Gonadotropin-releasing hormone-induced stimulation of the rat secretogranin II promoter involves activation of CREB.
To investigate the events involved in regulation of the secretogranin II (SgII) gene, luciferase reporter constructs were transfected into gonadotrope-derived, alphaT3-1 cells. DNA between -91 and -60 relative to the transcription start site was found to be required for GnRH induced SgII reporter gene activation. This region contains a consensus cAMP response element (CRE) and disruption of this CRE reduced GnRH responsiveness of the SgII promoter. CREB was shown to bind to the SgII CRE and transfection studies with a dominant-negative CREB mutant provided evidence that CREB is required for GnRH responsiveness of the SgII promoter. An expression vector for an inhibitor of the cAMP-dependent protein kinase was found to reduce the ability of cAMP or GnRH to activate the SgII-luciferase reporter gene. These studies offer evidence that GnRH-induced activation of the SgII promoter in the alphaT3-1 cell line requires cAMP-dependent protein kinase activity and a functional CRE within the 5'-flanking region of the gene.
Song
Seok Bean
SB
Department of Biochemistry, Institute of Biotechnology, Chungnam National University, Taejon 305-764, South Korea.
Rhee
Myungchull
M
Roberson
Mark S
MS
Maurer
Richard A
RA
Kim
Kyoon Eon
KE
D024506:5' Flanking Region; D000818:Animals; D002460:Cell Line; D002864:Chromogranins; D000242:Cyclic AMP / Q000494:pharmacology; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D017930:Genes, Reporter; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D051379:Mice; D011401:Promoter Regions, Genetic / Q000187:drug effects*; D011506:Proteins / Q000235:genetics*; D051381:Rats; D020218:Response Elements; D015533:Transcriptional Activation; D014162:Transfection
D002864:Chromogranins; D017362:Cyclic AMP Response Element-Binding Protein; D011506:Proteins; D007987:Gonadotropin-Releasing Hormone; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases