The Biology of Mitochondrial Uncoupling Proteins

TABLE 1

Roles attributed to the different UCPs according to experimental methods

Method Demonstrated or proposed roles
UCP1 UCP2 UCP3
Liposome Proton leak Proton leak Proton leak
Yeast Proton leak Proton leak Proton leak
Transgenic mice Respiration uncoupling Not determined Proton leak or not
Increased oxidation
–/–mice Respiration uncoupling ATP increase or not Respiration uncoupling or not
Thermogenesis ROS scavenging ROS scavenging
Insulin secretion
Normal animals Cold-induced thermogenesis ROS scavenging ROS scavenging
Insulin secretion T3 thermogenesis
Diet-induced thermogenesis Diet-induced thermogenesis
Fatty acid oxidation Fatty acid oxidation
Human genetics Body fat content Resting metabolic rate Resting metabolics rate
Body fat content
Anorexia nervosa Anorexia nervosa
  • Transgenic mice refer to animals overexpressing UCP. Most biochemical studies supported a proton transport activity and a potential uncoupling activity of the UCPs. However, contrary to UCP1, analysis of normal mice or mice made null for Ucp2 or Ucp3 did not confirm the respiration uncoupling activity of UCP2 or UCP3.

This Article

  1. Diabetes vol. 53 no. suppl 1 S130-S135