Figure 1.

Architecture of peripheral arcs. (A) Fluorescence images of REF-52 cells on cross-shaped patterns, showing isoforms IIa (top row) or IIb (bottom row) of nonmuscle myosin II, α-actinin, and F-actin. The last column is a merge of all three proteins (myosin in red, α-actinin in green, actin in blue, and the contour of the adhesive pattern is shown in magenta). Scale bar, 10 μm. (B) Intensity profiles along one arc of actin (black), α-actinin (red), and myosin (blue), showing multiple zones rich in myosin II and α-actinin. Profiles were normalized by the mean intensity over the bundle length. Note that no periodic bands were observed. The corresponding bundles and the scanning direction are indicated (^∗, ^∗∗, or yellow arrows) in (A). Bundle lengths are 40 μm (^∗) and 50 μm (^∗∗).