Patterns of molecular motors that guide and sort filaments

Abstract

Molecular motors can be immobilized to transport filaments and loads that are attached to these filaments inside a nano-device. However, if motors are distributed uniformly over a flat surface, the motility is undirected, and the filaments move equally in all directions. For many applications it is important to control the direction in which the filaments move, and two strategies have been explored to achieve this: applying external forces and confining the filaments inside channels. In this article, we discuss a third strategy in which the topography of the sample remains flat, but the motors are distributed non-uniformly over the surface. Systems of filaments and patterned molecular motors were simulated using a stochastic engine that included Brownian motion and filament bending elasticity. Using an evolutionary algorithm, patterns were optimized for their capacity to precisely control the paths of the filaments. We identified patterns of motors that could either direct the filaments in a particular direction, or separate short and long filaments. These functionalities already exceed what has been achieved with confinement. The patterns are composed of one or two types of motors positioned in lines or along arcs and should be easy to manufacture. Finally, these patterns can be easily combined into larger designs, allowing one to precisely control the motion of microscopic objects inside a device.

Chromosomes function as a barrier to mitotic spindle bipolarity in polyploid cells

“…MTs were considered as flexible polymers with static minus ends and dynamic plus ends that could grow and shrink according to the dynamic instability model (Gittes et al, 1993; Dogterom and Yurke, 1997; Gallaud et al, 2014). The kinesin motors Ncd were represented as entities composed of two separate MT-binding “heads,” one static (corresponding to the nonmotor domain) and one that could move toward the MT minus ends (Howard et al, 1989; Oladipo et al, 2007; Rupp and Nédélec, 2012; Letort et al, 2019). Ncd was shown to bind and slide anti-parallel MTs and cross-link parallel MTs (Fink et al, 2009).…”

A Motor-Gradient and Clustering Model of the Centripetal Motility of MTOCs in Meiosis I of Mouse Oocytes

“…A mechanistically detailed model was developed using Cytosim [ 41 ], a C++ Langevin dynamics simulation engine, by building on previously developed models of MT-mechanics [ 14 , 42 ], polymerization kinetics [ 7 , 25 ] and motor interactions [ 20 – 24 , 26 , 27 , 43 ]. To test what minimal components will produce the observed centripetal motility of MTOC asters, a model of an MT stabilization gradient described previously [ 27 ] was developed by mapping the gradient shape optimized in the RWD model.…”

Magnetic Quantum Dots Steer and Detach Microtubules From Kinesin‐Coated Surfaces

“…MT motion can also be regulated by controlling access to ATP fuel; however, these strategies are inherently limited by finite fuel supply, even when availability is regulated . MT motion can also be altered by passive guidance using patterned topographical or chemical features that permit MT motion only along predefined tracks . Typically, these strategies require surface patterning or microfluidics.…”