KDM1 is pH sensitive.
(A) Normalized currents of KDM1 expressing oocytes at indicated potentials in 100 mM KCl. ISS were normalized to −150 mV and pH 4 to elucidate the altered pH sensitivity between the KDM1 WT and the H147S mutant (c.f. S8D Fig). Stepwise acidification from pH 7 to 4 increased the potassium currents through KDM1 (n = 20; mean ± SD). (B) The relative open probabilities of KDM1 expressing oocytes at the indicated H+ concentrations were plotted against the applied test voltage. Note the prominent positive shift of the half-maximal activation potential (V1/2) with increasing acidification. The data points were fitted with a Boltzmann function (solid lines; n = 21; mean ± SD). The full raw data are provided in S3 Data. SD, standard deviation.