The secretory machinery. (A) Drawing representing the mechanisms involved in Weibel-Palade body release, based on literature data. MS-identified phosphoproteins for which significantly regulated phosphosites were measured are indicated with an orange border. Each P indicates a distinct regulated phosphosite, and the color is the same as that of the cluster it belongs to, according to Figure 2A. (B) Detailed list of the phosphosites depicted in (A). The reported amino acid position refers to the protein within the protein group for which a reference number (referred to as UniProtKB) was found in PhosphoSitePlus database. Bold, functional phosphosite (according to PhosphoSitePlus); ^, a redundant site. (C) Heat map of the SILAC (log₂) ratio of 77 proteins of the BOEC secretome with increased abundance upon thrombin stimulation. The black lines indicate 2 groups of proteins with increased levels measured after 2 to 5 minutes (early) or 10 to 30 minutes (late). Colors are based on the SILAC ratio (log₂) reported in supplemental Table 4. (D) List of the gene names of the proteins represented in the heat map in (C). (E) Enriched gene ontology and Kyoto Encyclopedia of Genes and Genomes categories (see also supplemental Table 5) for the proteins with increased secretion upon thrombin stimulation and reported in (D).