Postbinding fusion function contributed by a chimeric murine leukemia virus envelope protein.
We previously obtained a chimeric Friend murine leukemia virus (FMLV) envelope protein (Env) in which the whole receptor-binding domain (RBD) was replaced with a surface domain of human CD4. Here, we examined if the postbinding fusion function of the CD4-Env chimera still remains to be intact. While a pseudotype MLV bearing CD4-Env showed no infectivity, NIH 3T3 cells could be infected with a pseudotype MLV bearing both CD4-Env and a mutant FMLV Env defective in postbinding fusion function. The pseudotype MLV showed no infectivity on HeLa cells but on the FMLV receptor (mCAT1)-expressing HeLa cells. In NIH 3T3 cells, the R-peptide-deleted CD4-Env could not induce syncytia by itself but did so in co-operation with the fusion-deficient Env. Syncytia induced by the coexpression were not observed in HeLa cells but in the mCAT1-expressing HeLa cells. These results indicate that the CD4-Env could contribute postbinding fusion function in the membrane fusion process triggered by FMLV RBD-mCAT1 interaction.
Nakamura
H
H
AIDS Research Center, National Institute of Infectious Diseases, Musashi-Murayama, Tokyo, Japan.
Takeda
A
A
Matano
T
T
D016475:3T3 Cells / Q000821:virology; D000818:Animals; D001665:Binding Sites; D015704:CD4 Antigens / Q000235:genetics*; D003588:Cytopathogenic Effect, Viral / Q000235:genetics; D005622:Friend murine leukemia virus / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D015686:Gene Products, env / Q000502:physiology*; D015752:Genes, env; D015726:Giant Cells / Q000821:virology; D006367:HeLa Cells / Q000821:virology; D006801:Humans; D008561:Membrane Fusion / Q000235:genetics / Q000502:physiology*; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D017354:Point Mutation; D017434:Protein Structure, Tertiary; D011991:Receptors, Virus / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000502:physiology*; D014774:Virulence; D014776:Virus Cultivation
D015704:CD4 Antigens; D015686:Gene Products, env; D008562:Membrane Glycoproteins; D011991:Receptors, Virus; D011993:Recombinant Fusion Proteins; C070506:ecotropic murine leukemia virus receptor