Martelli A M, Gilmour R S, Falcieri E, Manzoli F A, Cocco L
Istituto di Anatomia Umana Normale, Università di Bologna, Italy.
Exp Cell Res. 1989 Nov;185(1):191-202. doi: 10.1016/0014-4827(89)90048-7.
When Swiss 3T3 fibroblasts are treated with a combination of IGF-I2 and bombesin at mitogenic concentrations, in vivo phosphorylation of some nuclear proteins occurs within 45-90 min. Among these proteins, histone H1 and a 0.75 M PCA soluble polypeptide with an apparent Mr of 21,000, as revealed by electrophoretic analysis, are phosphorylated in vitro by protein kinase C in isolated nuclei purified from 3T3 cells treated for 90 min with IGF-I and bombesin. Since these phosphorylative events follow the earlier changes, recently demonstrated, in nuclear polyphosphoinositide metabolism induced by the same mitogen combination, it seems possible that these two phenomena are related to each other and trigger the synthetic machinery responsible for replicating DNA.
当瑞士3T3成纤维细胞用促有丝分裂浓度的IGF-I2和蛙皮素联合处理时，一些核蛋白在45 - 90分钟内发生体内磷酸化。在这些蛋白质中，经电泳分析显示，组蛋白H1和一种表观分子量为21,000的0.75M PCA可溶性多肽，在从用IGF-I和蛙皮素处理90分钟的3T3细胞中纯化得到的分离细胞核中，可被蛋白激酶C体外磷酸化。由于这些磷酸化事件遵循了最近所证实的、由相同促有丝分裂原组合诱导的核多磷酸肌醇代谢的早期变化，所以这两种现象似乎相互关联，并触发负责DNA复制的合成机制。
