Project description:A deletion variant of GmCGS2 was ectopically expressed in soybean with a diverse range of expression levels and patterns. A combination of a soybean ubiquitin promoter and an in-frame deletion in GmCGS2, from K66 to S143, resulted in increased seed Met and Cys contents without incurring a yield penalty in a ten-location field trial. Transgenic events of this construct had increases of 41 to 114%, 10 to 12%, and 4.7 to 7.3% in free Met, total Cys, and total Met, respectively. RNAseq analysis of developing seed revealed increased transcript for three Cys-rich Bowman-Birk protease inhibitor (BBI) genes, and for two Met-rich 2S albumin genes, with little effect apparent on genes of primary sulfur metabolism. Trypsin-agarose chromatography, protease inhibition assays, and mass spectrometry analysis revealed increased BBI and 2S albumin proteins. The additional BBI protein was determined to be 1.5 to 1.8% of the protein in transgenic seed, sufficient to account for the increased Cys content. The observation that overexpressing an enzyme involved in Met biosynthesis that used Cys as a substrate still increased total Cys more than total Met suggested a lack of native Met-rich soybean proteins capable of incorporating the additional free Met.
Project description:First experiment: Cells were cultured in sulfur amino acid-free DMEM supplemented with 0.1 mM methionine + 0.1 mM cysteine (complete) or supplemented only with 0.1 mM methionine (cysteine-free). Cells were cultured in either medium for 42 h (Long + Cys; Long -Cys) or in cysteine-free medium for 36 h followed by 6 h in complete medium (Short +Cys); Second experiment: C3A/HepG2 cells were cultured in sulfur amino acid-free DMEM supplemented with 0.1 mM Met and 0.1 mM Cys (complete) or supplemented only with 0.1 mM Met (cysteine-devoid). Cells were cultured in complete medium for 42 h (Long +Cys) or in complete medium for 36 h followed by cysteine-devoid medium for 6 h (Short -Cys). Experiment Overall Design: First experiment: Three plates of cells were cultured under each condition. Cells were cultured in sulfur amino acid-free DMEM supplemented with 0.1 mM methionine + 0.1 mM cysteine (complete) or supplemented only with 0.1 mM methionine (cysteine-free). Cells were cultured in either medium for 42 h (Long + Cys; Long -Cys) or in cysteine-free medium for 36 h followed by 6 h in complete medium (Short +Cys). Experiment Overall Design: Second experiment: C3A/HepG2 cells were cultured in sulfur amino acid-free DMEM supplemented with 0.1 mM Met and 0.1 mM Cys (complete) or supplemented only with 0.1 mM Met (cysteine-devoid). Cells were cultured in complete medium for 42 h (Long +Cys) or in complete medium for 36 h followed by cysteine-devoid medium for 6 h (Short -Cys).
Project description:First experiment: Cells were cultured in sulfur amino acid-free DMEM supplemented with 0.1 mM methionine + 0.1 mM cysteine (complete) or supplemented only with 0.1 mM methionine (cysteine-free). Cells were cultured in either medium for 42 h (Long + Cys; Long -Cys) or in cysteine-free medium for 36 h followed by 6 h in complete medium (Short +Cys) Second experiment: C3A/HepG2 cells were cultured in sulfur amino acid-free DMEM supplemented with 0.1 mM Met and 0.1 mM Cys (complete) or supplemented only with 0.1 mM Met (cysteine-devoid). Cells were cultured in complete medium for 42 h (Long +Cys) or in complete medium for 36 h followed by cysteine-devoid medium for 6 h (Short -Cys). Keywords: amino acid deprivation
Project description:We have previously shown that deprivation of essential amino acids, namely methionine/cysteine or tyrosine, leads to the transcriptional reactivation of integrated silenced transgenes, and latent HIV-1 provirus. In an effort to understand the underlying mechanisms, here we investigate the overall transcriptional profile of HeLa cells upon Met/Cys starvation for different time points, including the expression of repeated and transposable elements. HeLa cells carrying a stably integrated and silenced plasmid expressing the OA1/GPR143 gene (pcDNA3.1-OA1) were cultured in regular DMEM medium for 6-30-120 hours, or in absence of Met/Cys for 6-15-30-72-120 hours, and the changes in the expression of genes and repeated elements was evaluated by RNAseq
Project description:A Multiple Affinity Removal System (MARS) Human 14 spin cartridge was used to deplete a dolphin serum which was then digested with trypsin and analyzed without prior fractionation by nanoLC-MS/MS. These files are associated with "2011-9-25_Neely-DolphinSerum." Data analysis: raw data generated by the AB Sciex 5600 were converted to a peak list using the AB Sciex MS Data Converter (v. 1.1 beta, July 2011). Protein identifications were made using Mascot (v. 2.3.02) searching against the Ensembl (release 64) turTru1 dolphin genome assembly protein database [16,598 sequences] and the common Repository of Adventitious Proteins database (cRAP; 2012.01.01; the Global Proteome Machine) using the following parameters: trypsin was selected as the enzyme and three missed cleavages were allowed; carbamidomethylation (Cys) was specified as a fixed modification; glucosylgalactosyl (Lys), oxidation (Met, Pro), and 2-succinyl (Cys) were specified as variable modifications; a precursor tolerance of 10 ppm and fragment ion tolerance of 0.5 Da; instrument type was ESI-QUAD-TOF. Additionally, a non-depleted dolphin sera that had been digested followed by quasi-fractionation using SPE, was analyzed by nano-LC-MS/MS which lead to an additional peptide identification, KGEPGESAYVYR, and these files are associated with "2012-12-12 Dolphin IDA".
Project description:In the current study, we used a mass spectrometry-based redox proteomics approach to test responses of the cysteine (Cys) proteome to selective disruption of the Trx- and GSH-dependent systems. Auranofin (ARF) was used to inhibit Trx reductase without detectable oxidation of the GSH/GSSG couple, and buthionine sulfoximine (BSO) was used to deplete GSH without detectable oxidation of Trx1. Results for 606 Cys-containing peptides (peptidyl Cys) showed that 36% were oxidized over 1.3-fold by ARF, while BSO-induced oxidation of peptidyl Cys was only 10%. Mean fold oxidation of these peptides was also higher by ARF than BSO treatment. Analysis of potential functional pathways showed that ARF oxidized peptides associated with glycolysis, cytoskeleton remodeling, translation and cell adhesion. Of 60 peptidyl Cys oxidized due to depletion of GSH, 41 were also oxidized by ARF and included proteins of translation and cell adhesion but not glycolysis or cytoskeletal remodeling. Studies to test functional correlates showed that pyruvate kinase activity and lactate levels were decreased with ARF but not BSO, confirming the effects on glycolysis-associated proteins are sensitive to oxidation by ARF. These data show that the Trx system regulates a broader range of proteins than GSH system, support distinct function of Trx and GSH in cellular redox control, and show for the first time in mammalian cells selective targeting peptidyl Cys and biological pathways due to deficient function of the Trx system. ICAT-labeled Cys peptides were analyzed by reverse-phase liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Peptide eluents were monitored in an MS survey scan followed by ten data-dependent MS/MS scans on an LTQ-Orbitrap ion trap mass spectrometer (Thermo Finnigan, San Jose, CA). The LTQ was used to acquire MS/MS spectra (2 m/z isolation width, 35% collision energy, 5,000 AGC target, 200 ms maximum ion time). The Orbitrap was used to collect MS scans (300-1600 m/z, 1,000,000 AGC target, 500 ms maximum ion time, resolution 30,000). All data were converted from .raw files to the .dta format using ExtractMS version 2.0 (Thermo Finnigan, San Jose, CA). The acquired MS/MS spectra were searched against a concatenated target-decoy human RefSeq (release 37 - September 2009 - 38108 target proteins) database of the National Center for Biotechnology Information using the SEQUEST Sorcerer algorithm (version 3.11, SAGE-N) searching parameters included partially tryptic restriction, parent ion mass tolerance (+/- 20 ppm), dynamic modifications of oxidized Met (+15.9949 Da), differential ICAT-modified Cys (+9.0302 Da) and static ICAT modification of Cys (+227.1270 Da). The peptides were classified by charge state and tryptic state (fully and partial) and first filtered by mass accuracy (10 ppm for high-resolution MS), and then dynamically by increasing XCorr and deltaCn values to reduce protein false discovery rate to less than 1%, according to the target-decoy strategy.
Project description:Yeast protein microarrays were utilized to investigate determinants of S-nitrosylation by biologically relevant low-mass S-nitrosothiols (SNOs). Large numbers of S-nitrosylated yeast proteins were identified after treatment with SNOs, among which those with active-site Cys thiols residing at N termini of alpha-helices or within catalytic loops were particularly prominent. However, S-nitrosylation varied substantially even within these families of proteins (e.g., papain-related Cys-dependent hydrolases and rhodanese/Cdc25 phosphatases), suggesting that neither secondary structure nor intrinsic nucleophilicity of Cys thiols was sufficient to explain specificity. Further analyses revealed a substantial influence of NO-donor stereochemistry and structure on efficiency of S-nitrosylation as well as an unanticipated and important role for allosteric effectors. Thus, high-throughput screening and unbiased proteome coverage reveal multifactorial determinants of S-nitrosylation (which may be overlooked in alternative proteomic analyses), and support the idea that target specificity can be achieved through rational design of S-nitrosothiols
Project description:We surveyed the heterogeneity of the mitochondrial proteome and its function during a typical night and day cycle in Arabidopsis shoots. This used a staged, quantitative analysis of the proteome across 10 time points covering 24 h of the life of 3-week-old Arabidopsis shoots grown under 12-h dark and 12-h light conditions. Results were queried against an in-house Arabidopsis database comprising ATH1.pep (release 7) from The Arabidopsis Information Resource and the Arabidopsis mitochondrial and plastid protein sets (the combined database contained a total of 30,700 protein sequences with 12,656,682 residues) using the Mascot search engine version 2.2 and utilizing error tolerances of +-1.2 Da for MS and +-0.6 Da for MS/MS, 'enzyme' set to trypsin, 'maximum missed cleavages' set to 1, variable modifications of oxidation (Met) and carbamidomethyl (Cys), instrument set to ESI-TRAP, and peptide charge set at 2+ and 3+. ATH1.pep is a non-redundant database with systematically named protein sequences based on Arabidopsis genome sequencing and annotation. PRIDE XML files with accession numbers 10471–10525 and without peptide/protein identifications have already been made public.
Project description:The transcriptomic response to reduced expression of RER2 (orf19.4028) gene encoding for a main cis-prenyltransferase in Candida albicans was checked by using a microarray (Eurogentec, approx 98% coverage of genomic ORFs). The C. albicans wild type control strain and the PMET3RER2/rer2::hisG conditional mutant were grown for 16 h at 28 M-0C in SD medium in the presence of 2.5 mM Met/Cys.