title: GABAA receptor associated protein (GABARAP) modulates TRPV1 expression and channel function and desensitization.
abstract: 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.
authors.affiliation: Centro de Investigación Príncipe Felipe, Valencia, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Laínez
authors.forename: P
authors.initials: P
authors.lastname: Valente
authors.forename: I
authors.initials: I
authors.lastname: Ontoria-Oviedo
authors.forename: J
authors.initials: J
authors.lastname: Estévez-Herrera
authors.forename: M
authors.initials: M
authors.lastname: Camprubí-Robles
authors.forename: A
authors.initials: A
authors.lastname: Ferrer-Montiel
authors.forename: R
authors.initials: R
authors.lastname: Planells-Cases
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D051017:Apoptosis Regulatory Proteins; D002118:Calcium / Q000378:metabolism; D002211:Capsaicin / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D004594:Electrophysiology; D005727:Ganglia, Spinal / Q000378:metabolism*; D015723:Gene Library; D006801:Humans; D007124:Immunoenzyme Techniques; D015640:Ion Channel Gating / Q000187:drug effects / Q000502:physiology*; D007668:Kidney / Q000166:cytology / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D018689:Sensory System Agents / Q000494:pharmacology; D050916:TRPV Cation Channels / Q000378:metabolism*; D014404:Tubulin / Q000378:metabolism; D020798:Two-Hybrid System Techniques
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; C116741:GABARAP protein, human; D008869:Microtubule-Associated Proteins; D018689:Sensory System Agents; D050916:TRPV Cation Channels; C494482:TRPV1 protein, human; D014404:Tubulin; D002211:Capsaicin; D002118:Calcium