An in vitro model system for cytoskeletal confinement.
The motility, shape, and functionality of the cell depend sensitively on cytoskeletal mechanics which in turn is governed by the properties of filamentous proteins - mainly actin, microtubules, and intermediate filaments. These biopolymers are confined in the dense cytoplasm and therefore experience strong geometric constraints on their equilibrium thermal fluctuations. To obtain a better understanding of the influence of confinement on cytoskeletal filaments we study the thermal fluctuations of individual actin filaments in a microfluidic in vitro system by fluorescence microscopy and determine the persistence length of the filaments by analyzing the radial distribution function. A unique feature of this method is that we obtain the persistence length without detailed knowledge of the complete contour of the filament which makes the technique applicable to a broad range of biological polymers, including those with a persistence length smaller than the optical resolution.
Köster
Sarah
S
Dynamics of Complex Fluids, Max Planck Institute for Dynamics and Self-Organization, 37073 Göttingen, Germany. sarah.koester@phys.uni-goettingen.de
Pfohl
Thomas
T
D008841:Actin Cytoskeleton / Q000648:ultrastructure*; D000818:Animals; D001696:Biomechanical Phenomena; D003599:Cytoskeleton / Q000648:ultrastructure*; D007382:Intermediate Filaments; D044085:Microfluidics / Q000295:instrumentation; D008856:Microscopy, Fluorescence; D008954:Models, Biological