中文摘要：

目的探讨hSav1（human salvador1）和Mst1（MammalianSTE20-like 1）存在的相互作用，为进一步研究Mst1的功能及相关机制奠定基础。方法以Mst1 cDNA全长构建诱饵蛋白载体pGBKT7-Mst1，并对其自身转录活性进行鉴定，利用酵母双杂交系统筛选人胎肝文库，挑选单克隆，从而初步筛选出与Mst1相互作用的蛋白。然后构建初步筛选出的蛋白hSav1的载体pCMV-HAhSav1，与蛋白Mst1的载体pcDNA／4TO-Flag-Mst1共转染HEK293T细胞，利用相应抗体做二者的免疫共沉淀，以验证蛋白hSav1和Mst1之间的相互作用。其次构建pEGFP-hSav1质粒转染HEK293T，利用免疫荧光观察二者在细胞内的定位。结果以Mst1为诱饵蛋白在人胎肝文库筛选到包括hSav1在内的与之存在相互作用的蛋白。免疫共沉淀结果显示，hSav1蛋白可以在FLAG抗体的免疫沉淀物中检测出来，同样在hSav1抗体的免疫沉淀物中也能检测到蛋白Mst1。免疫荧光的结果显示二者荧光在细胞内存在共定位，二者的荧光可充分融合。结论蛋白hSav1与Mst1在哺乳细胞内存在某种相互作用，为进一步研究Mst1的功能及相关机制提供了线索。

英文摘要：

Objective To elucidate whether hSav1 binds to Mst1. Methods The cDNA of Mst1 was cloned into the bait protein plasmid. The positive clones were screened out from human fetal liver cDNA library by yeast two-hybrid system. Plasmids pCMV-HA-hSav1 and pcDNA/4TO-Flag-Mst1 were constructed and then the studies of binding in vivo were carried out after co-transfection of the constructs into human embryonic kidney （HEK293T） cells. Triple immunofluorescent labeling for hSav1, Mst1 and nucleus was performed to determine the subcellular localization of them. Results Through the yeast two-hy- brid screening, hSav1 was identified as one of the molecules that interacted with Mst1. The studies of binding in vivo revealed that hSav1 could be detected from the immunoprecipitation complex of anti-FLAG and Mst1 from the immunopreeipitation complex of anti-hSav1, respectively. The immunofluoreseent labeling showed that hSav1 and Mst1 had the same localization in cells. Conclusion hSav1 is a newly identified protein that interacts with Mst1.