Fig. 1

PINK1-mediated intramitochondrial signaling in healthy mitochondria. PINK1 is imported into healthy mitochondria through the TOM and TIM complexes and is then cleaved sequentially by mitochondrial processing peptidase (MPP) and PARL to generate a processed form of PINK1 that resides in the intermembrane space. There, PINK1 can phosphorylate mitochondrial chaperone TRAP1 and perhaps also other substrates to regulate the activities of polarized mitochondria, such as respiration and redox control