SIAH1介导TRB3的泛素化和降解

SIAH1 Mediated Ubiquitination and Degradation of TRB3

目的利用酵母回转实验和免疫共沉淀实验验证SIAHI和TRB3之间的相互作用并探讨其功能相关性。方法将全长形式的TRB3基因和SIAH1基因分别克隆入酵母表达载体pDBLeu和pPC86中，共转化至MaV203酵母感受态细胞，验证其相互作用，然后分别构建至真核表达载体pCMV—Myc和pFLAG—CMV-2中，采用免疫共沉淀实验进行进一步验证。通过体内泛素化实验检测SIAH1对TRB3蛋白稳定性及泛素化修饰的影响。结果通过在酵母细胞中的回转实验和HEK293rr细胞中的免疫共沉淀实验证实了TRB3与SIAH1之间的相互作用。通过体内泛素化实验证实了S1AH1介导了TRB3的泛素化修饰和降解。结论证实了TRB3与SIAH1之间的相互作用并发现SIAH1介导了TRB3的泛素化修饰和降解，为TRB3蛋白的功能研究提供了新的线索。

Objective To validate the interaction between SIAH1 and TRB3 and explore their functional relationship. Methods Full-length TRB3 and SIAH1 were sub-cloned into yeast expression vectors pDBLeu and pPC86 respectively, and then co-transformed into MaV203 for retransfor- marion test. In addition, Mammalian expression vectors expressing respective TRB3 and SIAH1 were constructed. Interaction of TRB3 and SIAHI was detected by co-immunoprecipitation assay. The effects of overexpressed SIAH1 on TRB3 stability and ubiquitination were investigated by in-vivo ubiquitination assay. Results SIAH1 was associated with TRB3 in both yeast and mammalian cells. Importantly, SIAH1 targeted TRB3 for proteasome-dependent degradation. Conclusion SIAH1 mediated ubiqutination and degradation of TRB3, suggestive for further functional study of TRB3.