Anchoring of protein kinase A facilitates hormone-mediated insulin secretion

Proc Natl Acad Sci U S A. 1997 Dec 23;94(26):14942-7. doi: 10.1073/pnas.94.26.14942.

Abstract

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.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Calcium / metabolism*
  • Cells, Cultured
  • Cyclic AMP-Dependent Protein Kinases / metabolism*
  • Diabetes Mellitus, Type 2 / metabolism
  • Glucagon / pharmacology*
  • Glucagon-Like Peptide 1
  • Insulin / metabolism*
  • Insulin Secretion
  • Pancreas / metabolism*
  • Peptide Fragments / pharmacology*
  • Protein Precursors / pharmacology*
  • Rats

Substances

  • Insulin
  • Peptide Fragments
  • Protein Precursors
  • Glucagon-Like Peptide 1
  • Glucagon
  • Cyclic AMP-Dependent Protein Kinases
  • Calcium