VP5 autocleavage is required for efficient infection by in vitro-recoated aquareovirus particles.
Grass carp reovirus (GCRV) is a member of the genus Aquareovirus in the family Reoviridae, and contains five core proteins (VP1-VP4 and VP6) and two outer-capsid proteins (VP5 and VP7) in its particle. Previous studies have revealed that the outer-capsid proteins of reovirus are responsible for initiating infection, but the mechanism is poorly understood. Using baculovirus-expressed VP5 and VP7 to recoat purified cores, in vitro assembly of GCRV was achieved in this study. Recoated GCRV (R-GCRV) closely resembled native GCRV (N-GCRV) in particle morphology, protein composition and infectivity. Similar to N-GCRV, the infectivity of R-GCRV could be inhibited by treating cells with the weak base NH4Cl. In addition, recoated particles carrying an Asn→Ala substitution at residue 42 of VP5 (VP5N42A/VP7 R-GCRV) were no longer infectious. These results provide strong evidence that autocleavage of VP5 is critical for aquareovirus to initiate efficient infection.
1State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China 2University of Chinese Academy of Sciences, Beijing, PR China.
Shicui
S
Yan
1State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China.
Jie
J
Zhang
1State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China.
Hong
H
Guo
1State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China 2University of Chinese Academy of Sciences, Beijing, PR China.
Liming
L
Yan
1State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China 2University of Chinese Academy of Sciences, Beijing, PR China.
Qingxiu
Q
Chen
1State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China.
Fuxian
F
Zhang
1State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China.
Qin
Q
Fang
D000818:Animals; D016367:Baculoviridae / Q000235:genetics; D005399:Fishes; D005822:Genetic Vectors; D059748:Proteolysis; D012087:Reoviridae / Q000235:genetics / Q000502:physiology*; D015678:Viral Structural Proteins / Q000378:metabolism*; D019065:Virus Assembly; D053586:Virus Internalization; D014779:Virus Replication
D015678:Viral Structural Proteins