Conformational Changes in the Orai1 C-Terminus Evoked by STIM1 Binding.
Conformational Changes in the Orai1 C-Terminus Evoked by STIM1 Binding.
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DOI：
10.1371/journal.pone.0128622
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Prakriya M
中科院分区：
文献类型：
--
作者：
Tirado-Lee L;Yamashita M;Prakriya M
储存操纵的CRAC通道调节广泛的细胞功能，包括基因表达、趋化性和增殖。CRAC通道由两种组分组成：形成离子选择性孔的奥赖蛋白（Orai 1 -3）和形成内质网（ER）Ca 2+传感器的STIM蛋白（STIM 1 -2）。CRAC通道的激活是由STIM 1迁移到ER-质膜（PM）连接处引发的，在那里它直接与Orai 1相互作用，打开CRAC通道的Ca 2+选择性孔。最近对果蝇奥赖结构的阐明揭示了一个六聚体通道，其中相邻奥赖亚基的C-末端螺旋以反平行方向缔合。这种关联是通过果蝇相当于人类Orai 1残基L273和L276之间的疏水相互作用来维持的。在这里，我们使用诱变和化学交联来评估STIM 1结合过程中自相关Orai 1 C-末端构象变化的性质和程度。我们发现，通过二硫键交联连接相邻Orai 1 C-末端的反平行卷曲螺旋减少了STIM 1-Orai 1相互作用，如FRET所评估。相反，STIM 1与Orai 1 C-末端的先前结合损害Orai 1 C-末端的交联。突变分析表明，Orai 1螺旋的弯曲位于自相关卷曲（由氨基酸序列SHK形成）的上游，建立了STIM 1结合所需的Orai 1 C-末端的适当方向。总之，我们的研究结果支持一个模型，其中自相关Orai 1 C-末端适度重排，以适应STIM 1结合。
Store-operated CRAC channels regulate a wide range of cellular functions including gene expression, chemotaxis, and proliferation. CRAC channels consist of two components: the Orai proteins (Orai1-3), which form the ion-selective pore, and STIM proteins (STIM1-2), which form the endoplasmic reticulum (ER) Ca2+ sensors. Activation of CRAC channels is initiated by the migration of STIM1 to the ER-plasma membrane (PM) junctions, where it directly interacts with Orai1 to open the Ca2+-selective pores of the CRAC channels. The recent elucidation of the Drosophila Orai structure revealed a hexameric channel wherein the C-terminal helices of adjacent Orai subunits associate in an anti-parallel orientation. This association is maintained by hydrophobic interactions between the Drosophila equivalents of human Orai1 residues L273 and L276. Here, we used mutagenesis and chemical cross-linking to assess the nature and extent of conformational changes in the self-associated Orai1 C-termini during STIM1 binding. We find that linking the anti-parallel coiled-coils of the adjacent Orai1 C-termini through disulfide cross-links diminishes STIM1-Orai1 interaction, as assessed by FRET. Conversely, prior binding of STIM1 to the Orai1 C-terminus impairs cross-linking of the Orai1 C-termini. Mutational analysis indicated that a bend of the Orai1 helix located upstream of the self-associated coils (formed by the amino acid sequence SHK) establishes an appropriate orientation of the Orai1 C-termini that is required for STIM1 binding. Together, our results support a model wherein the self-associated Orai1 C-termini rearrange modestly to accommodate STIM1 binding.
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影响因子：
64.5
作者：
Park CY;Hoover PJ;Mullins FM;Bachhawat P;Covington ED;Raunser S;Walz T;Garcia KC;Dolmetsch RE;Lewis RS
通讯作者：
Lewis RS
DOI：
10.1126/science.1228757
发表时间：
2012-12-07
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Hou X;Pedi L;Diver MM;Long SB
通讯作者：
Long SB
DOI：
10.1073/pnas.1101664108
发表时间：
2011-08-09
影响因子：
11.1
作者：
Hoover, Paul J.;Lewis, Richard S.
通讯作者：
Lewis, Richard S.
通过不同数量的 STIM1 与 Orai1 亚基的结合分级激活 CRAC 通道
影响因子：
44.1
作者：
Li, Zhengzheng;Liu, Lin;Xu, Tao
通讯作者：
Xu, Tao
影响因子：
5.5
作者：
McNally, Beth A.;Somasundaram, Agila;Prakriya, Murali
通讯作者：
Prakriya, Murali