Subsequent studies have revealed putative PIP2-interacting domains in the polybasic proximal C-terminal region of TRPV1. In addition, polyunsaturated fatty acids, their metabolites and lysophosphatidic acid are also known to modulate TRPV1channel function. Interestingly, intracellular levels of the anionic long chain acyl CoA esters are increased in many pathophysiological conditions including those mentioned above, resulting in alterations of metabolic enzyme activity, gene transcription and the immune mediated inflammatory response. Similar to PIP2, LC-CoAs are comprised of a hydrophobic tail with a negatively charged head group. Our group and others have shown that LC-CoAs have a direct and potent stimulatory effect on the ATP-sensitive potassium channel and that PIP2 and LC-CoAs possess a similar molecular mechanism of action via interaction with intracellular positively charged basic regions of the KATP channel. Additional work in our laboratory also shows that LC-acyl CoAs and PIP2 modulate the sodium-calcium exchanger via interaction with common basic residues. Therefore, in this current study we investigated whether LCCoAs, like PIP2, regulate TRPV1 activity by characterizing the effects of physiological intracellular concentrations of common dietary LC-CoAs on recombinant TRPV1 channel activity. We also determined the effects of intracellular LC-CoA elevation on TRPV1 channel-mediated intracellular Ca2+ accumulation in intact cell models. Finally, we investigated the role of known PIP2 interacting amino acid residues in the TRPV1 channel to elucidate the molecular interactions responsible for LC-CoA modulation of TRPV1 channel function. Our results demonstrate that sub-micromolar physiological levels LC-CoAs are potent positive modulators of TRPV1 channel activity and act via a similar, but not identical, molecular mechanism to PIP2. Though the precise molecular mechanisms may differ, it is well known that PIP2 regulates the function of many trans-membrane ion transport proteins. Early studies stated that PIP2 had a tonic inhibitory effect on TRPV1 channel function proposing that this inhibition was relieved by nerve growth factor via activation of its tyrosine kinase receptor and effector PLC, resulting in PIP2 cleavage. Further investigation found that NGF actually led to an increase in the amount of TRPV1 channels present at the membrane, questioning the theory of PIP2 TRPV1 inhibition. Though some controversy still exists it is now generally accepted that depletion of PIP2 from the plasma membrane leads to inactivation of TRPV1 channels, suggesting that PIP2 is both a positive modulator of TRPV1 and a requirement for channel function. Our current data show that TRPV1 is positively modulated by LC-CoAs. Indeed, previous work in our laboratory has shown that LC-CoAs modulate KATP channels and NCX1 in a similar manner to PIP2.