Helmholtz Gemeinschaft

Search
Browse
Statistics
Feeds

Usa1 functions as a scaffold of the HRD-ubiquitin ligase

Official URL:https://doi.org/10.1016/j.molcel.2009.10.015
PubMed:View item in PubMed
Creators Name:Horn, S.C. and Hanna, J. and Hirsch, C. and Volkwein, C. and Schuetz, A. and Heinemann, U. and Sommer, T. and Jarosch, E.
Journal Title:Molecular Cell
Journal Abbreviation:Mol Cell
Volume:36
Number:5
Page Range:782-793
Date:11 December 2009
Keywords:Fungal Proteins, Protein Interaction Mapping, Ubiquitin-Protein Ligases, Yeasts
Abstract:Protein quality control in the endoplasmic reticulum is of central importance for cellular homeostasis in eukaryotes. Crucial for this process is the HRD-ubiquitin ligase (HMG-CoA reductase degradation), which singles out terminally misfolded proteins and routes them for degradation to cytoplasmic 26S-proteasomes. Certain functions of this enzyme complex are allocated to defined subunits. However, it remains unclear how these components act in a concerted manner. Here, we show that Usa1 functions as a major scaffold protein of the HRD-ligase. For the turnover of soluble substrates, Der1 binding to the C terminus of Usa1 is required. The N terminus of Usa1 associates with Hrd1 and thus bridges Der1 to Hrd1. Strikingly, the Usa1 N terminus also induces oligomerization of the HRD complex, which is an exclusive prerequisite for the degradation of membrane proteins. Our data demonstrate that scaffold proteins are required to adapt ubiquitin ligase activities toward different classes of substrates.
ISSN:1097-2765
Publisher:Cell Press (U.S.A.)
Item Type:Article

Repository Staff Only: item control page

Open Access
MDC Library