Mechanochemical action of the dynamin protein

TL;DR

This paper develops a hydrodynamics model to understand how dynamin proteins change conformation and cause membrane tubulation, incorporating GTP energy consumption and friction effects, with predictions testable experimentally.

Contribution

It introduces a generalized hydrodynamics framework for dynamin conformational changes, including GTP-driven energy use and friction, advancing understanding of membrane severing mechanisms.

Findings

Deformation dynamics follow a diffusive behavior.

Model predicts membrane tube behavior consistent with some experimental results.

Semi-microscopic model explains complex conformational changes and supercoiling.

Abstract

Dynamin is a ubiquitous GTPase that tubulates lipid bilayers and is implicated in many membrane severing processes in eukaryotic cells. Setting the grounds for a better understanding of this biological function, we develop a generalized hydrodynamics description of the conformational change of large dynamin-membrane tubes taking into account GTP consumption as a free energy source. On observable time scales, dissipation is dominated by an effective dynamin/membrane friction and the deformation field of the tube has a simple diffusive behavior, which could be tested experimentally. A more involved, semi-microscopic model yields complete predictions for the dynamics of the tube and possibly accounts for contradictory experimental results concerning its change of conformation as well as for plectonemic supercoiling.