Peroxisomal protein PEX13 functions in selective autophagy

EMBO Rep. 2017 Jan;18(1):48-60. doi: 10.15252/embr.201642443. Epub 2016 Nov 8.

Abstract

PEX13 is an integral membrane protein on the peroxisome that regulates peroxisomal matrix protein import during peroxisome biogenesis. Mutations in PEX13 and other peroxin proteins are associated with Zellweger syndrome spectrum (ZSS) disorders, a subtype of peroxisome biogenesis disorder characterized by prominent neurological, hepatic, and renal abnormalities leading to neonatal death. The lack of functional peroxisomes in ZSS patients is widely accepted as the underlying cause of disease; however, our understanding of disease pathogenesis is still incomplete. Here, we demonstrate that PEX13 is required for selective autophagy of Sindbis virus (virophagy) and of damaged mitochondria (mitophagy) and that disease-associated PEX13 mutants I326T and W313G are defective in mitophagy. The mitophagy function of PEX13 is shared with another peroxin family member PEX3, but not with two other peroxins, PEX14 and PEX19, which are required for general autophagy. Together, our results demonstrate that PEX13 is required for selective autophagy, and suggest that dysregulation of PEX13-mediated mitophagy may contribute to ZSS pathogenesis.

Keywords: PEX13; Zellweger syndrome; autophagy; mitophagy; virophagy.

MeSH terms

  • Animals
  • Autophagy*
  • Cell Line
  • Gene Knockdown Techniques
  • Humans
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mice
  • Mice, Transgenic
  • Mitochondria / metabolism
  • Mitophagy
  • Peroxisomes / metabolism
  • Protein Binding
  • Protein Transport
  • RNA, Small Interfering / genetics
  • Sindbis Virus / physiology
  • Ubiquitin-Protein Ligases / metabolism
  • Zellweger Syndrome / genetics
  • Zellweger Syndrome / metabolism

Substances

  • Membrane Proteins
  • PEX13 protein, human
  • RNA, Small Interfering
  • Ubiquitin-Protein Ligases
  • parkin protein