Abstract
The heat-responses of the homotetrameric thermosensitive transient receptor potential vanilloid (TRPV)1-4 channels are use-dependent. The initial short heat stimulus typically alters the temperature threshold and sensitivity for the subsequent one. The precise underlying structural motifs have not been identified except for TRPV1 and TRPV3. Since the release of lipid from the active vanilloid site is necessary for the initial heat activation of TRPV1 or TRPV3, the 3D cryo-EM structures of apo rat TRPV2 with or without any lipid in different gating states were analyzed using a highly sensitive thermoring model. The results indicated that two lipids in the voltage sensor-like domain and at the vanilloid site needed to be released to achieve theoretically and experimentally matched start and end thresholds and thermosensitivities during the first and second heat sensations. Therefore, this study further elucidated the role of lipids at various sites in the use-dependent heat responses of thermosensitive TRPV1-4 channels.