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Fröhlich M, Söllner J, Derler I. Insights into the dynamics of the Ca2+ release-activated Ca2+ channel pore-forming complex Orai1. Biochem Soc Trans 2024; 52:747-760. [PMID: 38526208 DOI: 10.1042/bst20230815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/28/2024] [Accepted: 03/04/2024] [Indexed: 03/26/2024]
Abstract
An important calcium (Ca2+) entry pathway into the cell is the Ca2+ release-activated Ca2+ (CRAC) channel, which controls a series of downstream signaling events such as gene transcription, secretion and proliferation. It is composed of a Ca2+ sensor in the endoplasmic reticulum (ER), the stromal interaction molecule (STIM), and the Ca2+ ion channel Orai in the plasma membrane (PM). Their activation is initiated by receptor-ligand binding at the PM, which triggers a signaling cascade within the cell that ultimately causes store depletion. The decrease in ER-luminal Ca2+ is sensed by STIM1, which undergoes structural rearrangements that lead to coupling with Orai1 and its activation. In this review, we highlight the current understanding of the Orai1 pore opening mechanism. In this context, we also point out the questions that remain unanswered and how these can be addressed by the currently emerging genetic code expansion (GCE) technology. GCE enables the incorporation of non-canonical amino acids with novel properties, such as light-sensitivity, and has the potential to provide novel insights into the structure/function relationship of CRAC channels at a single amino acid level in the living cell.
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Affiliation(s)
- Maximilian Fröhlich
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, A-4020 Linz, Austria
| | - Julia Söllner
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, A-4020 Linz, Austria
| | - Isabella Derler
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, A-4020 Linz, Austria
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2
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Jusztus V, Medyouni G, Bagosi A, Lampé R, Panyi G, Matolay O, Maka E, Krasznai ZT, Vörös O, Hajdu P. Activity of Potassium Channels in CD8 + T Lymphocytes: Diagnostic and Prognostic Biomarker in Ovarian Cancer? Int J Mol Sci 2024; 25:1949. [PMID: 38396628 PMCID: PMC10888402 DOI: 10.3390/ijms25041949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/31/2024] [Accepted: 02/03/2024] [Indexed: 02/25/2024] Open
Abstract
CD8+ T cells play a role in the suppression of tumor growth and immunotherapy. Ion channels control the Ca2+-dependent function of CD8+ lymphocytes such as cytokine/granzyme production and tumor killing. Kv1.3 and KCa3.1 K+ channels stabilize the negative membrane potential of T cells to maintain Ca2+ influx through CRAC channels. We assessed the expression of Kv1.3, KCa3.1 and CRAC in CD8+ cells from ovarian cancer (OC) patients (n = 7). We found that the expression level of Kv1.3 was higher in patients with malignant tumors than in control or benign tumor groups while the KCa3.1 activity was lower in the malignant tumor group as compared to the others. We demonstrated that the Ca2+ response in malignant tumor patients is higher compared to control groups. We propose that altered Kv1.3 and KCa3.1 expression in CD8+ cells in OC could be a reporter and may serve as a biomarker in diagnostics and that increased Ca2+ response through CRAC may contribute to the impaired CD8+ function.
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Affiliation(s)
- Vivien Jusztus
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem tér 1., H-4032 Debrecen, Hungary; (V.J.); (G.M.); (A.B.); (G.P.); (O.V.)
| | - Ghofrane Medyouni
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem tér 1., H-4032 Debrecen, Hungary; (V.J.); (G.M.); (A.B.); (G.P.); (O.V.)
| | - Adrienn Bagosi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem tér 1., H-4032 Debrecen, Hungary; (V.J.); (G.M.); (A.B.); (G.P.); (O.V.)
| | - Rudolf Lampé
- Department of Gynecology and Obstetrics, Faculty of Medicine, University of Debrecen, Egyetem tér 1., H-4032 Debrecen, Hungary; (R.L.); (O.M.); (E.M.); (Z.T.K.)
| | - György Panyi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem tér 1., H-4032 Debrecen, Hungary; (V.J.); (G.M.); (A.B.); (G.P.); (O.V.)
| | - Orsolya Matolay
- Department of Gynecology and Obstetrics, Faculty of Medicine, University of Debrecen, Egyetem tér 1., H-4032 Debrecen, Hungary; (R.L.); (O.M.); (E.M.); (Z.T.K.)
| | - Eszter Maka
- Department of Gynecology and Obstetrics, Faculty of Medicine, University of Debrecen, Egyetem tér 1., H-4032 Debrecen, Hungary; (R.L.); (O.M.); (E.M.); (Z.T.K.)
| | - Zoárd Tibor Krasznai
- Department of Gynecology and Obstetrics, Faculty of Medicine, University of Debrecen, Egyetem tér 1., H-4032 Debrecen, Hungary; (R.L.); (O.M.); (E.M.); (Z.T.K.)
| | - Orsolya Vörös
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem tér 1., H-4032 Debrecen, Hungary; (V.J.); (G.M.); (A.B.); (G.P.); (O.V.)
| | - Péter Hajdu
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem tér 1., H-4032 Debrecen, Hungary; (V.J.); (G.M.); (A.B.); (G.P.); (O.V.)
- Division of Dental Biochemistry, Department of Basic Medical Sciences, Faculty of Dentistry, University of Debrecen, Egyetem tér 1., H-4032 Debrecen, Hungary
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3
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Kong X, Wang F, Chen Y, Liang X, Yin Y, Liu H, Luo G, Li Y, Liang S, Wang Y, Liu Z, Tang C. Molecular action mechanisms of two novel and selective calcium release-activated calcium channel antagonists. Int J Biol Macromol 2023; 253:126937. [PMID: 37722647 DOI: 10.1016/j.ijbiomac.2023.126937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 09/11/2023] [Accepted: 09/15/2023] [Indexed: 09/20/2023]
Abstract
The prototypical calcium release-activated calcium (CRAC) channel, composed of STIM1 and Orai1, is a sought-after drug target for treating autoimmune disorders. Herein, we identified two novel and selective CRAC channel inhibitors, the indole-like compound C63368 and pyrazole core-containing compound C79413, potently and reversibly inhibiting the CRAC channel with low micromolar IC50s and sparing various off-target ion channels. These two compounds did not inhibit STIM1 activation or its coupling with Orai1, nor did they affect the channel's calcium-dependent fast inactivation. Instead, they directly acted on the Orai1 protein, with the channel's pore geometry profoundly affecting their potencies. In vitro, C63368 and C79413 effectively inhibited Jurkat cell proliferation and cytokines production in human T lymphocytes. Intragastric administration of C63368 and C79413 to mice yielded great therapeutic benefits in psoriasis and colitis animal models of autoimmune disorders, reducing serum cytokines production and significantly relieving pathological symptoms. It's worth noting, that this study provided the first insight into the characterization and mechanistic investigation of an indole-like CRAC channel antagonist. Altogether, the identification of these two highly selective CRAC channel antagonists, coupled with the elucidation of their action mechanisms, not only provides valuable template molecules but also offers profound insights for drug development targeting the CRAC channel.
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Affiliation(s)
- Xiangjin Kong
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410081, China; Peptide and Small Molecule Drug R&D Platform, Furong Laboratory, Changsha 40081, China
| | - Feifan Wang
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing 100875, China
| | - Yan Chen
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Xinyao Liang
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Yuan Yin
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Hao Liu
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Guoqing Luo
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Yinping Li
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Songping Liang
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Youjun Wang
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing 100875, China; Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing 100875, China.
| | - Zhonghua Liu
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410081, China; Peptide and Small Molecule Drug R&D Platform, Furong Laboratory, Changsha 40081, China.
| | - Cheng Tang
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410081, China; Peptide and Small Molecule Drug R&D Platform, Furong Laboratory, Changsha 40081, China.
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Cohen HA, Zomot E, Nataniel T, Militsin R, Palty R. The SOAR of STIM1 interacts with plasma membrane lipids to form ER-PM contact sites. Cell Rep 2023; 42:112238. [PMID: 36906853 DOI: 10.1016/j.celrep.2023.112238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 01/15/2023] [Accepted: 02/23/2023] [Indexed: 03/12/2023] Open
Abstract
Depletion of Ca2+ from the endoplasmic reticulum (ER) causes the ER Ca2+ sensor STIM1 to form membrane contact sites (MCSs) with the plasma membrane (PM). At the ER-PM MCS, STIM1 binds to Orai channels to induce cellular Ca2+ entry. The prevailing view of this sequential process is that STIM1 interacts with the PM and with Orai1 using two separate modules: a C-terminal polybasic domain (PBD) for the interaction with PM phosphoinositides and the STIM-Orai activation region (SOAR) for the interaction with Orai channels. Here, using electron and fluorescence microscopy and protein-lipid interaction assays, we show that oligomerization of the SOAR promotes direct interaction with PM phosphoinositides to trap STIM1 at ER-PM MCSs. The interaction depends on a cluster of conserved lysine residues within the SOAR and is co-regulated by the STIM1 coil-coiled 1 and inactivation domains. Collectively, our findings uncover a molecular mechanism for formation and regulation of ER-PM MCSs by STIM1.
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Affiliation(s)
- Hadas Achildiev Cohen
- Department of Biochemistry, Technion Integrated Cancer Center, Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa 31096, Israel
| | - Elia Zomot
- Department of Biochemistry, Technion Integrated Cancer Center, Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa 31096, Israel
| | - Tomer Nataniel
- Department of Biochemistry, Technion Integrated Cancer Center, Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa 31096, Israel
| | - Ruslana Militsin
- Department of Biochemistry, Technion Integrated Cancer Center, Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa 31096, Israel
| | - Raz Palty
- Department of Biochemistry, Technion Integrated Cancer Center, Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa 31096, Israel.
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5
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Das C, Vijayan MM. Cortisol Rapidly Facilitates Glucocorticoid Receptor Translocation to the Plasma Membrane in Primary Trout Hepatocytes. Biology (Basel) 2023; 12. [PMID: 36829586 DOI: 10.3390/biology12020311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 02/07/2023] [Accepted: 02/10/2023] [Indexed: 02/17/2023]
Abstract
Glucocorticoids (GCs) stimulate rapid cell signalling by activating the membrane-anchored intracellular glucocorticoid receptor (GR). However, the recruitment of the GR to the plasma membrane to facilitate nongenomic signalling is far from clear. As cytosolic free calcium ([Ca2+]i) is involved in intracellular protein dynamics, we tested the hypothesis that acute elevation in cortisol levels rapidly stimulates GR translocation to the plasma membrane via a calcium-dependent process in rainbow trout (Oncorhynchus mykiss) hepatocytes. To test this, we monitored temporal changes in intracellular GR distribution in response to cortisol exposure. Immunofluorescence labelling showed that the GR was present in cytosolic and nuclear compartments in trout hepatocytes. However, upon cortisol exposure, the GR rapidly (within 5 min) formed punctate and colocalized with caveolin-1, suggesting plasma membrane localization of the receptor. This redistribution of the GR to the plasma membrane was transient and lasted for 30 min and was evident even upon exposure to cortisol-BSA, a membrane-impermeable analogue of the steroid. The rapid cortisol-mediated GR translocation to the plasma membrane involved F-actin polymerization and was completely abolished in the presence of either EGTA or Cpd5J-4, a calcium release-activated calcium (CRAC) channel blocker. Additionally, the modulation of the biophysical properties of the plasma membrane by cholesterol or methyl β-cyclodextrin, which led to changes in ([Ca2+]i) levels, modified GR translocation to the plasma membrane. Altogether, acute cortisol-mediated rise in ([Ca2+]i) levels rapidly stimulated the translocation of intracellular GR to the plasma membrane, and we propose this as a mechanism promoting the nongenomic action of the GR for hepatocyte stress resistance.
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Yuan X, Tang B, Chen Y, Zhou L, Deng J, Han L, Zhai Y, Zhou Y, Gill DL, Lu C, Wang Y. Celastrol inhibits store operated calcium entry and suppresses psoriasis. Front Pharmacol 2023; 14:1111798. [PMID: 36817139 PMCID: PMC9928759 DOI: 10.3389/fphar.2023.1111798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 01/20/2023] [Indexed: 02/05/2023] Open
Abstract
Introduction: Psoriasis is an inflammatory autoimmune skin disease that is hard to cure and prone to relapse. Currently available global immunosuppressive agents for psoriasis may cause severe side effects, thus it is crucial to identify new therapeutic reagents and druggable signaling pathways for psoriasis. Methods: To check the effects of SOCE inhibitors on psoriasis, we used animal models, biochemical approaches, together with various imaging techniques, including calcium, confocal and FRET imaging. Results and discussion: Store operated calcium (Ca2+) entry (SOCE), mediated by STIM1 and Orai1, is crucial for the function of keratinocytes and immune cells, the two major players in psoriasis. Here we showed that a natural compound celastrol is a novel SOCE inhibitor, and it ameliorated the skin lesion and reduced PASI scores in imiquimod-induced psoriasis-like mice. Celastrol dose- and time-dependently inhibited SOCE in HEK cells and HaCaT cells, a keratinocyte cell line. Mechanistically, celastrol inhibited SOCE via its actions both on STIM1 and Orai1. It inhibited Ca2+ entry through constitutively-active Orai1 mutants independent of STIM1. Rather than blocking the conformational switch and oligomerization of STIM1 during SOCE activation, celastrol diminished the transition from oligomerized STIM1 into aggregates, thus locking STIM1 in a partially active state. As a result, it abolished the functional coupling between STIM1 and Orai1, diminishing SOCE signals. Overall, our findings identified a new SOCE inhibitor celastrol that suppresses psoriasis, suggesting that SOCE pathway may serve as a new druggable target for treating psoriasis.
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Affiliation(s)
- Xiaoman Yuan
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Bin Tang
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Clinical College of Guangzhou University of Chinese Medicine, Guangzhou, China,Guangdong-Hong Kong-Macau Joint Lab on Chinese Medicine and Immune Disease Research, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Yilan Chen
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Lijuan Zhou
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Jingwen Deng
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Clinical College of Guangzhou University of Chinese Medicine, Guangzhou, China,Guangdong-Hong Kong-Macau Joint Lab on Chinese Medicine and Immune Disease Research, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Lin Han
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Clinical College of Guangzhou University of Chinese Medicine, Guangzhou, China,Guangdong-Hong Kong-Macau Joint Lab on Chinese Medicine and Immune Disease Research, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Yonggong Zhai
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Yandong Zhou
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Donald L. Gill
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Chuanjian Lu
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Clinical College of Guangzhou University of Chinese Medicine, Guangzhou, China,Guangdong-Hong Kong-Macau Joint Lab on Chinese Medicine and Immune Disease Research, Guangzhou University of Chinese Medicine, Guangzhou, China,*Correspondence: Youjun Wang, ; Chuanjian Lu,
| | - Youjun Wang
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing, China,Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, China,*Correspondence: Youjun Wang, ; Chuanjian Lu,
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7
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Tiffner A, Hopl V, Derler I. CRAC and SK Channels: Their Molecular Mechanisms Associated with Cancer Cell Development. Cancers (Basel) 2022; 15:cancers15010101. [PMID: 36612099 PMCID: PMC9817886 DOI: 10.3390/cancers15010101] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/16/2022] [Accepted: 12/19/2022] [Indexed: 12/28/2022] Open
Abstract
Cancer represents a major health burden worldwide. Several molecular targets have been discovered alongside treatments with positive clinical outcomes. However, the reoccurrence of cancer due to therapy resistance remains the primary cause of mortality. Endeavors in pinpointing new markers as molecular targets in cancer therapy are highly desired. The significance of the co-regulation of Ca2+-permeating and Ca2+-regulated ion channels in cancer cell development, proliferation, and migration make them promising molecular targets in cancer therapy. In particular, the co-regulation of the Orai1 and SK3 channels has been well-studied in breast and colon cancer cells, where it finally leads to an invasion-metastasis cascade. Nevertheless, many questions remain unanswered, such as which key molecular components determine and regulate their interplay. To provide a solid foundation for a better understanding of this ion channel co-regulation in cancer, we first shed light on the physiological role of Ca2+ and how this ion is linked to carcinogenesis. Then, we highlight the structure/function relationship of Orai1 and SK3, both individually and in concert, their role in the development of different types of cancer, and aspects that are not yet known in this context.
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Udasin R, Sil A, Zomot E, Achildiev Cohen H, Haj J, Engelmayer N, Lev S, Binshtok AM, Shaked Y, Kienzler MA, Palty R. Photopharmacological modulation of native CRAC channels using azoboronate photoswitches. Proc Natl Acad Sci U S A 2022; 119:e2118160119. [PMID: 35312368 DOI: 10.1073/pnas.2118160119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Calcium release–activated calcium (CRAC) channels play key roles in the regulation of cellular signaling, transcription, and migration. Here, we describe the design, chemical synthesis, and characterization of photoswitchable channel inhibitors that can be switched on and off depending on the wavelength of light used. We use the compounds to induce light-dependent modulation of channel activity and downstream gene expression in human immune cells. We further expand the usage of the compounds to control seeding of cancer cells in target tissue and regulation of response to noxious stimuli in vivo in mice. Store-operated calcium entry through calcium release–activated calcium (CRAC) channels replenishes intracellular calcium stores and plays a critical role in cellular calcium signaling. CRAC channels are activated by tightly regulated interaction between the endoplasmic reticulum (ER) calcium sensor STIM proteins and plasma membrane (PM) Orai channels. Our current understanding of the role of STIM–Orai-dependent calcium signals under physiologically relevant conditions remains limited in part due to a lack of spatiotemporally precise methods for direct manipulation of endogenous CRAC channels. Here, we report the synthesis and characterization of azoboronate light-operated CRAC channel inhibitors (LOCIs) that allow for a dynamic and fully reversible remote modulation of the function of native CRAC channels using ultraviolet (UV) and visible light. We demonstrate the use of LOCI-1 to modulate gene expression in T lymphocytes, cancer cell seeding at metastatic sites, and pain-related behavior.
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Palty R. CRACR2A associated immunodeficiency - the supporting factor takes center stage. Cell Calcium 2022; 103:102552. [PMID: 35151051 DOI: 10.1016/j.ceca.2022.102552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/03/2022] [Accepted: 02/04/2022] [Indexed: 11/30/2022]
Abstract
Loss of function mutations in one of the core components of the calcium release-activated calcium (CRAC) channel complex, STIM1 and ORAI1, lead to severe immunodeficiency. Whether changes in regulatory components of the CRAC channel may also contribute to a disease state remained unknown. In a recent study, Wu et al. report a case of late onset immunodeficiency in a patient with bi-allelic mutation in CRACR2A, a regulatory component of the CRAC channel.
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Affiliation(s)
- Raz Palty
- Department of Biochemistry, Technion Integrated Cancer Center, Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa 31096 Israel.
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10
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Humer C, Romanin C, Höglinger C. Highlighting the Multifaceted Role of Orai1 N-Terminal- and Loop Regions for Proper CRAC Channel Functions. Cells 2022; 11:371. [PMID: 35159181 PMCID: PMC8834118 DOI: 10.3390/cells11030371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/14/2022] [Accepted: 01/15/2022] [Indexed: 11/16/2022] Open
Abstract
Orai1, the Ca2+-selective pore in the plasma membrane, is one of the key components of the Ca2+release-activated Ca2+ (CRAC) channel complex. Activated by the Ca2+ sensor in the endoplasmic reticulum (ER) membrane, stromal interaction molecule 1 (STIM1), via direct interaction when ER luminal Ca2+ levels recede, Orai1 helps to maintain Ca2+ homeostasis within a cell. It has already been proven that the C-terminus of Orai1 is indispensable for channel activation. However, there is strong evidence that for CRAC channels to function properly and maintain all typical hallmarks, such as selectivity and reversal potential, additional parts of Orai1 are needed. In this review, we focus on these sites apart from the C-terminus; namely, the second loop and N-terminus of Orai1 and on their multifaceted role in the functioning of CRAC channels.
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Affiliation(s)
| | | | - Carmen Höglinger
- Institute of Biophysics, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria; (C.H.); (C.R.)
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Mokrane N, Snabi Y, Cens T, Guiramand J, Charnet P, Bertaud A, Menard C, Rousset M, de Jesus Ferreira MC, Thibaud JB, Cohen-Solal C, Vignes M, Roussel J. Manipulations of Glutathione Metabolism Modulate IP 3-Mediated Store-Operated Ca 2+ Entry on Astroglioma Cell Line. Front Aging Neurosci 2022; 13:785727. [PMID: 34975458 PMCID: PMC8719003 DOI: 10.3389/fnagi.2021.785727] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 12/01/2021] [Indexed: 02/03/2023] Open
Abstract
The regulation of the redox status involves the activation of intracellular pathways as Nrf2 which provides hormetic adaptations against oxidative stress in response to environmental stimuli. In the brain, Nrf2 activation upregulates the formation of glutathione (GSH) which is the primary antioxidant system mainly produced by astrocytes. Astrocytes have also been shown to be themselves the target of oxidative stress. However, how changes in the redox status itself could impact the intracellular Ca2+ homeostasis in astrocytes is not known, although this could be of great help to understand the neuronal damage caused by oxidative stress. Indeed, intracellular Ca2+ changes in astrocytes are crucial for their regulatory actions on neuronal networks. We have manipulated GSH concentration in astroglioma cells with selective inhibitors and activators of the enzymes involved in the GSH cycle and analyzed how this could modify Ca2+ homeostasis. IP3-mediated store-operated calcium entry (SOCE), obtained after store depletion elicited by Gq-linked purinergic P2Y receptors activation, are either sensitized or desensitized, following GSH depletion or increase, respectively. The desensitization may involve decreased expression of the proteins STIM2, Orai1, and Orai3 which support SOCE mechanism. The sensitization process revealed by exposing cells to oxidative stress likely involves the increase in the activity of Calcium Release-Activated Channels (CRAC) and/or in their membrane expression. In addition, we observe that GSH depletion drastically impacts P2Y receptor-mediated changes in membrane currents, as evidenced by large increases in Ca2+-dependent K+ currents. We conclude that changes in the redox status of astrocytes could dramatically modify Ca2+ responses to Gq-linked GPCR activation in both directions, by impacting store-dependent Ca2+-channels, and thus modify cellular excitability under purinergic stimulation.
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Affiliation(s)
- Nawfel Mokrane
- UMR 5247 Institut des Biomolécules Max Mousseron (IBMM), Montpellier, France.,Department of Biological Sciences, Université de Montpellier, Montpellier, France
| | - Yassin Snabi
- UMR 5247 Institut des Biomolécules Max Mousseron (IBMM), Montpellier, France.,Department of Biological Sciences, Université de Montpellier, Montpellier, France
| | - Thierry Cens
- UMR 5247 Institut des Biomolécules Max Mousseron (IBMM), Montpellier, France
| | - Janique Guiramand
- UMR 5247 Institut des Biomolécules Max Mousseron (IBMM), Montpellier, France
| | - Pierre Charnet
- UMR 5247 Institut des Biomolécules Max Mousseron (IBMM), Montpellier, France
| | - Anaïs Bertaud
- UMR 5247 Institut des Biomolécules Max Mousseron (IBMM), Montpellier, France.,Department of Biological Sciences, Université de Montpellier, Montpellier, France
| | - Claudine Menard
- UMR 5247 Institut des Biomolécules Max Mousseron (IBMM), Montpellier, France.,Department of Biological Sciences, Université de Montpellier, Montpellier, France
| | - Matthieu Rousset
- UMR 5247 Institut des Biomolécules Max Mousseron (IBMM), Montpellier, France
| | - Marie-Céleste de Jesus Ferreira
- UMR 5247 Institut des Biomolécules Max Mousseron (IBMM), Montpellier, France.,Department of Biological Sciences, Université de Montpellier, Montpellier, France
| | | | - Catherine Cohen-Solal
- UMR 5247 Institut des Biomolécules Max Mousseron (IBMM), Montpellier, France.,Department of Biological Sciences, Université de Montpellier, Montpellier, France
| | - Michel Vignes
- UMR 5247 Institut des Biomolécules Max Mousseron (IBMM), Montpellier, France.,Department of Biological Sciences, Université de Montpellier, Montpellier, France
| | - Julien Roussel
- UMR 5247 Institut des Biomolécules Max Mousseron (IBMM), Montpellier, France.,Department of Biological Sciences, Université de Montpellier, Montpellier, France
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12
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Fresquez AM, White C. Extracellular cysteines C226 and C232 mediate hydrogen sulfide-dependent inhibition of Orai3-mediated store-operated calcium entry. Am J Physiol Cell Physiol 2022; 322:C38-C48. [PMID: 34788146 PMCID: PMC8759961 DOI: 10.1152/ajpcell.00490.2019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The gaseous signaling molecule hydrogen sulfide (H2S) physiologically regulates store-operated Ca2+ entry (SOCE). The SOCE machinery consists of the plasma membrane-localized Orai channels (Orai1-3) and endoplasmic reticulum-localized stromal interaction molecule (STIM)1 and STIM2 proteins. H2S inhibits Orai3- but not Orai1- or Orai2-mediated SOCE. The current objective was to define the mechanism by which H2S selectively modifies Orai3. We measured SOCE and STIM1/Orai3 dynamics and interactions in HEK293 cells exogenously expressing fluorescently tagged human STIM1 and Orai3 in the presence and absence of the H2S donor GYY4137. Two cysteines (C226 and C232) are present in Orai3 that are absent in the Orai1 and Orai2. When we mutated either of these cysteines to serine, alone or in combination, SOCE inhibition by H2S was abolished. We also established that inhibition was dependent on an interaction with STIM1. To further define the effects of H2S on STIM1/Orai3 interaction, we performed a series of fluorescence recovery after photobleaching (FRAP), colocalization, and fluorescence resonance energy transfer (FRET) experiments. Treatment with H2S did not affect the mobility of Orai3 in the membrane, nor did it influence STIM1/Orai3 puncta formation or STIM1-Orai3 protein-protein interactions. These data support a model in which H2S modification of Orai3 at cysteines 226 and 232 limits SOCE evoked upon store depletion and STIM1 engagement, by a mechanism independent of the interaction between Orai3 and STIM1.
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Affiliation(s)
- Adriana M. Fresquez
- 1Discipline of Physiology and Biophysics, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois,2Center for Cancer Cell Biology, Immunology, and Infection, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois
| | - Carl White
- 1Discipline of Physiology and Biophysics, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois,2Center for Cancer Cell Biology, Immunology, and Infection, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois
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13
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Tiffner A, Hopl V, Schober R, Sallinger M, Grabmayr H, Höglinger C, Fahrner M, Lunz V, Maltan L, Frischauf I, Krivic D, Bhardwaj R, Schindl R, Hediger MA, Derler I. Orai1 Boosts SK3 Channel Activation. Cancers (Basel) 2021; 13:6357. [PMID: 34944977 PMCID: PMC8699475 DOI: 10.3390/cancers13246357] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 12/13/2021] [Indexed: 12/20/2022] Open
Abstract
The interplay of SK3, a Ca2+ sensitive K+ ion channel, with Orai1, a Ca2+ ion channel, has been reported to increase cytosolic Ca2+ levels, thereby triggering proliferation of breast and colon cancer cells, although a molecular mechanism has remained elusive to date. We show in the current study, via heterologous protein expression, that Orai1 can enhance SK3 K+ currents, in addition to constitutively bound calmodulin (CaM). At low cytosolic Ca2+ levels that decrease SK3 K+ permeation, co-expressed Orai1 potentiates SK3 currents. This positive feedback mechanism of SK3 and Orai1 is enabled by their close co-localization. Remarkably, we discovered that loss of SK3 channel activity due to overexpressed CaM mutants could be restored by Orai1, likely via its interplay with the SK3-CaM binding site. Mapping for interaction sites within Orai1, we identified that the cytosolic strands and pore residues are critical for a functional communication with SK3. Moreover, STIM1 has a bimodal role in SK3-Orai1 regulation. Under physiological ionic conditions, STIM1 is able to impede SK3-Orai1 interplay by significantly decreasing their co-localization. Forced STIM1-Orai1 activity and associated Ca2+ influx promote SK3 K+ currents. The dynamic regulation of Orai1 to boost endogenous SK3 channels was also determined in the human prostate cancer cell line LNCaP.
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Affiliation(s)
- Adéla Tiffner
- JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (V.H.); (R.S.); (M.S.); (H.G.); (C.H.); (M.F.); (V.L.); (L.M.); (I.F.)
| | - Valentina Hopl
- JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (V.H.); (R.S.); (M.S.); (H.G.); (C.H.); (M.F.); (V.L.); (L.M.); (I.F.)
| | - Romana Schober
- JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (V.H.); (R.S.); (M.S.); (H.G.); (C.H.); (M.F.); (V.L.); (L.M.); (I.F.)
- Gottfried Schatz Research Centre, Medical University of Graz, A-8010 Graz, Austria; (D.K.); (R.S.)
| | - Matthias Sallinger
- JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (V.H.); (R.S.); (M.S.); (H.G.); (C.H.); (M.F.); (V.L.); (L.M.); (I.F.)
| | - Herwig Grabmayr
- JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (V.H.); (R.S.); (M.S.); (H.G.); (C.H.); (M.F.); (V.L.); (L.M.); (I.F.)
| | - Carmen Höglinger
- JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (V.H.); (R.S.); (M.S.); (H.G.); (C.H.); (M.F.); (V.L.); (L.M.); (I.F.)
| | - Marc Fahrner
- JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (V.H.); (R.S.); (M.S.); (H.G.); (C.H.); (M.F.); (V.L.); (L.M.); (I.F.)
| | - Victoria Lunz
- JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (V.H.); (R.S.); (M.S.); (H.G.); (C.H.); (M.F.); (V.L.); (L.M.); (I.F.)
| | - Lena Maltan
- JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (V.H.); (R.S.); (M.S.); (H.G.); (C.H.); (M.F.); (V.L.); (L.M.); (I.F.)
| | - Irene Frischauf
- JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (V.H.); (R.S.); (M.S.); (H.G.); (C.H.); (M.F.); (V.L.); (L.M.); (I.F.)
| | - Denis Krivic
- Gottfried Schatz Research Centre, Medical University of Graz, A-8010 Graz, Austria; (D.K.); (R.S.)
| | - Rajesh Bhardwaj
- Department of Nephrology and Hypertension, University of Bern, Inselspital, Freiburgstrasse 15, CH-3010 Bern, Switzerland; (R.B.); (M.A.H.)
- Department of Biomedical Research, University of Bern, Inselspital, Freiburgstrasse 15, CH-3010 Bern, Switzerland
| | - Rainer Schindl
- Gottfried Schatz Research Centre, Medical University of Graz, A-8010 Graz, Austria; (D.K.); (R.S.)
| | - Matthias A. Hediger
- Department of Nephrology and Hypertension, University of Bern, Inselspital, Freiburgstrasse 15, CH-3010 Bern, Switzerland; (R.B.); (M.A.H.)
- Department of Biomedical Research, University of Bern, Inselspital, Freiburgstrasse 15, CH-3010 Bern, Switzerland
| | - Isabella Derler
- JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (V.H.); (R.S.); (M.S.); (H.G.); (C.H.); (M.F.); (V.L.); (L.M.); (I.F.)
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14
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Abstract
CRAC channel is ubiquitous and its importance in the regulation of the immune system is testified by the severe immunodeficiencies caused by its mutations. In this work we took advantage of the availability of open and closed structures of this channel to run for the first time simulations of the whole gating process reaching the relevant time-scale with an enhanced sampling technique, Targeted Molecular Dynamics. Our simulations highlighted a complex allosteric propagation of the conformational change from peripheral helices, where the activator STIM1 binds, to the central pore helices. In agreement with mutagenesis data, our simulations revealed the key role of residue H206 whose displacement creates an empty space behind the hydrophobic region of the pore, thus releasing a steric brake and allowing the opening of the channel. Conversely, the process of pore closing culminates with the formation of a bubble that occludes the pore even in the absence of steric block. This mechanism, known as "hydrophobic gating", has been observed in an increasing number of biological ion channels and also in artificial nanopores. Our study therefore shows promise not only to better understand the molecular origin of diseases caused by disrupted calcium signaling, but also to clarify the mode of action of hydrophobically gated ion channels, possibly even suggesting strategies for the biomimetic design of synthetic nanopores.
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Affiliation(s)
| | | | - Alberto Giacomello
- Dipartimento di Ingegneria Meccanica e Aerospaziale, Sapienza Università di Roma, Rome, Italy
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15
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Grieve AG, Yeh YC, Chang YF, Huang HY, Zarcone L, Breuning J, Johnson N, Stříšovský K, Brown MH, Parekh AB, Freeman M. Conformational surveillance of Orai1 by a rhomboid intramembrane protease prevents inappropriate CRAC channel activation. Mol Cell 2021; 81:4784-4798.e7. [PMID: 34800360 DOI: 10.1016/j.molcel.2021.10.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/14/2021] [Accepted: 10/26/2021] [Indexed: 12/19/2022]
Abstract
Calcium influx through plasma membrane calcium release-activated calcium (CRAC) channels, which are formed of hexamers of Orai1, is a potent trigger for many important biological processes, most notably in T cell-mediated immunity. Through a bioinformatics-led cell biological screen, we have identified Orai1 as a substrate for the rhomboid intramembrane protease RHBDL2. We show that RHBDL2 prevents stochastic calcium signaling in unstimulated cells through conformational surveillance and cleavage of inappropriately activated Orai1. A conserved disease-linked proline residue is responsible for RHBDL2’s recognizing the active conformation of Orai1, which is required to sharpen switch-like signaling triggered by store-operated calcium entry. Loss of RHBDL2 control of CRAC channel activity causes severe dysregulation of downstream CRAC channel effectors, including transcription factor activation, inflammatory cytokine expression, and T cell activation. We propose that this surveillance function may represent an ancient activity of rhomboid proteases in degrading unwanted signaling proteins. A screen for transmembrane substrates of the rhomboid intramembrane protease RHBDL2 RHBDL2 cleaves the CRAC channel protein Orai1 when it is inappropriately activated Conformational change in these calcium channels is recognized by RHBDL2 An Orai1 mutant that cannot be cleaved by RHBDL2 causes a human disease syndrome
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16
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Maltan L, Najjar H, Tiffner A, Derler I. Deciphering Molecular Mechanisms and Intervening in Physiological and Pathophysiological Processes of Ca 2+ Signaling Mechanisms Using Optogenetic Tools. Cells 2021; 10:3340. [PMID: 34943850 PMCID: PMC8699489 DOI: 10.3390/cells10123340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/17/2021] [Accepted: 11/22/2021] [Indexed: 11/16/2022] Open
Abstract
Calcium ion channels are involved in numerous biological functions such as lymphocyte activation, muscle contraction, neurotransmission, excitation, hormone secretion, gene expression, cell migration, memory, and aging. Therefore, their dysfunction can lead to a wide range of cellular abnormalities and, subsequently, to diseases. To date various conventional techniques have provided valuable insights into the roles of Ca2+ signaling. However, their limited spatiotemporal resolution and lack of reversibility pose significant obstacles in the detailed understanding of the structure-function relationship of ion channels. These drawbacks could be partially overcome by the use of optogenetics, which allows for the remote and well-defined manipulation of Ca2+-signaling. Here, we review the various optogenetic tools that have been used to achieve precise control over different Ca2+-permeable ion channels and receptors and associated downstream signaling cascades. We highlight the achievements of optogenetics as well as the still-open questions regarding the resolution of ion channel working mechanisms. In addition, we summarize the successes of optogenetics in manipulating many Ca2+-dependent biological processes both in vitro and in vivo. In summary, optogenetics has significantly advanced our understanding of Ca2+ signaling proteins and the used tools provide an essential basis for potential future therapeutic application.
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Affiliation(s)
| | | | | | - Isabella Derler
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, A-4020 Linz, Austria; (L.M.); (H.N.); (A.T.)
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17
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Abstract
Orai channels belong to the calcium release-activated calcium (CRAC) channel family. Orai channels are responsible for the influx of extracellular Ca2+ that is triggered by Ca2+ depletion from the endoplasmic reticulum (ER); this function is essential for many types of non-excitable cells. Extensive structural and functional studies have advanced the knowledge of the molecular mechanism by which Orai channels are activated. However, the gating mechanism that allows Ca2+ permeation through Orai channels is less well explained. Here, we reviewed and summarized the existing structural studies of Orai channels. We detailed the structural features of Orai channels, described structural comparisons of their closed and open states, and finally proposed a "push-pull" model of Ca2+ permeation.
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18
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Abstract
Calcium (Ca2+) signaling plays a dichotomous role in cellular biology, controlling cell survival and proliferation on the one hand and cellular toxicity and cell death on the other. Store-operated Ca2+ entry (SOCE) by CRAC channels represents a major pathway for Ca2+ entry in non-excitable cells. The CRAC channel has two key components, the endoplasmic reticulum Ca2+ sensor stromal interaction molecule (STIM) and the plasma-membrane Ca2+ channel Orai. Physical coupling between STIM and Orai opens the CRAC channel and the resulting Ca2+ flux is regulated by a negative feedback mechanism of slow Ca2+ dependent inactivation (SCDI). The identification of the SOCE-associated regulatory factor (SARAF) and investigations of its role in SCDI have led to new functional and molecular insights into how SOCE is controlled. In this review, we provide an overview of the functional and molecular mechanisms underlying SCDI and discuss how the interaction between SARAF, STIM1, and Orai1 shapes Ca2+ signaling in cells.
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19
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De Moudt S, De Munck D, Coornaert I, Fransen P. GSK-7975A, an inhibitor of Ca 2+ release-activated calcium channels, depresses isometric contraction of mouse aorta. Eur J Pharmacol 2021; 906:174197. [PMID: 34052216 DOI: 10.1016/j.ejphar.2021.174197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 04/28/2021] [Accepted: 05/17/2021] [Indexed: 11/21/2022]
Abstract
GSK-7975A is described to inhibit stromal interaction molecule 1(STIM1)-mediated Ca2+ release-activated Ca2+ channels ORAI 1, ORAI 2 and ORAI 3 in different cell types. The present study investigated whether isometric contractions of mouse aortic segments were affected by this selective store-operated calcium channel inhibitor. Depending on the way by which Ca2+ influx pathways were activated during contraction, GSK-7975A inhibited contractility of mouse aortic segments with different affinity. When contractile effects were induced by depolarization as with elevated extracellular K+ and opening of voltage-gated calcium channels, the affinity was approximately 10 times lower than when contraction was elicited with Ca2+ influx via non-selective cation channels. GSK-7975A may repolarize the aortic smooth muscle cells by inhibiting non-selective cation channels, has no effect on IP3-mediated phenylephrine-induced phasic contractions or on refilling of the contractile sarcoplasmic reticulum Ca2+ store, but has significant effects on non-contractile store-operated Ca2+ influx.
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20
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Tiffner A, Maltan L, Fahrner M, Sallinger M, Weiß S, Grabmayr H, Höglinger C, Derler I. Transmembrane Domain 3 (TM3) Governs Orai1 and Orai3 Pore Opening in an Isoform-Specific Manner. Front Cell Dev Biol 2021; 9:635705. [PMID: 33644073 PMCID: PMC7905104 DOI: 10.3389/fcell.2021.635705] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/21/2021] [Indexed: 12/17/2022] Open
Abstract
STIM1-mediated activation of calcium selective Orai channels is fundamental for life. The three Orai channel isoforms, Orai1-3, together with their multiple ways of interplay, ensure their highly versatile role in a variety of cellular functions and tissues in both, health and disease. While all three isoforms are activated in a store-operated manner by STIM1, they differ in diverse biophysical and structural properties. In the present study, we provide profound evidence that non-conserved residues in TM3 control together with the cytosolic loop2 region the maintenance of the closed state and the configuration of an opening-permissive channel conformation of Orai1 and Orai3 in an isoform-specific manner. Indeed, analogous amino acid substitutions of these non-conserved residues led to distinct extents of gain- (GoF) or loss-of-function (LoF). Moreover, we showed that enhanced overall hydrophobicity along TM3 correlates with an increase in GoF mutant currents. Conclusively, while the overall activation mechanisms of Orai channels appear comparable, there are considerable variations in gating checkpoints crucial for pore opening. The elucidation of regions responsible for isoform-specific functional differences provides valuable targets for drug development selective for one of the three Orai homologs.
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Affiliation(s)
| | | | | | | | | | | | | | - Isabella Derler
- JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, Linz, Austria
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21
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Huo J, Dong H. Gating and regulation of the calcium release-activated calcium channel: Recent progress from experiments and molecular modeling. Biopolymers 2021; 111:e23392. [PMID: 33460071 DOI: 10.1002/bip.23392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/29/2020] [Accepted: 07/01/2020] [Indexed: 11/08/2022]
Abstract
Calcium release-activated calcium (CRAC) channels are highly calcium ion (Ca2+)-selective channels in the plasma membrane. The transient drop of endoplasmic reticulum Ca2+ level activates its calcium sensor stromal interaction molecule (STIM) and then triggers the gating of the CRAC channel pore unit Orai. This process involves a variety of activities of the immune system. Therefore, understanding how the activation and regulation of the CRAC channel can be accomplished is essential. Here we briefly summarize the recent progress on Orai gating and its regulation by 2-aminoethoxydiphenylborate (2-APB) obtained from structural biology studies, biochemical and electrophysiological measurements, as well as molecular modeling. Indeed, integration between experiments and computations has further deepened our understanding of the channel gating and regulation.
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Affiliation(s)
- Jun Huo
- Kuang Yaming Honors School, Nanjing University, Nanjing, China
| | - Hao Dong
- Kuang Yaming Honors School, Nanjing University, Nanjing, China.,Institute for Brain Sciences, Nanjing University, Nanjing, China
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22
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Das C, Faught E, Vijayan MM. Cortisol rapidly stimulates calcium waves in the developing trunk muscle of zebrafish. Mol Cell Endocrinol 2021; 520:111067. [PMID: 33129866 DOI: 10.1016/j.mce.2020.111067] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 10/09/2020] [Accepted: 10/21/2020] [Indexed: 02/07/2023]
Abstract
Glucocorticoids (GCs) play a role in stress coping by activating the glucocorticoid receptor (GR), a ligand-bound transcription factor. GCs also exert rapid effects that are nongenomic by modulating second messenger signaling, including Ca2+. However, the mechanism of action of GCs in modulating cytoplasmic free calcium level ([Ca2+]i) is unclear. We hypothesized that cortisol increases ([Ca2+]i) in zebrafish (Danio rerio) muscle, and this is independent of GR activation. Indeed, cortisol rapidly stimulated ([Ca2+]i) rise in the developing trunk muscle (DTM), and this response was not abolished in the GR knockout zebrafish. The rapid cortisol-induced ([Ca2+]i) rise was reduced with EGTA, and completely abolished by the pharmacological inhibition of the calcium release-activated calcium channel (CRACC). Also, cortisol stimulation rapidly increased the expression of Orai1, the pore forming protein subunit of CRACC, in the DTM. Altogether, rapid nongenomic action of cortisol on muscle function may involve Ca2+ signaling by CRACC gating in zebrafish.
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Affiliation(s)
- Chinmayee Das
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, T2N1N4, Canada
| | - Erin Faught
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, T2N1N4, Canada
| | - Mathilakath M Vijayan
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, T2N1N4, Canada.
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23
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Kim JH, Park EY, Hwang KH, Park KS, Choi SJ, Cha SK. Soluble αKlotho downregulates Orai1-mediated store-operated Ca 2+ entry via PI3K-dependent signaling. Pflugers Arch 2021; 473:647-658. [PMID: 33386992 PMCID: PMC8049930 DOI: 10.1007/s00424-020-02510-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 12/20/2020] [Accepted: 12/23/2020] [Indexed: 12/17/2022]
Abstract
αKlotho is a type 1 transmembrane anti-aging protein. αKlotho-deficient mice have premature aging phenotypes and an imbalance of ion homeostasis including Ca2+ and phosphate. Soluble αKlotho is known to regulate multiple ion channels and growth factor-mediated phosphoinositide-3-kinase (PI3K) signaling. Store-operated Ca2+ entry (SOCE) mediated by pore-forming subunit Orai1 and ER Ca2+ sensor STIM1 is a ubiquitous Ca2+ influx mechanism and has been implicated in multiple diseases. However, it is currently unknown whether soluble αKlotho regulates Orai1-mediated SOCE via PI3K-dependent signaling. Among the Klotho family, αKlotho downregulates SOCE while βKlotho or γKlotho does not affect SOCE. Soluble αKlotho suppresses serum-stimulated SOCE and Ca2+ release-activated Ca2+ (CRAC) channel currents. Serum increases the cell-surface abundance of Orai1 via stimulating vesicular exocytosis of the channel. The serum-stimulated SOCE and cell-surface abundance of Orai1 are inhibited by the preincubation of αKlotho protein or PI3K inhibitors. Moreover, the inhibition of SOCE and cell-surface abundance of Orai1 by pretreatment of brefeldin A or tetanus toxin or PI3K inhibitors prevents further inhibition by αKlotho. Functionally, we further show that soluble αKlotho ameliorates serum-stimulated SOCE and cell migration in breast and lung cancer cells. These results demonstrate that soluble αKlotho downregulates SOCE by inhibiting PI3K-driven vesicular exocytosis of the Orai1 channel and contributes to the suppression of SOCE-mediated tumor cell migration.
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Affiliation(s)
- Ji-Hee Kim
- Department of Physiology, Yonsei University Wonju College of Medicine, 20 Ilsan-ro, Wonju, Gangwondo, 26426, Republic of Korea
- Department of Global Medical Science, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
- Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
- Institute of Mitochondrial Medicine, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - Eun Young Park
- Department of Global Medical Science, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
- Department of Obstetrics and Gynecology, Yonsei University Wonju College of Medicine, 20 Ilsan-ro, Wonju, Gangwondo, 26426, Republic of Korea
| | - Kyu-Hee Hwang
- Department of Physiology, Yonsei University Wonju College of Medicine, 20 Ilsan-ro, Wonju, Gangwondo, 26426, Republic of Korea
- Department of Global Medical Science, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
- Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
- Institute of Mitochondrial Medicine, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - Kyu-Sang Park
- Department of Physiology, Yonsei University Wonju College of Medicine, 20 Ilsan-ro, Wonju, Gangwondo, 26426, Republic of Korea
- Department of Global Medical Science, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
- Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
- Institute of Mitochondrial Medicine, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - Seong Jin Choi
- Department of Obstetrics and Gynecology, Yonsei University Wonju College of Medicine, 20 Ilsan-ro, Wonju, Gangwondo, 26426, Republic of Korea.
| | - Seung-Kuy Cha
- Department of Physiology, Yonsei University Wonju College of Medicine, 20 Ilsan-ro, Wonju, Gangwondo, 26426, Republic of Korea.
- Department of Global Medical Science, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.
- Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.
- Institute of Mitochondrial Medicine, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.
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Tiffner A, Schober R, Höglinger C, Bonhenry D, Pandey S, Lunz V, Sallinger M, Frischauf I, Fahrner M, Lindinger S, Maltan L, Berlansky S, Stadlbauer M, Schindl R, Ettrich R, Romanin C, Derler I. CRAC channel opening is determined by a series of Orai1 gating checkpoints in the transmembrane and cytosolic regions. J Biol Chem 2021; 296:100224. [PMID: 33361160 PMCID: PMC7948504 DOI: 10.1074/jbc.ra120.015548] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 12/15/2020] [Accepted: 12/22/2020] [Indexed: 12/13/2022] Open
Abstract
The initial activation step in the gating of ubiquitously expressed Orai1 calcium (Ca2+) ion channels represents the activation of the Ca2+-sensor protein STIM1 upon Ca2+ store depletion of the endoplasmic reticulum. Previous studies using constitutively active Orai1 mutants gave rise to, but did not directly test, the hypothesis that STIM1-mediated Orai1 pore opening is accompanied by a global conformational change of all Orai transmembrane domain (TM) helices within the channel complex. We prove that a local conformational change spreads omnidirectionally within the Orai1 complex. Our results demonstrate that these locally induced global, opening-permissive TM motions are indispensable for pore opening and require clearance of a series of Orai1 gating checkpoints. We discovered these gating checkpoints in the middle and cytosolic extended TM domain regions. Our findings are based on a library of double point mutants that contain each one loss-of-function with one gain-of-function point mutation in a series of possible combinations. We demonstrated that an array of loss-of-function mutations are dominant over most gain-of-function mutations within the same as well as of an adjacent Orai subunit. We further identified inter- and intramolecular salt-bridge interactions of Orai subunits as a core element of an opening-permissive Orai channel architecture. Collectively, clearance and synergistic action of all these gating checkpoints are required to allow STIM1 coupling and Orai1 pore opening. Our results unravel novel insights in the preconditions of the unique fingerprint of CRAC channel activation, provide a valuable source for future structural resolutions, and help to understand the molecular basis of disease-causing mutations.
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Affiliation(s)
- Adéla Tiffner
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Linz, Austria
| | - Romana Schober
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Linz, Austria
| | - Carmen Höglinger
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Linz, Austria
| | - Daniel Bonhenry
- Center for Nanobiology and Structural Biology, Institute of Microbiology, Czech Academy of Sciences, Nove Hrady, Czechia
| | - Saurabh Pandey
- Center for Nanobiology and Structural Biology, Institute of Microbiology, Czech Academy of Sciences, Nove Hrady, Czechia
| | - Victoria Lunz
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Linz, Austria
| | - Matthias Sallinger
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Linz, Austria
| | - Irene Frischauf
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Linz, Austria
| | - Marc Fahrner
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Linz, Austria
| | - Sonja Lindinger
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Linz, Austria
| | - Lena Maltan
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Linz, Austria
| | - Sascha Berlansky
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Linz, Austria
| | - Michael Stadlbauer
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Linz, Austria
| | - Rainer Schindl
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Rudiger Ettrich
- College of Biomedical Sciences, Larkin University, Miami, Florida, USA; Faculty of Mathematics and Physics, Charles University, Prague, Czechia; Department of Cellular Biology & Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida, USA
| | - Christoph Romanin
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Linz, Austria
| | - Isabella Derler
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Linz, Austria.
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25
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Barde PJ, Viswanadha S, Veeraraghavan S, Vakkalanka SV, Nair A. A first-in-human study to evaluate the safety, tolerability and pharmacokinetics of RP3128, an oral calcium release-activated calcium (CRAC) channel modulator in healthy volunteers. J Clin Pharm Ther 2020; 46:677-687. [PMID: 33314326 DOI: 10.1111/jcpt.13322] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 11/09/2020] [Accepted: 11/16/2020] [Indexed: 12/21/2022]
Abstract
WHAT IS KNOWN AND OBJECTIVE RP3128, a novel, orally available modulator of calcium released activated calcium (CRAC) channel, is being developed for the potential treatment of autoimmune and inflammatory diseases. RP3128 showed nano-molar potency and activity in a range of in vitro and in vivo models of inflammation. We report a first-in-human study investigating the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of RP3128 in healthy subjects. METHODS A randomized, double-blind, placebo-controlled trial of single (25, 50, 100, 200 and 400 mg) and multiple (7 days: 25, 100 and 400 mg once daily) doses of RP3128 were performed. Thirty-two and 24 subjects were randomized in the single ascending dose (SAD) and multiple ascending dose (MAD) parts, respectively. RESULTS AND DISCUSSION RP3128 was well tolerated, with no dose-limiting toxicity at single and multiple doses. Incidence of treatment emergent adverse events (TEAEs) did not increase with ascending RP3128 doses. No changes were seen in cognitive function and ECG parameters. RP3128 was rapidly absorbed. Elimination was slow with a half-life of more than 80 h. Exposures increased with increasing doses. Accumulation was seen on repeated dosing. PD response, as evidenced by lower plasma levels of tumour necrosis factor-alfa (TNFα) and interleukin-4 (IL-4), was seen when compared to pre-dose values or placebo. WHAT IS NEW AND CONCLUSION The safety, tolerability and PK/PD profile of RP3128 demonstrates its potential to be developed in inflammatory disorders and support further clinical development (ClinicalTrials.gov number: NCT02958982).
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Affiliation(s)
- Prajak J Barde
- Rhizen Pharmaceuticals SA, La Chaux-de-Fonds, Switzerland
| | | | | | | | - Ajit Nair
- Rhizen Pharmaceuticals SA, La Chaux-de-Fonds, Switzerland
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26
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Hori K, Tsujikawa S, Novakovic MM, Yamashita M, Prakriya M. Regulation of chemoconvulsant-induced seizures by store-operated Orai1 channels. J Physiol 2020; 598:5391-5409. [PMID: 32851638 DOI: 10.1113/jp280119] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 08/25/2020] [Indexed: 12/19/2022] Open
Abstract
KEY POINTS Temporal lobe epilepsy is a complex neurological disease caused by imbalance of excitation and inhibition in the brain. Growing literature implicates altered Ca2+ signalling in many aspects of epilepsy but the diversity of Ca2+ channels that regulate this syndrome are not well-understood. Here, we report that mice lacking the store-operated Ca2+ channel, Orai1, in the brain show markedly stronger seizures in response to the chemoconvulsants, kainic acid and pilocarpine. Electrophysiological analysis reveals that selective deletion of Orai1 channels in inhibitory neurons disables chemoconvulsant-induced excitation of GABAergic neurons in the CA1 hippocampus. Likewise, deletion of Orai1 in GABAergic neurons abrogates the chemoconvulsant-induced burst of spontaneous inhibitory postsynaptic currents (sIPSCs) on CA1 pyramidal neurons in the hippocampus. This loss of chemoconvulsant inhibition likely aggravates status epilepticus in Orai1 KO mice. These results identify Orai1 channels as regulators of hippocampal interneuron excitability and seizures. ABSTRACT Store-operated Orai1 channels are a major mechanism for Ca2+ entry in many cells and mediate numerous functions including gene expression, cytokine production and gliotransmitter release. Orai1 is expressed in many regions of the mammalian brain; however, its role in regulating neuronal excitability, synaptic function and brain disorders has only now begun to be investigated. To investigate a potential role of Orai1 channels in status epilepticus induced by chemoconvulsants, we examined acute seizures evoked by intraperitoneal injections of kainic acid (KA) and pilocarpine in mice with a conditional deletion of Orai1 (or its activator STIM1) in the brain. Brain-specific Orai1 and STIM1 knockout (KO) mice exhibited significantly stronger seizures (P = 0.00003 and P < 0.00001), and higher chemoconvulsant-induced mortality (P = 0.02) compared with wildtype (WT) littermates. Electrophysiological recordings in hippocampal brain slices revealed that KA stimulated the activity of inhibitory interneurons in the CA1 hippocampus (P = 0.04) which failed to occur in Orai1 KO mice. Further, KA and pilocarpine increased the frequency of spontaneous IPSCs in CA1 pyramidal neurons >twofold (KA: P = 0.04; pilocarpine: P = 0.0002) which was abolished in Orai1 KO mice. Mice with selective deletion of Orai1 in GABAergic neurons alone also showed stronger seizures to KA (P = 0.001) and pilocarpine (P < 0.00001) and loss of chemoconvulsant-induced increases in sIPSC responses compared with WT controls. We conclude that Orai1 channels regulate chemoconvulsant-induced excitation in GABAergic neurons and that destabilization of the excitatory/inhibitory balance in Orai1 KO mice aggravates chemoconvulsant-mediated seizures. These results identify Orai1 channels as novel molecular regulators of hippocampal neuronal excitability and seizures.
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Affiliation(s)
- Kotaro Hori
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Shogo Tsujikawa
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Michaela M Novakovic
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Megumi Yamashita
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Murali Prakriya
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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Vaeth M, Kahlfuss S, Feske S. CRAC Channels and Calcium Signaling in T Cell-Mediated Immunity. Trends Immunol 2020; 41:878-901. [PMID: 32711944 DOI: 10.1016/j.it.2020.06.012] [Citation(s) in RCA: 105] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 06/19/2020] [Accepted: 06/24/2020] [Indexed: 12/22/2022]
Abstract
Calcium (Ca2+) signals play fundamental roles in immune cell function. The main sources of Ca2+ influx in mammalian lymphocytes following antigen receptor stimulation are Ca2+ release-activated Ca2+ (CRAC) channels. These are formed by ORAI proteins in the plasma membrane and are activated by stromal interaction molecules (STIM) located in the endoplasmic reticulum (ER). Human loss-of-function (LOF) mutations in ORAI1 and STIM1 that abolish Ca2+ influx cause a unique disease syndrome called CRAC channelopathy that is characterized by immunodeficiency autoimmunity and non-immunological symptoms. Studies in mice lacking Stim and Orai genes have illuminated many cellular and molecular mechanisms by which these molecules control lymphocyte function. CRAC channels are required for the differentiation and function of several T lymphocyte subsets that provide immunity to infection, mediate inflammation and prevent autoimmunity. This review examines new insights into how CRAC channels control T cell-mediated immunity.
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Affiliation(s)
- Martin Vaeth
- Institute of Systems Immunology, Julius-Maximilians University of Würzburg, Würzburg, Germany; Department of Pathology, New York University School of Medicine, New York, NY, USA
| | - Sascha Kahlfuss
- Institute of Molecular and Clinical Immunology, Health Campus Immunology, Infectiology, and Inflammation, Otto-von-Guericke University Magdeburg, Magdeburg, Germany; Department of Pathology, New York University School of Medicine, New York, NY, USA
| | - Stefan Feske
- Department of Pathology, New York University School of Medicine, New York, NY, USA.
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Derler I, Romanin C. Natural photoswitches expose STIM1 activation steps. Cell Calcium 2020; 90:102240. [PMID: 32574907 DOI: 10.1016/j.ceca.2020.102240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 06/05/2020] [Accepted: 06/05/2020] [Indexed: 10/24/2022]
Abstract
STIM1, an ER-located Ca2+ sensor, activates Orai1 channels upon Ca2+-storedepletion. Prior to this, STIM1 undergoes a sequence of conformational changes, which cannot be controlled individually with high spatiotemporal resolution. Ma et al. [1] used the power of optogenetic engineering to transfer light-sensitivity to STIM1 and precisely characterize individual STIM1 activation steps.
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Affiliation(s)
- Isabella Derler
- Institute of Biophysics, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria.
| | - Christoph Romanin
- Institute of Biophysics, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria.
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Abstract
Genetically-encoded calcium actuators (GECAs) stemmed from STIM1 have enabled optical activation of endogenous ORAI1 channels in both excitable and non-excitable tissues. These GECAs offer new non-invasive means to probe the structure-function relations of calcium channels and wirelessly control the behavior of awake mice.
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Affiliation(s)
- Guolin Ma
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M University, Houston, TX 77030, USA.
| | - Yubin Zhou
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M University, Houston, TX 77030, USA.
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30
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Khan HY, Mpilla GB, Sexton R, Viswanadha S, Penmetsa KV, Aboukameel A, Diab M, Kamgar M, Al-Hallak MN, Szlaczky M, Tesfaye A, Kim S, Philip PA, Mohammad RM, Azmi AS. Calcium Release-Activated Calcium (CRAC) Channel Inhibition Suppresses Pancreatic Ductal Adenocarcinoma Cell Proliferation and Patient-Derived Tumor Growth. Cancers (Basel) 2020; 12:E750. [PMID: 32235707 DOI: 10.3390/cancers12030750] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 03/17/2020] [Accepted: 03/17/2020] [Indexed: 01/12/2023] Open
Abstract
Pancreatic ductal adenocarcinoma (PDAC) remains an unmet clinical problem in urgent need of newer molecularly driven treatment modalities. Calcium signals, particularly those associated with calcium release-activated calcium (CRAC) channels, are known to influence the development, growth, and metastasis of many cancers. This is the first study investigating the impact of CRAC channel inhibition on PDAC cell lines and patient-derived tumor models. PDAC cell lines were exposed to a novel CRAC channel inhibitor, RP4010, in the presence or absence of standard of care drugs such as gemcitabine and nab-paclitaxel. The in vivo efficacy of RP4010 was evaluated in a hyaluronan-positive PDAC patient-derived xenograft (PDx) in the presence or absence of chemotherapeutic agents. Treatment of PDAC cell lines with single-agent RP4010 decreased cell growth, while the combination with gemcitabine/nab-paclitaxel exhibited synergy at certain dose combinations. Molecular analysis showed that RP4010 modulated the levels of markers associated with CRAC channel signaling pathways. Further, the combination treatment was observed to accentuate the effect of RP4010 on molecular markers of CRAC signaling. Anti-tumor activity of RP4010 was enhanced in the presence of gemcitabine/nab-paclitaxel in a PDAC PDx model. Our study indicates that targeting CRAC channel could be a viable therapeutic option in PDAC that warrants further clinical evaluation.
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31
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Ramakrishnan AM, Kumar P, Chatterjee S, Sankaranarayanan K. Differential expression of CRAC channel in alloxan induced Diabetic BALB/c mice. Immunopharmacol Immunotoxicol 2020; 42:48-55. [PMID: 31983259 DOI: 10.1080/08923973.2020.1716788] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Objectives: CRAC (Calcium Release Activated Calcium) channel is one of the most important channels regulating calcium influx and has been involved in many autoimmune diseases. The contribution of CRAC channel in the pathogenesis of Type 1 Diabetes (T1D) has not been described much. Thus, we aimed to study the expression of CRAC channel and inflammatory cytokines like IL-1β (Interleukin -1β) and TNF-α (Tumor Necrosis Factor-α) in the spleen-derived cytotoxic T cells, Bone marrow monocytes (BMM) and macrophages differentiated from BMM in the alloxan induced T1D mice.Materials and methods: BALB/c mice treated with alloxan and vehicle control for 12 and 24 h. Spleen derived T cells; Bone marrow derived monocytes were isolated from the control and diabetic BALB/c mice as well as macrophages differentiated from the control and diabetic BMM.Results: We observed increased expression of CRAC channel components like STIM1 (Stromal Interaction Molecule), ORAI1 and ORAI2 and inflammatory cytokines like IL-1β and TNF-α in the spleen derived cytotoxic T cells and Macrophages differentiated from BMM as well as the downregulated expression of the same and CRAC channel in BMM of 12 and 24 h alloxan induced BALB/c mice.Conclusions: This study suggests that differential expression of CRAC channel correlated with the expression of inflammatory cytokines, thus CRAC channel might be responsible for the increased production of inflammatory cytokines in the alloxan induced T1D mice.
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Affiliation(s)
| | - Pavitra Kumar
- Vascular Biology laboratory, AU-KBC Research Centre, MIT Campus of Anna University, Chennai, India
| | - Suvro Chatterjee
- Vascular Biology laboratory, AU-KBC Research Centre, MIT Campus of Anna University, Chennai, India
| | - Kavitha Sankaranarayanan
- Ion Channel Biology Laboratory, AU-KBC Research Centre, MIT Campus of Anna University, Chennai, India
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Abstract
Introduction The Ca2+release-activated Ca2+ (CRAC) channel, composed of Orai and STIM proteins, represents one of the main routes of Ca2+ entry in most non-excitable cells. There is accumulating evidence to suggest that CRAC channel can influence various processes associated with tumorigenesis. Overexpression of CRAC channel proteins has been observed in several types of cancer tissues and cells, indicating that blocking CRAC channel activated Ca2+ influx can have therapeutic benefits for cancer patients. Areas covered In this review, we have primarily focused on the molecular composition and activation mechanism of CRAC channel as well as the myriad roles this Ca2+ channel play in various cancers. We further describe relevant information about several efforts aimed at developing CRAC channel blockers and their likely implications for cancer therapy. We have extensively utilized the available literature on PubMed to this end. Expert opinion The possibility of targeting CRAC channel mediated Ca2+ entry in cancer cells has generated considerable interest in recent years. Use of CRAC channel blockers in cancer preclinical studies and clinical trials has been relatively limited as compared to other diseases. The future lies in developing and testing more potent and selective drugs that target cancer cell specific CRAC channel proteins, hence opening better avenues for cancer therapeutic development.
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Affiliation(s)
- Husain Yar Khan
- Department of Oncology, Wayne State University School of Medicine, Detroit MI 48201 USA
| | - Iqra Mazahir
- Department of Medical Elementology and Toxicology, Jamia Hamdard, Block D, Hamdard Nagar, New Delhi, Delhi 110062, India
| | - Shriya Reddy
- Department of Oncology, Wayne State University School of Medicine, Detroit MI 48201 USA
| | - Farzeen Fazili
- Department of Oncology, Wayne State University School of Medicine, Detroit MI 48201 USA
| | - AsfarSohail Azmi
- Department of Oncology, Wayne State University School of Medicine, Detroit MI 48201 USA
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Abstract
Ca2+ release activated Ca2+ (CRAC) channels represent a primary pathway for Ca2+ to enter non-excitable cells. The two key players in this process are the stromal interaction molecule (STIM), a Ca2+ sensor embedded in the membrane of the endoplasmic reticulum, and Orai, a highly Ca2+ selective ion channel located in the plasma membrane. Upon depletion of the internal Ca2+ stores, STIM is activated, oligomerizes, couples to and activates Orai. This review provides an overview of novel findings about the CRAC channel activation mechanisms, structure and gating. In addition, it highlights, among diverse STIM and Orai mutants, also the disease-related mutants and their implications.
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Affiliation(s)
- Carmen Butorac
- Institute of Biophysics, Johannes Kepler University of Linz, Linz, Austria
| | - Adéla Krizova
- Institute of Biophysics, Johannes Kepler University of Linz, Linz, Austria
| | - Isabella Derler
- Institute of Biophysics, Johannes Kepler University of Linz, Linz, Austria.
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Saint Fleur-Lominy S, Maus M, Vaeth M, Lange I, Zee I, Suh D, Liu C, Wu X, Tikhonova A, Aifantis I, Feske S. STIM1 and STIM2 Mediate Cancer-Induced Inflammation in T Cell Acute Lymphoblastic Leukemia. Cell Rep 2019; 24:3045-3060.e5. [PMID: 30208327 PMCID: PMC6170166 DOI: 10.1016/j.celrep.2018.08.030] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 06/04/2018] [Accepted: 08/10/2018] [Indexed: 12/12/2022] Open
Abstract
T cell acute lymphoblastic leukemia (T-ALL) is commonly associated with activating mutations in the NOTCH1 pathway. Recent reports have shown a link between NOTCH1 signaling and intracellular Ca2+ homeostasis in T-ALL. Here, we investigate the role of store-operated Ca2+ entry (SOCE) mediated by the Ca2+ channel ORAI1 and its activators STIM1 and STIM2 in T-ALL. Deletion of STIM1 and STIM2 in leukemic cells abolishes SOCE and significantly prolongs the survival of mice in a NOTCH1-dependent model of T-ALL. The survival advantage is unrelated to the leukemic cell burden but is associated with the SOCE-dependent ability of malignant T lymphoblasts to cause inflammation in leukemia-infiltrated organs. Mice with STIM1/STIM2-deficient T-ALL show a markedly reduced necroinflammatory response in leukemia-infiltrated organs and downregulation of signaling pathways previously linked to cancer-induced inflammation. Our study shows that leukemic T lymphoblasts cause inflammation of leukemia-infiltrated organs that is dependent on SOCE. T cell acute lymphoblastic leukemia (T-ALL) is an aggressive cancer of T cell progenitors affecting children and adults. Saint Fleur-Lominy et al. show that calcium influx mediated by STIM1 and STIM2 promotes the proinflammatory function of leukemic cells and premature death from leukemia.
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Affiliation(s)
- Shella Saint Fleur-Lominy
- Department of Medicine, New York University School of Medicine, New York, NY 10016, USA; Laura and Isaac Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016, USA
| | - Mate Maus
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Martin Vaeth
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Ingo Lange
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Isabelle Zee
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - David Suh
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Cynthia Liu
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Xiaojun Wu
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Anastasia Tikhonova
- Laura and Isaac Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016, USA; Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Iannis Aifantis
- Laura and Isaac Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016, USA; Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Stefan Feske
- Laura and Isaac Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016, USA; Department of Pathology, New York University School of Medicine, New York, NY 10016, USA.
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Bhuvaneshwari S, Sankaranarayanan K. Structural and Mechanistic Insights of CRAC Channel as a Drug Target in Autoimmune Disorder. Curr Drug Targets 2019; 21:55-75. [PMID: 31556856 DOI: 10.2174/1389450120666190926150258] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 08/20/2019] [Accepted: 08/20/2019] [Indexed: 01/17/2023]
Abstract
BACKGROUND Calcium (Ca2+) ion is a major intracellular signaling messenger, controlling a diverse array of cellular functions like gene expression, secretion, cell growth, proliferation, and apoptosis. The major mechanism controlling this Ca2+ homeostasis is store-operated Ca2+ release-activated Ca2+ (CRAC) channels. CRAC channels are integral membrane protein majorly constituted via two proteins, the stromal interaction molecule (STIM) and ORAI. Following Ca2+ depletion in the Endoplasmic reticulum (ER) store, STIM1 interacts with ORAI1 and leads to the opening of the CRAC channel gate and consequently allows the influx of Ca2+ ions. A plethora of studies report that aberrant CRAC channel activity due to Loss- or gain-of-function mutations in ORAI1 and STIM1 disturbs this Ca2+ homeostasis and causes several autoimmune disorders. Hence, it clearly indicates that the therapeutic target of CRAC channels provides the space for a new approach to treat autoimmune disorders. OBJECTIVE This review aims to provide the key structural and mechanical insights of STIM1, ORAI1 and other molecular modulators involved in CRAC channel regulation. RESULTS AND CONCLUSION Understanding the structure and function of the protein is the foremost step towards improving the effective target specificity by limiting their potential side effects. Herein, the review mainly focusses on the structural underpinnings of the CRAC channel gating mechanism along with its biophysical properties that would provide the solid foundation to aid the development of novel targeted drugs for an autoimmune disorder. Finally, the immune deficiencies caused due to mutations in CRAC channel and currently used pharmacological blockers with their limitation are briefly summarized.
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Affiliation(s)
- Sampath Bhuvaneshwari
- Ion Channel Biology Laboratory, AU-KBC Research Centre, Madras Institute of Technology, Anna University, Chrompet, Chennai -600 044, India
| | - Kavitha Sankaranarayanan
- Ion Channel Biology Laboratory, AU-KBC Research Centre, Madras Institute of Technology, Anna University, Chrompet, Chennai -600 044, India
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36
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Krizova A, Maltan L, Derler I. Critical parameters maintaining authentic CRAC channel hallmarks. Eur Biophys J 2019; 48:425-445. [PMID: 30903264 PMCID: PMC6647248 DOI: 10.1007/s00249-019-01355-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 12/20/2018] [Accepted: 03/06/2019] [Indexed: 12/20/2022]
Abstract
Ca2+ ions represent versatile second messengers that regulate a huge diversity of processes throughout the cell's life. One prominent Ca2+ entry pathway into the cell is the Ca2+ release-activated Ca2+ (CRAC) ion channel. It is fully reconstituted by the two molecular key players: the stromal interaction molecule (STIM1) and Orai. STIM1 is a Ca2+ sensor located in the membrane of the endoplasmic reticulum, and Orai, a highly Ca2+ selective ion channel embedded in the plasma membrane. Ca2+ store-depletion leads initially to the activation of STIM1 which subsequently activates Orai channels via direct binding. Authentic CRAC channel hallmarks and biophysical characteristics include high Ca2+ selectivity with a reversal potential in the range of + 50 mV, small unitary conductance, fast Ca2+-dependent inactivation and enhancements in currents upon the switch from a Na+-containing divalent-free to a Ca2+-containing solution. This review provides an overview on the critical determinants and structures within the STIM1 and Orai proteins that establish these prominent CRAC channel characteristics.
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Affiliation(s)
- Adéla Krizova
- Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020, Linz, Austria
| | - Lena Maltan
- Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020, Linz, Austria
| | - Isabella Derler
- Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020, Linz, Austria.
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Carretta MD, Hidalgo MA, Burgos RA. Indirect Measurement of CRAC Channel Activity Using NFAT Nuclear Translocation by Flow Cytometry in Jurkat Cells. Methods Mol Biol 2018; 1843:83-94. [PMID: 30203279 DOI: 10.1007/978-1-4939-8704-7_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Flow cytometry is a powerful technology to assess the presence of NFAT in the nuclei after CRAC channel activation. Here we described a simplified procedure for the analysis of CRAC channel activity using NFAT nuclear translocation by flow cytometry, based on the isolation of Jurkat E6-1 cell nuclei.
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Yeung PSW, Yamashita M, Prakriya M. Molecular basis of allosteric Orai1 channel activation by STIM1. J Physiol 2019; 598:1707-1723. [PMID: 30950063 DOI: 10.1113/jp276550] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 03/19/2019] [Indexed: 12/13/2022] Open
Abstract
Store-operated Ca2+ entry through Orai1 channels is a primary mechanism for Ca2+ entry in many cells and mediates numerous cellular effector functions ranging from gene transcription to exocytosis. Orai1 channels are amongst the most Ca2+ -selective channels known and are activated by direct physical interactions with the endoplasmic reticulum Ca2+ sensor stromal interaction molecule 1 (STIM1) in response to store depletion triggered by stimulation of a variety of cell surface G-protein coupled and tyrosine kinase receptors. Work in the last decade has revealed that the Orai1 gating process is highly cooperative and strongly allosteric, likely driven by a wave of interdependent conformational changes throughout the protein originating in the peripheral C-terminal ligand binding site and culminating in pore opening. In this review, we survey the structural and molecular features in Orai1 that contribute to channel gating and consider how they give rise to the unique biophysical fingerprint of Orai1 currents.
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Affiliation(s)
- Priscilla See-Wai Yeung
- Department of Pharmacology, Northwestern University, Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Megumi Yamashita
- Department of Pharmacology, Northwestern University, Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Murali Prakriya
- Department of Pharmacology, Northwestern University, Feinberg School of Medicine, Chicago, IL, 60611, USA
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Abstract
Ca2+ release-activated Ca2+ (CRAC) channels are intimately linked with health and disease. The gene encoding the CRAC channel, ORAI1, was discovered in part by genetic analysis of patients with abolished CRAC channel function. And patients with autosomal recessive loss-of-function (LOF) mutations in ORAI1 and its activator stromal interaction molecule 1 (STIM1) that abolish CRAC channel function and store-operated Ca2+ entry (SOCE) define essential functions of CRAC channels in health and disease. Conversely, gain-of-function (GOF) mutations in ORAI1 and STIM1 are associated with tubular aggregate myopathy (TAM) and Stormorken syndrome due to constitutive CRAC channel activation. In addition, genetically engineered animal models of ORAI and STIM function have provided important insights into the physiological and pathophysiological roles of CRAC channels in cell types and organs beyond those affected in human patients. The picture emerging from this body of work shows CRAC channels as important regulators of cell function in many tissues, and as potential drug targets for the treatment of autoimmune and inflammatory disorders.
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Affiliation(s)
- Stefan Feske
- Department of Pathology, New York University School of Medicine, New York, NY, 10016, USA.
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Schmidt B, Alansary D, Bogeski I, Niemeyer BA, Rieger H. Reaction-diffusion model for STIM-ORAI interaction: The role of ROS and mutations. J Theor Biol 2019; 470:64-75. [PMID: 30853394 DOI: 10.1016/j.jtbi.2019.02.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 02/13/2019] [Accepted: 02/18/2019] [Indexed: 11/30/2022]
Abstract
Release of Ca2+ from endoplasmatic retriculum (ER) Ca2+ stores causes stromal interaction molecules (STIM) in the ER membrane and ORAI proteins in the plasma membrane (PM) to interact and form the Ca2+ release activated Ca2+ (CRAC) channels, which represent a major Ca2+ entry route in non-excitable cells and thus control various cell functions. It is experimentally possible to mutate ORAI1 proteins and therefore modify, especially block, the Ca2+ influx into the cell. On the basis of the model of Hoover and Lewis (2011), we formulate a reaction-diffusion model to quantify the STIM1-ORAI1 interaction during CRAC channel formation and analyze different ORAI1 channel stoichiometries and different ratios of STIM1 and ORAI1 in comparison with experimental data. We incorporate the inhibition of ORAI1 channels by ROS into our model and calculate its contribution to the CRAC channel amplitude. We observe a large decrease of the CRAC channel amplitude evoked by mutations of ORAI1 proteins.
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Affiliation(s)
- Barbara Schmidt
- Center for Biophysics & Department of Theoretical Physics, Saarland University, Saarbrücken 66041, Germany; Department of Molecular Biophysics, Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg 66421, Germany; Department of Biophysics, Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg 66421, Germany.
| | - Dalia Alansary
- Department of Molecular Biophysics, Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg 66421, Germany.
| | - Ivan Bogeski
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg 66421, Germany; Molecular Physiology, Institute of Cardiovascular Physiology, University Medical Center Georg-August-University, Göttingen 37073, Germany.
| | - Barbara A Niemeyer
- Department of Molecular Biophysics, Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg 66421, Germany.
| | - Heiko Rieger
- Center for Biophysics & Department of Theoretical Physics, Saarland University, Saarbrücken 66041, Germany.
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Yen M, Lewis RS. Numbers count: How STIM and Orai stoichiometry affect store-operated calcium entry. Cell Calcium 2019; 79:35-43. [PMID: 30807904 DOI: 10.1016/j.ceca.2019.02.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 02/06/2019] [Accepted: 02/06/2019] [Indexed: 02/06/2023]
Abstract
Substantial progress has been made in the past several years in establishing the stoichiometries of STIM and Orai proteins and understanding their influence on store-operated calcium entry. Depletion of ER Ca2+ triggers STIM1 to accumulate at ER-plasma membrane junctions where it binds and opens Ca2+ release-activated Ca2+ (CRAC) channels. STIM1 is a dimer, and release of Ca2+ from its two luminal domains is reported to promote their association as well as drive formation of higher-order STIM1 oligomers. The CRAC channel, originally thought to be tetrameric, is now considered to be a hexamer of Orai1 subunits based on crystallographic and electrophysiological studies. STIM1 binding activates CRAC channels in a highly nonlinear way, such that all six Orai1 binding sites must be occupied to account for the activation and signature properties of native channels. The structural basis of STIM1 engagement with the channel is currently unclear, with evidence suggesting that STIM1 dimers bind to individual or pairs of Orai1 subunits. This review examines evidence that has led to points of consensus and debate about STIM1 and Orai1 stoichiometries, and explains the importance of STIM-Orai complex stoichiometry for the regulation of store-operated calcium entry.
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Affiliation(s)
- Michelle Yen
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, 94305, United States
| | - Richard S Lewis
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, 94305, United States.
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42
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Clemens RA, Lowell CA. CRAC channel regulation of innate immune cells in health and disease. Cell Calcium 2019; 78:56-65. [PMID: 30641250 DOI: 10.1016/j.ceca.2019.01.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 12/26/2018] [Accepted: 01/08/2019] [Indexed: 01/17/2023]
Abstract
Calcium is a major intracellular signaling messenger in innate immune cells. Similar to other immune cell subsets, the majority of calcium entry into innate immune cells is induced by cell surface receptors that stimulate store-operated calcium entry through calcium-release activated calcium (CRAC) channels. Since the molecular description of the STIM family of calcium sensors and the ORAI family of CRAC channel proteins, the majority of studies support a dominant role for these proteins in calcium signaling in innate cells. In reviewing the literature on CRAC channel function in innate cells, several general themes emerge. All innate cells express multiple members of the STIM and ORAI family members, however the ratio and relative contribution of individual isoforms changes depending on the cell type and activation state of the cell. It is evident that study of functional roles for STIM molecules is clearly ahead of studies of specific ORAI family members in all innate cell types, and that studies of CRAC channels in innate cells are not nearly as advanced as studies in lymphocytes. However, taken together, evidence from both STIM calcium sensors and ORAI channels in innate cells indicates that deficiency of STIM and ORAI proteins tends not to affect the development of any innate cell lineage, but certainly affects their function, in particular activation of the neutrophil oxidase and mast cell activation via IgE receptors. Furthermore, there are clearly hints that therapeutic targeting of CRAC channels in innate cells offers a new approach to various inflammatory and allergic diseases.
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Affiliation(s)
- Regina A Clemens
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, United States.
| | - Clifford A Lowell
- Department of Laboratory Medicine, University of California, San Francisco, CA, United States
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Li ZX, Wang HX, Yang Y, Qi RQ, Li YL, Yu AJ, Gao XH. Susceptibility of epithelial tumour cell lines to hyperthermia. Eur J Dermatol 2018; 28:606-12. [PMID: 30530432 DOI: 10.1684/ejd.2018.3417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Human skin or mucosa exposes cells to both an internal and exogeneous thermal environment and the cells survive within a certain range of temperature. Exogeneous hyperthermia has been applied for the treatment of various types of cancers, fungal disease, and warts. OBJECTIVES To determine whether different cellular components in the skin adapt to hyperthermic conditions differentially and further elucidate the mechanisms involved. MATERIALS & METHODS Cell lines derived from normal and tumour epithelial cells were treated with hyperthermic conditions and tested for viability (using an MTS assay), apoptosis (using a FITC-conjugated annexin V apoptosis detection kit), and changes in intracellular calcium (using a calcium-sensitive fluorescent single-wavelength dye, Fluo-4 AM). RESULTS Thermo-resistance of different cell types was different when cells were subjected to heat at 45̊C for 30 minutes. Stronger effects of hyperthermia were noted on cell viability and apoptosis in epidermal cells relative to their malignant counterparts, except for cell lines harbouring human papillomavirus (HPV). Hyperthermia had a much greater effect on cell viability and apoptosis in a HPV-negative cell line compared to HPV-positive cell lines. We further found that hyperthermia treatment resulted in a strong calcium influx which led to apoptotic cells. However, no obvious increase in apoptosis was observed in cells treated with the CRAC channel selective inhibitor, BTP2, before application of hyperthermia in all cell types, except three cervical cell lines harbouring HPV. CONCLUSION We propose that hyperthermia results in a CRAC-related strong calcium influx which induces apoptosis, with the exception of HPV-positive cells.
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Stauderman KA. CRAC channels as targets for drug discovery and development. Cell Calcium 2018; 74:147-59. [PMID: 30075400 DOI: 10.1016/j.ceca.2018.07.005] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 07/16/2018] [Accepted: 07/16/2018] [Indexed: 12/13/2022]
Abstract
Calcium release-activated calcium (CRAC) channels have been the target of drug discovery for many years. The identification of STIM and Orai proteins as key components of CRAC channels greatly facilitated this process because their co-expression in cell lines produced electrophysiological currents (ICRAC) much larger than those in native cells, making it easier to confirm and characterize the effects of modulatory compounds. A driving force in the quest for CRAC channel drugs has been the immunocompromised phenotype displayed by humans and mice with null or loss-of-function mutations in STIM1 or Orai1, suggesting that CRAC channel inhibitors could be useful therapeutics for autoimmune or inflammatory conditions. Emerging data also suggests that other therapeutic conditions may benefit from CRAC channel inhibition. However, only recently have CRAC channel inhibitors reached clinical trials. This review discusses the challenges associated with drug discovery and development on CRAC channels and the approaches employed to date, as well as the results, starting from initial high-throughput screens for CRAC channel modulators and progressing through target selection and justification, descriptions of pharmacological, safety and toxicological profiles of compounds, and finally the entry of CRAC channel inhibitors into clinical trials.
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45
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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.
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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.
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Abstract
Enamel is the most calcified tissue in vertebrates. It differs from bone in a number of characteristics including its origin from ectodermal epithelium, lack of remodeling capacity by the enamel forming cells, and absence of collagen. The enamel-forming cells known as ameloblasts, choreograph first the synthesis of a unique protein-rich matrix, followed by the mineralization of this matrix into a tissue that is ∼95% mineral. To do this, ameloblasts arrange the coordinated movement of ions across a cell barrier while removing matrix proteins and monitoring extracellular pH using a variety of buffering systems to enable the growth of carbonated apatite crystals. Although our knowledge of these processes and the molecular identity of the proteins involved in transepithelial ion transport has increased in the last decade, it remains limited compared to other cells. Here we present an overview of the evolution and development of enamel, its differences with bone, and describe the ion transport systems associated with ameloblasts.
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Affiliation(s)
- Rodrigo S Lacruz
- Dept. Basic Science and Craniofacial Biology, New York University College of Dentistry, 345 East 24th Street, New York, NY 10010, United States.
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47
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Maus M, Cuk M, Patel B, Lian J, Ouimet M, Kaufmann U, Yang J, Horvath R, Hornig-Do HT, Chrzanowska-Lightowlers ZM, Moore KJ, Cuervo AM, Feske S. Store-Operated Ca 2+ Entry Controls Induction of Lipolysis and the Transcriptional Reprogramming to Lipid Metabolism. Cell Metab 2017; 25:698-712. [PMID: 28132808 PMCID: PMC5342942 DOI: 10.1016/j.cmet.2016.12.021] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 09/01/2016] [Accepted: 12/28/2016] [Indexed: 12/26/2022]
Abstract
Ca2+ signals were reported to control lipid homeostasis, but the Ca2+ channels and pathways involved are largely unknown. Store-operated Ca2+ entry (SOCE) is a ubiquitous Ca2+ influx pathway regulated by stromal interaction molecule 1 (STIM1), STIM2, and the Ca2+ channel ORAI1. We show that SOCE-deficient mice accumulate pathological amounts of lipid droplets in the liver, heart, and skeletal muscle. Cells from patients with loss-of-function mutations in STIM1 or ORAI1 show a similar phenotype, suggesting a cell-intrinsic role for SOCE in the regulation of lipid metabolism. SOCE is crucial to induce mobilization of fatty acids from lipid droplets, lipolysis, and mitochondrial fatty acid oxidation. SOCE regulates cyclic AMP production and the expression of neutral lipases as well as the transcriptional regulators of lipid metabolism, peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α), and peroxisome proliferator-activated receptor α (PPARα). SOCE-deficient cells upregulate lipophagy, which protects them from lipotoxicity. Our data provide evidence for an important role of SOCE in lipid metabolism.
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Affiliation(s)
- Mate Maus
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Mario Cuk
- Department of Pediatrics, Zagreb University Hospital Centre and School of Medicine, 10 000 Zagreb, Croatia
| | - Bindi Patel
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Jayson Lian
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Mireille Ouimet
- Department of Medicine, New York University School of Medicine, New York, NY 10016, USA
| | - Ulrike Kaufmann
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Jun Yang
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Rita Horvath
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, UK
| | - Hue-Tran Hornig-Do
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Zofia M Chrzanowska-Lightowlers
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Kathryn J Moore
- Department of Medicine, New York University School of Medicine, New York, NY 10016, USA
| | - Ana Maria Cuervo
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Stefan Feske
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA.
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Ben-Kasus Nissim T, Zhang X, Elazar A, Roy S, Stolwijk JA, Zhou Y, Motiani RK, Gueguinou M, Hempel N, Hershfinkel M, Gill DL, Trebak M, Sekler I. Mitochondria control store-operated Ca 2+ entry through Na + and redox signals. EMBO J 2017; 36:797-815. [PMID: 28219928 DOI: 10.15252/embj.201592481] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 12/25/2016] [Accepted: 01/05/2017] [Indexed: 02/05/2023] Open
Abstract
Mitochondria exert important control over plasma membrane (PM) Orai1 channels mediating store-operated Ca2+ entry (SOCE). Although the sensing of endoplasmic reticulum (ER) Ca2+ stores by STIM proteins and coupling to Orai1 channels is well understood, how mitochondria communicate with Orai1 channels to regulate SOCE activation remains elusive. Here, we reveal that SOCE is accompanied by a rise in cytosolic Na+ that is critical in activating the mitochondrial Na+/Ca2+ exchanger (NCLX) causing enhanced mitochondrial Na+ uptake and Ca2+ efflux. Omission of extracellular Na+ prevents the cytosolic Na+ rise, inhibits NCLX activity, and impairs SOCE and Orai1 channel current. We show further that SOCE activates a mitochondrial redox transient which is dependent on NCLX and is required for preventing Orai1 inactivation through oxidation of a critical cysteine (Cys195) in the third transmembrane helix of Orai1. We show that mitochondrial targeting of catalase is sufficient to rescue redox transients, SOCE, and Orai1 currents in NCLX-deficient cells. Our findings identify a hitherto unknown NCLX-mediated pathway that coordinates Na+ and Ca2+ signals to effect mitochondrial redox control over SOCE.
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Affiliation(s)
- Tsipi Ben-Kasus Nissim
- The Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Xuexin Zhang
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Assaf Elazar
- The Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Soumitra Roy
- The Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Judith A Stolwijk
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Yandong Zhou
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Rajender K Motiani
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Maxime Gueguinou
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Nadine Hempel
- Department of Pharmacology, The Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Michal Hershfinkel
- The Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Donald L Gill
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Mohamed Trebak
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Israel Sekler
- The Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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Abstract
This chapter focuses on the Orai proteins, Orai1-Orai3, with special emphasis on Orai1, in humans and other mammals, and on the definitive evidence that Orai is the pore subunit of the CRAC channel. It begins by reviewing briefly the defining characteristics of the CRAC channel, then discusses the studies that implicated Orai as part of the store-operated Ca2+ entry pathway and as the CRAC channel pore subunit, and finally examines ongoing work that is providing insights into CRAC channel structure and gating.
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Affiliation(s)
- Aparna Gudlur
- Division of Signalling and Gene Expression, La Jolla Institute for Allergy and Immunology, 9420 Athena Circle, La Jolla, CA, USA.
| | - Patrick G Hogan
- Division of Signalling and Gene Expression, La Jolla Institute for Allergy and Immunology, 9420 Athena Circle, La Jolla, CA, USA.
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50
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Yeung PS, Yamashita M, Prakriya M. Pore opening mechanism of CRAC channels. Cell Calcium 2017; 63:14-9. [PMID: 28108030 DOI: 10.1016/j.ceca.2016.12.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [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.
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