马岗鹅TLR3基因选择性剪切体的克隆及生物信息学分析

Cloning and Bioinformational Analysis of Alternative Splicing Variant of TLR3 in Goose

为了研究鹅Toll样受体3(gTLR3)基因选择性剪切体在抗感染免疫中的作用,根据鸡、人和小鼠TLR3基因序列设计引物,利用RT-PCR和SMART RACE技术,首次克隆了鹅TLR3基因的选择性剪切体。所得基因序列提交GeneBank,登录号:KC292271。结果表明:核酸序列分析表明,鹅TLR3基因选择性剪切体开放阅读框长2283 bp,编码761个氨基酸,该蛋白等电点7.56,分子量为86.29 kD;与鹅、鸡、小鼠、猪、鱼、牛、羊和人的同源性分别为84.71%、74.40%、48.63%、50.38%、40.09%、50.16%、50.71%和50.98%。推导的氨基酸序列分析显示,在其胞外具有LRRs结构域,跨膜区和不完整的TIR结构域,N末端存在信号肽,且可能在26～27位氨基酸处存在裂解位点。胞外区有14个明显的LRR和15个N连接的糖基化位点。文章首次证实鹅TLR3选择性剪切体的存在,为进一步研究该基因的功能和蛋白质的特性奠定了基础。

The objective of the present study was to investigate the role of alternative splicing variant of toll like receptor 3 （gTLR3-ASV） in anti-infections immunity in goose. The primers were designed according to TLR3 gene sequence in goose, chicken, human and mouse. Using RT-PCR and SMART RACE techniques, TLR3-A SV was cloned from spleen tissue in Magang geese successfully. The results showed that gTLR3-ASV gene consisted of 2 283 base pairs （gi： KC292271 ）and coding 761 amino acids. The molecular weight and the isoelectric point of gTLR3-ASV putative protein was 86.29 kD and 7.56, respectively, and had a transmembrane region （696-718） and a signal peptide, gTLR3-A VS gene sequence had high homology compared with TLR3 in goose （84.71% ）, chicken （74.4%）, mice （48.63%）, fish （40.09%）, cattle （50.16%）, sheep （50.71% ） and human （50.98%）. The sequence analysis of deduced amino acids indicated that it contained a LRRs ectodomain, a transmembrane region and incomplete TIR domains in its extracellular. There were fourteen leucine-rich repeats and fifteen N-linked glycosylation sites located in extra-membrane. In our knowledge, the present study found an alternative splicing variant in TLR3 of goose firstly, and constructed a base for further elucidating the structure and function of TLR3 in goose.