Year-end Sale % OFF 
Abstract
The steroid hormone-inducible promoter from mouse mammary tumor virus is associated with a distal negative regulatory element that represses its inherent basal activity. Deletion analysis localized the sequences required for repression to 64 base pairs of DNA between -427 and -364 with respect to the transcription initiation site. Transient transfection experiments with a series of linker scanning and small internal deletion mutations revealed two mutation-sensitive domains separated by a region of relative resistance to sequence alterations. DNase I footprinting and gel electrophoresis mobility shift experiments with crude nuclear extracts identified at least one protein-binding site within each of the two mutation-sensitive regions. An oligonucleotide corresponding to one of these sites is able to repress transcription, but only when linked to the promoter in multiple copies. This negative regulatory element functions synergistically with a promoter proximal negative element to mediate efficient promoter repression, selectively affecting basal relative to steroid hormone-induced transcription and thus increasing the ratio of promoter activity observed in the presence and absence of hormone.
Highlights
The steroid hormone-inducible promoter from moquuseence-specific DNA-bindingproteins that are required in mammary tumorvirus is associated witha distal neg- trans tomediate the appropriate transcriptional response
With a promoter proximalnegative element to mediate Cis-acting sequences required for steroid inducibility have efficient promoterrepression, selectively affecting been localized to thelong terminal repeats (LTRs) of proviral basal relative to steroid hormone-induced transcrip- DNA from about -200 to -80 with respect to thetranscription tion and increasing the ratio of promaoctetrivity initiation site (Ponta et al, 1985; Hynes et al, 1983; Majors observed in the presence and absence of hormone. and Varmus, 1983; Lee et al, 1984)
We demonstrate that the distinguish it from the promoterdistal NRE (dNRE) is composed of two mutation-sensitive domains between -427 and -364 and that each of these domains contains at least one recognition site for a sequence-specific DNA-binding protein
Summary
Competition studies demonstrated that thiseffect is mediated by a trans-acting nuclear factor, and exonuclease I11 footprinting was used to identify a protein-binding site between -167 andabout -140, sequences which overlap (Payvar et al, 1983)or are immediately adjacent to (Scheidereit et al, 1983) binding sites for the glucocorticoid hormone-receptor complex This element, which, for ease of discussion, we designate the promoterproximal NRE (pNRE) to distinguish it from the promoterdistal NRE (dNRE) described above, apparently cannot by itself mediate significant MMTV promoter repression in uiuo; once the dNREis deleted, further deletion of the HRE/pNRE has little or no effect on basal promoter activity (Morley et al, 1987). We demonstrate thatthis element functions synergistically with the pNRE imbedded within the HRE, selectivelyaffecting basal relative to steroid hormone-induced transcription
Sign-in/Register to view highlights & summary 
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
