title: GSK-3beta reduces cAMP-induced cholecystokinin gene expression by inhibiting CREB binding.
abstract: The cAMP signaling pathway stimulates cholecystokinin (CCK) gene transcription via CREB binding to a cAMP response element (CRE). In the present study we examined the function of glycogen synthase kinase-3beta (GSK-3beta) on cAMP-induced CCK gene transcription. Co-transfection of GSK-3beta reduced the cAMP-induced CCK promoter activity with approximately 80% and approximately 60% in SK-N-MC and PC12 cells, respectively. Binding of in vitro translated CREB to the CCK CRE(-80) promoter element was reduced following incubation with recombinant GSK-3beta. Finally, mutation of serine-129, which is a phosphorylation site for GSK-3beta, did not abolish cAMP-induced CREB-dependent transcription, and cAMP-mediated GAL4-CREB transcription was unaffected by co-transfection with GSK-3beta. We conclude that GSK-3beta regulates cAMP-induced CCK transcription by reducing CREB binding to the CRE(-80) element in the CCK promoter.
authors.affiliation: Department of Clinical Biochemistry, University Hospital Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark. tvoh@rh.dk
authors.forename: Thomas v O
authors.initials: Tv
authors.lastname: Hansen
authors.forename: Jens F
authors.initials: JF
authors.lastname: Rehfeld
authors.forename: Finn C
authors.initials: FC
authors.lastname: Nielsen
mesh_terms: D000818:Animals; D015153:Blotting, Western / Q000379:methods; D045744:Cell Line, Tumor; D002766:Cholecystokinin / Q000235:genetics / Q000378:metabolism*; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000494:pharmacology*; D017362:Cyclic AMP Response Element-Binding Protein / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004347:Drug Interactions; D024202:Electrophoretic Mobility Shift Assay / Q000379:methods; D005786:Gene Expression Regulation / Q000187:drug effects*; D038362:Glycogen Synthase Kinase 3 / Q000494:pharmacology*; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D009447:Neuroblastoma; D011485:Protein Binding / Q000502:physiology; D051381:Rats; D014162:Transfection / Q000379:methods
chemical_list: D017362:Cyclic AMP Response Element-Binding Protein; D005576:Colforsin; D002766:Cholecystokinin; D000242:Cyclic AMP; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; C000605508:Gsk3b protein, rat; D038362:Glycogen Synthase Kinase 3