A two-component histidine kinase of the rice blast fungus is involved in osmotic stress response and fungicide action

Differential Role of HAMP-like Linkers in Regulating the Functionality of the Group III Histidine Kinase DhNik1p

“…In their N terminus, they contain a poly-HAMP module, which is essential for osmosensing as well as cell death upon exposure to the antifungal agent fludioxonil (2,6,9,(33)(34)(35)(36). DhNik1p is a typical molecule of this class and contains five HAMP domains and four HAMP-like linkers (Fig.…”

Two-Component Signaling System in Filamentous Fungi and the Mode of Action of Dicarboximide and Phenylpyrrole Fungicides

“…However, Hik1 gene disruptants in M. grisea are highly sensitive to hyperosmotic stress with sorbitol, but not with certain solutes (KCl, NaCl and glycerol). In M. grisea, the involvement of HisK(s) other than Hik1 or an unknown hyperosmotic adaptation mechanism for these solutes has been suggested (Motoyama et al, 2005a).…”

Role of MAP Kinase Signaling in Secondary Metabolism and Adaptation to Abiotic/Fungicide Stress in Fusarium

“…Similarly to ∆hog1 mutants of other fungi, like Neurospora crassa, Aspergillus nidulans, C. heterostrophus and Colletotrichum lagenarium the ∆Fphog1 MAPK mutants of F. proliferatum became tolerant to phenylpyrrole and dicarboximide fungicides (Zhang et al, 2002;Noguchi et al, 2004;Yoshimi et al, 2005;Ádám et al, 2008b;Hagiwara et al, 2009). Although the exact mode of action of these compounds is still unclear, the finding that heterologous expression of Hik1, the histidine kinase (HK) gene of Magnaporthe oryzae in the yeast, S. cerevisiae that contain only one HK gene, Sln1 confers susceptibility in this otherwise fludioxonil-resistant organism, suggests that class III HKs, located upstream of the HOG1 MAPK cascade are possible targets of this fungicide (Motoyama et al, 2005). The class III HKs responsible for elevated osmo-tolerance and increased fludioxonil sensitivity in filamentous fungi are not the orthologues of Sln1 of the yeast (Catlett et al, 2003).…”

“…In silico analysis of HKs by reciprocal BLASTP searches in Fusarium genome sequences led to the identification of Fhk1 (FOXG_01684) orthologues both in F. verticillioides (hypothetical protein FVEG_08048) and F. graminearum (hypothetical protein FGSG_07118) (Nagygyörgy and Ádám, unpublished). HKs have five HAMP (histidine kinase, adenylate cyclase, methyl binding protein and phosphatase) repeats: mutations in these sequences are responsible for the increased osmosensitivity and fungicide resistance of N. crassa, C. heterostrophus, Alternaria brassicicola and Botrytis cinerea (Ochiai et al, 2001;Yoshimi et al, 2004;Motoyama et al, 2005;Viaud et al, 2006). Recent microarray analyses have further shown that the transcriptional response to fludioxonil depends on a Hog1 orthologue in A. nidulans.…”