Fungal Morphology, Iron Homeostasis, and Lipid Metabolism Regulated by a GATA Transcription Factor in Blastomyces dermatitidis - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue PLoS Pathogens Année : 2015

Fungal Morphology, Iron Homeostasis, and Lipid Metabolism Regulated by a GATA Transcription Factor in Blastomyces dermatitidis

Amber Marty
  • Fonction : Auteur
Aimee Broman
  • Fonction : Auteur
Robert Zarnowski
  • Fonction : Auteur
Teigan Dwyer
  • Fonction : Auteur
Laura Bond
  • Fonction : Auteur
James Ntambi
  • Fonction : Auteur
Sündüz Keleş
  • Fonction : Auteur
Christina Kendziorski
  • Fonction : Auteur
Gregory Gauthier
  • Fonction : Auteur

Résumé

In response to temperature, Blastomyces dermatitidis converts between yeast and mold forms. Knowledge of the mechanism(s) underlying this response to temperature remains limited. In B. dermatitidis, we identified a GATA transcription factor, SREB, important for the transition to mold. Null mutants (SREBΔ) fail to fully complete the conversion to mold and cannot properly regulate siderophore biosynthesis. To capture the transcriptional response regulated by SREB early in the phase transition (0–48 hours), gene expression microarrays were used to compare SREB∆ to an isogenic wild type isolate. Analysis of the time course microarray data demonstrated SREB functioned as a transcriptional regulator at 37°C and 22°C. Bioinformatic and biochemical analyses indicated SREB was involved in diverse biological processes including iron homeostasis, biosynthesis of triacylglycerol and ergosterol, and lipid droplet formation. Integration of microarray data, bioinformatics, and chromatin immunoprecipitation identified a subset of genes directly bound and regulated by SREB in vivo in yeast (37°C) and during the phase transition to mold (22°C). This included genes involved with siderophore biosynthesis and uptake, iron homeostasis, and genes unrelated to iron assimilation. Functional analysis suggested that lipid droplets were actively metabolized during the phase transition and lipid metabolism may contribute to filamentous growth at 22°C. Chromatin immunoprecipitation, RNA interference, and overexpression analyses suggested that SREB was in a negative regulatory circuit with the bZIP transcription factor encoded by HAPX. Both SREB and HAPX affected morphogenesis at 22°C; however, large changes in transcript abundance by gene deletion for SREB or strong overexpression for HAPX were required to alter the phase transition.

Dates et versions

hal-04322599 , version 1 (05-12-2023)

Identifiants

Citer

Amber Marty, Aimee Broman, Robert Zarnowski, Teigan Dwyer, Laura Bond, et al.. Fungal Morphology, Iron Homeostasis, and Lipid Metabolism Regulated by a GATA Transcription Factor in Blastomyces dermatitidis. PLoS Pathogens, 2015, 11 (6), pp.e1004959. ⟨10.1371/journal.ppat.1004959⟩. ⟨hal-04322599⟩
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