It was concluded that elevated TrrA expression was consistent with an activated thioredoxin (Trx) system and that cross talk between the GSH and Trx dependent was evident in the absence of glrA. Moreover, depleted H2O2 levels in A. nidulansΔglrA were due to the observed elevation in catalase B and cytochrome c peroxidase levels. Significant upregulation
of an elongation factor 1β (ElfA; 2.5-fold) and a glutathione s-transferase (GstB; 2.6-fold) was also observed in A. nidulansΔglrA. Relevantly, orthologues of both of these proteins had previously been shown to be present and upregulated in response to oxidative stress in A. fumigatus (Burns et al., 2005; Carberry et al., 2006). Thön et al. DAPT clinical trial (2010) observed that the deletion of hapC, a component of the transcriptional regulator AnCF that senses the cellular redox status and coordinates the oxidative stress response, resulted in an impaired oxidative stress response. Characterization of the A. nidulansΔhapC proteome
identified upregulation of a range of redox-active proteins including thioredoxin, peroxiredoxin A and glutathione, compared with the wild type. Pusztahelyi et al. (2011) investigated the A. nidulans proteome, compared with transcriptomic alterations, during long-term exposure to menadione to further exploit the power of comparative proteomics for cellular redox investigations. Lessing et al. (2007) Selleck GSK2118436 used comparative proteomics to explore CHIR-99021 solubility dmso the effect of H2O2 on, and the deletion of a potential transcription factor Afyap1, involved in the oxidative stress response, from A. fumigatus. Differential gel electrophoresis (DIGE) analysis, followed by MALDI-ToF/ToF MS identified 27 and 17 proteins, respectively, whose expression was up- and downregulated (>1.5-fold cut-off) following A. fumigatus exposure to H2O2 (2 mM). Predominant among upregulated proteins were the Allergen Asp f3 (× 10-fold), a mitochondrial
peroxredoxin, Prx1 (× 3.7) and Cu,Zn superoxide dismutase (SOD; × 1.2–2.7). The authors proposed that given the classification of Asp f3 and Prx-1 as thioredoxin peroxidases, an elevation in thioredoxin system activity in response to oxidative stress is of significant importance in A. fumigatus. The altered expression of a range of metabolic enzymes was also evident and some proteins appeared in more than one gel spot, at identical Mr, but with an altered pI and amount. Lessing and colleagues speculated that this was due to either posttranslational modification or isoenzyme occurrence; either way, it revealed a type of information that can only be derived from proteomic, and not microarray, expression analyses. Of three unclassified proteins, or UFPs, the expression of two was downregulated (an NAD-dependent dehydrogenase and a UGP-1 protein), while one, a GMC oxidoreductase, was significantly upregulated (× 6.2).