Chronology of motor-mediated microtubule streaming

Abstract

We introduce a filament-based simulation model for coarse-grained, effective motor-mediated interaction between microtubule pairs to study the time-scales that compose cytoplasmic streaming. We characterise microtubule dynamics in two-dimensional systems by chronologically arranging five distinct processes of varying duration that make up streaming, from microtubule pairs to collective dynamics. The structures found were polarity sorted due to the propulsion of antialigned microtubules. This also gave rise to the formation of large polar-aligned domains, and streaming at the domain boundaries. Correlation functions, mean squared displacements, and velocity distributions reveal a cascade of processes ultimately leading to microtubule streaming and advection, spanning multiple microtubule lengths. The characteristic times for the processes extend over three orders of magnitude from fast single-microtubule processes to slow collective processes. Our approach can be used to directly test the importance of molecular components, such as motors and crosslinking proteins between microtubules, on the collective dynamics at cellular scale.

Growth rate-dependent flexural rigidity of microtubules influences pattern formation in collective motion

“…A similar opinion was proposed that self-propelled objects, such as gilding MTs, show progressively larger probabilities to align with their neighbors [ 66 ]. Recently, an important supplement to these hypotheses stated that MTs align and are actively transferred from their original bundle to another anti-aligned bundle [ 67 ]. All the theories indicated that alignment is a critical step in the formation of collective motion, and the formation of MT bundles is a dynamic process.…”

Extending the analogy between intracellular motion in mammalian cells and glassy dynamics

“…3; note the y axis log scale). 14,23,[39][40][41][42][43][44][45][46][47][48] Interestingly, the exponentially decaying tails appear to be there also for shorter timescales (Fig. S4, ESI †), though the statistics is necessarily poorer.…”

Structure and dynamics of an active polymer adsorbed on the surface of a cylinder

“…13 Moreover, microfilaments, which are regarded as thin and long polymer chains, show a tread-milling motion in the ATP solution 14 or associate with motor proteins. [15][16][17] To understand how an active force governs the non-equilibrium dynamics of biopolymers, an active polymer model has been proposed recently, 18,19 where a self-propulsion force is imposed tangentially on the polymer. The active polymer displays a rich phenomenology 20,21 such as super-diffusion, rotational motion, helical motion, 22,23 and collective motion.…”