Comparison of the level of myosin II assembly in cells over-expressing full-length MHCK-B, MHCK-B-Δ-WD, or MHCK-Δ-N-WD. (A) Immunoblot of pellet (P) and supernatant (S) fractions from cytoskeletal fractionation assays performed as described previously [6, 13]. The background Dictyostelium cell lines are indicated above each bracket and the over-expressed protein is indicated within the brackets and above each corresponding P and S pair. Myosin II heavy chain was detected in the fractions using polyclonal antibody specific the heavy chain. (B) The relative amount of myosin II (244 kDa MHC band) in the P and S fractions was quantified desnsitometrically from Western blots as described previously [6, 13], and the percent total myosin II in the cytoskeleton-enriched fraction was calculated by dividing the densitometry value for the P fraction by the sum of those for the P and S fractions and then multiplying by 100 percent. The bars represent the average values from four separate experiments and the vertical lines are the standard errors of those means.