title: Mouse melanocortin-4 receptor gene 5'-flanking region imparts cell specific expression in vitro.
abstract: Weight homeostasis is exquisitely sensitive to changes in the abundance of melanocortin-4 receptor (MC4-R). To begin to understand the factors that regulate MC4-R gene expression, we determined there are no introns in the gene, there are multiple starts of transcription, and a cluster of 3' ends. A series of MC4-R-luciferase gene reporter chimerics was developed and transfected into cell lines expressing (UMR106; GT1-7; HEK293) and not expressing (Neuro 2A) endogenous MC4-R mRNA. The longest construct, which includes approximately 3.3 kb 5'-flanking, 425 bp 5'-untranslated (UTR) and 1852 bp 3'-flanking, significantly increased luciferase reporter gene expression 24-, 13-, and 3-fold compared to pGL3-basic when expressed in HEK293, UMR106, and GT1-7 cells, respectively. Deletion analysis of mMC4-R 5'-flanking cDNA identified full mMC4-R promoter activity within 178 bp upstream of the major start of transcription. The mMC4-R gene structure and reporter chimerics provide a fundamental framework for the identification of specific factors regulating MC4-R gene expression.
authors.affiliation: Research Centre for Developmental Medicine and Biology, Faculty of Medical and Health Sciences, University of Auckland, Auckland 1, New Zealand.
authors.forename: L M
authors.initials: LM
authors.lastname: Dumont
authors.forename: C S
authors.initials: CS
authors.lastname: Wu
authors.forename: C J
authors.initials: CJ
authors.lastname: Aschkenasi
authors.forename: J K
authors.initials: JK
authors.lastname: Elmquist
authors.forename: B B
authors.initials: BB
authors.lastname: Lowell
authors.forename: K G
authors.initials: KG
authors.lastname: Mountjoy
mesh_terms: D024509:3' Flanking Region / Q000235:genetics; D024506:5' Flanking Region / Q000235:genetics* / Q000502:physiology; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D005786:Gene Expression Regulation / Q000235:genetics*; D006801:Humans; D051379:Mice / Q000235:genetics*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D044105:Receptor, Melanocortin, Type 4; D018043:Receptors, Corticotropin / Q000235:genetics*; D016415:Sequence Alignment; D014018:Tissue Distribution; D014158:Transcription, Genetic / Q000235:genetics; D014407:Tumor Cells, Cultured
chemical_list: D012333:RNA, Messenger; D044105:Receptor, Melanocortin, Type 4; D018043:Receptors, Corticotropin