Pivot-and-bond model explains microtubule bundle formation

Scientific paper - Original scientific paper

• Author: Marcel Prelogović; MBZ: 342476
• Author: Lora Winters
• Author: Ana Milas
• Author: Iva Tolić
• Author: Nenad Pavin; MBZ: 204800
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract (english)

During mitosis, microtubules form a spindle, which is responsible for proper segregation of the genetic material. A common structural element in a mitotic spindle is a parallel bundle, consisting of two or more microtubules growing from the same origin and held together by cross-linking proteins. An interesting question is what are the physical principles underlying the formation and stability of such microtubule bundles. Here we show, by introducing the pivot-and-bond model, that random angular movement of microtubules around the spindle pole and forces exerted by cross-linking proteins can explain the formation of microtubule bundles as observed in our experiments. The model predicts that stable parallel bundles can form in the presence of either passive crosslinkers or plus-end directed motors, but not minus-end directed motors. In the cases where bundles form, the time needed for their formation depends mainly on the concentration of cross-linking proteins and the angular diffusion of the microtubule. In conclusion, the angular motion drives the alignment of microtubules, which in turn allows the cross-linking proteins to connect the microtubules into a stable bundle.

• Keywords (english): Diffusion; Mitosis; Self-organisation; Cytoskeleton; Confocal imaging; Fokker-Planck equation; Langevin equation
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Physical Review E
• Numbering: vol. 100, no. 1, 012403
• p-ISSN: 2470-0045
• e-ISSN: 2470-0053
• DOI: https://doi.org/10.1103/PhysRevE.100.012403
• URN:NBN: urn:nbn:hr:217:834769
• Publication: 2019
• Document URL: https://journals.aps.org/pre/abstract/10.1103/PhysRevE.100.012403
• Type of resource: Text
• Access conditions: Open access
• Public note: © 2019 American Physical Society. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Received 18 April 2017. Revised 24 April 2019. Published 9 July 2019.
• Created on: 2020-08-24 12:17:33