Shawver L K, Behrens C B, Deuel T F
Department of Medicine, Jewish Hospital, Washington 4niversity Medical Center, St. Louis, Missouri 63110.
Biochem Biophys Res Commun. 1989 Jun 30;161(3):1118-25. doi: 10.1016/0006-291x(89)91358-2.
We report the initial characterization of pp64, a nuclear protein recognized by anti-PDGF antisera and uniquely phosphorylated when intact NRK fibroblasts were exposed to PDGF. Neither DNase nor RNase released pp64 from nuclei and pp64 was only partially extracted from nuclei of NRK cells with NaCl; detergents were required for complete extraction. The estimated half-life of pp64 from normal and transformed NRK cells was approximately 6 hrs. The rapid and unique PDGF stimulated phosphorylation of pp64 identifies a previously uncharacterized nuclear phosphoprotein, and a potentially novel signal transduction pathway from the cell surface to the nucleus which may be important in initiating nuclear events associated with DNA synthesis and cell division.
我们报告了pp64的初步特性，它是一种可被抗血小板衍生生长因子（PDGF）抗血清识别的核蛋白，当完整的NRK成纤维细胞暴露于PDGF时会发生独特的磷酸化。脱氧核糖核酸酶（DNase）和核糖核酸酶（RNase）均不能从细胞核中释放出pp64，并且pp64仅能被氯化钠从NRK细胞核中部分提取出来；完全提取则需要去污剂。正常和转化的NRK细胞中pp64的估计半衰期约为6小时。pp64被PDGF快速且独特地刺激磷酸化，这确定了一种先前未被表征的核磷蛋白，以及一条从细胞表面到细胞核的潜在新信号转导途径，该途径可能在启动与DNA合成和细胞分裂相关的核事件中起重要作用。
