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.
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.
Nörenberg
U
U
Max-Delbrück-Centrum für Molekulare Medizin, Berlin, Germany.
Hubert
M
M
Brümmendorf
T
T
Tárnok
A
A
Rathjen
F G
FG
D000818:Animals; D001665:Binding Sites; D002448:Cell Adhesion; D015816:Cell Adhesion Molecules, Neuronal / Q000737:chemistry / Q000378:metabolism*; D002460:Cell Line; D002478:Cells, Cultured; D002642:Chick Embryo; D058966:Contactins; D016326:Extracellular Matrix Proteins / Q000737:chemistry / Q000378:metabolism*; D019006:Neural Cell Adhesion Molecules; D016501:Neurites / Q000502:physiology* / Q000648:ultrastructure; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012160:Retina / Q000166:cytology* / Q000196:embryology; D019063:Tenascin; D014162:Transfection
D015816:Cell Adhesion Molecules, Neuronal; D058966:Contactins; D016326:Extracellular Matrix Proteins; D019006:Neural Cell Adhesion Molecules; D011993:Recombinant Fusion Proteins; D019063:Tenascin; C074638:tenascin R