Identification of interaction domains of the prion protein with its 37-kDa/67-kDa laminin receptor. |
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Authors: | Christoph Hundt Stefan Weiss Christoph Hundt Jean-Michel Peyrin Stéphane Haïk Sabine Gauczynski Christoph Leucht Roman Rieger Maria Louise Riley Jean-Philippe Deslys Dominique Dormont Corinne Ida Lasmézas Stefan Weiss |
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Institution: | Laboratorium für Molekulare Biologie-Genzentrum-Institut für Biochemie der LMU München, Feodor-Lynen Strasse 25, D-81377 Munich, Germany. |
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Abstract: | Cell-binding and internalization studies on neuronal and non-neuronal cells have demonstrated that the 37-kDa/67-kDa laminin receptor (LRP/LR) acts as the receptor for the cellular prion protein (PrP). Here we identify direct and heparan sulfate proteoglycan (HSPG)-dependent interaction sites mediating the binding of the cellular PrP to its receptor, which we demonstrated in vitro on recombinant proteins. Mapping analyses in the yeast two-hybrid system and cell-binding assays identified PrPLRPbd1 amino acids (aa) 144-179] as a direct and PrPLRPbd2 (aa 53-93) as an indirect HSPG-dependent laminin receptor precursor (LRP)-binding site on PrP. The yeast two-hybrid system localized the direct PrP-binding domain on LRP between aa 161 and 179. Expression of an LRP mutant lacking the direct PrP-binding domain in wild-type and mutant HSPG-deficient Chinese hamster ovary cells by the Semliki Forest virus system demonstrates a second HSPG-dependent PrP-binding site on LRP. Considering the absence of LRP homodimerization and the direct and indirect LRP-PrP interaction sites, we propose a comprehensive model for the LRP-PrP-HSPG complex. |
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Keywords: | heparan sulfate proteoglycans in vitro interaction 37-kDa laminin receptor precursor 67-kDa high-affinity laminin receptor LRP-PrP-binding domains |
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