Properties of Putative APSES Transcription Factor AfpA in Aspergillus fumigatus

Aspergillus fumigatus is a major opportunistic pathogenic fungus that causes invasive aspergillosis with high mortality rates in immunocompromised patients. APSES family transcription factors regulate fungal development and virulence, but the function of the putative APSES-type transcription factor AfpA (AFUA_5g11390) remains uncharacterized. To investigate the roles of AfpA in A. fumigatus, we constructed the ΔafpA mutant and performed phenotypic analyses, RT-qPCR analyses, and virulence studies. The ΔafpA mutant exhibited reduced vegetative growth but increased conidiation, with upregulation of asexual developmental regulators brlA, abaA, and wetA. AfpA positively regulated cAMP-PKA signaling, resulting in delayed conidia germination. Furthermore, the mutant responded differently to external stresses and displayed enhanced virulence in neutropenic mice. In conclusion, AfpA functions as a multifaceted regulator balancing growth, development, and pathogenicity in A. fumigatus.