Alternatively, we monitored calcium signals in F-11 neuronal cells expressing TRPM8 with/out scPPX1 (Fig. 2D–F). Similarly to HEK cells expression system, we found that Ca2+-entry was significantly inhibited in F-11 cells when TRPM8 was
co-expressed together with polyphosphatase, which indicates that polyP plays an analogously important role on the TRPM8 activity in these cells as well. These results demonstrate a novel and significant contribution of polyP to TRPM8 channel activity. The question of how polyP contributes to the regulation of TRPM8 channel activity motivated us to look at the biochemical and biophysical properties