Proteome analysis of the farnesol-induced stress response in Aspergillus nidulans—The role of a putative dehydrin

Dirk Wartenberg; Martin Vödisch; Olaf Kniemeyer; Daniela Albrecht-Eckardt; Kirstin Scherlach; Robert Winkler; Mirko Weide; Axel A. Brakhage

doi:10.1016/j.jprot.2012.05.023

Genome Wide Analysis Reveals the Role of VadA in Stress Response, Germination, and Sterigmatocystin Production in Aspergillus nidulans Conidia

Microorganisms ◽

10.3390/microorganisms8091319 ◽

2020 ◽

Vol 8 (9) ◽

pp. 1319 ◽

Cited By ~ 1

Author(s):

Ye-Eun Son ◽

Hee-Soo Park

Keyword(s):

Stress Response ◽

Secondary Metabolism ◽

Aspergillus Nidulans ◽

Gene Clusters ◽

Tube Formation ◽

Spore Viability ◽

Genetic Changes ◽

Genome Wide ◽

Trehalose Biosynthesis

In the Aspergillus species, conidia are asexual spores that are infectious particles responsible for propagation. Conidia contain various mycotoxins that can have detrimental effects in humans. Previous study demonstrated that VadA is required for fungal development and spore viability in the model fungus Aspergillus nidulans. In the present study, vadA transcriptomic analysis revealed that VadA affects the mRNA expression of a variety of genes in A. nidulans conidia. The genes that were primarily affected in conidia were associated with trehalose biosynthesis, cell-wall integrity, stress response, and secondary metabolism. Genetic changes caused by deletion of vadA were related to phenotypes of the vadA deletion mutant conidia. The deletion of vadA resulted in increased conidial sensitivity against ultraviolet stress and induced germ tube formation in the presence and absence of glucose. In addition, most genes in the secondary metabolism gene clusters of sterigmatocystin, asperfuranone, monodictyphenone, and asperthecin were upregulated in the mutant conidia with vadA deletion. The deletion of vadA led to an increase in the amount of sterigmatocystin in the conidia, suggesting that VadA is essential for the repression of sterigmatocystin production in conidia. These results suggest that VadA coordinates conidia maturation, stress response, and secondary metabolism in A. nidulans conidia.

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Defining the transcriptional responses of Aspergillus nidulans to cation/alkaline pH stress and the role of the transcription factor SltA

10.1101/2020.04.16.044396 ◽

2020 ◽

Author(s):

Irene Picazo ◽

Oier Etxebeste ◽

Elena Requena ◽

Aitor Garzia ◽

Eduardo A. Espeso

Keyword(s):

Stress Response ◽

Aspergillus Nidulans ◽

Growth Conditions ◽

Positive Control ◽

Saline Stress ◽

Alkaline Ph ◽

Regulatory Pathway ◽

Transcriptional Responses ◽

Regulatory Pathways

AbstractFungi have developed the ability to overcome extreme growth conditions and thrive in hostile environments. The model fungus Aspergillus nidulans tolerates, for example, ambient alkalinity up to pH 10 or molar concentrations of multiple cations. The ability to grow under alkaline pH or saline stress depends on the effective function of, at least, three regulatory pathways mediated by high hierarchy zinc-finger transcription factors: PacC, which mediates the ambient pH regulatory pathway, the calcineurin-dependent CrzA and the cation-homeostasis responsive factor SltA. Using RNA sequencing, we determined the effect of external pH alkalinisation or sodium stress on gene expression. Data show that each condition triggers transcriptional responses with a low degree of overlap. By sequencing the transcriptomes of the null mutant, the role of SltA in the abovementioned homeostasis mechanisms was also studied. Results show that the transcriptional role of SltA is wider than initially expected and implies, for example, the positive control of the PacC-dependent ambient pH regulatory pathway. Overall, our data strongly suggest that the stress-response pathways in fungi include some common but mostly exclusive constituents, and that there is a hierarchy of authority among the main regulators of stress response, with SltA controlling pacC expression at least in A. nidulans.

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Defining the transcriptional responses of Aspergillus nidulans to cation/alkaline pH stress and the role of the transcription factor SltA

Microbial Genomics ◽

10.1099/mgen.0.000415 ◽

2020 ◽

Vol 6 (8) ◽

Cited By ~ 1

Author(s):

Irene Picazo ◽

Oier Etxebeste ◽

Elena Requena ◽

Aitor Garzia ◽

Eduardo Antonio Espeso

Keyword(s):

Transcription Factor ◽

Stress Response ◽

Aspergillus Nidulans ◽

Growth Conditions ◽

Saline Stress ◽

Alkaline Ph ◽

Regulatory Pathway ◽

Transcriptional Responses ◽

Regulatory Pathways

Fungi have developed the ability to overcome extreme growth conditions and thrive in hostile environments. The model fungus Aspergillus nidulans tolerates, for example, ambient alkalinity up to pH 10 or molar concentrations of multiple cations. The ability to grow under alkaline pH or saline stress depends on the effective function of at least three regulatory pathways mediated by the zinc-finger transcription factor PacC, which mediates the ambient pH regulatory pathway, the calcineurin-dependent CrzA and the cation homeostasis responsive factor SltA. Using RNA sequencing, we determined the effect of external pH alkalinization or sodium stress on gene expression. The data show that each condition triggers transcriptional responses with a low degree of overlap. By sequencing the transcriptomes of the null mutant, the role of SltA in the above-mentioned homeostasis mechanisms was also studied. The results show that the transcriptional role of SltA is wider than initially expected and implies, for example, the positive control of the PacC-dependent ambient pH regulatory pathway. Overall, our data strongly suggest that the stress response pathways in fungi include some common but mostly exclusive constituents, and that there is a hierarchical relationship among the main regulators of stress response, with SltA controlling pacC expression, at least in A. nidulans.

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Conventional and novel PKC isoenzymes modify the heat-induced stress response but are not activated by heat shock

Journal of Cell Science ◽

10.1242/jcs.111.22.3357 ◽

1998 ◽

Vol 111 (22) ◽

pp. 3357-3365 ◽

Cited By ~ 1

Author(s):

C.I. Holmberg ◽

P.M. Roos ◽

J.M. Lord ◽

J.E. Eriksson ◽

L. Sistonen

Keyword(s):

Stress Response ◽

Heat Shock ◽

Heat Shock Response ◽

Mammalian Cells ◽

Elevated Temperatures ◽

Heat Shock Element ◽

Post Translational Modifications ◽

Induced Stress ◽

Shock Response

In mammalian cells, the heat-induced stress response is mediated by the constitutively expressed heat shock transcription factor 1 (HSF1). Upon exposure to elevated temperatures, HSF1 undergoes several post-translational modifications, including inducible phosphorylation or hyperphosphorylation. To date, neither the role of HSF1 hyperphosphorylation in regulation of the transcriptional activity of HSF1 nor the signaling pathways involved have been characterized. We have previously shown that the protein kinase C (PKC) activator, 12-O-tetradecanoylphorbol 13-acetate (TPA), markedly enhances the heat-induced stress response, and in the present study we elucidate the mechanism by which PKC activation affects the heat shock response in human cells. Our results show that several conventional and novel PKC isoenzymes are activated during the TPA-mediated enhancement of the heat shock response and that the enhancement can be inhibited by the specific PKC inhibitor bisindolylmaleimide I. Furthermore, the potentiating effect of TPA on the heat-induced stress response requires an intact heat shock element in the hsp70 promoter, indicating that PKC-responsive pathways are able to modulate the activity of HSF1. We also demonstrate that PKC is not activated by heat stress per se. These results reveal that PKC exhibits a significant modulatory role of the heat-induced stress response, but is not directly involved in regulation of the heat shock response.

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