Intrinsically disordered proteins drive membrane curvature

Area of Science:

• Cell Biology
• Biophysics
• Protein Science

Background:

• Cellular membrane curvature is crucial for physiological processes.
• Previously, structured protein motifs like BAR domains were thought essential for membrane bending.

Purpose of the Study:

• To investigate the role of intrinsically disordered domains in driving membrane curvature.
• To explore the mechanism by which these domains influence membrane bending.

Main Methods:

• In vitro measurements of membrane curvature and protein diffusivity.
• Expression of disordered adaptor domains as transmembrane cargo in mammalian cells.

Main Results:

• Intrinsically disordered domains of Epsin1 and AP180 potently drive membrane curvature.
• Steric pressure from the large hydrodynamic radii of these domains induces membrane bending.
• Disordered domains were excluded from clathrin-coated pits in mammalian cells.

Conclusions:

• Intrinsically disordered domains are significant drivers of membrane curvature.
• Steric pressure is a key factor influencing membrane bending and cellular structure assembly.
• A balance of steric pressure likely governs the exclusion of proteins from specific membrane domains.