Investigating the mechanisms of Parkin-mediated mitophagy

Determining how cells maintain homeostasis in times of stress is vital to understanding a wide-range of disorders, from neurodegenerative diseases to cardiomyopathies. Autophagy is a catabolic cytosolic pathway that functions to degrade damaged organelles and misfolded proteins, while providing a protective mechanism under stress. Mitophagy, the selective autophagic pathway for mitochondria limits oxidative stress by degrading damaged mitochondria through a mechanism involving ubiquitylation and recruitment of autophagic machinery. One mechanism of mitophagy, which is dysregulated during Parkinson’s disease, is the PINK1-parkin pathway.

We will identify and characterise regulators of parkin which facilitate its recruitment to mitochondria. We will focus on an adaptor protein complex Tollip-Tom1, which has been suggested to be linked to this process and which functions to regulate trafficking along both the endolysosomal and autophagic pathways. We will use microscopic imaging and biochemical assays to dissect the spatiotemporal regulation of parkin-mediated mitophagy after targeted loss of function of Tom1 and Tollip. In addition, we will use CRISPR-Cas9 technology, coupled to cDNA reconstitution experiments, and primary patient-derived fibroblasts to understand mechanisms of parkin recruitment after mitochondrial damage.

The outcomes will provide crucial mechanisms that illustrate how cells regulate PINK1-parkin mediated mitophagy to maintain their health.