Name: Ti4+-IMAC label-free quantification
Keywords: Label-free phosphoproteomics

Dataset Information

Ti4+-IMAC label-free quantification

ABSTRACT: We combine high-resolution mass spectrometry with Ti4+-IMAC phosphopeptide enrichment and label-free quantification to monitor the phosphoproteome of Jurkat T-cells following stimulation by Prostaglandin E2. Jurkat T lymphoma cells were grown in RPMI 1640 medium supplemented with 10% fetal bovine serum and penicillin/streptomycin (Lonza). For PGE2 stimulation, cells were centrifuged for 1 min at 1500g. The growth medium was removed and the cells were resuspended at a final concentration of 1-2 × 106 cells/ml in RMPI and supplemented with 0 (control) or 10 uM PGE2 and incubated for 5, 10, 20, 30 or 60 min. After cell lysis, reduction and alkylation, proteins were digested with Lys-C and Trypsin. The digests were desalted using Sep-Pak C18 cartridges, dried in vacuo and stored at −80 °C for further use. Phosphopeptide enrichment was performed as described in Zhou H, Ye M, Dong J, Corradini E, Cristobal A, Heck AJ, Zou H, Mohammed S. Nat Protoc. 2013 Mar;8(3):461-80. The enriched phosphopeptides were subjected to a reversed phase nano-LC–MS/MS analysis consisting of a Proxeon EASY-nLC 1000, an analytical column heater (40°C) and an LTQ-Orbitrap Elite. After the survey scans, the 20 most intense precursors were selected for subsequent CID or ETD-IT fragmentation. A programmed data-dependent decision tree determined the choice of the most appropriate technique for a selected precursor. In essence, doubly charged peptides were subjected to CID fragmentation and more highly charged peptides were fragmented using ETD. Raw data were processed with MaxQuant version 1.3.0.523, and the peptides were identified from the MS and MS/MS spectra searched against a concatenated forward-decoy Swissprot Homo sapiens database version 2012_09 (40,992 sequences) using the Andromeda search engine. The database search was performed with the following parameters: an initial mass tolerance of ±20 ppm for precursor masses; final mass tolerance of ±6 ppm: ±0.6 Da for CID and ETD-ion trap fragment ions, allowing two missed cleavages. Cysteine carbamidomethylation was used as a fixed modification and methionine oxidation, protein N-terminal acetylation and serine, threonine and tyrosine phosphorylation as variable modifications. For the identification, the false discovery rate was set to 0.01 for peptides, proteins and sites and the minimum peptide length allowed was six amino acids and a minimum peptide score of 60. The match between run feature was set on. A site localization probability of at least 0.75 and a score difference of at least 5 were used as threshold for the phosphoresidue localization. Normalization was performed by subtracting the median of log transformed intensities for each LC-MS/MS run.

REANALYSED by: PAe005135PAe005134PAe005133PAe005124

INSTRUMENT(S): LTQ Orbitrap Elite

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Cell Suspension Culture, T Cell, Cell Culture

SUBMITTER: Piero Giansanti

LAB HEAD: Albert J. R. Heck

PROVIDER: PXD000293 | Pride | 2014-05-22

REPOSITORIES: Pride

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Publications

Single-step enrichment by Ti4+-IMAC and label-free quantitation enables in-depth monitoring of phosphorylation dynamics with high reproducibility and temporal resolution.

de Graaf Erik L EL Giansanti Piero P Altelaar A F Maarten AF Heck Albert J R AJ

Molecular & cellular proteomics : MCP 20140521 9

Quantitative phosphoproteomics workflows traditionally involve additional sample labeling and fractionation steps for accurate and in-depth analysis. Here we report a high-throughput, straightforward, and comprehensive label-free phosphoproteomics approach using the highly selective, reproducible, and sensitive Ti(4+)-IMAC phosphopeptide enrichment method. We demonstrate the applicability of this approach by monitoring the phosphoproteome dynamics of Jurkat T cells stimulated by prostaglandin E2 ...[more]

PMID: 24850871

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Project description:Prostaglandin E2 (PGE2) is involved in several inflammatory conditions including periodontitis. The aim of this study was to investigate the global gene expression profile of tumor necrosis factor alpha (TNFalpha) stimulated human gingival fibroblasts, focusing on signal pathways related to PGE2 production and the new PGE2-synthesizing enzymes, prostaglandin E synthases (PGES). The expression of microsomal prostaglandin E synthase-1 (mPGES-1) as well as the upstream cyclooxygenase-2 (COX-2) was up-regulated by TNFalpha, accompanied by increased PGE2 production. In contrast, the expression of microsomal prostaglandin E synthase-2 (mPGES-2) and cytosolic prostaglandin E synthase (cPGES) was unaffected by TNFalpha. Using microarray analysis in a time-course factorial design including time points 1, 3 and 6 h, we identified differentially expressed genes in response to TNFalpha treatment. Enrichment analysis of microarray data identified two positively regulated signal transduction pathways: c-Jun N-terminal kinase (JNK) and Nuclear Factor-kappaB (NF-kappaB). We used specific inhibitors and phosphorylation analysis to confirm their role in PGE2 regulation. Both JNK and NF-kappaB inhibitors reduced the TNFalpha-stimulated up-regulation of mPGES-1 and COX-2 as well as subsequent PGE2 production. The novel finding that TNFalpha-stimulated mPGES-1 is regulated by JNK suggests this kinase as a potential future target for treatment strategies in inflammatory disorders, including periodontitis. Keywords: Time course, gene expression, factorial design. Three human gingival fibroblast cell lines were established from gingival biopsies obtained from 3 healthy patients, 3 to 12 years of age, with no clinical signs of periodontal disease. Cells were incubated with or without TNF-alpha (20 ng/ml) for 1, 3 or 6h. After incubation for 1, 3 or 6 h in the two conditions, the cells were immediately frozen in liquid nitrogen and then stored at -70°C for subsequent isolation of total RNA. The experimental design of the microarray study was set up as a time-course factorial design, to best observe the TNF-alpha induced gene expression changes over time. C++ program (G.F. Glonek, P.J. Solomon, Factorial and time course designs for cDNA microarray experiments, Biostatistics 5 (2004) 89-111) was used to determine the exact layout of the design in order to estimate the interaction effect between treatment and time, i.e. genes that are differentially expressed over time, with optimal statistical efficiency. Cyanine 5 and cyanine 3 were used for labeling. For each cell line 12 hybridizations were performed in a time-course factorial design. In total, 36 hybridizations were performed.

Dataset Information

Ti4+-IMAC label-free quantification

Publications

Single-step enrichment by Ti4+-IMAC and label-free quantitation enables in-depth monitoring of phosphorylation dynamics with high reproducibility and temporal resolution.

Similar Datasets

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