Cholinergic agonist-induced binding of adrenomedullary nuclear proteins to the rat preproenkephalin promoter.
Cholinergic receptors are well-recognized modulators of transmitter release and biosynthesis with newly identified actions mediated through trans-acting DNA binding proteins affecting gene expression at cis-acting regulatory elements. In the case of the rat preproenkephalin (ppEnk) gene, we have identified changes in ppEnk DNA binding proteins detected by gel mobility shift assay that correlate with a cholinergic induction of ppEnk RNA levels. Antibody competition experiments implicate Fos-like and Jun-like transcription factors in this phenomenon. Methylation interference footprinting identified two cholinergic-inducible enhancements in the regions -155 to -149 and -185 to -173 (BETA1 site). An additional footprinted region at the BETA2 site (-137 to -132) was unaffected by cholinergic agonist treatment. These footprint features are significantly different from those obtained from the striatum after identical cholinergic drug treatments. We speculate that basal as well as cholinergic agonist responsive transcription factors account for tissue-specific differences in ppEnk gene expression. Further characterization of these cholinergic agonist-inducible events will require functional analysis of footprinted domains to evaluate the in vivo role of these putative gene regulatory elements.
La Gamma
E F
EF
HSC 11-060, Departments of Pediatrics and Neurobiology & Behavior, State University of New York at Stony Brook, Stony Brook, New York 11794-8111, USA.
Decristofaro
J
J
Weisinger
G
G