人eRF3a与survivin相互作用的结构域分析

Analysis on the Interacting Domain of Human eRF3a with Survivin

第二类肽链释放因子eRF3(eukaryotic polypeptide release factor)是一种GTPase,它促进第一类肽链释放因子eRF1的释放活性,并与细胞周期调控、细胞骨架组装、细胞凋亡和肿瘤形成等过程相关。哺乳动物细胞中eRF3有两种——eRF3a和eRF3b,分别由GSPT1和GSPT2(G1 to S phase transition 1/2)基因编码。生存素(survivin)是迄今发现的最强有力的凋亡抑制因子,具有独特的结构和复杂的功能,不仅可以抑制细胞凋亡,还参与细胞有丝分裂、血管的生成等过程。eRF3和survivin都与细胞周期和细胞凋亡的调控相关。该实验室的前期研究表明,eRF3和survivin具有相互作用关系。该研究进一步对eRF3a进行截短突变,采用酵母双杂交和pull-down两种分析方法依次验证eRF3a(1-72aa)和eRF3a(1-36aa)与survivin的相互作用关系。结果表明,eRF3a(1-72aa)和eRF3a(1-36aa)均可以与survivin相互作用,由此确定eRF3a与survivin相互作用的最小结构域位于其N末端1-36aa之间,从而为进一步证实eRF3a的N端结构域与survivin协同作用参与细胞周期和细胞凋亡的调控提供了数据支持。

In mammals, two genes, GSPTI and GSPT2, encode two distinct forms of Class II polypeptide release factor eRF3, eRF3a and eRF3b, respectively, eRF3 is a GTPase associated with eRF1 in a complex that me- diates the release of nascent polypeptides. Some studies indicated that eRF3 was involved in cell cycle regulation, cytoskeleton, apoptosis, and tumorigenesis. Survivin is the most powerful inhibitor of apoptosis gene ever found. In additional, survivin is involved in cell mitosis and angiogenesis etc. Both eRF3 and survivin are associated with the regulation of cell cycle and apoptosis. Our previous studies demonstrated that eRF3 interacted with survivin in vivo and in vitro. In this study, we have truncated eRF3a, and verified the interaction between eRF3a（1-72aa）/eRF3a（1- 36aa） and survivin by using the yeast two-hybrid and pull-down assay, respectively. The results suggested that both eRF3a（1-72aa） and eRF3a（1-36aa） could interact with survivin, therefore, we concluded that their minimal interac- tion domain located amongst 1-36aa of eRF3a. Accordingly, the results provided the data supporting for further con- firmation of the N terminal domain of eRF3 cooperating with survivin involved in cell cycle and apoptosis regulation.