Figure 1. Time-course of prestin expression and function in transiently transfected HEK 293 cells.

A) Top panel: representative western blot of biotinylated cell surface proteins showing a gradual increase in prestin expression with time after transient transfection with HA-prestin. Bottom panel: average band intensity of prestin relative to EGFR calculated from three independent western blots as a function of time post-transfection. B) Average charge density for three groups of time points (10–16 hrs, 18–30 hrs, and 36–48 hrs). The 36–48 hour group showed a statistically significant increase (p<0.005) in comparison with the 10–16 hour group using the Student’s t-test with Holm adjustment of p-values for multiple comparisons. Sample size, n = 18, 14 and 11 for the 10–16, 18–30 and the 36–48 hour groups respectively. C) Average z values of prestin transfected cells at different time points post-transfection. There were no statistically significant differences in the unitary charge valence (z) with time post-transfection. Sample sizes were the same as in (B). D) Individual data points of V_pkc at time-points post transfection. The V_pkc remains fairly constant between 10 and 48 hours. Sample sizes were the same as in (B). E) Average charge densities of prestin transfected cells at different time-points post-transfection. Error bars represent standard deviation in all panels. Spearman rho correlation coefficient and associated p-value were calculated to estimate correlation significance.