A novel p34cdc2-binding and activating protein that is necessary and sufficient to trigger G2/M progression in Xenopus oocytes
A novel p34cdc2-binding and activating protein that is necessary and sufficient to trigger G2/M progression in Xenopus oocytes
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DOI：
10.1101/gad.13.16.2177
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发表时间：
1999-08-15
影响因子：
10.5
通讯作者：
Nebreda, AR
中科院分区：
文献类型：
--
作者：
Ferby, I;Blazquez, M;Nebreda, AR
成熟促进因子（MPF）的激活是真核细胞G（2）/M进程所必需的。爪蟾卵母细胞在孕酮刺激下被阻滞在G（2）期，猿卵母细胞被诱导进入减数分裂的M期。这个过程被称为减数分裂成熟，需要翻译储存在卵母细胞中的特定母体mRNA。我们已经使用了表达克隆的策略，功能性地确定蛋白质参与非洲爪蟾卵母细胞的G（2）/M进程。在这里，我们报告了两个新的cDNA的克隆，当在卵母细胞中表达诱导减数分裂成熟有效。这两个cDNA编码33 kD的蛋白质，88%相同，没有显着的同源性，与数据库中的其他序列。这些蛋白质，我们称之为p33（ringo）（卵母细胞中G（2）/M进程的快速诱导剂），在环己酰亚胺处理的卵母细胞中诱导非常快速的MPF激活。相反，使用反义寡核苷酸消融内源性p33（ringo）mRNA抑制了孕酮诱导的成熟，表明p33（ringo）的合成是这一过程所必需的。我们还表明，p33（环）结合并激活p34（cdc 2）的激酶活性，但不与p34（cdc 2）/细胞周期蛋白B复合物。我们的研究结果确定了一种新的p34（cdc 2）结合和激活蛋白，调节卵母细胞成熟过程中的G（2）/M转换。
The activation of maturation-promoting factor (MPF) is required for G(2)/M progression in eukaryotic cells. Xenopus oocytes are arrested in G(2) and ape induced to enter M phase of meiosis by progesterone stimulation. This process is known as meiotic maturation and requires the translation of specific maternal mRNAs stored in the oocytes. We have used an expression cloning strategy to functionally identify proteins involved in G(2)/M progression in Xenopus oocytes. Here we report the cloning of two novel cDNAs that when expressed in oocytes induce meiotic maturation efficiently. The two cDNAs encode proteins of 33 kD that are 88% identical and have no significant homologies to other sequences in databases. These proteins, which we refer to as p33(ringo) (rapid inducer of G(2)/M progression in oocytes), induce very rapid MPF activation in cycloheximide-treated oocytes. Conversely, ablation of endogenous p33(ringo) mRNAs using antisense oligonucleotides inhibits progesterone-induced maturation, suggesting that synthesis of p33(ringo) is required for this process. We also show that p33(ringo) binds to and activates the kinase activity of p34(cdc2) but does not associate with p34(cdc2)/cyclin B complexes. Our results identify a novel p34(cdc2) binding and activating protein that regulates the G(2)/M transition during oocyte maturation.