A novel family of dehydrin-like proteins is involved in stress response in the human fungal pathogen Aspergillus fumigatus

Mol Biol Cell. 2011 Jun 1;22(11):1896-906. doi: 10.1091/mbc.E10-11-0914. Epub 2011 Apr 13.

Abstract

During a search for genes controlling conidial dormancy in Aspergillus fumigatus, two dehydrin-like genes, DprA and DprB, were identified. The deduced proteins had repeated stretches of 23 amino acids that contained a conserved dehydrin-like protein (DPR) motif. Disrupted DprAΔ mutants were hypersensitive to oxidative stress and to phagocytic killing, whereas DprBΔ mutants were impaired in osmotic and pH stress responses. However, no effect was observed on their pathogenicity in our experimental models of invasive aspergillosis. Molecular dissection of the signaling pathways acting upstream showed that expression of DprA was dependent on the stress-activated kinase SakA and the cyclic AMP-protein kinase A (cAMP-PKA) pathways, which activate the bZIP transcription factor AtfA, while expression of DprB was dependent on the SakA mitogen-activated protein kinase (MAPK) pathway, and the zinc finger transcription factor PacC. Fluorescent protein fusions showed that both proteins were associated with peroxisomes and the cytosol. Accordingly, DprA and DprB were important for peroxisome function. Our findings reveal a novel family of stress-protective proteins in A. fumigatus and, potentially, in filamentous ascomycetes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Aspergillosis
  • Aspergillus fumigatus / genetics
  • Aspergillus fumigatus / pathogenicity
  • Aspergillus fumigatus / physiology*
  • Catalase / metabolism
  • Dithiothreitol / pharmacology
  • Enzyme Assays
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism*
  • Gene Expression Regulation, Fungal
  • Humans
  • Hydrogen-Ion Concentration
  • MAP Kinase Signaling System
  • Mice
  • Molecular Chaperones / genetics
  • Molecular Chaperones / metabolism*
  • Molecular Sequence Data
  • Osmotic Pressure
  • Oxidation-Reduction
  • Peroxisomes / enzymology
  • Phenotype
  • Sequence Alignment
  • Sequence Deletion
  • Spores, Fungal / genetics*
  • Stress, Physiological*
  • Transcription, Genetic
  • Unfolded Protein Response / drug effects

Substances

  • Fungal Proteins
  • Molecular Chaperones
  • Catalase
  • Dithiothreitol