Sphingosine-1-phosphate (S1P) modulates skin, vascular endothelial, and immune cells via five distinct G protein-coupled receptors. The S1P type 1 receptor, S1P1, also known as EDG-1, mediates endothelial, lymphoid, and neuronal cell responses to S1P, as well as the synthetic agonist FTY720. W123 is an analog of FTY720 that is a competitive antagonist of S1P1, as measured by GTPγS activation, mitogen-activated protein kinase recruitment, cell migration, and ligand-induced receptor internalization.1 It has a Ki value of 0.69 μM when assessed by SEW2871-induced activation of S1P1.1 Its specificity for other S1P receptor subtypes remains to be determined.
1
Wei, S.H., Rosen, H., Matheu, M.P., et al. Sphingosine 1-phosphate type 1 receptor agonism inhibits transendothelial migration of medullary T cells to lymphatic sinuses. Nat Immunol6(12)1228-1235(2005).