title: Mouse GnRH receptor gene expression is mediated by the LHX3 homeodomain protein.
abstract: Appropriate expression of GnRH receptor (GnRHR) is necessary for the correct regulation of the gonadotropins, LH and FSH, by GnRH. GnRHR is primarily expressed in the gonadotrope cells of the anterior pituitary, and a number of regulatory elements important for both basal and hormonal regulation of the gene have been identified. Using the gonadotrope-derived cell line, alpha T3-1, that endogenously expresses GnRHR, we have identified an ATTA element located at -298 relative to the transcriptional start site that is essential for basal expression of the GnRHR gene. LHX3, a member of the LIM homeodomain family, binds the -298 ATTA site in vitro as well as to the endogenous GnRHR promoter in vivo. Additionally, LHX3 specifically activates through this -298 ATTA site in transient transfection assays. LHX3 is essential for pituitary development and has been implicated in the regulation of a number of pituitary specific genes; however, this is the first report identifying its role in the regulation of GnRHR.
authors.affiliation: Department of Reproductive Medicine, the Biomedical Sciences Graduate Program, and the Center for Reproductive Science and Medicine, University of California San Diego, La Jolla, California 92093-0674, USA.
authors.forename: Shauna M
authors.initials: SM
authors.lastname: McGillivray
authors.forename: Janice S
authors.initials: JS
authors.lastname: Bailey
authors.forename: Rosha
authors.initials: R
authors.lastname: Ramezani
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Kirkwood
authors.forename: Pamela L
authors.initials: PL
authors.lastname: Mellon
mesh_terms: D000818:Animals; D001665:Binding Sites; D002460:Cell Line; D004247:DNA / Q000378:metabolism; D005786:Gene Expression Regulation; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology*; D060850:LIM-Homeodomain Proteins; D051379:Mice; D016296:Mutagenesis; D041681:NIH 3T3 Cells; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000502:physiology*; D010902:Pituitary Gland; D011401:Promoter Regions, Genetic / Q000235:genetics; D011966:Receptors, LHRH / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid; D014157:Transcription Factors; D014162:Transfection
chemical_list: D018398:Homeodomain Proteins; D060850:LIM-Homeodomain Proteins; C094898:Lhx3 protein; D009419:Nerve Tissue Proteins; D011966:Receptors, LHRH; D014157:Transcription Factors; D004247:DNA