The isolation of FOS-1, a gene encoding a putative two-component histidine kinase from Aspergillus fumigatus

Fungal Genet Biol. 2000 Oct;31(1):55-67. doi: 10.1006/fgbi.2000.1225.


In fungi, two-component histidine kinases are involved in response mechanisms to extracellular changes in osmolarity, resistance to dicarboximide fungicides, and cell-wall assembly. In the human opportunistic fungus, Candida albicans, each of the three histidine kinases plays a role in virulence. Here, we identify, for the first time, a gene, FOS-1, from the human pathogenic fungus Aspergillus fumigatus that predicts a protein with homology to two-component histidine kinases. The predicted FOS-1 protein is highly homologous to bacterial and other fungal histidine kinases in several functional domains, but is divergent at the amino- and carboxy-termini. A mutant lacking the FOS-1 locus, DeltaFOS-1, did not exhibit a detectable defect in either hyphal growth or morphology when grown on solid or liquid medium. However, in liquid medium, conidiophore development of the DeltaFOS-1 mutant was delayed. Compared to wild type, the DeltaFOS-1 strain was neither osmotically sensitive nor sensitive or resistant to a number of nondicarboximide antifungal drugs, but was highly resistant to dicarboximide fungicides and resistant to novozym 234, suggesting that FOS-1p may play a role in the regulation of cell-wall assembly.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Antifungal Agents / pharmacology
  • Aspergillus fumigatus / drug effects
  • Aspergillus fumigatus / enzymology*
  • Aspergillus fumigatus / genetics*
  • Aspergillus fumigatus / growth & development
  • Cloning, Molecular
  • DNA, Fungal / analysis
  • DNA, Fungal / genetics
  • Fungal Proteins*
  • Gene Deletion
  • Genes, Fungal*
  • Histidine Kinase
  • Humans
  • Molecular Sequence Data
  • Phenotype
  • Protein Kinases / chemistry
  • Protein Kinases / genetics*
  • Protein Kinases / metabolism
  • Sequence Analysis, DNA


  • Antifungal Agents
  • DNA, Fungal
  • Fungal Proteins
  • Protein Kinases
  • Histidine Kinase
  • FOS-1 protein, Aspergillus fumigatus