Bacterial Cell-Based Assays for Prion Proteins

描述(申请人提供)：Prion是一种自我永久化的蛋白质聚集体，最初在哺乳动物中被认为是在一组灾难性的和不可治愈的神经退行性疾病中所起的作用，称为传染性海绵状脑病(TSE)。在酵母中发现类普里子现象，为普恩生物学的研究提供了一个强有力的模型系统。酵母蛋白不是杀死细胞，而是赋予细胞新的表型特征，这些表型特征是通过表观遗传繁殖的。到目前为止，还没有发现细菌普恩病毒。然而，这可能只是反映了在不允许检测细胞质遗传的有机体中识别基于蛋白质的遗传元件的困难；在细菌中，交配不涉及细胞质的转移。 这项拟议的研究的目的是开发一种基于转录的分析方法，将蛋白质结构域转换为普恩状态，并将这种测试作为遗传筛选的基础，以识别细菌和其他生物中的普恩形成结构域。这项检测的设计将参考实验室以前开发的其他基于转录的检测方法。这项拟议工作的长期目标是动员细菌遗传学作为一种新的工具来研究Pron蛋白的体内行为，无论是细菌起源的还是来自真核细胞的。最终，在酵母和细菌中使用遗传上易于处理的模型系统应该会提供与理解哺乳动物基于Pron的疾病相关的见解。

DESCRIPTION (provided by applicant): Prions are self-perpetuating protein aggregates that were first recognized in mammals for their role in a group of catastrophic and incurable neurodegenerative diseases known as the transmissible spongiform encephalopathies (TSEs). The discovery of a prion-like phenomenon in yeast has provided a powerful model system for the study of prion biology. Rather than killing the cell, yeast prions can confer on the cell new phenotypic traits that are propagated epigenetically. To date, no bacterial prions have been identified. However, this may simply reflect the difficulty of recognizing protein-based genetic elements in an organism that does not permit the detection of cytoplasmic inheritance; in bacteria, mating does not involve the transfer of cytoplasm. The objective of the proposed research is to develop a transcription-based assay for the conversion of protein domains to the prion state and to use such an assay as the basis for a genetic screen to identify prion-forming domains from bacteria and other organisms. The design of this assay will be informed by other transcription-based assays previously developed in the laboratory. The long-term goal of the proposed work is to mobilize bacterial genetics as a new tool to study the in vivo behavior of prion proteins, whether of bacterial origin or from eukaryotic cells. Ultimately, the use of genetically tractable model systems in both yeast and bacteria should provide insights that will be relevant to the understanding of the mammalian prion-based diseases.