PINK1

Serine/threonine-protein kinase which acts as a sensor of mitochondrial damage and protects against mitochondrial dysfunction during cellular stress. It phosphorylates mitochondrial proteins to coordinate mitochondrial quality control mechanisms that remove and replace dysfunctional mitochondrial components (PubMed:14607334, PubMed:15087508, PubMed:18443288, PubMed:18957282, PubMed:19229105, PubMed:19966284, PubMed:20404107, PubMed:20547144, PubMed:20798600, PubMed:22396657, PubMed:23620051, PubMed:23754282, PubMed:23933751, PubMed:24660806, PubMed:24751536, PubMed:24784582, PubMed:24896179, PubMed:24898855, PubMed:25527291, PubMed:32484300). Depending on the severity of mitochondrial damage, activity ranges from preventing apoptosis and stimulating mitochondrial biogenesis to eliminating severely damaged mitochondria via PINK1-PRKN-dependent mitophagy (PubMed:14607334, PubMed:15087508, PubMed:18443288, PubMed:19966284, PubMed:20404107, PubMed:20798600, PubMed:22396657, PubMed:23620051, PubMed:23933751, PubMed:24898855, PubMed:32047033, PubMed:32484300). When cellular stress results in irreversible mitochondrial damage, PINK1 accumulates at the outer mitochondrial membrane (OMM) where it phosphorylates pre-existing polyubiquitin chains at 'Ser-65', recruits PRKN from the cytosol to the OMM and activates PRKN by phosphorylation at 'Ser-65'; activated PRKN then ubiquinates VDAC1 and other OMM proteins to initiate mitophagy (PubMed:14607334, PubMed:15087508, PubMed:19966284, PubMed:20404107, PubMed:20798600, PubMed:23754282, PubMed:23933751, PubMed:24660806, PubMed:24751536, PubMed:24784582, PubMed:25474007, PubMed:25527291, PubMed:32047033). The PINK1-PRKN pathway also promotes fission of damaged mitochondria through phosphorylation and PRKN-dependent degradation of mitochondrial proteins involved in fission such as MFN2 (PubMed:18443288, PubMed:23620051, PubMed:24898855). This prevents the refusion of unhealthy mitochondria with the mitochondrial network or initiates mitochondrial fragmentation facilitating their later engulfment by autophagosomes (PubMed:18443288, PubMed:23620051). Also promotes mitochondrial fission independently of PRKN and ATG7-mediated mitophagy, via the phosphorylation and activation of DNM1L (PubMed:18443288, PubMed:32484300). Regulates motility of damaged mitochondria by promoting the ubiquitination and subsequent degradation of MIRO1 and MIRO2; in motor neurons, this likely inhibits mitochondrial intracellular anterograde transport along the axons which probably increases the chance of the mitochondria undergoing mitophagy in the soma (PubMed:22396657). Required for ubiquinone reduction by mitochondrial complex I by mediating phosphorylation of complex I subunit NDUFA10 (By similarity). Phosphorylates LETM1, positively regulating its mitochondrial calcium transport activity (PubMed:29123128).

Parkinson disease 6

PARK6

An early-onset form of Parkinson disease, a neurodegenerative disorder characterized by parkinsonian signs such as rigidity, resting tremor and bradykinesia. A subset of patients manifest additional symptoms including hyperreflexia, autonomic instability, dementia and psychiatric disturbances. Symptoms show diurnal fluctuation and can improve after sleep. PARK6 pathogenesis involves respiratory complex I deficiency causing mitochondrial depolarization and dysfunction. Inheritance is autosomal recessive.

None

The disease is caused by variants affecting the gene represented in this entry.

Proteolytically cleaved (PubMed:19229105, PubMed:22354088, PubMed:30733118). In healthy cells, the precursor is continuously imported into the inner mitochondrial membrane (IMM), where it is proteolytically cleaved by mitochondrial-processing peptidase (MPP) and then undergoes further proteolytic cleavage by PARL or AFG3L2 to give rise to the 52 kDa short form (PubMed:19229105, PubMed:22354088). The 52 kDa short form is then released into the cytosol where it rapidly undergoes proteasome-dependent degradation (PubMed:20404107). In unhealthy cells, when cellular stress conditions lead to the loss of mitochondrial membrane potential, mitochondrial import is impaired leading to the precursor accumulating on the outer mitochondrial membrane (OMM) (PubMed:20404107, PubMed:30733118). If accumulation at the OMM fails and it is imported into the depolarized mitochondria, it undergoes cleavage by the IMM protease OMA1, promoting its subsequent degradation by the proteasome (PubMed:30733118).

Autophosphorylated (PubMed:18957282, PubMed:20404107, PubMed:22910362). Loss of mitochondrial membrane potential results in the precursor accumulating on the outer mitochondrial membrane (OMM) where it is activated by autophosphorylation (PubMed:18957282, PubMed:20404107, PubMed:22910362). Autophosphorylation at Ser-228 and Ser-402 is sufficient and essential for selective recruitment of PRKN to depolarized mitochondria, via PINK1-dependent phosphorylation of ubiquitin and maybe PRKN (PubMed:18957282, PubMed:22910362).

Belongs to the protein kinase superfamily. Ser/Thr protein kinase family.

Highly expressed in heart, skeletal muscle and testis, and at lower levels in brain, placenta, liver, kidney, pancreas, prostate, ovary and small intestine. Present in the embryonic testis from an early stage of development.

• Mitochondrion outer membrane
• Single-pass membrane protein
• Mitochondrion inner membrane
• Single-pass membrane protein
• Cytoplasm
• Cytosol
• Localizes mostly in mitochondrion and the two smaller proteolytic processed fragments localize mainly in cytosol (PubMed:19229105). Upon mitochondrial membrane depolarization following damage, PINK1 import into the mitochondria is arrested, which induces its accumulation in the outer mitochondrial membrane, where it acquires kinase activity (PubMed:18957282).

BRPK, PTEN-induced putative kinase protein 1, PINK1

• entrezGene:65018
• ncbi:14165272
• omim:608309
• swissprot:Q9BXM7

Proteins

Neuroscience

62769Da