Protein quality control in age-related diseases

摘要 蛋白质质量控制对细胞功能至关重要，包括帮助蛋白质折叠和维持结构的途径 构象，以及最终降解蛋白质的细胞系统。几种退行性疾病，包括 伴随着异常衰老的蛋白质，与蛋白质质量控制的改变有关，突显了重要性 蛋白质在健康和疾病中的保真度。CHIP(热休克70-相互作用蛋白的羧基末端)是一种多聚体。 具有不同活性的功能性酶，对蛋白质折叠和蛋白质降解都有贡献。我们的实验室最近 发现了第一种与芯片突变有关的人类疾病，其表型包括加速衰老， 小脑性共济失调和变性，认知功能障碍，性腺功能减退。两种已知的芯片底物，受体- 相互作用蛋白激酶3(RIPK3)和AMP激活的激酶(AMPK)受降解性或再降解性蛋白激酶的调节。 分别研究了芯片的折叠行为。这些激酶调节重要的细胞过程，坏死性下垂(一种炎症性疾病 细胞程序性死亡的形式)和细胞新陈代谢，这两者都是细胞对 随着年龄的增长或在病理生理条件下产生的压力。在这个提案中，我们试图定义蛋白质的作用 通过确定芯片的各种活动如何调节最近发现的这些来控制衰老中的质量 基板，以及当芯片功能受损时驱动对单元应力敏感的机制。我们的 方法包括加速衰老的新的临床前模型，尖端细胞模型，以及确定分子 切屑与其衬底啮合时的运动。然后我们问，芯片中的致病突变是如何 机械驱动与芯片功能障碍相关的分子和细胞表型。最后，我们将使用我们的 临床前模型确定当坏死性下垂被抑制时衰老和疾病病理如何改变 从药理上讲，或者当芯片功能从基因上恢复的时候。这些研究的最终目标是确定 影响退行性变年龄相关性进展的芯片调控信号通路的可药物靶点 条件。

ABSTRACT Protein quality control is vital for cellular function, encompassing pathways that help proteins fold and maintain structural conformations, as well as cellular systems that ultimately degrade proteins. Several degenerative diseases, including those that are accompanied by abnormal aging, are associated with altered protein quality control, highlighting the importance of protein fidelity in both health and disease. CHIP (carboxyl terminus of heat shock 70-interacting protein) is a multi- functional enzyme with distinct activities that contribute both to protein folding and protein degradation. Our lab recently identified the first human disease associated with CHIP mutations, with phenotypes that include accelerated aging, cerebellar ataxia and degeneration, cognitive dysfunction, and hypogonadism. Two known CHIP substrates, receptor- interacting protein kinase 3 (RIPK3) and AMP-activated kinase (AMPK), are regulated by either the degradative or re- folding activities of CHIP, respectively. These kinases regulate important cellular processes, necroptosis (an inflammatory form of programmed cell death) and cellular metabolism, both of which are central to the ability of cells to react to the stress that occurs with aging or in pathophysiological conditions. In this proposal, we seek to define the role of protein quality control in aging by determining how the various activities of CHIP regulate these recently identified substrates, and the mechanism that drives the sensitivity to cell stress when CHIP function is compromised. Our approach includes novel pre-clinical models of accelerated aging, cutting-edge cell models, and determining the molecular movements of CHIP when engaged with its substrate. We then ask how disease-causing mutations in CHIP mechanistically drive the molecular and cellular phenotypes associated with CHIP dysfunction. Finally, we will use our preclinical models to determine how aging and disease pathologies are altered when necroptosis is inhibited pharmacologically, or when CHIP function is restored genetically. The ultimate goal of these studies is to identify druggable targets of CHIP-regulated signaling pathways that impact age-dependent progression of degenerative conditions.