LC3C, bound selectively by a noncanonical LIR motif in NDP52, is required for antibacterial autophagy

Mol Cell. 2012 Nov 9;48(3):329-42. doi: 10.1016/j.molcel.2012.08.024. Epub 2012 Sep 27.

Abstract

Autophagy protects cellular homeostasis by capturing cytosolic components and invading pathogens for lysosomal degradation. Autophagy receptors target cargo to autophagy by binding ATG8 on autophagosomal membranes. The expansion of the ATG8 family in higher eukaryotes suggests that specific interactions with autophagy receptors facilitate differential cargo handling. However, selective interactors of ATG8 orthologs are unknown. Here we show that the selectivity of the autophagy receptor NDP52 for LC3C is crucial for innate immunity since cells lacking either protein cannot protect their cytoplasm against Salmonella. LC3C is required for antibacterial autophagy because in its absence the remaining ATG8 orthologs do not support efficient antibacterial autophagy. Structural analysis revealed that the selectivity of NDP52 for LC3C is conferred by a noncanonical LIR, in which lack of an aromatic residue is balanced by LC3C-specific interactions. Our report illustrates that specificity in the interaction between autophagy receptors and autophagy machinery is of functional importance to execute selective autophagy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Motifs / genetics
  • Amino Acid Sequence
  • Autophagy*
  • Blotting, Western
  • Crystallography, X-Ray
  • Cytoplasm / metabolism
  • Cytoplasm / microbiology
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • HEK293 Cells
  • HeLa Cells
  • Humans
  • Microscopy, Fluorescence
  • Microtubule-Associated Proteins / chemistry
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism*
  • Models, Molecular
  • Molecular Sequence Data
  • Nuclear Proteins / chemistry
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Protein Binding
  • Protein Structure, Tertiary
  • RNA Interference
  • Salmonella / classification
  • Salmonella / metabolism*
  • Salmonella typhimurium / metabolism
  • Sequence Homology, Amino Acid
  • Species Specificity

Substances

  • CALCOCO2 protein, human
  • Microtubule-Associated Proteins
  • Nuclear Proteins
  • light chain 3, human
  • Green Fluorescent Proteins

Associated data

  • PDB/3VVV
  • PDB/3VVW