Fig. 4.

Increased actin polymerisation in the presence of PLY. (a) Increased actin stabilisation (increased F-actin in the protein pellet versus G-actin in the solution after sedimentation of F-actin by ultracentrifugation at 150,000g for 90 min) in the presence of 600 nM PLY for 1 h at 24 °C. The amount of actin was measured by anti-actin Western blot analysis. ^⁎p > 0.05, n = 5 experiments. (b) Increased actin polymerisation caused by PLY, but not by IgG (control protein), in a biochemical system, as determined by FRAP analysis of actin-rhodamine 60 min after exposure to the APB (which provides Mg^2 + and ATP). After bleaching of the actin-rhodamine in solution (for 5 s at maximum 561 nm laser power), the change in fluorescence due to diffusion was followed in the bleached area. The longer half-time of fluorescence recovery indicates larger and more slowly diffusing fragments. The larger immobile fraction indicates a larger, completely immobile and presumably highly polymerised fraction. n = 4 experiments. All the values represent the mean ± SEM.