Atg17 Recruits Atg9 to Organize the Pre-Autophagosomal Structure

Genes Cells. 2009 May;14(5):525-38. doi: 10.1111/j.1365-2443.2009.01299.x. Epub 2009 Apr 13.

Abstract

Autophagy is a degradation system of cytoplasmic proteins and organelles via formation of double-membrane vesicles called autophagosomes. In the yeast Saccharomyces cerevisiae, autophagosomes are formed via the pre-autophagosomal structure (PAS) in a manner dependent on Atg proteins. Under nutrient-rich condition, Atg9 is recruited to the PAS by binding to Atg11 for the Cvt pathway. However, because Atg9 is recruited to the PAS in atg11Delta cells in starved condition and autophagy is induced, autophagy-specific mechanism for the Atg9 recruitment to the PAS has been assumed. Here, we demonstrate that, in autophagy-inducing condition, Atg9 is recruited to the PAS in a manner dependent on Atg17. Atg9 physically interacts with Atg17 in the presence of rapamycin. This interaction requires Atg1, a protein kinase essential for autophagy. Consistently, the Atg17-dependent PAS localization of Atg9 requires Atg1. However, its kinase activity is dispensable for this process. It rather regulates the equilibrium of assembly and disassembly of Atg9 at the PAS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Autophagy / drug effects
  • Autophagy / physiology*
  • Autophagy-Related Proteins
  • Carrier Proteins / drug effects
  • Carrier Proteins / metabolism*
  • Membrane Proteins / drug effects
  • Membrane Proteins / metabolism*
  • Phagosomes / drug effects
  • Phagosomes / metabolism*
  • Protein Binding
  • Protein Kinases / metabolism
  • Protein Transport / physiology
  • Saccharomyces cerevisiae / cytology*
  • Saccharomyces cerevisiae / drug effects
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / drug effects
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Sirolimus / pharmacology

Substances

  • ATG9 protein, S cerevisiae
  • Atg17 protein, S cerevisiae
  • Autophagy-Related Proteins
  • Carrier Proteins
  • Membrane Proteins
  • Saccharomyces cerevisiae Proteins
  • Protein Kinases
  • ATG1 protein, S cerevisiae
  • Sirolimus