REQUIREMENTS FOR PHOSPHORYLATION OF MAP KINASE DURING MEIOSIS IN XENOPUS OOCYTES
REQUIREMENTS FOR PHOSPHORYLATION OF MAP KINASE DURING MEIOSIS IN XENOPUS OOCYTES
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DOI：
10.1126/science.1313186
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发表时间：
1992-01-10
期刊：
影响因子：
56.9
通讯作者：
COOPER, JA
中科院分区：
文献类型：
--
作者：
POSADA, J;COOPER, JA
有丝分裂原活化蛋白（MAP）激酶通过酪氨酸和苏氨酸残基的磷酸化而响应于多种细胞外刺激而活化。Xp42是非洲爪蟾MAP激酶，在卵母细胞成熟过程中被激活。缺乏酶活性或磷酸化位点的Xp42的修饰形式在非洲爪蟾卵母细胞中表达。当用孕酮诱导减数分裂成熟时，每个突变体Xp42被磷酸化，表明至少有一种激酶被激活，可以使Xp42在酪氨酸和苏氨酸上磷酸化。一个残基的磷酸化并不严格依赖于另一个残基的磷酸化。
Mitogen-activated protein (MAP) kinases are activated in response to a variety of extracellular stimuli by phosphorylation on tyrosine and threonine residues. Xp42 is a Xenopus laevis MAP kinase that is activated during oocyte maturation. Modified forms of Xp42 that lacked enzymatic activity or either of the phosphorylation sites were expressed in Xenopus oocytes. When meiotic maturation was induced with progesterone, each mutant Xp42 was phosphorylated, indicating that at least one kinase was activated that can phosphorylate Xp42 on tyrosine and threonine. Phosphorylation of one residue is not strictly dependent on phosphorylation of the other.