       Document 0199
 DOCN  M9440199
 TI    Cysteine residues in the Vif protein of human immunodeficiency virus
       type 1 are essential for viral infectivity.
 DT    9404
 AU    Ma XY; Sova P; Chao W; Volsky DJ; Molecular Virology Laboratory, St.
       Luke's/Roosevelt Hospital; Center, New York, New York 10019.
 SO    J Virol. 1994 Mar;68(3):1714-20. Unique Identifier : AIDSLINE
       MED/94149864
 AB    The infectivity factor of human immunodeficiency virus type 1 (HIV-1),
       Vif, contains two cysteine residues which are highly conserved among
       animal lentiviruses. We introduced substitutions of leucine for cysteine
       residues in the vif gene of a full-length HIV-1 clone to analyze their
       roles in viral infection. Mutant viruses containing substitutions in
       either Cys-114, Cys-133, or both displayed a vif-negative infection
       phenotype similar to that of an isogeneic vif deletion mutant, namely, a
       cell-dependent complete to partial loss of infectivity. The vif defect
       could be complemented by cotransfection of mutant viral DNA with a Vif
       expression vector, and there was no evidence that recombination
       contributed to the repair of the vif deficiency. The viral protein
       profile, as determined by immunoblotting, in cells infected with
       cysteine substitution mutants and that in wild-type virus were similar,
       including the presence of the 23-kDa Vif polypeptide. In addition,
       immunoblotting with an antiserum directed against the carboxyl terminus
       of gp41 revealed that gp41 was intact in cells infected with either
       wild-type or vif mutant HIV-1, excluding that Vif cleaves the C terminus
       of gp41. Our results indicate that the cysteines in HIV-1 Vif are
       critical for Vif function in viral infectivity.
 DE    Amino Acid Sequence  Base Sequence  Comparative Study
       *Cysteine/GENETICS  Gene Products, vif/BIOSYNTHESIS/*GENETICS  Genetic
       Complementation Test  Human  HIV Core Protein p24/BIOSYNTHESIS  HIV
       Envelope Protein gp41/METABOLISM  HIV-1/GENETICS/*PATHOGENICITY
       Molecular Sequence Data  Mutation  Protein Processing,
       Post-Translational  Sequence Homology, Nucleic Acid  Structure-Activity
       Relationship  Support, Non-U.S. Gov't  Support, U.S. Gov't, P.H.S.
       T-Lymphocytes/*MICROBIOLOGY  Tumor Cells, Cultured  Viral
       Proteins/BIOSYNTHESIS  Virulence  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

