Sphingosine-1-Phosphate Transporters as Targets for Cancer Therapy

Figure 2

Downstream signaling pathways of sphingosine-1-phosphate (S1P) receptors. S1P is a ligand for the five different specific G protein coupled receptors: S1PR1/EDG1; S1PR2/EDG5; S1PR3/EDG3; S1PR4/EDG6; and S1PR5/EDG8. Each S1P receptor is coupled to different G proteins, which regulate activation or inhibition of the indicated downstream signaling pathways, such as adenylyl cyclase-cyclic AMP, AC; extracellular signal-regulated kinase, ERK; phospholipase C, PLC; phosphatidylinositol 3-kinase, PI3K; the small GTPases of the Rho family; and Jun amino terminal kinase, JNK. Only a few examples of these pathways are illustrated.