Dobrowolski S F, Stacey D W, Harter M L, Stine J T, Hiebert S W
Department of Molecular Biology, Cleveland Clinic Foundation, Ohio 44195-5178.
Oncogene. 1994 Sep;9(9):2605-12.
E2F is a cellular transcription factor that is regulated during the cell cycle through interactions with the product of the retinoblastoma susceptibility gene (RB1) and the pRb-like p107 and p130 proteins. Analysis of mutations within both adenovirus E1A and pRb, which affected their ability to regulate cellular proliferation and alter E2F activity, suggested that E2F may play a role in cell cycle progression. Microinjection of a GST-E2F-1 fusion protein into quiescent Balb/c 3T3 cells induced DNA synthesis whereas co-injection of GST-E2F-1 and GST-E2F(95-191) protein, encoding only the DNA binding domain of E2F-1, blocked the induction of S-phase. While E1A likely targets multiple cellular pathways, co-injection of the GST-E2F(95-191) dominant inhibitory protein with 12S E1A protein blocked E1A-mediated induction of DNA synthesis, suggesting that the E2F-dependent pathway is dominant. Analysis of the interval required for microinjected quiescent cells to enter S-phase indicated that E2F-1 acted faster than either E1A or serum.
E2F是一种细胞转录因子，在细胞周期中通过与视网膜母细胞瘤易感基因（RB1）产物以及pRb样p107和p130蛋白相互作用来调节。对腺病毒E1A和pRb内影响其调节细胞增殖能力及改变E2F活性的突变进行分析，提示E2F可能在细胞周期进程中发挥作用。将GST-E2F-1融合蛋白显微注射到静止的Balb/c 3T3细胞中可诱导DNA合成，而同时注射GST-E2F-1和仅编码E2F-1 DNA结合结构域的GST-E2F(95 - 191)蛋白则可阻断S期的诱导。虽然E1A可能靶向多种细胞途径，但将GST-E2F(95 - 191)显性抑制蛋白与12S E1A蛋白同时注射可阻断E1A介导的DNA合成诱导，这表明E2F依赖性途径起主导作用。对显微注射的静止细胞进入S期所需时间间隔的分析表明E2F-1的作用比E1A或血清更快。
