Structural signature of the MYPT1-PP1 interaction.
Structural signature of the MYPT1-PP1 interaction.
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MYPT1-PP1 相互作用的结构特征。
DOI：
10.1021/ja107810r
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发表时间：
2011
影响因子：
15
通讯作者：
Peti,Wolfgang
中科院分区：
文献类型：
--
作者：
Pinheiro,AndersonS;Marsh,JosephA;Forman-Kay,JulieD;Peti,Wolfgang
肌球蛋白调节轻链中Ser 19的去磷酸化触发肌肉松弛。该反应由全酶肌球蛋白磷酸酶（MP）催化，其包括催化亚基蛋白磷酸酶1（PP 1）和调节靶向亚基（MYPT）。MYPT 1（肌球蛋白磷酸酶靶向亚基1）负责将全酶靶向肌肉中的亚细胞区室，并将PP 1特异性导向肌球蛋白。为了理解导致MYPT 1 − PP 1全酶形成的分子事件，我们使用NMR光谱来确定未结合MYPT 1的结构和动力学特征。这使得MYPT 1在游离、未结合状态下的构象可以直接与PP 1结合状态进行比较。我们的研究结果表明，MYPT 11 − 98在溶液中表现得像一个双结构域蛋白。MYPT 11 −98的前40个残基，即无序区，本质上是无序的，高度动态的，而残基41−98，即折叠的锚定重复区，结构良好，刚性强。此外，NMR和生物物理数据的综合使用使我们能够计算MYPT 11 −98的系综模型。MYPT 11 − 98系综最显著的结构特征是MYPT 11 −98无序区域中25%的瞬时α-螺旋。当与PP 1结合时，这个α-螺旋变得完全填充，正如我们所展示的，可能在MYPT 1 − PP 1全酶复合物的形成中起着核心作用。最后，这种组合的分析表明，PP 1的MYPT 1表现出的结构和动力学行为是不同于任何其他先前分析的PP 1调节蛋白。总的来说，这些数据使我们能够提出一个新的模型的分子事件，驱动MYPT 1-PP 1全酶的形成，并证明有未结合的PP 1调节剂，以前没有观察到的结构差异。因此，这项工作增加了显着的见解，目前有限的数据的分子结构和动力学的PP 1监管机构。
Muscle relaxation is triggered by the dephosphorylation of Ser19 in the myosin regulatory light chain. This reaction is catalyzed by the holoenzyme myosin phosphatase (MP), which includes the catalytic subunit protein phosphatase 1 (PP1) and the regulatory targeting subunit (MYPT). MYPT1 (myosin phosphatase targeting subunit 1) is responsible for both targeting the holoenzyme to subcellular compartments in the muscle and directing PP1 specificity toward myosin. To understand the molecular events leading to the MYPT1−PP1 holoenzyme formation, we used NMR spectroscopy to determine the structural and dynamic characteristics of unbound MYPT1. This allowed the conformations of MYPT1 in the free, unbound state to be directly compared to the PP1-bound state. Our results show that MYPT11−98behaves like a two-domain protein in solution. The first 40 residues of MYPT11−98, the disordered region, are intrinsically disordered and highly dynamic, whereas residues 41−98, the folded ankyrin-repeat region, are well-structured and rigid. Furthermore, the integrated use of NMR and biophysical data enabled us to calculate an ensemble model for MYPT11−98. The most prominent structural feature of the MYPT11−98ensemble is a 25% populated transient α-helix in the disordered region of MYPT11−98. This α-helix becomes fully populated when bound to PP1 and, as we show, likely plays a central role in the formation of the MYPT1−PP1 holoenzyme complex. Finally, this combined analysis shows that the structural and dynamic behaviors exhibited by MYPT1 for PP1 are distinct from those of any other previously analyzed PP1 regulatory protein. Collectively, these data enable us to present a new model of the molecular events that drive MYPT1−PP1 holoenzyme formation and demonstrate that there are structural differences in unbound PP1 regulators that have not been previously observed. Thus, this work adds significant insights to the currently limited data for molecular structures and dynamics of PP1 regulators.