Inhibition of replication initiation of damaged DNA by RB1/E2F1

During S phase of the cell cycle, RB1 is dephosphorylated by the PP2A protein phosphatase complex. Unphosphorylated RB1 associates with DNA damage sites in S phase, preventing initiation of DNA replication from these sites (Knudsen et al. 2000, Avni et al. 2003).

在细胞周期的S期，RB1蛋白由PP2A蛋白磷酸酶复合体进行去磷酸化。去磷酸化的RB1蛋白在S期与DNA损伤位点结合，从而防止从这些位点启动DNA复制（Knudsen等，2000年，Avni等，2003年）。