title: The role of AtfA and HOG MAPK pathway in stress tolerance in conidia of Aspergillus fumigatus.
abstract: Aspergillus fumigatus is a life-threatening pathogenic fungus, whose conidium is the infectious agent of aspergillosis. To better understand the mechanism underlying the long-term viability of conidia, we characterized a bZip transcription factor, AtfA, with special reference to stress-tolerance in conidia. The atfA deletion mutant conidia showed significant sensitivity to high temperature and oxidative stress. The trehalose content that accumulated in conidia was reduced in the mutant conidia. Transcriptome analysis revealed that AtfA regulated several stress-protection-related genes such as catA, dprA, scf1, and conJ at the conidiation stage. The upstream high-osmolarity glycerol pathway was also involved in conferring stress tolerance in conidia because ΔpbsB showed stress sensitivity and reduced trehalose in conidia. However, a mutant lacking the SakA mitogen-activated protein kinase (MAPK) produced normal conidia. We investigated another MAPK, MpkC, in relation with SakA, and the double deletion mutant, ΔsakA,mpkC, was defective in conidia stress tolerance. We concluded that MpkC is able to bypass SakA, and the two MAPKs redundantly regulate the conidia-related function of AtfA in A. fumigatus.
authors.affiliation: Medical Mycology Research Center (MMRC), Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8673, Japan. Electronic address: dhagi@chiba-u.jp.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Hagiwara
authors.affiliation: National Food Research Institute (NFRI), 2-1-12 Kan-nondai, Tsukuba, Ibaraki 305-8642, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Suzuki
authors.affiliation: Medical Mycology Research Center (MMRC), Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8673, Japan.
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Kamei
authors.affiliation: Medical Mycology Research Center (MMRC), Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8673, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Gonoi
authors.affiliation: Medical Mycology Research Center (MMRC), Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8673, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Kawamoto
mesh_terms: D001232:Aspergillus fumigatus / Q000502:physiology*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D013172:Spores, Fungal / Q000235:genetics / Q000378:metabolism*; D013312:Stress, Physiological; D059467:Transcriptome
chemical_list: D005656:Fungal Proteins
keywords: Aspergillus fumigatus; AtfA; Conidia; MAPK; Stress-tolerance; Trehalose