Krek W, Nigg E A
Swiss Institute for Experimental Cancer Research (ISREC), Epalinges s/Lausanne.
EMBO J. 1989 Oct;8(10):3071-8. doi: 10.1002/j.1460-2075.1989.tb08458.x.
The cdc2 protein kinase plays a key role in controlling the eukaryotic cell cycle. We have isolated a cDNA clone for the chicken homolog of the cdc2 gene, raised antibodies against the corresponding protein, and studied the expression of cdc2 mRNA and protein during chicken embryonic development. The protein encoded by the chicken cdc2 cDNA shares extensive structural homology with cdc2 gene products from other species. Moreover, when expressed in fission yeast, the chicken cdc2 kinase is able to rescue a temperature-sensitive (ts) cdc2 mutant, demonstrating that it is functional as a cell cycle regulator. By Northern analysis and immunoblotting, we found that in total embryos both cdc2 mRNA and protein levels decreased substantially between day 3 and day 11 after egg laying, and no significant amounts of either cdc2 mRNA or protein were detected in adult liver, brain, heart or skeletal muscle. These data indicate the existence of a coarse correlation between the abundance of cdc2 mRNA and the proliferative state of a given tissue. Interestingly, however, when examining individual embryonic tissues, no correlation was observed between levels of cdc2 mRNA and protein, suggesting that cdc2 expression in developing chicken may be regulated at multiple levels.
细胞周期蛋白依赖性激酶2（cdc2）在控制真核细胞周期中起关键作用。我们分离出了鸡源cdc2基因同源物的cDNA克隆，制备了针对相应蛋白质的抗体，并研究了cdc2 mRNA和蛋白质在鸡胚胎发育过程中的表达情况。鸡源cdc2 cDNA编码的蛋白质与其他物种的cdc2基因产物具有广泛的结构同源性。此外，当在裂殖酵母中表达时，鸡源cdc2激酶能够挽救温度敏感型（ts）cdc2突变体，表明它作为细胞周期调节因子具有功能。通过Northern印迹分析和免疫印迹法，我们发现，在整个胚胎中，产卵后第3天到第11天期间，cdc2 mRNA和蛋白质水平均大幅下降，并且在成年鸡的肝脏、大脑、心脏或骨骼肌中未检测到大量的cdc2 mRNA或蛋白质。这些数据表明，cdc2 mRNA丰度与特定组织的增殖状态之间存在大致的相关性。然而，有趣的是，在检查单个胚胎组织时，未观察到cdc2 mRNA水平与蛋白质水平之间的相关性，这表明发育中的鸡体内cdc2的表达可能在多个水平上受到调控。
