Functional genomic studies on an immune-and antiviral-related gene of MyD88 in orange-spotted grouper,Epinephelus coioides

• 来源期刊: 科学通报(英文版)
• 学科: 农学
• 年，卷（期）: 2012,（25）
• 页码范围: 3278-3288
• 页数: 11页
• 分类号: S943
• 语种: 中文

摘要

Myeloid differentiation factor 88(MyD88) is a universal adaptor protein involved in Toll-like receptors and in interleukin-1 receptor-induced nuclear factor-kappaB(NF-κB) activation.In this study,a new MyD88 gene(designated as Og-MyD88) was cloned from orange-spotted grouper,Epinephelus coioides,based on the expressed sequence tag(EST) obtained following Roche 454 GS-FLX sequencing.The full-length Og-MyD88 cDNA is composed of 1682 bp and encodes a deduced polypeptide of 289 amino acids with 86% homology to MyD88 of Siniperca chuatsi.The deduced amino acid sequence of Og-MyD88 contains a typical death domain at the amino terminus and a conserved Toll/IL-1R(TIR) domain at the carboxyl terminus,as well as three highly conserved motifs(Box1,Box2 and Box3) within the C-terminal TIR domain.In healthy fish,Og-MyD88 was found to be strongly expressed in immune-related tissues,including the spleen,head kidney,kidney,liver,skin and intestine,with lower expression in heart,stomach,brain and muscle.Transcripts of Og-MyD88 were found to be markedly up-regulated in fish spleen after challenge with Singapore grouper iridovirus(SGIV),a highly lethal viral pathogen to grouper fish.Furthermore,the full length Og-MyD88 and its N-terminal death domain were capable of inducing NF-κB activity in HEK-293 cells.Overexpressed Og-MyD88 showed the ability to inhibit replication of SGIV in grouper spleen(GS) cells.These results suggest that Og-MyD88 is involved in the grouper immune response to invasion of viral pathogens and may share similar functions to those observed in higher vertebrates.