USP14 inhibits ER-associated degradation via interaction with IRE1alpha

Biochem Biophys Res Commun. 2009 Feb 20;379(4):995-1000. doi: 10.1016/j.bbrc.2008.12.182. Epub 2009 Jan 9.

Abstract

Accumulation of unfolded proteins within the endoplasmic reticulum (ER) lumen induces ER stress. Eukaryotic cells possess the ER quality control systems, the unfolded protein response (UPR), to adapt to ER stress. IRE1alpha is one of the ER stress receptors and mediates the UPR. Here, we identified ubiquitin specific protease (USP) 14 as a binding partner of IRE1alpha. USP14 interacted with the cytoplasmic region of IRE1alpha, and the endogenous interaction between USP14 and IRE1alpha was inhibited by ER stress. Overexpression of USP14 inhibited the ER-associated degradation (ERAD) pathway, and USP14 depletion by small interfering RNA effectively activated ERAD. These findings suggest that USP14 is a novel player in the UPR by serving as a physiological inhibitor of ERAD under the non-stressed condition.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Endoplasmic Reticulum / enzymology*
  • Endoribonucleases / genetics
  • Endoribonucleases / metabolism*
  • HeLa Cells
  • Humans
  • Membrane Proteins / metabolism*
  • Protein Folding
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism*
  • Two-Hybrid System Techniques
  • Ubiquitin Thiolesterase / genetics
  • Ubiquitin Thiolesterase / metabolism*

Substances

  • Membrane Proteins
  • USP14 protein, human
  • ERN1 protein, human
  • Protein-Serine-Threonine Kinases
  • Endoribonucleases
  • Ubiquitin Thiolesterase