HUMAN HOMOLOG OF FISSION YEAST CDC25 MITOTIC INDUCER IS PREDOMINANTLY EXPRESSED IN G2
HUMAN HOMOLOG OF FISSION YEAST CDC25 MITOTIC INDUCER IS PREDOMINANTLY EXPRESSED IN G2
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DOI：
10.1073/pnas.87.13.5139
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发表时间：
1990-07-01
影响因子：
11.1
通讯作者：
RUSSELL, P
中科院分区：
文献类型：
--
作者：
SADHU, K;REED, SI;RUSSELL, P
在体细胞周期期间进入有丝分裂是响应于监测DNA复制的完成、核基因组的完整性以及在细胞周期期间可能的细胞质量的增加的信号而调节的。据推测，这种细胞周期控制的操作涉及限速有丝分裂诱导剂的逐渐积累，当它们的细胞浓度达到临界水平时触发核分裂。我们已经克隆了一个人类基因，我们称之为CDC 25，其产物可能起有丝分裂诱导剂的作用。该人类基因编码预测分子量为53，000道尔顿的蛋白质，其C-末端结构域与裂殖酵母cdc 25+有丝分裂诱导剂共享约37%的序列同一性。人类CDC 25基因拯救了不能启动有丝分裂的裂变酵母温度敏感（ts）cdc 25 ts突变体的缺陷。在HeLa细胞中，CDC 25 mRNA水平在G1期非常低，并且随着细胞向M期进展而增加至少4倍。这些数据表明，在人类细胞中，在分裂酵母，积累的CDC 25有丝分裂诱导剂在G2期可能发挥关键作用，在调节有丝分裂的时间。
Entry into mitosis during the somatic cell cycle is regulated in response to signals that monitor the completion of DNA replication, the integrity of the nuclear genome, and possibly, the increase in cellular mass during the cell cycle. It has been postulated that the operation of this cell cycle control involves the gradual accumulation of rate-limiting mitotic inducers, which trigger nuclear division when their cellular concentration reaches a critical level. We have cloned a human gene, which we call CDC25, whose product may function as a mitotic inducer. This human gene encodes a protein with a predicted molecular mass of 53,000 daltons whose C-terminal domain shares about 37% sequence identity with the fission yeast cdc25+ mitotic inducer. The human CDC25 gene rescues the defect of a fission yeast temperature-sensitive (ts) cdc25ts mutant that is unable to initiate mitosis. In HeLa cells CDC25 mRNA levels are very low in G1 and increase at least 4-fold as cells progress towards M phase. These data suggest that in human cells, as in fission yeast, the accumulation of CDC25 mitotic inducer during G2 may play a key role in regulating the timing of mitosis.