Functional dissection of myosin binding protein C phosphorylation
Functional dissection of myosin binding protein C phosphorylation
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DOI：
10.1016/j.yjmcc.2013.08.006
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发表时间：
2013-11-01
影响因子：
5
通讯作者：
Robbins, Jeffrey
中科院分区：
文献类型：
--
作者：
Gupta, Manish K.;Gulick, James;Robbins, Jeffrey
心肌肌球蛋白结合蛋白C(cMyBP-C)的磷酸化在正常心脏和疾病发展过程中受到不同的调节。我们的目标是详细研究该蛋白心脏特异序列中存在的三个可磷酸化位点(Ser-273、Ser-282和Ser-302)，因为这些残基在正常和异常的心功能过程中被差异地和可逆地磷酸化。建立了三个转基因株系：DAA，表达含有Asp-273、Ala-282和Ala-302的cMyBP-C，其中一个带电氨基酸被放置在残基273，其余两个位置通过用丙氨酸取代两个丝氨酸而变得不可磷酸化；MD包含Ala-273、Ala-282和Asp-302，其中天冬氨酸被放置在残基302，其余两个位置变得不可磷酸化；以及含有Ser-273、Asp-282和Ser-302的SDS。这些小鼠与之前沿着类似品系构建的小鼠进行了比较：野生型，其中正常的cMyBP-C被转基因表达，AllP-，其中丙氨酸被取代，以及ADA小鼠。DAA和MD小鼠表现出比cMyBP-C null更严重的病理。DAA和MD动物表现为左室腔扩张、间质纤维化、心律失常和心脏性猝死。我们的结果定义了位点翻译后修饰对cMyBP-C功能的影响，并共同给出了位点特异性磷酸化的潜在后果的综合图景。Ser-282是控制S2与细丝和粗丝相互作用的关键残基。新的DAA和AAD结构表明，根据所涉及的特定残基，在一个位点上的磷酸化而不能磷酸化其他位点，可以导致严重的心脏重构和功能障碍。(C)2013爱思唯尔有限公司。保留所有权利。
Cardiac myosin binding protein C (cMyBP-C) phosphorylation is differentially regulated in the normal heart and during disease development. Our objective was to examine in detail three phosphorylatable sites (Ser-273, Ser-282, and Ser-302) present in the protein's cardiac-specific sequences, as these residues are differentially and reversibly phosphorylated during normal and abnormal cardiac function. Three transgenic lines were generated: DAA, which expressed cMyBP-C containing Asp-273, Ala-282, and Ala-302, in which a charged amino acid was placed at residue 273 and the remaining two sites rendered nonphosphorylatable by substituting alanines for the two serines; MD containing Ala-273, Ala-282, and Asp-302, in which aspartate was placed at residue 302 and the remaining two sites rendered nonphosphorylatable; and SDS containing Ser-273, Asp-282, and Ser-302. These mice were compared to mice constructed previously along similar lines: wild type, in which normal cMyBP-C is transgenically expressed, AllP-, in which alanines were substituted and ADA mice as well. DAA and MD mice showed pathology that was more severe than cMyBP-C nulls. DAA and MD animals exhibited left ventricular chamber dilation, interstitial fibrosis, irregular cardiac rhythm and sudden cardiac death. Our results define the effects of the sites' post-translational modifications on cMyBP-C functionality and together, give a comprehensive picture of the potential consequences of site-specific phosphorylation. Ser-282 is a key residue in controlling S2 interaction with the thick and thin filaments. The new DAA and AAD constructs show that phosphorylation at one site in the absence of the ability to phosphorylate the other sites, depending upon the particular residues involved, can lead to severe cardiac remodeling and dysfunction. (C) 2013 Elsevier Ltd. All rights reserved.