Interaction of the Homer1 EVH1 domain and skeletal muscle ryanodine receptor
Interaction of the Homer1 EVH1 domain and skeletal muscle ryanodine receptor
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Homer1 EVH1 结构域和骨骼肌兰尼碱受体的相互作用
DOI：
10.1016/j.bbrc.2019.04.199
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发表时间：
2019
影响因子：
3.1
通讯作者：
Yin Changcheng
中科院分区：
文献类型：
--
作者：
Wang Tingting;Zhang Lei;Shi Chao;Wei Risheng;Yin Changcheng
骨骼肌Ryanodine受体（RyR 1）蛋白是肌浆网（SR）膜上的细胞内钙（Ca 2+）释放通道，并且是骨骼肌兴奋-收缩偶联所必需的。Homer（Vesl）是一个支架蛋白家族，其通过保守的EVH 1（Ena/VASP同源1）结构域调节靶蛋白，包括RyR（ryanodine受体）、mGluR（1组代谢型谷氨酸受体）和IP 3R（肌醇-1，4，5-三磷酸受体）。在这里，我们研究了Homer 1 EVH 1结构域和RyR 1之间的相互作用，通过免疫共沉淀，连续蔗糖密度梯度离心，和生物层干涉结合试验在不同的Ca 2+浓度。我们的研究结果表明，有一个高亲和力的Homer 1 EVH 1结构域和RyR 1之间的结合，特别是在1 mM的Ca 2+。基于我们的数据和已知的Homer 1 EVH 1结构域和RyR 1的结构，我们发现在RyR 1的结构中有两个共有的富含脯氨酸的序列，PPHHF和FLPPP，并提出了两个相应的结合模型，以显示不同于其他富含脯氨酸的基序所使用的识别机制。来自RyR 1的两个富含脯氨酸的基序的侧脯氨酸残基远离Homer 1 EVH 1的疏水表面，而不是埋在该疏水表面中。我们的研究结果提供了证据，Homer 1调节RyR 1的直接相互作用。
The skeletal muscle ryanodine receptor (RyR1) proteins are intracellular calcium (Ca2+) release channels on the membrane of the sarcoplasmic reticulum (SR) and required for skeletal muscle excitation-contraction coupling. Homer (Vesl) is a family of scaffolding proteins that modulate target proteins including RyRs (ryanodine receptors), mGluRs (group 1 metabotropic glutamate receptors) and IP3Rs (inositol-1,4,5-trisphosphate receptors) through a conserved EVH1 (Ena/VASP homology 1) domain. Here, we examined the interaction between Homer1 EVH1 domain and RyR1 by co-immunoprecipitation, continuous sucrose density-gradient centrifugation, and bio-layer interferometry binding assay at different Ca2+concentrations. Our results show that there exists a high-affinity binding between the Homer1 EVH1 domain and RyR1, especially at 1 mM of Ca2+. Based on our data and the known structures of Homer1 EVH1 domain and RyR1, we found two consensus proline-rich sequences in the structure of RyR1, PPHHF and FLPPP, and proposed two corresponding binding models to show mechanisms of recognition different from those used by other proline-rich motifs. The side proline residues of two proline-rich motifs from RyR1 are away from the hydrophobic surface of Homer1 EVH1, rather than buried in this hydrophobic surface. Our results provide evidence that Homer1 regulates RyR1 by direct interaction.