Dipartimento di Scienze della Vita, Seconda Università degli Studi di Napoli, Caserta, Italy.
Biofactors. 2009 Sep-Oct;35(5):417-28. doi: 10.1002/biof.54.
Since their discovery, uncoupling proteins have aroused great interest due to the crucial importance of energy-dissipating system for cellular physiology. The uncoupling effect and the physiological role of UCP1 (the first-described uncoupling protein) are well established. However, the reactions catalyzed by UCP1 homologues (UCPs), and their physiological roles are still under debate, with the literature containing contrasting results. Current hypothesis propose several physiological functions for novel UCPs, such as: (i) attenuation of reactive oxygen species production and protection against oxidative damage, (ii) thermogenic function, although UCPs do not generally seem to affect thermogenesis, UCP3 can be thermogenic under certain conditions, (iii) involvement in fatty acid handling and/or transport, although recent experimental evidence argues against the previously hypothesized role for UCPs in the export of fatty acid anions, (iv) fatty acid hydroperoxide export, although this function, due to the paucity of the experimental evidence, remains hypothetical, (v) Ca(2+) uptake, although results for and against a role in Ca(2+) uptake are still emerging, (vi) a signaling role in pancreatic beta cells, where it attenuates glucose-induced insulin secretion. From the above, it is evident that more research will be needed to establish universally accepted functions for UCPs.
自发现以来，解偶联蛋白因其对细胞生理学中能量耗散系统的重要性而引起了极大的兴趣。解偶联作用和 UCP1（第一个描述的解偶联蛋白）的生理作用已经得到很好的证实。然而，UCP1 同源物（UCPs）催化的反应及其生理作用仍存在争议，文献中包含相互矛盾的结果。目前的假设为新的 UCPs 提出了几种生理功能，例如：（i）减少活性氧的产生并防止氧化损伤，（ii）产热功能，尽管 UCPs 通常似乎不会影响产热，UCP3 在某些条件下可以产热，（iii）参与脂肪酸处理和/或运输，尽管最近的实验证据反对以前假设的 UCPs 在脂肪酸阴离子输出中的作用，（iv）脂肪酸氢过氧化物输出，尽管由于实验证据不足，此功能仍假设存在，（v）Ca2+摄取，尽管支持和反对 UCPs 在 Ca2+摄取中作用的结果仍在出现，（vi）在胰岛β细胞中的信号作用，其中它减弱葡萄糖诱导的胰岛素分泌。综上所述，显然需要更多的研究来确定 UCPs 的普遍接受的功能。
