Figure 6.

Camphor activates NvHsTRPA but not N-terminal-deleted AmHsTRPA mutant and SiHsTRPA added with N terminus of AmHsTRPA. Responses of N-terminal-deleted AmHsTRPA mutant (AmHsTRPA ΔN), SiHsTRPA added with N terminus of AmHsTRPA (AmHsTRPA-N + SiHsTRPA), and NvHsTRPA to camphor and diallyl disulfide were tested by calcium imaging. Red bars show the period when each compound was added, and then washed off. C10 was applied to the mutants after testing camphor as shown by blue bars. Arrows show the time points when ionomycin was added. The mean value of fold change of Fura-2 ratio with error bar (± SEM) is shown for the compound stimulated DsRed-positive (blue) and -negative (yellow) cells. The total numbers of AmHsTRPA ΔN-, AmHsTRPA-N + SiHsTRPA-, and NvHsTRPA-transfected cells analyzed were 100–114, 104–109, and 46–90, respectively. **, Significant difference by one-tailed Welch’s t test (P < 0.001). Amino acid sequence alignment of wasp, bee, and ant HsTRPA channels is shown in extended data Fig. 6-1. Molecular phylogenetic tree of wasp, bee, and ant HsTRPA channels is indicated in extended data Fig. 6-2.