Centro de Investigación Príncipe Felipe, Valencia, Spain.
FASEB J. 2010 Jun;24(6):1958-70. doi: 10.1096/fj.09-151472. Epub 2010 Feb 23.
Transient receptor potential vanilloid (TRPV1) transduces noxious chemical and physical stimuli in high-threshold nociceptors. The pivotal role of TRPV1 in the physiopathology of pain transduction has thrust the identification and characterization of interacting partners that modulate its cellular function. Here, we report that TRPV1 associates with gamma-amino butyric acid A-type (GABA(A)) receptor associated protein (GABARAP) in HEK293 cells and in neurons from dorsal root ganglia coexpressing both proteins. At variance with controls, GABARAP augmented TRPV1 expression in cotransfected cells and stimulated surface receptor clustering. Functionally, GABARAP expression attenuated voltage and capsaicin sensitivity of TRPV1 in the presence of extracellular calcium. Furthermore, the presence of the anchor protein GABARAP notably lengthened the kinetics of vanilloid-induced tachyphylaxia. Notably, the presence of GABARAP selectively increased the interaction of tubulin with the C-terminal domain of TRPV1. Disruption of tubulin cytoskeleton with nocodazole reduced capsaicin-evoked currents in cells expressing TRPV1 and GABARAP, without affecting the kinetics of vanilloid-induced desensitization. Taken together, these findings indicate that GABARAP is an important component of the TRPV1 signaling complex that contributes to increase the channel expression, to traffic and cluster it on the plasma membrane, and to modulate its functional activity at the level of channel gating and desensitization.
瞬时受体电位香草酸亚型 1（TRPV1）在高阈值伤害感受器中转换有害的化学和物理刺激。TRPV1 在疼痛转导的病理生理学中的关键作用促使人们鉴定和描述调节其细胞功能的相互作用伙伴。在这里，我们报告 TRPV1 在 HEK293 细胞中和共表达这两种蛋白质的背根神经节神经元中与γ-氨基丁酸 A 型（GABA(A)）受体相关蛋白（GABARAP）相关联。与对照不同，GABARAP 在共转染细胞中增加 TRPV1 的表达并刺激表面受体聚类。功能上，在存在细胞外钙的情况下，GABARAP 表达减弱 TRPV1 的电压和辣椒素敏感性。此外，锚蛋白 GABARAP 的存在显著延长了香草素诱导的脱敏的动力学。值得注意的是，GABARAP 选择性增加了微管蛋白与 TRPV1 的 C 末端结构域的相互作用。用诺考达唑破坏微管骨架会减少表达 TRPV1 和 GABARAP 的细胞中辣椒素诱发的电流，而不影响香草素诱导脱敏的动力学。总之，这些发现表明 GABARAP 是 TRPV1 信号复合物的重要组成部分，有助于增加通道表达、将其转运和聚类到质膜上，并调节通道门控和脱敏水平的功能活性。
