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Abstract
Store-operated Ca(2+) (SOC) entry is one of the major mechanisms to raise intracellular Ca(2+) concentration in non-excitable cells. Ca(2+)-release-activated Ca(2+) (CRAC) channels are a subtype of SOC channels that are extensively characterized in immune cells. Identification of STIM1 as an endoplasmic reticulum Ca(2+) sensor and Orai1 as the pore subunit has dramatically advanced the molecular understanding of CRAC channels. Recent efforts have focused on understanding the physiological aspects of CRAC channels at an organism level using transgenic animal models and at a molecular level using electrophysiological and biochemical tools. In this review, we summarize our current understanding of the interacting partners of Orai and STIM proteins in the regulation of CRAC channel activity and other non-CRAC channel-related functions.
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Affiliation(s)
- Sonal Srikanth
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.
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202
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McNally BA, Prakriya M. Permeation, selectivity and gating in store-operated CRAC channels. J Physiol 2012; 590:4179-91. [PMID: 22586221 DOI: 10.1113/jphysiol.2012.233098] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Store-operated Ca(2+) release-activated Ca(2+) (CRAC) channels are a widespread mechanism for generating cellular Ca(2+) signals and regulate many Ca(2+)-dependent functions, including transcription, motility and proliferation. The opening of CRAC channels in response to depletion of intracellular Ca(2+) stores involves a cascade of cellular events that culminate in direct interactions between STIM1, the endoplasmic reticulum Ca(2+) sensor, and the channels composed of Orai proteins. Evidence gathered over the last two decades indicates that CRAC channels display a unique functional pore fingerprint characterized by exquisite Ca(2+) selectivity, low unitary conductance, and low permeability to large cations. Here, we review the key pore properties of CRAC channels and discuss recent progress in addressing the molecular foundations of these properties. Structure-function and cysteine-scanning studies have revealed the identity and organization of pore-lining residues, including those that form the selectivity filter, providing a structural framework for understanding CRAC channel pore properties. Recent studies in pore mutants that produce STIM1-independent constitutive channel activation indicate that exquisite Ca(2+) selectivity in CRAC channels is not hardwired into Orai proteins, but is instead manifested only following the binding of STIM1 to the intrinsically poorly Ca(2+)-selective Orai channels. These findings reveal new functional aspects of CRAC channels and suggest that the selectivity filter of the CRAC channel is a dynamic structure whose conformation and functional properties are powerfully regulated by the channel activation stimulus.
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Affiliation(s)
- Beth A McNally
- Department of Molecular Pharmacology and Biological Chemistry, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
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203
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López E, Salido GM, Rosado JA, Berna-Erro A. Unraveling STIM2 function. J Physiol Biochem 2012; 68:619-33. [PMID: 22477146 DOI: 10.1007/s13105-012-0163-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 03/13/2012] [Indexed: 12/11/2022]
Abstract
The discovery of molecular players in capacitative calcium (Ca(2+)) entry, also referred to as store-operated Ca(2+) entry (SOCE), supposed a great advance in the knowledge of cellular mechanisms of Ca(2+) entry, which are essential for a broad range of cellular functions. The identification of STIM1 and STIM2 proteins as the sensors of Ca(2+) stored in the endoplasmic reticulum unraveled the mechanism by which depletion of intracellular Ca(2+) stores is communicated to store-operated Ca(2+) channels located in the plasma membrane, triggering the activation of SOCE and intracellular Ca(2+)-dependent signaling cascades. Initial studies suggested a dominant function of STIM1 in SOCE and SOCE-dependent cellular functions compared to STIM2, especially those that participate in immune responses. Consequently, most of the subsequent studies focused on STIM1. However, during the last years, STIM2 has been demonstrated to play a more relevant and complex function than initially reported, being even important to sustain normal life in mice. These studies have led to reconsider the role of STIM2 in SOCE and its relevance in cellular physiology. This review is intended to summarize and provide an overview of the current data available about this exciting isoform, STIM2, and its actual position together with STIM1 in the mechanism of SOCE.
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Affiliation(s)
- Esther López
- Department of Physiology (Cellular Physiology Research Group), University of Extremadura, Av. Universidad s/n, 10003, Cáceres, Spain
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204
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Stanisz H, Stark A, Kilch T, Schwarz EC, Müller CSL, Peinelt C, Hoth M, Niemeyer BA, Vogt T, Bogeski I. ORAI1 Ca(2+) channels control endothelin-1-induced mitogenesis and melanogenesis in primary human melanocytes. J Invest Dermatol 2012; 132:1443-51. [PMID: 22318387 DOI: 10.1038/jid.2011.478] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
UV radiation of the skin triggers keratinocytes to secrete endothelin-1 (ET-1) that binds to endothelin receptors on neighboring melanocytes. Melanocytes respond with a prolonged increase in intracellular Ca(2+) concentration ([Ca(2+)](i)), which is necessary for proliferation and melanogenesis. A major fraction of the Ca(2+) signal is caused by entry through Ca(2+)-permeable channels of unknown identity in the plasma membrane. ORAI Ca(2+) channels are molecular determinants of Ca(2+) release-activated Ca(2+) (CRAC) channels and are expressed in many tissues. Here, we show that ORAI1-3 and their activating partners stromal interaction molecules 1 and 2 (STIM1 and STIM2) are expressed in human melanocytes. Although ORAI1 is the predominant ORAI isoform, STIM2 mRNA expression exceeds STIM1. Inhibition of ORAI1 by 2-aminoethoxydiphenyl borate (2-APB) or downregulation of ORAI1 by small interfering RNA (siRNA) reduced Ca(2+) entry and CRAC current amplitudes in activated melanocytes. In addition, suppression of ORAI1 caused reduction in the ET-1-induced cellular viability, melanin synthesis, and tyrosinase activity. Our results imply a role for ORAI1 channels in skin pigmentation and their potential involvement in UV-induced stress responses of the human skin.
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Affiliation(s)
- Hedwig Stanisz
- Department of Dermatology, Venerology and Allergology, University Hospital of the Saarland, Homburg, Germany.
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205
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McNally BA, Somasundaram A, Yamashita M, Prakriya M. Gated regulation of CRAC channel ion selectivity by STIM1. Nature 2012; 482:241-5. [PMID: 22278058 PMCID: PMC3276717 DOI: 10.1038/nature10752] [Citation(s) in RCA: 179] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Accepted: 12/02/2011] [Indexed: 12/31/2022]
Abstract
Two defining functional features of ion channels are ion selectivity and channel gating. Ion selectivity is generally considered an immutable property of the open channel structure, whereas gating involves transitions between open and closed channel states typically without changes in ion selectivity 1. In store-operated Ca2+ release-activated Ca2+ (CRAC) channels, the molecular mechanism of channel gating by the CRAC channel activator, STIM1 (stromal interaction molecule 1) remains unknown. CRAC channels are distinguished by an extraordinarily high Ca2+ selectivity and are instrumental in generating sustained [Ca2+]i elevations necessary for gene expression and effector function in many eukaryotic cells 2. Here, we probed the central features of the STIM1 gating mechanism in the CRAC channel protein, Orai1, and identified V102, a residue located in the extracellular region of the pore, as a candidate for the channel gate. Mutations at V102 produced constitutively active CRAC channels that were open even in the absence of STIM1. Unexpectedly, although STIM1-free V102 mutant channels were not Ca2+-selective, their Ca2+ selectivity was dose-dependently boosted by interactions with STIM1. Similar enhancement of Ca2+ selectivity also occurred in wild-type (WT) Orai1 channels by increasing the number of STIM1 activation domains directly tethered to Orai1 channels. Thus, exquisite Ca2+ selectivity is not an intrinsic property of CRAC channels, but rather a tunable feature bestowed on otherwise non-selective Orai1 channels by STIM1. Our results demonstrate that STIM1-mediated gating of CRAC channels occurs through an unusual mechanism wherein permeation and gating are closely coupled.
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Affiliation(s)
- Beth A McNally
- Department of Molecular Pharmacology and Biological Chemistry, Northwestern University School of Medicine, 303 E Chicago Avenue, Ward 8-296, Chicago, Illinois 60611, USA
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206
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Structure, regulation and biophysics of I(CRAC), STIM/Orai1. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 740:383-410. [PMID: 22453951 DOI: 10.1007/978-94-007-2888-2_16] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Ca(2+) release activated Ca(2+) (CRAC) channels mediate robust Ca(2+) influx when the endoplasmic reticulum Ca(2+) stores are depleted. This essential process for T-cell activation as well as degranulation of mast cells involves the Ca(2+) sensor STIM1, located in the endoplasmic reticulum and the Ca(2+) selective Orai1 channel in the plasma membrane. Our review describes the CRAC signaling pathway, the activation of which is initiated by a drop in the endoplasmic Ca(2+) level sensed by STIM1. This in term induces multimerisation and puncta-formation of STIM1 proteins is followed by their coupling to and activation of Orai channels. Consequently Ca(2+) entry is triggered through the Orai pore into the cytosol with subsequent closure of the channel by Ca(2+)-dependent inactivation. We will portray a mechanistic view of the events coupling STIM1 to Orai activation based on their structure and biophysics.
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207
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Feng M. Calcium Imaging. Bio Protoc 2012. [DOI: 10.21769/bioprotoc.200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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208
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Falconer C, Kenny PA, Smart CE, Monteith GR, Roberts-Thomson SJ. Peroxisome proliferator-activated receptor subtypes in mammary gland development and breast cancer. ACTA ACUST UNITED AC 2012. [DOI: 10.7243/2049-7962-1-14] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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209
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Structural evolution and tissue-specific expression of tetrapod-specific second isoform of secretory pathway Ca2+-ATPase. Biochem Biophys Res Commun 2012; 417:1298-303. [DOI: 10.1016/j.bbrc.2011.12.135] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 12/25/2011] [Indexed: 11/19/2022]
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210
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Micaroni M. Calcium around the Golgi apparatus: implications for intracellular membrane trafficking. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 740:439-60. [PMID: 22453953 DOI: 10.1007/978-94-007-2888-2_18] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
As with other complex cellular functions, intracellular membrane transport involves the coordinated engagement of a series of organelles and machineries; in the last couple of decades more importance has been given to the role of calcium (Ca(2+)) in the regulation of membrane trafficking, which is directly involved in coordinating the endoplasmic reticulum-to-Golgi-to-plasma membrane delivery of cargo. Consequently, the Golgi apparatus (GA) is now considered not just the place proteins mature in as they move to their final destination(s), but it is increasingly viewed as an intracellular Ca(2+) store. In the last few years the mechanisms regulating the homeostasis of Ca(2+) in the GA and its role in membrane trafficking have begun to be elucidated. Here, these recent discoveries that shed light on the role Ca(2+) plays as of trigger of different steps during membrane trafficking has been reviewed. This includes recruitment of proteins and SNARE cofactors to the Golgi membranes, which are both fundamental for the membrane remodeling and the regulation of fusion/fission events occurring during the passage of cargo across the GA. I conclude by focusing attention on Ca(2+) homeostasis dysfunctions in the GA and their related pathological implications.
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Affiliation(s)
- Massimo Micaroni
- Division of Molecular Cell Biology, Institute for Molecular Bioscience, The University of Queensland, 306 Carmody Road, 4072 Brisbane, St. Lucia, QLD, Australia.
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211
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Martín-Romero FJ, López-Guerrero AM, Álvarez IS, Pozo-Guisado E. Role of Store-Operated Calcium Entry During Meiotic Progression and Fertilization of Mammalian Oocytes. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2012; 295:291-328. [DOI: 10.1016/b978-0-12-394306-4.00014-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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212
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Antigny F, Girardin N, Frieden M. Transient receptor potential canonical channels are required for in vitro endothelial tube formation. J Biol Chem 2011; 287:5917-27. [PMID: 22203682 DOI: 10.1074/jbc.m111.295733] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
In endothelial cells Ca(2+) entry is an essential component of the Ca(2+) signal that takes place during processes such as cell proliferation or angiogenesis. Ca(2+) influx occurs via the store-operated Ca(2+) entry pathway, involving stromal interaction molecule-1 (STIM1) and Orai1, but also through channels gated by second messengers like the transient receptor potential canonical (TRPC) channels. The human umbilical vein-derived endothelial cell line EA.hy926 expressed STIM1 and Orai1 as well as several TRPC channels. By invalidating each of these molecules, we showed that TRPC3, TRPC4, and TRPC5 are essential for the formation of tubular structures observed after EA.hy926 cells were plated on Matrigel. On the contrary, the silencing of STIM1 or Orai1 did not prevent tubulogenesis. Soon after being plated on Matrigel, the cells displayed spontaneous Ca(2+) oscillations that were strongly reduced by treatment with siRNA against TRPC3, TRPC4, or TRPC5, but not siRNA against STIM1 or Orai1. Furthermore, we showed that cell proliferation was reduced upon siRNA treatment against TRPC3, TRPC5, and Orai1 channels, whereas the knockdown of STIM1 had no effect. On primary human umbilical vein endothelial cells, TRPC1, TRPC4, and STIM1 are involved in tube formation, whereas Orai1 has no effect. These data showed that TRPC channels are essential for in vitro tubulogenesis, both on endothelial cell line and on primary endothelial cells.
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Affiliation(s)
- Fabrice Antigny
- Department of Cell Physiology and Metabolism, Geneva Medical Center, 1 rue Michel Servet, 1211 Geneva 4, Switzerland
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213
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βig-h3 regulates store-operated Ca2+ entry and promotes the invasion of human hepatocellular carcinoma cells. Cell Biol Int 2011; 35:811-7. [PMID: 21395558 DOI: 10.1042/cbi20100916] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
βig-h3 is a TGF-β (transforming growth factor β)-induced ECM (extracellular matrix) protein that induces the secretion of MMPs (matrix metalloproteinases). However, the mechanism of induction is yet to be established. In this study, siRNAs (small interfering RNAs) targeted against βig-h3 were transfected into SMMC-7721 cells [a HCC (human hepatocellular carcinoma) cell line] to knockdown the expression of βig-h3. We found that NiCl2, a potent blocker of extracellular Ca2+ entry, reduced βig-h3-induced secretion of MMP-2 and -9. Further investigation suggested that reduction in the levels of βig-h3 decreased the secretion of MMP-2 and -9 that was enhanced by an increase in the concentration of extracellular Ca2+. SNAP (S-nitroso-N-acetylpenicillamine), a NO (nitric oxide) donor, and 8-Br-cGMP (8-bromo-cGMP) inhibited thapsigargin-induced Ca2+ entry and MMP secretion in the invasive potential of human SMMC-7721 cells. Further, the inhibitory effects of 8-Br-cGMP and SNAP could be significantly enhanced by down-regulating βig-h3. βig-h3 attenuates the negative regulation of NO/cGMP-sensitive store-operated Ca2+ entry. Our findings suggest that the expression of βig-h3 might play an important role in the regulation of store-operated Ca2+ entry to increase the invasive potential of HCC cells.
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214
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Caldas J, Gehlenborg N, Kettunen E, Faisal A, Rönty M, Nicholson AG, Knuutila S, Brazma A, Kaski S. Data-driven information retrieval in heterogeneous collections of transcriptomics data links SIM2s to malignant pleural mesothelioma. ACTA ACUST UNITED AC 2011; 28:246-53. [PMID: 22106335 PMCID: PMC3259436 DOI: 10.1093/bioinformatics/btr634] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Motivation: Genome-wide measurement of transcript levels is an ubiquitous tool in biomedical research. As experimental data continues to be deposited in public databases, it is becoming important to develop search engines that enable the retrieval of relevant studies given a query study. While retrieval systems based on meta-data already exist, data-driven approaches that retrieve studies based on similarities in the expression data itself have a greater potential of uncovering novel biological insights. Results: We propose an information retrieval method based on differential expression. Our method deals with arbitrary experimental designs and performs competitively with alternative approaches, while making the search results interpretable in terms of differential expression patterns. We show that our model yields meaningful connections between biological conditions from different studies. Finally, we validate a previously unknown connection between malignant pleural mesothelioma and SIM2s suggested by our method, via real-time polymerase chain reaction in an independent set of mesothelioma samples. Availability:Supplementary data and source code are available from http://www.ebi.ac.uk/fg/research/rex. Contact:samuel.kaski@aalto.fi Supplementary Information:Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- José Caldas
- Helsinki Institute for Information Technology HIIT, Department of Information and Computer Science, Aalto University, Helsinki, Finland
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215
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Giachini FR, Lima VV, Hannan JL, Carneiro FS, Webb RC, Tostes RC. STIM1/Orai1-mediated store-operated Ca2+ entry: the tip of the iceberg. Braz J Med Biol Res 2011; 44:1080-7. [PMID: 22002090 DOI: 10.1590/s0100-879x2011007500133] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Accepted: 09/05/2011] [Indexed: 11/22/2022] Open
Abstract
Highly efficient mechanisms regulate intracellular calcium (Ca2+) levels. The recent discovery of new components linking intracellular Ca2+ stores to plasma membrane Ca2+ entry channels has brought new insight into the understanding of Ca2+ homeostasis. Stromal interaction molecule 1 (STIM1) was identified as a Ca2+ sensor essential for Ca2+ store depletion-triggered Ca2+ influx. Orai1 was recognized as being an essential component for the Ca2+ release-activated Ca2+ (CRAC) channel. Together, these proteins participate in store-operated Ca2+ channel function. Defective regulation of intracellular Ca2+ is a hallmark of several diseases. In this review, we focus on Ca2+ regulation by the STIM1/Orai1 pathway and review evidence that implicates STIM1/Orai1 in several pathological conditions including cardiovascular and pulmonary diseases, among others.
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Affiliation(s)
- F R Giachini
- Department of Physiology, Georgia Heath Science University, Augusta, GA, USA.
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216
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Le Deist F, Capiod T. Immunodéficiences et pathologies associées aux mutations dans STIM/ORAI. Med Sci (Paris) 2011; 27:737-45. [DOI: 10.1051/medsci/2011278016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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217
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Calcium store sensor stromal-interaction molecule 1-dependent signaling plays an important role in cervical cancer growth, migration, and angiogenesis. Proc Natl Acad Sci U S A 2011; 108:15225-30. [PMID: 21876174 DOI: 10.1073/pnas.1103315108] [Citation(s) in RCA: 268] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Store-operated Ca(2+) entry (SOCE) is the principal Ca(2+) entry mechanism in nonexcitable cells. Stromal-interaction molecule 1 (STIM1) is an endoplasmic reticulum Ca(2+) sensor that triggers SOCE activation. However, the role of STIM1 in regulating cancer progression remains controversial and its clinical relevance is unclear. Here we show that STIM1-dependent signaling is important for cervical cancer cell proliferation, migration, and angiogenesis. STIM1 overexpression in tumor tissue is noted in 71% cases of early-stage cervical cancer. In tumor tissues, the level of STIM1 expression is significantly associated with the risk of metastasis and survival. EGF-stimulated cancer cell migration requires STIM1 expression and EGF increases the interaction between STIM1 and Orai1 in juxta-membrane areas, and thus induces Ca(2+) influx. STIM1 involves the activation of Ca(2+)-regulated protease calpain, as well as Ca(2+)-regulated cytoplasmic kinase Pyk2, which regulate the focal-adhesion dynamics of migratory cervical cancer cells. Because of an increase of p21 protein levels and a decrease of Cdc25C protein levels, STIM1-silencing in cervical cancer cells significantly inhibits cell proliferation by arresting the cell cycle at the S and G2/M phases. STIM1 also regulates the production of VEGF in cervical cancer cells. Interference with STIM1 expression or blockade of SOCE activity inhibits tumor angiogenesis and growth in animal models, confirming the crucial role of STIM1-mediated Ca(2+) influx in aggravating tumor development in vivo. These results make STIM1-dependent signaling an attractive target for therapeutic intervention.
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218
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Ca2+ signalling in the Golgi apparatus. Cell Calcium 2011; 50:184-92. [DOI: 10.1016/j.ceca.2011.01.006] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Revised: 01/11/2011] [Accepted: 01/12/2011] [Indexed: 11/20/2022]
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219
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Affiliation(s)
- Maike Bublitz
- Centre for Membrane Pumps in Cells and Disease – PUMPKIN, Danish National Research Foundation, Department of Molecular Biology, Aarhus University, Gustav Wieds Vej 10C, DK-8000 Aarhus C, Denmark
- Department of Molecular Biology, University of Aarhus, Gustav Wieds Vej 10C, DK-8000 Aarhus, Denmark
| | - J. Preben Morth
- Centre for Molecular Medicine Norway, Nordic EMBL Partnership, University of Oslo, P.O. Box 1125, Blindern, N-0318 Oslo, Norway
- Institute for Experimental Medical Research, Oslo University Hospital Ullevaal, N-0407 Oslo, Norway
| | - Poul Nissen
- Centre for Membrane Pumps in Cells and Disease – PUMPKIN, Danish National Research Foundation, Department of Molecular Biology, Aarhus University, Gustav Wieds Vej 10C, DK-8000 Aarhus C, Denmark
- Department of Molecular Biology, University of Aarhus, Gustav Wieds Vej 10C, DK-8000 Aarhus, Denmark
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220
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Capiod T. Cell proliferation, calcium influx and calcium channels. Biochimie 2011; 93:2075-9. [PMID: 21802482 DOI: 10.1016/j.biochi.2011.07.015] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Accepted: 07/12/2011] [Indexed: 01/14/2023]
Abstract
Both increases in the basal cytosolic calcium concentration ([Ca(2+)](cyt)) and [Ca(2+)](cyt) transients play major roles in cell cycle progression, cell proliferation and division. Calcium transients are observed at various stages of cell cycle and more specifically during late G(1) phase, before and during mitosis. These calcium transients are mainly due to calcium release and reuptake by the endoplasmic reticulum (ER) and are observed over periods of hours in oocytes and mammalian cells. Calcium entry sustains the ER Ca(2+) load and thereby helps to maintain these calcium transients for such a long period. Calcium influx also controls cell growth and proliferation in several cell types. Various calcium channels are involved in this process and the tight relation between the expression and activity of cyclins and calcium channels also suggests that calcium entry may be needed only at particular stages of the cell cycle. Consistent with this idea, the expression of l-type and T-type calcium channels and SOCE amplitude fluctuate along the cell cycle. But, as calcium influx regulates several other transduction pathways, the presence of a specific connection to trigger activation of proliferation and cell division in mammalian cells will be discussed in this review.
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Affiliation(s)
- Thierry Capiod
- INSERM U807, Faculté de Médecine, 156 rue de Vaugirard, Paris, France.
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221
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Abstract
In most cases, metastasis, not the primary tumour per se, is the main cause of mortality in cancer patients. In order to effectively escape the tumour, enter the circulation and establish secondary growth in distant organs cancer cells must develop an enhanced propensity to migrate. The ubiquitous second messenger Ca²⁺ is a crucial regulator of cell migration. Recently, a number of known molecular players in cellular Ca²⁺ homeostasis, including calcium release-activated calcium channel protein 1 (ORAI1), stromal interaction molecule 1 (STIM1) and transient receptor potential (TRP) channels, have been implicated in tumour cell migration and the metastatic cell phenotype. We discuss how these developments have increased our understanding of the Ca²⁺ dependence of pro-metastatic behaviours.
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Affiliation(s)
- Natalia Prevarskaya
- INSERM, U1003, Laboratoire de Physiologie Cellulaire, Equipe labellise par la Ligue contre le cancer, Villeneuve dAscq, F59650, France.
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222
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ADF/cofilin regulates secretory cargo sorting at the TGN via the Ca2+ ATPase SPCA1. Dev Cell 2011; 20:652-62. [PMID: 21571222 DOI: 10.1016/j.devcel.2011.03.014] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Revised: 02/22/2011] [Accepted: 03/15/2011] [Indexed: 01/08/2023]
Abstract
Actin-severing proteins ADF/cofilin are required for the sorting of secretory cargo at the trans-Golgi network (TGN) in mammalian cells. How do these cytoplasmic proteins interact with the cargoes in the lumen of the TGN? Put simply, how are these two sets of proteins connected across the TGN membrane? Mass spectrometry of cofilin1 immunoprecipitated from HeLa cells revealed the presence of actin and the Ca(2+) ATPase SPCA1. Moreover, cofilin1 was localized to the TGN and bound to SPCA1 via dynamic actin. SPCA1 knockdown, like ADF/cofilin1 knockdown, inhibited Ca(2+) uptake into the TGN and caused missorting of secretory cargo. These defects were rescued by the overexpression of the TGN-localized SPCA1. We propose that ADF/cofilin-dependent severing of actin filaments exposes and promotes the activation of SPCA1, which pumps Ca(2+) into the lumen of the TGN for the sorting of the class of secretory cargo that binds Ca(2+).
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223
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Lee JM, Davis FM, Roberts-Thomson SJ, Monteith GR. Ion channels and transporters in cancer. 4. Remodeling of Ca(2+) signaling in tumorigenesis: role of Ca(2+) transport. Am J Physiol Cell Physiol 2011; 301:C969-76. [PMID: 21593447 DOI: 10.1152/ajpcell.00136.2011] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The Ca(2+) signal has major roles in cellular processes important in tumorigenesis, including migration, invasion, proliferation, and apoptotic sensitivity. New evidence has revealed that, aside from altered expression and effects on global cytosolic free Ca(2+) levels via direct transport of Ca(2+), some Ca(2+) pumps and channels are able to contribute to tumorigenesis via mechanisms that are independent of their ability to transport Ca(2+) or effect global Ca(2+) homeostasis in the cytoplasm. Here, we review some of the most recent studies that present evidence of altered Ca(2+) channel or pump expression in tumorigenesis and discuss the importance and complexity of localized Ca(2+) signaling in events critical for tumor formation.
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Affiliation(s)
- Jane M Lee
- School of Pharmacy, The University of Queensland, Brisbane, Queensland, Australia
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Kiviluoto S, Decuypere JP, De Smedt H, Missiaen L, Parys JB, Bultynck G. STIM1 as a key regulator for Ca2+ homeostasis in skeletal-muscle development and function. Skelet Muscle 2011; 1:16. [PMID: 21798093 PMCID: PMC3156639 DOI: 10.1186/2044-5040-1-16] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Accepted: 04/04/2011] [Indexed: 12/17/2022] Open
Abstract
Stromal interaction molecules (STIM) were identified as the endoplasmic-reticulum (ER) Ca2+ sensor controlling store-operated Ca2+ entry (SOCE) and Ca2+-release-activated Ca2+ (CRAC) channels in non-excitable cells. STIM proteins target Orai1-3, tetrameric Ca2+-permeable channels in the plasma membrane. Structure-function analysis revealed the molecular determinants and the key steps in the activation process of Orai by STIM. Recently, STIM1 was found to be expressed at high levels in skeletal muscle controlling muscle function and properties. Novel STIM targets besides Orai channels are emerging.Here, we will focus on the role of STIM1 in skeletal-muscle structure, development and function. The molecular mechanism underpinning skeletal-muscle physiology points toward an essential role for STIM1-controlled SOCE to drive Ca2+/calcineurin/nuclear factor of activated T cells (NFAT)-dependent morphogenetic remodeling programs and to support adequate sarcoplasmic-reticulum (SR) Ca2+-store filling. Also in our hands, STIM1 is transiently up-regulated during the initial phase of in vitro myogenesis of C2C12 cells. The molecular targets of STIM1 in these cells likely involve Orai channels and canonical transient receptor potential (TRPC) channels TRPC1 and TRPC3. The fast kinetics of SOCE activation in skeletal muscle seem to depend on the triad-junction formation, favoring a pre-localization and/or pre-formation of STIM1-protein complexes with the plasma-membrane Ca2+-influx channels. Moreover, Orai1-mediated Ca2+ influx seems to be essential for controlling the resting Ca2+ concentration and for proper SR Ca2+ filling. Hence, Ca2+ influx through STIM1-dependent activation of SOCE from the T-tubule system may recycle extracellular Ca2+ losses during muscle stimulation, thereby maintaining proper filling of the SR Ca2+ stores and muscle function. Importantly, mouse models for dystrophic pathologies, like Duchenne muscular dystrophy, point towards an enhanced Ca2+ influx through Orai1 and/or TRPC channels, leading to Ca2+-dependent apoptosis and muscle degeneration. In addition, human myopathies have been associated with dysfunctional SOCE. Immunodeficient patients harboring loss-of-function Orai1 mutations develop myopathies, while patients suffering from Duchenne muscular dystrophy display alterations in their Ca2+-handling proteins, including STIM proteins. In any case, the molecular determinants responsible for SOCE in human skeletal muscle and for dysregulated SOCE in patients of muscular dystrophy require further examination.
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Affiliation(s)
- Santeri Kiviluoto
- Laboratory of Molecular and Cellular Signaling, Department Molecular Cell Biology, K,U, Leuven, Campus Gasthuisberg O/N-1 bus 802, Herestraat 49, BE-3000 Leuven, Belgium
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225
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Leitch S, Feng M, Muend S, Braiterman LT, Hubbard AL, Rao R. Vesicular distribution of Secretory Pathway Ca²+-ATPase isoform 1 and a role in manganese detoxification in liver-derived polarized cells. Biometals 2011; 24:159-70. [PMID: 20981470 PMCID: PMC3238027 DOI: 10.1007/s10534-010-9384-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Accepted: 10/13/2010] [Indexed: 12/24/2022]
Abstract
Manganese is a trace element that is an essential co-factor in many enzymes critical to diverse biological pathways. However, excess Mn(2+) leads to neurotoxicity, with psychiatric and motor dysfunction resembling parkinsonism. The liver is the main organ for Mn(2+) detoxification by excretion into bile. Although many pathways of cellular Mn(2+) uptake have been established, efflux mechanisms remain essentially undefined. In this study, we evaluated a potential role in Mn(2+) detoxification by the Secretory Pathway Ca(2+), Mn(2+)-ATPase in rat liver and a liver-derived cell model WIF-B that polarizes to distinct bile canalicular and sinusoidal domains in culture. Of two known isoforms, only secretory pathway Ca(2+)-ATPase isoform 1 (SPCA1) was expressed in liver and WIF-B cells. As previously observed in non-polarized cells, SPCA1 showed overlapping distribution with TGN38, consistent with Golgi/TGN localization. However, a prominent novel localization of SPCA1 to an endosomal population close to, but not on the basolateral membrane was also observed. This was confirmed by fractionation of rat liver homogenates which revealed dual distribution of SPCA1 to the Golgi/TGN and a fraction that included the early endosomal marker, EEA1. We suggest that this novel pool of endosomes may serve to sequester Mn(2+) as it enters from the sinusoidal/basolateral domains. Isoform-specific partial knockdown of SPCA1 delayed cell growth and formation of canalicular domain by about 30% and diminished viability upon exposure to Mn(2+). Conversely, overexpression of SPCA1 in HEK 293T cells conferred tolerance to Mn(2+) toxicity. Taken together, our findings suggest a role for SPCA1 in Mn(2+) detoxification in liver.
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Affiliation(s)
- Sharon Leitch
- Department of Physiology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
| | - Mingye Feng
- Department of Physiology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
| | - Sabina Muend
- Department of Physiology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
| | | | - Ann L. Hubbard
- Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Rajini Rao
- Department of Physiology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
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226
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McAndrew D, Grice DM, Peters AA, Davis FM, Stewart T, Rice M, Smart CE, Brown MA, Kenny PA, Roberts-Thomson SJ, Monteith GR. ORAI1-mediated calcium influx in lactation and in breast cancer. Mol Cancer Ther 2011; 10:448-60. [PMID: 21224390 DOI: 10.1158/1535-7163.mct-10-0923] [Citation(s) in RCA: 170] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The entry of calcium into the mammary epithelial cell from the maternal plasma (i.e., calcium influx mechanisms) during lactation is poorly understood. As alterations in calcium channels and pumps are a key feature of some cancers, including breast cancer, understanding these calcium influx pathways may have significance beyond mammary biology. We show that the store-operated calcium influx protein, Orai1, is increased during lactation whereas the Orai1 activator Stim1, but not Stim2, is downregulated. Stim2 siRNA reduced basal calcium levels in a lactation model. Our results suggest that calcium influx is remodeled in mammary epithelial cells during lactation, with calcium influx increased through Orai1, activated by Stim2. Breast cancer cell lines had increased levels of ORAI1. ORAI1 siRNA in breast cancer cells reduced store-operated calcium entry and remodeled the calcium influx associated with invasive stimuli. Analysis of microarray data from 295 breast cancers showed that the transcriptional breast cancer subtype with the poorest prognosis (basal) was associated with an altered relationship between the ORAI1 regulators STIM1 and STIM2, and that women with breast cancers with STIM1(high)/STIM2(low) tumors had a significantly poorer prognosis. Our studies show that during lactation there is a remodeling in the nature of calcium influx and that alteration in the ORAI1 influx pathway may be a feature of some breast cancers, particularly those with the poorest prognosis. Our studies suggest that this pathway may be a novel therapeutic target for breast cancer treatment in these women.
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Affiliation(s)
- Damara McAndrew
- School of Pharmacy, The University of Queensland, Brisbane, Queensland Australia, 4072
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227
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Yamashita M, Somasundaram A, Prakriya M. Competitive modulation of Ca2+ release-activated Ca2+ channel gating by STIM1 and 2-aminoethyldiphenyl borate. J Biol Chem 2010; 286:9429-42. [PMID: 21193399 DOI: 10.1074/jbc.m110.189035] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Activation of Ca(2+) release-activated Ca(2+) channels by depletion of intracellular Ca(2+) stores involves physical interactions between the endoplasmic reticulum Ca(2+) sensor, STIM1, and the channels composed of Orai subunits. Recent studies indicate that the Orai3 subtype, in addition to being store-operated, is also activated in a store-independent manner by 2-aminoethyldiphenyl borate (2-APB), a small molecule with complex pharmacology. However, it is unknown whether the store-dependent and -independent activation modes of Orai3 channels operate independently or whether there is cross-talk between these activation states. Here we report that in addition to causing direct activation, 2-APB also regulates store-operated gating of Orai3 channels, causing potentiation at low doses and inhibition at high doses. Inhibition of store-operated gating by 2-APB was accompanied by the suppression of several modes of Orai3 channel regulation that depend on STIM1, suggesting that high doses of 2-APB interrupt STIM1-Orai3 coupling. Conversely, STIM1-bound Orai3 (and Orai1) channels resisted direct gating by high doses of 2-APB. The rate of direct 2-APB activation of Orai3 channels increased linearly with the degree of STIM1-Orai3 uncoupling, suggesting that 2-APB has to first disengage STIM1 before it can directly gate Orai3 channels. Collectively, our results indicate that the store-dependent and -independent modes of Ca(2+) release-activated Ca(2+) channel activation are mutually exclusive: channels bound to STIM1 resist 2-APB gating, whereas 2-APB antagonizes STIM1 gating.
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Affiliation(s)
- Megumi Yamashita
- Department of Molecular Pharmacology and Biological Chemistry, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
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