Thermogenic uncoupling has been proven only for UCP1 in brown adipose tissue. All other isoforms of UCPs are potentially acting in suppression of mitochondrial reactive oxygen species (ROS) production. In this contribution we show that BAT mitochondria can be uncoupled by lauric acid in the range of approximately 100 nM when endogenous fatty acids are combusted by carnitine cycle and beta-oxidation is properly separated from the uncoupling effect. Respiration increased up to 3 times when related to the lowest fatty acid content (BSA present plus carnitine cycle). We also illustrated that any effect leading to more coupled states leads to enhanced H2O2 generation and any effect resulting in uncoupling gives reduced H2O2 generation in BAT mitochondria. Finally, we report doubling of plant UCP transcript in cells as well as amount of protein detected by 3H-GTP-binding sites in mitochondria of shoots and roots of maize seedlings subjected to the salt stress.

Department No 75 Membrane Transport Biophysics Institute of Physiology Academy of Sciences of the Czech Republic Vídenská 1083 14220 Prague 4 Czech Republic

References provided by Crossref.org

Mitochondrial Uncoupling Proteins: Subtle Regulators of Cellular Redox Signaling

Absolute levels of transcripts for mitochondrial uncoupling proteins UCP2, UCP3, UCP4, and UCP5 show different patterns in rat and mice tissues