Format

Send to

Choose Destination
Nucleic Acids Res. 1996 May 1;24(9):1695-701.

Repression by a differentiation-specific factor of the human cytomegalovirus enhancer.

Author information

1
Department of Molecular Genetics, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA.

Abstract

We detected a novel nuclear protein, MRF, that binds to multiple sites on the modulator which is located upstream of the human cytomegalovirus major immediate early gene enhancer. The expression of MRF is differentiation specific; the DNA binding activity is present in nuclear extracts from undifferentiated Tera-2 and THP-1 cells, but significantly reduced after these cells are induced to differentiate. In undifferentiated cells the enhancer activity is repressed by the modulator and upon differentiation the enhancer becomes active. Competitive binding assays demonstrate that MRF requires the presence of multiple A+T stretches for binding to DNA, rather than binding to a specific DNA sequence. Mutations of these stretches in the modulator reduce the binding activity of MRF, as well as the repressing activity on the enhancer. These results suggest that MRF may act as a repressor of enhancer function. We propose that MRF binds over the entire modulator and exerts repressor activity.

PMID:
8649988
PMCID:
PMC145859
DOI:
10.1093/nar/24.9.1695
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Silverchair Information Systems Icon for PubMed Central
Loading ...
Support Center