Figure 3. Mitochondrial ROS regulate the cellular response to hypoxia.
Hypoxia leads to an induction in the production of mitochondrial ROS. These ROS inhibit the activity of PHD2, leading to stabilization of HIFα subunits (blue) and transcriptional activation. Mitochondrial ROS generated during hypoxia regulate increases in cellular calcium uptake and contraction of pulmonary arteries. Mitochondrial ROS also lead to activation of AMPK, allowing increased cellular energy conservation. AMPK phosphorylates the α-subunit (peach) of the Na/K ATPase leading to endocytosis.