Figure 3.

Spatial relationship of actin organization to the presence or absence of PIP3 in the underlying membrane. The diagram represents a line scan through an actin wave pattern on a planar glass surface. On top, the relationship of actin- and PIP3-labels is shown. The fluorescence intensity of actin (red) peaks at the position of the wave formed at the border of a PIP3-rich area of the cell membrane (green). Horizontal arrows point into the changing directions of wave propagation. On the bottom, actin structures are shown to differ between the PIP3-rich area circumscribed by the wave and the external area depleted of PIP3. The Arp2/3 complex known to nucleate branches of actin filaments dominates in the PIP3-rich area, while proteins associated with anti-parallel bundles of filaments are prevailing in the external area. This diagram summarizes data published in [5] and [7].