Involvement of MAK-1 and MAK-2 MAP kinases in cell wall integrity in Neurospora crassa.
Among three MAPK disruptants of Neurospora crassa, Δmak-1 was sensitive and Δmak-2 was hypersensitive to micafungin, a beta-1,3-glucan synthase inhibitor, than the wild-type or Δos-2 strains. We identified six micafungin-inducible genes that are involved in cell wall integrity (CWI) and found that MAK-1 regulated the transcription of non-anchored cell wall protein gene, ncw-1, and the beta-1,3-endoglucanase gene, bgt-2, whereas MAK-2 controlled the expression of the glycosylhydrolase-like protein gene, gh76-5, and the C4-dicarboxylate transporter gene, tdt-1. Western blotting analysis revealed that, in the wild-type strain, MAK-1 was constitutively phosphorylated from conidial germination to hyphal development. In contrast, the phosphorylation of MAK-2 was growth phase-dependent, and micafungin induced the phosphorylation of unphosphorylated MAK-2. It should be noted that the phosphorylation of MAK-1 was virtually abolished in the Δmak-2 strain, but was significantly induced by micafungin, suggesting functional cross talk between MAK-1 and MAK-2 signalling pathway in CWI.
a Faculty of Life Sciences , Toyo University , Oura-gun , Japan.|c Department of Microbiology , University of Georgia , Athens , GA , USA.
Masayuki
M
Kamei
a Faculty of Life Sciences , Toyo University , Oura-gun , Japan.
Kazuhiro
K
Yamashita
a Faculty of Life Sciences , Toyo University , Oura-gun , Japan.
Masakazu
M
Takahashi
b Faculty of Food and Nutritional Sciences , Toyo University , Oura-gun , Japan.
Fumiyasu
F
Fukumori
a Faculty of Life Sciences , Toyo University , Oura-gun , Japan.
Akihiko
A
Ichiishi
a Faculty of Life Sciences , Toyo University , Oura-gun , Japan.
Makoto
M
Fujimura
D002473:Cell Wall / Q000201:enzymology* / Q000235:genetics; D054714:Echinocandins / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005656:Fungal Proteins / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D043326:Glucan 1,3-beta-Glucosidase / Q000235:genetics*; D025301:Hyphae / Q000235:genetics; D055666:Lipopeptides / Q000494:pharmacology; D020935:MAP Kinase Signaling System / Q000187:drug effects; D000077551:Micafungin; D019950:Mitogen-Activated Protein Kinase 1 / Q000235:genetics*; D009492:Neurospora crassa / Q000201:enzymology / Q000235:genetics; D047071:beta-Glucans / Q000378:metabolism
D054714:Echinocandins; D004791:Enzyme Inhibitors; D005656:Fungal Proteins; D055666:Lipopeptides; D047071:beta-Glucans; C033363:beta-1,3-glucan; D019950:Mitogen-Activated Protein Kinase 1; D043326:Glucan 1,3-beta-Glucosidase; D000077551:Micafungin
MAP kinase; Neurospora crassa; cell wall integrity; micafungin