转录因子COUP-TFII对端粒酶活性的抑制及其相互作用蛋白的分离和鉴定

The transcription factor COUP-TFII inhibits telomerase activity and the separation and identification of its interactional proteins

端粒酶催化亚基hTERT的转录调控是端粒酶活性调节的关键步骤 .实验分离和克隆了参与hTERT转录调控的转录因子COUP TFII,分析了其对HeLa细胞端粒酶活性的生物学效应 ,并分离和鉴定了与其相互作用的蛋白质 .结果表明在以hTERT启动子为诱饵的酵母单杂交体系中 ,COUP TFII可以与hTERT启动子结合 ;得到了纯度高达98%的COUP TFII融合蛋白 ,并且其结合于hTERT启动子 2 0 1～ +35区段 ,抑制HeLa细胞端粒酶的活性 ;从HeLa细胞核蛋白中分离到了 2种与COUP TFII相互作用的蛋白质 .研究初步揭示了COUP TFII在细胞分化和肿瘤转化过程中的参与途径和调控机制 ,为开启以端粒酶为靶目标的肿瘤治疗奠定了基础 .

hTERT transcription is the key step in the regulation of telomerase activity. The transcription factor COUP-TFII which involved in regulating the transcription of hTERT was identified and cloned, and its role in telomerase activity in HeLa cells was studied. Its interactional proteins were also separated from HeLa cell nuclear extracts in the present research. COUP-TFII was proved to interact with hTERT promoter in hTERT promoter-based yeast one-hybrid assay. COUP-TFII fusion protein was purified to the fineness ratio up to 98% and it could firmly bind to -201 to +35 fragment of hTERT promoter, and inhibit telomerase activity; two proteins which interact with COUP-TFII were separated from HeLa cell nuclear extracts. The results provide a new clue to profile of COUP-TFII in cellular differentiation and cancer transformation,and will be useful to open up a new strategy for telomerase-targeted anticancer therapy.