The Deubiquitinating Enzyme UBPY Is Required for Lysosomal Biogenesis and Productive Autophagy in Drosophila

PLoS One. 2015 Nov 16;10(11):e0143078. doi: 10.1371/journal.pone.0143078. eCollection 2015.

Abstract

Autophagy is a catabolic process that delivers cytoplasmic components to the lysosomes. Protein modification by ubiquitination is involved in this pathway: it regulates the stability of autophagy regulators such as BECLIN-1 and it also functions as a tag targeting specific substrates to autophagosomes. In order to identify deubiquitinating enzymes (DUBs) involved in autophagy, we have performed a genetic screen in the Drosophila larval fat body. This screen identified Uch-L3, Usp45, Usp12 and Ubpy. In this paper, we show that Ubpy loss of function results in the accumulation of autophagosomes due to a blockade of the autophagy flux. Furthermore, analysis by electron and confocal microscopy of Ubpy-depleted fat body cells revealed altered lysosomal morphology, indicating that Ubpy inactivation affects lysosomal maintenance and/or biogenesis. Lastly, we have shown that shRNA mediated inactivation of UBPY in HeLa cells affects autophagy in a different way: in UBPY-depleted HeLa cells autophagy is deregulated.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autophagy*
  • Biocatalysis
  • Drosophila Proteins / metabolism*
  • Drosophila melanogaster / cytology*
  • Drosophila melanogaster / enzymology*
  • Drosophila melanogaster / ultrastructure
  • Endopeptidases / metabolism*
  • Endosomal Sorting Complexes Required for Transport / metabolism*
  • Gene Silencing
  • Genetic Testing
  • HeLa Cells
  • Humans
  • Lysosomes / metabolism*
  • Mutant Proteins / metabolism
  • Organelle Biogenesis*
  • Ubiquitin Thiolesterase / metabolism*
  • Ubiquitin-Specific Proteases / metabolism*

Substances

  • Drosophila Proteins
  • Endosomal Sorting Complexes Required for Transport
  • Mutant Proteins
  • Endopeptidases
  • USP8 protein, Drosophila
  • USP8 protein, human
  • Ubiquitin Thiolesterase
  • Ubiquitin-Specific Proteases

Grant support

This work used the platforms of the Grenoble Instruct centre (ISBG; UMS 3518 CNRS-CEA-UJF-EMBL) with support from FRISBI (ANR-10-INSB-05-02) and GRAL (ANR-10-LABX-49-01) within the Grenoble Partnership for Structural Biology (PSB). This work was supported by the FINOVI foundation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.