Aspergillus fumigatus transcriptome DeltaSchA

The serine-threonine kinase TOR, the Target of Rapamycin, is an important regulator of nutrient, energy, and stress signaling in eukaryotes. Sch9, a Ser/Thr kinase of AGC family (the cAMP-dependent PKA, cGMP- dependent protein kinase G and phospholipid-dependent protein kinase C family), is a substrate of TOR. Here, we characterized the Aspergillus fumigatus Sch9 homologue (SchA). The ?schA null mutant was sensitive to rapamycin, high concentrations of calcium, hyperosmotic stress, and was involved in iron metabolism. Transcriptomics and proteomics identified direct and indirect targets of SchA post exposure to hyperosmotic stress. The ?schA null mutant showed increased phosphorylation of SakA, the A. fumigatus Hog1 homologue. SchA::GFP localized in the mitochondria during non-stressing conditions, and upon osmotic or iron stresses it remained in the mitochondria, but these treatments induce a fission process in the mitochondrial morphology. Finally, ?schA was avirulent in a low dose murine infection model. Our results suggest a complex net of interactions among the SakA and TOR pathways occur via SchA.