PKA Regulates PINK1 Stability and Parkin Recruitment to Damaged Mitochondria through Phosphorylation of MIC60

Mol Cell. 2016 May 5;62(3):371-384. doi: 10.1016/j.molcel.2016.03.037.


A mitochondrial kinase, PTEN-induced putative kinase 1 (PINK1), selectively recruits the ubiquitin ligase Parkin to damaged mitochondria, which modifies mitochondria by polyubiquitination, leading to mitochondrial autophagy. Here, we report that treatment with an adenylate cyclase agonist or expression of protein kinase A (PKA) impairs Parkin recruitment to damaged mitochondria and decreases PINK1 protein levels. We identified a mitochondrial membrane protein, MIC60 (also known as mitofilin), as a PKA substrate. Mutational and mass spectrometric analyses revealed that the Ser528 residue of MIC60 undergoes PKA-dependent phosphorylation. MIC60 transiently interacts with PINK1, and MIC60 downregulation leads to a reduction in PINK1 and mislocalization of Parkin. Phosphorylation-mimic mutants of MIC60 fail to restore the defect in Parkin recruitment in MIC60-knocked down cells, whereas a phosphorylation-deficient MIC60 mutant facilitates the mitochondrial localization of Parkin. Our findings indicate that PKA-mediated phosphorylation of MIC60 negatively regulates mitochondrial clearance that is initiated by PINK1 and Parkin.

MeSH terms

  • Cyclic AMP-Dependent Protein Kinases / metabolism*
  • HEK293 Cells
  • HeLa Cells
  • Humans
  • Membrane Proteins / metabolism
  • Mitochondria / enzymology*
  • Mitochondria / ultrastructure
  • Mitochondrial Membranes / enzymology
  • Mitochondrial Membranes / ultrastructure
  • Mitochondrial Proteins / genetics
  • Mitochondrial Proteins / metabolism*
  • Muscle Proteins / genetics
  • Muscle Proteins / metabolism*
  • Mutation
  • Phosphorylation
  • Protein Kinases / genetics
  • Protein Kinases / metabolism*
  • Protein Stability
  • Protein Transport
  • RNA Interference
  • Signal Transduction
  • Time Factors
  • Transfection
  • Ubiquitin-Protein Ligases / genetics
  • Ubiquitin-Protein Ligases / metabolism*


  • CHCHD3 protein, human
  • IMMT protein, human
  • Membrane Proteins
  • Mitochondrial Proteins
  • Muscle Proteins
  • Ubiquitin-Protein Ligases
  • parkin protein
  • Protein Kinases
  • PTEN-induced putative kinase
  • Cyclic AMP-Dependent Protein Kinases