转录因子Sox2 SUMO修饰位点突变体的构建及真核表达

目的:构建Sox2及突变体Sox2 K247R的真核表达载体, 并在293FT细胞中表达.方法:以含有Sox2基因全长的馈赠质粒为模板, 用循环延伸PCR法得到该基因的突变体Sox2 K247R, 并将野生型及突变型基因定向亚克隆到真核表达载体pCMV-HA上.得到的重组质粒经限制性内切酶消化和DNA测序鉴定.其后用脂质体包埋法将pCMV-HA-Sox2及pCMV-HA-Sox2 K247R分别单独转染或与pCMV-Myc-SUMO1共转染293FT细胞.采用Western blot分析蛋白表达情况及SUMO修饰情况.结果:经酶切和DNA序列测定, 重组子序列正确, 突变体第247位密码子由AAG转变为CGG.Western blot结果显示野生型及突变型的Sox2都在细胞内得到了很好的表达, SUMO修饰位点突变后, Sox2不能与SUMO蛋白结合.结论:Sox2野生型及突变型真核表达载体构建成功, 在蛋白水平体现了SUMO修饰的差异性.

Construction and expression of vector encoding Sox2 with mutated SUMO accepter site

AIM:To construct eukaryotic expression plasmids encoding Sox2 and Sox2 K247R and identify their expression and SUMOylation. METHODS: With gift plas-mid encoding Sox2 gene as a template, Sox2 K247R was obtained by overlapping extension PCR, followed by construction of pCMV-HA-Sox2 and pCMV-HA-Sox2 K247R. After enzyme digestion analysis and DNA sequencing, these two constructs were transfected or co-transfected with pC-MV-Myc-SUMO1 into 293 FT cells by lipofectin method. Western blot was employed to analyze expression and SUMO ylation of Sox2. RESULTS: It was revealed that eukaryotic expression vectors were constructed with correct sequence, where in mutant Sox2, the AAG codon was switched to CGG codon. Western blot results showed that good expression of both wt and mut Sox2, of which the latter could not be modified by SUMO1. CONCLUSION: Successful construction and expression of Sox2 and Sox2 K247R. Sox2 could be SUMO lyated in vitro but Sox2 K247R not.