肿瘤及胚胎特异表达蛋白CEP65的真核细胞表达及其细胞定位

Eukaryotic Expression and Intracellular Distribution of Cancer and Embryo Expression Protein 65

背景与目的:既往研究表明,肿瘤相关抗原CEP65(cancer and em bryoexpression protein65)仅表达于肿瘤和胚胎组织,本研究拟揭示CEP65在细胞中的分布,为进一步阐明CEP65在肿瘤发生、发展中的功能奠定基础。方法:构建肿瘤及胚胎特异表达基因Cep65与GST融合表达的真核表达质粒,通过DEAE-Dextran方法转染COS7细胞,分离细胞的胞浆蛋白和核蛋白,W estern blot检测CEP65在细胞中的分布情况。构建Cep65与红色荧光蛋白基因融合表达的真核表达质粒,转染细胞后,利用荧光显微镜观察CEP65在细胞中的分布。结果:通过细胞组分生化分析分离细胞胞浆蛋白和核蛋白,W estern blot检测结果表明,表达的CEP65分布在细胞浆和细胞核中。荧光蛋白定位进一步分析发现,转染单纯荧光蛋白表达质粒的细胞,其荧光在细胞内呈弥散性分布,而转染CEP65与荧光蛋白基因融合表达质粒的细胞,在细胞质及细胞核内形成聚集的荧光颗粒。结论:CEP65可在COS7细胞中高效表达,其表达产物存在于细胞质和细胞核内;CEP65可能是一种核相关蛋白。

BACKGROUND & OBJECTIVE: Previous studies show that cancer and embryo expression protein 65 (CEP65) only expresses in various cancer cells and embryo cells. This study was to detect intracellular distribution of CEP65, and make the foundation for further CEP65 function study. METHODS: Two kinds of eukaryotic expression plasmids, which can separately express full-length CEP65-GST and fluorescent fusion protein CEP65-Red, were constructed, and transfected into COS7 cells by DEAE-Dextran method. Plasmosin and nucleoprotein of COS7 cells were separated. Intracellular distribution of CEP65 was detected by Western blot, and observed under fluorescent microscope. RESULTS: Western blot confirmed that CEP65 distributed in cytoplasm and nulei. Fluorescent protein localization showed diffuse distribution of fluorescence in the cells transfected with pcDNA3-Red, and collective fluorescent articles in cytoplasm and nuclei of the cells transfected with pcDNA3-Red-Cep65. CONCLUSIONS: CEP65 can express efficiently in COS7 cells, and locates in cytoplasm and nuclei. It may be a kind of nucleus-associated protein.