A GTP analogue induces calcium release but not secretion in rat mast cells.
Two G protein-mediated events, calcium release and secretion, were measured in single rat peritoneal mast cells using the patch-clamp technique. Various phosphorothioate analogues of GTP were introduced into the cells. While GTP gamma S and Rp-GTP alpha S activated both processes, Rp-GTP beta S was found to induce repetitive calcium release in the absence of exocytosis. This response was modulated by IP3, heparin, compound 48/80, and ATP. Our results suggest that Rp-GTP beta S simulates Gp, which links receptors to calcium release.
von zur Mühlen
F
F
Max Planck Institute for Biophysical Chemistry, Göttingen, FRG.
Penner
R
R
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000502:physiology; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology*; D066298:In Vitro Techniques; D008407:Mast Cells / Q000378:metabolism*; D010716:Phosphatidylinositols / Q000378:metabolism; D051381:Rats
D010716:Phosphatidylinositols; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate; D019204:GTP-Binding Proteins; D002118:Calcium