Figure 2.

Ca²⁺ selectivity of TRP channels. (A) Ca²⁺ selectivity of TRP channels expressed as $P_{{\mathit{Ca}}^{2+}}/P_{{\mathit{Na}}^{+}}(/{\mathit{Cs}}^{+})$ (depending on availability). Bars indicate maximal and minimal values found in literature; TRPM4 and TRPM5 are impermeable to Ca²⁺ (for TRPM1, values are deduced from Oancea et al. 2009). (B) Fractional Ca²⁺ current of TRP channels as found in literature (for TRPM3 Oberwinkler personal communication, see Drews et al. 2010).