STIMULATION OF CLONED HUMAN GLUCAGON-LIKE PEPTIDE-1 RECEPTOR EXPRESSED IN HEK-293 CELLS INDUCES CAMP-DEPENDENT ACTIVATION OF CALCIUM-INDUCED CALCIUM-RELEASE
J. Gromada et al., STIMULATION OF CLONED HUMAN GLUCAGON-LIKE PEPTIDE-1 RECEPTOR EXPRESSED IN HEK-293 CELLS INDUCES CAMP-DEPENDENT ACTIVATION OF CALCIUM-INDUCED CALCIUM-RELEASE, FEBS letters, 373(2), 1995, pp. 182-186
The actions of glucagon-like peptide-1(7-36)amide (GLP-1(7-36)amide) o
n cellular signalling were studied in human embryonal kidney 293 (HEK
293) cells stably transfected with the cloned human GLP-1 receptor. Th
e cloned GLP-1 receptor showed a single high-affinity binding site (K-
d = 0.76 nM). Binding of GLP-1(7-36)amide stimulated cAMP production i
n a dose-dependent manner (EC(50) = 0.015 nM) and caused an increase i
n the intracellular free Ca2+ concentration ([Ca2+](i)). The latter ef
fect reflected Ca2+-induced Ca2+ release and was suppressed by ryanodi
ne. We propose that the ability of GLP-1(7-36)amide to increase [Ca2+]
(i) results from sensitization of the ryanodine receptors by a protein
kinase A dependent mechanism.