Bcl-2-associated athanogene 5 (BAG5) regulates Parkin-dependent mitophagy and cell death

Cell Death Dis. 2019 Dec 2;10(12):907. doi: 10.1038/s41419-019-2132-x.

Abstract

As pathogenic Parkin mutations result in the defective clearance of damaged mitochondria, Parkin-dependent mitophagy is thought to be protective against the dopaminergic neurodegeneration observed in Parkinson's disease. Recent studies, however, have demonstrated that Parkin can promote cell death in the context of severe mitochondrial damage by degrading the pro-survival Bcl-2 family member, Mcl-1. Therefore, Parkin may act as a 'switch' that can shift the balance between protective or pro-death pathways depending on the degree of mitochondrial damage. Here, we report that the Parkin interacting protein, Bcl-2-associated athanogene 5 (BAG5), impairs mitophagy by suppressing Parkin recruitment to damaged mitochondria and reducing the movement of damaged mitochondria into the lysosomes. BAG5 also enhanced Parkin-mediated Mcl-1 degradation and cell death following severe mitochondrial insult. These results suggest that BAG5 may regulate the bi-modal activity of Parkin, promoting cell death by suppressing Parkin-dependent mitophagy and enhancing Parkin-mediated Mcl-1 degradation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / metabolism*
  • Apoptosis* / drug effects
  • Carbonyl Cyanide m-Chlorophenyl Hydrazone / pharmacology
  • Caspase 3 / metabolism
  • Cell Line, Tumor
  • Gene Knockdown Techniques
  • HEK293 Cells
  • Humans
  • Membrane Potential, Mitochondrial / drug effects
  • Mitochondria / drug effects
  • Mitochondria / metabolism
  • Mitophagy* / drug effects
  • Models, Biological
  • Myeloid Cell Leukemia Sequence 1 Protein / metabolism
  • Poly(ADP-ribose) Polymerases / metabolism
  • Protein Stability / drug effects
  • Proteolysis / drug effects
  • Ubiquitin-Protein Ligases / metabolism*

Substances

  • Adaptor Proteins, Signal Transducing
  • BAG5 protein, human
  • MCL1 protein, human
  • Myeloid Cell Leukemia Sequence 1 Protein
  • Carbonyl Cyanide m-Chlorophenyl Hydrazone
  • Ubiquitin-Protein Ligases
  • parkin protein
  • Poly(ADP-ribose) Polymerases
  • Caspase 3

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