Biological Amyloid Aggregation as a Post-Translational Regulatory Pathway

在正常环境下，生物分子执行维持人体细胞所必需的基本任务。然而，暴露在恶劣和紧张的条件下，如高温、酸性和紫外线辐射，会破坏这些生物分子的功能，损害细胞成分。这需要激活修复途径，试图补偿环境压力源的有害影响。这些细胞对策的成功或失败最终决定细胞和/或生物体是否能在暴露中存活下来。最近，我们发现了一种新的生物途径，可以提高细胞应激期间的存活率。通过致密、不溶性和纤维状蛋白团块（称为淀粉样蛋白）的可逆形成，细胞可以迅速关闭非必需功能，专注于修复受损成分。这些生物淀粉样蛋白特别引人注目的是，它们与神经系统疾病（如阿尔茨海默氏症、帕金森氏症和疯牛病）患者身上发现的有毒斑块非常相似。这表明，这种自然途径可能是疾病相关斑块的生物对应物的第一个例子之一。这项研究计划的目标是加强我们对这一新发现的生物现象的理解。天然淀粉样蛋白聚集体是如何形成和分解的，什么环境压力因素激活了这一过程，以及为什么它对细胞有保护作用，这些都是我们希望解决的长期问题。具体而言，未来5年，我们将着力实现以下三个目标：

Under normal environmental situations, biological molecules perform the basic tasks necessary to maintain human cells. However, exposure to harsh and stressful conditions, such as high temperature, acidity, and UV radiation, can disrupt the function of these biological molecules and damage cellular components. This requires the activation of repair pathways, which attempt to compensate for the harmful effects of an environmental stressor. The success or failure of these cellular countermeasures ultimately determines whether a cell and/or organism survives exposure. Recently, we identified a new biological pathway that enhances survival during periods of cellular stress. Through the reversible formation of dense, insoluble, and fibrous protein clumps (termed amyloids) a cell can rapidly shut down non-essential functions, to focus on repairing the damaged components. What is particularly striking about these biological amyloids is their close resemblance to the toxic plaques found in patients with neurological disorders (such as Alzheimer's, Parkinson's and mad cow diseases). This suggests that this natural pathway may be one of the first examples of a biological counterpart to the disease-associated plaques. The goal of this research program is to enhance our understanding of this newly discovered biological phenomenon. How natural amyloid aggregates form and disassemble, what environmental stressors activate this process, and why it is protective to the cell are long-term questions that we hope to address. Specifically in the next 5 years, we will focus our efforts on the following three aims. Aim I: Examine the essential role of a poorly understood family of biological molecules (noncoding RNA) in the formation of protein clumps. Here, we will identify how environmental signals activate these noncoding RNAs and how these active molecules convert proteins into amyloid aggregates. Aim II: Find new environmental stressors that trigger amyloid formation. This will help us understand how often cells/organisms utilize this novel stress-response pathway. Aim III: Identify the proteins that form stress-specific amyloid aggregates. This is an important question, as it helps us understand how cells adapt to different situations (i.e., high temperature versus low pH), and the results will give us a better understanding of cellular pathways that enhance survival. Overall, this work will be important to basic scientific communities (RNA, structural, and cellular biology), as well as translational researchers who could use our insight into the natural formation of amyloids to generate new therapeutic avenues that could help treat neurological diseases affecting Canada's aging population.