Multi-site-mediated entwining of the linear WIR-motif around WIPI β-propellers for autophagy

Nat Commun. 2020 Jun 1;11(1):2702. doi: 10.1038/s41467-020-16523-y.

Abstract

WIPI proteins (WIPI1-4) are mammalian PROPPIN family phosphoinositide effectors essential for autophagosome biogenesis. In addition to phosphoinositides, WIPI proteins can recognize a linear WIPI-interacting-region (WIR)-motif, but the underlying mechanism is poorly understood. Here, we determine the structure of WIPI3 in complex with the WIR-peptide from ATG2A. Unexpectedly, the WIR-peptide entwines around the WIPI3 seven-bladed β-propeller and binds to three sites in blades 1-3. The N-terminal part of the WIR-peptide forms a short strand that augments the periphery of blade 2, the middle segment anchors into an inter-blade hydrophobic pocket between blades 2-3, and the C-terminal aromatic tail wedges into another tailored pocket between blades 1-2. Mutations in three peptide-binding sites disrupt the interactions between WIPI3/4 and ATG2A and impair the ATG2A-mediated autophagic process. Thus, WIPI proteins recognize the WIR-motif by multi-sites in multi-blades and this multi-site-mediated peptide-recognition mechanism could be applicable to other PROPPIN proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / chemistry
  • Adaptor Proteins, Signal Transducing / genetics*
  • Adaptor Proteins, Signal Transducing / metabolism
  • Amino Acid Motifs / genetics*
  • Amino Acid Sequence
  • Animals
  • Autophagy / genetics*
  • Autophagy-Related Proteins / chemistry
  • Autophagy-Related Proteins / genetics*
  • Autophagy-Related Proteins / metabolism
  • Binding Sites / genetics
  • Cell Line
  • Crystallography, X-Ray
  • HEK293 Cells
  • Humans
  • Multiprotein Complexes / chemistry
  • Multiprotein Complexes / metabolism
  • Mutation
  • Peptides / chemistry
  • Peptides / genetics
  • Peptides / metabolism
  • Protein Binding
  • Protein Conformation
  • Sequence Homology, Amino Acid

Substances

  • ATG2A protein, human
  • Adaptor Proteins, Signal Transducing
  • Autophagy-Related Proteins
  • Multiprotein Complexes
  • Peptides
  • WDR45B protein, human