Myosin and contractile activity in smooth muscle.
Myosin and contractile activity in smooth muscle.
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肌球蛋白和平滑肌的收缩活动。
DOI：
10.1007/978-1-4684-5679-0_30
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发表时间：
1989
影响因子：
--
通讯作者：
Ikebe,M
中科院分区：
文献类型：
--
作者：
Hartshorne,DJ;Ito,M;Ikebe,M
在松弛的肌肉中，收缩装置处于休眠状态，收缩的开始需要激活。人们普遍认为这种激活是通过肌球蛋白(LC20)的两个20,000道尔顿轻链的磷酸化实现的，通常丝氨酸19是磷酸化的。这一过程是由肌球蛋白轻链激酶(MLCK)催化的，该系统的钙依赖性是由于钙离子4钙调素(CaM)复合体激活了MLCK酶。收缩装置的去磷酸化和失活，反映了一种轻链磷酸酶的活性。然而，后者还没有得到很好的表征，例如，是否涉及一种或多种磷酸酶，或者磷酸酶活性是否受到调节，目前还不清楚。
In relaxed smooth muscle the contractile apparatus is dormant and the initiation of contraction requires an activation. It is generally agreed that the activation is achieved by phosphorylation of the two 20,000-dalton light chains of myosin (LC20) and usually Serine 19 is phosphorylated. This process is catalyzed by myosin light chain kinase (MLCK) and the Ca2+-dependence of the system is due to the activation of the MLCK apoenzyme by the Ca2+4 calmodulin (CaM) complex. Dephosphorylation and inactivation of the contractile apparatus, reflects the activity of a light chain phosphatase. The latter, however, has not been well characterized and it is not known, for example, if one or more phosphatases are involved or, if the phosphatase activity is regulated.