Buckling and force propagation along intracellular microtubules

TL;DR

This paper presents a theoretical study of how microtubules buckle and transmit forces within cells, revealing the influence of the surrounding cytoskeleton's nonlinear properties on deformation and force propagation range.

Contribution

It introduces a model for force propagation along microtubules embedded in a nonlinear elastic medium, highlighting the effects of mechanical coupling and material properties.

Findings

Buckling occurs when load exceeds critical force $f_c$.

Deformation penetration depth depends on cytoskeleton properties.

Force transmission range can reach tens of microns.

Abstract

Motivated by recent experiments showing the buckling of microtubules in cells, we study theoretically the mechanical response of, and force propagation along elastic filaments embedded in a non-linear elastic medium. We find that, although embedded microtubules still buckle when their compressive load exceeds the critical value $f_c$ found earlier, the resulting deformation is restricted to a penetration depth that depends on both the non-linear material properties of the surrounding cytoskeleton, as well as the direct coupling of the microtubule to the cytoskeleton. The deformation amplitude depends on the applied load $f$ as $(f- f_c)^{1/2}$. This work shows how the range of compressive force transmission by microtubules can be as large as tens of microns and is governed by the mechanical coupling to the surrounding cytoskeleton.