To address whether the interaction of S1P1R with DHHC5 is tight enough for them to behave together during agonist-induced receptor internalisation or is controlled separately, the behaviour of both proteins was analysed after stimulation of cells by a physiological agonist S1P or a pharmacological one, phosphorylated-form of FTY720 (FTY720-P), which is clinically used as an immunosuppressant for multiple sclerosis and that acts through S1PRs23. Here, ZDHHC5 is linked to multiple sclerosis.