Agonist-dependent recruitment of phosphoinositide 3-kinase to the membrane by beta-adrenergic receptor kinase 1. A role in receptor sequestration

J Biol Chem. 2001 Jun 1;276(22):18953-9. doi: 10.1074/jbc.M102376200. Epub 2001 Mar 19.

Abstract

Agonist-dependent desensitization of the beta-adrenergic receptor requires translocation and activation of the beta-adrenergic receptor kinase1 by liberated Gbetagamma subunits. Subsequent internalization of agonist-occupied receptors occurs as a result of the binding of beta-arrestin to the phosphorylated receptor followed by interaction with the AP2 adaptor and clathrin proteins. Receptor internalization is known to require D-3 phosphoinositides that are generated by the action of phosphoinositide 3-kinase. Phosphoinositide 3-kinases form a family of lipid kinases that couple signals via receptor tyrosine kinases and G-protein-coupled receptors. The molecular mechanism by which phosphoinositide 3-kinase acts to promote beta-adrenergic receptor internalization is not well understood. In the present investigation we demonstrate a novel finding that beta-adrenergic receptor kinase 1 and phosphoinositide 3-kinase form a cytosolic complex, which leads to beta-adrenergic receptor kinase 1-mediated translocation of phosphoinositide 3-kinase to the membrane in an agonist-dependent manner. Furthermore, agonist-induced translocation of phosphoinositide 3-kinase results in rapid interaction with the receptor, which is of functional importance, since inhibition of phosphoinositide 3-kinase activity attenuates beta-adrenergic receptor sequestration. Therefore, agonist-dependent recruitment of phosphoinositide 3-kinase to the membrane is an important step in the process of receptor sequestration and links phosphoinositide 3-kinase to G-protein-coupled receptor activation and sequestration.

Publication types

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

MeSH terms

  • 3T3 Cells
  • Adaptor Protein Complex 2
  • Adaptor Protein Complex alpha Subunits
  • Adaptor Proteins, Vesicular Transport
  • Animals
  • Cell Line
  • Cell Membrane / metabolism*
  • Clathrin / metabolism
  • Cyclic AMP-Dependent Protein Kinases / metabolism*
  • Cytosol / metabolism
  • DNA, Complementary / metabolism
  • Dose-Response Relationship, Drug
  • Endocytosis
  • Female
  • Humans
  • Immunoblotting
  • Male
  • Membrane Proteins / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Microscopy, Confocal
  • Myocardium / metabolism
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Phosphorylation
  • Plasmids / metabolism
  • Protein Binding
  • Time Factors
  • beta-Adrenergic Receptor Kinases

Substances

  • Adaptor Protein Complex 2
  • Adaptor Protein Complex alpha Subunits
  • Adaptor Proteins, Vesicular Transport
  • Clathrin
  • DNA, Complementary
  • Membrane Proteins
  • Phosphatidylinositol 3-Kinases
  • Cyclic AMP-Dependent Protein Kinases
  • beta-Adrenergic Receptor Kinases