The State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Molecular Medicine, Peking University, Beijing, China.
Curr Top Membr. 2013;71:95-108. doi: 10.1016/B978-0-12-407870-3.00004-4.
STIM1 and Orai1 are two essential components of the calcium release-activated calcium (CRAC) channel. Recently, distinct stoichiometries of STIM1 to Orai1 in assembling CRAC channels are proposed based on different techniques, such as single-molecule bleaching, biochemistry, crystallography, and concatenated constructs for electrophysiological experiments. Here, we review in detail these experiments as well as the strength and weakness of methods used. We propose that the tetrameric Orai1 is the pore for the resting and activated CRAC channel, where from two to eight STIM1 proteins open the channel in a graded manner.
STIM1 和 Orai1 是钙释放激活钙 (CRAC) 通道的两个必需组成部分。最近，基于不同的技术，如单分子漂白、生物化学、晶体学和串联构建用于电生理实验，提出了 STIM1 与 Orai1 组装 CRAC 通道的不同计量比。在这里，我们详细回顾了这些实验以及所使用方法的优缺点。我们提出，四聚体 Orai1 是静止和激活的 CRAC 通道的孔，其中 2 到 8 个 STIM1 蛋白以分级方式打开通道。
