Characterization of functional domains of the tenascin-R (restrictin) polypeptide: cell attachment site, binding with F11 and enhancement of F11 mediated neurite outgrowth by tenascin-R


  • U. Noerenberg
  • M. Hubert
  • T. Bruemmendorf
  • A. Tarnok
  • F.G. Rathjen


  • Journal of Cell Biology


  • J Cell Biol 130 (2): 473-484


  • The extracellular matrix glycoprotein tenascin-R (TN-R) is a multidomain protein implicated in neural cell adhesion. To analyze the structure-function relationship of the different domains of TN-R, several recombinant TN-R fragments were expressed in bacterial cells. Two distinct binding regions were localized on the TN-R polypeptide: a region binding the axon-associated immunoglobulin (Ig)-like F11 protein and a cell attachment site. The binding region of the glycosylphosphatidylinositol (GPI)-anchored F11 was allocated to the second and third fibronectin type III (FNIII)-like domain within TN-R. By using a mutant polypeptide of F11 containing only Ig-like domains, a direct interaction between the Ig-like domains of F11 and FNIII-like domains 2-3 of TN-R was demonstrated. The interaction of TN-R with F11 in in vitro cultures enhanced F11-mediated neurite outgrowth, suggesting that the combined action of F11 and TN-R might be of regulatory influence on axon extension. A cell attachment region was identified in the FNIII-like domain eight of TN-R by domain-specific antibodies and fusion constructs. This site is distinct from the F11 binding site within TN-R.