Nervous Wreck forms zig-zags to induce membrane ridges and scallops.

Em:LM Nwk F-BAR S2

Merged LM/EM images of Drosophila S2 cells featuring Nwk F-BAR induced protrusions.

Sorting and processing of the proteins that span cell membranes requires extensive membrane remodeling , including budding, tubulation, and fission. F-BAR domains form crescent-shaped dimers that bind to and deform membranes. Until now, it was thought that proteins containing these F-BAR domains induced membrane tubulation by assembling in highly ordered helical coats on lipid bilayers.

A new paper in Molecular Biology of the Cell from the Rodal lab (in collaboration with the Nicastro lab and the Sokolova Lab at Lomonosov Moscow State University) describes a novel membrane deforming activity for Nervous Wreck (Nwk), an F-BAR protein that regulates trafficking of transmembrane growth signal receptors at the Drosophila neuromuscular junction. The authors found that Nwk assembles into zig-zags on lipid monolayers, unlike the canonical F-BAR protein CIP4 which forms long filaments, even though the two proteins are predicted to be very structurally similar.  Unlike other members of the F-BAR family that tubulate the membrane, Nwk can induce the formation of membrane ridges and scallops (see figure below). These deformations can lead to dramatic cellular remodeling in cooperation with the cytoskeleton (see figure above). The work done by the Rodal lab suggests that while basic self-assembly and membrane binding properties are likely conserved between F-BAR proteins, the higher-order organization of Nwk may account for differences in membrane remodeling and its specialized role in the cell.

Nwk Model

Protected by Akismet
Blog with WordPress

Welcome Guest | Login (Brandeis Members Only)