Transcriptome and biochemical analysis reveals that suppression of GPI-anchor synthesis leads to autophagy and possible necroptosis in Aspergillus fumigatus

PLoS One. 2013;8(3):e59013. doi: 10.1371/journal.pone.0059013. Epub 2013 Mar 18.

Abstract

Previously, it has been shown that GPI proteins are required for cell wall synthesis and organization in Aspergillus fumigatus, a human opportunistic pathogen causing life-threatening invasive aspergillosis (IA) in immunocompromised patients. Blocking GPI anchor synthesis leads to severe phenotypes such as cell wall defects, increased cell death, and attenuated virulence. However, the mechanism by which these phenotypes are induced is unclear. To gain insight into global effects of GPI anchoring in A. fumigatus, in this study a conditional expression mutant was constructed and a genome wide transcriptome analysis was carried out. Our results suggested that suppression of GPI anchor synthesis mainly led to activation of phosphatidylinositol (PtdIns) signaling and ER stress. Biochemical and morphological evidence showed that autophagy was induced in response to suppression of the GPI anchor synthesis, and also an increased necroptosis was observed. Based on our results, we propose that activation of PtdIns3K and increased cytosolic Ca(2+), which was induced by both ER stress and PtdIns signaling, acted as the main effectors to induce autophagy and possible necroptosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / genetics
  • Aspergillus fumigatus / genetics*
  • Aspergillus fumigatus / metabolism*
  • Aspergillus fumigatus / ultrastructure
  • Autophagy / genetics*
  • Calcium / metabolism
  • Cell Wall / chemistry
  • Cell Wall / genetics
  • Cell Wall / metabolism
  • Cytosol / metabolism
  • Endoplasmic Reticulum Stress / genetics
  • GPI-Linked Proteins / genetics
  • GPI-Linked Proteins / metabolism
  • Gene Expression Profiling*
  • Gene Order
  • Glycosylphosphatidylinositols / biosynthesis*
  • Membrane Proteins / genetics
  • Mutation
  • Phosphatidylinositols / metabolism
  • Protein Biosynthesis
  • Signal Transduction

Substances

  • GPI-Linked Proteins
  • Glycosylphosphatidylinositols
  • Membrane Proteins
  • Phosphatidylinositols
  • phosphatidylinositol glycan-class A protein
  • Calcium

Associated data

  • GEO/GSE42499

Grants and funding

This work was funded by the National Natural Science Foundation of China (31030025) to CJ (http://nsfc.gov.cn/Porta10/default152.htm). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.