicine, Pediatrics, Baylor College of Medicine, Houston, TX (X.H.T.W.)
| | - Xander H T Wehrens
- From the Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD (Y.W., M.E.A.); Center for Arrhythmia Research, Cardiovascular Division, Department of Internal Medicine, University of Michigan, Ann Arbor (H.H.V.); and Cardiovascular Research Institute, Departments of Molecular Physiology and Biophysics, Medicine, Pediatrics, Baylor College of Medicine, Houston, TX (X.H.T.W.)
| | - Mark E Anderson
- From the Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD (Y.W., M.E.A.); Center for Arrhythmia Research, Cardiovascular Division, Department of Internal Medicine, University of Michigan, Ann Arbor (H.H.V.); and Cardiovascular Research Institute, Departments of Molecular Physiology and Biophysics, Medicine, Pediatrics, Baylor College of Medicine, Houston, TX (X.H.T.W.).
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Bcl-2 and FKBP12 bind to IP3 and ryanodine receptors at overlapping sites: the complexity of protein-protein interactions for channel regulation. Biochem Soc Trans 2016; 43:396-404. [PMID: 26009182 DOI: 10.1042/bst20140298] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The 12- and 12.6-kDa FK506-binding proteins, FKBP12 (12-kDa FK506-binding protein) and FKBP12.6 (12.6-kDa FK506-binding protein), have been implicated in the binding to and the regulation of ryanodine receptors (RyRs) and inositol 1,4,5-trisphosphate receptors (IP3Rs), both tetrameric intracellular Ca2+-release channels. Whereas the amino acid sequences responsible for FKBP12 binding to RyRs are conserved in IP3Rs, FKBP12 binding to IP3Rs has been questioned and could not be observed in various experimental models. Nevertheless, conservation of these residues in the different IP3R isoforms and during evolution suggested that they could harbour an important regulatory site critical for IP3R-channel function. Recently, it has become clear that in IP3Rs, this site was targeted by B-cell lymphoma 2 (Bcl-2) via its Bcl-2 homology (BH)4 domain, thereby dampening IP3R-mediated Ca2+ flux and preventing pro-apoptotic Ca2+ signalling. Furthermore, vice versa, the presence of the corresponding site in RyRs implied that Bcl-2 proteins could associate with and regulate RyR channels. Recently, the existence of endogenous RyR-Bcl-2 complexes has been identified in primary hippocampal neurons. Like for IP3Rs, binding of Bcl-2 to RyRs also involved its BH4 domain and suppressed RyR-mediated Ca2+ release. We therefore propose that the originally identified FKBP12-binding site in IP3Rs is a region critical for controlling IP3R-mediated Ca2+ flux by recruiting Bcl-2 rather than FKBP12. Although we hypothesize that anti-apoptotic Bcl-2 proteins, but not FKBP12, are the main physiological inhibitors of IP3Rs, we cannot exclude that Bcl-2 could help engaging FKBP12 (or other FKBP isoforms) to the IP3R, potentially via calcineurin.
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