       Document 0711
 DOCN  M9640711
 TI    Modulation of Tax and PKA-mediated expression of HTLV-I promoter via
       cAMP response element binding and modulator proteins CREB and CREM.
 DT    9604
 AU    Bodor J; Walker W; Flemington E; Spetz AL; Habener JF; Laboratory of
       Molecular Endocrinology, Massachusetts General; Hospital (WEL320),
       Howard Hughes Medical Institute, Boston 02114,; USA.
 SO    FEBS Lett. 1995 Dec 27;377(3):413-8. Unique Identifier : AIDSLINE
       MED/96140558
 AB    Nuclear proteins of the human peripheral blood T lymphocytes that bind
       to the CREs located within three 21-bp repeat enhancers of the HTLV-I
       promoter belong to the CREB/CREM family of bZIP transcription factors.
       It has been shown previously that Tax enhances transactivation of these
       CREs by direct interactions with the bZIP domain of the transcription
       factors to stabilize DNA-binding. We show that CREB and CREM bind all
       three CRE sequences of the HTLV-I promoter which are important
       determinants in Tax-elicited transactivation as well as PKA-mediated
       activation of the HTLV-I promoter. Tax and PKA activate transcription
       from a HTLV-I-LTR CAT reporter plasmid transfected to NIH 3T3 cells, and
       CREM attenuates the activation. In the context of a GAL4 CREB fusion
       protein in which the DNA-binding bZIP domain of CREB is replaced by GAL4
       binding domain, a single amino acid substitution of serine-133,
       phosphorylated by PKA and critical for the transactivation function of
       CREB, attenuates both Tax and PKA-mediated transcriptional responses.
       These observations suggest that Tax enhances CREB-mediated
       transactivation of the HTLV-I promoter by a mechanism apart from, and/or
       in addition to, the reported stabilization of DNA-binding by interaction
       with the bZIP domain of CREB.
 DE    Animal  Base Sequence  Binding Sites  Cyclic AMP-Dependent Protein
       Kinases/METABOLISM  DNA-Binding Protein, Cyclic
       AMP-Responsive/METABOLISM  DNA-Binding Proteins/METABOLISM  Human
       HTLV-I/*GENETICS  Mice  Molecular Sequence Data  Nuclear
       Proteins/METABOLISM  *Promoter Regions (Genetics)  Protein Binding
       Proteins/METABOLISM  *Repetitive Sequences, Nucleic Acid  Support,
       Non-U.S. Gov't  Support, U.S. Gov't, P.H.S.  T-Lymphocytes/METABOLISM
       *Trans-Activation (Genetics)  *Transcription, Genetic  Transfection  3T3
       Cells  JOURNAL ARTICLE

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

