PTEN-induced kinase 1 and E3 ubiquitin-protein ligase parkin pathway (PINK1-Parkin)

The PTEN-induced kinase 1 (PINK1) and E3 ubiquitin-protein ligase parkin (PRKN) pathway is the central mechanism governing mitochondrial quality control through a process known as mitophagy (UniProt Q9BXM7, O60260). Under physiological conditions, PINK1 is imported into healthy mitochondria and rapidly degraded; however, when mitochondria become damaged or depolarized, PINK1 stabilizes on the outer mitochondrial membrane where it phosphorylates both ubiquitin and Parkin (PMID: 24751536). This phosphorylation event activates Parkin's E3 ligase activity, leading to the dense ubiquitination of mitochondrial surface proteins and the subsequent recruitment of autophagic receptors to engulf the organelle for lysosomal degradation (PMID: 21677679). Mutations in either PINK1 or Parkin are a primary cause of autosomal recessive early-onset Parkinson's disease, as the failure to clear dysfunctional mitochondria leads to oxidative stress and dopaminergic neuronal death (PMID: 15064450). Therapeutic development focuses on small-molecule activators of PINK1, such as MTK-458, or inhibitors of the deubiquitinating enzyme USP30, which acts as a negative regulator of the pathway by removing the ubiquitin tags added by Parkin (PMID: 25621951). Beyond neurodegeneration, the pathway is increasingly investigated for its role in protecting against cardiac ischemia and metabolic disorders.

Other names

PINK1-PRKN pathwayPINK1-Parkin mediated mitophagyPARK6-PARK2 axisMitochondrial quality control pathway

Activation of PINK1 kinase activity or Parkin E3 ligase activity to promote the clearance of damaged mitochondria; or inhibition of deubiquitinating enzymes like USP30 to enhance the mitophagy signal.