title: Identification of OS-2 MAP kinase-dependent genes induced in response to osmotic stress, antifungal agent fludioxonil, and heat shock in Neurospora crassa.
abstract: Two-component signal transduction comprising of OS-1 (histidine kinase), OS-4 (MAPKK kinase), OS-5 (MAPK kinase), and OS-2 (MAP kinase) plays an important role in osmotic regulation in Neurospora crassa. To identify the genes regulated downstream of OS-2 MAP kinase, quantitative real-time RT-PCR analysis was conducted in selected genes based on Hog1 MAP kinase regulated genes in yeast. In response to osmotic stress and fludioxonil, expression of six genes that for glycerol synthesis (gcy-1, gcy-3, and dak-1), gluconeogenesis (fbp-1 and pck-1), and catalase (ctt-1) was activated in the wild-type strain, but not in the os-2 mutant. A heat shock treatment also induced their expression in the same way. Consisting with the gene expression, the enzyme activity of glycerol dehydrogenase, but not glycerol-3-phosphate dehydrogenase, was increased in response to osmotic stress and fludioxonil in the wild-type strain. OS-2 was phosphorylated by the OS-1 cascade in response to relatively low osmotic stress and fludioxonil. However, OS-2 phosphorylation by heat shock and a higher osmotic stress was found in the os-1 mutant normally but not in the os-4 and os-5 mutants. These results suggested that non-OS-1 signaling activates OS-2 in an OS-4-dependent manner in such conditions.
authors.affiliation: Faculty of Life Sciences, Toyo University, Itakura, Oura-Gun, Gunma, Japan.
authors.forename: Rieko
authors.initials: R
authors.lastname: Noguchi
authors.forename: Shinpei
authors.initials: S
authors.lastname: Banno
authors.forename: Ryota
authors.initials: R
authors.lastname: Ichikawa
authors.forename: Fumiyasu
authors.initials: F
authors.lastname: Fukumori
authors.forename: Akihiko
authors.initials: A
authors.lastname: Ichiishi
authors.forename: Makoto
authors.initials: M
authors.lastname: Kimura
authors.forename: Isamu
authors.initials: I
authors.lastname: Yamaguchi
authors.forename: Makoto
authors.initials: M
authors.lastname: Fujimura
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology; D004149:Dioxoles / Q000494:pharmacology*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects*; D005800:Genes, Fungal; D005993:Glycerolphosphate Dehydrogenase / Q000378:metabolism; D006358:Hot Temperature; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics* / Q000378:metabolism; D008957:Models, Genetic; D009154:Mutation; D009492:Neurospora crassa / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D009997:Osmotic Pressure; D010766:Phosphorylation / Q000187:drug effects; D011758:Pyrroles / Q000494:pharmacology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013401:Sugar Alcohol Dehydrogenases / Q000378:metabolism
chemical_list: D000935:Antifungal Agents; D004149:Dioxoles; D005656:Fungal Proteins; D011758:Pyrroles; D005993:Glycerolphosphate Dehydrogenase; D013401:Sugar Alcohol Dehydrogenases; C020672:glycerol dehydrogenase; D020928:Mitogen-Activated Protein Kinases; C108339:fludioxonil