title: The human uncoupling protein-3 gene promoter requires MyoD and is induced by retinoic acid in muscle cells.
abstract: The uncoupling protein-3 (UCP-3) gene encodes for a mitochondrial protein expressed preferentially in skeletal muscle. UCP-3 mRNA is expressed in cultured muscle cells (C2C12 or L6E9) only when differentiated, at which stage UCP-3 is highly induced by all-trans retinoic acid (RA). Here we report that human UCP-3 promoter activity is dependent on MyoD and inducible by all trans-RA. The action of all trans-RA is increased by co-transfection with RA receptor (RAR). We have characterized the RA response element that controls the induction by RA in the 5' noncoding region of the UCP-3 gene. Deletion and point-mutation analysis of the hUCP-3 promoter led us to identify a direct-repeat element with one base-pair spacing (DR1) at position -71/-59 responsible for the induction by RA of the activity of the promoter. This DR1 element bound a nuclear protein complex from muscle cells that contain RAR and retinoid X receptor (RXR). In the absence of this element, the promoter became unresponsive to RA, but it was still dependent on MyoD. In conclusion, it has been established that UCP-3 gene promoter activity is dependent on MyoD, and the first regulatory pathway for UCP-3 gene promoter regulation has been recognized by identifying RA as a transcriptional activator of the gene.
authors.affiliation: Departament de Bioquimica i Biologia Molecular, Universitat de Barcelona, Avda Diagonal 645, 08028 Barcelona, Spain.
authors.forename: G
authors.initials: G
authors.lastname: Solanes
authors.forename: N
authors.initials: N
authors.lastname: Pedraza
authors.forename: R
authors.initials: R
authors.lastname: Iglesias
authors.forename: M
authors.initials: M
authors.lastname: Giralt
authors.forename: F
authors.initials: F
authors.lastname: Villarroya
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics; D002460:Cell Line; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007473:Ion Channels; D024101:Mitochondrial Proteins; D018482:Muscle, Skeletal / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D017570:MyoD Protein / Q000378:metabolism*; D017354:Point Mutation; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D018168:Receptors, Retinoic Acid / Q000378:metabolism; D020218:Response Elements / Q000235:genetics; D047488:Retinoid X Receptors; D017384:Sequence Deletion; D014157:Transcription Factors / Q000378:metabolism; D014212:Tretinoin / Q000494:pharmacology*; D000071247:Uncoupling Protein 3
chemical_list: D002352:Carrier Proteins; D007473:Ion Channels; D024101:Mitochondrial Proteins; D017570:MyoD Protein; D012333:RNA, Messenger; D018168:Receptors, Retinoic Acid; D047488:Retinoid X Receptors; D014157:Transcription Factors; C000604392:UCP3 protein, human; D000071247:Uncoupling Protein 3; D014212:Tretinoin