Is actin filament and microtubule growth reaction- or diffusion-limited?. (23rd May 2019)

• Record Type: Journal Article
• Authors: Pausch, Johannes; Pruessner, Gunnar
• Is Part Of: Journal of statistical mechanics. (2019:May)
• Publication Date: 2019-05-23
• Subjects: 16 -- 10; Statistical mechanics -- Periodicals; Mechanics -- Statistical methods -- Periodicals; 530.1305
• DOI: 10.1088/1742-5468/ab081c
• Languages: English
• ISSNs: 1742-5468

Abstract

Abstract: Inside cells of living organisms, actin filaments and microtubules self-assemble and dissemble dynamically by incorporating actin or tubulin from the cell plasma or releasing it into their tips' surroundings. Such reaction-diffusion systems can show diffusion- or reaction-limited behaviour. However, neither limit explains the experimental data: while the offset of the linear relation between growth speed and bulk tubulin density contradicts the diffusion limit, the surprisingly large variance of the growth speed rejects a pure reaction limit. In this article, we accommodate both limits and use a Doi–Peliti field-theory model to estimate how diffusive transport is perturbing the chemical reactions at the filament tip. Furthermore, a crossover bulk density is predicted at which the limiting process changes from chemical reactions to diffusive transport. In addition, we explain and estimate larger variances of the growth speed.