ULBP3胞外段基因的克隆与表达

目的 为了研究ULBP3刺激NK细胞增殖分化的功能，首先需构建、表达ULBP3胞外段重组蛋白。方法 用RT-PCR方法从人结肠癌组织中钓取ULBP3胞外段基因，构建pET32a原核表达载体，转化大肠杆菌BL21，以IPTG诱导表达，Western blot鉴定。结果 经测序证实，所获得的cDNA克隆为ULBP3胞外段基因，其序列与genebank中已经发表的序列完全一致，pET32a原核表达载体转化大肠杆菌BL21后，经筛选获得的阳性重组菌稳定表达ULBP3胞外段重组蛋白。结论 成功表达了ULBP3胞外段重组蛋白，可用于进一步研究ULBP3刺激NK细胞增殖分化的功能。

Cloning and expression of extracellular domain of ULBP3

Objective To study the effect of ULBP3 on NK cell proliferation and activation, we manage to obtain the extracellular domain of ULBP3 protein at first. Methods The extracellular domain of ULBP3 gene fragment was isolated by RT-PCR from human osteosarcoma cell line Saos-2. After sequencing identification, it was cloned into the pET32a prokaryotic expression vector, and then the recombinant plasmid was transduced into E.Coli. BL21, target protein expression was induced by IPTG.Results The sequencing result showed that the nucleotide sequence of the DNA fragment obtained was totally identical with ULBP3 extracellular domain in GeneBank. The recombinant pET32a plasmid was constructed successfully and the extracellular domain of ULBP3 protein was expressed stably in the recombinant bacteria.Conclusion The extracellular domain of ULBP3 protein obtained can be used for further research.