Phosphoproteomics Data Processing.

MS data were processed using MaxQuant (version 1.5.3.30, http://www.maxquant.org/) using Andromeda as search engine against the Uniprot human protein database (69712 sequences, downloaded from http://www.uniprot.org/) with precursor mass tolerance of 4.5 ppm and fragment mass deviation of 0.5 Da. Variable modifications consisted of methionine oxidation, acetylation of protein N-term and phosphorylation (STY). Fixed modification contained cysteine carbamidomethylation. Trypsin was set as specific proteolytic enzyme. Peptides with a minimum of six amino acids and a maximum of two missed cleavages were allowed for the analysis. For peptide and protein identification, the false discovery rate (FDR) cutoffs were both set to 0.01. Triplets were selected as the quantification mode with the dimethyl Lys 0 and N-term 0 as light labels, dimethyl Lys 4 and N-term 4 as median labels and dimethyl Lys 8 and N-term 8 as heavy labels. All other parameters are the default setting in MaxQuant.