Structural basis for the interaction between human Npl4 and Npl4-binding motif of human Ufd1

Structure. 2022 Nov 3;30(11):1530-1537.e3. doi: 10.1016/j.str.2022.08.005. Epub 2022 Sep 9.

Abstract

The heterodimer of human ubiquitin fusion degradation 1 (hUfd1) and human nuclear protein localization 4 (hNpl4) is a major cofactor of human p97 adenosine triphosphatase (ATPase). The p97-Ufd1-Npl4 complex translocates the ubiquitin-conjugated proteins from the endoplasmic reticulum membrane to the cytoplasm. Ubiquitinated proteins are then degraded by the proteasome. The structures of Npl4 and Ufd1-Npl4 (UN) complex in Saccharomyces cerevisiae have been recently reported; however, the structures of hNpl4 and the human UN complex remain unknown. Here, we report the crystal structures of the human UN complex at a resolution of 2.7 Å and hNpl4 at a resolution of 3.0 Å. We also present atomic details and characterization of the human UN complex. Crystallographic studies and site-directed mutagenesis of the hUfd1 residues involved in the interaction with hNpl4 revealed the atomic details of the two proteins.

Keywords: Npl4; Ufd1; endoplasmic reticulum-associated degradation, ERAD; p97; ubiquitin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases* / chemistry
  • Cell Cycle Proteins / metabolism
  • Endoplasmic Reticulum / metabolism
  • Humans
  • Nuclear Proteins / metabolism
  • Protein Binding
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins* / genetics
  • Saccharomyces cerevisiae Proteins* / metabolism
  • Ubiquitin / metabolism
  • Valosin Containing Protein / metabolism

Substances

  • Adenosine Triphosphatases
  • Nuclear Proteins
  • Ubiquitin
  • Valosin Containing Protein
  • Cell Cycle Proteins
  • Saccharomyces cerevisiae Proteins