Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Cell. 2006 Jul 28;126(2):349-59.

A luminal surveillance complex that selects misfolded glycoproteins for ER-associated degradation.

Author information

  • 1Howard Hughes Medical Institute, Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158, USA.

Abstract

How the ER-associated degradation (ERAD) machinery accurately identifies terminally misfolded proteins is poorly understood. For luminal ERAD substrates, this recognition depends on their folding and glycosylation status as well as on the conserved ER lectin Yos9p. Here we show that Yos9p is part of a stable complex that organizes key components of ERAD machinery on both sides of the ER membrane, including the transmembrane ubiquitin ligase Hrd1p. We further demonstrate that Yos9p, together with Kar2p and Hrd3p, forms a luminal surveillance complex that both recruits nonnative proteins to the core ERAD machinery and assists a distinct sugar-dependent step necessary to commit substrates for degradation. When Hrd1p is uncoupled from the Yos9p surveillance complex, degradation can occur independently of the requirement for glycosylation. Thus, Yos9p/Kar2p/Hrd3p acts as a gatekeeper, ensuring correct identification of terminally misfolded proteins by recruiting misfolded forms to the ERAD machinery, contributing to the interrogation of substrate sugar status, and preventing glycosylation-independent degradation.

Comment in

PMID:
16873065
[PubMed - indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Write to the Help Desk