Project description:Programmed cell death is an event displayed by many different organisms along the evolutionary scale. In plants, it is necessary for development and for the hypersensitive response to stress or pathogenic infection. A common feature to programmed cell death among organisms is the mitochondria-to-cytosol translocation of cytochrome c. To understand the role of cytochrome c in the onset of plant programmed cell death, a proteomic approach based on affinity chromatography has been developed, using Arabidopsis cytochrome c as bait. Eleven putative, new cytochrome c partners have been identified. Nine of them bind the heme protein in plant protoplasts and in human cells, as a heterologous system, according to Bimolecular Fluorescence Complementation. The binding affinities and the kinetic rate constants of three cytochrome c - target complexes have been estimated by Surface Plasmon Resonance. Our data suggest that the role of cytochrome c as a programmed cell death-signaling messenger could be evolutionarily well-conserved. Data Processing & data analysis: Peptides were analyzed using a nanoliquid chromatography-MS/MS on an LTQ linear ion trap mass spectrometer (Thermo Electron San Jose, CA, USA). The mass spectrometer was operated in the data-dependent mode to automatically switch between full MS and MS/MS acquisition. The parameters for ion scanning were the following: Full-scan MS(400-1800 m/z) plus top seven peaks Zoom/MS/MS (isolation width 2 m/z), normalized collision energy 35%. The scanning was performed using a dynamic exclusion list (120s exclusion list size of 50). Peak lists from all MS/MS spectra were extracted from the Xcalibur RAW files using a freely available program DTAsupercharge v.1.19 (http://msquant.sourceforge.net/). MASCOT 2.1 was used to search the Uniprot_Arabidopsis protein database 100323 (90895 sequences). Database search parameters used were the following: trypsin as enzyme; peptide tolerance, 300ppm; fragment ion tolerance, 0.6 Da; missed cleavage sites,1; fixed modification, carbamidomethyl cysteine and variable modifications, methionine oxidation. In all protein identifications the probability scores were greater than the score fixed by MASCOT (30) as significant with a p-value <0.05.
Project description:Colonization of barley roots with the basidiomycete fungus Piriformospora indica enhances resistance against the leaf pathogen Blumeria graminis f.sp. hordei (Bgh). To identify genes involved in this mycorrhiza-induced systemic resistance, we used the Affymetrix Barley1 22K gene chip for leaf transcriptome analysis of P. indica-colonized and non-colonized barley plants 12, 24 and 96 hours post inoculation (hpi) with a compatible Bgh strain.
Project description:The cytochrome P450 limonene-6-hydroxylase (P450), cytochrome P450 reductase (CPR) and carveol dehydrogenase (CDH) were expressed in Escherichia coli for (−)-carvone production from (−)-limonene. The optimum ratio of enzyme expression to maximize (−)-carvone production was determined using the proteome analysis quantification concatamer (QconCAT) method.
Project description:Polyunsaturated fatty acids (PUFA) sensitize cells to ferroptotic cell death. In the study associated with this dataset, we used UACC257 as a model cell line (intrinsically resistant to ferroptosis) induced to be sensitive to ferroptosis with different PUFAs. We performed genome-wide CRISPR knockout screen to identify genes that mediate the sensitivity to ML210, a selective inhibitor of glutathione peroxidase 4 (GPX4) and a potent inducer of ferroptotic cell death. We identified cytochrome P450 oxidoreductase (POR, CYPOR) as a key player required for ferroptotic cell death among other genes.
Project description:The drug phenobarbital induces cytochrome P450 monooxygenase (P450) gene expression in many animals, but no changes in P450 expression, or expression of any detoxification genes, were observed in worker honey bees fed on phenobarbital-candy relative to bees fed plain candy. Keywords: Expression profiling by array
Project description:Many transcription factors (TFs) in animals bind to both DNA and mRNA, regulating transcription and mRNA turnover. However, whether plant TFs function at both the transcriptional and posttranscriptional levels remains unknown. The rice (Oryza sativa) bZIP TF AVRPIZ-T-INTERACTING PROTEIN 5 (APIP5) negatively regulates programmed cell death and blast resistance and is targeted by the effector AvrPiz-t of the blast fungus Magnaporthe oryzae. We demonstrate that the nuclear localization signal of APIP5 is essential for APIP5-mediated suppression of cell death and blast resistance. APIP5 directly targets two genes that positively regulate blast resistance: the cell wall-associated kinase gene OsWAK5 and the cytochrome P450 gene CYP72A1. APIP5 inhibits OsWAK5 expression and thus limits lignin accumulation; moreover, APIP5 inhibits CYP72A1 expression and thus limits reactive oxygen species production and defense compounds accumulation. Remarkably, APIP5 acts as an RNA binding protein to regulate mRNA turnover of the cell death- and defense-related genes OsLSD1 and OsRac1. Therefore, APIP5 plays dual roles, acting as TF to regulate gene expression in the nucleus and as an RNA-binding protein to regulate mRNA turnover in the cytoplasm, a previously unidentified regulatory mechanism of plant TFs at the transcriptional and posttranscriptional levels.
Project description:During stress, while global mRNA translation is reduced, specific stress-responsive transcripts are translated. How stress-responsive mRNAs are selectively translated is unknown. Ribosome modifications may facilitate selective translation of specific transcripts in different cell types under differing conditions. Here we identify METL-5 as a C. elegans N6-adenosine methyltransferase that methylates adenosine 1717 on 18S rRNA. METL-5 specifically enhances ribosomal binding and selective translation of a cytochrome P450 mRNA, cyp-29A3, whose protein product oxidizes the omega-3 polyunsaturated fatty acid (PUFA) eicosapentaenoic acid to eicosanoids, important signaling molecules in stress responses. In fact although mutant metl-5 C. elegans grow normally under homeostatic conditions, they are resistant to a variety of stresses, including heat shock, cold, oxidants and UV irradiation. metl-5 mutant worms have reduced overall lipid levels and of bioactive lipid eicosanoids. Moreover, dietary supplementation of eicosanoid products of CYP-29A3 restores stress sensitivity of metl-5 mutant worms. Thus methylation of a specific residue of 18S rRNA by METL-5 selectively enhances translation of cyp-29A3, to increase production of eicosanoids that increase stress-related death.
Project description:Microarray analysis to examine the relationship between hepatic phenotype and changes in gene expression in cytochrome P450 reductase (CPR) null mice. Keywords: ordered