Pivot-and-bond model explains microtubule bundle formation

Prelogović, Marcel; Winters, Lora; Milas, Ana; Tolić, Iva M.; Pavin, Nenad (2019) Pivot-and-bond model explains microtubule bundle formation. Physical Review E, 100 (1). ISSN 2470-0045

Preview

PDF - Published Version - article Available under License Creative Commons Attribution. Download (1MB) | Preview

Abstract

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.

Item Type:	Article
Uncontrolled Keywords:	diffusion; mitosis; cytoskeleton; confocal imaging; Fokker–Planck equation; Langevin equation; Ruđer Bošković Institute
Subjects:	NATURAL SCIENCES > Physics > Biophysics and Medical Physics
Divisions:	Division of Molecular Biology
Depositing User:	Kruno Vukušić
Date Deposited:	12 Oct 2020 11:17
URI:	http://fulir.irb.hr/id/eprint/5961
DOI:	10.1103/PhysRevE.100.012403

Actions (login required)

View Item