Format

Send to

Choose Destination
Autophagy. 2014 May;10(5):835-45. doi: 10.4161/auto.28259. Epub 2014 Mar 18.

Deficiency of the exportomer components Pex1, Pex6, and Pex15 causes enhanced pexophagy in Saccharomyces cerevisiae.

Author information

1
Department of Molecular Biology and Biotechnology; University of Sheffield, Western Bank; Sheffield, UK.

Abstract

Turnover of damaged, dysfunctional, or excess organelles is critical to cellular homeostasis. We screened mutants disturbed in peroxisomal protein import, and found that a deficiency in the exportomer subunits Pex1, Pex6, and Pex15 results in enhanced turnover of peroxisomal membrane structures compared with other mutants. Strikingly, almost all peroxisomal membranes were associated with phagophore assembly sites in pex1Δ atg1Δ cells. Degradation depended on Atg11 and the pexophagy receptor Atg36, which mediates degradation of superfluous peroxisomes. Mutants of PEX1, PEX6, and PEX15 accumulate ubiquitinated receptors at the peroxisomal membrane. This accumulation has been suggested to trigger pexophagy in mammalian cells. We show by genetic analysis that preventing this accumulation does not abolish pexophagy in Saccharomyces cerevisiae. We find Atg36 is modified in pex1Δ cells even when Atg11 binding is prevented, suggesting Atg36 modification is an early event in the degradation of dysfunctional peroxisomal structures in pex1Δ cells via pexophagy.

KEYWORDS:

Atg36; Pex1; Pex6; exportomer; peroxin; peroxisome; pexophagy; selective autophagy

PMID:
24657987
PMCID:
PMC5119063
DOI:
10.4161/auto.28259
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Taylor & Francis Icon for PubMed Central
Loading ...
Support Center