Selective autophagy regulates insertional mutagenesis by the Ty1 retrotransposon in Saccharomyces cerevisiae

Dev Cell. 2011 Aug 16;21(2):358-65. doi: 10.1016/j.devcel.2011.06.023.

Abstract

Macroautophagy (autophagy) is a bulk degradation system for cytoplasmic components and is ubiquitously found in eukaryotic cells. Autophagy is induced under starvation conditions and plays a cytoprotective role by degrading unwanted cytoplasmic materials. The Ty1 transposon, a member of the Ty1/copia superfamily, is the most abundant retrotransposon in the yeast Saccharomyces cerevisiae and acts to introduce mutations in the host genome via Ty1 virus-like particles (VLPs) localized in the cytoplasm. Here we show that selective autophagy downregulates Ty1 transposition by eliminating Ty1 VLPs from the cytoplasm under nutrient-limited conditions. Ty1 VLPs are targeted to autophagosomes by an interaction with Atg19. We propose that selective autophagy safeguards genome integrity against excessive insertional mutagenesis caused during nutrient starvation by transposable elements in eukaryotic cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Autophagy / genetics*
  • Genes, Fungal*
  • Green Fluorescent Proteins / genetics
  • Microscopy, Electron, Transmission
  • Models, Biological
  • Molecular Sequence Data
  • Mutagenesis, Insertional / physiology*
  • Nitrogen / deficiency
  • Phagosomes / genetics
  • Phagosomes / metabolism
  • Phagosomes / ultrastructure
  • Protein Structure, Tertiary / genetics
  • Retroelements / genetics
  • Retroelements / physiology*
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / physiology*
  • Saccharomyces cerevisiae / ultrastructure
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Transcription, Genetic
  • Vesicular Transport Proteins / genetics
  • Vesicular Transport Proteins / metabolism

Substances

  • Retroelements
  • Saccharomyces cerevisiae Proteins
  • Vesicular Transport Proteins
  • Green Fluorescent Proteins
  • Nitrogen