A Novel Regulatory Pathway of Brown Fat Thermogenesis

• DOI: 10.1074/jbc.270.10.5666
• Publication Date: 2002-07-26T14:53:54Z
• Authors: Rosa Alvarez; Javier de Andrés; Pilar Yubero; Octavi Viñas; Teresa Mampel; Roser Iglesias; Marta Giralt; Francesc Villarroya
• Keywords: Thermogenin

The mitochondrial uncoupling protein (UCP) is responsible for the thermogenic function of brown fat, and it a molecular marker adipocyte cell type. Retinoic acid (RA) increased UCP mRNA levels severalfold in adipocytes differentiated culture. This induction was independent adrenergic pathways or synthesis. RA stimulated ucp gene expression regardless stage differentiation. In transient transfection experiments induced chloramphenicol acetyltransferase vectors driven by 4.5 kilobases 5′-noncoding region rat gene, co-transfection receptors enhanced action RA. receptor α more effective than retinoid X promoting action, whereas mixture two most effective. RA-responsive located at −2469/-2318 contains three motifs (between −2357 −2330) consensus half-sites characteristic retinoic response elements. 27-base pair sequence specifically binds purified as well related proteins from fat nuclei. conclusion, novel potential regulatory pathway development has been recognized identifying transcriptional activator gene.