The uncoupling protein, thermogenin

Int J Biochem Cell Biol. 1998 Jan;30(1):7-11. doi: 10.1016/s1357-2725(97)00065-4.


The uncoupling protein (UCP) or thermogenin is a 33 kDa inner-membrane mitochondrial protein exclusive to brown adipocytes in mammals that functions as a proton transporter, allowing the dissipation as heat of the proton gradient generated by the respiratory chain and thereby uncoupling oxidative phosphorylation. Thermogenesis (heat production) in brown adipose tissue, which is activated in response to cold exposure or chronic overeating, depends largely on UCP activity. Norepinephrine, released from sympathetic terminals and acting via beta-adrenoceptors and cAMP, is the main positive regulator of both UCP synthesis and activity. Brown fat thermogenesis plays a critical role in thermoregulation and in overall energy balance, at least in rodents. Manipulation of thermogenesis, whether through UCP or through analogous uncoupling proteins, could be an effective strategy against obesity.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Adipose Tissue, Brown / metabolism*
  • Animals
  • Body Temperature Regulation / physiology
  • Carrier Proteins / chemistry
  • Carrier Proteins / metabolism*
  • Cold Temperature
  • Energy Metabolism / physiology*
  • Hot Temperature
  • Humans
  • Ion Channels
  • Ion Transport / physiology
  • Membrane Proteins / chemistry
  • Membrane Proteins / metabolism*
  • Mitochondria / metabolism*
  • Mitochondrial Proteins
  • Molecular Weight
  • Norepinephrine / metabolism
  • Obesity / metabolism
  • Oxidative Phosphorylation
  • Receptors, Adrenergic, beta / metabolism
  • Uncoupling Agents / chemistry
  • Uncoupling Agents / metabolism*
  • Uncoupling Protein 1


  • Carrier Proteins
  • Ion Channels
  • Membrane Proteins
  • Mitochondrial Proteins
  • Receptors, Adrenergic, beta
  • Uncoupling Agents
  • Uncoupling Protein 1
  • Norepinephrine