title: The putative stress sensor protein MtlA is required for conidia formation, cell wall stress tolerance, and cell wall integrity in Aspergillus nidulans.
abstract: The Mid2-like protein MtlA is a putative sensor of the cell wall integrity (CWI) signaling pathway in Aspergillus nidulans. An MtlA-EGFP fusion protein was localized at the cell surface and septa. The mtlA disruptant (∆mtlA) showed radial colony growth similar to the wild-type (wt) strain, but showed reduced conidia formation. The ∆mtlA mutant showed growth deficiency in the presence of inhibitors of cell wall synthesis. Moreover, mtlA disruption resulted in a reduction in the glucan and chitin content in the cell wall. These results suggest that MtlA plays a significant role in asexual sporulation, cell wall stress tolerance, and the maintenance of CWI in A. nidulans, but transcriptional upregulation of α-1,3-glucan synthase gene agsB induced by micafungin was observed in the ∆mtlA strain as well as the wt strain. Thus, MtlA is not essential for activation of the downstream CWI signaling pathway components identified in previous studies of Saccharomyces cerevisiae.
authors.affiliation: a Department of Bioscience and Biotechnology, Faculty of Agriculture , Kyushu University , Fukuoka , Japan.
authors.forename: Taiki
authors.initials: T
authors.lastname: Futagami
authors.forename: Kazufumi
authors.initials: K
authors.lastname: Seto
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kajiwara
authors.forename: Hideharu
authors.initials: H
authors.lastname: Takashita
authors.forename: Toshiro
authors.initials: T
authors.lastname: Omori
authors.forename: Kaoru
authors.initials: K
authors.lastname: Takegawa
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Goto
mesh_terms: D000595:Amino Acid Sequence; D001233:Aspergillus nidulans / Q000166:cytology* / Q000378:metabolism* / Q000502:physiology; D002473:Cell Wall / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D021381:Protein Transport; D017386:Sequence Homology, Amino Acid; D013172:Spores, Fungal / Q000502:physiology*; D013312:Stress, Physiological
chemical_list: D005656:Fungal Proteins
keywords: Aspergillus nidulans; MtlA; cell wall integrity; stress sensor