A-kinase anchoring protein 150 (AKAP150) is a scaffolding protein that controls protein kinase A- and C-mediated phosphorylation of the transient receptor potential family V type 1 (TRPV1), dictating receptor response to nociceptive stimuli. The phospholipid phosphatidylinositol-4,5-bisphosphate (PIP2) anchors AKAP150 to the plasma membrane in naive conditions and also affects TRPV1 activity. In the present study, we sought to determine whether the effects of PIP2 on TRPV1 are mediated through AKAP150. In trigeminal neurons and CHO cells, the manipulation of cellular PIP2 led to significant changes in the association of AKAP150 and TRPV1. Following PIP2 degradation, increased TRPV1: AKAP150 coimmunoprecipitation was observed, resulting in increased receptor response to capsaicin treatment. Phospholipase C activation in neurons isolated from AKAP150 animals indicated that PIP2-mediated inhibition of TRPV1 in the whole-cell environment requires expression of the scaffolding protein. Furthermore, the addition of PIP2 to neurons isolated from AKAP150 wild-type mice reduced PKA sensitization of TRPV1 compared with isolated neurons from AKAP150 mice. These findings suggest that PIP2 degradation increases AKAP150 association with TRPV1 in the whole-cell environment, leading to sensitization of the receptor to nociceptive stimuli.
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