Figure 11

Schematic depiction of differential localization of MHCK-A, -B and -C (in the presence of myosin II) in D. discoideum cells during free migration (A), early stage of cytokinesis (B), and at the completion of cytokinesis (C). In migrating cells, MHCK-C (red dots) colocalizes with myosin II (blue dots) at the posterior region. MHCK-A (green dots), on the other hand, colocalizes with actin at the front protrusions. MHCK-B distributes homogeneously in the cytoplasm (yellow fill). In the early stage of cytokinesis, myosin II concentrates to the furrow. However, MHCK-A (and sometimes MHCK-C) localizes to the polar protrusions (pseudopods) while MHCK-B is always cytosolic throughout the cell with some exclusion from the furrow region. At the late stages of cytokinesis, MHCK-C is recruited to the furrow region, and persists at this location after the completion of division. This persistent localization is reflected as posterior localization in the two new daughter cells, where MHCK-C presumably to help disassemble myosin II thick filaments that have completed their role in furrow contraction.