Increased phosphorylation of ribosomal protein S6 during meiotic maturation of Xenopus oocytes.
Increased phosphorylation of ribosomal protein S6 during meiotic maturation of Xenopus oocytes.
复制标题
非洲爪蟾卵母细胞减数分裂成熟过程中核糖体蛋白 S6 的磷酸化增加。
DOI：
10.1073/pnas.79.9.2937
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发表时间：
1982
影响因子：
11.1
通讯作者：
Maller,JL
中科院分区：
文献类型：
--
作者：
Nielsen,PJ;Thomas,G;Maller,JL
一个单一的核糖体蛋白质（先生，32,000）成为磷酸化在甾体酮诱导的非洲爪蟾卵母细胞体外成熟。该蛋白被鉴定为40 S核糖体蛋白S6。通过掺入32 Pi和通过二维聚丙烯酰胺凝胶电泳监测S6的磷酸化。S6在未刺激的卵母细胞中磷酸化程度最低。孕酮处理后，S6的磷酸化先于生殖囊泡破裂（GVBD），并在50%的卵母细胞经历GVBD时达到最大。S6，当最大程度磷酸化时，存在于衍生物中，对应于在其他系统中观察到的最高度磷酸化的形式，并且S6磷酸化的增加与卵母细胞成熟期间报告的总体蛋白质合成速率的增加大致同时发生。在体内成熟后，S6在未受精卵中也被最大程度地磷酸化。将部分纯化的促成熟因子注射到未成熟卵母细胞中，可诱导S6立即磷酸化，并迅速增加蛋白质合成速率。此外，核糖体与该因子和放射性标记的ATP孵育导致S6的标记。这些结果表明，S6磷酸化可能是重要的成熟过程中的蛋白质合成的控制，也可能发挥作用的成熟促进因子的作用机制。
A single ribosomal protein (Mr, 32,000) becomes phosphorylated during progesterone-induced in vitro maturation of Xenopus laevis oocytes. The protein is identified as 40S ribosomal protein S6. Phosphorylation of S6 is monitored by incorporation of 32Pi and by two-dimensional polyacrylamide gel electrophoresis. S6 is minimally phosphorylated in unstimulated oocytes. After progesterone treatment, phosphorylation of S6 precedes germinal vesicle breakdown (GVBD) and is maximal at the time when 50% of the oocytes have undergone GVBD. S6, when maximally phosphorylated, exists in derivatives that correspond to the most highly phosphorylated forms observed in other systems, and the increase in S6 phosphorylation occurs at approximately the same time as the increase in the overall protein synthesis rate reported to occur during oocyte maturation. S6 is also maximally phosphorylated in unfertilized eggs following maturation in vivo. Injection of a partially purified preparation of maturation-promoting factor into immature oocytes induces immediate phosphorylation of S6 and rapidly increases the rate of protein synthesis. Moreover, incubation of ribosomes with this factor and radiolabeled ATP results in labeling of S6. These findings suggest that S6 phosphorylation may be important in the control of protein synthesis during maturation and may also play a role in the mechanism of action of maturation-promoting factor.