A-kinase anchoring protein 150 controls protein kinase C-mediated phosphorylation and sensitization of TRPV1

Pain. 2009 Dec;146(3):301-307. doi: 10.1016/j.pain.2009.08.002. Epub 2009 Sep 19.

Abstract

Post-translational modifications on various receptor proteins have significant effects on receptor activation. For the Transient Receptor Potential family V type 1 (TRPV1) receptor, phosphorylation of certain serine/threonine amino acid residues sensitizes the receptor to activation by capsaicin and heat. Although Protein Kinase C (PKC) phosphorylates TRPV1 on certain serine/threonine residues, it is not completely understood how PKC functionally associates with TRPV1. Recent studies have reported that the A-kinase Anchoring Protein 150 (AKAP150) mediates PKA phosphorylation of TRPV1 in several nociceptive models. Here, we demonstrate that AKAP150 also mediates PKC-directed phosphorylation and sensitization of TRPV1. In cultured rat trigeminal ganglia, immunocytochemical analyses demonstrate co-localization of AKAP150 and PKC isoforms alpha, delta, epsilon, and gamma in TRPV1-positive neurons. Additional biochemical evidence supports immunocytochemical results, indicating that AKAP150 preferentially associates with certain PKC isoforms in rat trigeminal ganglia neurons. Employing siRNA-mediated knock-down of AKAP150 expression, we demonstrate that PKC-mediated phosphorylation of TRPV1 and sensitization to a capsaicin response is dependent upon functional expression of the AKAP150 scaffolding protein. Furthermore, PKC-induced sensitization to a thermal stimulus is abrogated in AKAP150 knock-out animals relative to wild-type. Collectively, the results from these studies indicate that the AKAP150 scaffolding protein functionally modulates PKC-mediated phosphorylation and sensitization of the TRPV1 receptor in rat sensory neurons, suggesting the scaffolding protein to be an integral regulator of peripheral inflammatory hyperalgesia.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • A Kinase Anchor Proteins / physiology*
  • Animals
  • Autoradiography
  • Blotting, Western
  • Calcium Signaling / physiology
  • Electrophysiology
  • Immunohistochemistry
  • Membrane Potentials / physiology
  • Pain Measurement
  • Patch-Clamp Techniques
  • Phosphorylation
  • Protein Kinase C / physiology*
  • RNA, Small Interfering / biosynthesis
  • RNA, Small Interfering / genetics
  • Rats
  • Rats, Sprague-Dawley
  • TRPV Cation Channels / metabolism
  • TRPV Cation Channels / physiology*
  • Transfection

Substances

  • A Kinase Anchor Proteins
  • Akap5 protein, rat
  • RNA, Small Interfering
  • TRPV Cation Channels
  • Trpv1 protein, rat
  • Protein Kinase C