Updated project metadata. For protein identification, the following parameters were used. Peptide mass tolerance = 20 ppm, Missed cleavage = 2, MS/MS tolerance = 0.1 Da, Enzyme = Trypsin, Fixed modification: Carbamidomethyl (C), iTRAQ8plex(K), iTRAQ8plex(N-term), Variable modification：Oxidation(M)，Decoy database pattern=Reverse. The MASCOT search results for each SCX elution were further processed using the ProteomicsTools (version 3.1.6) which includes the programs BuildSummary, Isobaric Labeling Multiple File Distiller and Identified Protein iTRAQ Statistic Builder (Information can be accessed from Research Center for Proteome Analysis (http://www.proteomics.ac.cn/).