<unk> is a 465-amino acid residue E3 ubiquitin ligase, a protein that in humans and mice is encoded by the PARK2 gene.<unk> plays a critical role in ubiquitination – the process whereby molecules are covalently labelled with ubiquitin (Ub) and directed towards degradation in proteasomes or lysosomes. Ubiquitination involves the sequential action of three enzymes. First, an E1 ubiquitin-activating enzyme binds to inactive Ub in eukaryotic cells via a thioester bond and mobilises it in an ATP-dependent process. Ub is then transferred to an E2 ubiquitin-conjugating enzyme before being conjugated to the target protein via an E3 ubiquitin ligase. There exists a multitude of E3 ligases, which differ in structure and substrate specificity to allow selective targeting of proteins to intracellular degradation. In particular,<unk> recognises proteins on the outer membrane of mitochondria upon cellular insult and mediates the clearance of damaged mitochondria via autophagy and proteasomal mechanisms.<unk> also enhances cell survival by suppressing both mitochondria-dependent and -independent apoptosis. Mutations are associated with mitochondrial dysfunction, leading to neuronal death in<unk> on’s disease and aberrant metabolism in tumourigenesis.
Parkin 
Peripherin
CEPP
Tetraspanin
Dystrophin
Alpha-synuclein
Huntingtin-interacting protein 1
MSin3 interaction domain