FIGURE 9:

Dynamin is associated with MLCK in response to cell swelling and contributes to ring turnover and volume recovery. Lysates were extracted from cells under isotonic conditions (time = 0) and at different times (in min) after hypotonic exposure and then fractionated as described in Materials and Methods; heavy membrane fractions include plasma membrane, and light membrane fractions include small vesicles. Representative immunoblots of Src and MLCK immunoprecipitates of these fractions are shown in (A) and (B), respectively. (C) Effect of the dynamin inhibitor dynasore (80 μM) on cell volume recovery following hypotonic exposure (initiated at the time indicated by the arrow). (D) Effect of dynamin on MLCK ring abundance. GFP-MLCK–expressing cells were fixed after hypotonic exposure in the absence (control) or presence of dynasore (80 μM), and ring structures at the base were counted.