Effect of amphiphysin truncation mutant on fusion events visualized by IRM. (A) Time course of the IRM signal averaged from synchronous fusion events in control conditions (black) and in cells dialyzed with a pipette solution containing 20 μM of amphiphysinΔSH3 (green). The arrows indicate the time to half maximum (D1/2). Dashed line indicates the baseline level of reflected light. Error bars indicate SEM. (B) Mean values of D1/2 for fusion events observed asynchronously, after uncaging calcium to levels of ∼1 μM, synchronously under control conditions, and synchronously in the presence of 20 μM of amphiphysinΔSH3. Error bars indicate SEM. (C) Distribution of time to D1/2 values for synchronous events under control conditions (gray) and after the introduction of amphiphysinΔSH3 (green). (D) Distributions for asynchronous events (gray) and during dialysis with 20 μM of amphiphysin N-BAR domain (green). (E) Mean change in capacitance in response to a 0.5-s stimulation in control conditions (black; 13 cells) and in cells dialyzed with 20 μM of amphiphysinΔSH3 (green; 9 cells). Dashed line indicates the baseline level of capacitance. Error bars indicate SEM. (F) The presence of 20 μM of amphiphysinΔSH3 did not modify calcium currents. Error bars indicate SEM.
