Molecular Endocrinology, Vol 9, 1180-1192, Copyright © 1995 by Endocrine Society

ARTICLES

Role of the TATA box in transcription of the mouse mammary tumor virus long terminal repeat

P Kusk, KE Carlson, BS Warren and GL Hager
Laboratory of Molecular Virology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.

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.

This article has been cited by other articles:

				F. Rouault, S. B. Nejad Asl, S. Rungaldier, E. Fuchs, B. Salmons, and W. H. Gunzburg Promoter Complex in the Central Part of the Mouse Mammary Tumor Virus Long Terminal Repeat J. Virol., November 15, 2007; 81(22): 12572 - 12581. [Abstract] [Full Text] [PDF]

				H. Torrance, W. Giffin, D. J. Rodda, L. Pope, and R. J. G. Hache Sequence-specific Binding of Ku Autoantigen to Single-stranded DNA J. Biol. Chem., August 14, 1998; 273(33): 20810 - 20819. [Abstract] [Full Text] [PDF]

				P. Kusk, S. John, G. Fragoso, J. Michelotti, and G. L. Hager Characterization of an NF-1/CTF Family Member as a Functional Activator of the Mouse Mammary Tumor Virus Long Terminal Repeat 5' Enhancer J. Biol. Chem., December 6, 1996; 271(49): 31269 - 31276. [Abstract] [Full Text] [PDF]

				B. S. Warren, P. Kusk, R. G. Wolford, and G. L. Hager Purification and Stabilization of Transcriptionally Active Glucocorticoid Receptor J. Biol. Chem., May 10, 1996; 271(19): 11434 - 11440. [Abstract] [Full Text] [PDF]