Identification and characterization of a novel capsid protein encoded by Singapore grouper iridovirus ORF038L.
Singapore grouper iridovirus (SGIV) is an important pathogen isolated from grouper, Epinephelus tauvina, and characterized as a novel ranavirus. To better understand the function of viral structural genes involved in SGIV infection and virus-host interactions, a candidate gene, VP38 (ORF038L), was investigated in this study. SGIV VP38 was found to encode a 170-aa peptide containing an RGD motif, and it showed significant identity only to members of the genus Iridovirus, family Iridoviridae, except megalocytivirus. The VP38 gene was identified by temporal expression pattern analysis and drug inhibition assay as a late (L) gene. Immunofluorescence localization revealed that P38 was distributed predominately in the cytoplasm and that association of VP38 with viral factories increased at the late stage of SGIV infection. Consistent results from immunoelectron microscopy (IEM) and western blot analysis revealed that SGIV VP38 is a viral capsid protein. Furthermore, antibodies specific for SGIV VP38 exhibited substantial SGIV-neutralizing activity in vitro, suggesting that VP38 might play an important role in SGIV infectivity.
State Key Laboratory of Biocontrol, School of Life Science, Sun Yat-sen University, 135 West Xingang Road, Guangzhou, China.
Qing Jiao
QJ
Wan
Jie
J
Gong
Xiao Hong
XH
Huang
You Hua
YH
Huang
Sheng
S
Zhou
Zheng Liang
ZL
Ou-Yang
Jian Hao
JH
Cao
Li Li
LL
Ye
Qi Wei
QW
Qin
D000595:Amino Acid Sequence; D000818:Animals; D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral / Q000276:immunology; D001492:Bass / Q000821:virology; D015153:Blotting, Western; D036022:Capsid Proteins / Q000235:genetics*; D003593:Cytoplasm / Q000737:chemistry; D020869:Gene Expression Profiling; D017994:Iridovirus / Q000235:genetics; D008856:Microscopy, Fluorescence; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D016366:Open Reading Frames; D010802:Phylogeny; D020543:Proteome / Q000032:analysis; D017995:Ranavirus / Q000235:genetics* / Q000302:isolation & purification; D017386:Sequence Homology, Amino Acid; D014771:Virion / Q000737:chemistry / Q000648:ultrastructure
D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D036022:Capsid Proteins; D020543:Proteome