Membrane Sculpting by F-BAR Domains Studied by Molecular Dynamics Simulations
Hang Yu

October 31, 2012

Interplay between cellular membranes and their peripheral proteins drives many processes in eukaryotic cells. Proteins of the Bin/Amphiphysin/Rvs (BAR) domain family, in particular, play a role in cellular morphogenesis, for example curving planar membranes into tubular membranes. However, it is still unclear how F-BAR domain proteins act on membranes. Electron microscopy revealed that, in vitro, F-BAR proteins form regular lattices on cylindrically deformed membrane surfaces. Using all-atom and coarse-grained (CG) molecular dynamics simulations, we show that such lattices, indeed, induce tubes of observed radii. A 250 ns all-atom simulation reveals that F-BAR domain curves membranes via the so-called "scaffolding" mechanism. Plasticity of the F-BAR domain permits conformational change in response to membrane interaction, via partial unwinding of the domain's 3-helix bundle structure. A CG simulation covering more than 350 us provides a dynamic picture of membrane tubulation by lattices of F-BAR domains. A series of CG simulations identified the optimal lattice type for membrane sculpting, which matches closely the lattices seen through cryo-electron microscopy.

Hang Yu currently holds a BS with Honors, Biology/Computing, 2007 from Nanyang Technological University, Singapore. He is pursuing graduate studies in BioPhysics at the University of Illinois with an interest in BAR domains.

The Beckman Institute at Illinois is a world-class interdisciplinary facility devoted to ground-breaking research in the physical sciences, computation, engineering, biology, behavior, cognition, and neuroscience.