TY - JOUR
T1 - Protein kinase A anchoring via AKAP150 is essential for TRPV1 modulation by forskolin and prostaglandin E2 in mouse sensory neurons
AU - Schnizler, Katrin
AU - Shutov, Leonid P.
AU - Van Kanegan, Michael J.
AU - Merrill, Michelle A.
AU - Nichols, Blake
AU - McKnight, G. Stanley
AU - Strack, Stefan
AU - Hell, Johannes W
AU - Usachev, Yuriy M.
PY - 2008/5/7
Y1 - 2008/5/7
N2 - Phosphorylation-dependent modulation of the vanilloid receptor TRPV1 is one of the key mechanisms mediating the hyperalgesic effects of inflammatory mediators, such as prostaglandin E2 (PGE2). However, little is known about the molecular organization of the TRPV1 phosphorylation complex and specifically about scaffolding proteins that position the protein kinase A (PKA) holoenzyme proximal to TRPV1 for effective and selective regulation of the receptor. Here, we demonstrate the critical role of the A-kinase anchoring protein AKAP150 in PKA-dependent modulation of TRPV1 function in adult mouse dorsal root ganglion (DRG) neurons. We found that AKAP150 is expressed in ∼80% of TRPV1-positive DRG neurons and is coimmunoprecipitated with the capsaicin receptor. In functional studies, PKA stimulation with forskolin markedly reduced desensitization of TRPV1. This effect was blocked by the PKA selective inhibitors KT5720 [(9S,10R,12R)-2,3,9,10,11,12-hexahydro-10- hydroxy-9-methyl-1-oxo-9,12-epoxy-1H-diindolo[1,2,3-fg:3′,2′, 1′-kl]pyrrolo[3,4-i][1,6]benzodiazocine-10-carboxylicacid hexyl ester] and H89 (N-[2-( p-bromo-cinnamylamino)-ethyl]-5-isoquinoline-sulfon-amide 2HCl), as well as by the AKAP inhibitory peptide Ht31. Similarly, PGE2 decreased TRPV1 desensitization in a manner sensitive to the PKA inhibitor KT5720. Both the forskolin and PGE2 effects were strongly impaired in DRG neurons from knock-in mice that express a mutant AKAP150 lacking the PKA-binding domain (Δ36 mice). Protein kinase C-dependent sensitization of TRPV1 remained intact in Δ36 mice. The PGE2/PKA signaling defect in DRG neurons from Δ36 mice was rescued by overexpressing the full-length human ortholog of AKAP150 in these cells. In behavioral testing, PGE2-induced thermal hyperalgesia was significantly diminished in Δ36 mice. Together, these data suggest that PKA anchoring by AKAP150 is essential for the enhancement of TRPV1 function by activation of the PGE 2/PKA signaling pathway.
AB - Phosphorylation-dependent modulation of the vanilloid receptor TRPV1 is one of the key mechanisms mediating the hyperalgesic effects of inflammatory mediators, such as prostaglandin E2 (PGE2). However, little is known about the molecular organization of the TRPV1 phosphorylation complex and specifically about scaffolding proteins that position the protein kinase A (PKA) holoenzyme proximal to TRPV1 for effective and selective regulation of the receptor. Here, we demonstrate the critical role of the A-kinase anchoring protein AKAP150 in PKA-dependent modulation of TRPV1 function in adult mouse dorsal root ganglion (DRG) neurons. We found that AKAP150 is expressed in ∼80% of TRPV1-positive DRG neurons and is coimmunoprecipitated with the capsaicin receptor. In functional studies, PKA stimulation with forskolin markedly reduced desensitization of TRPV1. This effect was blocked by the PKA selective inhibitors KT5720 [(9S,10R,12R)-2,3,9,10,11,12-hexahydro-10- hydroxy-9-methyl-1-oxo-9,12-epoxy-1H-diindolo[1,2,3-fg:3′,2′, 1′-kl]pyrrolo[3,4-i][1,6]benzodiazocine-10-carboxylicacid hexyl ester] and H89 (N-[2-( p-bromo-cinnamylamino)-ethyl]-5-isoquinoline-sulfon-amide 2HCl), as well as by the AKAP inhibitory peptide Ht31. Similarly, PGE2 decreased TRPV1 desensitization in a manner sensitive to the PKA inhibitor KT5720. Both the forskolin and PGE2 effects were strongly impaired in DRG neurons from knock-in mice that express a mutant AKAP150 lacking the PKA-binding domain (Δ36 mice). Protein kinase C-dependent sensitization of TRPV1 remained intact in Δ36 mice. The PGE2/PKA signaling defect in DRG neurons from Δ36 mice was rescued by overexpressing the full-length human ortholog of AKAP150 in these cells. In behavioral testing, PGE2-induced thermal hyperalgesia was significantly diminished in Δ36 mice. Together, these data suggest that PKA anchoring by AKAP150 is essential for the enhancement of TRPV1 function by activation of the PGE 2/PKA signaling pathway.
KW - AKAP150
KW - DRG neurons
KW - PKA
KW - Prostaglandin E
KW - Thermal hypersensitivity
KW - TRPV1
UR - http://www.scopus.com/inward/record.url?scp=44949131718&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=44949131718&partnerID=8YFLogxK
U2 - 10.1523/JNEUROSCI.0233-08.2008
DO - 10.1523/JNEUROSCI.0233-08.2008
M3 - Article
C2 - 18463244
AN - SCOPUS:44949131718
VL - 28
SP - 4904
EP - 4917
JO - Journal of Neuroscience
JF - Journal of Neuroscience
SN - 0270-6474
IS - 19
ER -