title: ChIP-seq reveals a role for CrzA in the Aspergillus fumigatus high-osmolarity glycerol response (HOG) signalling pathway.
abstract: Aspergillus fumigatus is an opportunistic pathogen and allergen of mammals. Calcium signalling is essential for A. fumigatus pathogenicity and is regulated by the CrzA transcription factor. We used ChIP-seq (Chromatin Immunoprecipitation DNA sequencing) to explore CrzA gene targets in A. fumigatus. In total, 165 potential binding peaks including 102 directly regulated genes were identified, resulting in the prediction of the A[GT][CG]CA[AC][AG] CrzA-binding motif. The 102 CrzA putatively regulated genes exhibited a diverse array of functions. The phkB (Afu3g12530) histidine kinase and the sskB (Afu1g10940) MAP kinase kinase kinase of the HOG (high-osmolarity glycerol response) pathway were regulated by CrzA. Several members of the two-component system (TCS) and the HOG pathway were more sensitive to calcium. CrzA::GFP was translocated to the nucleus upon osmotic stress. CrzA is important for the phosphorylation of the SakA MAPK in response to osmotic shock. The ΔsskB was more sensitive to CaCl2 , NaCl, and paraquat stress, while being avirulent in a murine model of invasive pulmonary aspergillosis. The presence of CaCl2 and osmotic stresses resulted in synergistic inhibition of ΔcrzA and ΔsskB growth. These results suggest there is a genetic interaction between the A. fumigatus calcineurin-CrzA and HOG pathway that is essential for full virulence.
authors.affiliation: Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.
authors.forename: Patrícia A
authors.initials: PA
authors.lastname: de Castro
authors.forename: Chenxi
authors.initials: C
authors.lastname: Chen
authors.forename: Ricardo Sérgio Couto
authors.initials: RS
authors.lastname: de Almeida
authors.forename: Fernanda Z
authors.initials: FZ
authors.lastname: Freitas
authors.forename: Maria C
authors.initials: MC
authors.lastname: Bertolini
authors.forename: Enyara Rezende
authors.initials: ER
authors.lastname: Morais
authors.forename: Neil Andrew
authors.initials: NA
authors.lastname: Brown
authors.forename: Leandra Naira Zambelli
authors.initials: LN
authors.lastname: Ramalho
authors.forename: Daisuke
authors.initials: D
authors.lastname: Hagiwara
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Mitchell
authors.forename: Gustavo H
authors.initials: GH
authors.lastname: Goldman
mesh_terms: D000818:Animals; D001232:Aspergillus fumigatus / Q000235:genetics / Q000254:growth & development / Q000472:pathogenicity / Q000502:physiology*; D047369:Chromatin Immunoprecipitation; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D005990:Glycerol / Q000378:metabolism*; D008322:Mammals; D051379:Mice; D009994:Osmolar Concentration; D009997:Osmotic Pressure; D011485:Protein Binding; D018085:Regulon; D017422:Sequence Analysis, DNA; D015398:Signal Transduction; D013312:Stress, Physiological; D014774:Virulence
chemical_list: C530975:CrzA protein, Aspergillus fumigatus; D004271:DNA, Fungal; D005656:Fungal Proteins; D005990:Glycerol