Redox control of the cAMP/PKA pathway during protein misfolding stress
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ABSTRACT:
INSTRUMENT(S): Illumina HiSeq 2500
ORGANISM(S): Saccharomyces cerevisiae
SUBMITTER: Leo Zeef
PROVIDER: E-MTAB-9355 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:The pattern of gene transcription in Saccharomyces cerevisiae is strongly affected by the presence of glucose. An increased activity of protein kinase A (PKA), triggered by a rise in the intracellular concentration of cAMP, can account for many of the effects of glucose on transcription. To investigate the requirement of PKA for glucose control of gene expression, we have analyzed global transcription in strains devoid of PKA activity. In S. cerevisiae three genes, TPK1, TPK2, TPK3, encode catalytic subunits of PKA and the triple mutant tpk1 tpk2 tpk3 is unviable. We have worked, therefore, with two strains, tpk1 tpk2 tpk3 yak1 and tpk1 tpk2 tpk3 msn2 msn4, that bear suppressor mutations,. We have identified different classes of genes that can be induced, or repressed, by glucose in the absence of PKA. Among these genes, some are also controlled by a redundant signalling pathway involving PKA activation, while others do not respond to an increase in cAMP concentration. On the other hand, among genes which do not respond to glucose in the absence of PKA, some show a full response to increased cAMP levels, even in the absence of glucose, while others appear to require the cooperation of different signalling pathways. The goal of the present study was to investigate the occurrence of PKA-independent glucose signalling in S. cerevisiae. To this end, we have used global transcription analysis to study the effects of glucose on yeast strains completely devoid of PKA activity. In S. cerevisiae three genes TPK1, TPK2,and TPK3 encode catalytic subunits of PKA. While strains expressing only one of these genes grow normally, a triple null mutant (tpk1 tpk2 tpk3) is not viable (Toda et al 1987). Identification of different mutations able to suppress the growth defect of the triple mutant (Garrett and Broach 1989, Reinders et al 1998, Smith et al 1998) has allowed to determine what is the crucial function of PKA. As shown in Fig.1, PKA is needed to counteract the negative effect of the protein kinase Yak1 on yeast growth (Hartley et al 1994, Moriya et al 2001). In the presence of PKA the protein kinase Rim15 (Reinders et al 1998) and the transcription factors Msn2 and Msn4 (Görner et al 1998) can be phosphorylated and exported to the cytoplasm, transcription of the YAK1 gene, which is activated by Msn2/Msn4 (Smith et al 1998), is reduced, Yak1 levels remain low and growth is not hindered. In the absence of PKA, Rim15 remains in the nucleus where it can activate Msn2/Msn4 (Cameroni et al 2004) that turn on YAK1 transcription, thus blocking growth. This explains why strains lacking Rim15, Msn2/Msn4 or Yak1 no longer require PKA for growth. In this work we have used two isogenic strains lacking PKA and carrying the suppressor mutations msn2 msn4 or yak1. Two different suppressor mutants were used with the aim to enable a dissection of effects of the lack of PKA and effects of the suppressor mutations themselves.
2011-08-08 | E-GEOD-27541 | biostudies-arrayexpress
Project description:Thiol-dependent redox regulation is essential for the rapid adaptation of chloroplast metabolism to unpredictable changes of light intensity. The disulfide reductase activity of thioredoxins (Trxs), which relies on photo-reduced ferredoxin (Fdx) and a Fdx-dependent Trx reductase (FTR), constitutes the Fdx-FTR-Trxs system, which links chloroplast redox regulation to light. In addition, chloroplasts harbor an NADPH-dependent Trx reductase (NTR) with a joint Trx domain, NTRC. The activity of these two redox systems is integrated by the balance of the hydrogen peroxide scavenging enzyme 2-Cys peroxiredoxin (2-Cys Prx), which thus plays a key role in maintaining the reducing capacity of chloroplast Trxs in response to light intensity. Based on the severe phenotype of mutant lines lacking NTRC, it is clear that this enzyme plays an essential role in chloroplast redox homeostasis. However, whether the function of NTRC depends on its capacity of reduce 2-Cys Prxs or has additional targets remains unknown. Here, we have addressed this issue by a comparative analysis of the triple mutant of Arabidopsis thaliana, ntrc-2cpab, simultaneously lacking 2-Cys Prxs and NTRC, and the double mutant 2cpab lacking 2-Cys Prxs. The phenotype of the ntrc-2cpab mutant is indistinguishable of the 2cpab mutant, as shown by growth rate, photosynthesis performance, light-dependent redox regulation of enzyme activity and comparative transcriptomics based RNA-Seq. Based on these results, we propose that the function of NTRC in chloroplast redox homeostasis is exerted by the regulation of the redox balance of 2-Cys Prxs rather than by the direct reduction of additional targets.
2021-09-09 | GSE147793 | GEO
Project description:Peroxiredoxins are ubiquitous thiol-dependent peroxidases for which chaperone and signaling roles have been reported in various types of organisms in the last years. In plants, the peroxidase function of the two typical plastidial 2-Cys peroxiredoxins (2-Cys PRX A and B) has been highlighted while the other functions, particularly in ROS-dependent signal transduction pathways, are still elusive due notably to the lack of knowledge on interacting partners. Using an ex vivo approach based on co-immunoprecipitation of leaf extracts from Arabidopsis thaliana wild-type and mutant plants lacking 2-Cys PRX expression followed by mass spectrometry-based proteomics, 158 proteins were found associated to 2-Cys PRXs, notably already known partners like thioredoxin-related electron donors (Chloroplastic Drought-induced Stress Protein of 32 kDa, Atypical Cysteine Histidine rich Thioredoxin 2) and enzymes involved in chlorophyll synthesis (Protochlorophyllide OxidoReductase B) or carbon metabolisms (Fructose-1,6-BisPhosphatase), validating the relevance of this approach.
2016-10-11 | PXD003923 | Pride
Project description:Global restriction of protein synthesis is a hallmark of cellular stress. Using hydrogen peroxide, we monitor the transcript level and also the translation status for each RNA using cycloheximide to freeze elongating ribosomes. Polyribosome fractionation of cell extracts was used to separate highly translated and poorly translated mRNAs that were then separately analysed.
2006-06-01 | E-MEXP-526 | biostudies-arrayexpress
Project description:Msr1 and Mafb were identified as essential genes for the internalization of peroxiredoxin protein by this microarray analysis. We found that Msr1 and Mafb were deficient in mutant RAW lines. Overexpression of Msr1 or Mafb in mutant RAW cells regained the activity for the efficient internalization of peroxiredoxin protein.
2016-11-01 | GSE89329 | GEO
Project description:The redox-sensing MarR/DUF24-type repressor YodB controls expression of the azoreductase AzoR1 and the nitroreductase YodC that are involved in detoxification of quinones and diamide in Bacillus subtilis. In the present paper, we identified YodB and its paralog YvaP (CatR) as repressors of the yfiDE (catDE) operon encoding a catechol-2,3-dioxygenase that also contributes to quinone resistance. Inactivation of both paralogs, CatR and YodB, results in full derepression of catDE transcription. DNA-binding assays and promoter mutagenesis studies showed that CatR protects two inverted repeats with the consensus sequence TTAC-N5-GTAA overlapping the -35 promoter region (BS1) and the transcriptional start site (BS2). The BS1 operator was required for binding of YodB in vitro. CatR and YodB share the conserved N-terminal Cys residue that is essential for redox-sensing of CatR in vivo as shown by Cys-to-Ser mutagenesis. Our data suggest that CatR is modified by intermolecular disulfide formation in response to diamide and quinones in vitro and in vivo. Redox-regulation of CatR occurs independently of YodB and no protein interaction was detected between CatR and YodB in vivo using protein-crosslinking and mass spectrometry. Control of Bacillus subtilis 168 wild type (Ko_WT) vs. DyvaP mutant (Ko_DyvaP). The experiment was conducted in duplicates using two independent total RNA preparations. For all datasets used for final analysis, wild-type samples were labeled with Cy3 and DyvaP mutant samples were labeled with Cy5.
2010-06-29 | E-GEOD-22603 | biostudies-arrayexpress
Project description:Many 2-Cys-peroxiredoxins (2-Cys-Prxs) serve as dual-function proteins. Active as peroxidases under non-stress conditions, they convert into effective chaperones under stress conditions. While their peroxidase activity has been extensively studied and shown to involve cycles of redox-mediated oligomeric changes, the mechanisms by which 2-Cys-Prxs sense stress and convert into general chaperones remain to be defined. Here we focus on the Leishmania infantum mitochondrial 2-Cys-Prx (mTXNPx, Prx1m), which, in its reduced, decameric form, readily adopts chaperone function upon exposure to heat shock temperatures. This activity is crucial for parasite survival in mammalian hosts. Here we have determined the cryo-EM structure of mTXNPx in complex with a thermally unfolded client protein that identifies the flexible N-termini of mTXNPx to form a well-resolved central belt that contacts and encapsulates the unstructured client protein in the center of the decamer ring. In vivo cross-linking studies combined with quantitative in vitro cross-linking experiments further support these interactions, and demonstrate that mTXNPx decamers undergo substantial temperature-dependent structural rearrangements specifically at the dimer-dimer interfaces. These structural changes appear crucial for exposing chaperone client binding sites that are otherwise buried in the peroxidase-active protein. Based on this mechanism, we propose that mTXNPx is the founding member of heat-stress activated chaperones in parasitic mitochondria that facilitate the transition to warm-blooded host environments.
2019-02-19 | PXD010281 | Pride
Project description:Plant cells contain different O-acetylserine(thiol)lyase (OASTL) enzymes involved in Cys biosynthesis and located in different subcellular compartments. These enzymes are made up of a complex variety of isoforms resulting in different subcellular Cys pools. To unravel the contribution of cytosolic Cys to plant metabolism, we characterized the knockout oas-a1.1 and osa-a1.2 mutants, deficient in the most abundant cytosolic OASTL isoform in Arabidposis thaliana. Total intracellular Cys and glutathione concentrations were reduced, and the glutathione redox state was shifted in favour of its oxidized form. Interestingly, the capability of the mutants to chelate heavy metals did not differ from that of the wild type, but the mutants have an enhanced sensitivity to Cd. With the aim of establishing the metabolic network most influenced by the cytosolic Cys pool, we used the ATH1 GeneChip for evaluation of differentially expressed genes in the oas-a1.1 mutant grown under non-stress conditions. The transcriptomic footprints of mutant plants had predicted functions associated with various physiological responses that are dependent on reactive oxygen species and suggested that the mutant was oxidatively stressed. To further elucidate the specific function(s) of the OAS-A1 isoform in the adaptation response to cadmium we extended the trasncriptome experiment to the wild type and oas-a1.1 mutant plants exposed to Cd. The comparison of transcriptomic profiles showed a higher proportion of genes with altered expression in the mutant than in the wild type, highlighting up-regulated genes identified as of the general oxidative stress response rather than metal-responsive genes. Wild type and oas-a1.1 mutant plants were grown hydroponically and, after a two-week acclimation period, the roots and shoots were harvested separately. Total RNA was then prepared and analyzed using the Affymetrix-Arabidopsis ATH1GeneChip array. Three biological replicates were performed for each sample. We made two different comparisons to classify the differently expressed genes in the mutant plant: oas-a1.1 roots versus wild-type roots and oas-a1.1 shoots versus wild-type shoots. Hydroponically-grown wild type and oas-a1.1 mutant plants were further treated with 50µM CdCl2 and 18h-treated-roots and 24h-treated-shoots were harvested. Total RNA was then prepared and analyzed using the Affymetrix-Arabidopsis ATH1GeneChip array. Three biological replicates were performed for each sample. Different comparisons were performed as follows: 18h Cd-treated wild type roots versus untreated wild type roots; 24h Cd-treated wild type shoots versus untreated wild type shoots; 18h Cd-treated oas-a1.1 roots versus untreated oas-a1.1 roots; 24h Cd-treated oas-a1.1 shoots versus untreated oas-a1.1 shoots; 18h Cd-treated oas-a1.1 roots versus 18h Cd-treated wild type roots; 24h Cd-treated oas-a1.1 shoots versus 24h Cd-treated wild type shoots
2010-10-01 | E-GEOD-19245 | biostudies-arrayexpress
Project description:Protein S-thiolation is a post-translational thiol-modification that controls redox-sensing transcription factors and protects active site cysteine residues against irreversible oxidation. In B. subtilis, the MarR-type repressor OhrR was shown to sense organic hydroperoxides via formation of mixed disulfides with the redox buffer bacillithiol (Cys-GlcN-Malate) termed as S-bacillithiolation. We have studied changes in the transcriptome and redox proteome caused by the strong oxidant hypochloric acid (NaOCl), the active component of house-hold bleach. The OhrR-controlled peroxiredoxin OhrA was most strongly up-regulated by NaOCl stress and conferred specific protection against NaOCl. Inactivation of the OhrR repressor was caused by S-bacillithiolation of the redox-sensing Cys15 residue in response to NaOCl. Two cobalamin-independent methionine synthases MetE and YxjG were identified as S-bacillithiolated at their essential active site cysteines resulting in hypochlorite-induced methionine limitation. In summary, our studies show that S-bacillithiolation of OhrR and the methionine synthases is the major mechanism in protection against hypochlorite stress in B. subtilis. The B. subtilis 168 wild type strain was grown in minimal medium to OD500 of 0.4 and harvested before and 10 minutes after exposure to 50 µM NaOCl. Microarray hybridizations were performed in triplicate using RNA isolated from independent cultures.
2011-07-04 | E-GEOD-27637 | biostudies-arrayexpress
Project description:As a terpenoids natural product isolated from the plant Thunder God Vine, Celastrol is widely studied for its pharmacological activities, including anti-tumor activities. However, the clinical application of Celastrol is strictly limited due to its severe side effects. Without identification and validation of the target protein of Celastrol, it is difficult to determine whether its anti-tumor activities and side effects are due to inhibition of the same protein. Using a new computational tool we have developed for target discovery, peroxiredoxin I (PRDX1) was identified as the ROS-manipulating target protein of Celastrol. High-resolution crystal structure revealed the unique binding mode of Celastrol with PRDX1, via covalent reaction to the catalytic Cys-173 residue of PRDX1. New derivative compound named 19-048 with improved potency against PRDX1 and selectivity towards PRDX2~PRDX6 were synthesized. Both Celastrol and compound 19-048 effectively suppressed the proliferation of colorectal cancer cells. While these anti-tumor efficacy was significantly diminished on xenograft nude mice bearing PRDX1 knock-down colorectal cancer cells. Several downstream genes of p53 were dramatically up-regulated in the presence of Celastrol and compound 19-048. Our findings reveal that the side effects of Celastrol could be reduced via structural modification, and PRDX1 inhibition is promising for the treatment of colorectal cancer.
2022-12-31 | GSE198630 | GEO