Regulation of intrasteric inhibition of the multifunctional calcium/calmodulin-dependent protein kinase.
Regulation of intrasteric inhibition of the multifunctional calcium/calmodulin-dependent protein kinase.
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多功能钙/钙调蛋白依赖性蛋白激酶的空间内抑制的调节。
DOI：
10.1073/pnas.89.24.12127
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发表时间：
1992
影响因子：
11.1
通讯作者：
Means,AR
中科院分区：
文献类型：
--
作者：
Cruzalegui,FH;Kapiloff,MS;Morfin,JP;Kemp,BE;Rosenfeld,MG;Means,AR
此前已在多功能Ca 2 +/CaM依赖性蛋白激酶（CaM激酶II）中发现了参与自抑制和钙调蛋白（CaM）结合的调节区域。我们已经测试了一系列的截断，取代和缺失突变体的钙调蛋白激酶II α亚基（钙调蛋白激酶II α）的分析，在自抑制的调节区的各个部分的作用。出乎意料的是，发现与CaM结合结构域相邻的位置291-294处的序列Lys-Lys-Phe-Asn足以维持激酶的截短形式的抑制状态。然而，这些残基在全长蛋白的背景下不是必需的，表明来自重叠的CaM结合结构域的额外残基的重要性。我们提出了一个基于cAPK-PKI-（5-24）（蛋白激酶抑制剂片段）复合物三维结构的CaM激酶II α分子模型。从这个模型中可以预测，自抑制是假底物的品种和自磷酸化的Thr-286可能发生的intersubunit反应中的全酶复合物。
A regulatory region involved in both autoinhibition and calmodulin (CaM) binding has previously been identified in the multifunctional Ca2+/CaM-dependent protein kinase (CaM kinase II). We have tested the role of various segments of the regulatory region in autoinhibition by the analysis of a series of truncation, substitution, and deletion mutants of the CaM kinase II alpha subunit (CaM kinase II alpha). Unexpectedly, the sequence Lys-Lys-Phe-Asn at positions 291-294, adjacent to the CaM binding domain, was found to be sufficient to maintain an inhibited state in a truncated form of the kinase. However, these residues are not essential in the context of the full-length protein, indicating the importance of additional residues from the overlapping CaM binding domain. We propose here a molecular model for CaM kinase II alpha based on the three-dimensional structure of the cAPK-PKI-(5-24) (protein kinase inhibitor fragment) complex. It is predicted from this model that autoinhibition is of the pseudosubstrate variety and that autophosphorylation of Thr-286 could occur by an intersubunit reaction in the holoenzyme complex.