RT Journal Article SR Electronic(1) A1 Sriranganadane, Dev A1 Reichard, Utz A1 Salamin, Karine A1 Fratti, Marina A1 Jousson, Olivier A1 Waridel, Patrice A1 Quadroni, Manfredo A1 Neuhaus, Jean-Marc A1 Monod, MichelYR 2011 T1 Secreted glutamic protease rescues aspartic protease Pep deficiency in Aspergillus fumigatus during growth in acidic protein medium JF Microbiology, VO 157 IS 5 SP 1541 OP 1550 DO https://doi.org/10.1099/mic.0.048603-0 PB Microbiology Society, SN 1465-2080, AB In an acidic protein medium Aspergillus fumigatus secretes an aspartic endoprotease (Pep) as well as tripeptidyl-peptidases, a prolyl-peptidase and carboxypeptidases. In addition, LC-MS/MS revealed a novel glutamic protease, AfuGprA, homologous to Aspergillus niger aspergillopepsin II. The importance of AfuGprA in protein digestion was evaluated by deletion of its encoding gene in A. fumigatus wild-type D141 and in a pepĪ” mutant. Either A. fumigatus Pep or AfuGprA was shown to be necessary for fungal growth in protein medium at low pH. Exoproteolytic activity is therefore not sufficient for complete protein hydrolysis and fungal growth in a medium containing proteins as the sole nitrogen source. Pep and AfuGprA constitute a pair of endoproteases active at low pH, in analogy to A. fumigatus alkaline protease (Alp) and metalloprotease I (Mep), where at least one of these enzymes is necessary for fungal growth in protein medium at neutral pH. Heterologous expression of AfuGprA in Pichia pastoris showed that the enzyme is synthesized as a preproprotein and that the propeptide is removed through an autoproteolytic reaction at low pH to generate the mature protease. In contrast to A. niger aspergillopepsin II, AfuGprA is a single-chain protein and is structurally more similar to G1 proteases characterized in other non-Aspergillus fungi., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.048603-0