M-X-I motif of semliki forest virus capsid protein affects nucleocapsid assembly.
J Virol
; 75(10): 4625-32, 2001 May.
Article
em En
| MEDLINE
| ID: mdl-11312332
ABSTRACT
Alphavirus budding is driven by interactions between spike and nucleocapsid proteins at the plasma membrane. The binding motif, Y-X-L, on the spike protein E2 and the corresponding hydrophobic cavity on the capsid protein were described earlier. The spike-binding cavity has also been suggested to bind an internal hydrophobic motif, M113-X-I115, of the capsid protein. In this study we found that replacement of amino acids M113 and I115 with alanines, as single or double mutations, abolished formation of intracellular nucleocapsids. The mutants could still bud efficiently, but the NCs in the released virions were not stable after removal of the membrane and spike protein layer. In addition to wild-type spherical particles, elongated multicored particles were found at the plasma membrane and released from the host cell. We conclude that the internal capsid motif has a biological function in the viral life cycle, especially in assembly of nucleocapsids. We also provide further evidence that alphaviruses may assemble and bud from the plasma membrane in the absence of preformed nucleocapsids.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vírus da Floresta de Semliki
/
Capsídeo
/
Montagem de Vírus
/
Nucleocapsídeo
Limite:
Animals
Idioma:
En
Revista:
J Virol
Ano de publicação:
2001
Tipo de documento:
Article