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7172299 
Journal Article 
Mitochondrial UCPs: New insights into regulation and impact 
Sluse, FE; Jarmuszkiewicz, W; Navet, R; Douette, P; Mathy, G; Sluse-Goffart, CM; , 
2006 
ELSEVIER SCIENCE BV 
AMSTERDAM 
480-485 
16597432 
WOS:000239481800026 
Uncoupling proteins (UCPs) are mitochondrial inner membrane proteins sustaining an inducible proton conductance. They weaken the proton electrochemical gradient built up by the mitochondrial respiratory chain. Brown fat UCP1 sustains a free fatty acid (FA)-induced purine nucleotide (PN)-inhibited proton conductance. Inhibition of the proton conductance by PN has been considered as a diagnostic of UCP activity. However, conflicting results have been obtained in isolated mitochondria for UCP homologues (i.e., UCP2, UCP3, plant UCP, and protist UCP) where the FFA-activated proton conductance is poorly sensitive to PN under resting respiration conditions. Our recent work clearly indicates that the membranous coenzyme Q, through its redox state, represents a regulator of the inhibition by PN of FFA-activated UCP1 homologues under phosphorylating respiration conditions. Several physiological roles of UCPs have been suggested, including a control of the cellular energy balance as well as the preventive action against oxidative stress. In this paper, we discuss new information emerging from comparative proteomics about the impact of UCPs on mitochondrial physiology, when recombinant UCP1 is expressed in yeast and when UCP2 is over-expressed in hepatic mitochondria during steatosis. (c) 2006 Elsevier B.V. All rights reserved. 
14th European Bioenergetic Conference 
Moscow, RUSSIA