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FEBS Lett. 2003 Nov 20;554(3):443-9.

Photolysis of intracellular caged sphingosine-1-phosphate causes Ca2+ mobilization independently of G-protein-coupled receptors.

Author information

1
Institut f├╝r Pharmakologie, Universit├Ątsklinikum Essen, Hufelandstrasse 55, D-45122 Essen, Germany. meyer-heringdorf@uni-essen.de

Abstract

Sphingosine-1-phosphate (S1P), the product of sphingosine kinase, activates several widely expressed G-protein-coupled receptors (GPCR). S1P might also play a role as second messenger, but this hypothesis has been challenged by recent findings. Here we demonstrate that intracellular S1P can mobilize Ca(2+) in intact cells independently of S1P-GPCR. Within seconds, S1P generated by the photolysis of caged S1P raised the intracellular free Ca(2+) concentration in HEK-293, SKNMC and HepG2 cells, in which the response to extracellularly applied S1P was either blocked or absent. Ca(2+) transients induced by photolysis of caged S1P were caused by Ca(2+) mobilization from thapsigargin-sensitive stores. These results provide direct evidence for a true intracellular action of S1P.

PMID:
14623109
DOI:
10.1016/s0014-5793(03)01219-5
[Indexed for MEDLINE]
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