Fatty acid interaction with mitochondrial uncoupling proteins.
The phenomena of fatty acid interaction with mitochondrial integral membrane proteins, namely uncoupling proteins (UCPs), are reviewed to emphasize the fatty acid cycling mechanism that has been suggested to explain the UCP function. Fatty acid-induced uncoupling is suggested to serve in bioenergetic systems, to set the optimum efficiency, and to tune the degree of coupling of oxidative phosphorylation. Fatty acid interaction with the "classic" uncoupling protein (UCP1) from mitochondria of thermogenic brown adipose tissue (BAT) is well known. UCP1 is considered to mediate purine nucleotide-sensitive uniport of monovalent unipolar anions, including anionic fatty acids. The return of protonated fatty acid leads to H+ uniport and uncoupling. Experiments supporting this mechanism are also reviewed for plant uncoupling mitochondrial protein (PUMP) and ADP/ATP carrier. The fatty acid cycling mechanism is predicted, as well for the recently discovered uncoupling proteins, UCP2 and UCP3.
Jezek
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Institute of Physiology, Department of Membrane Transport Biophysics, Academy of Sciences of the Czech Republic, Prague. jezek@sun1.biomed.cas.cz
D002001:Adipose Tissue, Brown / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites; D002352:Carrier Proteins / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism*; D005544:Forecasting; D006801:Humans; D007473:Ion Channels; D008565:Membrane Proteins / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins; D010944:Plants; D011510:Proteolipids / Q000378:metabolism; D013329:Structure-Activity Relationship; D014475:Uncoupling Agents / Q000378:metabolism*; D000071256:Uncoupling Protein 1
D002352:Carrier Proteins; D005227:Fatty Acids; D007473:Ion Channels; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D011510:Proteolipids; C000604371:UCP1 protein, human; D014475:Uncoupling Agents; D000071256:Uncoupling Protein 1; C020485:proteoliposomes