The biological function of plant mitochondrial uncoupling proteins (pUCPs) has been a matter of considerable controversy. For example, the pUCP capacity to uncouple respiration from ATP synthesis in vivo has never been fully acknowledged, in contrast to the mammalian UCP1 (mUCP1) role in uncoupling respiration-mediated thermogenesis. Interestingly, both pUCPs and mUCPs have been associated with stress response and metabolic perturbations. Some central questions that remain are how pUCPs and mUCPs compare in biochemical properties, molecular structure and cell biology under physiological and metabolically perturbed conditions. This review takes advantage of the large amount of data available for mUCPs to review the biochemical properties, 3D structure models and potential physiological roles of pUCPs during plant development and response to stress. The biochemical properties and structure of pUCPs are revisited in light of the recent findings that pUCPs catalyse the transport of metabolites across the mitochondrial inner membrane and the resolved mUCP2 protein structure. Additionally, transcriptional regulation and co-expression networks of UCP orthologues across species are analysed, taking advantage of publicly available curated experimental datasets. Taking these together, the biological roles of pUCPs are analysed in the context of their potential roles in thermogenesis, ROS production, cell signalling and the regulation of plant cellular bioenergetics. Finally, pUCPs biological function is discussed in the context of their potential role in protecting against environmental stresses.

中文翻译：

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植物生物能量学和应激反应中的线粒体解偶联蛋白依赖性信号传导

植物线粒体解偶联蛋白 (pUCPs) 的生物学功能一直存在相当大的争议。例如，与哺乳动物 UCP1 (mUCP1) 在解偶联呼吸介导的产热中的作用相比，pUCP 将呼吸与体内 ATP 合成解偶联的能力从未得到充分承认。有趣的是，pUCPs 和 mUCPs 都与应激反应和代谢紊乱有关。仍然存在的一些核心问题是 pUCPs 和 mUCPs 在生理和代谢扰动条件下如何比较生化特性、分子结构和细胞生物学。本综述利用 mUCPs 的大量可用数据来回顾 pUCPs 在植物发育和应激反应过程中的生化特性、3D 结构模型和潜在的生理作用。根据最近发现 pUCPs 催化代谢物跨线粒体内膜转运和解析的 mUCP2 蛋白质结构，重新审视 pUCPs 的生化特性和结构。此外，利用公开可用的精选实验数据集，分析了跨物种的 UCP 直向同源物的转录调控和共表达网络。将这些放在一起，在 pU​​CPs 在产热、ROS 产生、细胞信号传导和植物细胞生物能学调节中的潜在作用的背景下分析了 pUCP 的生物学作用。最后，讨论了 pUCPs 的生物学功能，讨论了它们在抵御环境压力方面的潜在作用。