Functional genomic study of Singapore Grouper Iridovirus

Abstract

Iridovirus is a pathogen causing serious systemic diseases among feral, cultured and ornamental fish. Our lab aims to explore iridovirus infection mechanism and anti-iridovirus drug discovery. A knockdown platform has been built up for an effective knockdown of certain genes from SGIV. With phenotype screening a functional important SGIV encoded protein - ORF018R was successfully identified. Knockdown of ORF018R expression resulted in reduction of expression of viral late genes, distortion of viral particle assembly and inhibition of SGIV infection in grouper embryonic cells. Immunoblot and 2DE-MS showed five enhanced phosphorylated proteins including three viral proteins and two host proteins. Moreover, One SGIV encoded kinase-ORF039L was identified and another viral protein ORF075R could be phosphorylated by ORF039L in vitro. Thus ORF018R was probably a kinase inhibitory protein in SGIV infected cells. Based on this study, the mechanism of SGIV infection was explored which would facilitate anti-iridovirus research.