Two GTP-binding Proteins Control Calcium-dependent Exocytosis in Chromaffin Cells.
The effect of guanosine triphosphate analogues on catecholamine secretion from permeabilized bovine chromaffin cells was examined. Guanosine 5'-[gamma-thio]triphosphate was demonstrated to produce a dual effect on calcium-evoked secretion, enhancing the release through a mechanism involving protein kinase C and inhibiting secretion by a protein kinase C-independent pathway. We propose that two functionally distinct G-proteins control the stimulus - secretion coupling in chromaffin cells.
Sontag
Jean-Marie
JM
Unité INSERM U-338 Biologie de la Communication Cellulaire, 5, rue Blaise Pascal, 67084 Strasbourg Cédex, France.
Aunis
Dominique
D
Bader
Marie-France
MF