On the synthesis and destruction of A- and B-type cyclins during oogenesis and meiotic maturation in Xenopus laevis
On the synthesis and destruction of A- and B-type cyclins during oogenesis and meiotic maturation in Xenopus laevis
复制标题
非洲爪蟾卵子发生和减数分裂成熟过程中 A 型和 B 型细胞周期蛋白的合成和破坏
作者：
Hideki Kobayashi;Jeremy Minshull;Chris Ford;Roy Golsteyn;Randy Non;Tim Hunt
我们测定了非洲爪蛙在卵子发生、孕酮诱导的卵母细胞成熟和卵子激活后立即周期蛋白mRNAs和多肽的水平。从卵子发生的早期到受精后，每个周期蛋白的信使核糖核酸水平保持在大约5×10(7)个分子的水平上。多肽的水平表现出更复杂的蓄积模式。B型周期蛋白在IV期和V期卵母细胞中首次被检测到。周期蛋白B2多肽在第VI期每个卵母细胞中的含量约为2×10(9)个分子(150pg)。在孕酮处理后，其含量增加，但在GVBD后恢复到以前的水平，直到受精时被破坏，才会发生进一步的变化。周期蛋白B1在VI期卵母细胞中以4×10(8)个分子的形式存在，并在成熟过程中稳步上升，最终达到与未受精卵中周期蛋白B2相似的水平。与B型周期蛋白不同，周期蛋白A在VI期卵母细胞中几乎检测不到，只有在卵母细胞接触黄体酮后才开始大量产生。生发泡破裂(GVBD)后，所有周期蛋白的一部分被破坏，周期蛋白B1和B2在卵母细胞成熟过程中也经历翻译后修饰。孕酮强烈刺激这些卵母细胞周期蛋白和p34cdc2的合成，但周期蛋白的合成在卵子和受精后继续，而p34cdc2的合成在GVBD后强烈下降。从成熟促进因子的激活和失活角度讨论了这些结果的意义。
We have measured the levels of cyclin mRNAs and polypeptides during oogenesis, progesterone-induced oocyte maturation, and immediately after egg activation in the frog, Xenopus laevis. The mRNA for each cyclin is present at a constant level of approximately 5 x 10(7) molecules per oocyte from the earliest stages of oogenesis until after fertilization. The levels of polypeptides show more complex patterns of accumulation. The B-type cyclins are first detectable in stage IV and V oocytes. Cyclin B2 polypeptide is present at approximately 2 x 10(9) molecules (150 pg) per oocyte by stage VI. The amount increases after progesterone treatment, but returns to its previous level after GVBD and undergoes no further change until it is destroyed at fertilization. Cyclin B1 is present at 4 x 10(8) molecules per oocyte in stage VI oocytes, and rises steadily during maturation, ultimately reaching similar levels to cyclin B2 in unfertilized eggs. Unlike the B-type cyclins, cyclin A is barely detectable in stage VI oocytes, and only starts to be made in significant amounts after oocytes are exposed to progesterone. A portion of all the cyclins are destroyed after germinal vesicle breakdown (GVBD), and cyclins B1 and B2 also experience posttranslational modifications during oocyte maturation. Progesterone strongly stimulates both cyclin and p34cdc2 synthesis in these oocytes, but whereas cyclin synthesis continues in eggs and after fertilization, synthesis of p34cdc2 declines strongly after GVBD. The significance of these results is discussed in terms of the activation and inactivation of maturation-promoting factor.
从爪蟾卵中纯化的成熟促进因子的 p34cdc2 蛋白激酶成分的生化特征。
DOI：
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发表时间：
1989
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Erikson,E;Maller,JL
通讯作者：
Maller,JL
非洲爪蟾卵母细胞和细胞分裂的生物化学。
影响因子：
2.9
作者：
Maller,JL
通讯作者：
Maller,JL
影响因子：
11.4
作者：
BRIZUELA, L;DRAETTA, G;BEACH, D
通讯作者：
BEACH, D