Interaction between various PrP segments and GFAP in vitro

OBJECTIVE: To study the potential interaction between PrP protein and glial fibrillary acidic protein (GFAP) and identify the binding region within PrP with GFAP. METHODS: The supernatant of healthy and scrapie-infected hamsters' brain homogenate was prepared, while various recombinant PrP or GFAP proteins were expressed using prokaryotic-expressing or in-vitro translation system. The possible molecular interaction between PrP proteins and GFAP was tested by Pull-down and immunoprecipitation assays. RESULTS: Both native PrP(C) and its protease-resistant isoform (PrP(Sc)) formed complexes with the native GFAP. The full-length recombinant PrP proteins interacted with GFAP. The domain responsible for interacting GFAP was located at C-terminal of PrP (residues 91 to 231). CONCLUSION: The studies of the association of PrP with GFAP may further provide insight into a potential role of GFAP in the biological function of PrP and the pathogenesis of prion disease.