title: Characterization of the VP39 envelope protein from Singapore grouper iridovirus.
abstract: Singapore grouper iridovirus (SGIV) is a major pathogen that causes heavy economic losses to the grouper aquaculture industry in China and Southeast Asian countries. In the present study, a viral envelope protein, VP39, encoded by SGIV ORF39L, was identified and characterized. SGIV ORF39L was found in all sequenced iridoviruses and is now considered to be a core gene of the family Iridoviridae. ORF39L was classified as a late gene during in vitro infection using reverse transcription-polymerase chain reaction, western blotting, and a drug inhibition analysis. An indirect immunofluorescence assay revealed that the VP39 protein was confined to the cytoplasm, especially at viral assembly sites. Western blot and matrix-assisted laser desorption/ionization-time of flight tandem mass spectrometry analyses suggested that VP39 is an envelope protein. Immunogold electron microscopy further confirmed that VP39 is a viral envelope protein. Furthermore, a mouse anti-VP39 polyclonal antibody exhibited SGIV-neutralizing activity in vitro, suggesting that VP39 is involved in SGIV infection. Taken together, the current data suggest that VP39 represents a conserved envelope protein of iridoviruses that contributes to viral infection.
authors.affiliation: a State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 West Xingang Road, Guangzhou 510275, People's Republic of China.|c College of Fishery, Guangdong Ocean University, Zhanjiang 524088, Guangdong, People's Republic of China.
authors.forename: Honglian
authors.initials: H
authors.lastname: Zhang
authors.affiliation: b Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, People's Republic of China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Zhou
authors.affiliation: c College of Fishery, Guangdong Ocean University, Zhanjiang 524088, Guangdong, People's Republic of China.
authors.forename: Liqun
authors.initials: L
authors.lastname: Xia
authors.affiliation: b Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, People's Republic of China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Huang
authors.affiliation: b Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, People's Republic of China.
authors.forename: Youhua
authors.initials: Y
authors.lastname: Huang
authors.affiliation: a State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 West Xingang Road, Guangzhou 510275, People's Republic of China.
authors.forename: Jianhao
authors.initials: J
authors.lastname: Cao
authors.affiliation: b Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, People's Republic of China.
authors.forename: Qiwei
authors.initials: Q
authors.lastname: Qin
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002681:China; D005393:Fish Diseases / Q000821:virology*; D051379:Mice; D008969:Molecular Sequence Data; D010473:Perciformes / Q000821:virology; D010802:Phylogeny; D012328:RNA Viruses / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D012846:Singapore; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014759:Viral Envelope Proteins / Q000235:genetics
chemical_list: D014759:Viral Envelope Proteins
keywords: Singapore grouper iridovirus (SGIV); VP39; envelope protein; gène tardif; iridovirus du mérou de Singapour (SGIV); late gene; protéine de l’enveloppe