Jezek P, Engstová H, Zácková M, Vercesi A E, Costa A D, Arruda P, Garlid K D
Department of Membrane Transport Biophysics, Academy of Sciences of the Czech Republic, Prague.
Biochim Biophys Acta. 1998 Jun 10;1365(1-2):319-27. doi: 10.1016/s0005-2728(98)00084-x.
We hypothesize that fatty acid-induced uncoupling serves in bioenergetic systems to set the optimum efficiency and tune the degree of coupling of oxidative phosphorylation. Uncoupling results from fatty acid cycling, enabled by several phylogenetically specialized proteins and, to a lesser extent, by other mitochondrial carriers. It is suggested that the regulated uncoupling in mammalian mitochondria is provided by uncoupling proteins UCP-1, UCP-2 and UCP-3, whereas in plant mitochondria by PUMP and StUCP, all belonging to the gene family of mitochondrial carriers. UCP-1, and hypothetically UCP-3, serve mostly to provide nonshivering thermogenesis in brown adipose tissue and skeletal muscle, respectively. Fatty acid cycling was documented for UCP-1, PUMP and ADP/ATP carrier, and is predicted also for UCP-2 and UCP-3. UCP-1 mediates a purine nucleotide-sensitive uniport of monovalent unipolar anions, including anionic fatty acids. The return of protonated fatty acid leads to H+ uniport and uncoupling. UCP-2 is probably involved in the regulation of body weight and energy balance, in fever, and defense against generation of reactive oxygen species. PUMP has been discovered in potato tubers and immunologically detected in fruits and corn, whereas StUCP has been cloned and sequenced froma a potato gene library. PUMP is supposed to act in the termination of synthetic processes in mature fruits and during the climacteric respiratory rise.
我们假设脂肪酸诱导的解偶联作用于生物能量系统，以设定最佳效率并调节氧化磷酸化的偶联程度。解偶联源于脂肪酸循环，这是由几种系统发育上专门的蛋白质促成的，在较小程度上也由其他线粒体载体促成。有人提出，哺乳动物线粒体中的调节性解偶联是由解偶联蛋白UCP - 1、UCP - 2和UCP - 3提供的，而植物线粒体中的解偶联是由PUMP和StUCP提供的，它们都属于线粒体载体基因家族。UCP - 1，以及推测的UCP - 3，分别主要在棕色脂肪组织和骨骼肌中提供非颤抖性产热。已证明UCP - 1、PUMP和ADP/ATP载体存在脂肪酸循环，预计UCP - 2和UCP - 3也存在脂肪酸循环。UCP - 1介导对嘌呤核苷酸敏感的单价单极阴离子单向转运，包括阴离子脂肪酸。质子化脂肪酸的返回导致H⁺单向转运和解偶联。UCP - 2可能参与体重和能量平衡的调节、发热以及对活性氧生成的防御。PUMP已在马铃薯块茎中发现，并在果实和玉米中通过免疫检测到，而StUCP已从马铃薯基因文库中克隆并测序。PUMP被认为在成熟果实的合成过程终止以及呼吸跃变期间起作用。
