Binding of multiple factors to the MMTV promoter in crude and fractionated nuclear extracts.
Hormone activation of MMTV transcription results in the establishment of a tightly bound transcription factor complex at the promoter (Cordingley et al., Cell 48, 261-270, 1987). We have characterized two fractionable binding activities which participate in this complex. One factor, previously identified as the mouse homologue of NF-1 (or CTF), protects sequences -82 to -56 from exonuclease III digestion in vitro. Sequences protected by a second factor (-42 to -4) span the TATA box of the promoter, suggesting that the binding activity in this fraction is equivalent to the HeLa cell transcription factor TFIID (Sawadogo and Roeder, Cell 43, 165-175, 1986). The downstream boundary of exonuclease protection by the putative TATA-binding factor is -4; DNase1 footprinting of this fraction, however, showed additional protection of discrete sites downstream of the cap site. The apparent concentration and promoter-specific binding activity of both factors is unaffected by hormone treatment of the cells.
Cordingley
M G
MG
Hormone Action and Oncogenesis Section, National Cancer Institute, Bethesda, MD 20892.
Hager
G L
GL
D000818:Animals; D002467:Cell Nucleus / Q000502:physiology; D002874:Chromosome Mapping; D004268:DNA-Binding Proteins / Q000235:genetics / Q000302:isolation & purification; D003850:Deoxyribonuclease I; D005090:Exodeoxyribonucleases; D005786:Gene Expression Regulation / Q000187:drug effects*; D005938:Glucocorticoids / Q000494:pharmacology*; D066298:In Vitro Techniques; D008324:Mammary Tumor Virus, Mouse / Q000235:genetics*; D051379:Mice; D011401:Promoter Regions, Genetic; D011965:Receptors, Glucocorticoid / Q000502:physiology; D012045:Regulatory Sequences, Nucleic Acid; D014157:Transcription Factors / Q000235:genetics* / Q000302:isolation & purification; D014407:Tumor Cells, Cultured
D004268:DNA-Binding Proteins; D005938:Glucocorticoids; D011965:Receptors, Glucocorticoid; D014157:Transcription Factors; D005090:Exodeoxyribonucleases; C020133:exodeoxyribonuclease III; D003850:Deoxyribonuclease I