Distinct Effects of Recombinant Tenascin-R Domains in Neuronal Cell Functions and Identification of the Domain Interacting with the Neuronal Recognition Molecule F3/11

Authors


  • The authors are indebted to Drs K. L. Guan and J. E. Dixon (Purdue University) for generously providing the vector pGEX-KG, Dr G. Frank (Institute of Molecular Biology, Swiss Federal Institute of Technology) for kindly performing N-terminal amino acid sequencing, and Dr H. Voshol (our department) for helpful discussions on the protein purification with FPLC. Supported by EEC Concerted Action (no. BT02-CT93-0012 to G. R. and M. S.), Association FranGaise contre les Myopathies (to G. R.) and Swiss Multiple Sclerosis Society (to M. S.).

Melitta Schachner, as above

Abstract

We have identified distinct domains of the rat extracellular matrix glycoprotein tenascin-R using recombinant fragments of the molecule that confer neuronal cell functions. In short-term adhesion assays (0.5 h), cerebellar neurons adhered best to the fragment representing the fibrinogen knob (FG), but also the fibronectin type Ill (FN) repeats 1-2 and 6-8. FG, FN1-2 and FN3-5 were the most repellent fragments for neuronal cell bodies. Neurites and growth cones were strongly repelled from areas coated with fragments containing the cysteine-rich stretch and the EGF-like domains (EGF-L), FN1-2, FN3-5 and FG. Polarization of morphology of hippocampal neurons was exclusively associated with FG, while EGF-L prevented neurite outgrowth altogether. The binding site of the neuronal receptor for tenascin-R, the immunoglobulin superfamily adhesion molecule F3/11, was localized to EGF-L. The combined observations show distinct, but also overlapping functions for the different tenascin-R domains. They further suggest the existence of multiple neuronal tenascin-R receptors which influence the response of neurons to their extracellular matrix environment.

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