Figure 4. Motif analysis of the phosphosites. (A) Significantly enriched phosphorylation motifs extracted from the overrepresented phosphopeptide dataset by Motif-X. (1) -(19) Motifs from phosphoserine; (20) -(22) Motifs from phosphothreonine. Among these motifs, 6 are identified as 5 known phosphorylation motifs and 17 are newly identified (enclosed into green boxes). The detailed information and putative associated kinases are shown in