Document 3334
 DOCN  M94A3334
 TI    Domain between V1 and V2 regions of HIV-1 gp120 is critical for virus
       infectivity.
 DT    9412
 AU    Wang WK; Essex M; Lee TH; Department of Cancer Biology, Harvard School
       of Public Health,; Boston, MA 02115.
 SO    Int Conf AIDS. 1994 Aug 7-12;10(1):10 (abstract no. 014A). Unique
       Identifier : AIDSLINE ICA10/94369241
 AB    OBJECTIVE: Between the first and second variable regions (V1 and V2) of
       HIV-1 gp120 is a conserved domain containing a relatively large number
       of charged residues. These residues were investigated for their role in
       viral infectivity. METHODS: Mutant proviruses each with an alanine
       substituted for one of 9 highly conserved charged residues in the domain
       between V1 and V2 of HIV-1 gp120 were generated by site-directed
       mutagenesis. Virus infectivity was monitored by reverse transcriptase.
       Envelope expression, processing and incorporation into virions were
       examined by western blot. A one-round complementation chloramphenicol
       acetyltransferase (CAT) assay was performed to study early steps of
       virus replication. RESULTS: Six of 9 mutant viruses had growth kinetics
       comparable to that of the wild type. Two mutant viruses showed a slight
       delay and one mutant with a substitution at position 180 had severely
       impaired infectivity. Additional substitutions at this position with
       residues of the same charge, opposite charge or no charge resulted in
       severely impaired infectivity. This impairment could not be attributed
       to global changes in gp120 conformation because expression and
       incorporation of envelope proteins into virions and recognition of
       mutants by conformation-dependent monoclonal antibodies were not
       affected. In a one-round replication assay, mutant virus with an alanine
       at position 180 had significantly reduced CAT activity. CONCLUSIONS: The
       domain flanked by V1 and V2 of gp120 is functionally involved in virus
       infectivity. Of the charged residues in this domain, aspartic acid at
       position 180 is most critical for early steps of virus replication.
       Previously, anti-V2 monoclonal antibodies that mapped to a region
       overlapping with residue 180 could block virus infectivity. Since this
       aspartic residue is conserved by all classes of HIV-1, it may be a
       potential target for future anti-viral designs.
 DE    Aspartic Acid/METABOLISM  Blotting, Western  Chloramphenicol
       Acetyltransferase/ANALYSIS  HIV Envelope Protein
       gp120/ANALYSIS/*GENETICS  HIV-1/*GENETICS/METABOLISM/PATHOGENICITY
       Mutagenesis, Site-Directed  MEETING ABSTRACT

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