The CALHM1 channel transports ATP across the plasma membrane in response to depolarization of the membrane (Taruno et al. 2013). Heteromeric complexes containing both CALHM1 and CALHM3 have voltage-gating that is faster than homomeric CALHM1 complexes and resembles the voltage gating observed in taste cells in vivo (Ma et al. 2018). In mice, knockout of Calhm1 strongly affected voltage-gated currents associated with ATP release and Calhm1 and Calhm3 are sorted to the basolateral membrane of taste cells.