title: Functional characterization of the Aspergillus fumigatus CRZ1 homologue, CrzA.
abstract: The protein phosphatase calcineurin is an important mediator connecting calcium-dependent signalling to various cellular responses in multiple organisms. In fungi calcineurin acts largely through regulating Crz1p-like transcription factors. Here we characterize an Aspergillus fumigatus CRZ1 homologue, CrzA and demonstrate its mediation of cellular tolerance to increased concentrations of calcium and manganese. In addition to acute sensitivity to these ions, and decreased conidiation, the crzA null mutant suffers altered expression of calcium transporter mRNAs under high concentrations of calcium, and loss of virulence when compared with the corresponding complemented and wild-type strains. We use multiple expression analyses to probe the transcriptional basis of A. fumigatus calcium tolerance identifying several genes having calA and/or crzA dependent mRNA accumulation patterns. We also demonstrate that contrary to previous findings, the gene encoding the Aspergillus nidulans calcineurin subunit homologue, cnaA, is not essential and that the cnaA deletion mutant shares the morphological phenotypes observed in the corresponding A. fumigatus mutant, DeltacalA. Exploiting the A. nidulans model system, we have linked calcineurin activity with asexual developmental induction, finding that CrzA supports appropriate developmental induction in a calcineurin and brlA-dependent manner in both species.
authors.affiliation: Faculdade de Ciências Farmacêuticas de Ribeirão PretoUniversidade de São Paulo, São Paulo, Brazil.
authors.forename: Frederico Marianetti
authors.initials: FM
authors.lastname: Soriani
authors.forename: Iran
authors.initials: I
authors.lastname: Malavazi
authors.forename: Márcia Eliana
authors.initials: ME
authors.lastname: da Silva Ferreira
authors.forename: Marcela
authors.initials: M
authors.lastname: Savoldi
authors.forename: Marcia Regina
authors.initials: MR
authors.lastname: Von Zeska Kress
authors.forename: Maria Helena
authors.initials: MH
authors.lastname: de Souza Goldman
authors.forename: Omar
authors.initials: O
authors.lastname: Loss
authors.forename: Elaine
authors.initials: E
authors.lastname: Bignell
authors.forename: Gustavo Henrique
authors.initials: GH
authors.lastname: Goldman
mesh_terms: D001232:Aspergillus fumigatus / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D001233:Aspergillus nidulans / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D019703:Calcineurin / Q000235:genetics* / Q000378:metabolism; D002122:Calcium Chloride / Q000494:pharmacology; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D008345:Manganese / Q000494:pharmacology; D018613:Microscopy, Confocal; D009154:Mutation; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D005656:Fungal Proteins; D012333:RNA, Messenger; D008345:Manganese; D019703:Calcineurin; D002122:Calcium Chloride