Signaling pathway of mitochondrial stress

Mitochondria, vital organelles, produce ATP efficiently for energy homeostasis via aerobic respiration and play a key role in tricarboxylic acid cycle, fatty acid oxidation, regulating of calcium homeostasis. Mitochondria are principal regulators of cell signaling via production of reactive oxygen species. Under various exogenous and/or endogenous stresses, mitochondria have the ability to adapt to changing environmental conditions, termed mitochondrial stress. Mitochondrial stress reconstructs mitochondrial homeostasis through integrated signaling termed the mitochondrial unfolded protein response (UPR_mt). The mitochondrial UPR_mt is a response of the cell to relieve mitochondrial damage and respond to proteotoxic stress specifically in mitochondria. Meanwhile, the mitochondrial UPR_mt can sustain proteostasis and maintain overall cellular homeostasis. This review highlights the complex molecular mechanisms of the mitochondrial UPR_mt.