Work

Molecular Flexibility and Electrostatic Interactions Drive the Nanoscale Structure of Coiled-Coil GM130 Protein Condensates

Year: 2026

Type: article

Abstract: Golgins are coiled-coil proteins that decorate Golgi with highly specific spatial distribution acting as vesicle tethers through their extended, semiflexible architectures. Among them, GM130 is also known to undergo phase separation, yet the molecular basis of this behavior remains poorly understood. Here, we use atomic force microscopy (AFM) to directly visualize individual GM130 molecules adsorbed onto attractive surfaces. We find that GM130 is highly flexible and undergoes conformational transitions from extended chains to collapsed coils—globular structures that serve as building blocks for the submicrometric two-dimensional and dynamic domains when anchored to lipid bilayers. Molecular-dynamics simulations predict a supramolecular scaffold for GM130 domains composed of coiled-coil intermolecular nodes surrounded by a dispersed phase of intrinsically disordered regions with electrostatic interactions acting as chief drivers of phase-separation. These assemblies are experimentally validated under high-force AFM measurements. Our findings establish the structural basis linking GM130 conformational polymorphism to its phase separation capacity.

Source: PRX Life

DOI: 10.1103/lp87-svtc