Phosphorylation of calmodulin by myosin light chain kinase is altered by exchange or duplication of EF-hand pairs.
Phosphorylation of calmodulin by myosin light chain kinase is altered by exchange or duplication of EF-hand pairs.
复制标题
肌球蛋白轻链激酶对钙调蛋白的磷酸化通过 EF-手对的交换或复制而改变。
DOI：
10.1006/bbrc.1997.7029
复制
发表时间：
1997
影响因子：
3.1
通讯作者：
Davis,HW
中科院分区：
文献类型：
--
作者：
Davis,HW
我们以前已经证明，在某些条件下，肌球蛋白轻链激酶可以磷酸化其激活剂，钙调蛋白。在这项研究中，我们表明，肌球蛋白轻链激酶从鸡砂囊可以磷酸化重组钙调素，其中EF-手对（钙离子结合结构域）的复制或交换。使用三种突变体CaMNN（氨基末端EF-手对被复制）、CaMCC（羧基末端EF-手对被复制）和CaMCN（羧基和氨基末端EF-手对被转换）。肌球蛋白轻链激酶磷酸化CaMNN和CaMCN在更大程度上比野生型钙调素，但没有磷酸化CaMCC。虽然CaMCC是肌球蛋白轻链激酶催化的肌球蛋白轻链磷酸化的竞争性抑制剂，但在这些研究中使用的条件下，它不能阻止天然钙调蛋白的磷酸化。这些数据表明，虽然羧基和氨基末端EF-手对是相似的，它们的方向可以区分由鸡砂囊肌球蛋白轻链激酶。
We have previously demonstrated that under certain conditions, myosin light chain kinase can phosphorylate its activator, calmodulin. In this study we show that myosin light chain kinase from chicken gizzard can phosphorylate recombinant calmodulins in which the EF-hand pairs (Ca2+-binding domains) are duplicated or exchanged. Three mutants were used CaMNN (the amino-terminal EF-hand pair is duplicated), CaMCC (the carboxy-terminal EF-hand pair is duplicated) and CaMCN (the carboxy- and amino-terminal EF-hand pairs are switched). Myosin light chain kinase phosphorylated CaMNN and CaMCN to a greater extent than wild-type CaM but did not phosphorylate CaMCC. While CaMCC is a competitive inhibitor of myosin light chain kinase-catalyzed phosphorylation of myosin light chains, it did not prevent the phosphorylation of native calmodulin under the conditions employed in these studies. These data suggest that, although the carboxy- and amino-terminal EF-hand pairs are similar, their orientation can be distinguished by chicken gizzard myosin light chain kinase.