Posttranslational hypusination of the eukaryotic translation initiation factor-5A regulates Fusarium graminearum virulence.
Activation of eukaryotic translation initiation factor eIF5A requires a posttranslational modification, forming the unique amino acid hypusine. This activation is mediated by two enzymes, deoxyhypusine synthase, DHS, and deoxyhypusine hydroxylase, DOHH. The impact of this enzymatic complex on the life cycle of a fungal pathogen is unknown. Plant pathogenic ascomycetes possess a single copy of the eIF5A activated by hypusination. We evaluated the importance of imbalances in eIF5A hypusination in Fusarium graminearum, a devastating fungal pathogen of cereals. Overexpression of DHS leads to increased virulence in wheat, elevated production of the mycotoxin deoxynivalenol, more infection structures, faster wheat tissue invasion in plants and increases vegetatively produced conidia. In contrast, overexpression of DOHH completely prevents infection structure formation, pathogenicity in wheat and maize, leads to overproduction of ROS, reduced DON production and increased sexual reproduction. Simultaneous overexpression of both genes restores wild type-like phenotypes. Analysis of eIF5A posttranslational modification displayed strongly increased hypusinated eIF5A in DOHH overexpression mutant in comparison to wild type, and the DHS overexpression mutants. These are the first results pointing to different functions of differently modified eIF5A.
University of Hamburg, Biocenter Klein Flottbek, Molecular Phytopathology and Genetics, Hamburg, D-22609, Germany.
Ana Lilia
AL
Martinez-Rocha
University of Hamburg, Biocenter Klein Flottbek, Molecular Phytopathology and Genetics, Hamburg, D-22609, Germany.
Mayada
M
Woriedh
Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Department Antiviral Strategies, Hamburg, D-20251, Germany.
Jan
J
Chemnitz
University of Hamburg, Biocenter Klein Flottbek, Molecular Phytopathology and Genetics, Hamburg, D-22609, Germany.
Peter
P
Willingmann
University of Hamburg, Biocenter Klein Flottbek, Molecular Phytopathology and Genetics, Hamburg, D-22609, Germany.
Cathrin
C
Kröger
University of Hamburg, Biocenter Klein Flottbek, Molecular Phytopathology and Genetics, Hamburg, D-22609, Germany.
Birgit
B
Hadeler
Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Department Antiviral Strategies, Hamburg, D-20251, Germany.|German Center for Infection Research (DZIF), partner site Hamburg, Hamburg, Germany.
Joachim
J
Hauber
University of Hamburg, Biocenter Klein Flottbek, Molecular Phytopathology and Genetics, Hamburg, D-22609, Germany.
Wilhelm
W
Schäfer
D005670:Fusarium / Q000472:pathogenicity / Q000502:physiology*; D015870:Gene Expression; D005800:Genes, Fungal; D008239:Lysine / Q000031:analogs & derivatives* / Q000096:biosynthesis; D050296:Microbial Viability / Q000235:genetics; D009154:Mutation; D009183:Mycotoxins / Q000096:biosynthesis; D010448:Peptide Initiation Factors / Q000235:genetics / Q000378:metabolism*; D010935:Plant Diseases; D011499:Protein Processing, Post-Translational; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013312:Stress, Physiological / Q000235:genetics; D014908:Triticum / Q000378:metabolism / Q000382:microbiology; D014774:Virulence; D000097574:Eukaryotic Translation Initiation Factor 5A
D008239:Lysine; D009183:Mycotoxins; D010448:Peptide Initiation Factors; D016601:RNA-Binding Proteins; D017382:Reactive Oxygen Species; D000097574:Eukaryotic Translation Initiation Factor 5A; C100028:hypusine