钙结合蛋白S100A2对Wnt/β-catenin信号途径活性的上调作用  

S100 calcium-binding protein A2 upregulates the activity of Wnt/β-catenin signaling pathway

作　　者：赖天霞[1] 苗静琨[1] 左国伟[1] 何焕玲[1] 李星星[1] 卫佳[1] 吴丽美[1] 寇小琴[1] 何通川 周兰[1] 

机构地区：[1]重庆医科大学生物医学工程系,重庆400016 [2]Molecular Oncology Laboratory,Department of Surgery,The University of Chicago Medical Center

出　　处：《第三军医大学学报》2008年第16期1545-1548,共4页Journal of Third Military Medical University

基　　金：国家自然科学基金(30340039);教育部"春晖计划"合作项目(2003);教育部留学回国人员科研启动基金(2004)~~

摘　　要：目的研究钙结合蛋白S100A2对Wnt/β-catenin信号途径活性的影响,并探讨其可能的机制。方法原核诱导表达GST-hS100A2,经纯化后加入骨肉瘤细胞株MG63和人结肠癌细胞株HCT116的培养液中,Western blot检测细胞中β-catenin含量的变化;荧光素酶活性分析法检测S100A2对HEK293细胞中β-catenin/TCF4活性的影响;以表达GSK-3β、DVL、Axin的相应质粒分别转染HEK293细胞,GST-Pulldown/Western blot实验检测S100A2与这些蛋白质和β-catenin之间的相互作用。结果S100A2使MG63和HCT116细胞中β-catenin含量增加、β-catenin/TCF4活性增强;S100A2分别与β-catenin和GSK-3β之间存在相互作用,而与DVL和Axin之间则未发现相互作用。结论S100A2可以上调Wnt/β-catenin信号途径的活性,其机制可能涉及S100A2与β-catenin和GSK-3β之间的相互作用。Objective To investigate the effects of calcium-binding protein S100 A2 on Wnt/β-catenin signaling pathway and its mechanisms. Methods Human osteosarcoma cell line MG63 and human colon cancer cell line HCT116 were treated with recombinant fusion protein GST-hS100A2 that was expressed in E. coli and purified. β-catenin was quantified by Western blot and the effects of S100A2 on the β-catenin/TCF4 activity was analyzed by luciferase activity assay. The interactions between S100A2 and β-catenin/GSK-3β/DVL/ Axin were detected by GST-Pulldown and Western blot. Results The β-catenin level in MG63 and HCT cells treated with GST-hS100A2 increased significantly as compared with that in the GST control group （P 〈 0. 01 ）. The luciferase activity in HEK 293 cells transfected with pTOP-Luc and then treated with GST-hS100A2 in- creased by 12.3 fold as compared with that in the GST control group （P 〈0. 01 ）. The interactions between GST-hS100A2 and [3-catenin/GSK-3β were verified by GST-Pulldown/Western blot, and no interaction was found between GST-hS100A2 and Axin/DVL. Conclusion S100A2 can upregulate the activity of Wnt/β-catenin signaling pathway and its mechanism may involve in the interactions between S100A2 and β-catenin/GSK-3β.

关 键 词：S1 00A2 Wnt/β-catenin信号途径 蛋白质相互作用 

分 类 号：Q513[生物学—生物化学] R394.3[医药卫生—医学遗传学]