Fig. 4. Q2S inhibits Q2L or Q3 currents but has little effect on Q2L/Q3 heteromultimer expression. Ratios indicate molar equivalents. Currents were recorded as described in Figure 3.A, Q2L (left); Q2L/Q2S, 1:1 (middle); Q2L/Q2S, 1:5 (right).B, Q3 (left); Q3/Q2S, 1:1 (middle); Q3/Q2S, 1:5 (right).C, Q2L/Q3, 1:1 (left); Q2L/Q3/Q2S, 1:1:1 (middle); Q2L/Q3/Q2S, 1:1:5 (right). Calibration: 1 nA (A, B), 2 nA (C); 400 msec (A–C).D, Current density histogram of KCNQ subunit-transfected cells. Current density measurements are expressed in picoamperes per pico-Faradays and were made from whole-cell current recordings taken during a 1 sec depolarizing step from −70 to 40 mV (holding potential, −70 mV). 2L, Q2L; 2S, Q2S.