目的:构建3*Flag-hPAK4真核表达质粒,证实融合蛋白在细胞内的表达与定位,并纯化PAK4蛋白。方法:提取人乳腺癌细胞MCF-7 mRNA,反转录为cDNA。PCR扩增hPAK4全长编码基因,亚克隆至含有3*Flag标签的真核表达载体中。将构建的重组质粒测序并转染到非洲绿猴肾成纤维细胞COS7中,提取细胞蛋白进行Western blotting检测,同时利用共聚焦激光扫描显微镜观察3*Flag-hPAK4在COS7细胞内定位。使用免疫沉淀的方法纯化PAK4蛋白。结果:hPAK4全长基因序列克隆到了真核表达载体3*Flag中,酶切鉴定片段为1 800 bp。Western blotting检测到了融合蛋白3*Flag-hPAK4的表达,分子质量约为68 kDa,3*Flag-hPAK4在COS7细胞中表达定位在细胞浆中,成功纯化了PAK4蛋白。结论:成功地构建了3*Flag-hPAK4真核表达质粒,同时鉴定了3*Flag-hPAK4融合蛋白的表达,并纯化了PAK4蛋白。3*Flag-hPAK4蛋白主要定位在细胞浆中。
Objective: To construct the expression plasmid of 3*Flag-hPAK4 and identify its recombinant protein expression and localization,and purify the Pak4 protein.Methods: Total RNA was extracted from human breast cancer MCF-7 cells.The hPAK4 coding sequence was amplified by polymerase chain reaction(PCR) method and subcloned into 3*Flag vector.After the target region was sequenced,the plasmid was transfected into COS7 cell line.The expression of the recombinant plasmid in COS7 cells was proved by Western blotting.The localization of 3*Flag-hPAK4 in COS7 cells was observed by using laser scanning confocal microscopy.The hPak4 protein was purify by immunoprecipitate.Results: hPAK4 had been constructed into expressing vector 3*Flag successfully.The length of the fragment was 1 800 bp,identified by restriction enzymes digestion.The expression of 3*Flag-hPAK4 fusion protein was detected by Western blot,with a molecular weight 68 kDa,was pulled down by Flag antibody,its localization in the cytoplasm.Conclusion:The recombinant plasmid is successfully cloned into eukaryotic expressing vector,the expression of 3*Flag-hPAK4 fusion protein is identified and pulled down by Flag antibody,it was expressed in cytoplasm.