Thrombin induces phosphoproteomic changes with distinct temporal profiles. (A) Heat map and hierarchical clustering (with k-means) based on the SILAC ratio (log₂) of 2224 thrombin-regulated phosphosites. The 6 clusters discriminate between early- (clusters 1, 2, and 5) and late- (clusters 3, 4, and 6) induced phosphorylation changes, and between upregulated (clusters 1-4) and downregulated (clusters 5 and 6) phosphosites. Heat map colors are based on the SILAC ratio (log₂) reported in supplemental Table 2. (B) Heat map of the gene ontology category enrichment analysis of the 6 clusters in (A). Colors are based on the calculated enrichment factor. Black, not significant. (C) Heat map of the linear amino acid kinase motifs enriched in the 6 clusters in (A) according to Motif-X. Colors are based on the score calculated by Motif-X. Black, not significant. (D) List of the kinases with predicted activity (based on the motifs reported in supplemental Table 2). The dots in the first 4 columns (clusters 1-4 in [A]) refer to kinases with predicted increased activity because they correspond to clusters 1 to 4, which contain phosphosites upregulated upon thrombin stimulation; the dots in the last 2 columns (clusters 5 and 6 in [A]) refer to kinases with predicted decreased activity because they correspond to clusters 5 and 6, which contain phosphosites downregulated upon thrombin stimulation. The colors of the dots are the same as the colors of the clusters in (A). No dot, not significant.