title: Identification of a novel negative retinoic acid responsive element in the promoter of the human matrix Gla protein gene.
abstract: The vitamin K-dependent matrix Gla protein (MGP) is synthesized in a wide variety of tissues such as lung, heart, kidney, cartilage, and bone. Expression of the MGP gene is regulated by various growth factors, steroid hormones, and the vitamin A metabolite retinoic acid (RA). In this report, we present evidence that RA down-regulates MGP gene expression in different rat and human cell lines via endogenous retinoid receptors [RA receptor (RAR) and retinoid X receptor (RXR)]. Repression of the human MGP (hMGP) gene is specifically mediated by ligand-activated RAR and RXR. Deletion analysis led to the identification of a novel negative response element (NRE) within the hMGP promoter. DNA binding studies performed with bacterially expressed RAR/RXR reveal the formation of a specific heterodimer/NRE complex. Furthermore, electrophoretic mobility-shift assays performed with proteins from RA-treated cells show that endogenous RAR/RXR binds to the NRE. We demonstrate that the NRE contains a CCAAT box and that both RAR/RXR and CCAAT-binding proteins such as c/EBP beta recognize this common regulatory sequence in the hMGP promoter. Our results indicate that RA-mediated repression of the hMGP gene is due to binding of liganded RAR/RXR to a novel negative RA response element.
authors.affiliation: Fakultät für Biologie der Universität Freiburg, Institut für Experimentelle Krebsforschung, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Kirfel
authors.forename: M
authors.initials: M
authors.lastname: Kelter
authors.forename: L M
authors.initials: LM
authors.lastname: Cancela
authors.forename: P A
authors.initials: PA
authors.lastname: Price
authors.forename: R
authors.initials: R
authors.lastname: Schüle
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002135:Calcium-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics*; D002460:Cell Line; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D016326:Extracellular Matrix Proteins; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D009838:Oligodeoxyribonucleotides / Q000737:chemistry / Q000378:metabolism; D011401:Promoter Regions, Genetic; D051381:Rats; D018168:Receptors, Retinoic Acid / Q000737:chemistry / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis; D047488:Retinoid X Receptors; D017384:Sequence Deletion; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D014162:Transfection; D014212:Tretinoin / Q000494:pharmacology*; D014812:Vitamin K / Q000378:metabolism; D000097568:Matrix Gla Protein
chemical_list: D002135:Calcium-Binding Proteins; D004247:DNA; D004268:DNA-Binding Proteins; D016326:Extracellular Matrix Proteins; D009838:Oligodeoxyribonucleotides; D018168:Receptors, Retinoic Acid; D011994:Recombinant Proteins; D047488:Retinoid X Receptors; D014157:Transcription Factors; D014212:Tretinoin; D014812:Vitamin K; D000097568:Matrix Gla Protein