Malignant hyperthermia mutation sites in the Leu2442-Pro2477 (DP4) region of RyR1 (ryanodine receptor 1) are clustered in a structurally and functionally definable area
Malignant hyperthermia mutation sites in the Leu2442-Pro2477 (DP4) region of RyR1 (ryanodine receptor 1) are clustered in a structurally and functionally definable area
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DOI：
10.1042/bj20060902
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发表时间：
2007-01-01
影响因子：
4.1
通讯作者：
Ikemoto, Noriaki
中科院分区：
文献类型：
--
作者：
Bannister, Mark L.;Hamada, Tomoyo;Ikemoto, Noriaki
为了解释MH（恶性高热）中通道紊乱的发病机制，我们提出了一个模型，其中RyR1 （ryanodine receptor 1）的n端和中心结构域之间的紧密相互作用稳定了通道的关闭状态，但这些结构域的突变削弱了结构域间的相互作用并使通道不稳定。DP4（结构域肽4）是一种与中心结构域的Leu(2442)-Pro（2477）残基相对应的肽，也会削弱结构域相互作用并产生MH样通道不稳定，而DP4中的MH突变（R2458C）则会消除这些影响。因此，DP4及其突变体是研究其结构功能的良好工具。文献中报道的其他MH突变涉及DP4区域的其他三个氨基酸残基(Arg（24), Iie（2453）和Arg(2454)）。在本文中，我们研究了DP4在这三个残基上的几个突变体的活性。每个Mill突变体激活ryanodine结合或影响Car（2+）释放的能力都严重减弱。其他替代方法效果不太好。结构研究，利用核磁共振分析，揭示了预肽有两个a-螺旋区。很明显，MH突变聚集在第一个螺旋的c末端。本文的数据表明，该区域残基的突变破坏了稳定通道封闭状态的畴间相互作用。
To explain the mechanism of pathogenesis of channel disorder in MH (malignant hyperthermia), we have proposed a model in which tight interactions between the N-terminal and central domains of RyR1 (ryanodine receptor 1) stabilize the closed state of the channel, but mutation in these domains weakens the inter-domain interaction and destabilizes the channel. DP4 (domain peptide 4), a peptide corresponding to residues Leu(2442)-Pro(2477) of the central domain, also weakens the domain interaction and produces MH-like channel destabilization, whereas an MH mutation (R2458C) in DP4 abolishes these effects. Thus DP4 and its mutants serve as excellent tools for structure-function studies. Other MH mutations have been reported in the literature involving three other amino acid residues in the DP4 region (Arg(24), Iie(2453) and Arg(2454)). In the present paper we investigated the activity of several mutants of DP4 at these three residues. The ability to activate ryanodine binding or to effect Car(2+) release was severely diminished for each of the Mill mutants. Other substitutions were less effective. Structural studies, using NMR analysis, revealed that the preptide has two a-helical regions. It is apparent that the MH mutations are clustered at the C-terminal end of the first helix. The data in the present paper indicates that mutation of residues in this region disrupts the interdomain interactions that stabilize the closed state of the channel.