Bacterial Cell-Based Assays for Prion Proteins

描述（由申请人提供）：朊病毒是自我维持的蛋白质聚集体，其首先在哺乳动物中被认识到在一组称为传染性海绵状脑病（TSE）的灾难性和不可治愈的神经退行性疾病中的作用。朊病毒样现象在酵母中的发现为朊病毒生物学的研究提供了一个强有力的模型系统。而不是杀死细胞，酵母朊病毒可以赋予细胞新的表型性状，繁殖表观遗传。到目前为止，还没有发现细菌朊病毒。然而，这可能只是反映了在不允许检测细胞质遗传的生物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。 拟议研究的目的是开发一种基于转录的检测方法，用于将蛋白质结构域转化为朊病毒状态，并使用这种检测方法作为遗传筛选的基础，以确定来自细菌和其他生物体的朊病毒形成结构域。本试验的设计将参考实验室先前开发的其他基于转录的试验。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朊病毒蛋白的体内行为，无论是细菌来源还是真核细胞。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提供与理解哺乳动物朊病毒疾病相关的见解。

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.