Sphingosine 1-phosphate: synthesis and release.
Sphingosine 1-phosphate (Sph-1-P) is a bioactive sphingolipid, acting both as an intracellular second messenger and extracellular mediator, in mammalian cells. In cell types where Sph-1-P acts as an intracellular messenger, stimulation-dependent synthesis of Sph-1-P, possibly resulting from sphingosine (Sph) kinase activation, is essential. Since this important kinase has recently been cloned, precise regulation of intracellular Sph-1-P synthesis will be clarified in the near future. As an intercellular mediator, elucidation of sources for extracellular Sph-1-P is important, in addition to identification of the cell surface receptors for this phospholipid. Blood platelets are very unique in that they store Sph-1-P abundantly (possibly due to the existence of highly active Sph kinase and a lack of Sph-1-P lyase) and release this bioactive lipid extracellularly upon stimulation. It is likely that platelets are an important source for extracellular Sph-1-P, especially for plasma and serum Sph-1-P. Platelet-derived Sph-1-P seems to play an important role in vascular biology.
Yatomi
Y
Y
Department of Laboratory Medicine, Yamanashi Medical University, Japan. yatomiy@res.yamanashi-med.ac.jp
Ozaki
Y
Y
Ohmori
T
T
Igarashi
Y
Y
D000818:Animals; D001792:Blood Platelets / Q000378:metabolism; D004730:Endothelium, Vascular / Q000502:physiology; D008246:Lysophospholipids; D051379:Mice; D009131:Muscle, Smooth, Vascular / Q000502:physiology; D015290:Second Messenger Systems; D013110:Sphingosine / Q000031:analogs & derivatives / Q000378:metabolism*
D008246:Lysophospholipids; C060506:sphingosine 1-phosphate; D013110:Sphingosine