Autophagy is an intracellular degradation process of cytosolic materials and damaged organelles. Researchers at Ubiquitin Project of TMIMS have been studying the molecular mechanism of mitophagy, the selective autophagy process to eliminate damaged mitochondria. PINK1 (a serine/threonine kinase) and Parkin (an ubiquitin ligating enzyme: E3) work together to ubiquitylate the outer membrane proteins of damaged mitochondria, then ubiquitin chains are recognized as signals for autophagy degradation. Dysfunction of mitophagy causes a decrease in mitochondrial quality with overproduction of ROS, and is linked to neurodegenerative diseases like Parkinson's disease.