Phosphorylation by $Ca^{+2}$/calmodulin-dependent Kinase II Regulates Binding of Capsaicin to VR1

VR1, a capsaicin receptor, is now known to playa major role in mediating inflammatory thermal nociception. Although the physiological role or biophysical properties of VR1 are known, its activation mechanisms by ligands are poorly understood. Here, we show that VR1 requires phosphorylation by $Ca^{2+}$-calmodulin-dependent kinase II (CaMKII) for its activation by capsaicin. In contrast, dephosphorylation by calcineurin, leads to desensitization of the receptor. Point mutation of VR1 at two putative consensus sites for CaMKII fails to elicit capsaicin-sensitive currents with concomitant reduction in phosphorylation of VR1 in vivo. (omitted)