Expression and function of voltage gated proton channels (Hv1) in MDA-MB-231 cells
Fig 1
Proton current recorded in whole cell patch clamp configuration in an MDA-MD-231 breast cancer cell.
(A) Three families of currents at different pHo all with a pHi of 5.5 (labeled pHo/pHi). Voltage steps are every 10 mV, up to the numbers listed at the top of each family (in mV). The membrane was held at -40 mV (pH 6/5.5 and 5.5/5.5) or -60 mV (pH 7.5/5.5), and pulses were applied with an interval of 20s. The scale bar units are 100 pA and 2 s. (B) The reversal potential (Vrev) of a representative cell measured at each pHo compared to the Nernst potential for protons, which assumes perfect selectivity for H+. (C) Proton conductance (gH) voltage curves derived from the data in A using Vrev measured in each solution. (D) Three families of currents in a cell at pH 6/5.5 with different concentrations of Zn2+ as labelled. Voltage steps are 10 mV apart up to 60 mV. The scale bar units are 50 pA and 2 s.