目的:通过构建PAX3基因及其突变体表达质粒初步研究其外源性表达和定位表达,为研究Waar-denburg综合征(Waardenburg syndrome ,WS)发病机制提供实验基础。方法通过分子克隆技术双酶切pECE -PAX3和pcDNA3.0-HA后连接构建PAX3基因重组真核细胞表达质粒pcDNA3.0-PAX3-HA ,以其为模板分别构建PAX3基因新发突变H80D和H186fs表达质粒pcDNA3.0-H80D-HA和pcDNA3.0-H186fs-HA , DNA测序鉴定。将PAX3、H80D和H186fs表达质粒分别瞬时转染小鼠胚胎成纤维细胞(NIH3T3细胞),采用Western blot和细胞免疫荧光法分别检测和观察野生PAX3蛋白和突变 H80D、H186fs蛋白在NIH3T3细胞中的表达和分布。结果 PAX3及其突变体 H80D和H186fs表达质粒经DNA测序鉴定序列正确,三者在NIH3T3细胞中正确表达,H80D与PAX3仅在细胞核中分布,H186fs在细胞质与细胞核中均有分布。结论本研究成功构建了PAX3基因及其突变体真核细胞表达质粒,突变对PAX3蛋白的亚细胞定位产生影响,为在体外实验进一步研究国人PAX3基因突变致WS发病的分子机制奠定了实验基础。
Objective To study exogenous expression and subcellular localization of wild type (WT ) and mu-tant PAX3 proteins in vitro by generating their expression plasmids for further study of pathogenesis of Waarden-burg syndrome (WS) .Methods The plasmids pECE-PAX3 and pcDNA3 .0-HA were ligased after they were cut by double enzyme digestion using molecular cloning technique to generate recombinant eukaryotic expression plasmid pcDNA3 .0-PAX3-HA ,which was as a template to generate expression plasmids pcDNA 3 .0 -H80D -HA and pcDNA3 .0-H186fs-HA of novel mutations H80D and H186fs of PAX3 gene .All constructs were verified by di-rect nucleotide sequencing .NIH3T3 cells were transfected transiently with the expression plasmids of PAX3 ,H80D and H186fs respectively .The exogenous expression of WT PAX3 protein and mutant H80D ,H186fs proteins were analysed using Western blot assay ,while their subcellular distribution were observed using immunofluorescence as-say .Results The DNA sequences of expression plasmids of PAX3 and its mutant H80D ,H186fs were correct . Both WT and mutant PAX3 proteins were detected at the expected size .WT PAX3 and H80D proteins were only lo-calized in the nucleus ,whereas H186fs protein showed aberrant localization in both cytoplasm and nucleus .Conclu-sion We successfully generated the recombinant eukaryotic expression plasmids of PAX 3 gene and its mutants and drew preliminary conlusion of gene mutation having effect on subcellular distribution of WT PAX 3 proteins in vitro , which lays experimental basis for further study of the moceluar mechanism of WS caused by PAX3 gene mutations in China .