nbd f

FTY720, an immune modulator, down-regulates sphingosine-1-phosphate (S1P) receptors, enhances the activity of sphingosine transporter Abcb1 and leukotriene C4 transporter Abcc1, and inhibits cytosolic phospholipase A2 activity. Its efficacy relies on in vivo phosphorylation by sphingosine kinases, resulting in FTY720-phosphate which also down-regulates S1P receptors. NBD-FTY720, a fluorescently-labeled analog of FTY720, retains the hydroxy methyl side chain targeted for phosphorylation, suggesting potential phosphorylation in vivo.