Genomic organization and regulation by dietary fat of the uncoupling protein 3 and 2 genes

Biochem Biophys Res Commun. 1999 Mar 5;256(1):27-32. doi: 10.1006/bbrc.1999.0239.


Uncoupling protein-1 (UCP1) dissipates the transmitochondrial proton gradient as heat. UCP2 and UCP3 are two recently discovered homologues that also have uncoupling activity and thus presumably have a role in energy homeostasis. We now report the genomic structure of murine UCP3 (7 exons) and UCP2 (8 exons). UCP3 is approximately 8 kilobases upstream of UCP2. An UCP3 variant mRNA, UCP3S, was also found and characterized. The effect of a high fat diet (45% versus 10%) on UCP3 and UCP2 mRNA levels was measured. Eating the 45% fat diet for eight weeks caused greater weight gain in AKR and C57BL/6J mice than in the obesity-resistant A/J mice. The high fat diet increased muscle UCP3 expression twofold in C57BL/6J animals. UCP2 expression increased slightly on the 45% fat diet in white adipose of AKR mice, but not in A/J or C57BL/6J mice. In skeletal muscle, UCP2 expression showed little variation with diet. Thus, UCP2 and UCP3 expression levels change in response to diet-induced obesity, but the changes are modest and depend on the tissue and genotype. The data suggest that it is not a reduction in UCP2 or UCP3 expression that causes obesity in the susceptible mice.

MeSH terms

  • Adipose Tissue / metabolism
  • Alternative Splicing
  • Amino Acid Sequence
  • Animals
  • Carrier Proteins / genetics*
  • Cloning, Molecular
  • Dietary Fats / administration & dosage
  • Dietary Fats / pharmacology*
  • Disease Susceptibility
  • Exons / genetics
  • Gene Expression Regulation*
  • Humans
  • Ion Channels
  • Membrane Transport Proteins*
  • Mice
  • Mice, Inbred Strains
  • Mitochondrial Proteins*
  • Molecular Sequence Data
  • Muscle, Skeletal / metabolism
  • Obesity / chemically induced
  • Obesity / genetics
  • Polymerase Chain Reaction
  • Protein Isoforms / genetics
  • Proteins / genetics*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Sequence Homology, Amino Acid
  • Uncoupling Protein 2
  • Uncoupling Protein 3


  • Carrier Proteins
  • Dietary Fats
  • Ion Channels
  • Membrane Transport Proteins
  • Mitochondrial Proteins
  • Protein Isoforms
  • Proteins
  • RNA, Messenger
  • UCP2 protein, human
  • UCP3 protein, human
  • Ucp2 protein, mouse
  • Ucp3 protein, mouse
  • Uncoupling Protein 2
  • Uncoupling Protein 3

Associated data

  • GENBANK/AF053352