TNF-SP-EGFP融合蛋白的构建表达及亚细胞定位

目的探讨肿瘤坏死因子信号肽（TNF-SP）在哺乳动物细胞的表达和亚细胞定位。方法采用聚合酶链反应（PCR）技术，以TNF-SP-pcDNA3.0质粒为模板扩增TNF-SP基因，采用PCR产物的粘端克隆法，将TNF-SP定向克隆入pEGFP-N1的多克隆位点，构建TNF-SP-EGFP重组质粒，酶切，PCR检测，序列分析鉴定，采用脂质体转染法，将TNF-SP-EGFP融合基因转染COS-7细胞进行表达，经碘化丙啶（PI）染色后以激光共聚焦显微镜分析融合蛋白的表达及其亚细胞定位。结果PCR检测，酶切鉴定及测序证实目的基因TNF-SP正确连接到pEGFP-N1的多克隆位点。TNF-SP-EGFP重组体转染COS-7后，激光共聚焦显微镜显示TNF-SP-EGFP在细胞质表达。结论成功地构建了TNF-SP-EGFP融合蛋白真核表达质粒，在COS-7细胞中获得表达，并证实其定位于细胞质。

Construction of TNF-SP Expression Vector with EGFP and Its Expression and Localization in COS-7 Cell Lines

Objective To investigate the TNF-SP expression and its localization in mammalian cells.Methods TNF-SP gene was amplified with ploymerase chain reaction(PCR) from TNF-SP-pcDNA3.0 and was inserted into the eukaryotic expression vector pEGFP-N1.The recombinant plasmid TNF-SP-EGFP was identified with PCR,double enzyme digestion and DNA sequencing.The recombinant plasmid was transfected into COS-7 cell lines with lipofectamine.The transient expression and subcellular localization of the fusion proteins in the transfected COS-7 cells were analyzed by fluorescent microscopy and confocal microscopy.Results The recombinant plasmid TNF-SP-EGFP was confirmed with PCR,double enzyme digestion and DNA sequencing.The fluorescence microscopy revealed that the TNF-SP-EGFP fusion protein was expressed in COS-7 cells 24 h after transfection.Confocal microscopy showed that the TNF-SP-EGFP was distributed in cytoplasm.Conclusion The recombinant plasmid TNF-SP-EGFP was successfully constructed and expressed in COS-7 cells.The fusion protein was located in cytoplasm.