Dynamin recruitment by clathrin coats: a physical step?

TL;DR

This paper proposes a physical model where dynamin proteins induce membrane curvature and interact elastically, leading to their recruitment around vesicle necks during endocytosis, providing insight into the mechanical aspects of dynamin function.

Contribution

It introduces a novel physical mechanism explaining dynamin recruitment via membrane elasticity and curvature imprinting, supported by theoretical calculations.

Findings

Dynamins can induce local membrane curvature upon insertion.

Elastic interactions can lead to dynamin collar formation around vesicle necks.

The model aligns with observed dynamin recruitment during endocytosis.

Abstract

Recent structural findings have shown that dynamin, a cytosol protein playing a key-role in clathrin-mediated endocytosis, inserts partly within the lipid bilayer and tends to self-assemble around lipid tubules. Taking into account these observations, we make the hypothesis that individual membrane inserted dynamins imprint a local cylindrical curvature to the membrane. This imprint may give rise to long-range mechanical forces mediated by the elasticity of the membrane. Calculating the resulting many-body interaction between a collection of inserted dynamins and a membrane bud, we find a regime in which the dynamins are elastically recruited by the bud to form a collar around its neck, which is reminiscent of the actual process preempting vesicle scission. This physical mechanism might therefore be implied in the recruitment of dynamins by clathrin coats.