title: 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.affiliation: Department of Oral and Maxillofacial Surgery, The University of Texas Health Science Center at San Antonio, TX 78229, USA Department of Endodontics, The University of Texas Health Science Center at San Antonio, TX 78229, USA Department of Cellular and Structural Biology, The University of Texas Health Science Center at San Antonio, TX 78229, USA Department of Physiology, The University of Texas Health Science Center at San Antonio, TX 78229, USA.
authors.forename: Nathaniel A
authors.initials: NA
authors.lastname: Jeske
authors.forename: Amol M
authors.initials: AM
authors.lastname: Patwardhan
authors.forename: Nikita B
authors.initials: NB
authors.lastname: Ruparel
authors.forename: Armen N
authors.initials: AN
authors.lastname: Akopian
authors.forename: Mark S
authors.initials: MS
authors.lastname: Shapiro
authors.forename: Michael A
authors.initials: MA
authors.lastname: Henry
mesh_terms: D054758:A Kinase Anchor Proteins / Q000502:physiology*; D000818:Animals; D001345:Autoradiography; D015153:Blotting, Western; D020013:Calcium Signaling / Q000502:physiology; D004594:Electrophysiology; D007150:Immunohistochemistry; D008564:Membrane Potentials / Q000502:physiology; D010147:Pain Measurement; D018408:Patch-Clamp Techniques; D010766:Phosphorylation; D011493:Protein Kinase C / Q000502:physiology*; D034741:RNA, Small Interfering / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D050916:TRPV Cation Channels / Q000378:metabolism / Q000502:physiology*; D014162:Transfection
chemical_list: D054758:A Kinase Anchor Proteins; C415703:Akap5 protein, rat; D034741:RNA, Small Interfering; D050916:TRPV Cation Channels; C493922:Trpv1 protein, rat; D011493:Protein Kinase C