title: Virion-associated viral proteins of a Chinese giant salamander (Andrias davidianus) iridovirus (genus Ranavirus) and functional study of the major capsid protein (MCP).
abstract: Chinese giant salamander iridovirus (CGSIV) is the emerging causative agent to farmed Chinese giant salamanders in nationwide China. CGSIV is a member of the common midwife toad ranavirus (CMTV) subset of the amphibian-like ranavirus (ALRV) in the genus Ranavirus of Iridoviridae family. However, viral protein information on ALRV is lacking. In this first proteomic analysis of ALRV, 40 CGSIV viral proteins were detected from purified virus particles by liquid chromatography-tandem mass spectrometry analysis. The transcription products of all 40 identified virion proteins were confirmed by reverse transcription polymerase chain reaction analysis. Temporal expression pattern analysis combined with drug inhibition assay indicated that 37 transcripts of the 40 virion protein genes could be classified into three temporal kinetic classes, namely, 5 immediate early, 12 delayed early, and 20 late genes. The presence of major capsid proteins (MCP, ORF019L) and a proliferating cell nuclear antigen (ORF025L) was further confirmed by Western blot analysis. The functions of MCP were also determined by small interfering RNA (siRNA)-based knockdown assay and anti-recombinant MCP serum-based neutralization testing. At low dosages of CGSIV, siRNA-based knockdown of the MCP gene effectively inhibited CGSIV replication in fathead minnow cells. The antiviral effect observed in the anti-MCP serum-based neutralization test confirms the crucial function of the MCP gene in CGSIV replication. Taken together, detailed information on the virion-associated viral proteins of ALRV is presented for the first time. Our results also provide evidence that MCP is essential for CGSIV replication in vitro.
authors.affiliation: State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Biology, Jinan University, Guangzhou 510632, PR China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China.
authors.forename: Shaoping
authors.initials: S
authors.lastname: Weng
authors.affiliation: Department of Biology, Jinan University, Guangzhou 510632, PR China.
authors.forename: Gaoxiang
authors.initials: G
authors.lastname: Zhao
authors.affiliation: State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China; School of Marine Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China.
authors.forename: Jianguo
authors.initials: J
authors.lastname: He
authors.affiliation: State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China. Electronic address: dongchfu@mail.sysu.edu.cn.
authors.forename: Chuanfu
authors.initials: C
authors.lastname: Dong
mesh_terms: D000818:Animals; D036022:Capsid Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D002681:China; D004266:DNA Virus Infections / Q000662:veterinary* / Q000821:virology; D015967:Gene Expression Regulation, Viral; D007497:Iridoviridae / Q000145:classification / Q000235:genetics*; D009500:Neutralization Tests; D020543:Proteome / Q000235:genetics* / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D014158:Transcription, Genetic; D014562:Caudata / Q000821:virology*; D014771:Virion / Q000235:genetics* / Q000378:metabolism; D014779:Virus Replication
chemical_list: D036022:Capsid Proteins; D020543:Proteome; D034741:RNA, Small Interfering
keywords: Chinese giant salamander iridovirus; Major capsid protein (MCP); Neutralization test; Proteomics; Virion protein; siRNA