Gibhardt Christine Silvia, Cappello Sabrina, Bhardwaj Rajesh, Schober Romana, Kirsch Sonja Agnes, Bonilla Del Rio Zuriñe, Gahbauer Stefan, Bochicchio Anna, Sumanska Magdalena, Ickes Christian, Stejerean-Todoran Ioana, Mitkovski Miso, Alansary Dalia, Zhang Xin, Revazian Aram, Fahrner Marc, Lunz Victoria, Frischauf Irene, Luo Ting, Ezerina Daria, Messens Joris, Belousov Vsevolod Vadimovich, Hoth Markus, Böckmann Rainer Arnold, Hediger Matthias Albrecht, Schindl Rainer, Bogeski Ivan
Molecular Physiology, Institute of Cardiovascular Physiology, University Medical Center, Georg-August-University, Göttingen, Germany.
Department of Nephrology and Hypertension, Inselspital, University of Bern, Bern, Switzerland.
Cell Rep. 2020 Oct 20;33(3):108292. doi: 10.1016/j.celrep.2020.108292.
Store-operated calcium entry (SOCE) through STIM-gated ORAI channels governs vital cellular functions. In this context, SOCE controls cellular redox signaling and is itself regulated by redox modifications. However, the molecular mechanisms underlying this calcium-redox interplay and the functional outcomes are not fully understood. Here, we examine the role of STIM2 in SOCE redox regulation. Redox proteomics identify cysteine 313 as the main redox sensor of STIM2 in vitro and in vivo. Oxidative stress suppresses SOCE and calcium currents in cells overexpressing STIM2 and ORAI1, an effect that is abolished by mutation of cysteine 313. FLIM and FRET microscopy, together with MD simulations, indicate that oxidative modifications of cysteine 313 alter STIM2 activation dynamics and thereby hinder STIM2-mediated gating of ORAI1. In summary, this study establishes STIM2-controlled redox regulation of SOCE as a mechanism that affects several calcium-regulated physiological processes, as well as stress-induced pathologies.
通过基质相互作用分子（STIM）门控的钙释放激活钙通道（ORAI）介导的储存式钙内流（SOCE）调控着重要的细胞功能。在此背景下，SOCE控制细胞氧化还原信号传导，其自身也受氧化还原修饰的调节。然而，这种钙-氧化还原相互作用的分子机制及其功能结果尚未完全明确。在此，我们研究了STIM2在SOCE氧化还原调节中的作用。氧化还原蛋白质组学确定半胱氨酸313是STIM2在体外和体内的主要氧化还原传感器。氧化应激抑制过表达STIM2和ORAI1的细胞中的SOCE和钙电流，半胱氨酸313突变可消除这种效应。荧光寿命成像（FLIM）和荧光共振能量转移（FRET）显微镜以及分子动力学（MD）模拟表明，半胱氨酸313的氧化修饰改变了STIM2的激活动力学，从而阻碍了STIM2介导的ORAI1门控。总之，本研究确立了STIM2控制的SOCE氧化还原调节机制，该机制影响多种钙调节的生理过程以及应激诱导的病理状态。
