Stably integrated mouse mammary tumor virus long terminal repeat DNA requires the octamer motifs for basal promoter activity

Détails

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Etat: Public
Version: de l'auteur⸱e
ID Serval
serval:BIB_19BC27CD2F79
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Stably integrated mouse mammary tumor virus long terminal repeat DNA requires the octamer motifs for basal promoter activity
Périodique
Molecular and Cellular Biology
Auteur⸱e⸱s
Buetti E.
ISSN
0270-7306 (Print)
Statut éditorial
Publié
Date de publication
02/1994
Volume
14
Numéro
2
Pages
1191-203
Notes
Journal Article Research Support, Non-U.S. Gov't --- Old month value: Feb
Résumé
In the mouse mammary tumor virus promoter, a tandem of octamer motifs, recognized by ubiquitous and tissue-restricted Oct transcription factors, is located upstream of the TATA box and next to a binding site for the transcription factor nuclear factor I (NF-I). Their function was investigated with mutant long terminal repeats under different transfection conditions in mouse Ltk- cells and quantitative S1 nuclease mapping of the transcripts. In stable transfectants, which are most representative of the state of proviral DNA with respect to both number of integrated DNA templates and chromatin organization, a long terminal repeat mutant of both octamer sites showed an average 50-fold reduction of the basal transcription level, while the dexamethasone-stimulated level was unaffected. DNase I in vitro footprinting assays with L-cell nuclear protein extracts showed that the mutant DNA was unable to bind octamer factors but had a normal footprint in the NF-I site. I conclude that mouse mammary tumor virus employs the tandem octamer motifs of the viral promoter, recognized by the ubiquitous transcription factor Oct-1, for its basal transcriptional activity and the NF-I binding site, as previously shown, for glucocorticoid-stimulated transcription. A deletion mutant with only one octamer site showed a marked base-level reduction at high copy number but little reduction at low copies of integrated plasmids. The observed transcription levels may depend both on the relative ratio of transcription factors to DNA templates and on the relative affinity of binding sites, as determined by oligonucleotide competition footprinting.
Mots-clé
Animals Base Sequence Binding Sites *CCAAT-Enhancer-Binding Proteins DNA, Viral/*genetics/*metabolism DNA-Binding Proteins/metabolism Deoxyribonuclease I L Cells (Cell Line) Mammary Tumor Virus, Mouse/*genetics Mice Molecular Sequence Data NFI Transcription Factors Nuclear Proteins/metabolism Plasmids *Promoter Regions (Genetics) *Repetitive Sequences, Nucleic Acid Restriction Mapping TATA Box Transcription Factors/metabolism Transcription, Genetic Transfection *Virus Integration Y-Box-Binding Protein 1
Pubmed
Web of science
Création de la notice
25/01/2008 14:25
Dernière modification de la notice
20/08/2019 12:50
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