Structural and functional genomics study of Singapore grouper iridovirus

Abstract

We have investigated the host and Singapore grouper iridovirus (SGIV) proteomes upon virus infection using the isobaric Tags for Relative and Absolute Quantification (iTRAQ) method. A large number of host proteins and novel viral proteins were identified and quantitated in non-infected and infected Grouper embryonic cells. In addition, gene knock-down platform using morpholino antisense oligonucleotides (MO) was successfully set up in our lab. In this project, ORF018R, ORF140L and ORF135L were specifically and efficiently knocked down using specific MO. We also examined the effects of knock-downs on virus infectivity and virion particle assembly.. The data reveals the relationship between specific knock-downs of viral ORFs with several host proteins which might be involved in virus entry and infection. ORF102L which encodes SGIV ubiquitin-like (UBL) protein was selected for further studies. The purified recombinant SGIV UBL was shown to be functional in the ubiquitination assay. The structure of SGIV UBL was determined using NMR.