151
|
Palty R, Fu Z, Isacoff EY. Sequential Steps of CRAC Channel Activation. Cell Rep 2018; 19:1929-1939. [PMID: 28564609 DOI: 10.1016/j.celrep.2017.05.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 03/27/2017] [Accepted: 05/05/2017] [Indexed: 10/19/2022] Open
Abstract
Interaction between the endoplasmic reticulum protein STIM1 and the plasma membrane channel ORAI1 generates calcium signals that are central for diverse cellular functions. How STIM1 binds and activates ORAI1 remains poorly understood. Using electrophysiological, optical, and biochemical techniques, we examined the effects of mutations in the STIM1-ORAI1 activating region (SOAR) of STIM1. We find that SOAR mutants that are deficient in binding to resting ORAI1 channels are able to bind to and boost activation of partially activated ORAI1 channels. We further show that the STIM1 binding regions on ORAI1 undergo structural rearrangement during channel activation. The results suggest that activation of ORAI1 by SOAR occurs in multiple steps. In the first step, SOAR binds to ORAI1, partially activates the channel, and induces a rearrangement in the SOAR-binding site of ORAI1. That rearrangement of ORAI1 then permits sequential steps of SOAR binding, via distinct molecular interactions, to fully activate the channel.
Collapse
Affiliation(s)
- Raz Palty
- Department of Biochemistry, Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa 31096, Israel.
| | - Zhu Fu
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Ehud Y Isacoff
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA; Bioscience Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
| |
Collapse
|
152
|
Lopez JJ, Albarrán L, Jardín I, Sanchez-Collado J, Redondo PC, Bermejo N, Bobe R, Smani T, Rosado JA. Filamin A Modulates Store-Operated Ca2+Entry by Regulating STIM1 (Stromal Interaction Molecule 1)–Orai1 Association in Human Platelets. Arterioscler Thromb Vasc Biol 2018; 38:386-397. [DOI: 10.1161/atvbaha.117.310139] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2017] [Accepted: 12/13/2017] [Indexed: 12/23/2022]
Affiliation(s)
- Jose J. Lopez
- From the Department of Physiology, University of Extremadura, Cáceres, Spain (J.J.L., L.A., I.J., J.S.-C., P.C.R., J.A.R.); Department of Hematology, Hospital San Pedro de Alcantara, Cáceres, Spain (N.B.); INSERM Unité Mixte de Recherche-Santé 1176, Université Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France (R.B.); and Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Spain (T.S.)
| | - Letizia Albarrán
- From the Department of Physiology, University of Extremadura, Cáceres, Spain (J.J.L., L.A., I.J., J.S.-C., P.C.R., J.A.R.); Department of Hematology, Hospital San Pedro de Alcantara, Cáceres, Spain (N.B.); INSERM Unité Mixte de Recherche-Santé 1176, Université Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France (R.B.); and Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Spain (T.S.)
| | - Isaac Jardín
- From the Department of Physiology, University of Extremadura, Cáceres, Spain (J.J.L., L.A., I.J., J.S.-C., P.C.R., J.A.R.); Department of Hematology, Hospital San Pedro de Alcantara, Cáceres, Spain (N.B.); INSERM Unité Mixte de Recherche-Santé 1176, Université Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France (R.B.); and Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Spain (T.S.)
| | - Jose Sanchez-Collado
- From the Department of Physiology, University of Extremadura, Cáceres, Spain (J.J.L., L.A., I.J., J.S.-C., P.C.R., J.A.R.); Department of Hematology, Hospital San Pedro de Alcantara, Cáceres, Spain (N.B.); INSERM Unité Mixte de Recherche-Santé 1176, Université Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France (R.B.); and Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Spain (T.S.)
| | - Pedro C. Redondo
- From the Department of Physiology, University of Extremadura, Cáceres, Spain (J.J.L., L.A., I.J., J.S.-C., P.C.R., J.A.R.); Department of Hematology, Hospital San Pedro de Alcantara, Cáceres, Spain (N.B.); INSERM Unité Mixte de Recherche-Santé 1176, Université Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France (R.B.); and Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Spain (T.S.)
| | - Nuria Bermejo
- From the Department of Physiology, University of Extremadura, Cáceres, Spain (J.J.L., L.A., I.J., J.S.-C., P.C.R., J.A.R.); Department of Hematology, Hospital San Pedro de Alcantara, Cáceres, Spain (N.B.); INSERM Unité Mixte de Recherche-Santé 1176, Université Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France (R.B.); and Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Spain (T.S.)
| | - Regis Bobe
- From the Department of Physiology, University of Extremadura, Cáceres, Spain (J.J.L., L.A., I.J., J.S.-C., P.C.R., J.A.R.); Department of Hematology, Hospital San Pedro de Alcantara, Cáceres, Spain (N.B.); INSERM Unité Mixte de Recherche-Santé 1176, Université Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France (R.B.); and Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Spain (T.S.)
| | - Tarik Smani
- From the Department of Physiology, University of Extremadura, Cáceres, Spain (J.J.L., L.A., I.J., J.S.-C., P.C.R., J.A.R.); Department of Hematology, Hospital San Pedro de Alcantara, Cáceres, Spain (N.B.); INSERM Unité Mixte de Recherche-Santé 1176, Université Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France (R.B.); and Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Spain (T.S.)
| | - Juan A. Rosado
- From the Department of Physiology, University of Extremadura, Cáceres, Spain (J.J.L., L.A., I.J., J.S.-C., P.C.R., J.A.R.); Department of Hematology, Hospital San Pedro de Alcantara, Cáceres, Spain (N.B.); INSERM Unité Mixte de Recherche-Santé 1176, Université Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France (R.B.); and Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Spain (T.S.)
| |
Collapse
|
153
|
Derler I, Butorac C, Krizova A, Stadlbauer M, Muik M, Fahrner M, Frischauf I, Romanin C. Authentic CRAC channel activity requires STIM1 and the conserved portion of the Orai N terminus. J Biol Chem 2018; 293:1259-1270. [PMID: 29237734 PMCID: PMC5787803 DOI: 10.1074/jbc.m117.812206] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 11/23/2017] [Indexed: 11/06/2022] Open
Abstract
Calcium (Ca2+) is an essential second messenger required for diverse signaling processes in immune cells. Ca2+ release-activated Ca2+ (CRAC) channels represent one main Ca2+ entry pathway into the cell. They are fully reconstituted via two proteins, the stromal interaction molecule 1 (STIM1), a Ca2+ sensor in the endoplasmic reticulum, and the Ca2+ ion channel Orai in the plasma membrane. After Ca2+ store depletion, STIM1 and Orai couple to each other, allowing Ca2+ influx. CRAC-/STIM1-mediated Orai channel currents display characteristic hallmarks such as high Ca2+ selectivity, an increase in current density when switching from a Ca2+-containing solution to a divalent-free Na+ one, and fast Ca2+-dependent inactivation. Here, we discovered several constitutively active Orai1 and Orai3 mutants, containing substitutions in the TM3 and/or TM4 regions, all of which displayed a loss of the typical CRAC channel hallmarks. Restoring authentic CRAC channel activity required both the presence of STIM1 and the conserved Orai N-terminal portion. Similarly, these structural requisites were found in store-operated Orai channels. Key molecular determinants within the Orai N terminus that together with STIM1 maintained the typical CRAC channel hallmarks were distinct from those that controlled store-dependent Orai activation. In conclusion, the conserved portion of the Orai N terminus is essential for STIM1, as it fine-tunes the open Orai channel gating, thereby establishing authentic CRAC channel activity.
Collapse
Affiliation(s)
- Isabella Derler
- From the Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Carmen Butorac
- From the Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Adéla Krizova
- From the Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Michael Stadlbauer
- From the Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Martin Muik
- From the Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Marc Fahrner
- From the Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Irene Frischauf
- From the Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Christoph Romanin
- From the Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020 Linz, Austria
| |
Collapse
|
154
|
Dubois C, Prevarskaya N. Western Blotting and Co-immunoprecipitation of Endogenous STIM/ORAI and Protein Partners. Methods Mol Biol 2018; 1843:107-113. [PMID: 30203281 DOI: 10.1007/978-1-4939-8704-7_9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The characterization of protein-protein interactions through methods such as co-immunoprecipitation, followed by Western blot analysis, is a crucial step in the understanding of protein functions and the biology of the cell. Since the discovery of ORAI and STIM proteins as component of store-operated channel (SOC), overexpressing systems have been used to demonstrate how ORAI and STIM can associate with physiological and pathological conditions. Here we describe a protocol allowing endogenous studies.
Collapse
Affiliation(s)
- Charlotte Dubois
- INSERM U1003, Laboratoire d'Excellence, Canaux Ioniques d'Intérêt Thérapeutique, Équipe Labellisée Par la Ligue Nationale Contre le Cancer, SIRIC ONCOLille, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq, France
| | - Natalia Prevarskaya
- INSERM U1003, Laboratoire d'Excellence, Canaux Ioniques d'Intérêt Thérapeutique, Équipe Labellisée Par la Ligue Nationale Contre le Cancer, SIRIC ONCOLille, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq, France.
| |
Collapse
|
155
|
Oh MR, Lee KJ, Huang M, Kim JO, Kim DH, Cho CH, Lee EH. STIM2 regulates both intracellular Ca 2+ distribution and Ca 2+ movement in skeletal myotubes. Sci Rep 2017; 7:17936. [PMID: 29263348 PMCID: PMC5738411 DOI: 10.1038/s41598-017-18256-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 12/08/2017] [Indexed: 01/09/2023] Open
Abstract
Stromal interaction molecule 1 (STIM1) along with Orai1 mediates extracellular Ca2+ entry into the cytosol through a store-operated Ca2+ entry (SOCE) mechanism in various tissues including skeletal muscle. However, the role(s) of STIM2, a homolog of STIM1, in skeletal muscle has not been well addressed. The present study, first, was focused on searching for STIM2-binding proteins from among proteins mediating skeletal muscle functions. This study used a binding assay, quadrupole time-of-flight mass spectrometry, and co-immunoprecipitation assay with bona-fide STIM2- and SERCA1a-expressing rabbit skeletal muscle. The region for amino acids from 453 to 729 of STIM2 binds to sarcoplasmic/endoplasmic reticulum Ca2+-ATPase 1a (SERCA1a). Next, oxalate-supported 45Ca2+-uptake experiments and various single-myotube Ca2+ imaging experiments using STIM2-knockdown mouse primary skeletal myotubes have suggested that STIM2 attenuates SERCA1a activity during skeletal muscle contraction, which contributes to the intracellular Ca2+ distribution between the cytosol and the SR at rest. In addition, STIM2 regulates Ca2+ movement through RyR1 during skeletal muscle contraction as well as SOCE. Therefore, via regulation of SERCA1a activity, STIM2 regulates both intracellular Ca2+ distribution and Ca2+ movement in skeletal muscle, which makes it both similar to, yet different from, STIM1.
Collapse
Affiliation(s)
- Mi Ri Oh
- Department of Physiology, College of Medicine, The Catholic University of Korea, Seoul, 06591, Republic of Korea
| | - Keon Jin Lee
- Department of Physiology, College of Medicine, The Catholic University of Korea, Seoul, 06591, Republic of Korea
| | - Mei Huang
- Department of Physiology, College of Medicine, The Catholic University of Korea, Seoul, 06591, Republic of Korea
| | - Jin Ock Kim
- School of Life Sciences, GIST, Gwangju, 61005, Republic of Korea
| | - Do Han Kim
- School of Life Sciences, GIST, Gwangju, 61005, Republic of Korea
| | - Chung-Hyun Cho
- Department of Pharmacology, College of Medicine, Seoul National University, Seoul, 08826, Republic of Korea
| | - Eun Hui Lee
- Department of Physiology, College of Medicine, The Catholic University of Korea, Seoul, 06591, Republic of Korea.
| |
Collapse
|
156
|
Molino D, Nascimbeni AC, Giordano F, Codogno P, Morel E. ER-driven membrane contact sites: Evolutionary conserved machineries for stress response and autophagy regulation? Commun Integr Biol 2017; 10:e1401699. [PMID: 29259731 PMCID: PMC5731517 DOI: 10.1080/19420889.2017.1401699] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 10/20/2017] [Accepted: 10/31/2017] [Indexed: 10/26/2022] Open
Abstract
Endoplasmic Reticulum (ER), spreading in the whole cell cytoplasm, is a central player in eukaryotic cell homeostasis, from plants to mammals. Beside crucial functions, such as membrane lipids and proteins synthesis and outward transport, the ER is able to connect to virtually every endomembrane compartment by specific tethering molecular machineries, which enables the establishment of membrane-membrane contact sites. ER-mitochondria contact sites have been shown to be involved in autophagosome biogenesis, the main organelle of the autophagy degradation pathway. More recently we demonstrated that also ER-plasma membrane contact sites are sites for autophagosomes assembly, suggesting that more generally ER-organelles contacts are involved in autophagy and organelle biogenesis. Here we aim to discuss the functioning of ER-driven contact sites in mammals and plants and more in particular emphasize on their recently highlighted function in autophagy to finally conclude on some key questions that may be useful for further research in the field.
Collapse
Affiliation(s)
- Diana Molino
- Institut Necker-Enfants Malades (INEM), INSERM U1151-CNRS UMR.,Université Paris Descartes-Sorbonne Paris Cité, Paris, France
| | - Anna Chiara Nascimbeni
- Institut Necker-Enfants Malades (INEM), INSERM U1151-CNRS UMR.,Université Paris Descartes-Sorbonne Paris Cité, Paris, France
| | - Francesca Giordano
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Patrice Codogno
- Institut Necker-Enfants Malades (INEM), INSERM U1151-CNRS UMR.,Université Paris Descartes-Sorbonne Paris Cité, Paris, France
| | - Etienne Morel
- Institut Necker-Enfants Malades (INEM), INSERM U1151-CNRS UMR.,Université Paris Descartes-Sorbonne Paris Cité, Paris, France
| |
Collapse
|
157
|
Zhu J, Feng Q, Stathopulos PB. The STIM-Orai Pathway: STIM-Orai Structures: Isolated and in Complex. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 993:15-38. [PMID: 28900907 DOI: 10.1007/978-3-319-57732-6_2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Abstract
Considerable progress has been made elucidating the molecular mechanisms of calcium (Ca2+) sensing by stromal interaction molecules (STIMs) and the basis for Orai channel activity. This chapter focuses on the available high-resolution structural details of STIM and Orai proteins with respect to the regulation of store-operated Ca2+ entry (SOCE). Solution structures of the Ca2+-sensing domains of STIM1 and STIM2 are reviewed in detail, crystal structures of cytosolic coiled-coil STIM fragments are discussed, and an overview of the closed Drosophila melanogaster Orai hexameric structure is provided. Additionally, we highlight structures of human Orai1 N-terminal and C-terminal domains in complex with calmodulin and human STIM1, respectively. Ultimately, the accessible structural data are discussed in terms of potential mechanisms of action and cohesiveness with functional observations.
Collapse
Affiliation(s)
- Jinhui Zhu
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Qingping Feng
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Peter B Stathopulos
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1.
| |
Collapse
|
158
|
Traxler L, Rathner P, Fahrner M, Stadlbauer M, Faschinger F, Charnavets T, Müller N, Romanin C, Hinterdorfer P, Gruber HJ. Multiple Evidenz für einen ungewöhnlichen Wechselwirkungsmodus zwischen Calmodulin und Orai-Proteinen. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201708667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Lukas Traxler
- Institut für Biophysik; Johannes Kepler Universität; Gruberstrasse 40 4020 Linz Österreich
| | - Petr Rathner
- Institut für Organische Chemie; Johannes Kepler Universität; Altenberger Strasse 69 4020 Linz Österreich
| | - Marc Fahrner
- Institut für Biophysik; Johannes Kepler Universität; Gruberstrasse 40 4020 Linz Österreich
| | - Michael Stadlbauer
- Institut für Biophysik; Johannes Kepler Universität; Gruberstrasse 40 4020 Linz Österreich
| | - Felix Faschinger
- Institut für Biophysik; Johannes Kepler Universität; Gruberstrasse 40 4020 Linz Österreich
| | - Tatsiana Charnavets
- CF Centre of Molecular Structure, BIOCEV; Průmyslová 595 252 50 Vestec Tschechische Republik
| | - Norbert Müller
- Institut für Organische Chemie; Johannes Kepler Universität; Altenberger Strasse 69 4020 Linz Österreich
- Faculty of Science; University of South Bohemia; Branišovská 31 370 05 České Budějovice Tschechische Republik
| | - Christoph Romanin
- Institut für Biophysik; Johannes Kepler Universität; Gruberstrasse 40 4020 Linz Österreich
| | - Peter Hinterdorfer
- Institut für Biophysik; Johannes Kepler Universität; Gruberstrasse 40 4020 Linz Österreich
| | - Hermann J. Gruber
- Institut für Biophysik; Johannes Kepler Universität; Gruberstrasse 40 4020 Linz Österreich
| |
Collapse
|
159
|
Traxler L, Rathner P, Fahrner M, Stadlbauer M, Faschinger F, Charnavets T, Müller N, Romanin C, Hinterdorfer P, Gruber HJ. Detailed Evidence for an Unparalleled Interaction Mode between Calmodulin and Orai Proteins. Angew Chem Int Ed Engl 2017; 56:15755-15759. [PMID: 29024298 DOI: 10.1002/anie.201708667] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Indexed: 12/12/2022]
Abstract
Calmodulin (CaM) binds most of its targets by wrapping around an amphipathic α-helix. The N-terminus of Orai proteins contains a conserved CaM-binding segment but the binding mechanism has been only partially characterized. Here, microscale thermophoresis (MST), surface plasmon resonance (SPR), and atomic force microscopy (AFM) were employed to study the binding equilibria, the kinetics, and the single-molecule interaction forces involved in the binding of CaM to the conserved helical segments of Orai1 and Orai3. The results consistently indicated stepwise binding of two separate target peptides to the two lobes of CaM. An unparalleled high affinity was found when two Orai peptides were dimerized or immobilized at high lateral density, thereby mimicking the close proximity of the N-termini in native Orai oligomers. The analogous experiments with smooth muscle myosin light chain kinase (smMLCK) showed only the expected 1:1 binding, confirming the validity of our methods.
Collapse
Affiliation(s)
- Lukas Traxler
- Institute of Biophysics, Johannes Kepler University, Gruberstrasse 40, 4020, Linz, Austria
| | - Petr Rathner
- Institute of Organic Chemistry, Johannes Kepler University, Altenberger Strasse 69, 4020, Linz, Austria
| | - Marc Fahrner
- Institute of Biophysics, Johannes Kepler University, Gruberstrasse 40, 4020, Linz, Austria
| | - Michael Stadlbauer
- Institute of Biophysics, Johannes Kepler University, Gruberstrasse 40, 4020, Linz, Austria
| | - Felix Faschinger
- Institute of Biophysics, Johannes Kepler University, Gruberstrasse 40, 4020, Linz, Austria
| | - Tatsiana Charnavets
- CF Centre of Molecular Structure, BIOCEV, Průmyslová 595, 252 50, Vestec, Czech Republic
| | - Norbert Müller
- Institute of Organic Chemistry, Johannes Kepler University, Altenberger Strasse 69, 4020, Linz, Austria.,Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Christoph Romanin
- Institute of Biophysics, Johannes Kepler University, Gruberstrasse 40, 4020, Linz, Austria
| | - Peter Hinterdorfer
- Institute of Biophysics, Johannes Kepler University, Gruberstrasse 40, 4020, Linz, Austria
| | - Hermann J Gruber
- Institute of Biophysics, Johannes Kepler University, Gruberstrasse 40, 4020, Linz, Austria
| |
Collapse
|
160
|
Wang J, Xu C, Zheng Q, Yang K, Lai N, Wang T, Tang H, Lu W. Orai1, 2, 3 and STIM1 promote store-operated calcium entry in pulmonary arterial smooth muscle cells. Cell Death Discov 2017; 3:17074. [PMID: 29188077 PMCID: PMC5702854 DOI: 10.1038/cddiscovery.2017.74] [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: 06/21/2017] [Revised: 08/05/2017] [Accepted: 08/24/2017] [Indexed: 12/04/2022] Open
Abstract
Previous studies have demonstrated that besides the classic canonical transient receptor potential channel family, Orai family and stromal interaction molecule 1 (STIM1) might also be involved in the regulation of store-operated calcium channels (SOCCs). An increase in cytosolic free Ca2+ concentration promoted by store-operated Ca2+ entry (SOCE) in pulmonary arterial smooth muscle cells (PASMCs) is a major trigger for pulmonary vasoconstriction and proliferation and migration of PASMCs. In this study, our data revealed the following: (1) in both rat distal pulmonary arteries and PASMCs, chronic hypoxia exposure upregulated the expression of Orai1 and Orai2, without affecting Orai3 and STIM1; (2) either heterozygous knockout of HIF-1α in mice or knockdown of HIF-1α in PASMCs abolished the hypoxic upregulation of Orai2, but not Orai1, suggesting the hypoxic upregulation of Orai2 depends on HIF-1α; and (3) using small interference RNA knockdown strategies, Orai1, 2, 3 and STIM1 were all shown to mediate SOCE in hypoxic PASMCs. Together, these results suggested that the components of SOCCs, including Orai1, 2, 3 and STIM1, may lead to novel therapeutic targets for the treatment of chronic hypoxia-induced pulmonary hypertension.
Collapse
Affiliation(s)
- Jian Wang
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510180, China.,Division of Translational and Regenerative Medicine, Department of Medicine, The University of Arizona, Tucson, AZ 85721-0202, USA
| | - Chuyi Xu
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510180, China
| | - Qiuyu Zheng
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510180, China
| | - Kai Yang
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510180, China
| | - Ning Lai
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510180, China
| | - Tao Wang
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510180, China
| | - Haiyang Tang
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510180, China.,Division of Translational and Regenerative Medicine, Department of Medicine, The University of Arizona, Tucson, AZ 85721-0202, USA
| | - Wenju Lu
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510180, China
| |
Collapse
|
161
|
Hsieh TS, Chen YJ, Chang CL, Lee WR, Liou J. Cortical actin contributes to spatial organization of ER-PM junctions. Mol Biol Cell 2017; 28:3171-3180. [PMID: 28954864 PMCID: PMC5687020 DOI: 10.1091/mbc.e17-06-0377] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 09/18/2017] [Accepted: 09/20/2017] [Indexed: 01/16/2023] Open
Abstract
Endoplasmic reticulum-plasma membrane (ER-PM) junctions mediate crucial activities ranging from Ca2+ signaling to lipid metabolism. Spatial organization of ER-PM junctions may modulate the extent and location of these cellular activities. However, the morphology and distribution of ER-PM junctions are not well characterized. Using photoactivated localization microscopy, we reveal that the contact area of single ER-PM junctions is mainly oblong with the dimensions of ∼120 nm × ∼80 nm in HeLa cells. Using total internal reflection fluorescence microscopy and structure illumination microscopy, we show that cortical actin contributes to spatial distribution and stability of ER-PM junctions. Further functional assays suggest that intact F-actin architecture is required for phosphatidylinositol 4,5-bisphosphate homeostasis mediated by Nir2 at ER-PM junctions. Together, our study provides quantitative information on spatial organization of ER-PM junctions that is in part regulated by F-actin. We envision that functions of ER-PM junctions can be differentially regulated through dynamic actin remodeling during cellular processes.
Collapse
Affiliation(s)
- Ting-Sung Hsieh
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Yu-Ju Chen
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Chi-Lun Chang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Wan-Ru Lee
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Jen Liou
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| |
Collapse
|
162
|
Boncompagni S, Michelucci A, Pietrangelo L, Dirksen RT, Protasi F. Exercise-dependent formation of new junctions that promote STIM1-Orai1 assembly in skeletal muscle. Sci Rep 2017; 7:14286. [PMID: 29079778 PMCID: PMC5660245 DOI: 10.1038/s41598-017-14134-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 10/09/2017] [Indexed: 12/14/2022] Open
Abstract
Store-operated Ca2+ entry (SOCE), a ubiquitous mechanism that allows recovery of Ca2+ ions from the extracellular space, has been proposed to limit fatigue during repetitive skeletal muscle activity. However, the subcellular location for SOCE in muscle fibers has not been unequivocally identified. Here we show that exercise drives a significant remodeling of the sarcotubular system to form previously unidentified junctions between the sarcoplasmic reticulum (SR) and transverse-tubules (TTs). We also demonstrate that these new SR-TT junctions contain the molecular machinery that mediate SOCE: stromal interaction molecule-1 (STIM1), which functions as the SR Ca2+ sensor, and Orai1, the Ca2+-permeable channel in the TT. In addition, EDL muscles isolated from exercised mice exhibit an increased capability of maintaining contractile force during repetitive stimulation in the presence of 2.5 mM extracellular Ca2+, compared to muscles from control mice. This functional difference is significantly reduced by either replacement of extracellular Ca2+ with Mg2+ or the addition of SOCE inhibitors (BTP-2 and 2-APB). We propose that the new SR-TT junctions formed during exercise, and that contain STIM1 and Orai1, function as Ca2+Entry Units (CEUs), structures that provide a pathway to rapidly recover Ca2+ ions from the extracellular space during repetitive muscle activity.
Collapse
Affiliation(s)
- Simona Boncompagni
- CeSI-Met - Center for Research on Ageing and Translational Medicine, University G. d'Annunzio, Chieti, I-66100, Italy.,DNICS - Department of Neuroscience, Imaging and Clinical Sciences, University G. d'Annunzio, Chieti, I-66100, Italy
| | - Antonio Michelucci
- CeSI-Met - Center for Research on Ageing and Translational Medicine, University G. d'Annunzio, Chieti, I-66100, Italy.,DNICS - Department of Neuroscience, Imaging and Clinical Sciences, University G. d'Annunzio, Chieti, I-66100, Italy
| | - Laura Pietrangelo
- CeSI-Met - Center for Research on Ageing and Translational Medicine, University G. d'Annunzio, Chieti, I-66100, Italy.,DNICS - Department of Neuroscience, Imaging and Clinical Sciences, University G. d'Annunzio, Chieti, I-66100, Italy
| | - Robert T Dirksen
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Feliciano Protasi
- CeSI-Met - Center for Research on Ageing and Translational Medicine, University G. d'Annunzio, Chieti, I-66100, Italy. .,DMSI - Department of Medicine and Aging Science, University G. d'Annunzio, Chieti, I-66100, Italy.
| |
Collapse
|
163
|
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.
Collapse
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.
| |
Collapse
|
164
|
Muallem S, Chung WY, Jha A, Ahuja M. Lipids at membrane contact sites: cell signaling and ion transport. EMBO Rep 2017; 18:1893-1904. [PMID: 29030479 DOI: 10.15252/embr.201744331] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 06/10/2017] [Accepted: 09/21/2017] [Indexed: 12/14/2022] Open
Abstract
Communication between organelles is essential to coordinate cellular functions and the cell's response to physiological and pathological stimuli. Organellar communication occurs at membrane contact sites (MCSs), where the endoplasmic reticulum (ER) membrane is tethered to cellular organelle membranes by specific tether proteins and where lipid transfer proteins and cell signaling proteins are located. MCSs have many cellular functions and are the sites of lipid and ion transfer between organelles and generation of second messengers. This review discusses several aspects of MCSs in the context of lipid transfer, formation of lipid domains, generation of Ca2+ and cAMP second messengers, and regulation of ion transporters by lipids.
Collapse
Affiliation(s)
- Shmuel Muallem
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, Bethesda, MD, USA
| | - Woo Young Chung
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, Bethesda, MD, USA
| | - Archana Jha
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, Bethesda, MD, USA
| | - Malini Ahuja
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, Bethesda, MD, USA
| |
Collapse
|
165
|
Choi YJ, Zhu J, Chung S, Siddiqui N, Feng Q, Stathopulos PB. Targeting Cysteine Thiols for in Vitro Site-specific Glycosylation of Recombinant Proteins. J Vis Exp 2017. [PMID: 29053695 DOI: 10.3791/56302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Stromal interaction molecule-1 (STIM1) is a type-I transmembrane protein located on the endoplasmic reticulum (ER) and plasma membranes (PM). ER-resident STIM1 regulates the activity of PM Orai1 channels in a process known as store operated calcium (Ca2+) entry which is the principal Ca2+ signaling process that drives the immune response. STIM1 undergoes post-translational N-glycosylation at two luminal Asn sites within the Ca2+ sensing domain of the molecule. However, the biochemical, biophysical, and structure biological effects of N-glycosylated STIM1 were poorly understood until recently due to an inability to readily obtain high levels of homogeneous N-glycosylated protein. Here, we describe the implementation of an in vitro chemical approach which attaches glucose moieties to specific protein sites applicable to understanding the underlying effects of N-glycosylation on protein structure and mechanism. Using solution nuclear magnetic resonance spectroscopy we assess both efficiency of the modification as well as the structural consequences of the glucose attachment with a single sample. This approach can readily be adapted to study the myriad glycosylated proteins found in nature.
Collapse
Affiliation(s)
- Yoo Jung Choi
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario
| | - Jinhui Zhu
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario
| | - Steve Chung
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario
| | - Naveed Siddiqui
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario
| | - Qingping Feng
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario
| | - Peter B Stathopulos
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario;
| |
Collapse
|
166
|
Inoh Y, Haneda A, Tadokoro S, Yokawa S, Furuno T. Cationic liposomes suppress intracellular calcium ion concentration increase via inhibition of PI3 kinase pathway in mast cells. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:2461-2466. [PMID: 28966111 DOI: 10.1016/j.bbamem.2017.09.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 09/07/2017] [Accepted: 09/27/2017] [Indexed: 11/26/2022]
Abstract
Cationic liposomes are commonly used as vectors to effectively introduce foreign genes (antisense DNA, plasmid DNA, siRNA, etc.) into target cells. Cationic liposomes are also known to affect cellular immunocompetences such as the mast cell function in allergic reactions. In particular, we previously showed that the cationic liposomes bound to the mast cell surface suppress the degranulation induced by cross-linking of high affinity IgE receptors in a time- and dose-dependent manner. This suppression is mediated by impairment of the sustained level of intracellular Ca2+ concentration ([Ca2+]i) via inhibition of store-operated Ca2+ entry (SOCE). Here we study the mechanism underlying an impaired [Ca2+]i increase by cationic liposomes in mast cells. We show that cationic liposomes inhibit the phosphorylation of Akt and PI3 kinases but not Syk and LAT. As a consequence, SOCE is suppressed but Ca2+ release from endoplasmic reticulum (ER) is not. Cationic liposomes inhibit the formation of STIM1 puncta, which is essential to SOCE by interacting with Orai1 following the Ca2+ concentration decrease in the ER. These data suggest that cationic liposomes suppress SOCE by inhibiting the phosphorylation of PI3 and Akt kinases in mast cells.
Collapse
Affiliation(s)
- Yoshikazu Inoh
- School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya 464-8650, Japan.
| | - Aki Haneda
- School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya 464-8650, Japan
| | - Satoshi Tadokoro
- Faculty of Pharma Sciences, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan
| | - Satoru Yokawa
- School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya 464-8650, Japan
| | - Tadahide Furuno
- School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya 464-8650, Japan
| |
Collapse
|
167
|
Optimizing the fragment complementation of APEX2 for detection of specific protein-protein interactions in live cells. Sci Rep 2017; 7:12039. [PMID: 28955036 PMCID: PMC5617831 DOI: 10.1038/s41598-017-12365-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 09/07/2017] [Indexed: 12/23/2022] Open
Abstract
Dynamic protein-protein interactions (PPIs) play crucial roles in cell physiological processes. The protein-fragment complementation (PFC) assay has been developed as a powerful approach for the detection of PPIs, but its potential for identifying protein interacting regions is not optimized. Recently, an ascorbate peroxidase (APEX2)-based proximity-tagging method combined with mass spectrometry was developed to identify potential protein interactions in live cells. In this study, we tested whether APEX2 could be employed for PFC. By screening split APEX2 pairs attached to FK506-binding protein 12 (FKBP) and the FKBP12-rapamycin binding (FRB) domain, which interact with each other only in the presence of rapamycin, we successfully obtained an optimized pair for visualizing the interaction between FRB and FKBP12 with high specificity and sensitivity in live cells. The robustness of this APEX2 pair was confirmed by its application toward detecting the STIM1 and Orial1 homodimers in HEK-293 cells. With a subsequent mass spectrometry analysis, we obtained five different biotinylated sites that were localized to the known interaction region on STIM1 and were only detected when the homodimer formed. These results suggest that our PFC pair of APEX2 provides a potential tool for detecting PPIs and identifying binding regions with high specificity in live cells.
Collapse
|
168
|
The Role of Mitochondria in the Activation/Maintenance of SOCE: Membrane Contact Sites as Signaling Hubs Sustaining Store-Operated Ca2+ Entry. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 993:277-296. [DOI: 10.1007/978-3-319-57732-6_15] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/10/2023]
|
169
|
Drebrin Regulation of Calcium Signaling in Immune Cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017. [PMID: 28865026 DOI: 10.1007/978-4-431-56550-5_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
Store-operated Ca2+ channels are plasma membrane channels that are activated by depletion of intracellular Ca2+ stores, resulting in an increase in intracellular Ca2+; however, little is known about their regulation. Our work has shown that the immunosuppressant compound BTP2, which blocks Ca2+ influx into cells, interacts with the actin-reorganizing protein, drebrin. Here we review the role of drebrin in the regulation of calcium signaling, with a focus on immune cells.
Collapse
|
170
|
He L, Jing J, Zhu L, Tan P, Ma G, Zhang Q, Nguyen NT, Wang J, Zhou Y, Huang Y. Optical control of membrane tethering and interorganellar communication at nanoscales. Chem Sci 2017; 8:5275-5281. [PMID: 28959426 PMCID: PMC5606013 DOI: 10.1039/c7sc01115f] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 05/23/2017] [Indexed: 12/11/2022] Open
Abstract
Endoplasmic reticulum (ER) forms an extensive intracellular membranous network in eukaryotes that dynamically connects and communicates with diverse subcellular compartments such as plasma membrane (PM) through membrane contact sites (MCSs), with the inter-membrane gaps separated by a distance of 10-40 nm. Phosphoinositides (PI) constitute an important class of cell membrane phospholipids shared by many MCSs to regulate a myriad of cellular events, including membrane trafficking, calcium homeostasis and lipid metabolism. By installing photosensitivity into a series of engineered PI-binding domains with minimal sizes, we have created an optogenetic toolkit (designated as 'OptoPB') to enable rapid and reversible control of protein translocation and inter-membrane tethering at MCSs. These genetically-encoded, single-component tools can be used as scaffolds for grafting lipid-binding domains to dissect molecular determinants that govern protein-lipid interactions in living cells. Furthermore, we have demonstrated the use of OptoPB as a versatile fusion tag to photomanipulate protein translocation toward PM for reprogramming of PI metabolism. When tethered to the ER membrane with the insertion of flexible spacers, OptoPB can be applied to reversibly photo-tune the gap distances at nanometer scales between the two organellar membranes at MCSs, and to gauge the distance requirement for the free diffusion of protein complexes into MCSs. Our modular optical tools will find broad applications in non-invasive and remote control of protein subcellular localization and interorganellar contact sites that are critical for cell signaling.
Collapse
Affiliation(s)
- Lian He
- Center for Translational Cancer Research , Institute of Biosciences and Technology , Department of Medical Physiology , College of Medicine , Texas A&M University , Houston , TX 77030 , USA .
| | - Ji Jing
- Center for Translational Cancer Research , Institute of Biosciences and Technology , Department of Medical Physiology , College of Medicine , Texas A&M University , Houston , TX 77030 , USA .
| | - Lei Zhu
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology , Chinese Academy of Sciences , Hefei 230031 , Anhui , China .
| | - Peng Tan
- Center for Translational Cancer Research , Institute of Biosciences and Technology , Department of Medical Physiology , College of Medicine , Texas A&M University , Houston , TX 77030 , USA .
| | - Guolin Ma
- Center for Translational Cancer Research , Institute of Biosciences and Technology , Department of Medical Physiology , College of Medicine , Texas A&M University , Houston , TX 77030 , USA .
| | - Qian Zhang
- Center for Translational Cancer Research , Institute of Biosciences and Technology , Department of Medical Physiology , College of Medicine , Texas A&M University , Houston , TX 77030 , USA .
- Department of Infectious Diseases , Renmin Hospital of Wuhan University , Wuhan , Hubei 430060 , China
| | - Nhung T Nguyen
- Center for Translational Cancer Research , Institute of Biosciences and Technology , Department of Medical Physiology , College of Medicine , Texas A&M University , Houston , TX 77030 , USA .
| | - Junfeng Wang
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology , Chinese Academy of Sciences , Hefei 230031 , Anhui , China .
| | - Yubin Zhou
- Center for Translational Cancer Research , Institute of Biosciences and Technology , Department of Medical Physiology , College of Medicine , Texas A&M University , Houston , TX 77030 , USA .
| | - Yun Huang
- Center for Epigenetics and Disease Prevention , Institute of Biosciences and Technology , Department of Medical Physiology , College of Medicine , Texas A&M University , Houston , TX 77030 , USA .
| |
Collapse
|
171
|
van Vliet AR, Garg AD, Agostinis P. Coordination of stress, Ca2+, and immunogenic signaling pathways by PERK at the endoplasmic reticulum. Biol Chem 2017; 397:649-56. [PMID: 26872313 DOI: 10.1515/hsz-2016-0108] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 02/08/2016] [Indexed: 12/17/2022]
Abstract
The endoplasmic reticulum (ER) is the main coordinator of intracellular Ca2+ signaling, protein synthesis, and folding. The ER is also implicated in the formation of contact sites with other organelles and structures, including mitochondria, plasma membrane (PM), and endosomes, thereby orchestrating through interorganelle signaling pathways, a variety of cellular responses including Ca2+ homeostasis, metabolism, and cell death signaling. Upon loss of its folding capacity, incited by a number of stress signals including those elicited by various anticancer therapies, the unfolded protein response (UPR) is launched to restore ER homeostasis. The ER stress sensor protein kinase RNA-like ER kinase (PERK) is a key mediator of the UPR and its role during ER stress has been largely recognized. However, growing evidence suggests that PERK may govern signaling pathways through UPR-independent functions. Here, we discuss emerging noncanonical roles of PERK with particular relevance for the induction of danger or immunogenic signaling and interorganelle communication.
Collapse
|
172
|
Orai3 channel is the 2-APB-induced endoplasmic reticulum calcium leak. Cell Calcium 2017; 65:91-101. [DOI: 10.1016/j.ceca.2017.01.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 01/17/2017] [Accepted: 01/20/2017] [Indexed: 12/22/2022]
|
173
|
Yen M, Lokteva LA, Lewis RS. Functional Analysis of Orai1 Concatemers Supports a Hexameric Stoichiometry for the CRAC Channel. Biophys J 2017; 111:1897-1907. [PMID: 27806271 DOI: 10.1016/j.bpj.2016.09.020] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 08/29/2016] [Accepted: 09/12/2016] [Indexed: 01/16/2023] Open
Abstract
Store-operated Ca2+ entry occurs through the binding of the endoplasmic reticulum (ER) Ca2+ sensor STIM1 to Orai1, the pore-forming subunit of the Ca2+ release-activated Ca2+ (CRAC) channel. Although the essential steps leading to channel opening have been described, fundamental questions remain, including the functional stoichiometry of the CRAC channel. The crystal structure of Drosophila Orai indicates a hexameric stoichiometry, while studies of linked Orai1 concatemers and single-molecule photobleaching suggest that channels assemble as tetramers. We assessed CRAC channel stoichiometry by expressing hexameric concatemers of human Orai1 and comparing in detail their ionic currents to those of native CRAC channels and channels generated from monomeric Orai1 constructs. Cell surface biotinylation results indicated that Orai1 channels in the plasma membrane were assembled from intact hexameric polypeptides and not from truncated protein products. In addition, the L273D mutation depressed channel activity equally regardless of which Orai1 subunit in the concatemer carried the mutation. Thus, functional channels were generated from intact Orai1 hexamers in which all subunits contributed equally. These hexameric Orai1 channels displayed the biophysical fingerprint of native CRAC channels, including the distinguishing characteristics of gating (store-dependent activation, Ca2+-dependent inactivation, open probability), permeation (ion selectivity, affinity for Ca2+ block, La3+ sensitivity, unitary current magnitude), and pharmacology (enhancement and inhibition by 2-aminoethoxydiphenyl borate). Because permeation characteristics depend strongly on pore geometry, it is unlikely that hexameric and tetrameric pores would display identical Ca2+ affinity, ion selectivity, and unitary current magnitude. Thus, based on the highly similar pore properties of the hexameric Orai1 concatemer and native CRAC channels, we conclude that the CRAC channel functions as a hexamer of Orai1 subunits.
Collapse
Affiliation(s)
- Michelle Yen
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California; Graduate Program in Immunology, Stanford University School of Medicine, Stanford, California
| | - Ludmila A Lokteva
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California
| | - Richard S Lewis
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California; Graduate Program in Immunology, Stanford University School of Medicine, Stanford, California.
| |
Collapse
|
174
|
Chen YJ, Chang CL, Lee WR, Liou J. RASSF4 controls SOCE and ER-PM junctions through regulation of PI(4,5)P 2. J Cell Biol 2017; 216:2011-2025. [PMID: 28600435 PMCID: PMC5496610 DOI: 10.1083/jcb.201606047] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 10/18/2016] [Accepted: 04/27/2017] [Indexed: 11/22/2022] Open
Abstract
RAS association domain family 4 (RASSF4) is involved in tumorigenesis. Chen et al. show that RASSF4 regulates store-operated Ca2+ entry and ER–PM junctions by affecting PI(4,5)P2 levels. RASSF4 interacts with and regulates the activity of ARF6, an upstream regulator of PIP5K and PI(4,5)P2. RAS association domain family 4 (RASSF4) is involved in tumorigenesis and regulation of the Hippo pathway. In this study, we identify new functional roles of RASSF4. First, we discovered that RASSF4 regulates store-operated Ca2+ entry (SOCE), a fundamental Ca2+ signaling mechanism, by affecting the translocation of the endoplasmic reticulum (ER) Ca2+ sensor stromal interaction molecule 1 (STIM1) to ER–plasma membrane (PM) junctions. It was further revealed that RASSF4 regulates the formation of ER–PM junctions and the ER–PM tethering function of extended synaptotagmins E-Syt2 and E-Syt3. Moreover, steady-state PM phosphatidylinositol 4,5-bisphosphate (PI[4,5]P2) levels, important for localization of STIM1 and E-Syts at ER–PM junctions, were reduced in RASSF4-knockdown cells. Furthermore, we demonstrated that RASSF4 interacts with and regulates the activity of adenosine diphosphate ribosylation factor 6 (ARF6), a small G protein and upstream regulator of type I phosphatidylinositol phosphate kinases (PIP5Ks) and PM PI(4,5)P2 levels. Overall, our study suggests that RASSF4 controls SOCE and ER–PM junctions through ARF6-dependent regulation of PM PI(4,5)P2 levels, pivotal for a variety of physiological processes.
Collapse
Affiliation(s)
- Yu-Ju Chen
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Chi-Lun Chang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Wan-Ru Lee
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Jen Liou
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX
| |
Collapse
|
175
|
Chang CL, Chen YJ, Liou J. ER-plasma membrane junctions: Why and how do we study them? BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:1494-1506. [PMID: 28554772 DOI: 10.1016/j.bbamcr.2017.05.018] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 05/09/2017] [Accepted: 05/17/2017] [Indexed: 12/17/2022]
Abstract
Endoplasmic reticulum (ER)-plasma membrane (PM) junctions are membrane microdomains important for communication between the ER and the PM. ER-PM junctions were first reported in muscle cells in 1957, but mostly ignored in non-excitable cells due to their scarcity and lack of functional significance. In 2005, the discovery of stromal interaction molecule 1 (STIM1) mediating a universal Ca2+ feedback mechanism at ER-PM junctions in mammalian cells led to a resurgence of research interests toward ER-PM junctions. In the past decade, several major advancements have been made in this emerging topic in cell biology, including the generation of tools for labeling ER-PM junctions and the unraveling of mechanisms underlying regulation and functions of ER-PM junctions. This review summarizes early studies, recently developed tools, and current advances in the characterization and understanding of ER-PM junctions. This article is part of a Special Issue entitled: Membrane Contact Sites edited by Christian Ungermann and Benoit Kornmann.
Collapse
Affiliation(s)
- Chi-Lun Chang
- Department of Physiology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yu-Ju Chen
- Department of Physiology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jen Liou
- Department of Physiology, UT Southwestern Medical Center, Dallas, TX 75390, USA.
| |
Collapse
|
176
|
Maher P, van Leyen K, Dey PN, Honrath B, Dolga A, Methner A. The role of Ca 2+ in cell death caused by oxidative glutamate toxicity and ferroptosis. Cell Calcium 2017; 70:47-55. [PMID: 28545724 DOI: 10.1016/j.ceca.2017.05.007] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Revised: 05/11/2017] [Accepted: 05/11/2017] [Indexed: 12/21/2022]
Abstract
Ca2+ ions play a fundamental role in cell death mediated by oxidative glutamate toxicity or oxytosis, a form of programmed cell death similar and possibly identical to other forms of cell death like ferroptosis. Ca2+ influx from the extracellular space occurs late in a cascade characterized by depletion of the intracellular antioxidant glutathione, increases in cytosolic reactive oxygen species and mitochondrial dysfunction. Here, we aim to compare oxidative glutamate toxicity with ferroptosis, address the signaling pathways that culminate in Ca2+ influx and cell death and discuss the proteins that mediate this. Recent evidence hints toward a role of the machinery responsible for store-operated Ca2+ entry (SOCE), which refills the endoplasmic reticulum (ER) after receptor-mediated ER Ca2+ release or other forms of store depletion. Pharmacological inhibition of SOCE or transcriptional downregulation of proteins involved in SOCE like the ER Ca2+ sensor STIM1, the plasma membrane Ca2+ channels Orai1 and TRPC1 and the linking protein Homer protects against oxidative glutamate toxicity and direct oxidative stress caused by hydrogen peroxide or 1-methyl-4-phenylpyridinium (MPP+) injury, a cellular model of Parkinson's disease. This suggests that SOCE inhibition might have some potential therapeutic effects in human disease associated with oxidative stress like neurodegenerative disorders.
Collapse
Affiliation(s)
- Pamela Maher
- Cellular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
| | | | - Partha Narayan Dey
- University Medical Center and Focus Program Translational Neuroscience (FTN) of the Johannes Gutenberg University Mainz, Department of Neurology, Mainz, Germany
| | - Birgit Honrath
- Department of Molecular Pharmacology, University of Groningen, Groningen, The Netherlands
| | - Amalia Dolga
- Department of Molecular Pharmacology, University of Groningen, Groningen, The Netherlands
| | - Axel Methner
- University Medical Center and Focus Program Translational Neuroscience (FTN) of the Johannes Gutenberg University Mainz, Department of Neurology, Mainz, Germany.
| |
Collapse
|
177
|
Lyon K, Adams A, Piva M, Asghari P, Moore ED, Vogl AW. Ca2+ signaling machinery is present at intercellular junctions and structures associated with junction turnover in rat Sertoli cells†. Biol Reprod 2017; 96:1288-1302. [DOI: 10.1093/biolre/iox042] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 05/08/2017] [Indexed: 11/13/2022] Open
|
178
|
STIM1 and STIM2 differently regulate endogenous Ca 2+ entry and promote TGF-β-induced EMT in breast cancer cells. Biochem Biophys Res Commun 2017; 488:74-80. [PMID: 28479254 DOI: 10.1016/j.bbrc.2017.05.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 05/02/2017] [Indexed: 01/27/2023]
Abstract
The Ca2+ sensor proteins STIM1 and STIM2 are crucial elements of store-operated calcium entry (SOCE) in breast cancer cells. Increased SOCE activity may contribute to epithelial-mesenchymal transitions (EMT) and increase cell migration and invasion. However, the roles of STIM1 and STIM2 in TGF-β-induced EMT are still unclear. In this study, we demonstrate roles of STIMs in TGF-β-induced EMT in breast cancer cells. In particular, STIM1 and STIM2 expression affected TGF-β-induced EMT by mediating SOCE in MDA-MB-231 and MCF-7 breast cancer cells. The specific SOCE inhibitor YM58483 blocked TGF-β-induced EMT, and differing effects of STIM1 and STIM2 on TGF-β-induced EMT correlated with differing roles in SOCE. Finally, we showed that STIM2 is associated with non-store-operated calcium entry (non-SOCE) during TGF-β-induced EMT, whereas STIM1 is not. What's more, non-SOCE have a large possibility to be ROCE. In conclusion, STIM1 and STIM2 proteins play important roles in TGF-β-induced EMT and these effects are related to both SOCE and non-SOCE.
Collapse
|
179
|
Yeung PSW, Yamashita M, Prakriya M. Pore opening mechanism of CRAC channels. Cell Calcium 2017; 63:14-19. [PMID: 28108030 PMCID: PMC5466454 DOI: 10.1016/j.ceca.2016.12.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 12/21/2016] [Accepted: 12/21/2016] [Indexed: 02/05/2023]
Abstract
Three decades ago, James W. Putney Jr. conceptualized the idea of store-operated calcium entry (SOCE) to explain how depletion of endoplasmic reticulum (ER) Ca2+ stores evokes Ca2+ influx across the plasma membrane. Since the publication of this highly influential idea, it is now established that SOCE is universal among non-excitable and probably even many types of excitable cells, and contributes to numerous effector functions impacting immunity, muscle contraction, and brain function. The molecules encoding SOCE, the STIM and Orai proteins, are now known and our understanding of how this pathway is activated in response to ER Ca2+ store depletion has advanced significantly. In this review, we summarize the current knowledge of how Orai1 channels are activated by STIM1, focusing on recent work supporting a hydrophobic gating mechanism for the opening of the Orai1 channel pore.
Collapse
Affiliation(s)
- Priscilla S-W Yeung
- Department of Pharmacology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, United States
| | - Megumi Yamashita
- Department of Pharmacology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, United States
| | - Murali Prakriya
- Department of Pharmacology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, United States.
| |
Collapse
|
180
|
Stathopulos PB, Ikura M. Store operated calcium entry: From concept to structural mechanisms. Cell Calcium 2017; 63:3-7. [DOI: 10.1016/j.ceca.2016.11.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 11/24/2016] [Accepted: 11/24/2016] [Indexed: 11/16/2022]
|
181
|
Petersen OH, Courjaret R, Machaca K. Ca 2+ tunnelling through the ER lumen as a mechanism for delivering Ca 2+ entering via store-operated Ca 2+ channels to specific target sites. J Physiol 2017; 595:2999-3014. [PMID: 28181236 PMCID: PMC5430212 DOI: 10.1113/jp272772] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 01/05/2017] [Indexed: 01/02/2023] Open
Abstract
Ca2+ signalling is perhaps the most universal and versatile mechanism regulating a wide range of cellular processes. Because of the many different calcium‐binding proteins distributed throughout cells, signalling precision requires localized rises in the cytosolic Ca2+ concentration. In electrically non‐excitable cells, for example epithelial cells, this is achieved by primary release of Ca2+ from the endoplasmic reticulum via Ca2+ release channels placed close to the physiological target. Because any rise in the cytosolic Ca2+ concentration activates Ca2+ extrusion, and in order for cells not to run out of Ca2+, there is a need for compensatory Ca2+ uptake from the extracellular fluid. This Ca2+ uptake occurs through a process known as store‐operated Ca2+ entry. Ideally Ca2+ entering the cell should not diffuse to the target site through the cytosol, as this would potentially activate undesirable processes. Ca2+ tunnelling through the lumen of the endoplasmic reticulum is a mechanism for delivering Ca2+ entering via store‐operated Ca2+ channels to specific target sites, and this process has been described in considerable detail in pancreatic acinar cells and oocytes. Here we review the most important evidence and present a generalized concept.
![]()
Collapse
Affiliation(s)
- Ole H Petersen
- MRC Group, School of Biosciences and Systems Immunity Research Institute, Cardiff University, Cardiff, CF10 3AX, UK
| | - Raphael Courjaret
- Department of Physiology and Biophysics, Weill Cornell Medicine Qatar, Education City, Qatar Foundation, PO Box 24144, Doha, Qatar
| | - Khaled Machaca
- Department of Physiology and Biophysics, Weill Cornell Medicine Qatar, Education City, Qatar Foundation, PO Box 24144, Doha, Qatar
| |
Collapse
|
182
|
The role of STIM1 and SOCE in smooth muscle contractility. Cell Calcium 2017; 63:60-65. [PMID: 28372809 DOI: 10.1016/j.ceca.2017.02.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 02/13/2017] [Accepted: 02/13/2017] [Indexed: 11/20/2022]
Abstract
Contraction is a central feature for skeletal, cardiac and smooth muscle; this unique feature is largely dependent on calcium (Ca2+) signaling and therefore maintenance of internal Ca2+ stores. Stromal interaction molecule 1 (STIM1) is a single-pass transmembrane protein that functions as a Ca2+ sensor for the activation store-operated calcium channels (SOCCs) on the plasma membrane in response to depleted internal sarco(endo)plasmic (S/ER) reticulum Ca2+ stores. STIM1 was initially characterized in non-excitable cells; however, evidence from both animal models and human mutations suggests a role for STIM1 in modulating Ca2+ homeostasis in excitable tissues as well. STIM1-dependent SOCE is particularly important in tissues undergoing sustained contraction, leading us to believe STIM1 may play a role in smooth muscle contraction. To date, the role of STIM1 in smooth muscle is unknown. In this review, we provide a brief overview of the role of STIM1-dependent SOCE in striated muscle and build off that knowledge to investigate whether STIM1 contributes to smooth muscle contractility. We conclude by discussing the translational implications of targeting STIM1 in the treatment of smooth muscle disorders.
Collapse
|
183
|
Atlastin regulates store-operated calcium entry for nerve growth factor-induced neurite outgrowth. Sci Rep 2017; 7:43490. [PMID: 28240257 PMCID: PMC5327485 DOI: 10.1038/srep43490] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 01/24/2017] [Indexed: 11/20/2022] Open
Abstract
Homotypic membrane fusion of the endoplasmic reticulum (ER) is mediated by a class of dynamin-like GTPases known as atlastin (ATL). Depletion of or mutations in ATL cause an unbranched ER morphology and hereditary spastic paraplegia (HSP), a neurodegenerative disease characterized by axon shortening in corticospinal motor neurons and progressive spasticity of the lower limbs. How ER shaping is linked to neuronal defects is poorly understood. Here, we show that dominant-negative mutants of ATL1 in PC-12 cells inhibit nerve growth factor (NGF)-induced neurite outgrowth. Overexpression of wild-type or mutant ATL1 or depletion of ATLs alters ER morphology and affects store-operated calcium entry (SOCE) by decreasing STIM1 puncta formation near the plasma membrane upon calcium depletion of the ER. In addition, blockage of the STIM1-Orai pathway effectively abolishes neurite outgrowth of PC-12 cells stimulated by NGF. These results suggest that SOCE plays an important role in neuronal regeneration, and mutations in ATL1 may cause HSP, partly by undermining SOCE.
Collapse
|
184
|
Abstract
Ca2+ influx across the plasma membrane is a key component of the receptor-evoked Ca2+ signaling that mediate numerous cell functions and reload the ER after partial or full ER Ca2+ store depletion. Ca2+ influx is activated in response to Ca2+ release from the ER, a concept developed by Jim Putney, and the channels mediating the influx are thus called store-operated Ca2+ influx channels, or SOCs. The molecular identity of the SOCs has been determined with the identification of the TRPC channels, STIM1 and the Orai channels. These channels are targeted to, operate and are regulated when at the ER/PM junctions. ER/PM junctions are a form of membrane contact sites (MCSs) that are present in all parts of the cells, where the ER makes contacts with cellular membranes and organelles. MCSs have many cellular functions, and are the sites of lipid and Ca2+ transport and delivery between organelles. This short review discusses aspects of MCSs in the context of Ca2+ transport.
Collapse
Affiliation(s)
- Woo Young Chung
- From the Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institute of Health, Bethesda MD 20892, United States
| | - Archana Jha
- From the Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institute of Health, Bethesda MD 20892, United States
| | - Malini Ahuja
- From the Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institute of Health, Bethesda MD 20892, United States
| | - Shmuel Muallem
- From the Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institute of Health, Bethesda MD 20892, United States.
| |
Collapse
|
185
|
Mukherjee S, Karolak A, Debant M, Buscaglia P, Renaudineau Y, Mignen O, Guida WC, Brooks WH. Molecular Dynamics Simulations of Membrane-Bound STIM1 to Investigate Conformational Changes during STIM1 Activation upon Calcium Release. J Chem Inf Model 2017; 57:335-344. [PMID: 28151650 DOI: 10.1021/acs.jcim.6b00475] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Calcium is involved in important intracellular processes, such as intracellular signaling from cell membrane receptors to the nucleus. Typically, calcium levels are kept at less than 100 nM in the nucleus and cytosol, but some calcium is stored in the endoplasmic reticulum (ER) lumen for rapid release to activate intracellular calcium-dependent functions. Stromal interacting molecule 1 (STIM1) plays a critical role in early sensing of changes in the ER's calcium level, especially when there is a sudden release of stored calcium from the ER. Inactive STIM1, which has a bound calcium ion, is activated upon ion release. Following activation of STIM1, there is STIM1-assisted initiation of extracellular calcium entry through channels in the cell membrane. This extracellular calcium entering the cell then amplifies intracellular calcium-dependent actions. At the end of the process, ER levels of stored calcium are reestablished. The main focus of this work was to study the conformational changes accompanying homo- or heterodimerization of STIM1. For this purpose, the ER luminal portion of STIM1 (residues 58-236), which includes the sterile alpha motif (SAM) domain plus the calcium-binding EF-hand domains 1 and 2 attached to the STIM1 transmembrane region (TM), was modeled and embedded in a virtual membrane. Next, molecular dynamics simulations were performed to study the conformational changes that take place during STIM1 activation and subsequent protein-protein interactions. Indeed, the simulations revealed exposure of residues in the EF-hand domains, which may be important for dimerization steps. Altogether, understanding conformational changes in STIM1 can help in drug discovery when targeting this key protein in intracellular calcium functions.
Collapse
Affiliation(s)
- Sreya Mukherjee
- Department of Chemistry, University of South Florida , Tampa, Florida 33620, United States
| | - Aleksandra Karolak
- Department of Chemistry, University of South Florida , Tampa, Florida 33620, United States
| | - Marjolaine Debant
- INSERM ESPRI, ERI29/EA2216 Laboratory of Immunotherapy and B Cell Pathologies, Laboratory of Immunology and Immunotherapy, CHRU Morvan, European University of Brittany , F29609 Brest, France.,Network "Ion channels and cancer-Cancéropole Grand Ouest (IC-CGO)" , F29609 Brest, France.,INSERM U1078, Brest University Medical School , F29609 Brest, France
| | - Paul Buscaglia
- Network "Ion channels and cancer-Cancéropole Grand Ouest (IC-CGO)" , F29609 Brest, France.,INSERM U1078, Brest University Medical School , F29609 Brest, France
| | - Yves Renaudineau
- INSERM ESPRI, ERI29/EA2216 Laboratory of Immunotherapy and B Cell Pathologies, Laboratory of Immunology and Immunotherapy, CHRU Morvan, European University of Brittany , F29609 Brest, France.,Network "Ion channels and cancer-Cancéropole Grand Ouest (IC-CGO)" , F29609 Brest, France
| | - Olivier Mignen
- Network "Ion channels and cancer-Cancéropole Grand Ouest (IC-CGO)" , F29609 Brest, France.,INSERM U1078, Brest University Medical School , F29609 Brest, France
| | - Wayne C Guida
- Department of Chemistry, University of South Florida , Tampa, Florida 33620, United States
| | - Wesley H Brooks
- Department of Chemistry, University of South Florida , Tampa, Florida 33620, United States
| |
Collapse
|
186
|
From Stores to Sinks: Structural Mechanisms of Cytosolic Calcium Regulation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 981:215-251. [PMID: 29594864 DOI: 10.1007/978-3-319-55858-5_10] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
All eukaryotic cells have adapted the use of the calcium ion (Ca2+) as a universal signaling element through the evolution of a toolkit of Ca2+ sensor, buffer and effector proteins. Among these toolkit components, integral and peripheral proteins decorate biomembranes and coordinate the movement of Ca2+ between compartments, sense these concentration changes and elicit physiological signals. These changes in compartmentalized Ca2+ levels are not mutually exclusive as signals propagate between compartments. For example, agonist induced surface receptor stimulation can lead to transient increases in cytosolic Ca2+ sourced from endoplasmic reticulum (ER) stores; the decrease in ER luminal Ca2+ can subsequently signal the opening surface channels which permit the movement of Ca2+ from the extracellular space to the cytosol. Remarkably, the minuscule compartments of mitochondria can function as significant cytosolic Ca2+ sinks by taking up Ca2+ in a coordinated manner. In non-excitable cells, inositol 1,4,5 trisphosphate receptors (IP3Rs) on the ER respond to surface receptor stimulation; stromal interaction molecules (STIMs) sense the ER luminal Ca2+ depletion and activate surface Orai1 channels; surface Orai1 channels selectively permit the movement of Ca2+ from the extracellular space to the cytosol; uptake of Ca2+ into the matrix through the mitochondrial Ca2+ uniporter (MCU) further shapes the cytosolic Ca2+ levels. Recent structural elucidations of these key Ca2+ toolkit components have improved our understanding of how they function to orchestrate precise cytosolic Ca2+ levels for specific physiological responses. This chapter reviews the atomic-resolution structures of IP3R, STIM1, Orai1 and MCU elucidated by X-ray crystallography, electron microscopy and NMR and discusses the mechanisms underlying their biological functions in their respective compartments within the cell.
Collapse
|
187
|
Fahrner M, Schindl R, Muik M, Derler I, Romanin C. The STIM-Orai Pathway: The Interactions Between STIM and Orai. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 993:59-81. [PMID: 28900909 DOI: 10.1007/978-3-319-57732-6_4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A primary Ca2+ entry pathway in non-excitable cells is established by the Ca2+ release-activated Ca2+ channels. Their two limiting molecular components include the Ca2+-sensor protein STIM1 located in the endoplasmic reticulum and the Orai channel in the plasma membrane. STIM1 senses the luminal Ca2+ content, and store depletion induces its oligomerization into puncta-like structures, thereby triggering coupling to as well as activation of Orai channels. A C-terminal STIM1 domain is assumed to couple to both C- and N-terminal, cytosolic strands of Orai, accomplishing gating of the channel. Here we highlight the inter- and intramolecular steps of the STIM1-Orai signaling cascade together with critical sites of the pore structure that accomplishes Ca2+ permeation.
Collapse
Affiliation(s)
- Marc Fahrner
- Institute of Biophysics, Johannes Kepler University Linz, 4020, Linz, Austria.
| | - Rainer Schindl
- Institute of Biophysics, Johannes Kepler University Linz, 4020, Linz, Austria
| | - Martin Muik
- Institute of Biophysics, Johannes Kepler University Linz, 4020, Linz, Austria
| | - Isabella Derler
- Institute of Biophysics, Johannes Kepler University Linz, 4020, Linz, Austria
| | - Christoph Romanin
- Institute of Biophysics, Johannes Kepler University Linz, 4020, Linz, Austria.
| |
Collapse
|
188
|
Spät A, Szanda G. The Role of Mitochondria in the Activation/Maintenance of SOCE: Store-Operated Ca 2+ Entry and Mitochondria. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 993:257-275. [PMID: 28900919 DOI: 10.1007/978-3-319-57732-6_14] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Mitochondria extensively modify virtually all cellular Ca2+ transport processes, and store-operated Ca2+ entry (SOCE) is no exception to this rule. The interaction between SOCE and mitochondria is complex and reciprocal, substantially altering and, ultimately, fine-tuning both capacitative Ca2+ influx and mitochondrial function. Mitochondria, owing to their considerable Ca2+ accumulation ability, extensively buffer the cytosolic Ca2+ in their vicinity. In turn, the accumulated ion is released back into the neighboring cytosol during net Ca2+ efflux. Since store depletion itself and the successive SOCE are both Ca2+-regulated phenomena, mitochondrial Ca2+ handling may have wide-ranging effects on capacitative Ca2+ influx at any given time. In addition, mitochondria may also produce or consume soluble factors known to affect store-operated channels. On the other hand, Ca2+ entering the cell during SOCE is sensed by mitochondria, and the ensuing mitochondrial Ca2+ uptake boosts mitochondrial energy metabolism and, if Ca2+ overload occurs, may even lead to apoptosis or cell death. In several cell types, mitochondria seem to be sterically excluded from the confined space that forms between the plasma membrane (PM) and endoplasmic reticulum (ER) during SOCE. This implies that high-Ca2+ microdomains comparable to those observed between the ER and mitochondria do not form here. In the following chapter, the above aspects of the many-sided SOCE-mitochondrion interplay will be discussed in greater detail.
Collapse
Affiliation(s)
- András Spät
- Department of Physiology, Semmelweis University Medical School, POB 2, 1428, Budapest, Hungary.
- Laboratory of Molecular Physiology, Hungarian Academy of Sciences, Budapest, Hungary.
| | - Gergö Szanda
- Department of Physiology, Semmelweis University Medical School, POB 2, 1428, Budapest, Hungary
| |
Collapse
|
189
|
Organelle Communication at Membrane Contact Sites (MCS): From Curiosity to Center Stage in Cell Biology and Biomedical Research. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 997:1-12. [DOI: 10.1007/978-981-10-4567-7_1] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
190
|
Lopez JJ, Salido GM, Rosado JA. Cardiovascular and Hemostatic Disorders: SOCE and Ca 2+ Handling in Platelet Dysfunction. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 993:453-472. [PMID: 28900928 DOI: 10.1007/978-3-319-57732-6_23] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Among the Ca2+ entry mechanisms in platelets, store-operated Ca2+ entry (SOCE) plays a prominent role as it is necessary to achieve full activation of platelet functions and replenish intracellular Ca2+ stores. In platelets, as in other non-excitable cells, SOCE has been reported to involve the activation of plasma membrane channels by the ER Ca2+ sensor STIM1. Despite electrophysiological studies are not possible in human platelets, indirect analyses have revealed that the Ca2+-permeable channels involve Orai1 and, most likely, TRPC1 subunits. A relevant role for the latter has not been found in mouse platelets. There is a body of evidence revealing a number of abnormalities in SOCE or in its molecular regulators that result in qualitative platelet disorders and, as a consequence, altered platelet responsiveness upon stimulation with multiple physiological agonists. Platelet SOCE abnormalities include STIM1 and Orai1 mutations. This chapter summarizes the current knowledge in this field, as well as the disorders associated to platelet SOCE dysfunction.
Collapse
Affiliation(s)
- Jose J Lopez
- Cell Physiology Research Group, Department of Physiology, University of Extremadura, Cáceres, Spain
| | - Gines M Salido
- Cell Physiology Research Group, Department of Physiology, University of Extremadura, Cáceres, Spain
| | - Juan A Rosado
- Cell Physiology Research Group, Department of Physiology, University of Extremadura, Cáceres, Spain.
| |
Collapse
|
191
|
Immunological Disorders: Regulation of Ca 2+ Signaling in T Lymphocytes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 993:397-424. [PMID: 28900926 DOI: 10.1007/978-3-319-57732-6_21] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Engagement of T cell receptors (TCRs) with cognate antigens triggers cascades of signaling pathways in helper T cells. TCR signaling is essential for the effector function of helper T cells including proliferation, differentiation, and cytokine production. It also modulates effector T cell fate by inducing cell death, anergy (nonresponsiveness), exhaustion, and generation of regulatory T cells. One of the main axes of TCR signaling is the Ca2+-calcineurin-nuclear factor of activated T cells (NFAT) signaling pathway. Stimulation of TCRs triggers depletion of intracellular Ca2+ store and, in turn, activates store-operated Ca2+ entry (SOCE) to raise the intracellular Ca2+ concentration. SOCE in T cells is mediated by the Ca2+ release-activated Ca2+ (CRAC) channels, which have been very well characterized in terms of their electrophysiological properties. Identification of STIM1 as a sensor to detect depletion of the endoplasmic reticulum (ER) Ca2+ store and Orai1 as the pore subunit of CRAC channels has dramatically advanced our understanding of the regulatory mechanism of Ca2+ signaling in T cells. In this review, we discuss our current understanding of Ca2+ signaling in T cells with specific focus on the mechanism of CRAC channel activation and regulation via protein interactions. In addition, we will discuss the role of CRAC channels in effector T cells, based on the analyses of genetically modified animal models.
Collapse
|
192
|
STIM-TRP Pathways and Microdomain Organization: Contribution of TRPC1 in Store-Operated Ca 2+ Entry: Impact on Ca 2+ Signaling and Cell Function. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 993:159-188. [PMID: 28900914 DOI: 10.1007/978-3-319-57732-6_9] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Store-operated calcium entry (SOCE) is a ubiquitous Ca2+ entry pathway that is activated in response to depletion of ER-Ca2+ stores and critically controls the regulation of physiological functions in a wide variety of cell types. The transient receptor potential canonical (TRPC) channels (TRPCs 1-7), which are activated by stimuli leading to PIP2 hydrolysis, were first identified as molecular components of SOCE channels. While TRPC1 was associated with SOCE and regulation of function in several cell types, none of the TRPC members displayed I CRAC, the store-operated current identified in lymphocytes and mast cells. Intensive search finally led to the identification of Orai1 and STIM1 as the primary components of the CRAC channel. Orai1 was established as the pore-forming channel protein and STIM1 as the ER-Ca2+ sensor protein involved in activation of Orai1. STIM1 also activates TRPC1 via a distinct domain in its C-terminus. However, TRPC1 function depends on Orai1-mediated Ca2+ entry, which triggers recruitment of TRPC1 into the plasma membrane where it is activated by STIM1. TRPC1 and Orai1 form distinct store-operated Ca2+ channels that regulate specific cellular functions. It is now clearly established that regulation of TRPC1 trafficking can change plasma membrane levels of the channel, the phenotype of the store-operated Ca2+ current, as well as pattern of SOCE-mediated [Ca2+]i signals. Thus, TRPC1 is activated downstream of Orai1 and modifies the initial [Ca2+]i signal generated by Orai1. This review will highlight current concepts of the activation and regulation of TRPC1 channels and its impact on cell function.
Collapse
|
193
|
When under pressure, get closer: PERKing up membrane contact sites during ER stress. Biochem Soc Trans 2016; 44:499-504. [PMID: 27068961 DOI: 10.1042/bst20150272] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Indexed: 02/06/2023]
Abstract
The endoplasmic reticulum (ER) is the main hub of cellular Ca(2+)signalling and protein synthesis and folding. The ER moreover is the central player in the formation of contact sites with other organelles and structures, including mitochondria, plasma membrane (PM) and endosomes. The most studied of these, the ER-mitochondria contact sites, are crucial regulators of cellular Ca(2+)homoeostasis, metabolism and cell death signalling. Protein kinase RNA-like ER kinase (PERK), an ER stress kinase and crucial signalling protein in the unfolded protein response (UPR), was found to be able to orchestrate contact sites between the ER and mitochondria and to be indispensable for the pre-apoptotic trafficking of calreticulin (CRT) at the PM during immunogenic cell death (ICD). Furthermore, PERK has recently been linked with ER and PM contact sites through the mechanism of store-operated Ca(2+)entry (SOCE). Here we discuss emerging findings disclosing novel roles of the ER stress sensor PERK in orchestrating inter-organellar communication in the context of ER stress.
Collapse
|
194
|
Supramolecular architecture of endoplasmic reticulum-plasma membrane contact sites. Biochem Soc Trans 2016; 44:534-40. [PMID: 27068966 DOI: 10.1042/bst20150279] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Indexed: 11/17/2022]
Abstract
The endoplasmic reticulum (ER) forms membrane contact sites (MCS) with most other cellular organelles and the plasma membrane (PM). These ER-PM MCS, where the membranes of the ER and PM are closely apposed, were discovered in the early days of electron microscopy (EM), but only recently are we starting to understand their functional and structural diversity. ER-PM MCS are nowadays known to mediate excitation-contraction coupling (ECC) in striated muscle cells and to play crucial roles in Ca(2+)and lipid homoeostasis in all metazoan cells. A common feature across ER-PM MCS specialized in different functions is the preponderance of cooperative phenomena that result in the formation of large supramolecular assemblies. Therefore, characterizing the supramolecular architecture of ER-PM MCS is critical to understand their mechanisms of function. Cryo-electron tomography (cryo-ET) is a powerful EM technique uniquely positioned to address this issue, as it allows 3D imaging of fully hydrated, unstained cellular structures at molecular resolution. In this review I summarize our current structural knowledge on the molecular organization of ER-PM MCS and its functional implications, with special emphasis on the emerging contributions of cryo-ET.
Collapse
|
195
|
Abstract
Membrane contact sites (MCSs) are subcellular regions where the membranes of distinct organelles come into close apposition. These specialized areas of the cell, which are involved in inter-organelle metabolite exchange, are scaffolded by specific complexes. STARD3 [StAR (steroidogenic acute regulatory protein)-related lipid transfer domain-3] and its close paralogue STARD3NL (STARD3 N-terminal like) are involved in the formation of contacts between late-endosomes and the endoplasmic reticulum (ER). The lipid transfer protein (LTP) STARD3 and STARD3NL, which are both anchored on the limiting membrane of late endosomes (LEs), interact with ER-anchored VAP [VAMP (vesicle-associated membrane protein)-associated protein] (VAP-A and VAP-B) proteins. This direct interaction allows ER-endosome contact formation. STARD3 or STARD3NL-mediated ER-endosome contacts, which affect endosome dynamics, are believed to be involved in cholesterol transport.
Collapse
|
196
|
Parekh AB. Regulation of CRAC channels by Ca 2+-dependent inactivation. Cell Calcium 2016; 63:20-23. [PMID: 28043696 DOI: 10.1016/j.ceca.2016.12.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 12/14/2016] [Accepted: 12/15/2016] [Indexed: 12/27/2022]
Abstract
CRAC channels are a major route for Ca2+ influx in eukaryotic cells. The channels show prominent Ca2+-dependent inactivation through two spatially and temporally distinct mechanisms: fast inactivation, which develops over milliseconds and is triggered by Ca2+ near the mouth of the channel and slow inactivation, which arises over tens of seconds and requires a rise in global cytosolic Ca2+. Slow inactivation is controlled physiologically by Ca2+ uptake into mitochondria through the MCU. Site-directed mutagenesis studies on STIM1 and Orai1 have led to new molecular insight into how fast inactivation occurs. This review describes properties and molecular mechanisms that contribute to these important Ca2+-dependent inhibitory pathways.
Collapse
Affiliation(s)
- Anant B Parekh
- Department of Physiology, Anatomy and Genetics, Parks Road Oxford OX1 3PT, UK.
| |
Collapse
|
197
|
Pathophysiological Significance of Store-Operated Calcium Entry in Megakaryocyte Function: Opening New Paths for Understanding the Role of Calcium in Thrombopoiesis. Int J Mol Sci 2016; 17:ijms17122055. [PMID: 27941645 PMCID: PMC5187855 DOI: 10.3390/ijms17122055] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 11/28/2016] [Accepted: 11/28/2016] [Indexed: 12/16/2022] Open
Abstract
Store-Operated Calcium Entry (SOCE) is a universal calcium (Ca2+) influx mechanism expressed by several different cell types. It is now known that Stromal Interaction Molecule (STIM), the Ca2+ sensor of the intracellular compartments, together with Orai and Transient Receptor Potential Canonical (TRPC), the subunits of Ca2+ permeable channels on the plasma membrane, cooperate in regulating multiple cellular functions as diverse as proliferation, differentiation, migration, gene expression, and many others, depending on the cell type. In particular, a growing body of evidences suggests that a tight control of SOCE expression and function is achieved by megakaryocytes along their route from hematopoietic stem cells to platelet production. This review attempts to provide an overview about the SOCE dynamics in megakaryocyte development, with a focus on most recent findings related to its involvement in physiological and pathological thrombopoiesis.
Collapse
|
198
|
Ji Y, Guo X, Zhang Z, Huang Z, Zhu J, Chen QH, Gui L. CaMKIIδ meditates phenylephrine induced cardiomyocyte hypertrophy through store-operated Ca 2+ entry. Cardiovasc Pathol 2016; 27:9-17. [PMID: 27940402 DOI: 10.1016/j.carpath.2016.11.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 11/10/2016] [Accepted: 11/18/2016] [Indexed: 01/01/2023] Open
Abstract
Evidence suggests that store-operated Ca2+ entry (SOCE) is involved in the hypertrophy of cardiomyocytes. The signaling mechanisms of SOCE contributing to cardiac hypertrophy following phenylephrine (PE) stimulation are not fully understood. Ca2+/calmodulin-dependent protein kinase II δ (CaMKIIδ) plays an important role in regulating intracellular Ca2+ hemostasis and function in the cardimyocytes. This study is aimed to determine the role of CaMKIIδ in regulating the PE-induced myocardial hypertrophy and the associated molecular signaling mechanisms. We used primary cultures of neonatal cardimyocytes isolated from the left ventricle of Sprague Dawley rats to investigate the effects of CaMKIIδ on myocardial hypertrophy and intracellular Ca2+ mobilization. We found that the expression of CaMKIIδ was enhanced in PE-induced hypertrophic cardiomyocytes. CaMKIIδ siRNA, CaMKII inhibitor KN93, and SOCE blocker BTP2 attenuated the increase in the expression of CaMKIIδ and normalized the hypertrophic markers, atrial natriuretic peptide and brain natriuretic peptide, and size of cardiomyocytes induced by PE stimulation. The protein level of stromal interaction molecule 1 and Orai1, the essential components of the SOCE, is also enhanced in hypertrophic cardiomyocytes, which were normalized by CaMKIIδ siRNA and KN93 treatment. Hypertrophic cardiomyocytes showed an increase in the peak of Ca2+ transient following store depletion, which was inhibited by SOCE blocker BTP2, CaMKIIδ siRNA, and KN93. The Ca2+ currents through Ca2+ release-activated Ca2+ channels were increased in PE-treated cardiomyocytes and were attenuated by CaMKIIδ siRNA and KN93. These data indicate that PE-induced myocardial hypertrophy requires a complex signaling pathway that involves activation of both CaMKIIδ and SOCE. In conclusion, these studies reveal that up-regulation of CaMKIIδ may contribute to the PE-induced myocardial hypertrophy through the activation of SOCE expressed in the cardiomyocytes.
Collapse
Affiliation(s)
- Yawei Ji
- Department of Cardiology, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, PR China
| | - Xin Guo
- Department of Urology, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, PR China
| | - Zhe Zhang
- Department of Cardiology, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, PR China
| | - Zhuyun Huang
- Department of Cardiology, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, PR China
| | - Jianghua Zhu
- Department of Cardiology, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, PR China
| | - Qing-Hui Chen
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, MI 49931, USA
| | - Le Gui
- Department of Cardiology, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, PR China.
| |
Collapse
|
199
|
Structural perturbations induced by Asn131 and Asn171 glycosylation converge within the EFSAM core and enhance stromal interaction molecule-1 mediated store operated calcium entry. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1864:1054-1063. [PMID: 27865927 DOI: 10.1016/j.bbamcr.2016.11.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 11/11/2016] [Accepted: 11/14/2016] [Indexed: 11/21/2022]
Abstract
A major intracellular calcium (Ca2+) uptake pathway in both excitable and non-excitable eukaryotic cells is store-operated Ca2+ entry (SOCE). SOCE is the process by which endoplasmic reticulum (ER)-stored Ca2+ depletion leads to activation of plasma membrane Ca2+ channels to provide a sustained increase in cytosolic Ca2+ levels that mediate a plethora of physiological processes ranging from the immune response to platelet aggregation. Stromal interaction molecule-1 (STIM1) is the principal regulator of SOCE and responds to changes in ER stored Ca2+ through luminal sensing machinery composed of EF-hand and SAM domains (EFSAM). The EFSAM domain can undergo N-glycosylation at Asn131 and Asn171 sites; however, the precise role of EFSAM N-glycosylation in the Ca2+ sensing mechanism of STIM1 is unclear. By establishing a site-specific chemical approach to covalently linking glucose to EFSAM and examining α-helicity, thermal stability, three dimensional atomic-resolution structure, Ca2+ binding affinity and oligomerization, we show that N-glycosylation of the EFSAM domain enhances the properties that promote STIM1 activation. This augmentation occurs through changes in structure localized near the Asn131 and Asn171 sites that together permeate through the protein core and lead to decreased Ca2+ binding affinity, reduced stability and enhanced oligomerization. Congruently, Ca2+ influx via SOCE in HEK293 cells co-expressing Orai1 and STIM1 was diminished when N-glycosylation was blocked by introducing Asn131Gln and Asn171Gln mutations. Collectively, our data suggests that N-glycosylation enhances the EFSAM destabilization-coupled oligomerization in response to ER Ca2+ depletion thereby augmenting the role of STIM1 as a robust ON/OFF regulator of SOCE. This article is part of a Special Issue entitled: ECS Meeting edited by Claus Heizmann, Joachim Krebs and Jacques Haiech.
Collapse
|
200
|
Poteser M, Leitinger G, Pritz E, Platzer D, Frischauf I, Romanin C, Groschner K. Live-cell imaging of ER-PM contact architecture by a novel TIRFM approach reveals extension of junctions in response to store-operated Ca 2+-entry. Sci Rep 2016; 6:35656. [PMID: 27759093 PMCID: PMC5069484 DOI: 10.1038/srep35656] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 09/29/2016] [Indexed: 01/16/2023] Open
Abstract
Nanometer-spaced appositions between endoplasmic reticulum and plasma membrane (ER-PM junctions) stabilized by membrane-joining protein complexes are critically involved in cellular Ca2+-handling and lipid trafficking. ER-PM junctional architecture and plasticity associated with inter-membrane communication are as yet barely understood. Here, we introduce a method to precisely characterize ER-PM junction morphology and dynamics with high temporal resolution and minimal disturbance of junctional intermembrane communication. We show that expression of soluble cytosolic fluorophores in combination with TIRFM enables to delineate ER and PM distance in the range of 10-150 nm. Live-cell imaging of sub-plasmalemmal structures in RBL-2H3 mast cells by this method, designated as fluorescence density mapping (FDM), revealed profound dynamics of ER-PM contact sites in response to store-depletion. We report the existence of a Ca2+-dependent process that expands the junctional ER to enlarge its contact surface with the PM, thereby promoting and stabilizing STIM1-Orai1 competent ER-PM junctions.
Collapse
Affiliation(s)
- Michael Poteser
- Institute of Biophysics, Medical University of Graz, Harrachgasse 21/4, 8010 Graz, Austria
| | - Gerd Leitinger
- Institute of Cell Biology, Histology and Embryology Research Unit "Electron Microscopic Techniques", Medical University of Graz, Harrachgasse 21/7, 8010 Graz, Austria
| | - Elisabeth Pritz
- Institute of Cell Biology, Histology and Embryology Research Unit "Electron Microscopic Techniques", Medical University of Graz, Harrachgasse 21/7, 8010 Graz, Austria
| | - Dieter Platzer
- Institute of Biophysics, Medical University of Graz, Harrachgasse 21/4, 8010 Graz, Austria
| | - Irene Frischauf
- Institute of Biophysics, Johannes Kepler University of Linz, Austria, Gruberstrasse 40, 4020 Linz, Austria
| | - Christoph Romanin
- Institute of Biophysics, Johannes Kepler University of Linz, Austria, Gruberstrasse 40, 4020 Linz, Austria
| | - Klaus Groschner
- Institute of Biophysics, Medical University of Graz, Harrachgasse 21/4, 8010 Graz, Austria
| |
Collapse
|