Abstract
Cocaine‐ and amphetamine‐regulated transcript (CART) peptides in the nucleus accumbens (NAc) oppose the rewarding effects of cocaine. Since over expression of the transcription factor (TF) CREB likewise decreases cocaine reward we hypothesized that CREB regulates the CART gene in the rat NAc via interaction at a CART promoter CRE cis‐regulatory element. Electrophoretic mobility shift assays (EMSA) and TF‐antibody super shift assays (SS) with a CRE oligonucleotide identical in sequence to the CART gene CRE site revealed that CREB and ser133 phospho‐CREB from the rat NAc and pituitary‐derived GH3 cells bind to the CRE element of the CART promoter. Furthermore, chromatin immunoprecipitation assays performed with GH3 cells revealed an interaction between the CART promoter region containing the CRE element and both CREB and ser133 phospho‐CREB. To determine if CREB regulates CART expression in the NAc, Herpes simplex virus‐1 vectors (HSV‐CREB) that over expressed CREB were injected into the rat NAc. When compared to the effects of vectors expressing LacZ alone (HSV‐LacZ), HSV‐CREB increased CART mRNA and peptide levels in the NAc as determined by in situ hybridization and Western blotting. In summary, we identified CART as a CREB‐regulated gene in the NAc of rats. Finding CREB‐regulated genes in the NAc offers insight into the molecular mechanisms underlying cocaine's addictive properties.
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 call