Analysis of force developed by a AAA ATPase

描述（由申请人提供）：AAA atp酶家族包括的分子，其作用包括但不仅限于线粒体和多泡体的生物发生，参与基因调控和蛋白质运输的蛋白质。本项目将重点研究这些机器在单分子水平上的活性。模型蛋白将是ClpX——它是蛋白质小体的一部分，是蛋白质降解的关键作用，它将蛋白质展开，为降解做准备。细胞蛋白质的半衰期各不相同，从几分钟到几天不等。通过允许细胞蛋白水平的快速变化，调节降解有助于控制信号转导途径、细胞周期、转录、凋亡、抗原加工、生物钟控制、分化和表面受体脱敏。需要解决的问题是：在不同的结果之间，工作是如何分配的？系统能做的最大功是多少？什么因素限制了它的工作效率？这些问题具有健康意义：人类病理状况与降解系统的失效有关，其调节提供了治疗干预的潜力。此外，蛋白酶体催化活性抑制剂被用于治疗复发性多发性骨髓瘤，蛋白酶体抑制剂正在临床试验中用于治疗广泛的人类恶性肿瘤。因此，了解蛋白质半衰期的调节应该为细胞生理学和病理学提供关键的见解。在整个生物学中，对异常蛋白质的处理不当会招致惩罚：细菌在压力下的生存取决于处理错误折叠和结构异常蛋白质的系统的有效表现——要么正确折叠它们，要么摧毁它们。需要解决的具体问题是：设备拉动的力度有多大才能展开？需要多少次拉动才能不可逆地提交？拉力的极限是什么，拉力的统计分布是什么？这些问题的答案不仅将开始揭示这些机器做什么，还将揭示决策树，该决策树描述了如何控制结果以及何时可能超出机器的能力。我们不仅想知道机器是如何工作的，还想知道它的决策树如何产生不同的结果。

DESCRIPTION (provided by applicant): The AAA ATPases family includes molecules whose roles include, but are far from limited to, biogenesis of mitochondria and multivesicular bodies, proteins in involved in gene regulation and protein transport. This project will focus on studying the activity of these machines at the single molecule level. The model protein will be ClpX - it is the part of the proteosome, a key effect of protein degradation that unfolds the proteins to prepare them for degradation. . Cellular proteins differ widely in their liability, from half-lives of minutes to days. Regulated degradation, by allowing rapid changes in the levels of cellular proteins, helps control signal transduction pathways, the cell- cycle, transcription, apoptosis, antigen processing, biological clock control, differentiation and surface receptor desensitization. The questions to be addressed are: How is work partitioned between alternative outcomes? What is the maximum work that can be performed by the system? What factors limit its efficiency in performing work? These questions have health implications: human pathological conditions are associated with failures of the degradation system and its regulation offers the potential for therapeutic intervention. Furthermore, an inhibitor of proteasome catalytic activity is in use for treatment of recurrent multiple myeloma, and proteasome inhibitors are in clinical trial for treatment of a broad spectrum of human malignancies. Thus, understanding the regulation of the half-life of proteins should provide critical insights into cell physiology and pathology. The mishandling of aberrant proteins incurs penalties throughout biology: the survival of bacteria subjected to stress depends on the effective performance of systems which deal with misfolded and structurally aberrant proteins- to either fold them properly or destroy them. The specific questions to be addressed are: How hard can the device pull to cause unfolding? How many pulls are needed to commit irreversibly? What is the limit of pulling power, and the statistical distribution of pulling power? Answers to these questions will begin to reveal not just what these machines do but the decision tree that describes how outcomes are controlled and when machine capacity may be exceeded. We want to know not just how the machine works, but how its decision tree yields alternative outcomes. PUBLIC HEALTH RELEVANCE: The AAA ATPases family includes molecules whose roles include, but are far from limited to, biogenesis of mitochondria and multivesicular bodies, proteins in involved in gene regulation and protein transport. The model will be a protein involved in degrading other proteins. Human pathological conditions are associated with failures of the degradation system and its regulation offers the potential for therapeutic intervention. Furthermore, an inhibitor of proteasome catalytic activity is in use for treatment of recurrent multiple myeloma, and proteasome inhibitors are in clinical trial for treatment of a broad spectrum of human malignancies.