title: The function of MoGlk1 in integration of glucose and ammonium utilization in Magnaporthe oryzae.
abstract: Hexokinases are conserved proteins functioning in glucose sensing and signaling. The rice blast fungus Magnaporthe oryzae contains several hexokinases, including MoHxk1 (hexokinase) and MoGlk1 (glucokinase) encoded respectively by MoHXK1 and MoGLK1 genes. The heterologous expression of MoGlk1 and MoHxk1 in Saccharomyces cerevisiae confirmed their conserved functions. Disruption of MoHXK1 resulted in growth reduction in medium containing fructose as the sole carbon source, whereas disruption of MoGLK1 did not cause the similar defect. However, the ΔMoglk1 mutant displayed decreased proton extrusion and a lower biomass in the presence of ammonium, suggesting a decline in the utilization of ammonium. Additionally, the MoGLK1 allele lacking catalytic activity restored growth to the ΔMoglk1 mutant. Moreover, the expression of MoPMA1 encoding a plasma membrane H(+)-ATPase decreased in the ΔMoglk1 mutant that can be suppressed by glucose and G-6-P. Thus, MoGlk1, but not MoHxk1, regulates ammonium utilization through a mechanism that is independent from its catalytic activity.
authors.affiliation: Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China.
authors.forename: Lisha
authors.initials: L
authors.lastname: Zhang
authors.forename: Ruili
authors.initials: R
authors.lastname: Lv
authors.forename: Xianying
authors.initials: X
authors.lastname: Dou
authors.forename: Zhongqiang
authors.initials: Z
authors.lastname: Qi
authors.forename: Chenlei
authors.initials: C
authors.lastname: Hua
authors.forename: Haifeng
authors.initials: H
authors.lastname: Zhang
authors.forename: Zhengyi
authors.initials: Z
authors.lastname: Wang
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Zheng
authors.forename: Zhengguang
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000143:Acids; D055162:Biocatalysis / Q000187:drug effects; D003470:Culture Media / Q000494:pharmacology; D005656:Fungal Proteins / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D005800:Genes, Fungal / Q000235:genetics; D005816:Genetic Complementation Test; D005947:Glucose / Q000378:metabolism* / Q000494:pharmacology; D020082:Magnaporthe / Q000166:cytology / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D000644:Quaternary Ammonium Compounds / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000378:metabolism; D017422:Sequence Analysis, DNA
chemical_list: D000143:Acids; D003470:Culture Media; D005656:Fungal Proteins; D000644:Quaternary Ammonium Compounds; D005947:Glucose