Point mutations in Moloney murine leukemia virus envelope protein: effects on infectivity, virion association, and superinfection resistance.
Retroviral envelope proteins are synthesized in the infected cell and targetted to the assembling virion; during infection, they mediate receptor binding and fusion of the virion and cell membranes. We have generated a series of mutants of the Moloney murine leukemia virus (M-MuLV) with alterations in the TM protein, p15E, and determined whether the mutants are defective for replication and where the defects lie. Twenty-one point mutants were assessed for infectivity, virion-associated envelope protein levels, and the ability to confer resistance to superinfection. Only one mutant was specifically defective in a post-receptor binding step. Three other mutants encoded virion-associated envelope proteins that could not confer resistance to superinfection, implying that they could not bind to the receptor. These mutants demonstrate that in M-MuLV, receptor binding and early events such as membrane fusion can be affected by amino acid changes in the TM protein.
Berkowitz
R D
RD
Howard Hughes Medical Institute, Columbia University College of Physicians and Surgeons, New York, New York 10032.
Goff
S P
SP
D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D015686:Gene Products, env / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D008979:Moloney murine leukemia virus / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity; D017354:Point Mutation; D011991:Receptors, Virus / Q000378:metabolism; D015163:Superinfection / Q000235:genetics; D014162:Transfection; D014771:Virion / Q000254:growth & development; D014774:Virulence
D015686:Gene Products, env; D011991:Receptors, Virus