Document 0765
 DOCN  M9460765
 TI    Characterization of a family of related cellular transcription factors
       which can modulate human immunodeficiency virus type 1 transcription in
       vitro.
 DT    9404
 AU    Yoon JB; Li G; Roeder RG; Laboratory of Biochemistry and Molecular
       Biology, Rockefeller; University, New York, New York 10021.
 SO    Mol Cell Biol. 1994 Mar;14(3):1776-85. Unique Identifier : AIDSLINE
       MED/94158849
 AB    LBP-1 is a cellular protein which binds strongly to sequences around the
       human immunodeficiency virus type 1 (HIV-1) initiation site and weakly
       over the TATA box. We have previously shown that LBP-1 represses HIV-1
       transcription by inhibiting the binding of TFIID to the TATA box. Four
       similar but distinct cDNAs encoding LBP-1 (LBP-1a, -b, -c, and -d) have
       been isolated. These are products of two related genes, and each gene
       encodes two alternatively spliced products. Comparison of the amino acid
       sequence of LBP-1 with entries in the available protein data bases
       revealed the identity of LBP-1c to alpha-CP2, an alpha-globin
       transcription factor. These proteins are also homologous to Drosophila
       melanogaster Elf-1/NTF-1, an essential transcriptional activator that
       functions during Drosophila embryogenesis. Three of the recombinant
       LBP-1 isoforms show DNA binding specificity identical to that of native
       LBP-1 and bind DNA as a multimer. In addition, antisera raised against
       recombinant LBP-1 recognize native LBP-1 from HeLa nuclear extract.
       Functional analyses in a cell-free transcription system demonstrate that
       recombinant LBP-1 specifically represses transcription from a wild-type
       HIV-1 template but not from an LBP-1 mutant template. Moreover, LBP-1
       can function as an activator both in vivo and in vitro, depending on the
       promoter context. Interestingly, one isoform of LBP-1 which is missing
       the region of the Elf-1/NTF-1 homology is unable to bind DNA itself and,
       presumably through heteromer formation, inhibits binding of the other
       forms of LBP-1, suggesting that it may function as a dominant negative
       regulator.
 DE    Amino Acid Sequence  Base Sequence  Binding Sites  Cloning, Molecular
       Comparative Study  DNA Primers/CHEMISTRY  DNA-Binding Proteins/*GENETICS
       *Gene Expression Regulation, Viral  Genes, Structural  Hela Cells  Human
       HIV-1/*GENETICS  Molecular Sequence Data  Recombinant Proteins
       Repressor Proteins/*GENETICS  Restriction Mapping  Sequence Alignment
       Sequence Homology, Amino Acid  Support, Non-U.S. Gov't  Support, U.S.
       Gov't, P.H.S.  Transcription Factors/*GENETICS  Transcription, Genetic
       JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
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