无脊椎动物innexin(inx)基因是生物进化上高度保守的基因,区别于脊椎动物的connexin。Inx基因可在细胞膜表面形成功能性的半通道蛋白hemichannel和间隙连接蛋白gap junction,这两种蛋白都与信号传导,胚胎发育,神经系统分化等功能相关。本研究在斜纹夜蛾Spodoptera litura血细胞转录组数据中发现特异的inx1,inx4序列,通过RT-PCR克隆出了Spli-inx1,Spli-inx4,经过比对,确定它们都属于保守的inx基因家族,具有四个保守的跨膜结构域,两个胞外环,一个胞内环,一个位于第二个跨膜结构域前端的YYQWV基序及在胞外环上各有2个半胱氨酸残基。其中,Spli-inx1开放阅读框全长1086 bp,编码361个氨基酸;Spli-inx4开放阅读框全长1116 bp,编码371个氨基酸。构建了包含ORF全长编码区的原核表达载体及真核表达载体,经Western blot证明Spli-inx1和Spli-inx4均可在大肠杆菌及鳞翅目昆虫High Five,Sf9和Spli221细胞系中的表达,初步探索了它们在细胞中的结构和功能。为深入研究Spli Inx1和Spli Inx4的功能奠定基础。
Innexin( inx) is a highly conserved gene in the invertebrate,different from the connexin of the vertebrate. Inxs could form functional proteins( hemichannels and gap junctions) on the cell surface,both relate to the cell signaling pathway,embryonic development and nervous system differentiation. In this study,we cloned inx1 and inx4 Open Reading Frame( ORF) from the Spodoptera litura hemocytes.Then we demonstrated inx1 and inx4 belongs to the conversed inx gene family with sequencing and alignment,named Spli-inx1 and Spli-inx4. They all have four transmembrane domains,two extracellular loops,one intracellular loop,a YYQWV motif and two cysteine residues on the extracellular loops. Spliinx1 is 1086 bp in length,encoding a 361 amino acids,Spli-inx4 is 1116 bp and encoding a 371 amino acids. Finally,we constructed expression vectors for prokaryotic and eukaryotic system,demonstrated Spli Inx1 and Spli Inx4 expressed in E. coli and lepidopteran insect cell lines,High Five,Sf9 and Spli221,with western blot. This study lays the foundation for the further functional study of inx1 and Inx4 in S. litura.