scholarly journals The bZIP transcription factor Afap1 mediates the oxidative stress response and aflatoxin biosynthesis in Aspergillus flavus

2019 ◽  
Vol 51 (4) ◽  
pp. 292-301 ◽  
Author(s):  
Xuanli Guan ◽  
Yueju Zhao ◽  
Xiao Liu ◽  
Bo Shang ◽  
Fuguo Xing ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Transcription Factor ◽  
Stress Response ◽  
Aspergillus Flavus ◽  
Oxidative Stress Response ◽  
Bzip Transcription Factor ◽  
Aflatoxin Biosynthesis

scholarly journals The bZIP Transcription Factor AflRsmA Regulates Aflatoxin B1 Biosynthesis, Oxidative Stress Response and Sclerotium Formation in Aspergillus flavus

Toxins ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 271
Author(s):  
Xiuna Wang ◽  
Wenjie Zha ◽  
Linlin Liang ◽  
Opemipo Esther Fasoyin ◽  
Lihan Wu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Transcription Factor ◽  
Stress Response ◽  
Secondary Metabolites ◽  
Secondary Metabolism ◽  
Aspergillus Flavus ◽  
Aflatoxin B1 ◽  
Opportunistic Pathogen ◽  
Oxidative Stress Response ◽  
Bzip Transcription Factor

Fungal secondary metabolites play important roles not only in fungal ecology but also in humans living as beneficial medicine or harmful toxins. In filamentous fungi, bZIP-type transcription factors (TFs) are associated with the proteins involved in oxidative stress response and secondary metabolism. In this study, a connection between a bZIP TF and oxidative stress induction of secondary metabolism is uncovered in an opportunistic pathogen Aspergillus flavus, which produces carcinogenic and mutagenic aflatoxins. The bZIP transcription factor AflRsmA was identified by a homology research of A. flavus genome with the bZIP protein RsmA, involved in secondary metabolites production in Aspergillus nidulans. The AflrsmA deletion strain (ΔAflrsmA) displayed less sensitivity to the oxidative reagents tert-Butyl hydroperoxide (tBOOH) in comparison with wild type (WT) and AflrsmA overexpression strain (AflrsmAOE), while AflrsmAOE strain increased sensitivity to the oxidative reagents menadione sodium bisulfite (MSB) compared to WT and ΔAflrsmA strains. Without oxidative treatment, aflatoxin B1 (AFB1) production of ΔAflrsmA strains was consistent with that of WT, but AflrsmAOE strain produced more AFB1 than WT; tBOOH and MSB treatment decreased AFB1 production of ΔAflrsmA compared to WT. Besides, relative to WT, ΔAflrsmA strain decreased sclerotia, while AflrsmAOE strain increased sclerotia. The decrease of AFB1 by ΔAflrsmA but increase of AFB1 by AflrsmAOE was on corn. Our results suggest that AFB1 biosynthesis is regulated by AflRsmA by oxidative stress pathways and provide insights into a possible function of AflRsmA in mediating AFB1 biosynthesis response host defense in pathogen A. flavus.

scholarly journals The bZIP Transcription Factor Fgap1 Mediates Oxidative Stress Response and Trichothecene Biosynthesis But Not Virulence in Fusarium graminearum

PLoS ONE ◽  
2013 ◽  
Vol 8 (12) ◽  
pp. e83377 ◽  
Author(s):  
Mathilde Montibus ◽  
Christine Ducos ◽  
Marie-Noelle Bonnin-Verdal ◽  
Jorg Bormann ◽  
Nadia Ponts ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Transcription Factor ◽  
Stress Response ◽  
Fusarium Graminearum ◽  
Oxidative Stress Response ◽  
Bzip Transcription Factor

scholarly journals The bZIP transcription factor PsBZP32 is involved in cyst germination, oxidative stress response, and pathogenicity of Phytophthora sojae

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Yuting Sheng ◽  
Long Lin ◽  
Han Chen ◽  
Tianhuizi Pu ◽  
Xiaoyun Liu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Transcription Factor ◽  
Stress Response ◽  
Plant Pathogens ◽  
Oxidative Stress Response ◽  
Phytophthora Sojae ◽  
Bzip Transcription Factor ◽  
Transcription Level ◽  
A Genome ◽  
Cyst Germination

AbstractThe basic leucine zipper (bZIP) transcription factor family, one of the largest and most diverse transcription factor families in eukaryotes, is associated with the development and stress responses of many eukaryotic organisms. However, their biological functions in oomycete plant pathogens are unclear. A genome-wide analysis of bZIP transcription factors in Phytophthora sojae showed that PsBZP32, which has a unique bZIP-PAS domain structure, exhibited a high transcription level during the early stages of P. sojae infection. We silenced PsBZP32 in P. sojae and found that the transformants showed defective cyst germination and pathogenicity. The transformants could not eliminate host-derived reactive oxygen species during infection and were more sensitive to oxidative stress. Their response to oxidative stress was independent of the PsBZP32 transcription level; however, subcellular localization and phosphorylation of PsBZP32 were affected by H2O2 stress. These results indicate that PsBZP32 is involved in regulation of P. sojae cyst germination, oxidative stress response, and pathogenicity.

scholarly journals The bZip Transcription Factor Cap1p Is Involved in Multidrug Resistance and Oxidative Stress Response inCandida albicans

1999 ◽  
Vol 181 (3) ◽  
pp. 700-708 ◽  
Author(s):  
Anne-Marie Alarco ◽  
Martine Raymond
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Transcription Factor ◽  
Multidrug Resistance ◽  
Stress Response ◽  
Oxidative Stress Response ◽  
Bzip Transcription Factor ◽  
Term Therapy ◽  
Pathogenic Yeast ◽  
And Oxidative Stress

ABSTRACT Candida albicans is an opportunistic pathogenic yeast which frequently develops resistance to the antifungal agent fluconazole (FCZ) in patients undergoing long-term therapy. FCZ-resistant strains often display a reduced intracellular FCZ accumulation which correlates with the overexpression of the ATP-binding cassette transporters CDR1 and CDR2or the major facilitator (MF) MDR1. We have recently cloned a C. albicans gene, named CAP1, which codes for a bZip transcription factor of the AP-1 family homologous to the Yap1 protein involved in multidrug resistance and response to oxidative stress in Saccharomyces cerevisiae. CAP1 was found to confer FCZ resistance in S. cerevisiae by transcriptionally activating FLR1, a gene coding for an MF homologous to theC. albicans MDR1 gene product (A.-M. Alarco, I. Balan, D. Talibi, N. Mainville, and M. Raymond, J. Biol. Chem. 272:19304–19313, 1997). To study the role of CAP1 inC. albicans, we constructed a CAI4-derived mutant strain carrying a homozygous deletion of the CAP1 gene (CJD21). We found that deletion of CAP1 did not affect the susceptibility of CJD21 cells to FCZ, cerulenin, brefeldin A, and diamide but caused hypersensitivity to cadmium, 4-nitroquinolineN-oxide, 1,10-phenanthroline, and hydrogen peroxide, an effect which was reverted by reintroduction of the CAP1gene in these cells. Introduction of a hyperactive truncated allele ofCAP1 (CAP1-TR) in CJD21 resulted in resistance of the cells to all of the above compounds except hydrogen peroxide. The hyperresistant phenotype displayed by the CJD21 CAP1-TRtransformants was found to correlate with the overexpression of a number of potential CAP1 transcriptional targets such asMDR1, CaYCF1, CaGLR1, andCaTRR1. Taken together, our results demonstrate thatCAP1 is involved in multidrug resistance and oxidative stress response in C. albicans. Finally, disruption ofCAP1 in strain FR2, selected in vitro for FCZ resistance and constitutively overexpressing MDR1, did not suppress but rather increased the levels of MDR1 expression, demonstrating that CAP1 acts as a negative transcriptional regulator of the MDR1 gene in FR2 and is not responsible for MDR1 overexpression in this strain.

scholarly journals PICH, an ATP-dependent chromatin remodeling protein, transcriptionally co-regulates oxidative stress response.

2021 ◽  
Author(s):  
Anindita Dutta ◽  
Apurba Das ◽  
Deep Bisht ◽  
Vijendra Arya ◽  
Rohini Muthuswami
Keyword(s):  
Oxidative Stress ◽  
Transcription Factor ◽  
Transcriptional Regulation ◽  
Stress Response ◽  
Chromatin Remodeling ◽  
Dna Sequences ◽  
Target Genes ◽  
Antioxidant Response ◽  
Oxidative Stress Response ◽  
Antioxidant Genes

Cells respond to oxidative stress by elevating the levels of antioxidants, signaling, and transcriptional regulation often implemented by chromatin remodeling proteins.  The study presented in this paper shows that the expression of PICH, an ATP-dependent chromatin remodeler, is upregulated during oxidative stress in HeLa cells. We also show that PICH regulates the expression of Nrf2, a transcription factor regulating antioxidant response, both in the absence and presence of oxidative stress. In turn, Nrf2 regulates the expression of PICH in the presence of oxidative stress. Both PICH and Nrf2 together regulate the expression of antioxidant genes and this transcriptional regulation is dependent on the ATPase activity of PICH. In addition, H3K27ac modification also plays a role in activating transcription in the presence of oxidative stress. Co-immunoprecipitation experiments show that PICH and Nrf2 interact with H3K27ac in the presence of oxidative stress. Mechanistically, PICH recognizes ARE sequences present on its target genes and introduces a conformational change to the DNA sequences leading us to hypothesize that PICH regulates transcription by remodeling DNA. PICH ablation leads to reduced expression of Nrf2 and impaired antioxidant response leading to increased ROS content, thus, showing PICH is essential for the cell to respond to oxidative stress.

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