Abstract
In mammals, two kinds of adipose tissue are known to exist, i.e., white (WAT) and brown (BAT) adipose tissue. The physiological role of WAT is storage of excess energy as fat, whereas that of BAT is the expenditure of excess energy as heat. The uncoupling protein UCP1, which is specifically expressed in brown fat mitochondria, dissipates the proton electrochemical potential across the inner mitochondrial membrane, known as a driving force of ATP synthesis, and thus it dissipates excess energy in a form of heat. Because deficiency in effective expenditure of excess energy causes accumulation of this energy in the form of fat (i.e., obesity), it is very important to understand the energy metabolism in this tissue for the development of anti-obesity drugs. In this article, in addition to providing a brief introduction to the functional properties of BAT and UCP1, the results of our exploratory studies on protein components involved in the energy-dissipating function in BAT.
