An interaction between the nucleocapsid protein and a component of the replicase-transcriptase complex is crucial for the infectivity of coronavirus genomic RNA.
J Virol
; 84(19): 10276-88, 2010 Oct.
Article
en En
| MEDLINE
| ID: mdl-20660183
ABSTRACT
The coronavirus nucleocapsid (N) protein plays an essential role in virion assembly via interactions with the large, positive-strand RNA viral genome and the carboxy-terminal endodomain of the membrane protein (M). To learn about the functions of N protein domains in the coronavirus mouse hepatitis virus (MHV), we replaced the MHV N gene with its counterpart from the closely related bovine coronavirus (BCoV). The resulting viral mutant was severely defective, even though individual domains of the N protein responsible for N-RNA, N-M, or N-N interactions were completely interchangeable between BCoV and MHV. The lesion in the BCoV N substitution mutant could be compensated for by reverting mutations in the central, serine- and arginine-rich (SR) domain of the N protein. Surprisingly, a second class of reverting mutations were mapped to the amino terminus of a replicase subunit, nonstructural protein 3 (nsp3). A similarly defective MHV N mutant bearing an insertion of the SR region from the severe acute respiratory syndrome coronavirus N protein was rescued by the same two classes of reverting mutations. Our genetic results were corroborated by the demonstration that the expressed amino-terminal segment of nsp3 bound selectively to N protein from infected cells, and this interaction was RNA independent. Moreover, we found a direct correlation between the N-nsp3 interaction and the ability of N protein to stimulate the infectivity of transfected MHV genomic RNA (gRNA). Our results suggest a role for this previously unknown N-nsp3 interaction in the localization of genomic RNA to the replicase complex at an early stage of infection.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
ARN Polimerasas Dirigidas por ADN
/
ARN Polimerasa Dependiente del ARN
/
ARN Viral
/
Coronavirus Bovino
/
Virus de la Hepatitis Murina
/
Proteínas de la Nucleocápside
Límite:
Animals
/
Humans
Idioma:
En
Revista:
J Virol
Año:
2010
Tipo del documento:
Article
País de afiliación:
Estados Unidos