Cloning of rat uncoupling protein-3 and uncoupling protein-2 cDNAs: their gene expression in rats fed high-fat diet

FEBS Lett. 1997 Nov 24;418(1-2):200-4. doi: 10.1016/s0014-5793(97)01381-1.


In order to elucidate energy balance in the skeletal muscle, we cloned cDNA of a homologue of uncoupling protein (UCP) from rat skeletal muscle. We also cloned rat UCP-2 cDNA from rat brown adipose tissue (BAT). The UCP cloned from rat skeletal muscle showed 57% and 72% identity with rat UCP-1 and UCP-2. The mRNA was expressed abundantly in the skeletal muscle, moderately in the BAT, and slightly in the white adipose tissue (WAT) with a major band at 2.5 kb and a minor band at 2.8 kb, while the UCP-2 gene expression was widely detected in the whole body with substantial levels in the WAT and with slight levels in the skeletal muscle and BAT. The rat UCP cloned in the present study showed 86% identity with the recently cloned human UCP-3, which was also expressed abundantly in the skeletal muscle with a signal of 2.4 kb. Therefore, the rat UCP was considered to be rat UCP-3. In rats fed high-fat diet the UCP-3 gene expression was augmented 2-fold in the skeletal muscle while UCP-2 mRNA levels were increased significantly (1.6-fold) in the epididymal WAT. Augmented expression of UCPs may provide defense against high-fat induced obesity and impairment of glucose metabolism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue / metabolism*
  • Adipose Tissue, Brown / metabolism
  • Amino Acid Sequence
  • Animals
  • Carrier Proteins / biosynthesis*
  • Carrier Proteins / chemistry
  • Cloning, Molecular
  • DNA, Complementary
  • Dietary Fats*
  • Epididymis
  • Gene Expression Regulation*
  • Humans
  • Ion Channels
  • Male
  • Membrane Transport Proteins*
  • Mitochondrial Proteins*
  • Molecular Sequence Data
  • Muscle, Skeletal / metabolism*
  • Organ Specificity
  • Protein Biosynthesis*
  • Proteins / chemistry
  • RNA, Messenger / biosynthesis
  • Rats
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Transcription, Genetic*
  • Uncoupling Protein 2
  • Uncoupling Protein 3


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

Associated data

  • GENBANK/AB006613
  • GENBANK/AB006614