Shape transition from elliptical to cylindrical membrane tubes induced by chiral crescent-shaped protein rods

TL;DR

This study uses simulations to explore how chiral crescent-shaped proteins induce a transition from elliptical to cylindrical membrane tubes, revealing the role of chirality in membrane shape regulation.

Contribution

It demonstrates how chiral protein rods induce a cylindrical membrane shape through helical assembly, a novel insight into membrane-protein interactions.

Findings

Chiral rods form helical assemblies stabilizing cylindrical tubes.

Achiral rods deform membranes into elliptical shapes.

Results align with experimental observations of BAR proteins.

Abstract

Proteins often form chiral assembly structures on a biomembrane. However, the role of the chirality in the interaction with an achiral membrane is poorly understood. Here, the differential behavior between chiral and achiral crescent-shaped protein rods was investigated using meshless membrane simulations. The achiral rods deformed the membrane tube into an elliptical shape by stabilizing the edges of the ellipse. In contrast, the chiral rods formed a helical assembly that generated a cylindrical membrane tube with a constant radius in addition to the elliptical tube. This helical assembly could be further stabilized by the direct side-to-side attraction between the protein rods. These results agree with experimental findings of the constant radius of membrane tubules induced by the Bin/Amphiphysin/Rvs (BAR) superfamily proteins.