Scribble调控β-catenin的入核  

Scribble Regulates the Nucleus Entry of β-catenin

作　　者：李苏瑞[1] 牛晓峰[1] 陈铭[1] 

机构地区：[1]中国科学院上海生命科学研究院生物化学与细胞生物学研究所,上海200031

出　　处：《中国细胞生物学学报》2010年第3期433-438,共6页Chinese Journal of Cell Biology

基　　金：国家自然科学基金委(No.30771960)资助项目~~

摘　　要：Scribble(Scrib)是富含亮氨酸重复序列及PDZ结构域蛋白(LAP)家族的一员,以脚手架蛋白的方式与多种分子相结合并整合多种信号通路协同发挥作用。β-catenin是一种多功能蛋白质,在介导细胞粘附及信号转导中起中心分子作用。为研究Scrib与β-catenin间是否存在联系及何种联系,我们做了一系列实验。研究发现,如果HEK293/HEK293T细胞中过表达Scrib,β-catenin的转录活性报告基因LEF-1-1uciferase的活性则显著减弱;而如果HEK293/HEK293T细胞中稳定下调Scrib,LEF-1-luciferase的活性则显著增强。表明Scrib可抑制β-catenin的转录活性。我们同时利用免疫共沉淀(Co-IP)实验发现Scrib与β-catenin存在特异结合作用。另外,细胞组分分离实验表明HEK293/HEK293T细胞中稳定下调Scrib,细胞中β-catenin蛋白总量不变,而胞浆及胞核内β-catenin量增多即表明Scrib可抑制β-catenin的入核。本研究在分子机制上表明Scrib可通过与β-catenin的结合,抑制β-catenin入核,从而影响β-catenin的下游调控基因。Scribble （Scrib） is a member of the leucinerich repeat and PDZ containing protein （ LAP ） family, connected to the membrane. Scrib plays a variety of roles by combinating with many protein molecules and integrating multiple signaling pathways in scaffolding protein ways. β-catenin a multifunctional protein, plays central roles in mediating cell adhesion and signal transduction. To study what relationship and regulative mechanism between Scrib and β-catenin, we have done a series of experiments. We found that after Scrib was overexpressed in HEK293/ HEK293T, the transcriptional activity of β-catenin, the LEF-1-luciferase activity of the reporter gene was significandy reduced; while after Scrib was stably reduced in the HEK293/HEK293T, the LEF-l-luciferase activity of the reporter gene was significantly increased. So we can conclude that Scrib can inhibit the transcriptional activity of β- catenin. We also found that Scrib could specially interact with β-catenin by endogenous Co-IP. Furthermore, in cellular separation experiments of HEK293/293T, we found after Scrib was stably reduced, total cellular β-catenin wasn＇t affected, while the cytoplasmic and nucleus β-catenin was increased. We showed Scrib could inhibit the nucleus entry of β-catenin. We herein demonstrate that the molecular mechanism between hScrib and β-catenin： Scrib could interact with β-catenin and inhibit the nucleus entry of β-catenin, thus inhibiting the downstream gene regulation of β-catenin.

关 键 词：SCRIBBLE Β-CATENIN LEF-1-luciferase 入核 

分 类 号：R363[医药卫生—病理学]