Kinase FA-mediated regulation of rabbit skeletal muscle protein phosphatase. Reversible phosphorylation of the modulator subunit.
Kinase FA-mediated regulation of rabbit skeletal muscle protein phosphatase. Reversible phosphorylation of the modulator subunit.
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激酶 FA 介导的兔骨骼肌蛋白磷酸酶调节。
DOI：
10.1016/s0021-9258(19)39860-6
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
P. Chock
中科院分区：
文献类型：
--
作者：
J. Vandenheede;S. Yang;W. Merlevede;S. Jurgensen;P. Chock
ATP的激活机制。mg依赖性蛋白磷酸酶（FC.M）已被提出（Jurgensen， S., Shacter， E., Huang, c.y., Chock, p.b., Yang， S. d .）。，范登海德，J. R.，梅利韦德，W.（1984）。化学，259,5864-5870)，其中调节亚基(M)的激酶FA的短暂磷酸化是非活性催化亚基（FC）转变为活性构象的驱动力。FC的孵化。M与激酶FA和Mg2+和腺苷5'-（γ -硫）三磷酸结合导致M的硫代磷酸化，并导致磷酸酶催化亚基的构象改变；然而，这种酶仍然不活跃。这种无活性的硫代磷酸化复合物的蛋白水解导致调节亚基的蛋白水解破坏，并产生一种活性的磷酸化酶。对天然失活酶进行类似处理不会产生活性磷酸酶。证据表明，一个分子的调节剂是结合在一个“抑制位点”上的天然酶。在与激酶FA和ATP孵育后，该调节剂不阻止磷酸酶催化亚基的构象变化。而部分抑制磷酸化酶的表达。
A mechanism of activation of the ATP.Mg-dependent protein phosphatase (FC.M) has been proposed (Jurgensen, S., Shacter, E., Huang, C. Y., Chock, P. B., Yang, S.-D., Vandenheede, J. R., and Merlevede, W. (1984) J. Biol. Chem. 259, 5864-5870) in which a transient phosphorylation by the kinase FA of the modulator subunit (M) is the driving force for the transition of the inactive catalytic subunit (FC) into its active conformation. Incubation of FC.M with kinase FA and Mg2+ and adenosine 5'-(gamma-thio)triphosphate results in thiophosphorylation of M and also a conformational change in the phosphatase catalytic subunit; however, the enzyme remains inactive. Proteolysis of this inactive, thiophosphorylated complex causes proteolytic destruction of the modulator subunit and yields an active phosphorylase phosphatase species. Similar treatment of the native inactive enzyme does not yield active phosphatase. Evidence is presented, suggesting that a molecule of modulator is bound at an "inhibitory site" on the native enzyme. This modulator does not prevent the conformational change in the phosphatase catalytic subunit upon incubation with kinase FA and ATP.Mg but does partially inhibit the expression of the phosphorylase phosphatase activity.