禽流感病毒血凝素基因突变体的构建及其在293T细胞中的表达

采用PCR定点突变技术,通过重叠延伸法3次PCR扩增,扩增片段上含有所需要的突变位点,最后将扩增片段克隆入pcDNA3载体中,DNA测序表明在预期位点已经发生突变,HA基因裂解位点的氨基酸组成为RKKR↓GLF突变为RSSR↓GLF,通过磷酸钙共沉淀方法将HA基因突变体的重组质粒瞬时转染293T细胞,采用间接免疫荧光鉴定其表达情况。IFA证实突变后的HA在细胞膜上获得了有效表达。HA基因突变体的成功构建,为进一步研究该突变位点导致AIV进入细胞的发病机制和HA蛋白的结构和功能的关系奠定了基础。

PCR site-directed mutagenesis of avian influenza virus hemagglutinin gene in vitro and expression in 293T cell

The site-directed mutagenesis of HA gene was made by using PCR, and mismatches were introduced into primers. Mutagenesis was performed in a three-step PCR. The amplified fragments from the second PCR which contained the mutation site were cloned into the pcDNA3 vector, named pHAm. The sequencing analysis showed that the mutation site was correct. The amino acid sequence at the cleavage site of the HA protein was from RKKR decrease GLF to RSSR decrease GLF. The recombinant plasmid pHAm was transiently transfected into 293T cells by the calcium phosphate precipitation method. Indirect immunofluorescent assay (IFA), confirmed expression of the HA protein on the cell membrane, the mutant HA gene was a promising candidate for further studies.