All MS raw data were processed using Proteome Discoverer 1.4 (Thermo Scientific). Data were searched against the human Universal Protein Resource sequence database (UniProt). The search parameters were set as follows: enzyme, trypsin; fixed modification, carbamidomethyl (Cys); variable modification, oxidation (Met), TMT/+ 229D-K, TMT/+ 229D-N Terminal; maximum miss cleavage, 2; 10 ppm precursor tolerance; 0.02 Da fragment ion tolerance; false discovery rate (FDR) at peptide and protein levels, < 0.01; and required peptide length, > 6 amino acids.
