A Ca2+-binding domain in RyR1 that interacts with the calmodulin binding site and modulates channel activity.
A Ca2+-binding domain in RyR1 that interacts with the calmodulin binding site and modulates channel activity.
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DOI：
10.1529/biophysj.105.066092
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发表时间：
2006
影响因子：
3.4
通讯作者：
L. Xiong;Jia-Zheng Zhang;Rong L. He;S. Hamilton
中科院分区：
文献类型：
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作者：
L. Xiong;Jia-Zheng Zhang;Rong L. He;S. Hamilton
RyR 1的一个片段（氨基酸4064-4210）被预测折叠成钙调蛋白的至少一个叶并结合Ca（2+）。将此RyR 1片段（R4064-4210）亚克隆、表达、重折叠并纯化。与预测的折叠模式一致，发现R4064-4210结合两个Ca（2+）分子，并在结合Ca（2+）后发生结构变化，暴露疏水氨基酸。R4064-4210还与RyR 1、L型Ca（2+）通道（Cav（1.1））和几种合成钙调蛋白结合肽结合。R4064-4210和代表RyR 1的钙调蛋白结合区的肽（R3614-3643）改变（3）H）ryanodine与RyR 1结合的Ca（2+）依赖性，这表明它们都可能干扰氨基酸4064-4210和氨基酸3614- 4215之间的分子内相互作用。3643在天然RyR 1中改变或调节通道对Ca（2+）浓度变化的反应。RyR 1内的一个结构域结合Ca（2+）并与钙调素结合基序相互作用的发现可能为该通道的钙和钙调素依赖性调节机制以及L型Ca（2+）通道对其的调节提供见解。
A fragment of RyR1 (amino acids 4064-4210) is predicted to fold to at least one lobe of calmodulin and to bind Ca(2+). This fragment of RyR1 (R4064-4210) was subcloned, expressed, refolded, and purified. Consistent with the predicted folding pattern, R4064-4210 was found to bind two molecules of Ca(2+) and undergo a structural change upon binding Ca(2+) that exposes hydrophobic amino acids. R4064-4210 also binds to RyR1, the L-type Ca(2+) channel (Cav(1.1)), and several synthetic calmodulin binding peptides. Both R4064-4210 and a peptide representing the calmodulin-binding region of RyR1 (R3614-3643) alter the Ca(2+) dependence of ((3)H)ryanodine binding to RyR1, suggesting that they may both be interfering with an intramolecular interaction between amino acids 4064-4210 and amino acids 3614-3643 in the native RyR1 to alter or regulate the response of the channel to changes in Ca(2+) concentration. The finding that a domain within RyR1 binds Ca(2+) and interacts with calmodulin-binding motifs may provide insights into the mechanism for calcium- and calmodulin-dependent regulation of this channel and perhaps for its regulation by the L-type Ca(2+) channel.