Department of Physiology, Cell Physiology Research Group, University of Extremadura, Cáceres 10003, Spain.
Adv Exp Med Biol. 2012;740:349-82. doi: 10.1007/978-94-007-2888-2_15.
Store-operated Ca(2+) entry (SOCE) is an ubiquitous and major mechanism for Ca(2+) influx in mammalian cells with important physiological relevance. Since the discovery of SOCE in 1986 both, the mechanism that communicates the amount of Ca(2+) accumulated in the intracellular Ca(2+) stores to the plasma membrane channels and the nature of the capacitative channels, have been a matter of intense investigation. During the last decade, two of the major elements of SOCE, STIM1, the Ca(2+) sensor of the intracellular Ca(2+) compartments, and Orai1, the protein forming the channel that conducts the capacitative Ca(2+) release-activated current I (CRAC), were identified. Together with these proteins, different homologues, including STIM2, Orai2 and Orai3, were identified, although their relevance in SOCE has not been fully characterized yet. Before the identification of STIM1 and Orai1, TRPC proteins were found to be involved in SOCE in different cell types, more likely conducting the non-selective capacitative current described as I (SOC). Current evidence indicates that STIM1, Orai1 and TRPC proteins dynamically interact forming a ternary complex that mediates SOCE in a number of cellular models. The dynamic interaction of STIM1 with Orai1, TRPCs or both might provide an explanation to the distinct capacitative currents described in different cell types.
钙库操纵性钙内流（SOCE）是哺乳动物细胞中钙内流的一种普遍且主要的机制，具有重要的生理相关性。自 1986 年发现 SOCE 以来，沟通细胞内钙库中积累的钙量与质膜通道的机制以及电容性通道的性质一直是深入研究的主题。在过去的十年中，SOCE 的两个主要组成部分，即内质网 Ca2+传感器 1（STIM1）和形成电容性 Ca2+释放激活电流 I（CRAC）通道的蛋白 Orai1，被鉴定出来。除了这些蛋白，还鉴定了不同的同源物，包括 STIM2、Orai2 和 Orai3，尽管它们在 SOCE 中的相关性尚未完全阐明。在鉴定 STIM1 和 Orai1 之前，已经发现 TRPC 蛋白参与了不同细胞类型的 SOCE，更可能是通过描述为 I（SOC）的非选择性电容性电流。目前的证据表明，STIM1、Orai1 和 TRPC 蛋白动态相互作用形成一个三元复合物，在许多细胞模型中介导 SOCE。STIM1 与 Orai1、TRPC 或两者的动态相互作用可能为不同细胞类型中描述的不同电容性电流提供了一种解释。
