Global Analysis of Human Prion Protein Interactors by Protein Microarray

目的：通过蛋白质芯片研究PrPC相互作用蛋白(PrPIPs)，了解PrPC的功能。方法：我们用编码23-231个氨基酸残基的重组人PrPC序列探测5,000个人类蛋白质，鉴定了47个新的PrPIP，命名为PR209。结果：在47个PrPIP中，绝大多数被注释为参与核酸识别的蛋白质。免疫共沉淀和瞬时表达系统中的细胞成像证实了PR209与神经元PrPIP如FAM64A、HOXA1、PLK3和MPG的相互作用。然而，这种相互作用并没有产生抗蛋白酶K的蛋白。生物信息学工具KeyMolnet显示PrPC和PrPIPs的复杂分子网络与AKT、JNK和MAPK信号通路密切相关。结论：蛋白质芯片是一种有用的工具，可用于系统筛选和全面分析人类PrPC相互作用组。由于PrPC及其相互作用分子网络涉及对细胞生存、分化、增殖和凋亡的调控至关重要的信号通路，这些观察结果提出了一个逻辑假说，即PrPC相互作用组的调节失调可能会导致PrPC相互作用组疾病的广泛神经变性。

Aims : To obtain an insight into the function of cellular prion protein(PrPC), we studied PrPC-interacting proteins(PrPIPs) by analyzing a protein microarray. Methods : We idenitified 47 novel PrPIPs by probing the array of 5,000 human proteins with recombinant human PrPC spanning amino acid residues 23-231 named PR209. Results : The great majority of 47 PrPIPs were annotated as the proteins involved in the recognition of nucleic acids. Coimmunoprecipitation and cell imaging in a transient expression system validated the interaction of PR209 with neuronal PrPIPs, such as FAM64A, HOXA1, PLK3 and MPG. However, the interaction did not generate proteinase K-resistant proteins. KeyMolnet, a bioinformatics tool for analyzing molecular interaction on the curated knowledge database, revealed that the complex molecular network of PrPC and PrPIPs has the significant relationship with AKT, JNK and MAPK signaling pathways. Conclusions : Protein microarray is a useful, tool for systematic screening and comprehensive profiling of the human PrPC interactome. Because the network of PrPC and interactors involves signaling pathways essential for regulation of cell survival, differentiation, proliferation and apoptosis, these observations propose a logical hypothesis that dysregulation of the PrPC interactome might induce extensive neurodegeneration in prion diseases.