dBest1-F81C–rescued cells respond differently to MTSET⁺ modification than native S2 cells. Whole cell VRAC currents were established in hyposmotic solutions (I340/E300, Δ40 mosmol kg⁻¹) and were recorded with voltage ramps from −100 to 100 mV. 1 mM MTSET⁺ was applied to the bath solution (E300) after the volume-sensitive current was fully activated. The bath was then replaced with 5 mM DTT to test if the effect of MTSET⁺ was reversible. (A and B) Current–voltage relationships in native (A) and dF81C-rescued (B) S2 cells before and after MTSET⁺ modification. (C and D) Time course of the effect of MTSET⁺ modification on native (C) and F81C-rescued (D) VRAC currents. These time course data were collected from the same cells shown in A and B.