Myosin phosphatase: subunits and interactions.
Myosin phosphatase: subunits and interactions.
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DOI：
10.1046/j.1365-201x.1998.00447.x
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发表时间：
1998-12
期刊：
影响因子：
--
通讯作者：
D. Hartshorne
中科院分区：
文献类型：
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作者：
D. Hartshorne
肌球蛋白磷酸化是调节平滑肌收缩活动的重要机制。肌球蛋白磷酸化水平取决于肌球蛋白轻链激酶和肌球蛋白磷酸酶两种酶的平衡。最近发现肌球蛋白磷酸酶可以被调节，这重新引起了人们对磷酸酶特性的兴趣。肌球蛋白磷酸酶由三个亚基组成：1型磷酸酶的催化亚基（δ亚型; PP 1c δ）;和两个非催化亚基，大和小（M20）。大亚基被认为是靶向亚基，并被称为肌球蛋白磷酸酶靶亚基（MYPT）。MYPT有几种亚型，在人类1号和12号染色体上鉴定出两种基因。MYPT的一个主要特征是在分子的N-末端有一系列锚蛋白重复序列，这些重复序列可能参与与催化亚基和底物磷酸化肌球蛋白的结合。此外，在锚蛋白基序的N-末端边缘是一个共识PP 1c结合基序。M20亚基的功能尚未确定，但已知与MYPT的C末端结合。讨论了可能与磷酸酶活性调节相关的亚基之间的各种相互作用。
Myosin phosphorylation is an important mechanism in regulating contractile activity of smooth muscle. The level of myosin phosphorylation depends on the balance of two enzymes, myosin light chain kinase and myosin phosphatase. Recently it has been discovered that myosin phosphatase can be regulated and this renewed interest in characterization of the phosphatase. It is suggested that the myosin phosphatase is composed of three subunits: a catalytic subunit of type 1 phosphatase (delta isoform; PP1c delta); and two non-catalytic subunits, large and small (M20). The large subunit is thought to be a targeting subunit and is termed myosin phosphatase target subunit (MYPT). There are several isoforms of MYPT and two genes have been identified on human chromosomes 1 and 12. A dominant feature of MYPT is a series of ankyrin repeats at the N-terminal end of the molecule and these may be involved in binding to the catalytic subunit and to substrate, phosphorylated myosin. In addition, at the N-terminal fringe of the ankyrin motifs is a consensus PP1c binding motif. The function of the M20 subunit is not established but is known to bind to the C-terminal end of MYPT. Various interactions between subunits that might be relevant for the regulation of phosphatase activity are discussed.