Intracellular sphingosine 1-phosphate production: a novel pathway for Ca2+release

Sphingolipids such as sphingosine 1-phosphate (SPP) and sphingosylphosphory lcholine have long been recognised to possess Ca2+ mobilizing activity, yet to dare little is known about their mechanism of action, or indeed their s ignificance as Ca2+ mobilizing intracellular messengers. The recent discove ry of extracellular receptors for the sphingolipids has further complicated the interpretation of many experiments in this field. This paper reviews t he current literature in which molecular and pharmacological approaches hal e begun to uncover the signalling components associated with intracellular SPP production and Ca2+ mobilization. The functional significance of this n ovel Ca2+ release pathway is also discussed.