The c‐mos proto‐oncogene protein kinase turns on and maintains the activity of MAP kinase, but not MPF, in cell‐free extracts of Xenopus oocytes and eggs.
The c‐mos proto‐oncogene protein kinase turns on and maintains the activity of MAP kinase, but not MPF, in cell‐free extracts of Xenopus oocytes and eggs.
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在爪蟾卵母细胞和卵的无细胞提取物中，c-mos 原癌基因蛋白激酶开启并维持 MAP 激酶的活性，但不维持 MPF 的活性。
DOI：
10.1002/j.1460-2075.1993.tb05847.x
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
T. Hunt
中科院分区：
文献类型：
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作者：
A. R. Nebreda;T. Hunt
在非洲爪蟾卵母细胞和卵的无细胞提取物中细胞周期蛋白B-p34 cdc 2蛋白激酶（MPF）的激活和失活研究期间，我们发现大肠杆菌麦芽糖结合蛋白和非洲爪蟾c-mos蛋白激酶（malE-mos）之间的细菌表达融合蛋白激活了42 kDa MAP激酶。加入malE-mos后MAP激酶的激活是一致的，而MPF的激活是可变的，并且在一些卵母细胞提取物中没有发生，其中细胞周期蛋白A或冈田酸激活MPF和MAP激酶。在MPF激活是短暂的情况下，MPF活性丧失后MAP激酶活性下降，并且MAP激酶（但不是MPF）可以通过男性E-mos的存在维持在高水平。当完整的卵母细胞用孕酮处理，然而，MPF和MAP激酶的激活同时发生，相反的行为提取物。这些观察结果表明，c-mos的一个作用可能是维持减数分裂中高MAP激酶活性。它们还意味着体内MPF和MAP激酶的激活是同步事件，通常依赖于仍有待鉴定的试剂。
During studies of the activation and inactivation of the cyclin B‐p34cdc2 protein kinase (MPF) in cell‐free extracts of Xenopus oocytes and eggs, we found that a bacterially expressed fusion protein between the Escherichia coli maltose‐binding protein and the Xenopus c‐mos protein kinase (malE‐mos) activated a 42 kDa MAP kinase. The activation of MAP kinase on addition of malE‐mos was consistent, whereas the activation of MPF was variable and failed to occur in some oocyte extracts in which cyclin A or okadaic acid activated both MPF and MAP kinase. In cases when MPF activation was transient, MAP kinase activity declined after MPF activity was lost, and MAP kinase, but not MPF, could be maintained at a high level by the presence of malE‐mos. When intact oocytes were treated with progesterone, however, the activation of MPF and MAP kinase occurred simultaneously, in contrast to the behaviour of extracts. These observations suggest that one role of c‐mos may be to maintain high MAP kinase activity in meiosis. They also imply that the activation of MPF and MAP kinase in vivo are synchronous events that normally rely on an agent that has still to be identified.