Motor-driven microtubule diffusion in a photobleached dynamical coordinate system

• 成果类型: Article
• 署名作者: Hirokawa, Soichi; Lee, Heun Jin; Banks, Rachel A.; Duarte, Ana I.; Najma, Bibi; Thomson, Matt; Phillips, Rob
• 署名单位: California Institute of Technology; California Institute of Technology; California Institute of Technology; Aix-Marseille Universite; Centre National de la Recherche Scientifique (CNRS)
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-12451
• DOI: 10.1073/pnas.2417020122
• 发表日期: 2025-06-09
• 关键词: fluorescence recovery; self-organization; active-matter; kinesin; motion; fluctuations; contribute; transport; MOVEMENT; motility

摘要

A hallmark feature of active matter systems is the ability of individual elements to interact and organize over length scales exceeding that of the constituent molecular players. However, the nature of internal redistribution that occurs in the bulk of the collective is less clear. Using light-dimerizable kinesin motors to spatially control the formation and contraction of a microtubule network, we deliberately photobleach a grid pattern onto the filament network serving as a transient and dynamic coordinate system to observe the deformation and translation of the remaining fluorescent squares of microtubules. We find that the network contracts at a rate set by motor speed but is accompanied by a diffusive-like spread throughout the bulk of the contracting network with effective diffusion constant two orders of magnitude lower than that for freely diffusing microtubules. We further find that on micron scales, the diffusive timescale is only a factor of approximate to 3 slower than that of advection regardless of conditions, showing that the global contraction and long-time relaxation from this diffusive behavior are both motor-driven but exhibit local competition within the network bulk.