荧光蛋白标签对gD囊膜蛋白在BHK-21细胞亚细胞定位的影响

Impact of fluorescent protein tag on gD envelope protein subcellular localization in BHK-21 cells

摘要:

[目的] 探究荧光蛋白标签对马疱疹病毒I型(Equine herpes virus type 1, EHV-1) gD囊膜蛋白亚细胞定位的影响。[方法] 以EHV-1基因组为模板利用PCR扩增gD全基因,分别克隆至pAcGFP1-C1和pDsRed2-N1质粒,构建pAc-GFP-gD (GFP-gD)和pDs-gD-Red (gD-Red)重组质粒;将GFP基因插入gD基因信号肽序列之后并克隆至PVAX-1质粒,构建PVAX-S-GFP-gD' (S-GFP-gD')重组质粒;将Flag标签序列与gD囊膜蛋白N端序列融合后并克隆至pVAX-1表达载体,构建pVAX-Flag-gD (Flag-gD)重组质粒。将4种不同重组真核表达质粒分别转染BHK-21细胞,通过激光共聚焦显微镜对不同融合蛋白gD进行亚细胞定位。[结果] 成功构建4种不同的融合蛋白gD真核表达载体;在BHK-21细胞单独表达时,不同融合蛋白gD绝大部分都定位于高尔基体,极少量定位于细胞核内。[结论] 不同插入位点的荧光蛋白标签对gD囊膜蛋白亚细胞定位无明显影响,这对今后研究其它蛋白亚细胞定位提供参考。

Abstract:

[Objective] The fluorescent protein and gD envelope protein of equine herpes virus type 1 (EHV-1) were used to study the impact of tags on gD protein subcellular localization in BHK-21 cells. [Methods] With the EHV-1 genome as a template, the gD complete gene was amplified by PCR technique. The product of PCR was cloned to pAcGFP1-C1 and pDsRed2-N1 plasmids. The recombinant plasmids were designated as pAc-GFP-gD (GFP-gD) and pDs-gD-Red (gD-Red). The GFP gene was inserted into the posterior position of gD gene signal peptide sequence. The modified gD gene signal peptide sequence was cloned to pVAX-1 plasmid, so that pVAX-S-GFP-gD' (S-GFPgD') recombinant plasmid was constructed. Meanwhile, the flag tag was added to N-terminal of gD sequence and they were cloned to pVAX-1 expression vector for constructing pVAX-Flag-gD recombinant plasmid. The BHK-21 cells were transfected with the 4 different recombinant plasmids and the subcellular localizations of fusion proteins were determined by lasar confocal scan microscopy. [Results] Four eukaryotic expression vectors were constructed successfully. In BHK-21 cells, the vast majority of gD envelope proteins was localized in Golgi, and a small amount of gD was localized in the nucleus. [Conclusion] Our finding reveals that the fluorescent protein of different insertion sites has no significant effects on the subcellular localization of gD, and provides a useful reference for other researchers.