UNCOUPLING PROTEIN-3 - A NEW MEMBER OF THE MITOCHONDRIAL CARRIER FAMILY WITH TISSUE-SPECIFIC EXPRESSION

Brown adipose tissue (BAT) and skeletal muscle are important sites of nonshivering thermogenesis. The uncoupling protein-1 (UCP1) is the mai n effector of nonshivering thermogenesis in BAT and the recently descr ibed ubiquitous UCP2 [1] has been implicated in energy balance. In an attempt to better understand the biochemical events underlying nonshiv ering thermogenesis in muscle, me screened a human skeletal muscle cDN A library and isolated three clones: UCP2, UCP3(L) and UCP3(S). The no vel UCP3 was 57% and 73% identical to human UCP1 and UCP2, respectivel y, highly skeletal muscle-specific and its expression was unaffected b y cold acclimation. This new member of the UCP family is a candidate p rotein for the modulation of the respiratory control in skeletal muscl e. (C) 1997 Federation of European Biochemical Societies.