JAMP optimizes ERAD to protect cells from unfolded proteins

Mol Biol Cell. 2008 Nov;19(11):5019-28. doi: 10.1091/mbc.e08-08-0839. Epub 2008 Sep 10.

Abstract

Clearance of misfolded proteins from the ER is central for maintenance of cellular homeostasis. This process requires coordinated recognition, ER-cytosol translocation, and finally ubiquitination-dependent proteasomal degradation. Here, we identify an ER resident seven-transmembrane protein (JAMP) that links ER chaperones, channel proteins, ubiquitin ligases, and 26S proteasome subunits, thereby optimizing degradation of misfolded proteins. Elevated JAMP expression promotes localization of proteasomes at the ER, with a concomitant effect on degradation of specific ER-resident misfolded proteins, whereas inhibiting JAMP promotes the opposite response. Correspondingly, a jamp-1 deleted Caenorhabditis elegans strain exhibits hypersensitivity to ER stress and increased UPR. Using biochemical and genetic approaches, we identify JAMP as important component for coordinated clearance of misfolded proteins from the ER.

Publication types

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

MeSH terms

  • Animals
  • Caenorhabditis elegans / metabolism
  • Carrier Proteins / metabolism
  • Endoplasmic Reticulum / metabolism*
  • Endoplasmic Reticulum / pathology
  • HeLa Cells
  • Humans
  • Membrane Glycoproteins / deficiency
  • Membrane Glycoproteins / metabolism*
  • Mice
  • Multiprotein Complexes / metabolism
  • Proteasome Endopeptidase Complex / metabolism
  • Protein Folding*
  • Protein Processing, Post-Translational*
  • Protein Subunits / metabolism
  • Protein Transport

Substances

  • Carrier Proteins
  • JAMP protein, mouse
  • Membrane Glycoproteins
  • Multiprotein Complexes
  • Protein Subunits
  • Proteasome Endopeptidase Complex