Phosphoinositide 3-Kinase Binds to TRPV1 and Mediates NGF-stimulated TRPV1 Trafficking to the Plasma Membrane

摘要: Sensitization of the pain-transducing ion channel TRPV1 underlies thermal hyperalgesia by proalgesic agents such as nerve growth factor (NGF). The currently accepted model is that NGF-mediated increase in function during utilizes activation phospholipase C (PLC) to cleave PIP2, proposed tonically inhibit TRPV1. In this study, we tested PLC and found two lines evidence directly challenge its validity: (1) polylysine, a cationic phosphoinositide sequestering agent, inhibited instead potentiating it, (2) direct application PIP2 inside-out excised patches dramatically potentiated Furthermore, show four types experiments indicating PI3K physically functionally coupled TRPV1: p85β subunit interacted with N-terminal region yeast 2-hybrid experiments, PI3K-p85β coimmunoprecipitated from both HEK293 cells dorsal root ganglia (DRG) neurons, (3) recombinant PI3K-p85 vitro, (4) wortmannin, specific inhibitor PI3K, completely abolished sensitization acutely dissociated DRG neurons. Finally, simultaneous electrophysiological total internal reflection fluorescence (TIRF) microscopy recordings demonstrate NGF increased number channels plasma membrane. We propose new for which physical coupling signal transduction complex facilitates trafficking