Assembly and Flux of Myosin II in the Lamella of Fiborblasts

McKenna et al., J. Cell Biol. 109:1163-1172 (1989)

Myosin II interacts with actin filaments to generate contractile forces. To investigate the formation of myosin structures in cultured non-muscle cells, we microinjected fluorescently labeled smooth muscle myosin II into living 3T3 fibroblasts.

Assembly and Rearward Transport of Myosin II Minifilaments in Motile Cells

These video sequences show the continuous formation of myosin punctate structures behind an active lamellipodium, and subsequent movement toward the center of the cell. These structures are known to consist of side-by-side, ribbon-like complexes of myosin molecules. Although not visible in these images, they most likely disassemble somewhere near the center of the cell, releasing myosin subunits back to the anterior end to sustain the assembly activity. Recording time, 20 min.

Organization of Myosin II Minifilaments into Lattice

This sequence shows the organization of myosin punctate structures into a two-dimensional lattice. Recording time, 60 min.