Recombinant human uncoupling protein-3 increases thermogenesis in yeast cells

FEBS Lett. 1999 Apr 1;448(1):57-61. doi: 10.1016/s0014-5793(99)00331-2.


The long form of human uncoupling protein-3 (hUCP3L) is highly homologous to thermogenin (UCPI), the uncoupling protein of brown fat mitochondria, but is expressed predominantly in skeletal muscle. Its putative role is to regulate the coupling efficiency of oxidative phosphorylation and thus thermogenesis in skeletal muscle, a major thermogenic tissue in higher mammals. To study the functional relevance of hUCP3L, the protein was expressed in yeast cells under the control of the galactose promoter. Expression of hUCP3L induced a series of phenotype changes in the yeast cells. The cellular growth and the mitochondrial membrane potential were both diminished. The portion of cellular respiration coupled to oxidative phosphorylation decreased from 57% to 11% (P<0.001) and the cellular heat production, as measured by direct microcalorimetry, was increased by 33.3 +/- 3.2% (P<0.001) after induction of UCP3L. These observations demonstrate for the first time the intrinsic thermogenic properties of hUCP3L in intact cells.

MeSH terms

  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cell Division
  • Hot Temperature
  • Humans
  • Ion Channels
  • Mitochondria / metabolism*
  • Mitochondria / physiology
  • Mitochondrial Proteins
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism*
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae / physiology
  • Uncoupling Protein 3


  • Carrier Proteins
  • Ion Channels
  • Mitochondrial Proteins
  • Recombinant Fusion Proteins
  • UCP3 protein, human
  • Uncoupling Protein 3