PrP及其缺失突变体与GFAP体外相互作用的初步研究

目的研究PrP蛋白与GFAP蛋白是否发生分子间相互作用以及PrP蛋白多肽链中与GFAP蛋白相互作用的区域。方法制备仓鼠脑组织匀浆上清,通过原核表达系统以及体外翻译系统表达了全长的小鼠GFAP蛋白、人PrP蛋白以及各种缺失突变体,利用Pull-down及免疫共沉淀实验检测PrP与GFAP的分子间相互作用。结果不仅重组的GFAP与PrP发生分子间的相互作用,而且脑组织中的GFAP与PrPC及PrPSc也发生相互作用。PrP与GFAP蛋白相互作用的区域位于PrP的C端第91至231位氨基酸。结论PrP及其缺失突变体与GFAP在体外能够发生分子间的相互作用,提示GFAP可能参与朊蛋白的正常生理功能或者朊病毒病的病理过程。

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 PrPC and its protease-resistant isoform(PrP Sc)formed comlexes 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.