Document 3301
 DOCN  M94A3301
 TI    Study of HIV1 Tat transactivation mechanism by using synthetic Tat
       protein and Tat peptides.
 DT    9412
 AU    Vives E; Charneau P; van Rietschoten J; Rochat H; Bahraoui E; CNRS URA
       1455, Marseille.
 SO    Int Conf AIDS. 1994 Aug 7-12;10(1):107 (abstract no. PA0046). Unique
       Identifier : AIDSLINE ICA10/94369274
 AB    OBJECTIVE: To study the structure function relationship of different Tat
       domains in the mechanism of HIV-1 Tat transactivation. METHODS:
       Full-length Tat protein Tat 1-86, the gene product of the first exon Tat
       1-72 and a panel of shorter peptides mimicking different regions of the
       primary structure of Tat protein were chemically synthesized and tested
       for their activity. RESULTS: Synthetic Tat 1-86 and Tat 1-72
       transactivated beta galactosidase activity in Hela cells containing the
       Lac Z gene under the control of HIV-1. The analysis of the activity of
       Tat 1-86 and Tat 1-72 with cysteine SH free or alkylated, showed that
       only the Tat fragments with deprotected cysteine residues (SH free)
       retain transactivation ability. In contrast, peptide Tat 1-48 was
       inactive with cysteine residues either free or protected. Similarly,
       other shorter synthetic peptides covering the different Tat domains were
       inactive. Interestingly, when peptides Tat 1-48 and Tat 38-60 were used
       simultaneously, a significant transactivation was obtained. This result
       suggests that both peptide domains are implicated in transactivation,
       probably by acting at two different sites. DISCUSSION AND CONCLUSION:
       This permits to propose a new fundamentally step in the understanding of
       the molecular mechanism of Tat transactivation.
 DE    Binding Sites  Gene Products, tat/CHEMICAL
       SYNTHESIS/*GENETICS/PHYSIOLOGY  Genes, tat  Hela Cells  Human
       HIV-1/*GENETICS/PHYSIOLOGY  Peptide Fragments/CHEMICAL
       SYNTHESIS/GENETICS/PHYSIOLOGY  Structure-Activity Relationship
       *Trans-Activation (Genetics)/PHYSIOLOGY  MEETING ABSTRACT

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