ATM and ATR- dependent protein phosphorylation induced within 15 minutes after gamma irradiation in Arabidopsis thaliana

Pilotexp_IMAC_TiO2_eluate_ATM_ATR_dep_phos_15min_postIR: Proteins were isolated from 4 different conditions of Arabidopsis thaliana plants: wild type untreated, wild type irradiated, atm/atr mutant untreated, atm/atr mutant irradiated The proteins were tryptically digested and labelled each with one channel ofthe iTRAQ4plex reagent. The samples were mixed and subjected to phosphopeptide enrichment by IMAC followed by TiO2. The enriched phosphopeptides were separated by SCX and each fraction was analysed by nano-reversed phase HPLC coupled online to a LTQ Orbitrap Velos. Each peptide was fragmented both by CID (MSA) and HCD, using the iontrap-MS analyser for CID and the Orbitrap detector for HCD scans. IMAC_TiO2_eluate_ATM_ATR_dep_phos_15min_postIR: Proteins were isolated from 4 different conditions of Arabidopsis thaliana plants: wild type untreated, wild type irradiated, atm/atr mutant untreated, atm/atr mutant irradiated The proteins were tryptically digested and labelled each with one channel ofthe iTRAQ4plex reagent. The samples were mixed and subjected to phosphopeptide enrichment by IMAC followed by TiO2. The enriched phosphopeptides were separated by SCX and each fraction was analysed by nano-reversed phase HPLC coupled online to a LTQ Orbitrap Velos. Each peptide was fragmented both by CID (MSA) and HCD, using the iontrap-MS analyser for CID and the Orbitrap detector for HCD scans. IMAC_TiO2_FT_ATM_ATR_dep_phos_15min_postIR: Proteins were isolated from 4 different conditions of Arabidopsis thaliana plants: wild type untreated, wild type irradiated, atm/atr mutant untreated, atm/atr mutant irradiated The proteins were tryptically digested and labelled each with one channel ofthe iTRAQ4plex reagent. The samples were mixed and subjected to phosphopeptide enrichment by IMAC followed by TiO2. The unphosphorylated peptides found in the flowthrough of the TiO2 column were separated by SCX and each fraction was analysed by nano-reversed phase HPLC coupled online to a LTQ Orbitrap Velos. Each peptide was fragmented both by CID and HCD, using the iontrap-MS analyser for CID and the Orbitrap detector for HCD scans. The iTRAQ ratio obtained for the unmodified peptides from this flowthrough sample was used to calculate protein ratios for the 4 different conditions.