AMPK Maintains Cellular Metabolic Homeostasis through Regulation of Mitochondrial Reactive Oxygen Species

Publication date: 3 October 2017
Source:Cell Reports, Volume 21, Issue 1
Author(s): Rebecca C. Rabinovitch, Bozena Samborska, Brandon Faubert, Eric H. Ma, Simon-Pierre Gravel, Sylvia Andrzejewski, Thomas C. Raissi, Arnim Pause, Julie St.-Pierre, Russell G. Jones
Reactive oxygen species (ROS) are continuously produced as a by-product of mitochondrial metabolism and eliminated via antioxidant systems. Regulation of mitochondrially produced ROS is required for proper cellular function, adaptation to metabolic stress, and bypassing cellular senescence. Here, we report non-canonical regulation of the cellular energy sensor AMP-activated protein kinase (AMPK) by mitochondrial ROS (mROS) that functions to maintain cellular metabolic homeostasis. We demonstrate that mitochondrial ROS are a physiological activator of AMPK and that AMPK activation triggers a PGC-1α-dependent antioxidant response that limits mitochondrial ROS production. Cells lacking AMPK activity display increased mitochondrial ROS levels and undergo premature senescence. Finally, we show that AMPK-PGC-1α-dependent control of mitochondrial ROS regulates HIF-1α stabilization and that mitochondrial ROS promote the Warburg effect in cells lacking AMPK signaling. These data highlight a key function for AMPK in sensing and resolving mitochondrial ROS for stress resistance and maintaining cellular metabolic balance.

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Teaser

AMP-activated protein kinase (AMPK) regulates cellular metabolic balance in response to energy stress. This work by Rabinovitch et al. demonstrates that mitochondrial reactive oxygen species (mROS) are a physiological activator of AMPK and that AMPK couples mROS to an antioxidant program that regulates mitochondrial homeostasis and cellular metabolic balance.


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