1
|
Xing Y, Cui T, Sun F. A novel RyR2 mutation associated with co-morbid catecholaminergic polymorphic ventricular tachycardia (CPVT) and benign epilepsy with centrotemporal spikes (BECTS). J Electrocardiol 2024; 84:75-80. [PMID: 38574633 DOI: 10.1016/j.jelectrocard.2024.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 03/19/2024] [Accepted: 03/19/2024] [Indexed: 04/06/2024]
Abstract
In this case report, we describe a 14-year-old patient with a novel RyR2 gene mutation (c.6577G > T/p.Val2193Leu), identified through a comprehensive review of medical history, examination findings, and follow-up data. The pathogenic potential of this mutation, which results in the loss of some interatomic forces and compromises the closure of the RyR2 protein pore leading to calcium leakage, was analyzed using the I-TASSER Suite to predict the structural changes in the protein. This mutation manifested clinically as co-morbid catecholaminergic polymorphic ventricular tachycardia (CPVT) and benign epilepsy with centrotemporal spikes (BECTS), a combination not previously documented in the same patient. While seizures were successfully managed with levetiracetam, the patient's exercise-induced syncope episodes could not be controlled with metoprolol, highlighting the complexity and challenge in managing CPVT associated with this novel RyR2 variation.
Collapse
Affiliation(s)
- Yinxue Xing
- Department of Neurology, Affiliated Xing Tai People Hospital of Hebei Medical University, Xingtai, Hebei, China.
| | - Tao Cui
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China; China National Clinical Research Center for Neurological Disease, NCRC-ND, Beijing, China
| | - Fan Sun
- Department of Neurology, Affiliated Hospital of Chengde Medical University, Chengde, Hebei, China
| |
Collapse
|
2
|
Xu J, Liao C, Yin CC, Li G, Zhu Y, Sun F. In situ structural insights into the excitation-contraction coupling mechanism of skeletal muscle. SCIENCE ADVANCES 2024; 10:eadl1126. [PMID: 38507485 PMCID: PMC10954225 DOI: 10.1126/sciadv.adl1126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 02/12/2024] [Indexed: 03/22/2024]
Abstract
Excitation-contraction coupling (ECC) is a fundamental mechanism in control of skeletal muscle contraction and occurs at triad junctions, where dihydropyridine receptors (DHPRs) on transverse tubules sense excitation signals and then cause calcium release from the sarcoplasmic reticulum via coupling to type 1 ryanodine receptors (RyR1s), inducing the subsequent contraction of muscle filaments. However, the molecular mechanism remains unclear due to the lack of structural details. Here, we explored the architecture of triad junction by cryo-electron tomography, solved the in situ structure of RyR1 in complex with FKBP12 and calmodulin with the resolution of 16.7 Angstrom, and found the intact RyR1-DHPR supercomplex. RyR1s arrange into two rows on the terminal cisternae membrane by forming right-hand corner-to-corner contacts, and tetrads of DHPRs bind to RyR1s in an alternating manner, forming another two rows on the transverse tubule membrane. This unique arrangement is important for synergistic calcium release and provides direct evidence of physical coupling in ECC.
Collapse
Affiliation(s)
- Jiashu Xu
- Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chenyi Liao
- Laboratory of Molecular Modeling and Design, State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Chang-Cheng Yin
- Department of Biophysics, The Health Science Center, Peking University, Beijing 100191, China
- Electron Microscopy Analysis Laboratory, The Health Science Center, Peking University, Beijing 100191, China
- Center for Protein Science, Peking University, Beijing 100871, China
| | - Guohui Li
- Laboratory of Molecular Modeling and Design, State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Yun Zhu
- Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Fei Sun
- Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Center for Biological Imaging, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou, Guangdong, 510005, China
| |
Collapse
|
3
|
Hua X, Yao J, Liu X, Liu Q, Deng Y, Li S, Valdivia CR, Wang F, Pozzolini M, Shou Z, Valdivia HH, Xiao L. Comparison of the structure-function of five newly members of the calcin family. Int J Biol Macromol 2024; 260:129424. [PMID: 38219929 DOI: 10.1016/j.ijbiomac.2024.129424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 01/03/2024] [Accepted: 01/09/2024] [Indexed: 01/16/2024]
Abstract
Calcins are a group of scorpion toxin peptides specifically binding to ryanodine receptors (RyRs) with high affinity, and have the ability to activate and stabilize RyR in a long-lasting subconductance state. Five newly calcins synthesized compounds exhibit typical structural characteristics of a specific family through chemical synthesis and virtual analysis. As the calcins from the same species, Petersiicalcin1 and Petersiicalcin2, Jendekicalcin2 and Jendekicalcin3, have only one residue difference. Both Petersiicalcin1 and Petersiicalcin2 exhibited different affinities in stimulating [3H]ryanodine binding, but the residue mutation resulted in a 2.7 folds difference. Other calcins also exhibited a stimulatory effect on [3H]ryanodine binding to RyR1, however, their affinities were significantly lower than that of Petersiiicalcin1 and Petersiiicalcin2. The channel domain of RyR1 was found to be capable of binding with the basic residues of these calcins, which also exhibited interactions with the S6 helices on RyR1. Dynamic simulations were conducted for Petersiicalcin1 and Petersiicalcin2, which demonstrated their ability to form a highly stable conformation and resulting in an asymmetric tetramer structure of RyR1. The discovery of five newly calcins further enriches the diversity of the natural calcin family, which provides more native peptides for the structure-function analysis between calcin and RyRs.
Collapse
Affiliation(s)
- Xiaoyu Hua
- Department of Occupational and Environmental Health, Faculty of Naval Medicine, Naval Medical University (Second Military Medical University), Shanghai 200433, China
| | - Jinchi Yao
- Department of Occupational and Environmental Health, Faculty of Naval Medicine, Naval Medical University (Second Military Medical University), Shanghai 200433, China; School of Life Sciences, Liaoning Normal University, Dalian 116081, China
| | - Xinyan Liu
- Department of Traditional Chinese Medicine Surgery, the First Affiliated Hospital of the Navy Medical University, Shanghai, 200433, China
| | - Qing Liu
- College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Shanxi, Taigu 030801, China
| | - Yuchen Deng
- Department of Dermatology, Second Affiliated Hospital of Naval Medical University, Shanghai 200003, China
| | - Songhua Li
- Department of Cardiology, Changhai Hospital, Naval Medical University, Shanghai, China
| | - Carmen R Valdivia
- Department of Medicine and Cardiovascular Research Center, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA.
| | - Fei Wang
- Department of Occupational and Environmental Health, Faculty of Naval Medicine, Naval Medical University (Second Military Medical University), Shanghai 200433, China
| | - Marina Pozzolini
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genova, Via Pastore 3, 16132 Genova, Italy.
| | - Zhaoyong Shou
- Faculty of Health Service, Nacal Medical University (Second Military Medical University), Shanghai 200433, China.
| | - Héctor H Valdivia
- Department of Medicine and Cardiovascular Research Center, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA.
| | - Liang Xiao
- Department of Occupational and Environmental Health, Faculty of Naval Medicine, Naval Medical University (Second Military Medical University), Shanghai 200433, China.
| |
Collapse
|
4
|
Molecular, Subcellular, and Arrhythmogenic Mechanisms in Genetic RyR2 Disease. Biomolecules 2022; 12:biom12081030. [PMID: 35892340 PMCID: PMC9394283 DOI: 10.3390/biom12081030] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 07/22/2022] [Accepted: 07/24/2022] [Indexed: 11/17/2022] Open
Abstract
The ryanodine receptor (RyR2) has a critical role in controlling Ca2+ release from the sarcoplasmic reticulum (SR) throughout the cardiac cycle. RyR2 protein has multiple functional domains with specific roles, and four of these RyR2 protomers are required to form the quaternary structure that comprises the functional channel. Numerous mutations in the gene encoding RyR2 protein have been identified and many are linked to a wide spectrum of arrhythmic heart disease. Gain of function mutations (GoF) result in a hyperactive channel that causes excessive spontaneous SR Ca2+ release. This is the predominant cause of the inherited syndrome catecholaminergic polymorphic ventricular tachycardia (CPVT). Recently, rare hypoactive loss of function (LoF) mutations have been identified that produce atypical effects on cardiac Ca2+ handling that has been termed calcium release deficiency syndrome (CRDS). Aberrant Ca2+ release resulting from both GoF and LoF mutations can result in arrhythmias through the Na+/Ca2+ exchange mechanism. This mini-review discusses recent findings regarding the role of RyR2 domains and endogenous regulators that influence RyR2 gating normally and with GoF/LoF mutations. The arrhythmogenic consequences of GoF/LoF mutations will then be discussed at the macromolecular and cellular level.
Collapse
|
5
|
A Comparative Perspective on Functionally-Related, Intracellular Calcium Channels: The Insect Ryanodine and Inositol 1,4,5-Trisphosphate Receptors. Biomolecules 2021; 11:biom11071031. [PMID: 34356655 PMCID: PMC8301844 DOI: 10.3390/biom11071031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 07/08/2021] [Accepted: 07/10/2021] [Indexed: 02/03/2023] Open
Abstract
Calcium (Ca2+) homeostasis is vital for insect development and metabolism, and the endoplasmic reticulum (ER) is a major intracellular reservoir for Ca2+. The inositol 1,4,5- triphosphate receptor (IP3R) and ryanodine receptor (RyR) are large homotetrameric channels associated with the ER and serve as two major actors in ER-derived Ca2+ supply. Most of the knowledge on these receptors derives from mammalian systems that possess three genes for each receptor. These studies have inspired work on synonymous receptors in insects, which encode a single IP3R and RyR. In the current review, we focus on a fundamental, common question: “why do insect cells possess two Ca2+ channel receptors in the ER?”. Through a comparative approach, this review covers the discovery of RyRs and IP3Rs, examines their structures/functions, the pathways that they interact with, and their potential as target sites in pest control. Although insects RyRs and IP3Rs share structural similarities, they are phylogenetically distinct, have their own structural organization, regulatory mechanisms, and expression patterns, which explains their functional distinction. Nevertheless, both have great potential as target sites in pest control, with RyRs currently being targeted by commercial insecticide, the diamides.
Collapse
|
6
|
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.
Collapse
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.
| |
Collapse
|
7
|
Altered Organelle Calcium Transport in Ovarian Physiology and Cancer. Cancers (Basel) 2020; 12:cancers12082232. [PMID: 32785177 PMCID: PMC7464720 DOI: 10.3390/cancers12082232] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 07/31/2020] [Accepted: 08/06/2020] [Indexed: 12/14/2022] Open
Abstract
Calcium levels have a huge impact on the physiology of the female reproductive system, in particular, of the ovaries. Cytosolic calcium levels are influenced by regulatory proteins (i.e., ion channels and pumps) localized in the plasmalemma and/or in the endomembranes of membrane-bound organelles. Imbalances between plasma membrane and organelle-based mechanisms for calcium regulation in different ovarian cell subtypes are contributing to ovarian pathologies, including ovarian cancer. In this review, we focused our attention on altered calcium transport and its role as a contributor to tumor progression in ovarian cancer. The most important proteins described as contributing to ovarian cancer progression are inositol trisphosphate receptors, ryanodine receptors, transient receptor potential channels, calcium ATPases, hormone receptors, G-protein-coupled receptors, and/or mitochondrial calcium uniporters. The involvement of mitochondrial and/or endoplasmic reticulum calcium imbalance in the development of resistance to chemotherapeutic drugs in ovarian cancer is also discussed, since Ca2+ channels and/or pumps are nowadays regarded as potential therapeutic targets and are even correlated with prognosis.
Collapse
|
8
|
Seidel M, de Meritens CR, Johnson L, Parthimos D, Bannister M, Thomas NL, Ozekhome-Mike E, Lai FA, Zissimopoulos S. Identification of an amino-terminus determinant critical for ryanodine receptor/Ca2+ release channel function. Cardiovasc Res 2020; 117:780-791. [PMID: 32077934 PMCID: PMC7898959 DOI: 10.1093/cvr/cvaa043] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 12/05/2019] [Accepted: 02/17/2020] [Indexed: 01/12/2023] Open
Abstract
AIMS The cardiac ryanodine receptor (RyR2), which mediates intracellular Ca2+ release to trigger cardiomyocyte contraction, participates in development of acquired and inherited arrhythmogenic cardiac disease. This study was undertaken to characterize the network of inter- and intra-subunit interactions regulating the activity of the RyR2 homotetramer. METHODS AND RESULTS We use mutational investigations combined with biochemical assays to identify the peptide sequence bridging the β8 with β9 strand as the primary determinant mediating RyR2 N-terminus self-association. The negatively charged side chains of two aspartate residues (D179 and D180) within the β8-β9 loop are crucial for the N-terminal inter-subunit interaction. We also show that the RyR2 N-terminus domain interacts with the C-terminal channel pore region in a Ca2+-independent manner. The β8-β9 loop is required for efficient RyR2 subunit oligomerization but it is dispensable for N-terminus interaction with C-terminus. Deletion of the β8-β9 sequence produces unstable tetrameric channels with subdued intracellular Ca2+ mobilization implicating a role for this domain in channel opening. The arrhythmia-linked R176Q mutation within the β8-β9 loop decreases N-terminus tetramerization but does not affect RyR2 subunit tetramerization or the N-terminus interaction with C-terminus. RyR2R176Q is a characteristic hypersensitive channel displaying enhanced intracellular Ca2+ mobilization suggesting an additional role for the β8-β9 domain in channel closing. CONCLUSION These results suggest that efficient N-terminus inter-subunit communication mediated by the β8-β9 loop may constitute a primary regulatory mechanism for both RyR2 channel activation and suppression.
Collapse
Affiliation(s)
- Monika Seidel
- Department of Cardiology, School of Medicine, Wales Heart Research Institute, Cardiff University, Heath Park, Cardiff CF14 4XN, UK.,Swansea University Medical School, Institute of Life Science, Swansea SA2 8PP, UK
| | - Camille Rabesahala de Meritens
- Department of Cardiology, School of Medicine, Wales Heart Research Institute, Cardiff University, Heath Park, Cardiff CF14 4XN, UK.,Swansea University Medical School, Institute of Life Science, Swansea SA2 8PP, UK
| | - Louisa Johnson
- Department of Cardiology, School of Medicine, Wales Heart Research Institute, Cardiff University, Heath Park, Cardiff CF14 4XN, UK.,Swansea University Medical School, Institute of Life Science, Swansea SA2 8PP, UK
| | - Dimitris Parthimos
- Department of Cardiology, School of Medicine, Wales Heart Research Institute, Cardiff University, Heath Park, Cardiff CF14 4XN, UK.,Division of Cancer & Genetics, School of Medicine, Cardiff University, Cardiff CF14 4XN, UK
| | - Mark Bannister
- Department of Cardiology, School of Medicine, Wales Heart Research Institute, Cardiff University, Heath Park, Cardiff CF14 4XN, UK.,Swansea University Medical School, Institute of Life Science, Swansea SA2 8PP, UK
| | - Nia Lowri Thomas
- Department of Cardiology, School of Medicine, Wales Heart Research Institute, Cardiff University, Heath Park, Cardiff CF14 4XN, UK.,School of Pharmacy & Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, UK
| | - Esizaze Ozekhome-Mike
- Department of Cardiology, School of Medicine, Wales Heart Research Institute, Cardiff University, Heath Park, Cardiff CF14 4XN, UK.,Swansea University Medical School, Institute of Life Science, Swansea SA2 8PP, UK
| | - Francis Anthony Lai
- College of Medicine, QU Health, and Biomedical Research Centre, Qatar University, Doha, Qatar
| | - Spyros Zissimopoulos
- Department of Cardiology, School of Medicine, Wales Heart Research Institute, Cardiff University, Heath Park, Cardiff CF14 4XN, UK.,Swansea University Medical School, Institute of Life Science, Swansea SA2 8PP, UK
| |
Collapse
|
9
|
Zhou X, Park KH, Yamazaki D, Lin PH, Nishi M, Ma Z, Qiu L, Murayama T, Zou X, Takeshima H, Zhou J, Ma J. TRIC-A Channel Maintains Store Calcium Handling by Interacting With Type 2 Ryanodine Receptor in Cardiac Muscle. Circ Res 2019; 126:417-435. [PMID: 31805819 DOI: 10.1161/circresaha.119.316241] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
RATIONALE Trimeric intracellular cation (TRIC)-A and B are distributed to endoplasmic reticulum/sarcoplasmic reticulum intracellular Ca2+ stores. The crystal structure of TRIC has been determined, confirming the homotrimeric structure of a potassium channel. While the pore architectures of TRIC-A and TRIC-B are conserved, the carboxyl-terminal tail (CTT) domains of TRIC-A and TRIC-B are different from each other. Aside from its recognized role as a counterion channel that participates in excitation-contraction coupling of striated muscles, the physiological function of TRIC-A in heart physiology and disease has remained largely unexplored. OBJECTIVE In cardiomyocytes, spontaneous Ca2+ waves, triggered by store overload-induced Ca2+ release mediated by the RyR2 (type 2 ryanodine receptor), develop extrasystolic contractions often associated with arrhythmic events. Here, we test the hypothesis that TRIC-A is a physiological component of RyR2-mediated Ca2+ release machinery that directly modulates store overload-induced Ca2+ release activity via CTT. METHODS AND RESULTS We show that cardiomyocytes derived from the TRIC-A-/- (TRIC-A knockout) mice display dysregulated Ca2+ movement across sarcoplasmic reticulum. Biochemical studies demonstrate a direct interaction between CTT-A and RyR2. Modeling and docking studies reveal potential sites on RyR2 that show differential interactions with CTT-A and CTT-B. In HEK293 (human embryonic kidney) cells with stable expression of RyR2, transient expression of TRIC-A, but not TRIC-B, leads to apparent suppression of spontaneous Ca2+ oscillations. Ca2+ measurements using the cytosolic indicator Fura-2 and the endoplasmic reticulum luminal store indicator D1ER suggest that TRIC-A enhances Ca2+ leak across the endoplasmic reticulum by directly targeting RyR2 to modulate store overload-induced Ca2+ release. Moreover, synthetic CTT-A peptide facilitates RyR2 activity in lipid bilayer reconstitution system, enhances Ca2+ sparks in permeabilized TRIC-A-/- cardiomyocytes, and induces intracellular Ca2+ release after microinjection into isolated cardiomyocytes, whereas such effects were not observed with the CTT-B peptide. In response to isoproterenol stimulation, the TRIC-A-/- mice display irregular ECG and develop more fibrosis than the WT (wild type) littermates. CONCLUSIONS In addition to the ion-conducting function, TRIC-A functions as an accessory protein of RyR2 to modulate sarcoplasmic reticulum Ca2+ handling in cardiac muscle.
Collapse
Affiliation(s)
- Xinyu Zhou
- From the Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University, Columbus (X. Zhou, K.H.P., P.-h.L., J.M.)
| | - Ki Ho Park
- From the Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University, Columbus (X. Zhou, K.H.P., P.-h.L., J.M.)
| | - Daiju Yamazaki
- Department of Biological Chemistry, Kyoto University Graduate School of Pharmaceutical Sciences, Japan (D.Y., M.N., H.T.)
| | - Pei-Hui Lin
- From the Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University, Columbus (X. Zhou, K.H.P., P.-h.L., J.M.)
| | - Miyuki Nishi
- Department of Biological Chemistry, Kyoto University Graduate School of Pharmaceutical Sciences, Japan (D.Y., M.N., H.T.)
| | - Zhiwei Ma
- Department of Physics and Astronomy, Dalton Cardiovascular Research Center (Z.M., L.Q., X. Zou), University of Missouri, Columbia.,Department of Biochemistry (Z.M., L.Q., X. Zou), University of Missouri, Columbia
| | - Liming Qiu
- Department of Physics and Astronomy, Dalton Cardiovascular Research Center (Z.M., L.Q., X. Zou), University of Missouri, Columbia.,Department of Biochemistry (Z.M., L.Q., X. Zou), University of Missouri, Columbia
| | - Takashi Murayama
- Department of Pharmacology, Juntendo University School of Medicine, Tokyo, Japan (T.M.)
| | - Xiaoqin Zou
- Department of Physics and Astronomy, Dalton Cardiovascular Research Center (Z.M., L.Q., X. Zou), University of Missouri, Columbia.,Department of Biochemistry (Z.M., L.Q., X. Zou), University of Missouri, Columbia
| | - Hiroshi Takeshima
- Department of Biological Chemistry, Kyoto University Graduate School of Pharmaceutical Sciences, Japan (D.Y., M.N., H.T.)
| | - Jingsong Zhou
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington (J.Z.)
| | - Jianjie Ma
- From the Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University, Columbus (X. Zhou, K.H.P., P.-h.L., J.M.)
| |
Collapse
|
10
|
De Mandal S, Shakeel M, Prabhakaran VS, Karthi S, Xu X, Jin F. Alternative splicing and insect ryanodine receptor. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2019; 102:e21590. [PMID: 31218747 DOI: 10.1002/arch.21590] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 04/20/2019] [Accepted: 05/22/2019] [Indexed: 06/09/2023]
Abstract
Phylogenetic tree of the ryanodine receptor (RyR) family based on maximum likelihood estimation.
Collapse
Affiliation(s)
- Surajit De Mandal
- Laboratory of Bio-Pesticide Creation and Application of Guangdong Province, College of Agriculture, Department of Entomology, South China Agricultural University, Guangzhou, People's Republic of China
| | - Muhammad Shakeel
- Laboratory of Bio-Pesticide Creation and Application of Guangdong Province, College of Agriculture, Department of Entomology, South China Agricultural University, Guangzhou, People's Republic of China
| | | | - Sengodan Karthi
- Department of Environmental Sciences, Manonmaniam Sundaranar University, Tirunelveli, Tamilnadu, India
| | - Xiaoxia Xu
- Laboratory of Bio-Pesticide Creation and Application of Guangdong Province, College of Agriculture, Department of Entomology, South China Agricultural University, Guangzhou, People's Republic of China
| | - Fengliang Jin
- Laboratory of Bio-Pesticide Creation and Application of Guangdong Province, College of Agriculture, Department of Entomology, South China Agricultural University, Guangzhou, People's Republic of China
| |
Collapse
|
11
|
Xu L, Chirasani VR, Carter JS, Pasek DA, Dokholyan NV, Yamaguchi N, Meissner G. Ca 2+-mediated activation of the skeletal-muscle ryanodine receptor ion channel. J Biol Chem 2018; 293:19501-19509. [PMID: 30341173 DOI: 10.1074/jbc.ra118.004453] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 10/14/2018] [Indexed: 02/05/2023] Open
Abstract
Cryo-electron micrograph studies recently have identified a Ca2+-binding site in the 2,200-kDa ryanodine receptor ion channel (RyR1) in skeletal muscle. To clarify the role of this site in regulating RyR1 activity, here we applied mutational, electrophysiological, and computational methods. Three amino acid residues that interact directly with Ca2+ were replaced, and these RyR1 variants were expressed in HEK293 cells. Single-site RyR1-E3893Q, -E3893V, -E3967Q, -E3967V, and -T5001A variants and double-site RyR1-E3893Q/E3967Q and -E3893V/E3967V variants displayed cellular Ca2+ release in response to caffeine, which indicated that they retained functionality as caffeine-sensitive, Ca2+-conducting channels in the HEK293 cell system. Using [3H]ryanodine binding and single-channel measurements of membrane isolates, we found that single- and double-site RyR1-E3893 and -E3967 variants are not activated by Ca2+ We also noted that RyR1-E3893Q/E3967Q and -E3893V/E3967V variants maintain caffeine- and ATP-induced activation and that RyR1-E3893Q/E3967Q is inhibited by Mg2+ and elevated Ca2+ RyR1-T5001A exhibited decreased Ca2+ sensitivity compared with WT-RyR1 in single-channel measurements. Computational methods suggested that electrostatic interactions between Ca2+ and negatively charged glutamate residues have a critical role in transducing the functional effects of Ca2+ on RyR1. We conclude that the removal of negative charges in the recently identified RyR1 Ca2+-binding site impairs RyR1 activation by physiological Ca2+ concentrations and results in loss of binding to Ca2+ or reduced Ca2+ affinity of the binding site.
Collapse
Affiliation(s)
- Le Xu
- From the Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599-7260
| | - Venkat R Chirasani
- From the Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599-7260.,the Departments of Pharmacology and Biochemistry and Molecular Biology, Penn State College of Medicine, Hershey, Pennsylvania 17033-0850
| | - Jordan S Carter
- the Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, South Carolina 29425, and.,the Cardiac Signaling Center, Clemson University, Charleston, South Carolina 29425
| | - Daniel A Pasek
- From the Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599-7260
| | - Nikolay V Dokholyan
- From the Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599-7260.,the Departments of Pharmacology and Biochemistry and Molecular Biology, Penn State College of Medicine, Hershey, Pennsylvania 17033-0850
| | - Naohiro Yamaguchi
- the Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, South Carolina 29425, and.,the Cardiac Signaling Center, Clemson University, Charleston, South Carolina 29425
| | - Gerhard Meissner
- From the Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599-7260,
| |
Collapse
|
12
|
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: 154] [Impact Index Per Article: 22.0] [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.
Collapse
Affiliation(s)
- Gerhard Meissner
- Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina, Chapel Hill, NC
| |
Collapse
|
13
|
Faltinova A, Tomaskova N, Antalik M, Sevcik J, Zahradnikova A. The N-Terminal Region of the Ryanodine Receptor Affects Channel Activation. Front Physiol 2017; 8:443. [PMID: 28713282 PMCID: PMC5492033 DOI: 10.3389/fphys.2017.00443] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 06/12/2017] [Indexed: 11/29/2022] Open
Abstract
Mutations in the cardiac ryanodine receptor (RyR2), the ion channel responsible for release of calcium ions from intracellular stores into cytoplasm, are the cause of several inherited cardiac arrhythmias. At the molecular level, disease symptoms can be mimicked by domain peptides from mutation-prone regions of RyR2 that bind to RyR2 and activate it. Here we show that the domain peptide DPcpvtN2, corresponding to the central helix of the N-terminal region of RyR2, activates the RyR2 channel. Structural modeling of interaction between DPcpvtN2 and the N-terminal region of RyR2 in the closed and open conformation provided three plausible structures of the complex. Only one of them could explain the dependence of RyR2 activity on concentration of DPcpvtN2. The structure of the complex was at odds with the previously proposed “domain switch” mechanism of competition between domain peptides and ryanodine receptor domains. Likewise, in structural models of the N-terminal region, the conformational changes induced by DPcpvtN2 binding were different from those induced by mutation of central helix amino acids. The activating effect of DPcpvtN2 binding and of mutations in the central helix could be explained by their similar effect on the transition energy between the closed and open conformation of RyR2.
Collapse
Affiliation(s)
- Andrea Faltinova
- Department of Muscle Cell Research, Institute of Molecular Physiology and Genetics of the Centre of Biosciences, Slovak Academy of SciencesBratislava, Slovakia.,Department of Biochemistry and Structural Biology, Institute of Molecular Biology, Slovak Academy of SciencesBratislava, Slovakia
| | - Nataša Tomaskova
- Faculty of Science, Institute of Chemical Sciences, Pavol Jozef Šafárik UniversityKošice, Slovakia
| | - Marián Antalik
- Faculty of Science, Institute of Chemical Sciences, Pavol Jozef Šafárik UniversityKošice, Slovakia
| | - Jozef Sevcik
- Department of Biochemistry and Structural Biology, Institute of Molecular Biology, Slovak Academy of SciencesBratislava, Slovakia
| | - Alexandra Zahradnikova
- Department of Muscle Cell Research, Institute of Molecular Physiology and Genetics of the Centre of Biosciences, Slovak Academy of SciencesBratislava, Slovakia.,Department of Biochemistry and Structural Biology, Institute of Molecular Biology, Slovak Academy of SciencesBratislava, Slovakia
| |
Collapse
|
14
|
Mowrey DD, Xu L, Mei Y, Pasek DA, Meissner G, Dokholyan NV. Ion-pulling simulations provide insights into the mechanisms of channel opening of the skeletal muscle ryanodine receptor. J Biol Chem 2017; 292:12947-12958. [PMID: 28584051 DOI: 10.1074/jbc.m116.760199] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/20/2017] [Indexed: 12/13/2022] Open
Abstract
The type 1 ryanodine receptor (RyR1) mediates Ca2+ release from the sarcoplasmic reticulum to initiate skeletal muscle contraction and is associated with muscle diseases, malignant hyperthermia, and central core disease. To better understand RyR1 channel function, we investigated the molecular mechanisms of channel gating and ion permeation. An adequate model of channel gating requires accurate, high-resolution models of both open and closed states of the channel. To this end, we generated an open-channel RyR1 model using molecular simulations to pull Ca2+ through the pore constriction site of a closed-channel RyR1 structure determined at 3.8-Å resolution. Importantly, we find that our open-channel model is consistent with the RyR1 and cardiac RyR (RyR2) open-channel structures reported while this paper was in preparation. Both our model and the published structures show similar rotation of the upper portion of the pore-lining S6 helix away from the 4-fold channel axis and twisting of Ile-4937 at the channel constriction site out of the channel pore. These motions result in a minimum open-channel pore radius of ∼3 Å formed by Gln-4933, rather than Ile-4937 in the closed-channel structure. We also present functional support for our model by mutations around the closed- and open-channel constriction sites (Gln-4933 and Ile-4937). Our results indicate that use of ion-pulling simulations produces a RyR1 open-channel model, which can provide insights into the mechanisms of channel opening complementing those from the structural data.
Collapse
Affiliation(s)
- David D Mowrey
- Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599-7260
| | - Le Xu
- Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599-7260
| | - Yingwu Mei
- Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599-7260
| | - Daniel A Pasek
- Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599-7260
| | - Gerhard Meissner
- Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599-7260.
| | - Nikolay V Dokholyan
- Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599-7260.
| |
Collapse
|
15
|
Gaburjakova M, Gaburjakova J. Insight towards the identification of cytosolic Ca 2+ -binding sites in ryanodine receptors from skeletal and cardiac muscle. Acta Physiol (Oxf) 2017; 219:757-767. [PMID: 27543850 DOI: 10.1111/apha.12772] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 07/13/2016] [Accepted: 08/12/2016] [Indexed: 11/30/2022]
Abstract
Ca2+ plays a critical role in several processes involved in skeletal and cardiac muscle contraction. One key step in cardiac excitation-contraction (E-C) coupling is the activation of the cardiac ryanodine receptor (RYR2) by cytosolic Ca2+ elevations. Although this process is not critical for skeletal E-C coupling, the activation and inhibition of the skeletal ryanodine receptor (RYR1) seem to be important for overall muscle function. The RYR1 and RYR2 channels fall within the large category of Ca2+ -binding proteins that harbour highly selective Ca2+ -binding sites to receive and translate the various Ca2+ signals into specific functional responses. However, little is known about the precise localization of these sites within the cytosolic assembly of both RYR isoforms, although several experimental lines of evidence have highlighted their EF-hand nature. EF-hand proteins share a common helix-loop-helix structural motif with highly conserved residues involved in Ca2+ coordination. The first step in predicting EF-hand positive regions is to compare the primary protein structure with the EF-hand motif by employing available bioinformatics tools. Although this simple method narrows down search regions, it does not provide solid evidence regarding which regions bind Ca2+ in both RYR isoforms. In this review, we seek to highlight the key findings and experimental approaches that should strengthen our future efforts to identify the cytosolic Ca2+ -binding sites responsible for activation and inhibition in the RYR1 channel, as much less work has been conducted on the RYR2 channel.
Collapse
Affiliation(s)
- M. Gaburjakova
- Institute of Molecular Physiology and Genetics; Slovak Academy of Sciences; Bratislava Slovak Republic
| | - J. Gaburjakova
- Institute of Molecular Physiology and Genetics; Slovak Academy of Sciences; Bratislava Slovak Republic
| |
Collapse
|
16
|
Structure-Function Relationship of the Voltage-Gated Calcium Channel Cav1.1 Complex. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 981:23-39. [DOI: 10.1007/978-3-319-55858-5_2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
|
17
|
Intensity matters: Ryanodine receptor regulation during exercise. Proc Natl Acad Sci U S A 2015; 112:15271-2. [PMID: 26631747 DOI: 10.1073/pnas.1521051112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
|
18
|
Song Y, Kang S, Park S. Structural characterization of calmodulin like domain of ryanodine receptor type 1. JOURNAL OF THE KOREAN MAGNETIC RESONANCE SOCIETY 2015. [DOI: 10.6564/jkmrs.2015.19.2.074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
19
|
Molecular Characterization, mRNA Expression and Alternative Splicing of Ryanodine Receptor Gene in the Brown Citrus Aphid, Toxoptera citricida (Kirkaldy). Int J Mol Sci 2015; 16:15220-34. [PMID: 26154764 PMCID: PMC4519896 DOI: 10.3390/ijms160715220] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 06/11/2015] [Accepted: 06/29/2015] [Indexed: 12/24/2022] Open
Abstract
Ryanodine receptors (RyRs) play a critical role in regulating the release of intracellular calcium, which enables them to be effectively targeted by the two novel classes of insecticides, phthalic acid diamides and anthranilic diamides. However, less information is available about this target site in insects, although the sequence and structure information of target molecules are essential for designing new control agents of high selectivity and efficiency, as well as low non-target toxicity. Here, we provided sufficient information about the coding sequence and molecular structures of RyR in T. citricida (TciRyR), an economically important pest. The full-length TciRyR cDNA was characterized with an open reading frame of 15,306 nucleotides, encoding 5101 amino acid residues. TciRyR was predicted to embrace all the hallmarks of ryanodine receptor, typically as the conserved C-terminal domain with consensus calcium-biding EF-hands (calcium-binding motif) and six transmembrane domains, as well as a large N-terminal domain. qPCR analysis revealed that the highest mRNA expression levels of TciRyR were observed in the adults, especially in the heads. Alternative splicing in TciRyR was evidenced by an alternatively spliced exon, resulting from intron retention, which was different from the case of RyR in Myzus persicae characterized with no alternative splicing events. Diagnostic PCR analysis indicated that the splicing of this exon was not only regulated in a body-specific manner but also in a stage-dependent manner. Taken together, these results provide useful information for new insecticide design and further insights into the molecular basis of insecticide action.
Collapse
|
20
|
Van B, Nishi M, Komazaki S, Ichimura A, Kakizawa S, Nakanaga K, Aoki J, Park KH, Ma J, Ueyama T, Ogata T, Maruyama N, Takeshima H. Mitsugumin 56 (hedgehog acyltransferase-like) is a sarcoplasmic reticulum-resident protein essential for postnatal muscle maturation. FEBS Lett 2015; 589:1095-104. [DOI: 10.1016/j.febslet.2015.03.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 03/24/2015] [Accepted: 03/26/2015] [Indexed: 02/02/2023]
|
21
|
Structure of the rabbit ryanodine receptor RyR1 at near-atomic resolution. Nature 2014; 517:50-55. [PMID: 25517095 PMCID: PMC4338550 DOI: 10.1038/nature14063] [Citation(s) in RCA: 327] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 11/12/2014] [Indexed: 12/12/2022]
Abstract
The ryanodine receptors (RyRs) are high-conductance intracellular Ca2+ channels that play a pivotal role in the excitation-contraction coupling of skeletal and cardiac muscles. RyRs are the largest known ion channels, with a homotetrameric organization and approximately 5000 residues in each protomer. Here we report the structure of the rabbit RyR1 in complex with its modulator FKBP12 at an overall resolution of 3.8 Å, determined by single-particle electron cryo-microscopy. Three previously uncharacterized domains, named Central, Handle, and Helical domains, display the armadillo repeat fold. These domains, together with the amino-terminal domain, constitute a network of superhelical scaffold for binding and propagation of conformational changes. The channel domain exhibits the voltage-gated ion channel superfamily fold with distinct features. A negative charge-enriched hairpin loop connecting S5 and the pore helix is positioned above the entrance to the selectivity filter vestibule. The four elongated S6 segments form a right-handed helical bundle that closes the pore at the cytoplasmic border of the membrane. Allosteric regulation of the pore by the cytoplasmic domains is mediated through extensive interactions between the Central domains and the channel domain. These structural features explain high ion conductance by RyRs and the long-range allosteric regulation of channel activities.
Collapse
|
22
|
Seidel M, Thomas NL, Williams AJ, Lai FA, Zissimopoulos S. Dantrolene rescues aberrant N-terminus intersubunit interactions in mutant pro-arrhythmic cardiac ryanodine receptors. Cardiovasc Res 2014; 105:118-28. [PMID: 25411383 DOI: 10.1093/cvr/cvu240] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS The ryanodine receptor (RyR2) is an intracellular Ca(2+) release channel essential for cardiac excitation-contraction coupling. Abnormal RyR2 channel function results in the generation of arrhythmias and sudden cardiac death. The present study was undertaken to investigate the mechanistic basis of RyR2 dysfunction in inherited arrhythmogenic cardiac disease. METHODS AND RESULTS We present several lines of complementary evidence, indicating that the arrhythmia-associated L433P mutation disrupts RyR2 N-terminus self-association. A combination of yeast two-hybrid, co-immunoprecipitation, and chemical cross-linking assays collectively demonstrate that a RyR2 N-terminal fragment carrying the L433P mutation displays substantially reduced self-interaction compared with wild type. Moreover, sucrose density gradient centrifugation reveals that the L433P mutation impairs tetramerization of the full-length channel. [(3)H]Ryanodine-binding assays demonstrate that disrupted N-terminal intersubunit interactions within RyR2(L433P) confer an altered sensitivity to Ca(2+) activation. Calcium imaging of RyR2(L433P)-expressing cells reveals substantially prolonged Ca(2+) transients and reduced Ca(2+) store content indicating defective channel closure. Importantly, dantrolene treatment reverses the L433P mutation-induced impairment and restores channel function. CONCLUSION The N-terminus domain constitutes an important structural determinant for the functional oligomerization of RyR2. Our findings are consistent with defective N-terminus self-association as a molecular mechanism underlying RyR2 channel deregulation in inherited arrhythmogenic cardiac disease. Significantly, the therapeutic action of dantrolene may occur via the restoration of normal RyR2 N-terminal intersubunit interactions.
Collapse
Affiliation(s)
- Monika Seidel
- Wales Heart Research Institute, Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Cardiff CF14 4XN, UK
| | - N Lowri Thomas
- Wales Heart Research Institute, Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Cardiff CF14 4XN, UK
| | - Alan J Williams
- Wales Heart Research Institute, Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Cardiff CF14 4XN, UK
| | - F Anthony Lai
- Wales Heart Research Institute, Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Cardiff CF14 4XN, UK
| | - Spyros Zissimopoulos
- Wales Heart Research Institute, Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Cardiff CF14 4XN, UK
| |
Collapse
|
23
|
Borko Ľ, Bauerová-Hlinková V, Hostinová E, Gašperík J, Beck K, Lai FA, Zahradníková A, Ševčík J. Structural insights into the human RyR2 N-terminal region involved in cardiac arrhythmias. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2014; 70:2897-912. [PMID: 25372681 PMCID: PMC4220973 DOI: 10.1107/s1399004714020343] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 09/10/2014] [Indexed: 01/11/2023]
Abstract
Human ryanodine receptor 2 (hRyR2) mediates calcium release from the sarcoplasmic reticulum, enabling cardiomyocyte contraction. The N-terminal region of hRyR2 (amino acids 1-606) is the target of >30 arrhythmogenic mutations and contains a binding site for phosphoprotein phosphatase 1. Here, the solution and crystal structures determined under near-physiological conditions, as well as a homology model of the hRyR2 N-terminal region, are presented. The N-terminus is held together by a unique network of interactions among its three domains, A, B and C, in which the central helix (amino acids 410-437) plays a prominent stabilizing role. Importantly, the anion-binding site reported for the mouse RyR2 N-terminal region is notably absent from the human RyR2. The structure concurs with the differential stability of arrhythmogenic mutations in the central helix (R420W, I419F and I419F/R420W) which are owing to disparities in the propensity of mutated residues to form energetically favourable or unfavourable contacts. In solution, the N-terminus adopts a globular shape with a prominent tail that is likely to involve residues 545-606, which are unresolved in the crystal structure. Docking the N-terminal domains into cryo-electron microscopy maps of the closed and open RyR1 conformations reveals C(α) atom movements of up to 8 Å upon channel gating, and predicts the location of the leucine-isoleucine zipper segment and the interaction site for spinophilin and phosphoprotein phosphatase 1 on the RyR surface.
Collapse
Affiliation(s)
- Ľubomír Borko
- Department of Biochemistry and Structural Biology, Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia
| | - Vladena Bauerová-Hlinková
- Department of Biochemistry and Structural Biology, Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia
| | - Eva Hostinová
- Department of Biochemistry and Structural Biology, Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia
| | - Juraj Gašperík
- Department of Biochemistry and Structural Biology, Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia
| | - Konrad Beck
- Cardiff University School of Dentistry, Heath Park, Cardiff CF14 4XY, Wales
| | - F. Anthony Lai
- Department of Cardiology, Wales Heart Research Institute, Cardiff University School of Medicine, Cardiff CF14 4XN, Wales
| | - Alexandra Zahradníková
- Department of Biochemistry and Structural Biology, Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia
- Department of Muscle Cell Research, Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Vlárska 5, 833 34 Bratislava, Slovakia
| | - Jozef Ševčík
- Department of Biochemistry and Structural Biology, Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia
| |
Collapse
|
24
|
Ye Y, Jian K, Jaggar JH, Bukiya AN, Dopico AM. Type 2 ryanodine receptors are highly sensitive to alcohol. FEBS Lett 2014; 588:1659-65. [PMID: 24631538 PMCID: PMC4193545 DOI: 10.1016/j.febslet.2014.03.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 02/27/2014] [Accepted: 03/01/2014] [Indexed: 11/16/2022]
Abstract
Exposure to ethanol levels reached in circulation during alcohol intoxication (>10mM) constricts cerebral arteries in rats and humans. Remarkably, targets and mechanisms underlying this action remain largely unidentified. Artery diameter is regulated by myocyte Ca(2+) sparks, a vasodilatory signal contributed to by type 2 ryanodine receptors (RyR2). Using laser confocal microscopy in rat cerebral arteries and bilayer electrophysiology we unveil that ethanol inhibits both Ca(2+) spark and RyR2 activity with IC50<20 mM, placing RyR2 among the ion channels that are most sensitive to ethanol. Alcohol directly targets RyR2 and its lipid microenvironment, leading to stabilization of RyR2 closed states.
Collapse
Affiliation(s)
- Yanping Ye
- Department of Pharmacology, The University of Tennessee Health Science Center, Memphis, TN 38163, United States
| | - Kuihuan Jian
- Department of Pharmacology, The University of Tennessee Health Science Center, Memphis, TN 38163, United States
| | - Jonathan H Jaggar
- Department of Physiology, The University of Tennessee Health Science Center, Memphis, TN 38163, United States
| | - Anna N Bukiya
- Department of Pharmacology, The University of Tennessee Health Science Center, Memphis, TN 38163, United States
| | - Alex M Dopico
- Department of Pharmacology, The University of Tennessee Health Science Center, Memphis, TN 38163, United States.
| |
Collapse
|
25
|
Yuan GR, Shi WZ, Yang WJ, Jiang XZ, Dou W, Wang JJ. Molecular characteristics, mRNA expression, and alternative splicing of a ryanodine receptor gene in the oriental fruit fly, Bactrocera dorsalis (Hendel). PLoS One 2014; 9:e95199. [PMID: 24740254 PMCID: PMC3989282 DOI: 10.1371/journal.pone.0095199] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 03/24/2014] [Indexed: 01/13/2023] Open
Abstract
Ryanodine receptors (RyRs) are a distinct class of ligand-gated channels controlling the release of calcium from intracellular stores. The emergence of diamide insecticides, which selectively target insect RyRs, has promoted the study of insect RyRs. In the present study, the full-length RyR cDNA (BdRyR) was cloned and characterized from the oriental fruit fly, Bactrocera dorsalis (Hendel), a serious pest of fruits and vegetables throughout East Asia and the Pacific Rim. The cDNA of BdRyR contains a 15,420-bp open reading frame encoding 5,140 amino acids with a predicted molecular weight of 582.4 kDa and an isoelectric point of 5.38. BdRyR shows a high level of amino acid sequence identity (78 to 97%) to other insect RyR isoforms. All common structural features of the RyRs are present in the BdRyR, including a well-conserved C-terminal domain containing consensus calcium-binding EF-hands and six transmembrane domains, and a large N-terminal domain. Quantitative real-time PCR analyses revealed that BdRyR was expressed at the lowest and highest levels in egg and adult, respectively, and that the BdRyR expression levels in the third instar larva, pupa and adult were 166.99-, 157.56- and 808.56-fold higher, respectively, than that in the egg. Among different adult body parts, the highest expression level was observed in the thorax compared with the head and abdomen. In addition, four alternative splice sites were identified in the BdRyR gene, with the first, ASI, being located in the central part of the predicted second spore lysis A/RyR domain. Diagnostic PCR analyses revealed that alternative splice variants were generated not only in a tissue-specific manner but also in a developmentally regulated manner. These results lay the foundation for further understanding the structural and functional properties of BdRyR, and the molecular mechanisms for target site resistance in B. dorsalis.
Collapse
Affiliation(s)
- Guo-Rui Yuan
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
| | - Wen-Zhi Shi
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
| | - Wen-Jia Yang
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
| | - Xuan-Zhao Jiang
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
| | - Wei Dou
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
| | - Jin-Jun Wang
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
| |
Collapse
|
26
|
Abstract
AbstractThe effect of a domain peptide DPCPVTc from the central region of the RYR2 on ryanodine receptors from rat heart has been examined in planar lipid bilayers. At a zero holding potential and at 8 mmol L−1 luminal Ca2+ concentration, DPCPVTc induced concentrationdependent activation of the ryanodine receptor that led up to 20-fold increase of PO at saturating DPCPVTc concentrations. DPCPVTc prolonged RyR2 openings and increased RyR2 opening frequency. At all peptide concentrations the channels displayed large variability in open probability, open time and frequency of openings. With increasing peptide concentration, the fraction of high open probability records increased together with their open time. The closed times of neither low- nor high-open probability records depended on peptide concentration. The concentration dependence of all gating parameters had EC50 of 20 μmol L−1 and a Hill slope of 2. Comparison of the effects of DPCPVTc with the effects of ATP and cytosolic Ca2+ suggests that activation does not involve luminal feed-through and is not caused by modulation of the cytosolic activation A-site. The data suggest that although “domain unzipping” by DPCPVTc occurs in both modes of RyR activity, it affects RyR gating only when the channel resides in the H-mode of activity.
Collapse
|
27
|
Liu Y, Shahzad MF, Zhang L, Li F, Lin K. Amplifying long transcripts of ryanodine receptors of five agricultural pests by transcriptome analysis and gap filling. Genome 2013; 56:651-8. [PMID: 24299104 DOI: 10.1139/gen-2013-0127] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ryanodine receptor (RyR) is an intracellular calcium release channel that plays a key role in excitation contraction coupling. Insect RyR is the target of diamide insecticides. Better understanding of insect RyR is necessary for studying the molecular mode of action and potential resistance mechanism of diamide insecticides. However, molecular manipulation of the full RyR gene is difficult because of its length (approximately 15 kb). At present, RyR genes have been reported only in a limited number of insects. Here, we developed an efficient strategy to amplify full-length transcripts of insect RyR genes. First, we searched the transcriptomes of five insects, Bemisia tabaci, Cnaphalocrocis medinalis, Chilo suppressalis, Laodelphgax striatellus, and Plutella xylostella, yielding 85 RyR contigs in total. Second, the relative positions of these contigs in RyR transcripts were determined by aligning them with 12 well-annotated RyRs. Third, we designed primers to fill gaps between contigs and used rapid amplification of cDNA ends (RACE) to amplify both 5'- and 3'-ends. Last, we assembled all fragments into long transcripts. As a result, full-length transcripts of three insects, C. suppressalis, L. striatellus, and P. xylostella, were obtained. The RyR transcript of B. tabaci was near full length, containing an intact ORF. Northern blot analysis indicated that RyR genes were expressed in all five insects. Sequence analyses showed that the amplified insect segments contained typical RyRs characteristics, such as EF-hand, motif GVRAGGGIGD, and six transmembrane domains. Seven lepidopteran-specific amino acid residues were found to be located in the C-terminal region of RyR proteins, which might be associated with the specificity of RyRs to diamide insecticides.
Collapse
Affiliation(s)
- Yonglei Liu
- a Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | | | | | | | | |
Collapse
|
28
|
Cui L, Yang D, Yan X, Rui C, Wang Z, Yuan H. Molecular cloning, characterization and expression profiling of a ryanodine receptor gene in Asian corn borer, Ostrinia furnacalis (Guenée). PLoS One 2013; 8:e75825. [PMID: 24098400 PMCID: PMC3787966 DOI: 10.1371/journal.pone.0075825] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Accepted: 08/19/2013] [Indexed: 11/19/2022] Open
Abstract
Ryanodine receptor (RyR) Ca(2+) release channel is the target of diamide insecticides, which show selective insecticidal activity against lepidopterous insects. To study the molecular mechanisms underlying the species-specific action of diamide insecticides, we have cloned and characterized the entire cDNA sequence of RyR from Ostrinia furnacalis (named as OfRyR). The OfRyR mRNA has an Open Reading Frame of 15324 bp nucleotides and encodes a 5108 amino acid polypeptide that displays 79-97% identity with other insects RyR proteins and shows the greatest identity with Cnaphalocrocis medinalis RyR (97%). Quantitative real-time PCR showed that the OfRyR was expressed at the lowest level in egg and the highest level in adult. The relative expression level of OfRyR in first, third and fifth-instar larva were 1.28, 1.19 and 1.99 times of that in egg. Moreover, two alternative splicing sites were identified in the OfRyR gene. One pair of mutually exclusive exons (a/b) were present in the central part of the predicted SPRY domain, and an optional exon (c) was located between the third and fourth RyR domains. Diagnostic PCR demonstrated that exons a and b existed in all developmental stages of OfRyR cDNA, but exon c was not detected in the egg cDNA. And the usage frequencies of these exons showed a significant difference between different developmental stages. These results provided the crucial basis for the functional expression of OfRyR and for the discovery of compound with potentially selective insect activtity.
Collapse
Affiliation(s)
- Li Cui
- Key Laboratory of Integrated Pest Management in Crops, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Daibin Yang
- Key Laboratory of Integrated Pest Management in Crops, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiaojing Yan
- Key Laboratory of Integrated Pest Management in Crops, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Changhui Rui
- Key Laboratory of Integrated Pest Management in Crops, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Zhenying Wang
- Key Laboratory of Integrated Pest Management in Crops, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Huizhu Yuan
- Key Laboratory of Integrated Pest Management in Crops, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- * E-mail:
| |
Collapse
|
29
|
Wu S, Wang F, Huang J, Fang Q, Shen Z, Ye G. Molecular and cellular analyses of a ryanodine receptor from hemocytes of Pieris rapae. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2013; 41:1-10. [PMID: 23603125 DOI: 10.1016/j.dci.2013.04.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 04/01/2013] [Accepted: 04/05/2013] [Indexed: 06/02/2023]
Abstract
Ryanodine receptors (RyRs) are located in the sarcoplasmic/endoplasmic reticulum membrane and are a distinct class of ligand-gated calcium channels controlling the release of calcium from intracellular stores. Intracellular calcium level has a definite role in innate and adaptive immune signaling. However, very few information are accessible about calcium transients of invertebrate immunocytes, especially of insect hemocytes, the effector cells of insect immunity. In this study, we show that the RyR-stimulating agent flubendiamide inhibit hemocyte spreading and phagocytosis in the cabbage white butterfly, Pieris rapae. Furthermore, we cloned a cDNA encoding a ryanodine receptor (PrRyR) from the hemocytes of P. rapae. It encodes 5107 amino acids with a predicted molecular weight of 578.2 kDa. PrRyR shares a common feature with known RyRs: a well-conserved COOH-terminal domain with two consensus calcium-binding EF-hands and six transmembrane domains, and a large hydrophilic NH2-terminal domain. In the larval stage, PrRyR was highly expressed in epidermis tissue and also expressed in hemocytes at a moderate level. In the adult stage, PrRyR was expressed at high levels in thoraces and legs, while low levels in abdomens and antennae. Quantitative real-time PCR analysis showed that its expression did not display any significant change in response to bacterial challenge. Western blot analysis and immunohistochemistry assay displayed that PrRyR was detected and presented on hemocytes. We also showed that flubendiamide, a RyR-activating insecticide, induced Ca(2+) release and thereby confirmed functional expression of the PrRyR in the hemocytes of P. rapae.
Collapse
Affiliation(s)
- Shunfan Wu
- State Key Laboratory of Rice Biology, Key Laboratory of Agricultural Entomology of Ministry of Agriculture, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China
| | | | | | | | | | | |
Collapse
|
30
|
Zissimopoulos S, Viero C, Seidel M, Cumbes B, White J, Cheung I, Stewart R, Jeyakumar LH, Fleischer S, Mukherjee S, Thomas NL, Williams AJ, Lai FA. N-terminus oligomerization regulates the function of cardiac ryanodine receptors. J Cell Sci 2013; 126:5042-51. [PMID: 23943880 DOI: 10.1242/jcs.133538] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The ryanodine receptor (RyR) is an ion channel composed of four identical subunits mediating calcium efflux from the endo/sarcoplasmic reticulum of excitable and non-excitable cells. We present several lines of evidence indicating that the RyR2 N-terminus is capable of self-association. A combination of yeast two-hybrid screens, co-immunoprecipitation analysis, chemical crosslinking and gel filtration assays collectively demonstrate that a RyR2 N-terminal fragment possesses the intrinsic ability to oligomerize, enabling apparent tetramer formation. Interestingly, N-terminus tetramerization mediated by endogenous disulfide bond formation occurs in native RyR2, but notably not in RyR1. Disruption of N-terminal inter-subunit interactions within RyR2 results in dysregulation of channel activation at diastolic Ca(2+) concentrations from ryanodine binding and single channel measurements. Our findings suggest that the N-terminus interactions mediating tetramer assembly are involved in RyR channel closure, identifying a crucial role for this structural association in the dynamic regulation of intracellular Ca(2+) release.
Collapse
Affiliation(s)
- Spyros Zissimopoulos
- Wales Heart Research Institute, Cardiff University School of Medicine, Cardiff CF14 4XN, UK
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Takamori M. Structure of the neuromuscular junction: function and cooperative mechanisms in the synapse. Ann N Y Acad Sci 2013; 1274:14-23. [PMID: 23252893 DOI: 10.1111/j.1749-6632.2012.06784.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
As an overview of the structure of the neuromuscular junction, three items are described focusing on cooperative mechanisms involving the synapse and leading to muscle contraction: (1) presynaptic acetylcholine release regulated by vesicle cycling (exocytosis and endocytosis); the fast-mode of endocytosis requires a large influx of external Ca(2+) and is promoted by the activation of G protein-coupled receptors and receptor tyrosine kinases; (2) postsynaptic acetylcholine receptor clustering mediated by the muscle-specific, Dok7-stimulated tyrosine kinase (MuSK) through two signaling mechanisms: one via agrin-Lrp4-MuSK (Ig1/2 domains) and the second via Wnt-MuSK (Frizzled-like cysteine-rich domain)-adaptor Dishevelled; Wnts/MuSK and Lrp4 direct a retrograde signal to presynaptic differentiation; (3) muscle contractile machinery regulated by Ca(2+) -release and Ca(2+) -influx channels, including the depolarization-activated ryanodine receptor-1 and the receptor- and/or store-operated transient receptor potential canonical. The first mechanism is dysfunctional in Lambert-Eaton myasthenic syndrome, the second in anti-acetylcholine receptor-negative myasthenia gravis (MG), and the third in thymoma-associated MG.
Collapse
|
32
|
Mapping domains and mutations on the skeletal muscle ryanodine receptor channel. Trends Mol Med 2012; 18:644-57. [DOI: 10.1016/j.molmed.2012.09.006] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 08/14/2012] [Accepted: 09/19/2012] [Indexed: 11/20/2022]
|
33
|
Contribution of anti-ryanodine receptor antibody to impairment of excitation–contraction coupling in myasthenia gravis. Clin Neurophysiol 2012; 123:1242-7. [DOI: 10.1016/j.clinph.2011.10.038] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Revised: 09/01/2011] [Accepted: 10/02/2011] [Indexed: 11/21/2022]
|
34
|
Wang J, Li Y, Han Z, Zhu Y, Xie Z, Wang J, Liu Y, Li X. Molecular characterization of a ryanodine receptor gene in the rice leaffolder, Cnaphalocrocis medinalis (Guenée). PLoS One 2012; 7:e36623. [PMID: 22567170 PMCID: PMC3342285 DOI: 10.1371/journal.pone.0036623] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 04/03/2012] [Indexed: 11/25/2022] Open
Abstract
Ryanodine receptors (RyRs) are the targets of two novel classes of synthetic insecticidal chemicals, phthalic acid diamides and anthranilic diamides. Isolation of full-length RyR cDNAs is a critical step towards the structural and functional characterization of insect RyRs and an understanding of the molecular mechanisms underlying the species selective toxicity of diamide insecticides. However, there has been little research on the insect RyR genes due to the high molecular weight of the RyR proteins. In this study, we isolated a full-length RyR cDNA (named as CmRyR) from Cnaphalocrocis medinalis, an important rice pest throughout Southeast Asia. The composite CmRyR gene contains an ORF of 15264 bp encoding a protein of 5087 amino acid residues, which shares 79% overall identity with its Drosophila melanogaster homologue. All hallmarks of the RyR proteins are conserved in the CmRyR protein, suggesting that CmRyR is a structural and functional analogue of known RyRs. A multiple sequence alignment illustrates that the insect RyRs share high levels of amino acid sequence identity at the the COOH-terminal region. However, the amino acid residues analogous to the CmRyR residues N4922, N4924, N4935, L4950, L4981, N5013 and T5064 are unique to lepidopteran RyRs compared with non-lepidopteran insect RyRs. This finding suggests that these residues may be involved in the differences in channel properties between lepidopteran and non-lepidopteran insect RyRs and in the species selective toxicity of diamide insecticides. Furthermore, two alternative splicing sites were identified in the CmRyR gene, one of which was located in the central part of the predicted second SPRY domain. Diagnostic PCR showed that the inclusion frequencies of two mutually exclusive exons (a/b) and one optional exon (c) differed between developmental stages or adult anatomical regions. Our results imply that alternative splicing may be a major means of generating functional diversity in C. medinalis RyR channel.
Collapse
Affiliation(s)
- Jianjun Wang
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, China.
| | | | | | | | | | | | | | | |
Collapse
|
35
|
Imai T, Tsuda E, Hozuki T, Yamauchi R, Saitoh M, Hisahara S, Yoshikawa H, Motomura M, Kawamata J, Shimohama S. Early effect of tacrolimus in improving excitation-contraction coupling in myasthenia gravis. Clin Neurophysiol 2012; 123:1886-90. [PMID: 22386321 DOI: 10.1016/j.clinph.2012.01.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 12/27/2011] [Accepted: 01/27/2012] [Indexed: 12/31/2022]
Abstract
OBJECTIVES Tacrolimus (FK506) is a macrolide T-cell immunomodulator used to treat myasthenia gravis (MG). Besides immunosuppression, tacrolimus has been reported to have the potential to increase muscle strength by enhancing ryanodine receptor (RyR) function. However, few attempts have been made to demonstrate the early effect of tacrolimus as an RyR enhancer in clinical investigation. METHODS In 20 MG patients, masseteric compound muscle action potential (CMAP) and mandibular movement-related potentials (MRPs) were recorded simultaneously after stimulating the trigeminal motor nerve with a needle electrode. The excitation-contraction (E-C) coupling time (ECCT) was calculated by the latency difference between CMAP and MRP. Bite force was measured using a pressure-sensitive sheet. Serial assessments of % decrement in masseteric repetitive nerve stimulation (RNS), ECCT and bite force were performed before and within 4 weeks of tacrolimus (3 mg day(-1)) treatment. The median (mean, range) interval of assessment was 2 (2.4, 1-4) weeks. We also measured serum antibodies against RyR, acetylcholine receptor and muscle-specific receptor tyrosine kinase. RESULTS Bite force increased after tacrolimus treatment accompanying clinical improvement assessed by Myasthenia Gravis Foundation of America classification, but the bite force difference did not reach statistical significance. Wilcoxon matched-pairs signed-ranks test detected a significant ECCT shortening in 12 patients assessed after 1-2 weeks of tacrolimus treatment as well as in eight patients assessed after 3-4 weeks. In contrast, masseteric CMAP and % decrement showed no significant changes after short-term tacrolimus treatment. CONCLUSIONS Tacrolimus induces ECCT shortening accompanying clinical improvement despite no improvement in % decrement within 2 weeks. SIGNIFICANCE This early effect of tacrolimus may imply a pharmacological enhancement of RyR function to improve E-C coupling in MG.
Collapse
Affiliation(s)
- Tomihiro Imai
- Department of Neurology, Sapporo Medical University School of Medicine, Sapporo, Japan.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Szlufcik K, Missiaen L, Parys JB, Callewaert G, De Smedt H. Uncoupled IP3 receptor can function as a Ca2+-leak channel: cell biological and pathological consequences. Biol Cell 2012; 98:1-14. [PMID: 16354157 DOI: 10.1042/bc20050031] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Ca(2+) release via intracellular release channels, IP(3)Rs (inositol 1,4,5-trisphosphate receptors) and RyRs (ryanodine receptors), is perhaps the most ubiquitous and versatile cellular signalling mechanism, and is involved in a vast number of cellular processes. In addition to this classical release pathway there is limited, but yet persistent, information about less well-defined Ca(2+)-leak pathways that may play an important role in the control of the Ca(2+) load of the endo(sarco)plasmic reticulum. The mechanisms responsible for this 'basal' leak are not known, but recent data suggest that both IP(3)Rs and RyRs may also operate as Ca(2+)-leak channels, particularly in pathological conditions. Proteolytic cleavage or biochemical modification (such as hyperphosphorylation or nitrosylation), for example, occurring during conditions of cell stress or apoptosis, can functionally uncouple the cytoplasmic control domains from the channel domain of the receptor. Highly significant information has been obtained from studies of malfunctioning channels in various disorders; for example, RyRs in cardiac malfunction or genetic muscle diseases and IP(3)Rs in neurodegenerative diseases. In this review we aim to summarize the existing information about functionally uncoupled IP(3)R and RyR channels, and to discuss the concept that those channels can participate in Ca(2+)-leak pathways.
Collapse
|
37
|
Jiang D, Jones PP, Davis DR, Gow R, Green MS, Birnie DH, Chen SRW, Gollob MH. Characterization of a novel mutation in the cardiac ryanodine receptor that results in catecholaminergic polymorphic ventricular tachycardia. Channels (Austin) 2010; 4:302-10. [PMID: 20676041 DOI: 10.4161/chan.4.4.12666] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an arrhythmogenic disease that manifests as syncope or sudden death during high adrenergic tone in the absence of structural heart defects. It is primarily caused by mutations in the cardiac ryanodine receptor (RyR2). The mechanism by which these mutations cause arrhythmia remains controversial, with discrepant findings related to the role of the RyR2 binding protein FKBP12.6. The purpose of this study was to characterize a novel RyR2 mutation identified in a kindred with clinically diagnosed CPVT. Single-strand conformational polymorphism analysis and direct DNA sequencing were used to screen the RyR2 gene for mutations. Site-directed mutagenesis was employed to introduce the mutation into the mouse RyR2 cDNA. The impact of the mutation on the interaction between RyR2 and a 12.6 kDa FK506 binding protein (FKBP12.6) was determined by immunoprecipitation and immunoblotting and its effect on RyR2 function was characterized by single cell Ca(2+) imaging and [(3)H]ryanodine binding. A novel CPVT mutation, E189D, was identified. The E189D mutation does not alter the affinity of the channel for FKBP12.6, but it increases the propensity for store-overload-induced Ca(2+) release (SOICR). Furthermore, the E189D mutation enhances the basal channel activity of RyR2 and its sensitivity to activation by caffeine. The E189D RyR2 mutation is causative for CPVT and functionally increases the propensity for SOICR without altering the affinity for FKBP12.6. These observations strengthen the notion that enhanced SOICR, but not altered FKBP12.6 binding, is a common mechanism by which RyR2 mutations cause arrhythmias.
Collapse
Affiliation(s)
- Dawei Jiang
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Ryanodine receptor studies using genetically engineered mice. FEBS Lett 2010; 584:1956-65. [PMID: 20214899 DOI: 10.1016/j.febslet.2010.03.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Revised: 02/24/2010] [Accepted: 03/03/2010] [Indexed: 11/20/2022]
Abstract
Ryanodine receptors (RyR) regulate intracellular Ca(2+) release in many cell types and have been implicated in a number of inherited human diseases. Over the past 15 years genetically engineered mouse models have been developed to elucidate the role that RyRs play in physiology and pathophysiology. To date these models have implicated RyRs in fundamental biological processes including excitation-contraction coupling and long term plasticity as well as diseases including malignant hyperthermia, cardiac arrhythmias, heart failure, and seizures. In this review we summarize the RyR mouse models and how they have enhanced our understanding of the RyR channels and their roles in cellular physiology and disease.
Collapse
|
39
|
Intracellular Ca2+ storage in health and disease: a dynamic equilibrium. Cell Calcium 2010; 47:297-314. [PMID: 20189643 DOI: 10.1016/j.ceca.2010.02.001] [Citation(s) in RCA: 147] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2009] [Revised: 01/31/2010] [Accepted: 02/01/2010] [Indexed: 12/17/2022]
Abstract
Homeostatic control of the endoplasmic reticulum (ER) both as the site for protein handling (synthesis, folding, trafficking, disaggregation and degradation) and as a Ca2+ store is of crucial importance for correct functioning of the cell. Disturbance of the homeostatic control mechanisms leads to a vast array of severe pathologies. The Ca2+ content of the ER is a dynamic equilibrium between active uptake via Ca2+ pumps and Ca2+ release by a number of highly regulated Ca2+-release channels. Regulation of the Ca2+-release channels is very complex and several mechanisms are still poorly understood or controversial. There is increasing evidence that a number of unrelated proteins, either by themselves or in association with other Ca2+ channels, can provide additional Ca2+-leak pathways. The ER is a dynamic organelle and changes in its size and components have been described, either as a result of (de)differentiation processes affecting the secretory capacity of cells, or as a result of adaptation mechanisms to diverse stress conditions such as the unfolded protein response and autophagy. In this review we want to give an overview of the current knowledge of the (short-term) regulatory mechanisms that affect Ca2+-release and Ca2+-leak pathways and of the (long-term) adaptations in ER size and capacity. Understanding of the consequences of these mechanisms for cellular Ca2+ signaling could provide a huge therapeutic potential.
Collapse
|
40
|
Matos A, Sambuughin N, Rumjanek F, Amoedo N, Cunha L, Zapata-Sudo G, Sudo R. Multigenerational Brazilian family with malignant hyperthermia and a novel mutation in the RYR1 gene. Braz J Med Biol Res 2009. [DOI: 10.1590/s0100-879x2009007500011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
| | - N. Sambuughin
- Uniformed Services University of the Health Sciences, USA
| | | | | | | | | | - R.T. Sudo
- Universidade Federal do Rio de Janeiro
| |
Collapse
|
41
|
Kato K, Kiyonaka S, Sawaguchi Y, Tohnishi M, Masaki T, Yasokawa N, Mizuno Y, Mori E, Inoue K, Hamachi I, Takeshima H, Mori Y. Molecular characterization of flubendiamide sensitivity in the lepidopterous ryanodine receptor Ca(2+) release channel. Biochemistry 2009; 48:10342-52. [PMID: 19807072 DOI: 10.1021/bi900866s] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Flubendiamide is a benzenedicarboxamide derivative that shows selective insecticidal activity against lepidopterous insects. The specific modulatory effects of flubendiamide on ryanodine binding in insect muscle microsomal membranes suggest that the ryanodine receptor (RyR) Ca(2+) release channel is a primary target of flubendiamide. However, the molecular mechanisms underlying the species-specific action of flubendiamide are unclear. We have cloned cDNA encoding a novel RyR from the lepidopterous silkworm RyR (sRyR) and tested the sensitivity to flubendiamide of the recombinant sRyR in HEK293 cells. Confocal localization studies and Ca(2+) imaging techniques revealed that sRyRs form Ca(2+) release channels in the endoplasmic reticulum. Importantly, flubendiamide induced release of Ca(2+) through the sRyR, but not through the rabbit RyR isoforms. Photoaffinity labeling of sRyR deletion mutants using a photoreactive derivative revealed that flubendiamide is mainly incorporated into the transmembrane domain (amino acids 4111-5084) of the sRyR. The rabbit cardiac muscle isoform RyR2 (rRyR2) and the RyR mutant carrying a replacement of the transmembrane domain (residues 4084-5084) with its counterpart sequence from rRyR2 (residues 3936-4968) were not labeled by the photoreactive compound. This replacement in the sRyR significantly impaired the responses to flubendiamide but only marginally reduced the sensitivity to caffeine, a general RyR activator. Furthermore, deletion of the N-terminal sequence (residues 183-290) abolished the responses of the sRyR to flubendiamide but not the sensitivity to caffeine. Our results suggest that the transmembrane domain plays an important role in the formation of an action site for flubendiamide, while the N-terminus is a structural requirement for flubendiamide-induced activation of the sRyR.
Collapse
Affiliation(s)
- Kenta Kato
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Blayney LM, Lai FA. Ryanodine receptor-mediated arrhythmias and sudden cardiac death. Pharmacol Ther 2009; 123:151-77. [PMID: 19345240 PMCID: PMC2704947 DOI: 10.1016/j.pharmthera.2009.03.006] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Accepted: 03/03/2009] [Indexed: 12/25/2022]
Abstract
The cardiac ryanodine receptor-Ca2+ release channel (RyR2) is an essential sarcoplasmic reticulum (SR) transmembrane protein that plays a central role in excitation–contraction coupling (ECC) in cardiomyocytes. Aberrant spontaneous, diastolic Ca2+ leak from the SR due to dysfunctional RyR2 contributes to the formation of delayed after-depolarisations, which are thought to underlie the fatal arrhythmia that occurs in both heart failure (HF) and in catecholaminergic polymorphic ventricular tachycardia (CPVT). CPVT is an inherited disorder associated with mutations in either the RyR2 or a SR luminal protein, calsequestrin. RyR2 shows normal function at rest in CPVT but the RyR2 dysfunction is unmasked by physical exercise or emotional stress, suggesting abnormal RyR2 activation as an underlying mechanism. Several potential mechanisms have been advanced to explain the dysfunctional RyR2 observed in HF and CPVT, including enhanced RyR2 phosphorylation status, altered RyR2 regulation at luminal/cytoplasmic sites and perturbed RyR2 intra/inter-molecular interactions. This review considers RyR2 dysfunction in the context of the structural and functional modulation of the channel, and potential therapeutic strategies to stabilise RyR2 function in cardiac pathology.
Collapse
Affiliation(s)
- Lynda M Blayney
- Wales Heart Research Institute, Cardiff University School of Medicine, Cardiff CF144XN, UK.
| | | |
Collapse
|
43
|
Yamazaki D, Yamazaki T, Takeshima H. New molecular components supporting ryanodine receptor-mediated Ca2+ release: Roles of junctophilin and TRIC channel in embryonic cardiomyocytes. Pharmacol Ther 2009; 121:265-72. [DOI: 10.1016/j.pharmthera.2008.11.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Accepted: 11/07/2008] [Indexed: 01/01/2023]
|
44
|
Rigoard P, Buffenoir K, Wager M, Bauche S, Giot JP, Lapierre F. [Molecular architecture of the sarcoplasmic reticulum and its role in the ECC]. Neurochirurgie 2009; 55 Suppl 1:S83-91. [PMID: 19233437 DOI: 10.1016/j.neuchi.2008.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2008] [Accepted: 05/09/2008] [Indexed: 11/16/2022]
Abstract
The sarcoplasmic reticulum (SR) plays a fundamental role in excitation-contraction coupling, which propagates the electric signal conversion along the muscle fiber's plasmic membrane to a mechanical event manifested as a muscle contraction. It plays a crucial role in calcium homeostasis and intracellular calcium storage control (storage, liberation and uptake) necessary for fiber muscle contraction and then relaxation. These functions take place at the triad, made up of individualized SR subdomains where the protein-specific organization provides efficient and fast coupling. Ryanodine receptors (RyR) and dihydropyridine receptors (DHPR) mainly act in calcium exchanges in the SR. This particular structural and molecular architecture must be correlated to its functional specificity.
Collapse
Affiliation(s)
- P Rigoard
- Service de neurochirurgie, CHU La Milétrie, 2, rue de la Milétrie, BP 577, 86021 Poitiers cedex, France.
| | | | | | | | | | | |
Collapse
|
45
|
Takamori M. Autoantibodies against TRPC3 and ryanodine receptor in myasthenia gravis. J Neuroimmunol 2008; 200:142-4. [PMID: 18602703 DOI: 10.1016/j.jneuroim.2008.06.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2008] [Revised: 05/27/2008] [Accepted: 06/02/2008] [Indexed: 10/21/2022]
Abstract
The transient receptor potential canonical type-3 (TRPC3, receptor- and store-operated Ca(2+) influx channel) participates in skeletal muscle contraction; its functional interactions with ryanodine receptor-1 (RyR1) are independent of sarcoplasmic Ca(2+) content and dihydropyridine receptor. In 25 generalized myasthenia gravis (MG), we detected antibodies against human TRPC3 peptide in 9 patients (8 with thymoma and one with hyperplastic thymus) and those against human RyR1 peptides in 16 patients (15 with thymoma and one with hyperplastic thymus). Both antibodies were found in patients with more severe myasthenia and could contribute to the contractile abnormalities in MG.
Collapse
Affiliation(s)
- Masaharu Takamori
- Neurological Center, Kanazawa-Nishi Hospital, 6-15-41, Ekinishi-Honmachi, Kanazawa, Ishikawa-ken, 920-0025, Japan.
| |
Collapse
|
46
|
Laver DR. Ca2+ stores regulate ryanodine receptor Ca2+ release channels via luminal and cytosolic Ca2+ sites. Clin Exp Pharmacol Physiol 2007; 34:889-96. [PMID: 17645636 DOI: 10.1111/j.1440-1681.2007.04708.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
1. In muscle, intracellular calcium concentration, hence skeletal muscle force and cardiac output, is regulated by uptake and release of calcium from the sarcoplasmic reticulum. The ryanodine receptor (RyR) forms the calcium release channel in the sarcoplasmic reticulum. 2. The free [Ca2+] in the sarcoplasmic reticulum regulates the excitability of this store by stimulating the Ca2+ release channels in its membrane. This process involves Ca2+-sensing mechanisms on both the luminal and cytoplasmic sides of the RyR. In the cardiac RyR, these have been shown to be a luminal Ca2+ activation site (L-site; 60 micromol/L affinity), a cytoplasmic activation site (A-site; 0.9 micromol/L affinity) and a cytoplasmic Ca2+ inactivation site (I2-site; 1.2 micromol/L affinity). 3. Cardiac RyR activation by luminal Ca2+ occurs by a multistep process dubbed 'luminal-triggered Ca2+ feed-through'. Binding of Ca2+ to the L-site initiates brief (1 msec) openings at a rate of up to 10/s. Once the pore is open, luminal Ca2+ has access to the A-site (producing up to 30-fold prolongation of openings) and to the I2-site (causing inactivation at high levels of Ca2+ feed-through). 4. The present paper reviews the evidence for the principal aspects of the 'luminal-triggered Ca2+ feed-through' model, the properties of the various Ca2+-dependent gating mechanisms and their likely role in controlling sarcoplasmic reticulum (SR) Ca2+ release in cardiac muscle. 5. The model makes the following important predictions: (i) there will be a close link between luminal and cytoplasmic regulation of RyRs and any cofactor that prolongs channel openings triggered by cytoplasmic Ca2+ will also promote RyR activation by luminal Ca2+; (ii) luminal Mg2+ (1 mmol/L) is essential for the control of SR excitability in cardiac muscle by luminal Ca2+; and (iii) the different RyR isoforms in skeletal and cardiac muscle will be controlled quite differently by the luminal milieu. For example, Mg2+ in the SR lumen (approximately 1 mmol/L) can strongly inhibit RyR2 by competing with Ca2+ for the L-site, whereas RyR1 is not affected by luminal Mg2+.
Collapse
Affiliation(s)
- Derek R Laver
- School of Biomedical Sciences, University of Newcastle and Hunter Medical Research Institute, Callaghan, New South Wales, Australia.
| |
Collapse
|
47
|
Abstract
Ryanodine receptors (RyRs)/Ca2+ release channels, on the endoplasmic and sarcoplasmic reticulum of most cell types, are required for intracellular Ca2+ release involved in diverse cellular functions, including muscle contraction and neurotransmitter release. The large cytoplasmic domain of the RyR serves as a scaffold for proteins that bind to and modulate the channel's function and that comprise a macromolecular signaling complex. These proteins include calstabins [FK506-binding proteins (FKBPs)], calmodulin (CaM), phosphodiesterase, kinases, phosphatases, and their cognate targeting proteins. This review focuses on recent progress in the understanding of RyR regulation and disease mechanisms that are associated with channel dysfunction.
Collapse
Affiliation(s)
- Ran Zalk
- Department of Physiology and Cellular Biophysics, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA.
| | | | | |
Collapse
|
48
|
Laver DR. Regulation of ryanodine receptors from skeletal and cardiac muscle during rest and excitation. Clin Exp Pharmacol Physiol 2007; 33:1107-13. [PMID: 17042923 DOI: 10.1111/j.1440-1681.2006.04500.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
1. In muscle, intracellular calcium concentration, hence skeletal muscle force and cardiac output, is regulated by uptake and release of calcium from the sarcoplasmic reticulum (SR). The ryanodine receptor (RyR) forms the calcium release channel in the SR. 2. Calcium release through RyRs is modulated by a wide variety of endogenous molecules, including small diffusible ligands such as ATP, Ca2+ and Mg2+. The regulation of RyR channels by ATP, Ca2+ and Mg2+ is a complex interplay of several regulatory mechanisms, which are still being unravelled. Consequently, it is not clearly known how RyRs are regulated in resting muscle and during contraction. 3. The present paper reviews factors controlling the activity of RyRs in skeletal and cardiac muscle with an emphasis on mechanistic insights derived from single channel recording methods. 4. In addition, the nature of dihydropyridine receptor (DHPR) control of RyRs in skeletal muscle derived from experiments with peptide fragments of the DHPR II-III loop is reviewed. 5. Finally, recent experiments on coupled RyRs in lipid bilayers and their potential for resolving the elusive mechanisms controlling calcium release during cardiac contraction are discussed.
Collapse
Affiliation(s)
- D R Laver
- School of Biomedical Sciences, University of Newcastle and Hunter Medical Research Institute, Callaghan, New South Wales, Australia.
| |
Collapse
|
49
|
Kong H, Wang R, Chen W, Zhang L, Chen K, Shimoni Y, Duff HJ, Chen SRW. Skeletal and cardiac ryanodine receptors exhibit different responses to Ca2+ overload and luminal ca2+. Biophys J 2007; 92:2757-70. [PMID: 17259277 PMCID: PMC1831700 DOI: 10.1529/biophysj.106.100545] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Spontaneous Ca(2+) release occurs in cardiac cells during sarcoplasmic reticulum Ca(2+) overload, a process we refer to as store-overload-induced Ca(2+) release (SOICR). Unlike cardiac cells, skeletal muscle cells exhibit little SOICR activity. The molecular basis of this difference is not well defined. In this study, we investigated the SOICR properties of HEK293 cells expressing RyR1 or RyR2. We found that HEK293 cells expressing RyR2 exhibited robust SOICR activity, whereas no SOICR activity was observed in HEK293 cells expressing RyR1. However, in the presence of low concentrations of caffeine, SOICR could be triggered in these RyR1-expressing cells. At the single-channel level, we showed that RyR2 is much more sensitive to luminal Ca(2+) than RyR1. To identify the molecular determinants responsible for these differences, we constructed two chimeras between RyR1 and RyR2, N-RyR1(1-4006)/C-RyR2(3962-4968) and N-RyR2(1-3961)/C-RyR1(4007-5037). We found that replacing the C-terminal region of RyR1 with the corresponding region of RyR2 (N-RyR1/C-RyR2) dramatically enhanced the propensity for SOICR and the response to luminal Ca(2+), whereas replacing the C-terminal region of RyR2 with the corresponding region of RyR1 (N-RyR2/C-RyR1) reduced the propensity for SOICR and the luminal Ca(2+) response. These observations indicate that the C-terminal region of RyR is a critical determinant of both SOICR and the response to luminal Ca(2+). These chimeric studies also reveal that the N-terminal region of RyR plays an important role in regulating SOICR and luminal Ca(2+) response. Taken together, our results demonstrate that RyR1 differs markedly from RyR2 with respect to their responses to Ca(2+) overload and luminal Ca(2+), and suggest that the lack of spontaneous Ca(2+) release in skeletal muscle cells is, in part, attributable to the unique intrinsic properties of RyR1.
Collapse
Affiliation(s)
- Huihui Kong
- Cardiovascular Research Group, Department of Physiology and Biophysics, and Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta, Canada
| | | | | | | | | | | | | | | |
Collapse
|
50
|
Abstract
The ryanodine receptor has been mainly regarded as the Ca2+ release channel from sarcoplasmic reticulum controlling skeletal and cardiac muscle contraction. However, many studies have shown that it is widely expressed, with functions not restricted to muscular contraction. This study examined whether ryanodine receptor plays a role in calcium signaling in the liver. RT-PCR analysis of isolated hepatocytes showed expression of a truncated type 1 ryanodine receptor, but no type 2 or type 3 message was detected. We also detected binding sites for [3H]ryanodine in the microsomal cellular fraction and in permeabilized hepatocytes. This binding was displaced by caffeine and dantrolene, but not by ruthenium red, heparin or cyclic ADP-Ribose. Ryanodine, by itself, did not trigger Ca2+ oscillations in either primary cultured hepatocytes or hepatocytes within the intact perfused rat liver. In both preparations, however, ryanodine significantly increased the frequency of the cytosolic free [Ca2+] oscillations evoked by an alpha1 adrenergic receptor agonist. Experiments in permeabilized hepatocytes showed that both ryanodine and cyclic ADP-ribose evoked a slow Ca2+ leak from intracellular stores and were able to increase the Ca2+-released response to a subthreshold dose of inositol 1,4,5-trisphosphate. Our findings suggest the presence of a novel truncated form of the type 1 ryanodine receptor in rat hepatocytes. Ryanodine modulates the pattern of cytosolic free [Ca2+] oscillations by increasing oscillation frequency. We propose that the Ca2+ released from ryanodine receptors on the endoplasmic reticulum provides an increased pool of Ca2+ for positive feedback on inositol 1,4,5-trisphosphate receptors.
Collapse
Affiliation(s)
- Nicola Pierobon
- Department of Pharmacology and Physiology, University of Medicine and Dentistry of New Jersey, Newark, New Jersey 07103, USA
| | | | | | | |
Collapse
|