Mapping the Binding Site of TRPV1 on AKAP79: Implications for Inflammatory Hyperalgesia

TY - JOUR

T1 - Mapping the Binding Site of TRPV1 on AKAP79

T2 - Implications for Inflammatory Hyperalgesia

AU - Btesh, Joan

AU - Fischer, Michael J. M.

AU - Stott, Katherine

AU - McNaughton, Peter A.

PY - 2013/5/22

Y1 - 2013/5/22

N2 - Inflammation causes hyperalgesia, an enhanced sensitivity to noxious stimuli. Transient receptor potential vanilloid 1 (TRPV1), a thermo-TRP ion channel activated by painful levels of heat, is an important contributor because hyperalgesia is reduced when TRPV1 is either genetically deleted or pharmacologically blocked. Inflammatory mediators such as prostaglandin-E2 or bradykinin cause hyperalgesia by activating cellular kinases that phosphorylate TRPV1, a process that has recently been shown to rely on a scaffolding protein, AKAP79, to target the kinases to TRPV1. Here we use Forster resonance energy transfer, immunoprecipitation, and TRPV1 membrane trafficking experiments to identify a key region on AKAP79, between amino acids 326-336, which is responsible for its interaction with TRPV1. A peptide identical to this domain inhibited sensitization of TRPV1 in vitro, and when covalently linked to a TAT peptide to promote uptake across the cell membrane the peptide inhibited in vivo inflammatory hyperalgesia in mice. Critically, it did so without affecting pain thresholds in the absence of inflammation. These results suggest that antagonizing the TRPV1-AKAP79 interaction will be a useful strategy for inhibiting inflammatory hyperalgesia.

AB - Inflammation causes hyperalgesia, an enhanced sensitivity to noxious stimuli. Transient receptor potential vanilloid 1 (TRPV1), a thermo-TRP ion channel activated by painful levels of heat, is an important contributor because hyperalgesia is reduced when TRPV1 is either genetically deleted or pharmacologically blocked. Inflammatory mediators such as prostaglandin-E2 or bradykinin cause hyperalgesia by activating cellular kinases that phosphorylate TRPV1, a process that has recently been shown to rely on a scaffolding protein, AKAP79, to target the kinases to TRPV1. Here we use Forster resonance energy transfer, immunoprecipitation, and TRPV1 membrane trafficking experiments to identify a key region on AKAP79, between amino acids 326-336, which is responsible for its interaction with TRPV1. A peptide identical to this domain inhibited sensitization of TRPV1 in vitro, and when covalently linked to a TAT peptide to promote uptake across the cell membrane the peptide inhibited in vivo inflammatory hyperalgesia in mice. Critically, it did so without affecting pain thresholds in the absence of inflammation. These results suggest that antagonizing the TRPV1-AKAP79 interaction will be a useful strategy for inhibiting inflammatory hyperalgesia.

KW - PROTEIN-KINASE-C

KW - VANILLOID RECEPTOR TRPV1

KW - ACTIVATED ION-CHANNEL

KW - CAPSAICIN RECEPTOR

KW - THERMAL HYPERALGESIA

KW - PROSTAGLANDIN E-2

KW - NEUROPATHIC PAIN

KW - SIGNALING COMPLEX

KW - FRET MICROSCOPY

KW - SENSORY NEURONS

U2 - 10.1523/JNEUROSCI.4991-12.2013

DO - 10.1523/JNEUROSCI.4991-12.2013

M3 - Article

SN - 0270-6474

VL - 33

SP - 9184

EP - 9193

JO - Journal of Neuroscience

JF - Journal of Neuroscience

IS - 21

ER -