Role of Matrix and Fusion Proteins in Budding of Sendai Virus
AUTOR(ES)
Takimoto, Toru
FONTE
American Society for Microbiology
RESUMO
Paramyxoviruses are assembled at the surface of infected cells, where virions are formed by the process of budding. We investigated the roles of three Sendai virus (SV) membrane proteins in the production of virus-like particles. Expression of matrix (M) proteins from cDNA induced the budding and release of virus-like particles that contained M, as was previously observed with human parainfluenza virus type 1 (hPIV1). Expression of SV fusion (F) glycoprotein from cDNA caused the release of virus-like particles bearing surface F, although their release was less efficient than that of particles bearing M protein. Cells that expressed only hemagglutinin-neuraminidase (HN) released no HN-containing vesicles. Coexpression of M and F proteins enhanced the release of F protein by a factor greater than 4. The virus-like particles containing F and M were found in different density gradient fractions of the media of cells that coexpressed M and F, a finding that suggests that the two proteins formed separate vesicles and did not interact directly. Vesicles released by M or F proteins also contained cellular actin; therefore, actin may be involved in the budding process induced by viral M or F proteins. Deletion of C-terminal residues of M protein, which has a sequence similar to that of an actin-binding domain, significantly reduced release of the particles into medium. Site-directed mutagenesis of the cytoplasmic tail of F revealed two regions that affect the efficiency of budding: one domain comprising five consecutive amino acids conserved in SV and hPIV1 and one domain that is similar to the actin-binding domain required for budding induced by M protein. Our results indicate that both M and F proteins are able to drive the budding of SV and propose the possible role of actin in the budding process.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=114724Documentos Relacionados
- Interactions between the Transmembrane Segments of the Alphavirus E1 and E2 Proteins Play a Role in Virus Budding and Fusion
- Organ tropism of Sendai virus in mice: proteolytic activation of the fusion glycoprotein in mouse organs and budding site at the bronchial epithelium.
- Roles for the Cytoplasmic Tails of the Fusion and Hemagglutinin-Neuraminidase Proteins in Budding of the Paramyxovirus Simian Virus 5
- Assignment of disulfide bridges in the fusion glycoprotein of Sendai virus.
- Versatility of the Accessory C Proteins of Sendai Virus: Contribution to Virus Assembly as an Additional Role