Fig. 5. Immunolocalization of myosin II and phosphorylated myosin light chain (P-MLC) in ruffles and phagocytic cups of macrophages. Immunofluorescence of myosin II (A) and P-MLC (B) in macrophages stimulated with M-CSF showed that MLC of myosin II are predominantly phosphorylated in cell-surface ruffles. (C,D) In control macrophages phagocytosing IgG-Es (7 minutes after feeding with IgG-Es), P-MLC localized in some phagocytic cups (arrows) but not in phagosomes (open arrows). (E,F) ML-7 treatment greatly reduced the amount of P-MLC in phagocytic cups. Phase-contrast images C and E correspond to fluorescence images D and F, respectively. Bars, 10 µm.