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Priyodarshan Goswamee, Tamar Pounardjian, David R Giovannucci
Background: Store-operated Ca2+ entry (SOCE) has been implicated in the migration of some cancer cell lines. The canonical SOCE is defined as the Ca2+ entry that occurs in response to near-maximal depletion of Ca2+ within the endoplasmic reticulum. Alternatively, arachidonic acid (AA) has been shown to induce Ca2+ entry in a store-independent manner through Orai1/Orai3 hetero-multimeric channels. However, the role of this AA-induced Ca2+ entry pathway in cancer cell migration has not been adequately assessed...
2018: Cancer Cell International
Jun Wu, Daniel Ryskamp, Lutz Birnbaumer, Ilya Bezprozvanny
BACKGROUND: Huntington disease (HD) is a dominantly inherited neurodegenerative disorder caused by a CAG repeat expansion in the huntingtin gene. We previously discovered that mutant Huntingtin sensitizes type 1 inositol 1,4,5-trisphosphate receptor (InsP3R1) to InsP3. This causes calcium leakage from the endoplasmic reticulum (ER) and a compensatory increase in neuronal store-operated calcium (nSOC) entry. We previously demonstrated that supranormal nSOC leads to synaptic loss in striatal medium spiny neurons (MSNs) in YAC128 HD mice...
2018: Journal of Huntington's Disease
Nguyen Thi Xuan, Nong Van Hai
Klotho (KL) encodes a single-pass transmembrane protein and is predominantly expressed in the kidney, parathyroid glands, and choroid plexus. Genetic studies on the KL gene have revealed that DNA hypermethylation is one of the major risk factors for aging, diseases, and cancer. Besides, KL exerts anti-inflammatory and anti-tumor effects by regulating signaling pathways and the expression of target genes. KL participates in modulation of the insulin/insulin-like growth factor-1 (IGF-1) signaling, which induces the growth hormone (GH) secretion...
January 2018: Iranian Journal of Basic Medical Sciences
Jessy Hasna, Frédéric Hague, Lise Rodat-Despoix, Dirk Geerts, Catherine Leroy, David Tulasne, Halima Ouadid-Ahidouch, Philippe Kischel
Orai proteins are highly selective calcium channels playing an important role in calcium entry. Orai3 channels are overexpressed in breast cancer (BC) tissues, and involved in their proliferation, cell cycle progression and survival. Herein, we sought to address the involvement of Orai3 in resistance to chemotherapeutic drugs. Using high-throughput approaches, we investigated major changes induced by Orai3 overexpression, including downstream signaling mechanisms involved in BC chemotherapy resistance. Resistance was dependent on external calcium presence and thus Orai3 functionality...
January 11, 2018: Cell Death and Differentiation
Isabella Derler, Carmen Butorac, Adéla Krizova, Michael Stadlbauer, Martin Muik, Marc Fahrner, Irene Frischauf, Christoph Romanin
Calcium (Ca2+ ) is an essential second messenger required for diverse signaling processes in immune cells. Ca2+ release-activated Ca2+ (CRAC) channels represent one main Ca2+ entry pathway into the cell. They are fully reconstituted via two proteins, the stromal interaction molecule 1 (STIM1), a Ca2+ sensor in the endoplasmic reticulum, and the Ca2+ ion channel Orai in the plasma membrane. After Ca2+ store depletion, STIM1 and Orai couple to each other, allowing Ca2+ influx. CRAC-/STIM1-mediated Orai channel currents display characteristic hallmarks such as high Ca2+ selectivity, an increase in current density when switching from a Ca2+ -containing solution to a divalent-free Na+ one, and fast Ca2+ -dependent inactivation...
January 26, 2018: Journal of Biological Chemistry
Marc Fahrner, Saurabh K Pandey, Martin Muik, Lukas Traxler, Carmen Butorac, Michael Stadlbauer, Vasilina Zayats, Adéla Krizova, Peter Plenk, Irene Frischauf, Rainer Schindl, Hermann J Gruber, Peter Hinterdorfer, Rüdiger Ettrich, Christoph Romanin, Isabella Derler
Ca2+ release-activated Ca2+ (CRAC) channels constitute the major Ca2+ entry pathway into the cell. They are fully reconstituted via intermembrane coupling of the Ca2+ -selective Orai channel and the Ca2+ -sensing protein STIM1. In addition to the Orai C terminus, the main coupling site for STIM1, the Orai N terminus is indispensable for Orai channel gating. Although the extended transmembrane Orai N-terminal region (Orai1 amino acids 73-91; Orai3 amino acids 48-65) is fully conserved in the Orai1 and Orai3 isoforms, Orai3 tolerates larger N-terminal truncations than Orai1 in retaining store-operated activation...
January 26, 2018: Journal of Biological Chemistry
Jian Wang, Chuyi Xu, Qiuyu Zheng, Kai Yang, Ning Lai, Tao Wang, Haiyang Tang, Wenju Lu
Previous studies have demonstrated that besides the classic canonical transient receptor potential channel family, Orai family and stromal interaction molecule 1 (STIM1) might also be involved in the regulation of store-operated calcium channels (SOCCs). An increase in cytosolic free Ca2+ concentration promoted by store-operated Ca2+ entry (SOCE) in pulmonary arterial smooth muscle cells (PASMCs) is a major trigger for pulmonary vasoconstriction and proliferation and migration of PASMCs. In this study, our data revealed the following: (1) in both rat distal pulmonary arteries and PASMCs, chronic hypoxia exposure upregulated the expression of Orai1 and Orai2, without affecting Orai3 and STIM1; (2) either heterozygous knockout of HIF-1 α in mice or knockdown of HIF-1 α in PASMCs abolished the hypoxic upregulation of Orai2, but not Orai1, suggesting the hypoxic upregulation of Orai2 depends on HIF-1 α ; and (3) using small interference RNA knockdown strategies, Orai1, 2, 3 and STIM1 were all shown to mediate SOCE in hypoxic PASMCs...
2017: Cell Death Discovery
Jayson Lian, Mario Cuk, Sascha Kahlfuss, Lina Kozhaya, Martin Vaeth, Frédéric Rieux-Laucat, Capucine Picard, Melina J Benson, Antonia Jakovcevic, Karmen Bilic, Iva Martinac, Peter Stathopulos, Imre Kacskovics, Thomas Vraetz, Carsten Speckmann, Stephan Ehl, Thomas Issekutz, Derya Unutmaz, Stefan Feske
BACKGROUND: Store-operated Ca2+ entry (SOCE) through Ca2+ release-activated Ca2+ channels is an essential signaling pathway in many cell types. Ca2+ release-activated Ca2+ channels are formed by ORAI1, ORAI2, and ORAI3 proteins and activated by stromal interaction molecule (STIM) 1 and STIM2. Mutations in the ORAI1 and STIM1 genes that abolish SOCE cause a combined immunodeficiency (CID) syndrome that is accompanied by autoimmunity and nonimmunologic symptoms. OBJECTIVE: We performed molecular and immunologic analysis of patients with CID, anhidrosis, and ectodermal dysplasia of unknown etiology...
November 16, 2017: Journal of Allergy and Clinical Immunology
Lukas Traxler, Petr Rathner, Marc Fahrner, Michael Stadlbauer, Felix Faschinger, Tatsiana Charnavets, Norbert Müller, Christoph Romanin, Peter Hinterdorfer, Hermann J Gruber
Calmodulin (CaM) binds most of its targets by wrapping around an amphipathic α-helix. The N-terminus of Orai proteins contains a conserved CaM-binding segment but the binding mechanism has been only partially characterized. Here, microscale thermophoresis (MST), surface plasmon resonance (SPR), and atomic force microscopy (AFM) were employed to study the binding equilibria, the kinetics, and the single-molecule interaction forces involved in the binding of CaM to the conserved helical segments of Orai1 and Orai3...
December 4, 2017: Angewandte Chemie
Aparna Gudlur, Patrick G Hogan
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...
2017: Advances in Experimental Medicine and Biology
Jyoti Tanwar, Rajender K Motiani
Calcium (Ca(2+)) signaling plays a critical role in regulating plethora of cellular functions including cell survival, proliferation and migration. The perturbations in cellular Ca(2+) homeostasis can lead to cell death either by activating autophagic pathways or through induction of apoptosis. Endoplasmic reticulum (ER) is the major storehouse of Ca(2+) within cells and a number of physiological agonists mediate ER Ca(2+) release by activating IP3 receptors (IP3R). This decrease in ER Ca(2+) levels is sensed by STIM, which physically interacts and activates plasma membrane Ca(2+) selective Orai channels...
June 9, 2017: Cell Calcium
Jea Kwon, Heeyoung An, Moonsun Sa, Joungha Won, Jeong Im Shin, C Justin Lee
Astrocytes are non-excitable cells in the brain and their activity largely depends on the intracellular calcium (Ca(2+)) level. Therefore, maintaining the intracellular Ca(2+) homeostasis is critical for proper functioning of astrocytes. One of the key regulatory mechanisms of Ca(2+) homeostasis in astrocytes is the store-operated Ca(2+) entry (SOCE). This process is mediated by a combination of the Ca(2+)-store-depletion-sensor, Stim, and the store-operated Ca(2+)-channels, Orai and TrpC families. Despite the existence of all those families in astrocytes, previous studies have provided conflicting results on the molecular identification of astrocytic SOCE...
February 2017: Experimental Neurobiology
Daniel Leon-Aparicio, Jonathan Pacheco, Jesus Chavez-Reyes, Jose M Galindo, Jesus Valdes, Luis Vaca, Agustin Guerrero-Hernandez
We have studied in HeLa cells the molecular nature of the 2-APB induced ER Ca(2+) leak using synthetic Ca(2+) indicators that report changes in both the cytoplasmic ([Ca(2+)]i) and the luminal ER ([Ca(2+)]ER) Ca(2+) concentrations. We have tested the hypothesis that Orai channels participate in the 2-APB-induced ER Ca(2+) leak that was characterized in the companion paper. The expression of the dominant negative Orai1 E106A mutant, which has been reported to block the activity of all three types of Orai channels, inhibited the effect of 2-APB on the [Ca(2+)]ER but did not decrease the ER Ca(2+) leak after thapsigargin (TG)...
July 2017: Cell Calcium
Sylvain Chauvet, Louis Jarvis, Mireille Chevallet, Niroj Shrestha, Klaus Groschner, Alexandre Bouron
In the murine brain, the first post-mitotic cortical neurons formed during embryogenesis express store-operated channels (SOCs) sensitive to Pyr3, initially proposed as a blocker of the transient receptor potential channel of C type 3 (TRPC3 channel). However, Pyr3 does not discriminate between Orai and TRPC3 channels, questioning the contribution of TRPC3 in SOCs. This study was undertaken to clarify the molecular identity and the pharmacological profile of native SOCs from E13 cortical neurons. The mRNA expression of STIM1-2 and Orai1-3 was assessed by quantitative reverse transcription polymerase chain reaction...
2016: Frontiers in Pharmacology
Nazim Benzerdjeb, Henri Sevestre, Ahmed Ahidouch, Halima Ouadid-Ahidouch
Orai3 channel has emerged as important player in malignant transformation. Indeed, its expression is increased in cancer and favors cell proliferation and survival by permitting calcium influx. In this study, Orai3 was overexpressed in lung adenocarcinoma as compared to their matched non-tumour samples and was associated with tumoural aggressiveness. Moreover, its expression was associated with estrogen receptor alpha (ERα) expression and visceral pleural invasion in multivariate analysis. Furthermore, both the overall survival (OS) median and the metastasis free survival (MFS) median of tumors with high Orai3 expression were lower than in low Orai3 expression regardless of cancer stage (35...
December 6, 2016: Oncotarget
Susana Cubillos, Johannes Norgauer
Psoriasis is an inflammatory skin disease with or without joint involvement. In this disease, the thickened epidermis and impaired barrier are associated with altered calcium gradients. Calcium and vitamin D are known to play important roles in keratinocyte differentiation and bone metabolism. Intracellular calcium is regulated by calcium-sensing receptor (CASR), calcium release-activated calcium modulator (ORAI) and stromal interaction molecule (STIM). Other proteins modulated by vitamin D play important roles in calcium regulation e...
October 2016: International Journal of Molecular Medicine
Sumiko Denda, Kentaro Takei, Junichi Kumamoto, Makiko Goto, Mitsuhiro Denda
No abstract text is available yet for this article.
August 30, 2016: Experimental Dermatology
Letizia Albarrán, José J López, Luis J Gómez, Ginés M Salido, Juan A Rosado
Canonical transient receptor potential-1 (TRPC1) is an almost ubiquitously expressed channel that plays a relevant role in cell function. As other TRPC members, TRPC1 forms receptor-operated cation channels that exhibit both STIM1-dependent and store-independent behaviour. The STIM1 inhibitor SARAF (for store-operated Ca(2+) entry (SOCE)-associated regulatory factor) modulates SOCE by interaction with the STIM1 region responsible for Orai1 activation (SOAR). Furthermore, SARAF modulates Ca(2+) entry through the arachidonate-regulated Ca(2+) (ARC) channels, consisting of Orai1 and Orai3 heteropentamers and plasma membrane-resident STIM1...
October 15, 2016: Biochemical Journal
Francesco Moccia, Estella Zuccolo, Valentina Poletto, Ilaria Turin, Germano Guerra, Paolo Pedrazzoli, Vittorio Rosti, Camillo Porta, Daniela Montagna
An increase in intracellular Ca2+ concentration plays a key role in the establishment of many cancer hallmarks, including aberrant proliferation, migration, invasion, resistance to apoptosis and angiogenesis. The dysregulation of Ca2+ entry is one of the most subtle mechanisms by which cancer cells overwhelm their normal counterparts and gain the adaptive advantages that result in tumour growth, vascularisation and dissemination throughout the organism. Both constitutive and agonist-induced Ca2+ influx may be mediated by store-dependent as well as store-independent Ca2+ entry routes...
2016: Current Medicinal Chemistry
Rajesh Bhardwaj, Matthias A Hediger, Nicolas Demaurex
STIM1 and ORAI1 constitute the core machinery of the ubiquitous store-operated calcium entry pathway and loss of function in these proteins is associated with severe immune and muscular disorders. Other isoforms-STIM1L, STIM2, ORAI2 and ORAI3 exhibit varied expression levels in different cell types along with several other interaction partners and thereby play different roles to facilitate, regulate and fine-tune the calcium entry. STIM proteins convey the Ca(2+) store-depletion message to the PM and thereby participate in refilling of the ER by physically interacting with the Ca(2+)-selective ORAI channels at the PM...
August 2016: Cell Calcium
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