Uncoupling proteins

The uncoupling proteins (UCPs) are proteins that, as their name indicates, will decouple, that means, separate processes that occur in normal conditions associated with one another. I am talking about the transport of electrons along the mitochondrial respiratory chain, and ATP synthesis. What happens is that, under normal conditions, if one of the processes stops, the other will be blocked. The presence of UCPs allows a process to can occur even in the absence of the other. Basically they are proteins of the inner mitochondrial membrane that will allow the return to the matrix of the H+ accumulated in the intermembrane space without passing through ATP synthase. 

Thus, it will continue to occur the transport of electrons in the respiratory chain, but this process will no longer be solely dependent on the synthesis of ATP. There are different isoforms of UCPs… UCP1, also known as thermogenin serves to produce heat in brown adipose tissue, thereby helping to maintain body heat in newborns and during hibernation, for example. The UCP2 is a protein essentially involved in the production of heat in the muscle; however, recent papers have suggested that this protein may also be important to regulate the levels of reactive oxygen species in mitochondria. The UCP3 is still not as well characterized, but it is thought that it may be related to the regulation of the levels of reactive oxygen species in skeletal muscle and cardiac muscle.