Efg1 Controls caspofungin-induced cell aggregation of Candida albicans through the adhesin Als1

Eukaryot Cell. 2011 Dec;10(12):1694-704. doi: 10.1128/EC.05187-11. Epub 2011 Oct 28.

Abstract

Echinocandin drugs such as caspofungin (CASP), micafungin, and anidulafungin inhibit fungal cell wall biogenesis by blocking Fks1-mediated β-glucan deposition into the cell surface. Candins have become suitable drugs to treat life-threatening diseases caused by several fungal species, including Candida albicans, that are pathogenic for humans. Here, we present the discovery of a novel CASP-induced flocculation phenotype of C. albicans, which formed large cell aggregates in the presence of CASP. High concentrations of sugars such as mannose or glucose inhibit CASP-induced flocculation and improve survival of C. albicans cells exposed to CASP. Notably, exposure of C. albicans cells to CASP triggers Efg1-dependent expression of the adhesin ALS1 and induces invasive growth on agar plates. Indeed, cells lacking either Efg1 or Als1 show strongly diminished CASP-induced flocculation, and the absence of Efg1 leads to marked CASP hypersensitivity. On the other hand, CASP-induced invasive growth is enhanced in cells lacking Efg1. Hence, CASP stress drives an Efg1-dependent response, indicating that this multifunctional transcriptional regulator, which is otherwise involved in filamentation, white-to-opaque switching, and virulence, also modulates cell wall remodeling upon CASP challenge. Taken together, our data suggest that CASP-induced cell wall damage activates Efg1 in parallel with the known cell integrity stress signaling pathway to coordinate cell wall remodeling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antifungal Agents / antagonists & inhibitors
  • Antifungal Agents / pharmacology*
  • Candida albicans / drug effects*
  • Candida albicans / genetics
  • Candida albicans / growth & development
  • Candida albicans / metabolism
  • Caspofungin
  • Cell Adhesion / drug effects
  • Cell Wall / metabolism
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Drug Resistance, Fungal / genetics
  • Echinocandins / antagonists & inhibitors
  • Echinocandins / pharmacology*
  • Flocculation / drug effects
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism*
  • Gene Expression / drug effects
  • Genes, Reporter
  • Glucose / pharmacology
  • Green Fluorescent Proteins / biosynthesis
  • Green Fluorescent Proteins / genetics
  • Lipopeptides
  • Mannose / pharmacology
  • Microbial Viability / drug effects
  • Mitogen-Activated Protein Kinases / metabolism
  • Phosphorylation
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*

Substances

  • ALS1 protein, Candida albicans
  • Antifungal Agents
  • DNA-Binding Proteins
  • EFG1 protein, Candida albicans
  • Echinocandins
  • Fungal Proteins
  • Lipopeptides
  • Transcription Factors
  • Green Fluorescent Proteins
  • MKC1 protein, Candida albicans
  • Mitogen-Activated Protein Kinases
  • Caspofungin
  • Glucose
  • Mannose