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

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.

• Authors: Nathaniel A Jeske, Amol M Patwardhan, Nikita B Ruparel, Armen N Akopian, Mark S Shapiro, Michael A Henry
• Journal: Pain (Pain) Vol. 146 Issue 3 Pg. 301-307 (Dec 2009) ISSN: 1872-6623 [Electronic] United States
• PMID: 19767149 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

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

Topics

• 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, genetics)
• Rats
• Rats, Sprague-Dawley
• TRPV Cation Channels (metabolism, physiology)
• Transfection