Uncoupling protein

An uncoupling protein is a mitochondrial inner membrane protein that can dissipate the proton gradient before it can be used to provide the energy for oxidative phosphorylation.

There are five types known in mammals:
 * UCP1, also known as thermogenin
 * UCP2
 * UCP3
 * SLC25A27, also known as "UCP4"
 * SLC25A14, also known as "UCP5"

Uncoupling proteins play a role in normal physiology, as in hibernation, because the energy is used to generate heat (see thermogenesis) instead of producing ATP. However, other substances such as 2,4-Dinitrophenol and CCCP also serve the same uncoupling function, and are considered poisonous. Ethanol and salicyclic acid are also uncoupling agents and will deplete the body of ATP and increase body temperature if taken in excess.