MEASURING THE RESPONSES OF THE MITOPHAGY PATHWAY TO TRANSIENT MITOCHONDRIAL STRESS AT THE LEVEL OF POLYUBIQUITIN AND PHOSPHO-POLYUBIQUITIN CHAIN FORMATION

Abstract

The PINK1:Parkin mitophagy pathway is a mitochondrial quality control system that functions to maintain the health and integrity of mitochondrial networks in somatic cells. Parkin proteins assemble polyubiquitin (pUb) chains on the surface of irretrievably damaged, depolarized mitochondria, and these chains are phosphorylated by PINK1 to create phospho-pUb (ppUb), a unique mitochondrial destruction signal. Here, we investigate the ability of the PINK1:Parkin pathway to discriminate between different levels and durations of mitochondrial stress by using biochemical techniques to study the recruitment, assembly, and persistence of PINK1 proteins, pUb, and ppUb to mitochondria under conditions of complete and transient mitochondrial depolarization.