Analysis of the cell fusion activities of chimeric simian immunodeficiency virus-murine leukemia virus envelope proteins: inhibitory effects of the R peptide.
AUTOR(ES)
Yang, C
RESUMO
It was previously reported that truncation or proteolytic removal of the C-terminal 16 amino acids (the R peptide) from the cytoplasmic tail of the murine leukemia virus (MuLV) envelope protein greatly increases its fusion activity. In this study, to investigate the specificity of the effect of the R peptide on the fusion activity of viral envelope proteins, we expressed simian immunodeficiency virus (SIV)-MuLV chimeric proteins in which the entire cytoplasmic tail of the SIV envelope protein was replaced by either the full-length MuLV cytoplasmic tail or a truncated MuLV cytoplasmic tail with the R peptide deleted. Extensive fusion of CD4-positive cells with the chimeric protein containing a truncated MuLV cytoplasmic tail was observed. In contrast, no cell fusion activity was found for the chimeric protein with a full-length MuLV cytoplasmic tail. We constructed another SIV-MuLV chimeric protein in which the MuLV R peptide was added to an SIV envelope protein cytoplasmic tail 17 amino acids from its membrane-spanning domain. No fusion activity was observed within this construct, while the corresponding truncated SIV envelope protein lacking the R peptide showed extensive fusion activity. No significant difference in the transport or surface expression was observed among the various SIV-MuLV chimeric proteins and the truncated SIV envelope protein. Our results thus demonstrate that the MuLV R peptide has profound inhibitory effects on virus-induced cell fusion, not only with MuLV but also in a distantly related retroviral envelope protein which utilizes a different receptor and fuses different cell types.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=189811Documentos Relacionados
- Mutations in the Cytoplasmic Tail of Murine Leukemia Virus Envelope Protein Suppress Fusion Inhibition by R Peptide
- Topography of murine leukemia virus envelope proteins: characterization of transmembrane components.
- Cell fusion induced by the murine leukemia virus envelope glycoprotein.
- Efficient pseudotyping of murine leukemia virus particles with chimeric human foamy virus envelope proteins.
- pH-independent murine leukemia virus ecotropic envelope-mediated cell fusion: implications for the role of the R peptide and p12E TM in viral entry.