Gladstone Institute of Neurological Disease, San Francisco, CA, 94158, USA.
Department of Radiation Oncology, University of California, San Francisco, CA, 94158, USA.
Nat Commun. 2020 Aug 28;11(1):4319. doi: 10.1038/s41467-020-18084-6.
Disrupted energy metabolism drives cell dysfunction and disease, but approaches to increase or preserve ATP are lacking. To generate a comprehensive metabolic map of genes and pathways that regulate cellular ATP-the ATPome-we conducted a genome-wide CRISPR interference/activation screen integrated with an ATP biosensor. We show that ATP level is modulated by distinct mechanisms that promote energy production or inhibit consumption. In our system HK2 is the greatest ATP consumer, indicating energy failure may not be a general deficiency in producing ATP, but rather failure to recoup the ATP cost of glycolysis and diversion of glucose metabolites to the pentose phosphate pathway. We identify systems-level reciprocal inhibition between the HIF1 pathway and mitochondria; glycolysis-promoting enzymes inhibit respiration even when there is no glycolytic ATP production, and vice versa. Consequently, suppressing alternative metabolism modes paradoxically increases energy levels under substrate restriction. This work reveals mechanisms of metabolic control, and identifies therapeutic targets to correct energy failure.
能量代谢紊乱会导致细胞功能障碍和疾病，但目前缺乏增加或维持 ATP 的方法。为了生成一个全面的代谢图谱，以了解调节细胞内 ATP（即 ATP 组）的基因和途径，我们进行了一项全基因组 CRISPR 干扰/激活筛选实验，该实验与一个 ATP 生物传感器相结合。我们发现，ATP 水平受到不同机制的调节，这些机制可以促进能量产生或抑制能量消耗。在我们的系统中，HK2 是最大的 ATP 消耗者，这表明能量衰竭可能不是产生 ATP 的普遍缺陷，而是无法弥补糖酵解产生的 ATP 成本，以及葡萄糖代谢物向磷酸戊糖途径的转移。我们发现 HIF1 途径和线粒体之间存在系统水平的相互抑制；即使没有糖酵解 ATP 产生，促进糖酵解的酶也会抑制呼吸，反之亦然。因此，在底物限制下，抑制替代代谢模式会出人意料地增加能量水平。这项工作揭示了代谢控制的机制，并确定了治疗靶点以纠正能量衰竭。
