       Document 0644
 DOCN  M9630644
 TI    Role of the TATA box in transcription of the mouse mammary tumor virus
       long terminal repeat.
 DT    9603
 AU    Kusk P; Carlson KE; Warren BS; Hager GL; Laboratory of Molecular
       Virology, National Cancer Institute,; National Institutes of Health,
       Bethesda, Maryland 20892, USA.
 SO    Mol Endocrinol. 1995 Sep;9(9):1180-92. Unique Identifier : AIDSLINE
       MED/96064300
 AB    An in vitro transcription system from mammary cells was established to
       study transcription of the long terminal repeat (LTR) of the mouse
       mammary tumor virus (MMTV). Experiments with progressive 5'-deletion
       constructs of the MMTV LTR revealed that a 19-base pair (bp) region from
       -41 to -23 bp, encompassing the TATA box and flanking DNA sequence, was
       as transcriptionally active as larger promoter constructs, both in
       nuclear extracts from human mammary cell lines (T47D and MCF7) and a
       nonmammary cell line (HeLa). The cell-free system was capable of
       supporting transcriptional induction by factors binding upstream of the
       TATA box, however, since purified glucocorticoid receptor-induced
       transcription in larger promoter constructs encompassing the MMTV
       hormone-responsive elements. Transcription from two other promoters, the
       adenovirus major late promoter and the human immunodeficiency virus LTR,
       also revealed a significant transcriptional contribution of upstream
       elements. The 19-bp TATA region from the MMTV LTR was shown to have
       considerably more activity in this transcription system than comparable
       TATA regions from other promoters. Sequences critical to the MMTV TATA
       region were evaluated by single base pair mutagenesis and found to
       comprise a consensus TATA box sequence, TATAAAA, as well as a single A
       just upstream of the TATAAAA sequence. Thus, the high level of basal
       transcription observed with the TATA region from MMTV is due to a
       perfect consensus TATA box sequence and a single base immediately 5'
       adjacent. It is likely that the high basal rate of transcription
       observed with this TATA box region on histone-free templates represents
       an inappropriate level of basal expression and that a complete
       evaluation of transactivation mechanisms in this system will require the
       recapitulation in vitro of the chromatin-mediated repressive state that
       exists in vivo.
 DE    Base Sequence  Binding Sites  Breast Neoplasms  Comparative Study  DNA,
       Viral/*CHEMISTRY  Hela Cells  Human  Mammary Tumor Viruses,
       Mouse/*GENETICS  Molecular Sequence Data  Nuclear Proteins  Promoter
       Regions (Genetics)  *Repetitive Sequences, Nucleic Acid  *Transcription,
       Genetic  Tumor Cells, Cultured  *TATA Box  JOURNAL ARTICLE

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

