人CREB4转核机制的初步研究  

Primary Study of CREB4 Translocation Mechanism from Cytoplasm to Nucleus

作　　者：刘永强[1] 倪晓华[1] 周丹[1] 王鑫[1] 郭伟伟[1] 

机构地区：[1]华东师范大学生命科学学院,上海200062

出　　处：《华东师范大学学报（自然科学版）》2007年第2期104-110,共7页Journal of East China Normal University(Natural Science)

基　　金：上海市自然科学基金(04ZR14040)

摘　　要：cAMP反应元件结合蛋白(cAMP response element-binding proteins,CREB)是一个哺乳动物转录因子家族,通过cAMP反应元件(cAMP response element,CRE)调节cAMP和钙离子依赖性基因的表达.CREB4是CREB转录因子家族的一员.经酵母双杂交筛选人胎脑文库发现CREB4215-279aa可能与核转运因子kayopherinα2相互作用,提示karyopherinα2可能参与CREB4的跨膜转运过程.亚细胞定位结果显示,CREB4全长定位于细胞质,而缺失C端假定转膜结构域的CREB41-279aa蛋白则转移至细胞核内.荧光共定位进一步显示,CREB4和karyopherinα2共定位于细胞质中,CREB41-279aa和karyopherinα2共定位于细胞核中.结果提示C端被切除之后,CREB4被karyopherinα2转运到核内发挥转录作用.cAMP response element-binding（CREB） proteins are a family of mammalian transcription activators that mediate cAMP and calcium-dependent gene expression through the cAMP response element （CRE）. CREB4 is a novel member of the human CREB family. Yeast two-hybrid system revealed that karyopherinα2 may associate with CREB4^215-279aa. Subcellular location of CREB4 and CREB4^1-279aa showed that the GFP-CREB4 fusion protein was localized in cytoplasm, whereas the fusion protein of GFP-CREB4^1-279aa was translocated in nucleus. Our experiments further showed that CREB4 and karyopherinα2 were co-located in cytoplasm, but CREB4^1-279aa and karyopherinα2 were co-located in nucleus. These results suggested that first Cterminal was cleaved and then CREB4was carried into nucleus by karyopherinα2 to activate gene transcription.

关 键 词：CREB4 酵母双杂交 荧光共定位 kayopherina2 

分 类 号：Q291[生物学—细胞生物学]