1
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Yang W, Tian R, Zhu Y, Huang P, Ma X, Meng X, Dai W, Tao Y, Chen D, Zhang J, Lu J, Xie H, Jian X, Yang Z, Wang R. Paraquat is an agonist of STIM1 and increases intracellular calcium levels. Commun Biol 2022; 5:1151. [PMID: 36310238 PMCID: PMC9618025 DOI: 10.1038/s42003-022-04130-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 10/18/2022] [Indexed: 11/09/2022] Open
Abstract
Paraquat (PQ) is an efficient herbicide but leads to high mortality with no antidote in mammals. PQ produces reactive oxygen species (ROS), leading to epithelial-mesenchymal transition (EMT) for pulmonary fibrosis in type II alveolar (AT II) cells. Intriguingly, strategies reducing ROS exhibit limited therapeutic effects, indicating other targets existing for PQ toxicity. Herein we report that PQ is also an agonist for STIM1 that increases intracellular calcium levels. Particularly, PQ promotes STIM1 puncta formation and association with TRPC1 or ORAI for extracellular calcium entry and thus intracellular calcium influx. Further studies reveal the importance of P584&Y586 residues in STIM1 for PQ association that facilitates STIM1 binding to TRPC1. Consequently, the STIM1-TRPC1 route facilitates PQ-induced EMT for pulmonary fibrosis as well as cell death. Our results demonstrate that PQ is an agonist of STIM1 that induces extracellular calcium entry, increases intracellular calcium levels, and thus promotes EMT in AT II cells.
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Affiliation(s)
- Wenyu Yang
- Department of Critical Care Medicine, Shanghai General Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, 201620, China
| | - Rui Tian
- Department of Critical Care Medicine, Shanghai General Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, 201620, China
| | - Yong Zhu
- Department of Critical Care Medicine, Shanghai General Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, 201620, China
| | - Peijie Huang
- Department of Critical Care Medicine, Shanghai General Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, 201620, China
| | - Xinrun Ma
- Precision Research Center for Refractory Diseases, Shanghai General Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, 201620, China
| | - Xiaoxiao Meng
- Department of Critical Care Medicine, Shanghai General Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, 201620, China
| | - Wentao Dai
- Shanghai Center for Bioinformation Technology, Shanghai Academy of Science and Technology, Shanghai, 201203, China
| | - Yiming Tao
- Department of Poisoning and Occupational Diseases, Emergency, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, China
| | - Daonan Chen
- Department of Critical Care Medicine, Shanghai General Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, 201620, China
| | - Jiaxiang Zhang
- Department of Critical Care Medicine, Shanghai General Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, 201620, China
| | - Jian Lu
- Department of Critical Care Medicine, Shanghai General Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, 201620, China
| | - Hui Xie
- Department of Critical Care Medicine, Shanghai General Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, 201620, China
| | - Xiangdong Jian
- Department of Poisoning and Occupational Diseases, Emergency, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, China.
| | - Zhengfeng Yang
- Department of Critical Care Medicine, Shanghai General Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, 201620, China.
- Precision Research Center for Refractory Diseases, Shanghai General Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, 201620, China.
| | - Ruilan Wang
- Department of Critical Care Medicine, Shanghai General Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, 201620, China.
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2
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Alteration of STIM1/Orai1-Mediated SOCE in Skeletal Muscle: Impact in Genetic Muscle Diseases and Beyond. Cells 2021; 10:cells10102722. [PMID: 34685702 PMCID: PMC8534495 DOI: 10.3390/cells10102722] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 10/05/2021] [Accepted: 10/08/2021] [Indexed: 02/08/2023] Open
Abstract
Intracellular Ca2+ ions represent a signaling mediator that plays a critical role in regulating different muscular cellular processes. Ca2+ homeostasis preservation is essential for maintaining skeletal muscle structure and function. Store-operated Ca2+ entry (SOCE), a Ca2+-entry process activated by depletion of intracellular stores contributing to the regulation of various function in many cell types, is pivotal to ensure a proper Ca2+ homeostasis in muscle fibers. It is coordinated by STIM1, the main Ca2+ sensor located in the sarcoplasmic reticulum, and ORAI1 protein, a Ca2+-permeable channel located on transverse tubules. It is commonly accepted that Ca2+ entry via SOCE has the crucial role in short- and long-term muscle function, regulating and adapting many cellular processes including muscle contractility, postnatal development, myofiber phenotype and plasticity. Lack or mutations of STIM1 and/or Orai1 and the consequent SOCE alteration have been associated with serious consequences for muscle function. Importantly, evidence suggests that SOCE alteration can trigger a change of intracellular Ca2+ signaling in skeletal muscle, participating in the pathogenesis of different progressive muscle diseases such as tubular aggregate myopathy, muscular dystrophy, cachexia, and sarcopenia. This review provides a brief overview of the molecular mechanisms underlying STIM1/Orai1-dependent SOCE in skeletal muscle, focusing on how SOCE alteration could contribute to skeletal muscle wasting disorders and on how SOCE components could represent pharmacological targets with high therapeutic potential.
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3
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Burgos M, Philippe R, Antigny F, Buscaglia P, Masson E, Mukherjee S, Dubar P, Le Maréchal C, Campeotto F, Lebonvallet N, Frieden M, Llopis J, Domingo B, Stathopulos PB, Ikura M, Brooks W, Guida W, Chen JM, Ferec C, Capiod T, Mignen O. The p.E152K-STIM1 mutation deregulates Ca 2+ signaling contributing to chronic pancreatitis. J Cell Sci 2021; 134:jcs.244012. [PMID: 33468626 DOI: 10.1242/jcs.244012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 12/24/2020] [Indexed: 11/20/2022] Open
Abstract
Since deregulation of intracellular Ca2+ can lead to intracellular trypsin activation, and stromal interaction molecule-1 (STIM1) protein is the main regulator of Ca2+ homeostasis in pancreatic acinar cells, we explored the Ca2+ signaling in 37 STIM1 variants found in three pancreatitis patient cohorts. Extensive functional analysis of one particular variant, p.E152K, identified in three patients, provided a plausible link between dysregulated Ca2+ signaling within pancreatic acinar cells and chronic pancreatitis susceptibility. Specifically, p.E152K, located within the STIM1 EF-hand and sterile α-motif domain, increased the release of Ca2+ from the endoplasmic reticulum in patient-derived fibroblasts and transfected HEK293T cells. This event was mediated by altered STIM1-sarco/endoplasmic reticulum calcium transport ATPase (SERCA) conformational change and enhanced SERCA pump activity leading to increased store-operated Ca2+ entry (SOCE). In pancreatic AR42J cells expressing the p.E152K variant, Ca2+ signaling perturbations correlated with defects in trypsin activation and secretion, and increased cytotoxicity after cholecystokinin stimulation.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Miguel Burgos
- Université de Brest, INSERM, EFS, UMR 1078, GGB, F-29200 Brest, France .,Centro Regional de Investigaciones Biomédicas (CRIB) and Facultad de Medicina de Albacete, Universidad de Castilla-La Mancha, 02002 Albacete, Spain.,Complejo Hospitalario Universitario de Albacete (UI-CHUA), 02002 Albacete, Spain
| | - Reginald Philippe
- Université de Brest, INSERM, EFS, UMR 1078, GGB, F-29200 Brest, France
| | - Fabrice Antigny
- Univ. Paris-Sud, Faculté de Médecine, Université Paris-Saclay, 94270 Le Kremlin Bicêtre, France.,Inserm UMR_S 999, Hôpital Marie Lannelongue, 92350 Le Plessis Robinson, France.,Department of Cell Physiology and Metabolism, Geneva Medical Center, CH-1211 Geneva, Switzerland
| | - Paul Buscaglia
- Université de Brest, INSERM, EFS, UMR 1078, GGB, F-29200 Brest, France.,UMR1227, Lymphocytes B et Autoimmunité, Université de Brest, INSERM, CHU de Brest, BP824, F29609 Brest, France
| | - Emmanuelle Masson
- Université de Brest, INSERM, EFS, UMR 1078, GGB, F-29200 Brest, France
| | - Sreya Mukherjee
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA
| | - Pauline Dubar
- Université de Brest, INSERM, EFS, UMR 1078, GGB, F-29200 Brest, France
| | | | - Florence Campeotto
- Hôpital Necker, AP-HP, Service de Gastroentérologie et Explorations Fonctionnelles Digestives Pédiatriques, Paris Descartes-Sorbonne Paris Cité Université, Institut Imagine, 75015 Paris, France
| | - Nicolas Lebonvallet
- Laboratory of Interactions Keratinocytes Neurons (EA4685), University of Western Brittany, F-29200 Brest, France
| | - Maud Frieden
- Department of Cell Physiology and Metabolism, Geneva Medical Center, CH-1211 Geneva, Switzerland
| | - Juan Llopis
- Centro Regional de Investigaciones Biomédicas (CRIB) and Facultad de Medicina de Albacete, Universidad de Castilla-La Mancha, 02002 Albacete, Spain
| | - Beatriz Domingo
- Centro Regional de Investigaciones Biomédicas (CRIB) and Facultad de Medicina de Albacete, Universidad de Castilla-La Mancha, 02002 Albacete, Spain
| | - Peter B Stathopulos
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, London, ON N6A 5C1, Canada
| | - Mitsuhiko Ikura
- Department of Medical Biophysics, University of Toronto, Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 2M9, Canada
| | - Wesley Brooks
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA
| | - Wayne Guida
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA
| | - Jian-Min Chen
- Université de Brest, INSERM, EFS, UMR 1078, GGB, F-29200 Brest, France
| | - Claude Ferec
- Université de Brest, INSERM, EFS, UMR 1078, GGB, F-29200 Brest, France
| | - Thierry Capiod
- INSERM Unit 1151, Institut Necker Enfants Malades (INEM), Université Paris Descartes, Paris 75014, France
| | - Olivier Mignen
- Université de Brest, INSERM, EFS, UMR 1078, GGB, F-29200 Brest, France .,UMR1227, Lymphocytes B et Autoimmunité, Université de Brest, INSERM, CHU de Brest, BP824, F29609 Brest, France
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4
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Ma G, He L, Liu S, Xie J, Huang Z, Jing J, Lee YT, Wang R, Luo H, Han W, Huang Y, Zhou Y. Optogenetic engineering to probe the molecular choreography of STIM1-mediated cell signaling. Nat Commun 2020; 11:1039. [PMID: 32098964 PMCID: PMC7042325 DOI: 10.1038/s41467-020-14841-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 02/06/2020] [Indexed: 02/07/2023] Open
Abstract
Genetically encoded photoswitches have enabled spatial and temporal control of cellular events to achieve tailored functions in living cells, but their applications to probe the structure-function relations of signaling proteins are still underexplored. We illustrate herein the incorporation of various blue light-responsive photoreceptors into modular domains of the stromal interaction molecule 1 (STIM1) to manipulate protein activity and faithfully recapitulate STIM1-mediated signaling events. Capitalizing on these optogenetic tools, we identify the molecular determinants required to mediate protein oligomerization, intramolecular conformational switch, and protein-target interactions. In parallel, we have applied these synthetic devices to enable light-inducible gating of calcium channels, conformational switch, dynamic protein-microtubule interactions and assembly of membrane contact sites in a reversible manner. Our optogenetic engineering approach can be broadly applied to aid the mechanistic dissection of cell signaling, as well as non-invasive interrogation of physiological processes with high precision. Optogenetic tools have been used to control cellular behaviours but their use to probe structure-function relations of signalling proteins are underexplored. Here the authors engineer optogenetic modules into STIM1 to dissect molecular details of STIM1-mediated signalling and control various cellular events.
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Affiliation(s)
- Guolin Ma
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M University, Houston, TX, 77030, USA
| | - Lian He
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M University, Houston, TX, 77030, USA
| | - Shuzhong Liu
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M University, Houston, TX, 77030, USA.,Department of Gastroenterology, Key Laboratory of Hubei Province for Digestive System Disease, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Jiansheng Xie
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M University, Houston, TX, 77030, USA.,Department of Medical Oncology, Laboratory of Cancer Biology, Institute of Clinical Science, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Zixian Huang
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M University, Houston, TX, 77030, USA.,Department of Oral and Maxillofacial Surgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, 510120, China
| | - Ji Jing
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M University, Houston, TX, 77030, USA
| | - Yi-Tsang Lee
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M University, Houston, TX, 77030, USA
| | - Rui Wang
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M University, Houston, TX, 77030, USA
| | - Hesheng Luo
- Department of Gastroenterology, Key Laboratory of Hubei Province for Digestive System Disease, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Weidong Han
- Department of Medical Oncology, Laboratory of Cancer Biology, Institute of Clinical Science, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
| | - Yun Huang
- Center for Epigenetics and Disease Prevention, Institute of Biosciences and Technology, Texas A&M University, Houston, TX, 77030, USA.
| | - Yubin Zhou
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M University, Houston, TX, 77030, USA. .,Department of Translational Medical Sciences, College of Medicine, Texas A&M University, Houston, TX, 77030, USA.
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5
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Bhuvaneshwari S, Sankaranarayanan K. Structural and Mechanistic Insights of CRAC Channel as a Drug Target in Autoimmune Disorder. Curr Drug Targets 2019; 21:55-75. [PMID: 31556856 DOI: 10.2174/1389450120666190926150258] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 08/20/2019] [Accepted: 08/20/2019] [Indexed: 01/17/2023]
Abstract
BACKGROUND Calcium (Ca2+) ion is a major intracellular signaling messenger, controlling a diverse array of cellular functions like gene expression, secretion, cell growth, proliferation, and apoptosis. The major mechanism controlling this Ca2+ homeostasis is store-operated Ca2+ release-activated Ca2+ (CRAC) channels. CRAC channels are integral membrane protein majorly constituted via two proteins, the stromal interaction molecule (STIM) and ORAI. Following Ca2+ depletion in the Endoplasmic reticulum (ER) store, STIM1 interacts with ORAI1 and leads to the opening of the CRAC channel gate and consequently allows the influx of Ca2+ ions. A plethora of studies report that aberrant CRAC channel activity due to Loss- or gain-of-function mutations in ORAI1 and STIM1 disturbs this Ca2+ homeostasis and causes several autoimmune disorders. Hence, it clearly indicates that the therapeutic target of CRAC channels provides the space for a new approach to treat autoimmune disorders. OBJECTIVE This review aims to provide the key structural and mechanical insights of STIM1, ORAI1 and other molecular modulators involved in CRAC channel regulation. RESULTS AND CONCLUSION Understanding the structure and function of the protein is the foremost step towards improving the effective target specificity by limiting their potential side effects. Herein, the review mainly focusses on the structural underpinnings of the CRAC channel gating mechanism along with its biophysical properties that would provide the solid foundation to aid the development of novel targeted drugs for an autoimmune disorder. Finally, the immune deficiencies caused due to mutations in CRAC channel and currently used pharmacological blockers with their limitation are briefly summarized.
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Affiliation(s)
- Sampath Bhuvaneshwari
- Ion Channel Biology Laboratory, AU-KBC Research Centre, Madras Institute of Technology, Anna University, Chrompet, Chennai -600 044, India
| | - Kavitha Sankaranarayanan
- Ion Channel Biology Laboratory, AU-KBC Research Centre, Madras Institute of Technology, Anna University, Chrompet, Chennai -600 044, India
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6
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Yang Z, Yan H, Dai W, Jing J, Yang Y, Mahajan S, Zhou Y, Li W, Macaubas C, Mellins ED, Shih CC, Fitzpatrick JAJ, Faccio R. Tmem178 negatively regulates store-operated calcium entry in myeloid cells via association with STIM1. J Autoimmun 2019; 101:94-108. [PMID: 31018906 DOI: 10.1016/j.jaut.2019.04.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 04/09/2019] [Accepted: 04/12/2019] [Indexed: 12/27/2022]
Abstract
Store-operated calcium entry (SOCE) modulates cytosolic calcium in multiple cells. Endoplasmic reticulum (ER)-localized STIM1 and plasma membrane (PM)-localized ORAI1 are two main components of SOCE. STIM1:ORAI1 association requires STIM1 oligomerization, its re-distribution to ER-PM junctions, and puncta formation. However, little is known about the negative regulation of these steps to prevent calcium overload. Here, we identified Tmem178 as a negative modulator of STIM1 puncta formation in myeloid cells. Using site-directed mutagenesis, co-immunoprecipitation assays and FRET imaging, we determined that Tmem178:STIM1 association occurs via their transmembrane motifs. Mutants that increase Tmem178:STIM1 association reduce STIM1 puncta formation, SOCE activation, impair inflammatory cytokine production in macrophages and osteoclastogenesis. Mutants that reduce Tmem178:STIM1 association reverse these effects. Furthermore, exposure to plasma from arthritic patients decreases Tmem178 expression, enhances SOCE activation and cytoplasmic calcium. In conclusion, Tmem178 modulates the rate-limiting step of STIM1 puncta formation and therefore controls SOCE in inflammatory conditions.
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Affiliation(s)
- Zhengfeng Yang
- Department of Orthopaedics, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Hui Yan
- Department of Orthopaedics, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Wentao Dai
- Shanghai Center for Bioinformation Technology & Shanghai Engineering Research Center of Pharmaceutical Translation, Shanghai Industrial Technology Institute, 1278 Keyuan Road, Shanghai, 201203, China
| | - Ji Jing
- Institute of Biosciences and Technology, Texas A&M University College of Medicine, Houston, TX 77030, USA
| | - Yihu Yang
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA
| | - Sahil Mahajan
- Department of Orthopaedics, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Yubin Zhou
- Institute of Biosciences and Technology, Texas A&M University College of Medicine, Houston, TX 77030, USA
| | - Weikai Li
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA
| | - Claudia Macaubas
- Department of Pediatrics, Program in Immunology, Stanford University, Stanford, CA 94305, USA
| | - Elizabeth D Mellins
- Department of Pediatrics, Program in Immunology, Stanford University, Stanford, CA 94305, USA
| | - Chien-Cheng Shih
- Washington University Center for Cellular Imaging, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - James A J Fitzpatrick
- Washington University Center for Cellular Imaging, Washington University School of Medicine, St. Louis, MO, 63110, USA; Department of Cell Biology & Physiology, Washington University School of Medicine, St. Louis, MO, USA; Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, USA; Department of Biomedical Engineering, Washington University, St. Louis, MO, USA
| | - Roberta Faccio
- Department of Orthopaedics, Washington University School of Medicine, St. Louis, MO, 63110, USA; Shriners Hospitals for Children, St. Louis MO, USA.
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7
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Bulla M, Gyimesi G, Kim JH, Bhardwaj R, Hediger MA, Frieden M, Demaurex N. ORAI1 channel gating and selectivity is differentially altered by natural mutations in the first or third transmembrane domain. J Physiol 2018; 597:561-582. [PMID: 30382595 PMCID: PMC6332830 DOI: 10.1113/jp277079] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 10/31/2018] [Indexed: 12/12/2022] Open
Abstract
KEY POINTS Gain-of-function mutations in the highly selective Ca2+ channel ORAI1 cause tubular aggregate myopathy (TAM) characterized by muscular pain, weakness and cramping. TAM-associated mutations in ORAI1 first and third transmembrane domain facilitate channel opening by STIM1, causing constitutive Ca2+ influx and increasing the currents evoked by Ca2+ store depletion. Mutation V107M additionally decreases the channel selectivity for Ca2+ ions and its inhibition by acidic pH, while mutation T184M does not alter the channel sensitivity to pH or to reactive oxygen species. The ORAI blocker GSK-7975A prevents the constitutive activity of TAM-associated channels and might be used in therapy for patients suffering from TAM. ABSTRACT Skeletal muscle differentiation relies on store-operated Ca2+ entry (SOCE) mediated by STIM proteins linking the depletion of endoplasmic/sarcoplasmic reticulum Ca2+ stores to the activation of membrane Ca2+ -permeable ORAI channels. Gain-of-function mutations in STIM1 or ORAI1 isoforms cause tubular aggregate myopathy (TAM), a skeletal muscle disorder with muscular pain, weakness and cramping. Here, we characterize two overactive ORAI1 mutants from patients with TAM: V107M and T184M, located in the first and third transmembrane domain of the channel. When ectopically expressed in HEK-293T cells or human primary myoblasts, the mutated channels increased basal and store-operated Ca2+ entry. The constitutive activity of V107M, L138F, T184M and P245L mutants was prevented by low concentrations of GSK-7975A while the G98S mutant was resistant to inhibition. Electrophysiological recordings confirmed ORAI1-V107M constitutive activity and revealed larger STIM1-gated V107M- and T184M-mediated currents with conserved fast and slow Ca2+ -dependent inactivation. Mutation V107M altered the channel selectivity for Ca2+ ions and conferred resistance to acidic inhibition. Ca2+ imaging and molecular dynamics simulations showed a preserved sensitivity of T184M to the negative regulation by reactive oxygen species. Both mutants were able to mediate SOCE in Stim1-/- /Stim2-/- mouse embryonic fibroblasts expressing the binding-deficient STIM1-F394H mutant, indicating a higher sensitivity for STIM1-mediated gating, with ORAI1-T184M gain-of-function being strictly dependent on STIM1. These findings provide new insights into the permeation and regulatory properties of ORAI1 mutants that might translate into therapies against diseases with gain-of-function mutations in ORAI1.
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Affiliation(s)
- M Bulla
- Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - G Gyimesi
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland
| | - J H Kim
- Departments of Physiology and Global Medical Science, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.,Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - R Bhardwaj
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland
| | - M A Hediger
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland
| | - M Frieden
- Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - N Demaurex
- Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
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8
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Li X, Wu G, Yang Y, Fu S, Liu X, Kang H, Yang X, Su XC, Shen Y. Calmodulin dissociates the STIM1-Orai1 complex and STIM1 oligomers. Nat Commun 2017; 8:1042. [PMID: 29051492 PMCID: PMC5648805 DOI: 10.1038/s41467-017-01135-w] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Accepted: 08/22/2017] [Indexed: 01/20/2023] Open
Abstract
Store-operated calcium entry (SOCE) is a major pathway for calcium ions influx into cells and has a critical role in various cell functions. Here we demonstrate that calcium-bound calmodulin (Ca2+-CaM) binds to the core region of activated STIM1. This interaction facilitates slow Ca2+-dependent inactivation after Orai1 channel activation by wild-type STIM1 or a constitutively active STIM1 mutant. We define the CaM-binding site in STIM1, which is adjacent to the STIM1-Orai1 coupling region. The binding of Ca2+-CaM to activated STIM1 disrupts the STIM1-Orai1 complex and also disassembles STIM1 oligomer. Based on these results we propose a model for the calcium-bound CaM-regulated deactivation of SOCE.
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Affiliation(s)
- Xin Li
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin, 300071, China
| | - Guangyan Wu
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin, 300071, China
| | - Yin Yang
- State Key Laboratory of Elemento-Organic Chemistry and College of Chemistry, Nankai University, 94 Weijin Road, Tianjin, 300071, China
| | - Shijuan Fu
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin, 300071, China
| | - Xiaofen Liu
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin, 300071, China
| | - Huimin Kang
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin, 300071, China
| | - Xue Yang
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin, 300071, China.
| | - Xun-Cheng Su
- State Key Laboratory of Elemento-Organic Chemistry and College of Chemistry, Nankai University, 94 Weijin Road, Tianjin, 300071, China. .,Synergetic Innovation Center of Chemical Science and Engineering, 94 Weijin Road, Tianjin, 300071, China.
| | - Yuequan Shen
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin, 300071, China. .,Synergetic Innovation Center of Chemical Science and Engineering, 94 Weijin Road, Tianjin, 300071, China.
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9
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Characterization of the ER-Targeted Low Affinity Ca(2+) Probe D4ER. SENSORS 2016; 16:s16091419. [PMID: 27598166 PMCID: PMC5038697 DOI: 10.3390/s16091419] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 08/26/2016] [Accepted: 08/30/2016] [Indexed: 12/17/2022]
Abstract
Calcium ion (Ca2+) is a ubiquitous intracellular messenger and changes in its concentration impact on nearly every aspect of cell life. Endoplasmic reticulum (ER) represents the major intracellular Ca2+ store and the free Ca2+ concentration ([Ca2+]) within its lumen ([Ca2+]ER) can reach levels higher than 1 mM. Several genetically-encoded ER-targeted Ca2+ sensors have been developed over the last years. However, most of them are non-ratiometric and, thus, their signal is difficult to calibrate in live cells and is affected by shifts in the focal plane and artifactual movements of the sample. On the other hand, existing ratiometric Ca2+ probes are plagued by different drawbacks, such as a double dissociation constant (Kd) for Ca2+, low dynamic range, and an affinity for the cation that is too high for the levels of [Ca2+] in the ER lumen. Here, we report the characterization of a recently generated ER-targeted, Förster resonance energy transfer (FRET)-based, Cameleon probe, named D4ER, characterized by suitable Ca2+ affinity and dynamic range for monitoring [Ca2+] variations within the ER. As an example, resting [Ca2+]ER have been evaluated in a known paradigm of altered ER Ca2+ homeostasis, i.e., in cells expressing a mutated form of the familial Alzheimer’s Disease-linked protein Presenilin 2 (PS2). The lower Ca2+ affinity of the D4ER probe, compared to that of the previously generated D1ER, allowed the detection of a conspicuous, more clear-cut, reduction in ER Ca2+ content in cells expressing mutated PS2, compared to controls.
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The Calcium Entry-Calcium Refilling Coupling. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 898:333-52. [DOI: 10.1007/978-3-319-26974-0_14] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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11
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Abstract
Ca(2+) release-activated Ca(2+) (CRAC) channels mediate a specific form of Ca(2+) influx called store-operated Ca(2+) entry (SOCE) that contributes to the function of many cell types. CRAC channels are composed of ORAI1 proteins located in the plasma membrane, which form its ion-conducting pore. ORAI1 channels are activated by stromal interaction molecule (STIM) 1 and STIM2 located in the endoplasmic reticulum. Loss- and gain-of-function gene mutations in ORAI1 and STIM1 in human patients cause distinct disease syndromes. CRAC channelopathy is caused by loss-of-function mutations in ORAI1 and STIM1 that abolish CRAC channel function and SOCE; it is characterized by severe combined immunodeficiency (SCID)-like disease, autoimmunity, muscular hypotonia, and ectodermal dysplasia, with defects in sweat gland function and dental enamel formation. The latter defect emphasizes an important role of CRAC channels in tooth development. By contrast, autosomal dominant gain-of-function mutations in ORAI1 and STIM1 result in constitutive CRAC channel activation, SOCE, and increased intracellular Ca(2+) levels that are associated with an overlapping spectrum of diseases, including nonsyndromic tubular aggregate myopathy (TAM) and York platelet and Stormorken syndromes. The latter two syndromes are defined, besides myopathy, by thrombocytopenia, thrombopathy, and bleeding diathesis. The fact that myopathy results from both loss- and gain-of-function mutations in ORAI1 and STIM1 highlights the importance of CRAC channels for Ca(2+) homeostasis in skeletal muscle function. The cellular dysfunction and clinical disease spectrum observed in mutant patients provide important information about the molecular regulation of ORAI1 and STIM1 proteins and the role of CRAC channels in human physiology.
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Affiliation(s)
- Rodrigo S Lacruz
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, New York
| | - Stefan Feske
- Department of Pathology, New York University School of Medicine, New York, New York
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Abstract
Store-operated calcium channels (SOCs) are a major pathway for calcium signaling in virtually all metozoan cells and serve a wide variety of functions ranging from gene expression, motility, and secretion to tissue and organ development and the immune response. SOCs are activated by the depletion of Ca(2+) from the endoplasmic reticulum (ER), triggered physiologically through stimulation of a diverse set of surface receptors. Over 15 years after the first characterization of SOCs through electrophysiology, the identification of the STIM proteins as ER Ca(2+) sensors and the Orai proteins as store-operated channels has enabled rapid progress in understanding the unique mechanism of store-operate calcium entry (SOCE). Depletion of Ca(2+) from the ER causes STIM to accumulate at ER-plasma membrane (PM) junctions where it traps and activates Orai channels diffusing in the closely apposed PM. Mutagenesis studies combined with recent structural insights about STIM and Orai proteins are now beginning to reveal the molecular underpinnings of these choreographic events. This review describes the major experimental advances underlying our current understanding of how ER Ca(2+) depletion is coupled to the activation of SOCs. Particular emphasis is placed on the molecular mechanisms of STIM and Orai activation, Orai channel properties, modulation of STIM and Orai function, pharmacological inhibitors of SOCE, and the functions of STIM and Orai in physiology and disease.
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Affiliation(s)
- Murali Prakriya
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois; and Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California
| | - Richard S Lewis
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois; and Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California
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Miederer AM, Alansary D, Schwär G, Lee PH, Jung M, Helms V, Niemeyer BA. A STIM2 splice variant negatively regulates store-operated calcium entry. Nat Commun 2015; 6:6899. [PMID: 25896806 PMCID: PMC4411291 DOI: 10.1038/ncomms7899] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 03/11/2015] [Indexed: 02/01/2023] Open
Abstract
Cellular homeostasis relies upon precise regulation of Ca(2+) concentration. Stromal interaction molecule (STIM) proteins regulate store-operated calcium entry (SOCE) by sensing Ca(2+) concentration in the ER and forming oligomers to trigger Ca(2+) entry through plasma membrane-localized Orai1 channels. Here we characterize a STIM2 splice variant, STIM2.1, which retains an additional exon within the region encoding the channel-activating domain. Expression of STIM2.1 is ubiquitous but its abundance relative to the more common STIM2.2 variant is dependent upon cell type and highest in naive T cells. STIM2.1 knockdown increases SOCE in naive CD4(+) T cells, whereas knockdown of STIM2.2 decreases SOCE. Conversely, overexpression of STIM2.1, but not STIM2.2, decreases SOCE, indicating its inhibitory role. STIM2.1 interaction with Orai1 is impaired and prevents Orai1 activation, but STIM2.1 shows increased affinity towards calmodulin. Our results imply STIM2.1 as an additional player tuning Orai1 activation in vivo.
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Affiliation(s)
- Anna-Maria Miederer
- Molecular Biophysics, Center for Integrative Physiology and Molecular Medicine (CIPMM), School of Medicine, Saarland University, Building 48, Homburg 66421, Germany
| | - Dalia Alansary
- Molecular Biophysics, Center for Integrative Physiology and Molecular Medicine (CIPMM), School of Medicine, Saarland University, Building 48, Homburg 66421, Germany
| | - Gertrud Schwär
- Molecular Biophysics, Center for Integrative Physiology and Molecular Medicine (CIPMM), School of Medicine, Saarland University, Building 48, Homburg 66421, Germany
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine (CIPMM), School of Medicine, Saarland University, Homburg 66421, Germany
| | - Po-Hsien Lee
- Center for Bioinformatics, Saarland University, Campus E2 1, R. 315, PO Box 151150, Saarbrücken 66041, Germany
| | - Martin Jung
- Department of Medical Biochemistry and Molecular Biology, Saarland University, Building 44, Homburg 66421, Germany
| | - Volkhard Helms
- Center for Bioinformatics, Saarland University, Campus E2 1, R. 315, PO Box 151150, Saarbrücken 66041, Germany
| | - Barbara A. Niemeyer
- Molecular Biophysics, Center for Integrative Physiology and Molecular Medicine (CIPMM), School of Medicine, Saarland University, Building 48, Homburg 66421, Germany
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Pászty K, Caride AJ, Bajzer Ž, Offord CP, Padányi R, Hegedűs L, Varga K, Strehler EE, Enyedi A. Plasma membrane Ca2+-ATPases can shape the pattern of Ca2+transients induced by store-operated Ca2+entry. Sci Signal 2015; 8:ra19. [DOI: 10.1126/scisignal.2005672] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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15
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Philippe R, Antigny F, Buscaglia P, Norez C, Becq F, Frieden M, Mignen O. SERCA and PMCA pumps contribute to the deregulation of Ca2+ homeostasis in human CF epithelial cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:892-903. [PMID: 25661196 DOI: 10.1016/j.bbamcr.2015.01.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 01/12/2015] [Accepted: 01/15/2015] [Indexed: 11/26/2022]
Abstract
Cystic Fibrosis (CF) disease is caused by mutations in the CFTR gene (CF transmembrane conductance regulator). F508 deletion is the most represented mutation, and F508del-CFTR is absent of plasma membrane and accumulates into the endoplasmic reticulum (ER) compartment. Using specific Ca2+ genetics cameleon probes, we showed in the human bronchial CF epithelial cell line CFBE that ER Ca2+ concentration was strongly increased compared to non-CF (16HBE) cells, and normalized by the F508del-CFTR corrector agent, VX-809. We also showed that ER F508del-CFTR retention increases SERCA (Sarcoplasmic/Reticulum Ca2+ ATPase) pump activity whereas PMCA (Plasma Membrane Ca2+ ATPase) activities were reduced in these CF cells compared to corrected CF cells (VX-809) and non-CF cells. We are showing for the first time CFTR/SERCA and CFTR/PMCA interactions that are modulated in CF cells and could explain part of Ca2+ homeostasis deregulation due to mislocalization of F508del-CFTR. Using ER or mitochondria genetics Ca2+ probes, we are showing that ER Ca2+ content, mitochondrial Ca2+ uptake, SERCA and PMCA pump, activities are strongly affected by the localization of F508del-CFTR protein.
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Affiliation(s)
- Réginald Philippe
- NSERM U1078, Université Bretagne Occidentale, 22 Avenue Camille Desmoulins, 29200 Brest, France
| | - Fabrice Antigny
- Department of Basic Neurosciences, 1, Rue Michel Servet, 1211 Geneva 4, Switzerland
| | - Paul Buscaglia
- NSERM U1078, Université Bretagne Occidentale, 22 Avenue Camille Desmoulins, 29200 Brest, France
| | - Caroline Norez
- Laboratoire Signalisation et Transport Ioniques Membranaires, Université Poitiers-CNRS Pole Biologie Santé, 1 rue George Bonnet, 86073 Poitiers Cedex, France
| | - Frédéric Becq
- Laboratoire Signalisation et Transport Ioniques Membranaires, Université Poitiers-CNRS Pole Biologie Santé, 1 rue George Bonnet, 86073 Poitiers Cedex, France
| | - Maud Frieden
- Cell Physiology and Metabolism University of Geneva Medical School, 1, Rue Michel Servet, 1211 Geneva 4, Switzerland
| | - Olivier Mignen
- NSERM U1078, Université Bretagne Occidentale, 22 Avenue Camille Desmoulins, 29200 Brest, France.
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16
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Shim AHR, Tirado-Lee L, Prakriya M. Structural and functional mechanisms of CRAC channel regulation. J Mol Biol 2014; 427:77-93. [PMID: 25284754 DOI: 10.1016/j.jmb.2014.09.021] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 09/18/2014] [Accepted: 09/25/2014] [Indexed: 11/29/2022]
Abstract
In many animal cells, stimulation of cell surface receptors coupled to G proteins or tyrosine kinases mobilizes Ca(2+) influx through store-operated Ca(2+)-release-activated Ca(2+) (CRAC) channels. The ensuing Ca(2+) entry regulates a wide variety of effector cell responses including transcription, motility, and proliferation. The physiological importance of CRAC channels for human health is underscored by studies indicating that mutations in CRAC channel genes produce a spectrum of devastating diseases including chronic inflammation, muscle weakness, and a severe combined immunodeficiency syndrome. Moreover, from a basic science perspective, CRAC channels exhibit a unique biophysical fingerprint characterized by exquisite Ca(2+) selectivity, store-operated gating, and distinct pore properties and therefore serve as fascinating model ion channels for understanding the biophysical mechanisms of Ca(2+) selectivity and channel opening. Studies in the last two decades have revealed the cellular and molecular choreography of the CRAC channel activation process, and it is now established that opening of CRAC channels is governed through direct interactions between the pore-forming Orai proteins and the endoplasmic reticulum Ca(2+) sensors STIM1 and STIM2. In this review, we summarize the functional and structural mechanisms of CRAC channel regulation, focusing on recent advances in our understanding of the conformational and structural dynamics of CRAC channel gating.
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Affiliation(s)
- Ann Hye-Ryong Shim
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Leidamarie Tirado-Lee
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Murali Prakriya
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
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17
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Abstract
SIGNIFICANCE Store-operated Ca2+ entry (SOCE) is a ubiquitous Ca2+ signaling mechanism triggered by Ca2+ depletion of the endoplasmic reticulum (ER) and by a variety of cellular stresses. Reactive oxygen species (ROS) are often concomitantly produced in response to these stresses, however, the relationship between redox signaling and SOCE is not completely understood. Various cardiovascular, neurological, and immune diseases are associated with alterations in both Ca2+ signaling and ROS production, and thus understanding this relationship has therapeutic implications. RECENT ADVANCES Several reactive cysteine modifications in stromal interaction molecule (STIM) and Orai proteins comprising the core SOCE machinery were recently shown to modulate SOCE in a redox-dependent manner. Moreover, STIM1 and Orai1 expression levels may reciprocally regulate and be affected by responses to oxidative stress. ER proteins involved in oxidative protein folding have gained increased recognition as important sources of ROS, and the recent discovery of their accumulation in contact sites between the ER and mitochondria provides a further link between ROS production and intracellular Ca2+ handling. CRITICAL ISSUES AND FUTURE DIRECTIONS Future research should aim to establish the complete set of SOCE controlling molecules, to determine their redox-sensitive residues, and to understand how intracellular Ca2+ stores dynamically respond to different types of stress. Mapping the precise nature and functional consequence of key redox-sensitive components of the pre- and post-translational control of SOCE machinery and of proteins regulating ER calcium content will be pivotal in advancing our understanding of the complex cross-talk between redox and Ca2+ signaling.
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Affiliation(s)
- Paula Nunes
- Department of Cell Physiology and Metabolism, University of Geneva , Geneva, Switzerland
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18
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Imaging intraorganellar Ca2+ at subcellular resolution using CEPIA. Nat Commun 2014; 5:4153. [PMID: 24923787 PMCID: PMC4082642 DOI: 10.1038/ncomms5153] [Citation(s) in RCA: 332] [Impact Index Per Article: 33.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 05/16/2014] [Indexed: 12/19/2022] Open
Abstract
The endoplasmic reticulum (ER) and mitochondria accumulate Ca2+ within their lumens to regulate numerous cell functions. However, determining the dynamics of intraorganellar Ca2+ has proven to be difficult. Here we describe a family of genetically encoded Ca2+ indicators, named calcium-measuring organelle-entrapped protein indicators (CEPIA), which can be utilized for intraorganellar Ca2+ imaging. CEPIA, which emit green, red or blue/green fluorescence, are engineered to bind Ca2+ at intraorganellar Ca2+ concentrations. They can be targeted to different organelles and may be used alongside other fluorescent molecular markers, expanding the range of cell functions that can be simultaneously analysed. The spatiotemporal resolution of CEPIA makes it possible to resolve Ca2+ import into individual mitochondria while simultaneously measuring ER and cytosolic Ca2+. We have used these imaging capabilities to reveal differential Ca2+ handling in individual mitochondria. CEPIA imaging is a useful new tool to further the understanding of organellar functions. The use of intracellular calcium sensors provides important information about the dynamics of calcium signalling in cells. Here Suzuki et al. develop organelle-targeted sensors to simultaneously measure calcium concentrations in ER and mitochondria, and uncover novel insights into calcium flux in mitochondria.
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19
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Reversal of Murine Epidermal Atrophy by Topical Modulation of Calcium Signaling. J Invest Dermatol 2014; 134:1599-1608. [DOI: 10.1038/jid.2013.524] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 11/19/2013] [Accepted: 11/20/2013] [Indexed: 11/08/2022]
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20
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Deak AT, Blass S, Khan MJ, Groschner LN, Waldeck-Weiermair M, Hallström S, Graier WF, Malli R. IP3-mediated STIM1 oligomerization requires intact mitochondrial Ca2+ uptake. J Cell Sci 2014; 127:2944-55. [PMID: 24806964 PMCID: PMC4077590 DOI: 10.1242/jcs.149807] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Mitochondria contribute to cell signaling by controlling store-operated Ca2+ entry (SOCE). SOCE is activated by Ca2+ release from the endoplasmic reticulum (ER), whereupon stromal interacting molecule 1 (STIM1) forms oligomers, redistributes to ER–plasma-membrane junctions and opens plasma membrane Ca2+ channels. The mechanisms by which mitochondria interfere with the complex process of SOCE are insufficiently clarified. In this study, we used an shRNA approach to investigate the direct involvement of mitochondrial Ca2+ buffering in SOCE. We demonstrate that knockdown of either of two proteins that are essential for mitochondrial Ca2+ uptake, the mitochondrial calcium uniporter (MCU) or uncoupling protein 2 (UCP2), results in decelerated STIM1 oligomerization and impaired SOCE following cell stimulation with an inositol-1,4,5-trisphosphate (IP3)-generating agonist. Upon artificially augmented cytosolic Ca2+ buffering or ER Ca2+ depletion by sarcoplasmic or endoplasmic reticulum Ca2+-ATPase (SERCA) inhibitors, STIM1 oligomerization did not rely on intact mitochondrial Ca2+ uptake. However, MCU-dependent mitochondrial sequestration of Ca2+ entering through the SOCE pathway was essential to prevent slow deactivation of SOCE. Our findings show a stimulus-specific contribution of mitochondrial Ca2+ uptake to the SOCE machinery, likely through a role in shaping cytosolic Ca2+ micro-domains.
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Affiliation(s)
- Andras T Deak
- The Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, 8010-Graz, Austria
| | - Sandra Blass
- The Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, 8010-Graz, Austria
| | - Muhammad J Khan
- The Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, 8010-Graz, Austria
| | - Lukas N Groschner
- The Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, 8010-Graz, Austria
| | - Markus Waldeck-Weiermair
- The Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, 8010-Graz, Austria
| | - Seth Hallström
- The Institute of Physiological Chemistry, Center of Physiological Medicine, Medical University of Graz, 8010-Graz, Austria
| | - Wolfgang F Graier
- The Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, 8010-Graz, Austria
| | - Roland Malli
- The Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, 8010-Graz, Austria
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Maiellaro I, Lefkimmiatis K, Moyer MP, Curci S, Hofer AM. Termination and activation of store-operated cyclic AMP production. J Cell Mol Med 2014; 16:2715-25. [PMID: 22681560 PMCID: PMC3470754 DOI: 10.1111/j.1582-4934.2012.01592.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Diverse pathophysiological processes (e.g. obesity, lifespan determination, addiction and male fertility) have been linked to the expression of specific isoforms of the adenylyl cyclases (AC1-AC10), the enzymes that generate cyclic AMP (cAMP). Our laboratory recently discovered a new mode of cAMP production, prominent in certain cell types, that is stimulated by any manoeuvre causing reduction of free [Ca2+] within the lumen of the endoplasmic reticulum (ER) calcium store. Activation of this ‘store-operated’ pathway requires the ER Ca2+ sensor, STIM1, but the identity of the enzymes responsible for cAMP production and how this process is regulated is unknown. Here, we used sensitive FRET-based sensors for cAMP in single cells combined with silencing and overexpression approaches to show that store-operated cAMP production occurred preferentially via the isoform AC3 in NCM460 colonic epithelial cells. Ca2+ entry via the plasma membrane Ca2+ channel, Orai1, suppressed cAMP production, independent of store refilling. These findings are an important first step towards defining the functional significance and to identify the protein composition of this novel Ca2+/cAMP crosstalk system.
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Affiliation(s)
- Isabella Maiellaro
- VA Boston Healthcare System, Department of Surgery, Brigham and Women's Hospital, Harvard Medical School, West Roxbury, MA 02132, USA
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22
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Cockcroft S, Garner K. Potential role for phosphatidylinositol transfer protein (PITP) family in lipid transfer during phospholipase C signalling. Adv Biol Regul 2013; 53:280-291. [PMID: 23916246 DOI: 10.1016/j.jbior.2013.07.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 07/11/2013] [Accepted: 07/12/2013] [Indexed: 06/02/2023]
Abstract
The hallmark of mammalian phosphatidylinositol transfer proteins (PITPs) is to transfer phosphatidylinositol between membrane compartments. In the mammalian genome, there are three genes that code for soluble PITP proteins, PITPα, PITPβ and RdgBβ and two genes that code for membrane-associated multi-domain proteins (RdgBαI and II) containing a PITP domain. PITPα and PITPβ constitute Class I PITPs whilst the RdgB proteins constitute Class II proteins based on sequence analysis. The PITP domain of both Class I and II can sequester one molecule of phosphatidylinositol (PI) in its hydrophobic cavity. Therefore, in principle, PITPs are therefore ideally poised to couple phosphatidylinositol delivery to the PI kinases for substrate provision for phospholipases C during cell activation. Since phosphatidylinositol (4,5)bisphosphate plays critical roles in cells, particularly at the plasma membrane, where it is a substrate for both phospholipase C and phosphoinositide-3-kinases as well as required as an intact lipid to regulate ion channels and the actin cytoskeleton, homeostatic mechanisms to maintain phosphatidylinositol(4,5)bisphosphate levels are vital. To maintain phosphatidylinositol levels, phospholipase C activation inevitably leads to the resynthesis of PI at the endoplasmic reticulum where the enzymes are located. Phosphatidic acid generated at the plasma membrane during phospholipase C activation needs to move to the ER for conversion to PI and here we provide evidence that Class II PITPs are also able to bind and transport phosphatidic acid. Thus RdgB proteins could couple PA and PI transport bidirectionally during phospholipase C signalling.
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Affiliation(s)
- Shamshad Cockcroft
- Dept. of Neuroscience, Physiology and Pharmacology, Division of Biosciences, University College London, London WC1E 6JJ, UK.
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23
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Croisier H, Tan X, Perez-Zoghbi JF, Sanderson MJ, Sneyd J, Brook BS. Activation of store-operated calcium entry in airway smooth muscle cells: insight from a mathematical model. PLoS One 2013; 8:e69598. [PMID: 23936056 PMCID: PMC3723852 DOI: 10.1371/journal.pone.0069598] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 06/10/2013] [Indexed: 11/30/2022] Open
Abstract
Intracellular dynamics of airway smooth muscle cells (ASMC) mediate ASMC contraction and proliferation, and thus play a key role in airway hyper-responsiveness (AHR) and remodelling in asthma. We evaluate the importance of store-operated entry (SOCE) in these dynamics by constructing a mathematical model of ASMC signaling based on experimental data from lung slices. The model confirms that SOCE is elicited upon sufficient depletion of the sarcoplasmic reticulum (SR), while receptor-operated entry (ROCE) is inhibited in such conditions. It also shows that SOCE can sustain agonist-induced oscillations in the absence of other influx. SOCE up-regulation may thus contribute to AHR by increasing the oscillation frequency that in turn regulates ASMC contraction. The model also provides an explanation for the failure of the SERCA pump blocker CPA to clamp the cytosolic of ASMC in lung slices, by showing that CPA is unable to maintain the SR empty of . This prediction is confirmed by experimental data from mouse lung slices, and strongly suggests that CPA only partially inhibits SERCA in ASMC.
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Affiliation(s)
- Huguette Croisier
- School of Mathematical Sciences, University of Nottingham, Nottingham, United Kingdom
- * E-mail:
| | - Xiahui Tan
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachussetts, United States of America
| | - Jose F. Perez-Zoghbi
- Department of Cell Physiology and Molecular Biophysics, Texas Tech University Health Sciences Center, Lubbock, Texas, United States of America
| | - Michael J. Sanderson
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachussetts, United States of America
| | - James Sneyd
- Department of Mathematics, University of Auckland, Auckland, New Zealand
| | - Bindi S. Brook
- School of Mathematical Sciences, University of Nottingham, Nottingham, United Kingdom
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Orai-STIM-mediated Ca2+ release from secretory granules revealed by a targeted Ca2+ and pH probe. Proc Natl Acad Sci U S A 2012. [PMID: 23184982 DOI: 10.1073/pnas.1218247109] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Secretory granules (SGs) sequester significant calcium. Understanding roles for this calcium and potential mechanisms of release is hampered by the difficulty of measuring SG calcium directly in living cells. We adapted the Förster resonance energy transfer-based D1-endoplasmic reticulum (ER) probe to develop a unique probe (D1-SG) to measure calcium and pH in secretory granules. It significantly localizes to SGs and reports resting free Ca(2+) of 69 ± 15 μM and a pH of 5.8. Application of extracellular ATP to activate P2Y receptors resulted in a slow monotonic decrease in SG Ca(2+) temporally correlated with the occurrence of store-operated calcium entry (SOCE). Further investigation revealed a unique receptor-mediated mechanism of calcium release from SGs that involves SG store-operated Orai channels activated by their regulator stromal interaction molecule 1 (STIM1) on the ER. SG Ca(2+) release is completely antagonized by a SOCE antagonist, by switching to Ca(2+)-free medium, and by overexpression of a dominant-negative Orai1(E106A). Overexpression of the CRAC activation domain (CAD) of STIM1 resulted in a decrease of resting SG Ca(2+) by ∼75% and completely abolished the ATP-mediated release of Ca(2+) from SGs. Overexpression of a dominant-negative CAD construct(CAD-A376K) induced no significant changes in SG Ca(2+). Colocalization analysis suggests that, like the plasma membrane, SG membranes also possess Orai1 channels and that during SG Ca(2+) release, colocalization between SGs and STIM1 increases. We propose Orai channel opening on SG membranes as a potential mode of calcium release from SGs that may serve to raise local cytoplasmic calcium concentrations and aid in refilling intracellular calcium stores of the ER and exocytosis.
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25
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Soboloff J, Rothberg BS, Madesh M, Gill DL. STIM proteins: dynamic calcium signal transducers. Nat Rev Mol Cell Biol 2012; 13:549-65. [PMID: 22914293 DOI: 10.1038/nrm3414] [Citation(s) in RCA: 518] [Impact Index Per Article: 43.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Stromal interaction molecule (STIM) proteins function in cells as dynamic coordinators of cellular calcium (Ca(2+)) signals. Spanning the endoplasmic reticulum (ER) membrane, they sense tiny changes in the levels of Ca(2+) stored within the ER lumen. As ER Ca(2+) is released to generate primary Ca(2+) signals, STIM proteins undergo an intricate activation reaction and rapidly translocate into junctions formed between the ER and the plasma membrane. There, STIM proteins tether and activate the highly Ca(2+)-selective Orai channels to mediate finely controlled Ca(2+) signals and to homeostatically balance cellular Ca(2+). Details are emerging on the remarkable organization within these STIM-induced junctional microdomains and the identification of new regulators and alternative target proteins for STIM.
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Affiliation(s)
- Jonathan Soboloff
- Department of Biochemistry, Temple University School of Medicine, 3400 North Broad Street, Philadelphia, Pennsylvania 19140, USA
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Shaw PJ, Qu B, Hoth M, Feske S. Molecular regulation of CRAC channels and their role in lymphocyte function. Cell Mol Life Sci 2012; 70:2637-56. [PMID: 23052215 DOI: 10.1007/s00018-012-1175-2] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Revised: 09/16/2012] [Accepted: 09/17/2012] [Indexed: 12/12/2022]
Abstract
Calcium (Ca(2+)) influx is required for the activation and function of all cells in the immune system. It is mediated mainly by store-operated Ca(2+) entry (SOCE) through Ca(2+) release-activated Ca(2+) (CRAC) channels located in the plasma membrane. CRAC channels are composed of ORAI proteins that form the channel pore and are activated by stromal interaction molecules (STIM) 1 and 2. Located in the membrane of the endoplasmic reticulum, STIM1 and STIM2 have the dual function of sensing the intraluminal Ca(2+) concentration in the ER and to activate CRAC channels. A decrease in the ER's Ca(2+) concentration induces STIM multimerization and translocation into puncta close to the plasma membrane where they bind to and activate ORAI channels. Since the identification of ORAI and STIM genes as the principal mediators of CRAC channel function, substantial advances have been achieved in understanding the molecular regulation and physiological role of CRAC channels in cells of the immune system and other organs. In this review, we discuss the mechanisms that regulate CRAC channel function and SOCE, the role of recently identified proteins and mechanisms that modulate the activation of ORAI/STIM proteins and the consequences of CRAC channel dysregulation for lymphocyte function and immunity.
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Affiliation(s)
- Patrick J Shaw
- Department of Pathology, New York University Medical Center, 550 First Avenue, SRB 316, New York, NY 10016, USA
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Nunes P, Cornut D, Bochet V, Hasler U, Oh-Hora M, Waldburger JM, Demaurex N. STIM1 juxtaposes ER to phagosomes, generating Ca²⁺ hotspots that boost phagocytosis. Curr Biol 2012; 22:1990-7. [PMID: 23041196 DOI: 10.1016/j.cub.2012.08.049] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 08/14/2012] [Accepted: 08/23/2012] [Indexed: 11/28/2022]
Abstract
BACKGROUND Endoplasmic reticulum (ER) membranes are recruited to phagosomes, but the mechanism and functional significance of this ER recruitment is not known. Here, we show that the ER Ca(2+) sensor stromal interaction molecule 1 (STIM1) sustains high-efficiency phagocytosis by recruiting thin ER cisternae that interact productively but do not fuse with phagosomes. RESULTS Endogenous STIM1 was recruited to phagosomes upon ER Ca(2+) depletion in mouse neutrophils, and exogenous YFP-STIM1 puncta coincided with localized Ca(2+) elevations around phagosomes in fibroblasts expressing phagocytic receptors. STIM1 ablation decreased phagocytosis, ER-phagosome contacts, and periphagosomal Ca(2+) elevations in both neutrophils and fibroblasts, whereas STIM1 re-expression in Stim1(-/-) fibroblasts rescued these defects, promoted the formation and elongation of tight ER-phagosome contacts upon ER Ca(2+) depletion and increased the shedding of periphagosomal actin rings. Re-expression of a signaling-deficient STIM1 mutant unable to open Ca(2+) channels recruited ER cisternae to the vicinity of phagosomes but failed to rescue phagocytosis, actin shedding, and periphagosomal Ca(2+) elevations. The periphagosomal Ca(2+) hotspots were decreased by extracellular Ca(2+) chelation and by Ca(2+) channels inhibitors, revealing that the Ca(2+) ions originate at least in part from phagosomes. CONCLUSIONS Our findings indicate that STIM1 recruits ER cisternae near phagosomes for signaling purposes and that the opening of phagosomal Ca(2+) channels generates localized Ca(2+) elevations that promote high-efficiency phagocytosis.
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Affiliation(s)
- Paula Nunes
- Department of Cell Physiology and Metabolism, University of Geneva, 1211 Geneva 4, Switzerland
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Muik M, Schindl R, Fahrner M, Romanin C. Ca(2+) release-activated Ca(2+) (CRAC) current, structure, and function. Cell Mol Life Sci 2012; 69:4163-76. [PMID: 22802126 PMCID: PMC3505497 DOI: 10.1007/s00018-012-1072-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2012] [Revised: 06/07/2012] [Accepted: 06/21/2012] [Indexed: 10/28/2022]
Abstract
Store-operated Ca(2+) entry describes the phenomenon that connects a depletion of internal Ca(2+) stores to an activation of plasma membrane-located Ca(2+) selective ion channels. Tremendous progress towards the underlying molecular mechanism came with the discovery of the two respective limiting components, STIM and Orai. STIM1 represents the ER-located Ca(2+) sensor and transmits the signal of store depletion to the plasma membrane. Here it couples to and activates Orai, the highly Ca(2+)-selective pore-forming subunit of Ca(2+) release-activated Ca(2+) channels. In this review, we focus on the molecular steps that these two proteins undergo from store-depletion to their coupling, the activation, and regulation of Ca(2+) currents.
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Affiliation(s)
- Martin Muik
- Institute of Biophysics, University of Linz, Gruberstrasse 40, 4020 Linz, Austria
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Willer EA, Malli R, Bondarenko AI, Zahler S, Vollmar AM, Graier WF, Fürst R. The vascular barrier-protecting hawthorn extract WS® 1442 raises endothelial calcium levels by inhibition of SERCA and activation of the IP3 pathway. J Mol Cell Cardiol 2012; 53:567-77. [PMID: 22814436 DOI: 10.1016/j.yjmcc.2012.07.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 07/06/2012] [Indexed: 10/28/2022]
Abstract
WS® 1442 has been proven as an effective and safe therapeutical to treat mild forms of congestive heart failure. Beyond this action, we have recently shown that WS® 1442 protects against thrombin-induced vascular barrier dysfunction and the subsequent edema formation by affecting endothelial calcium signaling. The aim of the study was to analyze the influence of WS® 1442 on intracellular calcium concentrations [Ca(2+)](i) in the human endothelium and to investigate the underlying mechanisms. Using ratiometric calcium measurements and a FRET sensor, we found that WS® 1442 concentration-dependently increased basal [Ca(2+)](i) by depletion of the endoplasmic reticulum (ER) and inhibited a subsequent histamine-triggered rise of [Ca(2+)](i). Interestingly, the augmented [Ca(2+)](i) did neither trigger an activation of the contractile machinery nor led to a barrier breakdown (macromolecular permeability). It also did not impair endothelial cell viability. As assessed by patch clamp recordings, WS® 1442 did only slightly affect endothelial Na(+)/K(+)-ATPase, but increased [Ca(2+)](i) by inhibiting the sarcoplasmic/endoplasmic reticulum Ca(2+) ATPase (SERCA) and by activating the inositol 1,4,5-trisphosphate (IP(3)) pathway. Most importantly, WS® 1442 did not induce store-operated calcium entry (SOCE), but even irreversibly prevented histamine-induced SOCE. Taken together, WS® 1442 prevented the deleterious hyperpermeability-associated rise of [Ca(2+)](i) by a preceding, non-toxic release of Ca(2+) from the ER. WS® 1442 interfered with SERCA and the IP(3) pathway without inducing SOCE. The elucidation of this intriguing mechanism helps to understand the complex pharmacology of the cardiovascular drug WS® 1442.
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Affiliation(s)
- Elisabeth A Willer
- Department of Pharmacy, Centre for Drug Research, Pharmaceutical Biology, University of Munich, Butenandtstr. 5-13, 81377 Munich, Germany
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SARAF Inactivates the Store Operated Calcium Entry Machinery to Prevent Excess Calcium Refilling. Cell 2012; 149:425-38. [DOI: 10.1016/j.cell.2012.01.055] [Citation(s) in RCA: 200] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Revised: 11/24/2011] [Accepted: 01/26/2012] [Indexed: 11/17/2022]
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Tian G, Tepikin AV, Tengholm A, Gylfe E. cAMP induces stromal interaction molecule 1 (STIM1) puncta but neither Orai1 protein clustering nor store-operated Ca2+ entry (SOCE) in islet cells. J Biol Chem 2012; 287:9862-9872. [PMID: 22298778 DOI: 10.1074/jbc.m111.292854] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The events leading to the activation of store-operated Ca(2+) entry (SOCE) involve Ca(2+) depletion of the endoplasmic reticulum (ER) resulting in translocation of the transmembrane Ca(2+) sensor protein, stromal interaction molecule 1 (STIM1), to the junctions between ER and the plasma membrane where it binds to the Ca(2+) channel protein Orai1 to activate Ca(2+) influx. Using confocal and total internal reflection fluorescence microscopy, we studied redistribution kinetics of fluorescence-tagged STIM1 and Orai1 as well as SOCE in insulin-releasing β-cells and glucagon-secreting α-cells within intact mouse and human pancreatic islets. ER Ca(2+) depletion triggered accumulation of STIM1 puncta in the subplasmalemmal ER where they co-clustered with Orai1 in the plasma membrane and activated SOCE. Glucose, which promotes Ca(2+) store filling and inhibits SOCE, stimulated retranslocation of STIM1 to the bulk ER. This effect was evident at much lower glucose concentrations in α- than in β-cells consistent with involvement of SOCE in the regulation of glucagon secretion. Epinephrine stimulated subplasmalemmal translocation of STIM1 in α-cells and retranslocation in β-cells involving raising and lowering of cAMP, respectively. The cAMP effect was mediated both by protein kinase A and exchange protein directly activated by cAMP. However, the cAMP-induced STIM1 puncta did not co-cluster with Orai1, and there was no activation of SOCE. STIM1 translocation can consequently occur independently of Orai1 clustering and SOCE.
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Affiliation(s)
- Geng Tian
- Department of Medical Cell Biology, Uppsala University, BMC Box 571, SE-751 23 Uppsala, Sweden and
| | - Alexei V Tepikin
- Physiological Laboratory, Department of Cellular and Molecular Physiology, University of Liverpool, Liverpool L69 3BX, United Kingdom
| | - Anders Tengholm
- Department of Medical Cell Biology, Uppsala University, BMC Box 571, SE-751 23 Uppsala, Sweden and
| | - Erik Gylfe
- Department of Medical Cell Biology, Uppsala University, BMC Box 571, SE-751 23 Uppsala, Sweden and.
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