FIG. 6.

C terminus deletion mutations reveal a potential negative autoregulatory region in MRCKα. (A) pXJ40-FLAG-tagged constructs were transfected into COS-7 cells, and expressed proteins were immunoprecipitated (IP) with anti-FLAG antibody for kinase assay using GST-MLC2 as the substrate (left side). The quantified phosphorylation levels are shown on the right as the means and standard errors of activities relative to the wild-type (w/t) level (taken as 1) from three independent experiments. WB, Western blot. (B) Effects of overexpression of the C terminus deletion mutant constructs on actin filament rearrangement in HeLa cells. Cells were doubly stained with anti-FLAG antibody to show transfected cells (left) and phalloidin to show actin filaments (right). Transfected cells were marked with asterisks. Scale bar = 10 μm.