【摘要】 信号转导和转录激活蛋白Stat3在细胞的生长、分化、存活和运动过程中扮演重要角色。通过免疫细胞化学染色 ,免疫沉淀结合免疫蛋白质印迹法 ,以及瞬时转染由Stat3特异识别DNA元件所指导的报道基因等技术 ,证明COS7细胞中存在活性Stat3蛋白的表达。Stat3cDNA和报道基因在COS7细胞中的共转染实验表明 ,外源的Stat3蛋白具有DNA结合活性 ,并可增强报道基因的表达。同时 ,过量表达Stat3的COS7细胞呈现显著的细胞形态变化 ,如细胞体积增大、胞体伸出突起 ,有些突起有分枝和伪足。这些结果提示 ,Stat3蛋白在细胞的粘附和迁移 ,以及细胞骨架的重建过程中可能具有重要功能。更多还原

【Abstract】 Signal transducer and activator of transcription 3 (STAT3) plays a central role in mediating signals related to cell growth, differentiation, survival and movement. In this report, the results of immunocytochemistry and Western blot analysis showed that the active form of Stat3 protein existed in COS7 cells. The endogenous Stat3 protein could also induce the expression of m67 sequence directed reporter genes. The transient transfection of Stat 3 cDNA into COS7 cells increased Stat3 protein level and the expression of the reporter gene. The overexpression of Stat3 protein in COS7 cells caused prominent cell morphological changes. These cells had a much larger cell body, extended long processes with branches, lamellipodia and filopodia. These results suggest that Stat3 protein may play important roles in cell adhension, migration and cytoskeleton reorganization.更多还原