Observation and kinematic description of long actin tracks induced by spherical beads.
We report an in vitro study comparing the growth of long actin tails induced by spherical beads coated with the verprolin central acidic domain of the polymerization enzyme N-WASP to that induced by Listeria monocytogenes in similar cellular extracts. The tracks behind the beads show characteristic differences in shape and curvature from those left by the bacteria, which have an elongated shape and a similar polymerization-inducing enzyme distributed only on the rear surface of the cell. The experimental tracks are simulated using a generalized kinematic model, which incorporates three modes of bead rotation with respect to the tail. The results show that the trajectories of spherical beads are mechanically deterministic rather than random, as suggested by stochastic models. Assessment of the bead rotation and its mechanistic basis offers insights into the biological function of actin-based motility.
Department of Physics, Brown University, Providence, Rhode Island, USA.
Hyeran
H
Kang
David S
DS
Perlmutter
Vivek B
VB
Shenoy
Jay X
JX
Tang
D000199:Actins / Q000502:physiology*; D000818:Animals; D001696:Biomechanical Phenomena; D055592:Biophysical Phenomena; D066298:In Vitro Techniques; D008089:Listeria monocytogenes / Q000502:physiology; D018613:Microscopy, Confocal; D008858:Microscopy, Phase-Contrast; D018715:Microscopy, Video; D008954:Models, Biological; D009068:Movement / Q000502:physiology; D010316:Particle Size; D011137:Polystyrenes; D011817:Rabbits; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal / Q000502:physiology
D000199:Actins; D011137:Polystyrenes; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal