Molecular Identification Of Common Carp JAK/STAT Genes And Their Expression Pattern

JAK-STAT pathway is the most important intracellular signaling pathways of numerous cytokines, growth factors and hormone molecule, involved in cell proliferation, differentiation, apoptosis and immune regulation, and other important biological processes. JAK is a kind of protein tyrosine kinase,it has been found that there are four members, namely JAK1-3and TyK2,they are not only catalytic linked to the receptor tyrosine phosphorylation residues, also can phosphorylate variety of signal molecules containing the Srv homologous region2(SH2domain). Signal transduction and transcriptional activation factor (STAT) is a kind of signaling molecules that contain Src homologous region2and can bind to the phosphorylated tyrosine Src homologous region2,they include STAT1, STAT2, STAT3, STAT4, STAT5a and STAT5b and STAT6, and contain four structure domain, such as SH2domain and DNA binding domains. STAT through its SH2domain structure bind to tyrosine phosphorylated cytokines receptor, and phosphorylate tyrosine residues of special C terminal by JAKs. STATs dissociate from the phosphorylated receptors, then form the homodimer or heterodimer by the SH2domain structure, then go into the nucleus, then impact the gene regulation of nuclear area, then regulate gene expression, at last accomplish cytokine signals transduction.This experiment cloned carp(Cyprinus carpio) STAT5, STAT6and TYK2gene sequence by adopted the RACE-PCR, analyzed of carp STAT5and STAT6and TYK2gene expression pattern of organization using real-time quantitative PCR, in order to clarify the carp JAK-STAT signaling pathway and its regulating function to lay the foundation.The results show that:the carp STAT5, STAT6and TYK2sequences full length are2494bp,2826bp and4959bp, respectively. Their lengths of the open reading frame (ORF) are2091bp,2310bp and3489bp respectively, and they inference encoding696aa,769aa and1162aa respectively. SMART and Scanprosite tool software for protein structure predicte the carp STAT5and STAT6have N terminal holomogy domain (NH2), Coiled-coil domain(CCD), DNA binding domain(DBD) and SH2domain, TYK2contains FERM structure domain, SH2domain, TyrKc domain-1and TyrKc domain-2. Through the multiple sequence alignment and phylogenetic tree building, carp STAT5, STAT6and TYK2corresponding sequence have the highest homology with zebrafish mostly respectively. Real-time quantitative PCR results shows that the STAT5, STAT6and TYK2mRNA expression have differences in different organizations.