A negative regulatory element in the promoter region of the rat alpha 2A-adrenergic receptor gene overlaps an SP1 consensus binding site.
Biochem J
; 311 ( Pt 2): 541-7, 1995 Oct 15.
Article
in En
| MEDLINE
| ID: mdl-7487893
ABSTRACT
Three subtypes of alpha 2-adrenergic receptors (alpha 2A, alpha 2B and alpha 2C) have been described that differ in their primary sequence and tissue-specific expression and are encoded by three distinct genes. Previous work has shown that the human alpha 2A-adrenergic receptor gene promoter consists of a TATA-box (TATAAA), palindromic sequence (CCCACGTGGG) and GC-box (GGGGCGG) motif. Sequence analysis of the putative promoter region of the rat alpha 2A-adrenergic receptor gene showed that these promoter regions are conserved in their sequence and relative location. We analysed the transcriptional activity of these regions using RINm5F, a rat insulinoma cell line that expresses the endogenous alpha 2A-adrenergic receptor gene. These results showed that the region from -484 to -92 has a negative effect on transcription, as deletion of this region in alpha 2A-adrenergic receptor gene-chloramphenicol acetyltransferase reporter constructs increased reporter gene activity. This region included the GC-box sequence which is a consensus binding site for the nuclear factor SP1, which is a positive activator of transcription. Gel-mobility-shift assays and supershift assays with an antibody that recognizes SP1 showed binding of the SP1 nuclear factor as well as other nuclear factors to this GC-box region. Additional nuclear factors bind to the downstream palindromic region. We suggest that positive- and negative-acting nuclear factors contribute to the activity of the alpha 2-adrenergic receptor promoter.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Genes, Regulator
/
Promoter Regions, Genetic
/
Receptors, Adrenergic, alpha-2
/
CCAAT-Enhancer-Binding Proteins
/
DNA-Binding Proteins
Limits:
Animals
/
Humans
Language:
En
Journal:
Biochem J
Year:
1995
Document type:
Article
Affiliation country:
United States