title: Functional interaction between peroxisome proliferator-activated receptors-alpha and Mef-2C on human carnitine palmitoyltransferase 1beta (CPT1beta) gene activation.
abstract: Muscle-type carnitine palmitoyltransferase 1 (CPT1beta) is considered to be the gene that controls fatty acid mitochondrial beta-oxidation. A functional peroxisome proliferator-activated receptor (PPAR) responsive element (PPRE) and a myocite-specific (MEF2) site that binds MEF2A and MEF2C in the promoter of this gene had been previously identified. We investigated the roles of the PPRE and the MEF2 binding sites and the potential interaction between PPARalpha and MEF2C regulating the CPT1beta gene promoter. Mutation analysis indicated that the MEF2 site contributed to the activation of the CPT1beta promoter by PPAR in C2C12 cells. The reporter construct containing the PPRE and the MEF2C site was synergistically activated by co-expression of PPAR, retinoid X receptor (RXR) and MEF2C in non-muscle cells. Moreover, protein-binding assays demonstrated that MEF2C and PPAR specifically bound to one another in vitro. Also for the synergistic activation of the CPT1beta gene promoter by MEF2C and PPARalpha-RXRalpha, a precise arrangement of its binding sites was essential.
authors.affiliation: Department of Biochemistry and Molecular Biology, School of Pharmacy, University of Barcelona, Avenue Diagonal 643, E-08028 Barcelona, Spain.
authors.forename: Angel
authors.initials: A
authors.lastname: Baldán
authors.forename: Joana
authors.initials: J
authors.lastname: Relat
authors.forename: Pedro F
authors.initials: PF
authors.lastname: Marrero
authors.forename: Diego
authors.initials: D
authors.lastname: Haro
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002334:Carnitine O-Palmitoyltransferase / Q000235:genetics*; D002460:Cell Line; D006168:Guinea Pigs; D006801:Humans; D026161:MADS Domain Proteins; D064326:MEF2 Transcription Factors; D018006:Myogenic Regulatory Factors / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism*; D018168:Receptors, Retinoic Acid / Q000378:metabolism; D047488:Retinoid X Receptors; D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation
chemical_list: D026161:MADS Domain Proteins; D064326:MEF2 Transcription Factors; C578040:MEF2C protein, human; D018006:Myogenic Regulatory Factors; D018160:Receptors, Cytoplasmic and Nuclear; D018168:Receptors, Retinoic Acid; D047488:Retinoid X Receptors; D014157:Transcription Factors; D002334:Carnitine O-Palmitoyltransferase