The F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs) domain of Proline-Serine-Threonine Phosphatase-Interacting Proteins
F-BAR domains are dimerization modules that bind and bend membranes and are found in proteins involved in membrane dynamics and actin reorganization. Vetebrates contain two Proline-Serine-Threonine Phosphatase-Interacting Proteins (PSTPIPs), PSTPIP1 and PSTPIP2. PSTPIPs are mainly expressed in hematopoietic cells and are involved in the regulation of cell adhesion and motility. Mutations in PSTPIPs have been shown to cause autoinflammatory disorders. PSTPIP1 contains an N-terminal F-BAR domain, PEST motifs, and a C-terminal SH3 domain, while PSTPIP2 contains only the N-terminal F-BAR domain. F-BAR domains form banana-shaped dimers with a positively-charged concave surface that binds to negatively-charged lipid membranes. They can induce membrane deformation in the form of long tubules.