Precise Expression of Is Crucial for Asexual Development, Virulence, and Survival of Aspergillus fumigatus.

The rise of drug resistance in fungal pathogens is becoming a serious problem owing to the limited number of antifungal drugs available. Identifying and targeting factors essential for virulence or development unique to fungal pathogens is one approach to develop novel treatments for fungal infections. In this study, we present the identification and functional characterization of a novel developmental regulator in , AfMed15, which contained a conserved Med15_fungal domain, as determined by screening of a mutant library that contained more than 2,000 hygromycin-resistant transformants. Downregulating the expression of abolished the conidiation and decreased the fungal virulence in an insect model. Strikingly, the overexpression of caused fungal death accompanied by intensive autophagy. RNA sequencing of an overexpression strain revealed that altered gene expression patterns were associated with carbon metabolism, energy metabolism, and translation. Interestingly, the addition of metal ions could partially rescue fungal death caused by the overexpression of , indicating that disordered ion homeostasis is a potential reason for the fungal death caused by the overexpression of Considering that the precise expression of is crucial for fungal development, virulence, and survival and that no ortholog was found in humans, is an ideal target for antifungal-drug development. The identification and characterization of regulators essential for virulence or development constitute one approach for antifungal drug development. In this study, we screened and functionally characterized , a novel developmental regulator in We demonstrate that the precise transcriptional expression of is crucial for fungal asexual development, virulence, and survival. Downregulating the expression of abolished the conidiation and decreased the fungal virulence in an insect model. In contrast, the overexpression of caused fungal death accompanied by intensive autophagy. Our study provides a foundation for further studies to identify compounds perturbing the expression of that may be used for the prevention of invasive infections.