Ross Tilley Burn Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada.
University of Toronto, Toronto, Ontario M5S 1A1, Canada.
Metabolism. 2021 May;118:154733. doi: 10.1016/j.metabol.2021.154733. Epub 2021 Feb 23.
It is well-established that mitochondria are the powerhouses of the cell, producing adenosine triphosphate (ATP), the universal energy currency. However, the most significant strengths of the electron transport chain (ETC), its intricacy and efficiency, are also its greatest downfalls. A reliance on metal complexes (FeS clusters, hemes), lipid moities such as cardiolipin, and cofactors including alpha-lipoic acid and quinones render oxidative phosphorylation vulnerable to environmental toxins, intracellular reactive oxygen species (ROS) and fluctuations in diet. To that effect, it is of interest to note that temporal disruptions in ETC activity in most organisms are rarely fatal, and often a redundant number of failsafes are in place to permit continued ATP production when needed. Here, we highlight the metabolic reconfigurations discovered in organisms ranging from parasitic Entamoeba to bacteria such as pseudomonads and then complex eukaryotic systems that allow these species to adapt to and occasionally thrive in harsh environments. The overarching aim of this review is to demonstrate the plasticity of metabolic networks and recognize that in times of duress, life finds a way.
众所周知，线粒体是细胞的能量工厂，它们产生三磷酸腺苷（ATP），这是通用的能量货币。然而，电子传递链（ETC）最大的优势——其复杂性和效率——也是它最大的弱点。ETC 依赖于金属复合物（FeS 簇、血红素）、脂类部分（如心磷脂）以及辅助因子（如α-硫辛酸和醌），这使得氧化磷酸化易受到环境毒素、细胞内活性氧（ROS）和饮食波动的影响。值得注意的是，大多数生物体中线粒体电子传递链活性的短暂中断很少是致命的，而且通常有冗余的故障安全机制来确保在需要时继续产生 ATP。在这里，我们强调了从寄生性的内阿米巴到假单胞菌等细菌，再到复杂的真核生物系统中发现的代谢重排，这些物种能够适应甚至在恶劣环境中茁壮成长。本综述的总体目标是展示代谢网络的可塑性，并认识到在压力时期，生命总会找到出路。
