Fig. 3: Membrane-binding stabilization via electrostatic interactions.
(a–c) Diffusion trajectories of single molecules of PTEN-Halo (a), PTENR47A-Halo (b), and PTENN4-Halo (c) labeled with TMR on artificial membranes of 10 mol% PI(4,5)P2. Colors indicate the magnitude of the displacement of the molecule within a unit time interval of Δt = 16.5 ms. Scale bars, 10 μm. d Probability density distributions of the displacement (Δt = 16.5 ms) of single PTEN molecules on the membranes of 10 mol% PI(4,5)P2. e Diffusion coefficients, D1 and D2, for slower and faster mobility states, respectively. Welch’s t test; comparisons were made with “WT” column for the same state. f The number of PTEN molecules adopting the slower mobility state normalized to the total number of molecules. Welch’s t test; comparisons were made with “WT” column. g Dissociation curves of single molecules on the membranes of 10 mol% PI(4,5)P2. h Dissociation rate constants, k1 and k2, for the longer and shorter binding states, respectively. Welch’s t test; comparisons were made with “WT” column for the same state. i The number of PTEN molecules adopting the longer binding state normalized to the total number of molecules. Welch’s t test; comparisons were made with “WT” column. j, k PI(4,5)P2 dependency of the average diffusion coefficient and average dissociation rate constant of PTEN (blue rectangle), PTENR47A (orange triangle), and PTENN4 (magenta circle). Welch’s t test; comparisons were made with “1 mol% PI(4,5)P2” column for the same cell types. Blue, orange, and magenta indicate PTENWT, PTENR47A, and PTENN4, respectively. l Estimation of the number of mobility states using the data obtained from each video (PI(4,5)P2 density = 10 mol%). Light, middle, and dark colors indicate the ratio of the videos in which the AIC values show AIC1 − AIC2 < 0 (1 state model), 0 < AIC1 − AIC2 < 4 (2 state model), and 4 < AIC1 − AIC2 (2 state model). N = 4500 (1 mol%), 5997 (5 mol%), and 4365 (10 mol%) PTENR47A molecules; 7056 (1 mol%), 4499 (5 mol%), and 4500 (10 mol%) PTENN4 molecules. Data are mean ± SD from 3 separate movies in 3 independent experiments (n = 9).
