Department Biochemistry of Neurodegenerative Diseases, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Germany.
Max Planck Institute of Molecular Physiology, Dortmund, Germany.
PLoS One. 2018 May 23;13(5):e0197659. doi: 10.1371/journal.pone.0197659. eCollection 2018.
The cellular prion protein (PrPC) is implicated in neuroprotective signaling and neurotoxic pathways in both prion diseases and Alzheimer's disease (AD). Specifically, the intrinsically disordered N-terminal domain (N-PrP) has been shown to interact with neurotoxic ligands, such as Aβ and Scrapie prion protein (PrPSc), and to be crucial for the neuroprotective activity of PrPC. To gain further insight into cellular pathways tied to PrP, we analyzed the brain interactome of N-PrP. As a novel approach employing recombinantly expressed PrP and intein-mediated protein ligation, we used N-PrP covalently coupled to beads as a bait for affinity purification. N-PrP beads were incubated with human AD or control brain lysates. N-PrP binding partners were then identified by electrospray ionization tandem mass spectrometry (nano ESI-MS/MS). In addition to newly identified proteins we found many previously described PrP interactors, indicating a crucial role of the intrinsically disordered part of PrP in mediating protein interactions. Moreover, some interactors were found only in either non-AD or AD brain, suggesting aberrant PrPC interactions in the pathogenesis of AD.
细胞朊病毒蛋白（PrPC）参与朊病毒病和阿尔茨海默病（AD）中的神经保护信号和神经毒性途径。具体来说，天然无序的 N 端结构域（N-PrP）已被证明与神经毒性配体（如 Aβ和瘙痒性朊病毒蛋白（PrPSc）相互作用，并且对于 PrPC 的神经保护活性至关重要。为了更深入地了解与 PrP 相关的细胞途径，我们分析了 N-PrP 的大脑互作组。作为一种采用重组表达的 PrP 和内含肽介导的蛋白质连接的新方法，我们使用共价连接到珠子上的 N-PrP 作为亲和纯化的诱饵。然后，将 N-PrP 珠与人类 AD 或对照脑裂解物孵育。然后通过电喷雾串联质谱（nano ESI-MS/MS）鉴定 N-PrP 结合伴侣。除了新鉴定的蛋白质外，我们还发现了许多先前描述的 PrP 相互作用物，这表明 PrP 的天然无序部分在介导蛋白质相互作用中起着至关重要的作用。此外，一些相互作用物仅在非 AD 或 AD 脑中发现，表明 AD 发病机制中存在异常的 PrPC 相互作用。
