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Displaying One Session

Plenary
Location
Ballroom B 3rd Floor
Date
07/20/2018
Time
11:00 AM - 12:00 PM
Plenary

ROS Signaling and Fungal Development

Session Number
Pl-5
Location
Ballroom B 3rd Floor, Puerto Rico Convention Center, San Juan, Puerto Rico
Date
07/20/2018
Time
11:00 AM - 12:00 PM
Authors
  • J. Aguirre
  • A. Mendoza-Martínez,
  • F. Lara-Rojas
  • O. Sanchez

Abstract

Abstract

Cells evolved mechanisms not only to defend themselves from reactive oxygen species (ROS) but also to use ROS as growth and cell differentiation signaling molecules. Using Aspergillus nidulans as model system, we have shown that transcription factors (TF) SrrA, NapA and AtfA are individually required to survive oxidative stress and that they also regulate asexual and sexual development. Aspergillus nidulans transcription factor (TF) NapA is a member of AP-1 family, which includes fungal Yap1 and Pap1 TFs. Just like Yap1 and Pap1 orthologs, NapA accumulates in the nucleus in presence of H2O2, a behavior also observed in the presence of menadione, osmotic stress or glucose starvation. NapA is essential for H2O2 resistance and normal production of conidia, while, it represses sexual development and regulates cleistothecia pigmentation. By showing that ∆napA mutants are unable to grow in arabinose, fructose and ethanol, we uncovered a novel role for NapA in carbon utilization. This is consistent with a transcriptomic analysis showing that during conidial development NapA is required for the regulation of at least 214 genes, including ethanol utilization genes alcR, alcA and aldA, as well as other genes involved in carbohydrate utilization, transcriptional regulation, drug detoxification and secondary metabolism. Peroxiredoxins are enzymes belonging to a conserved family of peroxidases that have been involved in H2O2 sensing and Yap1 and Pap1 activation. The phenotypic characterization of ∆gpxA, ∆tpxA, and ∆tpxB single, double and triple peroxiredoxin mutants in wild type or ∆napA backgrounds shows that none of these Prxs is required for NapA function in H2O2 or menadione resistance. However, these Prxs participate in a minor NapA-independent H2O2 resistance pathway, while NapA and TpxA appear to regulate conidiation along the same route. While all these peroxiredoxins are not necessary for arabinose and fructose utilization, TpxA and TpxB are important for ethanol utilization, suggesting that the utilization of this carbon source involves a specific type of oxidative stress.

Abstract

Aspergillus nidulans as model system, we have shown that transcription factors (TF) SrrA, NapA and AtfA are individually required to survive oxidative stress and that they also regulate asexual and sexual development. Aspergillus nidulans transcription factor (TF) NapA is a member of AP-1 family, which includes fungal Yap1 and Pap1 TFs. Just like Yap1 and Pap1 orthologs, NapA accumulates in the nucleus in presence of H2O2, a behavior also observed in the presence of menadione, osmotic stress or glucose starvation. NapA is essential for H2O2 resistance and normal production of conidia, while, it represses sexual development and regulates cleistothecia pigmentation. By showing that ∆napA mutants are unable to grow in arabinose, fructose and ethanol, we uncovered a novel role for NapA in carbon utilization. This is consistent with a transcriptomic analysis showing that during conidial development NapA is required for the regulation of at least 214 genes, including ethanol utilization genes alcR, alcA and aldA, as well as other genes involved in carbohydrate utilization, transcriptional regulation, drug detoxification and secondary metabolism. Peroxiredoxins are enzymes belonging to a conserved family of peroxidases that have been involved in H2O2 sensing and Yap1 and Pap1 activation. The phenotypic characterization of ∆gpxA, ∆tpxA, and ∆tpxB single, double and triple peroxiredoxin mutants in wild type or ∆napA backgrounds shows that none of these Prxs is required for NapA function in H2O2 or menadione resistance. However, these Prxs participate in a minor NapA-independent H2O2 resistance pathway, while NapA and TpxA appear to regulate conidiation along the same route. While all these peroxiredoxins are not necessary for arabinose and fructose utilization, TpxA and TpxB are important for ethanol utilization, suggesting that the utilization of this carbon source involves a specific type of oxidative stress.
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