Structures and pathways for clathrin self-assembly in the bulk and on membranes

TL;DR

This study introduces a simplified coarse-grained model of clathrin that captures key assembly behaviors in bulk and on membranes, revealing pathways for cage formation and membrane budding through simulations.

Contribution

The paper presents a new computational model of clathrin that efficiently simulates its self-assembly and membrane interactions, including a novel membrane boundary condition for dynamics.

Findings

Reproduces known clathrin structures in simulations

Identifies membrane budding pathway via cluster coalescence

Demonstrates model's ability to simulate bulk and membrane assembly

Abstract

We present a coarse-grained model of clathrin that is simple enough to be computationally tractable yet includes key observed qualitative features: a triskelion structure with excluded volume between legs; assembly of polymorphic cages in the bulk; formation of buds on a membrane. We investigate the assembly of our model using both Monte Carlo simulations and molecular dynamics with hydrodynamic interactions, in the latter employing a new membrane boundary condition. In the bulk, a range of known clathrin structures are assembled. A membrane budding pathway involving the coalescence of multiple small clusters is identified.