Abstract |
The endothelial nitric-oxide synthase gene is constitutively expressed in endothelial cells. Several transcriptionally active regulatory elements have been identified in the proximal promoter, including a GATA-2 and an Sp-1 binding site. Because they cannot account for the constitutive expression of endothelial nitric-oxide synthase gene in a restricted number of cells, we have searched for other cell-specific regulatory elements. By DNase I hypersensitivity mapping and deletion studies we have identified a 269-base pair activator element located 4.9 kilobases upstream from the transcription start site that acts as an enhancer. DNase I footprinting and linker-scanning experiments showed that several regions within the 269-base pair enhancer are important for transcription factor binding and for full enhancer activity. The endothelial specificity of this activation seems partly due to interaction between this enhancer in its native configuration and the promoter in endothelial cells. EMSA experiments suggested the implication of MZF-like, AP-2, Sp-1-related, and Ets-related factors. Among Ets factors, Erg was the only one able to bind to cognate sites in the enhancer, as found by EMSA and supershift experiments, and to activate the transcriptional activity of the enhancer in cotransfection experiments. Therefore, multiple protein complexes involving Erg, other Ets-related factors, AP-2, Sp-1-related factor, and MZF-like factors are important for the function of this enhancer in endothelial cells.
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Authors | Y Laumonnier, S Nadaud, M Agrapart, F Soubrier |
Journal | The Journal of biological chemistry
(J Biol Chem)
Vol. 275
Issue 52
Pg. 40732-41
(Dec 29 2000)
ISSN: 0021-9258 [Print] United States |
PMID | 11013235
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Nucleoproteins
- Transcription Factors
- NOS3 protein, human
- Nitric Oxide Synthase
- Nitric Oxide Synthase Type III
- Deoxyribonuclease I
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Topics |
- Base Sequence
- Binding Sites
- Cells, Cultured
- Deoxyribonuclease I
(pharmacology)
- Enhancer Elements, Genetic
- Humans
- Molecular Sequence Data
- Nitric Oxide Synthase
(genetics, metabolism)
- Nitric Oxide Synthase Type III
- Nucleoproteins
(metabolism)
- Promoter Regions, Genetic
- Transcription Factors
(metabolism)
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