Pinkbar is an epithelial-specific BAR domain protein that generates planar membrane structures

Nat Struct Mol Biol. 2011 Jul 10;18(8):902-7. doi: 10.1038/nsmb.2079.


Bin/amphipysin/Rvs (BAR)-domain proteins sculpt cellular membranes and have key roles in processes such as endocytosis, cell motility and morphogenesis. BAR domains are divided into three subfamilies: BAR- and F-BAR-domain proteins generate positive membrane curvature and stabilize cellular invaginations, whereas I-BAR-domain proteins induce negative curvature and stabilize protrusions. We show that a previously uncharacterized member of the I-BAR subfamily, Pinkbar, is specifically expressed in intestinal epithelial cells, where it localizes to Rab13-positive vesicles and to the plasma membrane at intercellular junctions. Notably, the BAR domain of Pinkbar does not induce membrane tubulation but promotes the formation of planar membrane sheets. Structural and mutagenesis analyses reveal that the BAR domain of Pinkbar has a relatively flat lipid-binding interface and that it assembles into sheet-like oligomers in crystals and in solution, which may explain its unique membrane-deforming activity.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Motifs
  • Animals
  • Binding Sites
  • Cell Membrane / metabolism*
  • Cell Membrane / ultrastructure
  • Crystallography, X-Ray
  • Cytoplasmic Vesicles / metabolism
  • Epithelium / metabolism*
  • Intercellular Junctions / metabolism
  • Intestinal Mucosa / metabolism
  • Intestines / cytology
  • Kidney / cytology
  • Kidney / metabolism
  • Membrane Proteins / analysis
  • Membrane Proteins / chemistry
  • Membrane Proteins / physiology*
  • Mice
  • Models, Molecular
  • Mutagenesis, Site-Directed
  • Protein Structure, Tertiary
  • Unilamellar Liposomes / metabolism
  • rab GTP-Binding Proteins / metabolism


  • Membrane Proteins
  • Unilamellar Liposomes
  • pinkbar protein, mouse
  • Rab13 protein, mouse
  • rab GTP-Binding Proteins

Associated data

  • PDB/3OK8