Figure 1.

Surface view of a plasma membrane of a chemotaxing cell showing the portion of the feed-forward events studied. (1) Activated PKCα (PKC^∗, green ellipse) phosphorylates the effector domain of MARCKS (red squiggly line) on at least one site resulting in (2) dissociation of MARCKS from the membrane surface and the dissociation of the sequestered PIP₂ (blue circles) into other regions of the plasma membrane. (3) PIP₂ acts as an activator and substrate of PI3K (yellow hexagon) to produce PIP₃ (brown circles), causing a further series of events that results in actin rearrangement (4) and forward movement. To see this figure in color, go online.