The iron-responsive microsomal proteome of Aspergillus fumigatus

Aspergillus fumigatus is an opportunistic fungal pathogen. Siderophore biosynthesis and iron acquisition are essential for virulence. Yet, limited data exist with respect to the adaptive nature of the fungal microsomal proteome under iron-limiting growth conditions, as encountered during host infection. Here, we demonstrate that under siderophore biosynthetic conditions — significantly elevated fusarinine C (FSC) and triacetylfusarinine C (TAFC) production (p 0.96 within groups; biological replicates (n = 4)). Quantitative and qualitative comparison revealed 231 proteins with a significant change in abundance between the iron-replete and iron-deplete conditions (p < 0.05, fold change ≥ 2), with 96 proteins showing increased abundance and 135 with decreased abundance following iron limitation, including predicted siderophore transporters. Fluorescently labelled FSC was only sequestered following A. fumigatus growth under iron-limiting conditions. Interestingly, human sera exhibited significantly increased reactivity (p < 0.0001) against microsomal protein extracts obtained following iron-deplete growth