Buchkovich K, Duffy L A, Harlow E
Cold Spring Harbor Laboratory, New York 11724.
Cell. 1989 Sep 22;58(6):1097-105. doi: 10.1016/0092-8674(89)90508-4.
p105-RB is the product of the retinoblastoma tumor suppressor gene. It is a nuclear phosphoprotein hypothesized to act as an inhibitor of cellular proliferation, yet surprisingly it is present in actively dividing cells. To look for changes in p105-RB that may regulate its activity during the cell cycle, we generated synchronized cell populations and followed their progression through the cell cycle. p105-RB is synthesized throughout the cycle, but is phosphorylated in a phase-specific manner. In the G0 and G1 phases of the cell cycle, an unphosphorylated species of the protein is the only detectable form, whereas in the S and G2/M phases, multiple phosphorylated species of p105-RB are detected.
p105-RB是视网膜母细胞瘤肿瘤抑制基因的产物。它是一种核磷蛋白，据推测可作为细胞增殖的抑制剂，但令人惊讶的是，它存在于活跃分裂的细胞中。为了寻找可能在细胞周期中调节其活性的p105-RB的变化，我们生成了同步化的细胞群体，并跟踪它们在细胞周期中的进程。p105-RB在整个周期中都有合成，但以阶段特异性的方式被磷酸化。在细胞周期的G0和G1期，该蛋白的未磷酸化形式是唯一可检测到的形式，而在S期和G2/M期，则检测到p105-RB的多种磷酸化形式。
