Isolation of Rab5-positive endosomes reveals a new mitochondrial degradation pathway utilized by BNIP3 and Parkin

Small GTPases. 2020 Jan;11(1):69-76. doi: 10.1080/21541248.2017.1342749. Epub 2017 Sep 18.


Degradation of mitochondria is an important cellular quality control mechanism mediated by two distinct pathways: one involving Parkin-mediated ubiquitination and the other dependent on mitophagy receptors. It is known that mitochondria are degraded by the autophagy pathway; however, we recently reported that the small GTPase Rab5 and early endosomes also participate in Parkin-mediated mitochondrial clearance. Here, we have developed a protocol to isolate Rab5-positive vesicles from cells for proteomics analysis and provide additional data confirming that mitophagy regulators and mitochondrial proteins are present in these vesicles. We also demonstrate that the mitophagy receptor BNIP3 utilizes the Rab5-endosomal pathway to clear mitochondria in cells. These findings indicate that a redundancy exists in the downstream degradation pathways to ensure efficient mitochondrial clearance.

Keywords: BNIP3; Parkin; Rab5; autophagy; endosomes; mitochondria; mitophagy.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Endosomes / metabolism*
  • Membrane Proteins / metabolism*
  • Mice
  • Mitochondrial Proteins / metabolism*
  • Mitophagy*
  • Ubiquitin-Protein Ligases / metabolism*
  • rab5 GTP-Binding Proteins / metabolism*


  • BNip3 protein, mouse
  • Membrane Proteins
  • Mitochondrial Proteins
  • Ubiquitin-Protein Ligases
  • parkin protein
  • rab5 GTP-Binding Proteins