目的　探讨转录因子 E2 F1在人视网膜色素上皮 (retinal pigment epithelium,RPE)细胞中的表达及活化。　方法　培养的人 RPE细胞经同步化后分为两组 :无血清组和含 2 0 %新生牛血清的血清组。采用 Western blot蛋白印迹法检测两组细胞中转录因子 E2 F1蛋白的表达。用凝胶迁移率变动分析法(EMSA)检测其与 DNA的结合活性。　结果　在 RPE细胞核抽提物中检测到相对分子质量为 6 0× 10 3的E2 F1蛋白 ,血清刺激使其表达增加 (P<0 .0 0 1)。EMSA分析示在血清刺激下 ,E2 F1核蛋白与 DNA的结合活性增强。　结论　转录因子 E2 F1存在于人 RPE细胞的细胞核中 ,血清刺激可诱导其表达增加 ,并增强其与 DNA的结合活性 ,发挥其调控基因转录的作用 Objective To investigate the expression and activation of transcription factor E2 F1 in human retinal pigment epithelium (RPE) cells. The cultured human RPE cells were divided into two groups after synchronization: serum-free group and serum group containing 20% ​​newborn calf serum. Western blot was used to detect the expression of E2F1 protein in the two groups of cells. The binding activity to DNA was examined by gel shift assay (EMSA). Results The E2 F1 protein with a relative molecular mass of 60 × 10 3 was detected in the nuclear extracts of RPE cells and the expression of E2 was increased by serum stimulation (P <0.01). EMSA analysis showed that the binding activity of E2 Fl nucleoprotein to DNA increased with serum stimulation. Conclusion The transcription factor E2 F1 exists in the nuclei of human RPE cells. Serum stimulation can induce its expression and enhance its binding activity with DNA, playing a role in its regulation of gene transcription