Enhanced diffusion in active intracellular transport.
We show that within a living eukaryotic cell, mean square displacement of an engulfed microsphere shows enhanced diffusion scaling as t(3/2) at short times, with a clear crossover to subdiffusive or ordinary diffusion scaling at longer times. The motion, observed nearby the nucleus, is due to interactions with microtubule-associated motor proteins rather than thermal Brownian motion. We propose that time-dependent friction introduced by the intracellular polymer networks leads to sub-ballistic motion, analogous to subdiffusion observed in passive networks of semiflexible biopolymers.
Caspi
A
A
Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot 76100, Israel.
Granek
R
R
Elbaum
M
M
D000465:Algorithms; D001693:Biological Transport, Active; D002478:Cells, Cultured; D004058:Diffusion; D005347:Fibroblasts / Q000378:metabolism* / Q000648:ultrastructure; D005455:Fluorescent Antibody Technique; D008863:Microspheres; D020409:Molecular Motor Proteins / Q000502:physiology; D011137:Polystyrenes / Q000378:metabolism; D012212:Rheology
D020409:Molecular Motor Proteins; D011137:Polystyrenes