Dynamics and mobility of hFLNc is controlled by phosphorylation and cleavage of its Ig-like domain 24.
A, Immortalized mouse myoblasts (IMMs) were transfected with constructs for EGFP-tagged full-length hFLNc WT, S2623/2624 phosphosite mutants (AA, DD), or hFLNc lacking Ig-like domain 24. IMMs expressing full-length hFLNc WT were treated with PKC inhibitor Gö6976 for 1 h or not before fluorescence recovery after photobleaching (FRAP) analysis. Shown is a representative FRAP experiment with IMMs after 5 days of differentiation before bleaching (prebleach), immediately (postbleach), 5 and 20 s after bleaching, and after full recovery (recovery). Boxes indicate the region bleached. Scale bar: 5 μm. B, Quantification of data from FRAP studies described in (A). Statistical data are depicted in box and whisker plots. Each calculated median halftime is shown as a line surrounded by a box, which represents the interquartile range comprising the median ± 25% of the data. Whiskers extend at most two standard deviations from the median. Data from n ≥ 10 independent experiments are shown. **p ≤ 0.0011, ***p ≤ 0.0003. C, Percentage of mobile fractions calculated from FRAP studies described in (A). Shown is the mean ± S.D. n ≥ 10, *p = 0.0233.