Histatin 5 resistance of Candida glabrata can be reversed by insertion of Candida albicans polyamine transporter-encoding genes DUR3 and DUR31

PLoS One. 2013 Apr 22;8(4):e61480. doi: 10.1371/journal.pone.0061480. Print 2013.

Abstract

Candida albicans and Candida glabrata are predominant fungi associated with oral candidiasis. Histatin 5 (Hst 5) is a small cationic human salivary peptide with high fungicidal activity against C. albicans, however many strains of C. glabrata are resistant. Since Hst 5 requires fungal binding to cell wall components prior to intracellular translocation, reduced Hst 5 binding to C. glabrata may be the reason for its insensitivity. C. glabrata has higher surface levels of β-1,3-glucans as compared with C. albicans; however these differences did not account for reduced Hst 5 uptake and killing in C. glabrata. Similarly, the biofilm matrix of C. glabrata contained significantly higher levels of β-1,3-glucans compared with C. albicans, but it did not reduce the percentage of Hst 5 positive fungal cells in the biofilm. Hst 5 enters C. albicans cell through polyamine transporters Dur3p and Dur31p that are uncharacterized in C. glabrata. C. glabrata strains expressing CaDur3 and CaDur31 had two-fold higher killing and uptake of Hst 5. Thus, neither C. glabrata cell surface or biofilm matrix β-1,3-glucan levels affected Hst 5 toxicity; rather the crucial rate limiting step is reduced uptake that can be overcome by expression of C. albicans Dur proteins in C. glabrata.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Antifungal Agents / metabolism
  • Antifungal Agents / pharmacology
  • Biofilms / drug effects
  • Biofilms / growth & development
  • Candida albicans / genetics*
  • Candida glabrata / cytology
  • Candida glabrata / drug effects*
  • Candida glabrata / genetics*
  • Candida glabrata / physiology
  • Drug Resistance, Fungal / genetics*
  • Fungal Proteins / genetics*
  • Fungal Proteins / metabolism
  • Glucans / metabolism
  • Histatins / metabolism
  • Histatins / pharmacology*
  • Humans
  • Intracellular Space / drug effects
  • Intracellular Space / metabolism
  • Mutagenesis, Insertional*
  • Protein Transport / genetics
  • Spermidine / metabolism

Substances

  • Antifungal Agents
  • Fungal Proteins
  • Glucans
  • HTN3 protein, human
  • Histatins
  • Spermidine