Interactions, functions, and independence of plasma membrane STIM1 and TRPC1 in vascular smooth muscle cells.
Interactions, functions, and independence of plasma membrane STIM1 and TRPC1 in vascular smooth muscle cells.
复制标题
血管平滑肌细胞质膜 STIM1 和 TRPC1 的相互作用、功能和独立性。
DOI：
10.1161/circresaha.108.182931
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发表时间：
2008-10-10
影响因子：
20.1
通讯作者：
Beech, David J.
中科院分区：
文献类型：
--
作者：
Li, Jing;Sukumar, Piruthivi;Milligan, Carol J.;Kumar, Bhaskar;Ma, Zhi-Yong;Munsch, Christopher M.;Jiang, Lin-Hua;Porter, Karen E.;Beech, David J.
关键词：
基质相互作用分子1（STIM 1）是一种预测的单跨膜蛋白，参与钙库操作的钙进入并与包括TRPC 1在内的离子通道相互作用。在这里，我们专注于调制血管平滑肌细胞，表现出非选择性的阳离子电流响应存储耗尽，尽管在生理浓度的细胞内钙的强缓冲内源性STIM 1。STIM 1 mRNA和蛋白的检测和抑制特异性短干扰RNA（siRNA）。STIM 1 siRNA部分抑制了钙库耗竭引起的钙内流，而钙释放不受影响。STIM 1 siRNA抑制细胞迁移，但不抑制增殖。特异性结合STIM 1的抗体揭示了STIM 1的组成性细胞外N末端，并且该抗体的细胞外应用引起了对由存储耗尽引起的电流的快速抑制。该抗体还抑制钙进入和细胞迁移，但不增殖。STIM 1与TRPC 1相互作用，TRPC 1部分参与钙离子内流和阳离子电流。然而，根本的过程不能解释只有一个STIM 1-TRPC 1的伙伴关系，因为细胞外TRPC 1抗体抑制阳离子电流只在一小部分的细胞，TRPC 1的通道是重要的细胞增殖以及迁移，和细胞表面定位研究显示TRPC 1单独以及与STIM 1。这些数据表明了一种复杂的情况，其中存在跨质膜的STIM 1，这对细胞迁移和TRPC 1独立的存储操作的阳离子电流很重要，但也存在TRPC 1-STIM 1相互作用，TRPC 1依赖的存储操作电流的组成部分，以及与细胞增殖相关的STIM 1独立的TRPC 1。
Stromal interaction molecule 1 (STIM1) is a predicted single membrane-spanning protein involved in store-operated calcium-entry and interacting with ion channels including TRPC1. Here we focus on endogenous STIM1 of modulated vascular smooth muscle cells, which exhibited a non-selective cationic current in response to store-depletion despite strong buffering of intracellular calcium at the physiological concentration. STIM1 mRNA and protein were detected and suppressed by specific short interfering RNA (siRNA). Calcium entry evoked by store-depletion was partially inhibited by STIM1 siRNA, where as calcium-release was unaffected. STIM1 siRNA suppressed cell migration but not proliferation. Antibody that specifically bound STIM1 revealed constitutive extracellular N-terminus of STIM1 and extracellular application of the antibody caused fast inhibition of the current evoked by store-depletion. The antibody also inhibited calcium entry and cell migration but not proliferation. STIM1 interacted with TRPC1 and TRPC1 contributed partially to calcium entry and cationic current. However, the underlying processes could not be explained only by a STIM1-TRPC1 partnership because extracellular TRPC1 antibody suppressed cationic current only in a fraction of cells, TRPC1-containing channels were important for cell proliferation as well as migration, and cell surface localisation studies revealed TRPC1 alone as well as with STIM1. The data suggest a complex situation where there is plasma membrane-spanning STIM1 that is important for cell migration and TRPC1-independent store-operated cationic current, but also TRPC1-STIM1 interaction, a TRPC1-dependent component of store-operated current, and STIM1-independent TRPC1 linked to cell proliferation.