Apg16p is required for the function of the Apg12p-Apg5p conjugate in the yeast autophagy pathway

EMBO J. 1999 Jul 15;18(14):3888-96. doi: 10.1093/emboj/18.14.3888.

Abstract

Autophagy is an intracellular bulk degradation system that is ubiquitous for eukaryotic cells. In this process, cytoplasmic components are enclosed in autophagosomes and delivered to lysosomes/vacuoles. We recently found that a protein conjugation system, in which Apg12p is covalently attached to Apg5p, is indispensable for autophagy in yeast. Here, we describe a novel coiled-coil protein, Apg16p, essential for autophagy. Apg16p interacts with Apg12p-conjugated Apg5p and less preferentially with unconjugated Apg5p. Moreover, the coiled-coil domain of Apg16p mediates self-multimerization that leads to cross-linking of Apg5p molecules and formation of a stable protein complex. Apg16p is not essential for the Apg12p-Apg5p conjugation reaction. These results suggest that the Apg12p-Apg5p conjugate requires Apg16p to accomplish its role in the autophagy pathway, and Apg16p is a key molecule as a linker to form the Apg12p-Apg5p-Apg16p multimer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Autophagy*
  • Autophagy-Related Protein 5
  • Autophagy-Related Protein 7
  • Autophagy-Related Proteins
  • Carrier Proteins / chemistry
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cell Membrane / metabolism
  • Cloning, Molecular
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism
  • Gene Expression
  • Genes, Essential / genetics
  • Genes, Essential / physiology
  • Genes, Fungal / genetics
  • Genes, Fungal / physiology
  • Membrane Proteins / chemistry
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Molecular Sequence Data
  • Precipitin Tests
  • Protein Binding
  • Proteins / genetics
  • Proteins / metabolism*
  • Saccharomyces cerevisiae / cytology
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae / physiology*
  • Saccharomyces cerevisiae Proteins*
  • Sequence Deletion
  • Transcription Factors*
  • Ubiquitin-Protein Ligases

Substances

  • ATG16 protein, S cerevisiae
  • ATG5 protein, S cerevisiae
  • ATG7 protein, S cerevisiae
  • Autophagy-Related Protein 5
  • Autophagy-Related Proteins
  • Carrier Proteins
  • Fungal Proteins
  • Membrane Proteins
  • Proteins
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors
  • Ubiquitin-Protein Ligases
  • Autophagy-Related Protein 7