Internal motility in stiffening actin-myosin networks
Jörg Uhde1, Manfred Keller, Erich Sackmann
1Physik Department, Technische Universität München, D-85747 Garching, Germany.
Abstract:
We present a study on filamentous actin solutions containing heavy meromyosin subfragments of myosin II motor molecules. We focus on the viscoelastic phase behavior and internal dynamics of such networks during adenosine-triphosphate depletion. By combining microrheology and fluorescence microscopy, we observed a sol-gel transition accompanied by a sudden onset of directed filament motion. We interpret the sol-gel transition in terms of myosin II enzymology, and suggest a "zipping" mechanism to explain the filament motion in the vicinity of the sol-gel transition.
Related Concept Videos
The Role of Actin and Myosin in Non-muscle Cells
Formation of Higher-order Actin Filaments
The high-order actin networks...
Actin and Myosin in Muscle Contraction
Generation of Straight or Branched Actin Filaments
Arp2/3 Complex
Arp2/3 complex is a seven-subunit complex consisting of two proteins similar to actin- Arp2 and Arp3, and five other subunits that help keep Arp2 and Arp3 inactive. When required, the complex is...
Actin Polymerization and Cell Motility
Actin cytoskeleton dynamics can produce pushing, pulling, and resistance forces that help the cell to migrate.
Role of Myosin in Cell Migration
Myosin II is a hexamer comprising two heavy chains with globular heads and coiled-coil tails, two regulatory light chains, and two essential light chains. The ATPase sites on the myosin heads hydrolyze ATP, and the released phosphate generates the force for contraction. It is...


