FgNup2 regulates nuclear import of the histone H2B monoubiquitination enzyme by stabilizing the FgImpα-FgBre1 complex to mediate pathogenicity in Fusarium graminearum
- 1School of Plant Protection, Anhui Agricultural University, Hefei, China
- 2Key Laboratory of Agri‐Products Quality and Biosafety (Anhui Agricultural University), Ministry of Education, Hefei, China
Abstract
Fusarium head blight caused by Fusarium graminearum threatens global wheat production. The pathogenicity of this fungus depends on histone H2B monoubiquitination (H2Bub1), yet the nuclear import mechanism of its key enzyme, FgBre1, remains unclear. In this study, we identified 24 nucleoporins in F. graminearum and found that FgNup2 is essential for fungal growth, toxin biosynthesis, and virulence. FgNup2 positively regulates H2Bub1 levels by facilitating the nuclear import of FgBre1, thereby influencing pathogenic development. The nuclear import of FgBre1 relies on the importin receptor FgImpα, and these two proteins interact. FgNup2, through a critical phenylalanine residue (F981) within its FG-repeat domain, promotes and stabilizes the FgImpα–FgBre1 complex, driving the assembly of the tripartite FgNup2–FgImpα–FgBre1 complex. This ultimately mediates the rapid nuclear translocation of FgBre1 under induction by the trichothecene biosynthesis-inducing medium. Our findings reveal a mechanism by which a nucleoporin regulates the nuclear entry of a histone-modifying enzyme via stabilizing the importin–cargo complex, advancing the understanding of non-canonical roles of the nuclear pore complex in pathogen adaptation. Author summary: Fusarium head blight, caused by the fungal pathogen F. graminearum, is a devastating disease that leads to significant wheat yield losses and contamination of grains with mycotoxins. The pathogenicity of this fungus is associated with the H2Bub1 modification, which is executed by the enzyme FgBre1. For FgBre1 to function, it must be imported into the nucleus. However, the regulatory mechanisms governing its nuclear import have remained unclear. Here, we identified FgNup2, a component of the nuclear pore complex, as a master regulator of fungal growth, toxin production, and the ability to infect wheat. Beyond serving as a passive gatekeeper, FgNup2 actively facilitates the nuclear entry of FgBre1. It acts as a molecular scaffold, stabilizing the interaction between FgBre1 and the nuclear transport shuttle protein FgImpα. Within FgNup2, the amino acid residue F981 was found to be critical for maintaining this stability. Our study reveals a mechanism by which a pathogen regulates key biological processes through modulating nuclear pore transport function, offering a novel target for developing intervention strategies aimed at curbing the virulence of this fungus.
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BibTeX
@article{wang2026fgnup2,
title = {{FgNup2 regulates nuclear import of the histone H2B monoubiquitination enzyme by stabilizing the FgImpα-FgBre1 complex to mediate pathogenicity in Fusarium graminearum}},
author = {Yaxuan Wang and Zhe Li and Xiaoyan Wang and Bin Xiong and Chengqi Zhang and Xiaozhen Zhao and Shentao Wang and Li Chen},
journal = {PLOS Pathogens},
year = {2026},
month = sep,
doi = {10.1371/journal.ppat.1014577},
url = {https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1014577},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - FgNup2 regulates nuclear import of the histone H2B monoubiquitination enzyme by stabilizing the FgImpα-FgBre1 complex to mediate pathogenicity in Fusarium graminearum
AU - Yaxuan Wang
AU - Zhe Li
AU - Xiaoyan Wang
AU - Bin Xiong
AU - Chengqi Zhang
AU - Xiaozhen Zhao
AU - Shentao Wang
AU - Li Chen
PY - 2026
DA - 2026/09/15
JO - PLOS Pathogens
DO - 10.1371/journal.ppat.1014577
UR - https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1014577
AB - Fusarium head blight caused by Fusarium graminearum threatens global wheat production. The pathogenicity of this fungus depends on histone H2B monoubiquitination (H2Bub1), yet the nuclear import mechanism of its key enzyme, FgBre1, remains unclear. In this study, we identified 24 nucleoporins in F. graminearum and found that FgNup2 is essential for fungal growth, toxin biosynthesis, and virulence. FgNup2 positively regulates H2Bub1 levels by facilitating the nuclear import of FgBre1, thereby influencing pathogenic development. The nuclear import of FgBre1 relies on the importin receptor FgImpα, and these two proteins interact. FgNup2, through a critical phenylalanine residue (F981) within its FG-repeat domain, promotes and stabilizes the FgImpα–FgBre1 complex, driving the assembly of the tripartite FgNup2–FgImpα–FgBre1 complex. This ultimately mediates the rapid nuclear translocation of FgBre1 under induction by the trichothecene biosynthesis-inducing medium. Our findings reveal a mechanism by which a nucleoporin regulates the nuclear entry of a histone-modifying enzyme via stabilizing the importin–cargo complex, advancing the understanding of non-canonical roles of the nuclear pore complex in pathogen adaptation. Author summary: Fusarium head blight, caused by the fungal pathogen F. graminearum, is a devastating disease that leads to significant wheat yield losses and contamination of grains with mycotoxins. The pathogenicity of this fungus is associated with the H2Bub1 modification, which is executed by the enzyme FgBre1. For FgBre1 to function, it must be imported into the nucleus. However, the regulatory mechanisms governing its nuclear import have remained unclear. Here, we identified FgNup2, a component of the nuclear pore complex, as a master regulator of fungal growth, toxin production, and the ability to infect wheat. Beyond serving as a passive gatekeeper, FgNup2 actively facilitates the nuclear entry of FgBre1. It acts as a molecular scaffold, stabilizing the interaction between FgBre1 and the nuclear transport shuttle protein FgImpα. Within FgNup2, the amino acid residue F981 was found to be critical for maintaining this stability. Our study reveals a mechanism by which a pathogen regulates key biological processes through modulating nuclear pore transport function, offering a novel target for developing intervention strategies aimed at curbing the virulence of this fungus.
SN - 1553-7374
ER -