Roberts S B, Segil N, Heintz N
Howard Hughes Medical Institute, Laboratory of Molecular Biology, Rockefeller University, New York, NY 10021.
Science. 1991 Aug 30;253(5023):1022-6. doi: 10.1126/science.1887216.
Orderly progression through the somatic cell division cycle is accompanied by phase-specific transcription of a variety of different genes. During S phase, transcription of mammalian histone H2B genes requires a specific promoter element and its cognate transcription factor Oct1 (OTF1). A possible mechanism for regulating histone H2B transcription during the cell cycle is direct modulation of Oct1 activity by phase-specific posttranslational modifications. Analysis of Oct1 during progression through the cell cycle revealed a complex temporal program of phosphorylation. A p34cdc2-related protein kinase that is active during mitosis may be responsible for one mitotic phosphorylation of Oct1. However, the temporally controlled appearance of Oct1 phosphopeptides suggests the involvement of multiple kinases and phosphatases. These results support the idea that cell cycle-regulated transcription factors may be direct substrates for phase-specific regulatory enzymes.
体细胞分裂周期的有序进行伴随着多种不同基因的阶段特异性转录。在S期，哺乳动物组蛋白H2B基因的转录需要特定的启动子元件及其同源转录因子Oct1（OTF1）。在细胞周期中调节组蛋白H2B转录的一种可能机制是通过阶段特异性翻译后修饰直接调节Oct1活性。对细胞周期进程中Oct1的分析揭示了一个复杂的磷酸化时间程序。一种在有丝分裂期间活跃的与p34cdc2相关的蛋白激酶可能负责Oct1的一次有丝分裂磷酸化。然而，Oct1磷酸肽的时间控制出现表明涉及多种激酶和磷酸酶。这些结果支持这样一种观点，即细胞周期调节的转录因子可能是阶段特异性调节酶的直接底物。
