Mapping the binding site of TRPV1 on AKAP79: implications for inflammatory hyperalgesia.
Mapping the binding site of TRPV1 on AKAP79: implications for inflammatory hyperalgesia.
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DOI：
10.1523/jneurosci.4991-12.2013
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发表时间：
2013-05-22
期刊：
影响因子：
--
通讯作者：
McNaughton PA
中科院分区：
文献类型：
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作者：
Btesh J;Fischer MJM;Stott K;McNaughton PA
炎症会引起痛敏，即对有害刺激的敏感性增强。瞬时受体电位香草素1(TRPV1)是一种由痛苦的热激活的热-色氨酸离子通道，是一个重要的因素，因为当TRPV1基因缺失或药物阻断时，痛敏反应会减少。炎症介质，如前列腺素E_2或缓激肽，通过激活使TRPV1磷酸化的细胞激酶而引起痛敏，这一过程最近被证明依赖于支架蛋白AKAP79来靶向TRPV1的激酶。在这里，我们使用Förster共振能量转移、免疫沉淀和TRPV1膜转运实验来确定AKAP79上326-336氨基酸之间的一个关键区域，该区域负责其与TRPV1的相互作用。与该结构域相同的多肽在体外抑制TRPV1的敏化，当共价连接到TAT多肽以促进跨细胞膜的摄取时，该多肽在体内抑制小鼠的炎性痛觉过敏。关键的是，它在没有炎症的情况下做到了这一点，没有影响痛阈值。这些结果表明，拮抗TRPV1-AKAP79的相互作用将是抑制炎性痛觉过敏的有效策略。
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 Förster 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.