First evidence and characterization of an uncoupling protein in fungi kingdom: CpUCP of Candida parapsilosis

An uncoupling protein (UCP) was identified in mitochondria from Candida par apsilosis (CpUCP), a nonfermentative parasitic yeast, CpUCP Nas immunodetec ted using polyclonal antibodies raised against plant UCP. Activity of CpUCP , investigated in mitochondria depleted of free fatty acids, was stimulated by Linoleic acid (LA) and inhibited by GTP, Activity of CpUCP enhanced sta le 4 respiration by decreasing Delta Psi and lowered the ADP/O ratio. Thus, it was able to divert energy from oxidative phosphorylation. The voltage d ependence of electron flux indicated that LA had a pure protonophoretic eff ect. The discovery of CpUCP proves that UCP-like proteins occur in the four eukaryotic kingdoms: animals, plants, fungi and protists. (C) 2000 Federat ion of European Biochemical Societies.