Calcineurin-Responsive Transcription Factor CgCrzA Is Required for Cell Wall Integrity and Infection-Related Morphogenesis in Colletotrichum gloeosporioides

ABSTRACT The Mpk1 mitogen-activated protein kinase (MAPK) of the cell wall integrity signaling pathway uses a noncatalytic mechanism to activate the SBF (Swi4/Swi6) transcription factor. Active Mpk1 forms a complex with Swi4, the DNA-binding subunit of SBF, conferring the ability to bind DNA. Because SBF activation is independent of Mpk1 catalytic activity but requires Mpk1 to be in an active conformation, we sought to understand how Mpk1 interacts with Swi4. Mutational analysis revealed that binding and activation of Swi4 by Mpk1 requires an intact D-motif-binding site, a docking surface common to MAPKs that resides distal to the phosphorylation loop but does not require the substrate-binding site, revealing a novel mechanism for MAPK target regulation. Additionally, we found that Mpk1 binds near the autoinhibitory C terminus of Swi4, suggesting an activation mechanism in which Mpk1 substitutes for Swi6 in promoting Swi4 DNA binding. Finally, we show that caffeine is an atypical activator of cell wall integrity signaling, because it induces phosphorylation of the Mpk1 C-terminal extension at Ser423 and Ser428. These phosphorylations were dependent on the DNA damage checkpoint kinases, Mec1/Tel1 and Rad53. Phosphorylation of Ser423 specifically blocked SBF activation by preventing Mpk1 association with Swi4, revealing a novel mechanism for regulating MAPK target specificity.

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The MAPKKK CgMck1 Is Required for Cell Wall Integrity, Appressorium Development, and Pathogenicity in Colletotrichum gloeosporioides

Genes ◽

10.3390/genes9110543 ◽

2018 ◽

Vol 9 (11) ◽

pp. 543 ◽

Cited By ~ 4

Author(s):

Yu-Lan Fang ◽

Li-Ming Xia ◽

Ping Wang ◽

Li-Hua Zhu ◽

Jian-Ren Ye ◽

...

Keyword(s):

Cell Wall ◽

Vegetative Growth ◽

Colletotrichum Gloeosporioides ◽

Mapk Signaling ◽

Cell Wall Integrity ◽

Mitogen Activated Protein Kinase ◽

Extracellular Signals ◽

Mapk Cascades ◽

Body Development ◽

Mitogen Activated Protein

Mitogen-activated protein kinase (MAPK) signaling pathway plays key roles in sensing extracellular signals and transmitting them from the cell membrane to the nucleus in response to various environmental stimuli. A MAPKKK protein CgMck1 in Colletotrichum gloeosporioides was characterized. Phenotypic analyses of the ∆Cgmck1 mutant showed that the CgMck1 was required for vegetative growth, fruiting body development, and sporulation. Additionally, the CgMCK1 deletion mutant showed significant defects in cell wall integrity, and responses to osmotic stresses. The mutant abolished the ability to develop appressorium, and lost pathogenicity to host plants. The ∆Cgmck1 mutant also exhibited a higher sensitivity to antifungal bacterium agent Bacillus velezensis. The deletion mutants of downstream MAPK cascades components CgMkk1 and CgMps1 showed similar defects to the ∆Cgmck1 mutant. In conclusion, CgMck1 is involved in the regulation of vegetative growth, asexual development, cell wall integrity, stresses resistance, and infection morphogenesis in C. gloeosporioides.

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A SET domain-containing protein involved in cell wall integrity signaling and peroxisome biogenesis is essential for appressorium formation and pathogenicity of Colletotrichum gloeosporioides

Fungal Genetics and Biology ◽

10.1016/j.fgb.2020.103474 ◽

2020 ◽

Vol 145 ◽

pp. 103474

Author(s):

Xuanzhu Zhao ◽

Bozeng Tang ◽

Jie Xu ◽

Na Wang ◽

Zongshan Zhou ◽

...

Keyword(s):

Cell Wall ◽

Colletotrichum Gloeosporioides ◽

Cell Wall Integrity ◽

Peroxisome Biogenesis ◽

Set Domain ◽

Appressorium Formation

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MaAreB, a GATA Transcription Factor, Is Involved in Nitrogen Source Utilization, Stress Tolerances and Virulence in Metarhizium acridum

Journal of Fungi ◽

10.3390/jof7070512 ◽

2021 ◽

Vol 7 (7) ◽

pp. 512

Author(s):

Chaochuang Li ◽

Qipei Zhang ◽

Yuxian Xia ◽

Kai Jin

Keyword(s):

Cell Wall ◽

Transcription Factor ◽

Functional Characterization ◽

Turgor Pressure ◽

Nitrogen Utilization ◽

Cell Wall Integrity ◽

Homologous Proteins ◽

Calcofluor White ◽

Metarhizium Acridum ◽

Gata Transcription Factor

The nitrogen catabolite repression (NCR) pathway is involved in nitrogen utilization, in which the global GATA transcription factor AreA plays an indispensable role and has been reported in many fungi. However, relatively few studies are focused on AreB, another GATA transcription factor in the NCR pathway and the functions of AreB are largely unknown in entomopathogenic fungi. Here, we characterized MaAreB in the model entomopathogenic fungus Metarhizium acridum. Sequence arrangement found that MaAreB had a conserved GATA zinc finger DNA binding domain and a leucine zipper domain. Disruption of MaAreB affected the nitrogen utilization and led to decelerated conidial germination and hyphal growth, decreased conidial yield, and lower tolerances to UV-B irradiation and heat-shock. Furthermore, the MaAreB mutant (ΔMaAreB) exhibited increased sensitivity to CFW (Calcofluor white), decreased cell wall contents (chitin and β-1,3-glucan) and reduced expression levels of some genes related to cell wall integrity, indicating that disruption of MaAreB affected the cell wall integrity. Bioassays showed that the virulence of the ΔMaAreB strain was decreased in topical inoculation but not in intra-hemocoel injection. Consistently, deletion of MaAreB severely impaired the appressorium formation and reduced the turgor pressure of appressorium. These results revealed that MaAreB regulated fungal nitrogen utilization, cell wall integrity and biological control potential, which would contribute to the functional characterization of AreB homologous proteins in other insect fungal pathogens, and even filamentous fungi.

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Regulation of the yeast Rlm1 transcription factor by the Mpk1 cell wall integrity MAP kinase

Molecular Microbiology ◽

10.1046/j.1365-2958.2002.03198.x ◽

2002 ◽

Vol 46 (3) ◽

pp. 781-789 ◽

Cited By ~ 163

Author(s):

Un Sung Jung ◽

Andrew K. Sobering ◽

Martin J. Romeo ◽

David E. Levin

Keyword(s):

Cell Wall ◽

Transcription Factor ◽

Map Kinase ◽

Cell Wall Integrity

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Erratum: The MAPKKK CgMck1 Is Required for Cell Wall Integrity, Appressorium Development, and Pathogenicity in Colletotrichum gloeosporioides (Genes 2018, 9, 543).

Genes ◽

10.3390/genes10100819 ◽

2019 ◽

Vol 10 (10) ◽

pp. 819

Author(s):

Fang ◽

Xia ◽

Wang ◽

Zhu ◽

Ye ◽

...

Keyword(s):

Cell Wall ◽

Colletotrichum Gloeosporioides ◽

Cell Wall Integrity ◽

Appressorium Development

The authors wish to make the following correction to this paper [...]

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A novel transcription factor negatively regulates antioxidant response, cell wall integrity and virulence in the fungal insect pathogen, Beauveria bassiana

Environmental Microbiology ◽

10.1111/1462-2920.15397 ◽

2021 ◽

Author(s):

Xin Zhao ◽

Tingying Luo ◽

Shuaishuai Huang ◽

Ning Peng ◽

Ying Yin ◽

...

Keyword(s):

Cell Wall ◽

Transcription Factor ◽

Beauveria Bassiana ◽

Antioxidant Response ◽

Cell Wall Integrity ◽

Insect Pathogen

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CgEnd3 Regulates Endocytosis, Appressorium Formation, and Virulence in the Poplar Anthracnose Fungus Colletotrichum gloeosporioides

International Journal of Molecular Sciences ◽

10.3390/ijms22084029 ◽

2021 ◽

Vol 22 (8) ◽

pp. 4029

Author(s):

Xiaolian Wang ◽

Dongxiao Lu ◽

Chengming Tian

Keyword(s):

Cell Wall ◽

Calcium Signaling ◽

Colletotrichum Gloeosporioides ◽

Early Stage ◽

Turgor Pressure ◽

Cell Wall Integrity ◽

Economic Losses ◽

Appressorium Formation ◽

Independent Manner ◽

Penetration Ability

The hemibiotrophic ascomycete fungus Colletotrichum gloeosporioides is the causal agent of anthracnose on numerous plants, and it causes considerable economic losses worldwide. Endocytosis is an essential cellular process in eukaryotic cells, but its roles in C. gloeosporioides remain unknown. In our study, we identified an endocytosis-related protein, CgEnd3, and knocked it out via polyethylene glycol (PEG)-mediated protoplast transformation. The lack of CgEnd3 resulted in severe defects in endocytosis. C. gloeosporioides infects its host through a specialized structure called appressorium, and ΔCgEnd3 showed deficient appressorium formation, melanization, turgor pressure accumulation, penetration ability of appressorium, cellophane membrane penetration, and pathogenicity. CgEnd3 also affected oxidant adaptation and the expression of core effectors during the early stage of infection. CgEnd3 contains one EF hand domain and four calcium ion-binding sites, and it is involved in calcium signaling. A lack of CgEnd3 changed the responses to cell-wall integrity agents and fungicide fludioxonil. However, CgEnd3 regulated appressorium formation and endocytosis in a calcium signaling-independent manner. Taken together, these results demonstrate that CgEnd3 plays pleiotropic roles in endocytosis, calcium signaling, cell-wall integrity, appressorium formation, penetration, and pathogenicity in C. gloeosporioides, and it suggests that CgEnd3 or endocytosis-related genes function as promising antifungal targets.

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The Late S-Phase Transcription Factor Hcm1 Is Regulated through Phosphorylation by the Cell Wall Integrity Checkpoint

Molecular and Cellular Biology ◽

10.1128/mcb.00952-15 ◽

2016 ◽

Vol 36 (6) ◽

pp. 941-953 ◽

Cited By ~ 7

Author(s):

Takahiro Negishi ◽

Jiri Veis ◽

David Hollenstein ◽

Mizuho Sekiya ◽

Gustav Ammerer ◽

...

Keyword(s):

Cell Cycle ◽

Cell Wall ◽

Transcription Factor ◽

Protein Level ◽

Budding Yeast ◽

Mapk Signaling ◽

S Phase ◽

Cell Wall Integrity ◽

Mitogen Activated Protein Kinase ◽

Mass Spectrometry Analysis

The cell wall integrity (CWI) checkpoint in the budding yeastSaccharomyces cerevisiaecoordinates cell wall construction and cell cycle progression. In this study, we showed that the regulation of Hcm1, a late-S-phase transcription factor, arrests the cell cycle via the cell wall integrity checkpoint. Although theHCM1mRNA level remained unaffected when the cell wall integrity checkpoint was induced, the protein level decreased. The overproduction of Hcm1 resulted in the failure of the cell wall integrity checkpoint. We identified 39 Hcm1 phosphorylation sites, including 26 novel sites, by tandem mass spectrometry analysis. A mutational analysis revealed that phosphorylation of Hcm1 at S61, S65, and S66 is required for the proper onset of the cell wall integrity checkpoint by regulating the timely decrease in its protein level. Hyperactivation of the CWI mitogen-activated protein kinase (MAPK) signaling pathway significantly reduced the Hcm1 protein level, and the deletion of CWI MAPK Slt2 resulted in a failure to decrease Hcm1 protein levels in response to stress, suggesting that phosphorylation is regulated by CWI MAPK. In conclusion, we suggest that Hcm1 is regulated negatively by the cell wall integrity checkpoint through timely phosphorylation and degradation under stress to properly control budding yeast proliferation.

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