FIGURE 9.

Analysis of the diffusion of KCNQ1 channels (in HEK293 cells, 37 °C) indicates a transient, stop-start, behavior. A, velocity and variance of molecular displacements are plotted against time for 11 molecules concatenated into a single data series. The vertical dotted lines indicate where data for each molecule starts and ends. The horizontal dotted line indicates the variance threshold used to discriminate periods of paused movement. B, histogram showing the distribution of the lifetimes of paused intervals. The solid black line is a least-squares fit to a single exponential, A_t = A_oe^−rt, where r = 4 s⁻¹.