蛋白激酶C与细胞周期

Protein kinase C and cell cycle

近年的研究表明， ＰＫＣ涉及到细胞的周期调节。在酵母细胞和哺乳动物细胞均发现 ＰＫＣ参与细胞周期调控，从而提示 ＰＫＣ可能在进化上是一种保守的细胞周期调节子。一般认为 ＰＫＣ在两个点上对细胞周期起作用，即 Ｇ１期和 Ｇ２期到 Ｍ期的过渡期（Ｇ２／Ｍ）。在 Ｇ１期， ＰＫＣ分别在早 Ｇ１期和晚Ｇ１期作用有所不同，主要作用表现在使细胞停留在Ｇ１期的中末阶段，这一过程，主要涉及到抑制肿瘤抑制因子——成视网膜细胞瘤（Ｒｂ）蛋白的磷酸化。 ＰＫＣ的主要作用是降低周期素依赖激酶ＣＤＫ２的活性、降低周期素 Ｅ和 Ａ的表达和增加周期素依赖的周期抑制蛋白 ｐ２１ＷＡＦ１和 ｐ２７ＫＩＰ１的表达；在 Ｇ２／Ｍ期， ＰＫＣ对细胞周期的调节主要与 Ｃｄｃ２（ＣＤＫ１）的活性抑制有关。

Protein kinase C(PKC) is involved in diverse cellular function. Recently, that PKC on cell cycle control has began to emerge in both yeast and mammals,which suggest that PKC is a conserved regulator of cell cycle in evolution progression. PKC regulate cell cycle at two sites, G1 and G2/M transition. During G1 progression, PKC has different effects on early and later phases, and overall effect is to inhibit cell cycle at mid to late G1 through blocking phosphorylation of tumor suppressor retinoblastoma(Rb) protein. Furthermore, PKC reduce activity of cyclin-dependent kinase CDK2, inhibit expression of cyclin E and A and augment produce of cyclin-dependent inhibitors, p21WAF1 and p27KIP1; During G2/M boundary, PKC mainly inhibit activity of Cdc2 and prevent cell from entering M. In this paper, we will review PKC on cell cycle control.