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Identification of ENA1 as a virulence gene of the human pathogenic fungus Cryptococcus neoformans through signature-tagged insertional mutagenesis.

Publication ,  Journal Article
Idnurm, A; Walton, FJ; Floyd, A; Reedy, JL; Heitman, J
Published in: Eukaryot Cell
March 2009

A library of more than 4,500 signature-tagged insertion mutants of the human pathogenic fungus Cryptococcus neoformans was generated, and a subset was screened in a murine inhalation model to identify genes required for virulence. New genes that regulate aspects of C. neoformans virulence were also identified by screening the entire library for in vitro phenotypes related to the ability to cause disease, including melanin production, growth at high temperature, and growth under conditions of nutrient limitation. A screen of 10% of the strain collection in mice identified an avirulent mutant strain with an insertion in the ENA1 gene, which is predicted to encode a fungus-specific sodium or potassium P-type ATPase. The results of the deletion of the gene and complementation experiments confirmed its key role in mammalian virulence. ena1 mutant strains exhibited no change in sensitivity to high salt concentrations but were sensitive to alkaline pH conditions, providing evidence that the fungus may have to survive at elevated pH during infection of the mammalian host. The mutation of the well-characterized virulence factor calcineurin (CNA1) also rendered C. neoformans strains sensitive to elevated pH. ENA1 transcripts in wild-type and cna1 mutant strains were upregulated in response to high pH, and cna1 ena1 double mutant strains exhibited increased sensitivity to elevated pH, indicating that at least two pathways in the fungus mediate survival under alkaline conditions. Signature-tagged mutagenesis is an effective strategy for the discovery of new virulence genes in fungal pathogens of animals.

Duke Scholars

Published In

Eukaryot Cell

DOI

EISSN

1535-9786

Publication Date

March 2009

Volume

8

Issue

3

Start / End Page

315 / 326

Location

United States

Related Subject Headings

  • Virulence Factors
  • Mutagenesis, Insertional
  • Microbiology
  • Mice
  • Humans
  • Cryptococcus neoformans
  • Cryptococcosis
  • Animals
  • Adenosine Triphosphatases
  • 3107 Microbiology
 

Citation

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Idnurm, A., Walton, F. J., Floyd, A., Reedy, J. L., & Heitman, J. (2009). Identification of ENA1 as a virulence gene of the human pathogenic fungus Cryptococcus neoformans through signature-tagged insertional mutagenesis. Eukaryot Cell, 8(3), 315–326. https://doi.org/10.1128/EC.00375-08
Idnurm, Alexander, Felicia J. Walton, Anna Floyd, Jennifer L. Reedy, and Joseph Heitman. “Identification of ENA1 as a virulence gene of the human pathogenic fungus Cryptococcus neoformans through signature-tagged insertional mutagenesis.Eukaryot Cell 8, no. 3 (March 2009): 315–26. https://doi.org/10.1128/EC.00375-08.
Idnurm, Alexander, et al. “Identification of ENA1 as a virulence gene of the human pathogenic fungus Cryptococcus neoformans through signature-tagged insertional mutagenesis.Eukaryot Cell, vol. 8, no. 3, Mar. 2009, pp. 315–26. Pubmed, doi:10.1128/EC.00375-08.

Published In

Eukaryot Cell

DOI

EISSN

1535-9786

Publication Date

March 2009

Volume

8

Issue

3

Start / End Page

315 / 326

Location

United States

Related Subject Headings

  • Virulence Factors
  • Mutagenesis, Insertional
  • Microbiology
  • Mice
  • Humans
  • Cryptococcus neoformans
  • Cryptococcosis
  • Animals
  • Adenosine Triphosphatases
  • 3107 Microbiology