Figure 4.

Nonextractable KIF3B colocalizes with skeletal muscle myosin in differentiating C2C12 cells. (A and B) Confocal image of C2C12 myotube that has been double labeled with an antibody to skeletal muscle myosin (A, red) and α-KIF3B-T (B, green). Before methanol fixation, the myotube was extracted with 0.5% Triton X-100 in microtubule-stabilizing buffer for 1 min. Merge of images is shown in C. Patches of skeletal muscle myosin, being assembled into myofibrils (arrows in A) colocalize with nonextractable accumulations of KIF3B (arrows in B). Yellow in C demonstrates colocalization of the two markers under these conditions. Bar, 20 μm.