Figure 2.

Proposed schema for APC signaling in the endothelial cell. APC binds to EPCR, which then interacts with the S1P₁ receptor leading to its phosphorylation by PI3-kinase. S1P₁ signaling through Rac1 leads to cortical cytoskeletal rearrangement and endothelial barrier protection. APC, activated protein C; EPCR, epithelial protein C receptor; PI3-kinase, phosphatidyl-inositol-3 kinase; S1P, sphingosine 1-phosphate. Reprinted with permission from the American Society for Biochemistry and Molecular Biology [28].