Cyclic adenosine 3',5'-monophosphate (cAMP) and cAMP responsive element-binding protein are involved in the transcriptional regulation of gonadotropin-releasing hormone (GnRH) receptor by GnRH and mitogen-activated protein kinase signal transduction pathway in GGH(3) cells.
Stimulation of mouse GnRH receptor promoter by a GnRH agonist (Buserelin), or by a cAMP analogue, significantly increased reporter (luciferase) activity. Overexpression of Raf-1, ERK1, or ERK2 partially blocked Buserelin-stimulated luciferase activity. In contrast, treatment with a mitogen-activated protein kinase (MAPK) kinase inhibitor (PD 98059) activated basal and Buserelin-stimulated luciferase activity in a dose-dependent manner. Transient transfection of the deleted cAMP response element expression vector followed by pretreatment with PD98059 prior to Buserelin stimulation showed that the transcriptional response was decreased compared to wild-type promoter. A gel-mobility shift assay using a probe containing the cAMP response element showed the presence of two specific protein-DNA complexes that contain one or more members of the cAMP responsive element-binding (CREB) protein family. These results suggest that cAMP and CREB participate in the GnRH activation of GnRH receptor promoter activity and that the MAPK cascade is involved in the negative regulation of basal and GnRH-stimulated GnRH receptor transcriptional activity.
Maya-Núñez
G
G
Oregon Regional Primate Research Center and Department of Physiology and Pharmacology, Oregon Health and Sciences University, Portland, Oregon 97201, USA.
Conn
P M
PM
D000818:Animals; D002460:Cell Line; D000242:Cyclic AMP / Q000502:physiology*; D017362:Cyclic AMP Response Element-Binding Protein / Q000502:physiology*; D005786:Gene Expression Regulation / Q000187:drug effects*; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D010902:Pituitary Gland / Q000378:metabolism; D011401:Promoter Regions, Genetic; D051381:Rats; D011966:Receptors, LHRH / Q000235:genetics*; D015398:Signal Transduction; D014158:Transcription, Genetic / Q000187:drug effects
D017362:Cyclic AMP Response Element-Binding Protein; D011966:Receptors, LHRH; D007987:Gonadotropin-Releasing Hormone; D000242:Cyclic AMP; D020928:Mitogen-Activated Protein Kinases