| 作者： |
Pang, An Ning; Chen, Shan Nan; Gan, Zhen; Li, Li; Li, Nan; Wang, Shuai; Sun, Zheng; Liu, Lan Hao; Sun, Yan Ling; Song, Xiao Jun; Liu, Yang; Wang, Su; Nie, P. |
| 论文摘要： |
In mammals, type II interferon (IFN; i.e. IFN-gamma) signalling transduces through its specific receptors IFN-gamma R1 and IFN-gamma R2. In an osteoglossiform fish, the arapaima Arapaima gigas, three type II IFNs, IFN-gamma-like, IFN-gamma and IFN-gamma rel, and their four possible receptor subunits IFN-gamma R1-1, IFN-gamma R1-2, IFN-gamma R2-1 and IFN-gamma R2-2 were identified in this study. The three type II IFN genes are composed of four exons and three introns, and they all contain IFN-gamma signature motif and signal peptide, with the presence of potential nuclear localization signal (NLS) in IFN-gamma-like and IFN-gamma. The IFN-gamma R1-1, IFN-gamma R1-2, IFN-gamma R2-1 and IFN-gamma R2-2 are composed of seven exons and six introns, with predicted IFN-gamma R1-1 and IFN-gamma R1-2 proteins containing JAK1 and STAT1 binding sites, and IFN-gamma R2-1 and IFN-gamma R2-2 containing JAK2 binding sites. Gene synteny analysis showed that the type II IFN and their receptor loci are duplicated in arapaima. All these genes were expressed constitutively in all organs/tissues examined, and responded to the stimulation of polyI:C. The prokaryotic recombinant IFN-gamma-like, IFN-gamma and IFN-gamma rel proteins can significantly induce the upregulation of immune-related genes in trunk kidney leucocytes. The ligand-receptor relationship analyses revealed that recombinant IFN-gamma-like, IFN-gamma, and IFN-gamma rel transduce downstream signal-ling through IFN-gamma R1-1/IFN-gamma R2-1, IFN-gamma R1-2/IFN-gamma R2-2, and IFN-gamma R1-1, respectively, in xenogeneic cells with the overexpression of original or chimeric receptors. In addition, tyrosine (Y) 366 and Y377 in the intracellular region may be essential for the function of IFN-gamma R1-2 and IFN-gamma R1-1, respectively. The finding of type II IFN system in A. gigas thus provides different knowledge in understanding the diversity and evolution of type II IFN ligand-receptor relationships in vertebrates. |
