Anchoring of protein kinase A facilitates hormone-mediated insulin secretion

LB Lester, LK Langeberg… - Proceedings of the …, 1997 - National Acad Sciences
Proceedings of the National Academy of Sciences, 1997National Acad Sciences
Impaired insulin secretion is a characteristic of non-insulin-dependent diabetes mellitus
(NIDDM). One possible therapeutic agent for NIDDM is the insulinotropic hormone glucagon-
like peptide 1 (GLP-1). GLP-1 stimulates insulin secretion through several mechanisms
including activation of protein kinase A (PKA). We now demonstrate that the subcellular
targeting of PKA through association with Ak inase-a nchoring p roteins (AKAPs) facilitates
GLP-1-mediated insulin secretion. Disruption of PKA anchoring by the introduction of …
Impaired insulin secretion is a characteristic of non-insulin-dependent diabetes mellitus (NIDDM). One possible therapeutic agent for NIDDM is the insulinotropic hormone glucagon-like peptide 1 (GLP-1). GLP-1 stimulates insulin secretion through several mechanisms including activation of protein kinase A (PKA). We now demonstrate that the subcellular targeting of PKA through association with A-kinase-anchoring proteins (AKAPs) facilitates GLP-1-mediated insulin secretion. Disruption of PKA anchoring by the introduction of anchoring inhibitor peptides or expression of soluble AKAP fragments blocks GLP-1 action in primary islets and cAMP-responsive insulin secretion in clonal beta cells (RINm5F). Displacement of PKA also prevented cAMP-mediated elevation of intracellular calcium suggesting that localized PKA phosphorylation events augment calcium flux.
National Acad Sciences