Membrane curvature sensed and induced by formin binding Protein 17.

Cell functions such as motility, differentiation, protein trafficking or signal transduction, often require some membrane reshaping events involving a change in membrane curvature and protein distribution. Defects associated with the proteins involved in membrane reshaping can cause several diseases such as centronuclear myopathy or Charcot-Marie-Tooth neuropathies. Among the proteins associated with alteration in membrane curvature, BAR (Bin/Amphiphysin/Rvs) domain proteins stand out. BAR domain proteins are crescent shaped dimeric structures that bind to lipid bilayers through electrostatic interactions. These curvature sensitive proteins are capable of inducing both local and global curvatures. However, the complexity of the mechanisms of the interactions between these proteins and lipid bilayers are not well known. Computational studies of these protein-membrane interactions using molecular dynamics are often coarse-grained as opposed to all-atoms simulations. In the present study, we explore the curvature sensitivity and inducing properties of Formin Binding Protein 17 (fbp17) through all-atoms molecular dynamics simulations. We simulated fbp17 with different lipid bilayer compositions on flat and buckled bilayers. We were able to isolate the residues involved in the interactions. Our results suggest that fbp17 can induce a certain range of local curvature on various flat membranes. Fp17 can also sense or conform to various ranges of curved bilayers. These results give an insight into the role of BAR domain protein in general, and fbp17 in particular in the context of membrane structural fluctuations.