Protein quality control in age-related diseases

摘要 蛋白质质量控制对于细胞功能至关重要，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，与蛋白质质量控制改变有关，强调了重要性 健康和疾病中的蛋白质保真度。 CHIP（热休克 70 相互作用蛋白的羧基末端）是一种多 具有独特活性的功能酶，有助于蛋白质折叠和蛋白质降解。我们实验室最近 确定了第一种与 CHIP 突变相关的人类疾病，其表型包括加速衰老， 小脑共济失调和变性、认知功能障碍和性腺功能减退。两种已知的 CHIP 底物，受体- 相互作用蛋白激酶 3 (RIPK3) 和 AMP 激活激酶 (AMPK) 受降解或重新调节 CHIP 的折叠活动。这些激酶调节重要的细胞过程，坏死性凋亡（一种炎症 形式的程序性细胞死亡）和细胞代谢，两者都是细胞对细胞反应能力的核心 随着衰老或病理生理条件而发生的压力。在本提案中，我们试图定义蛋白质的作用 通过确定 CHIP 的各种活动如何调节最近发现的这些活动来控制老化 底物，以及当 CHIP 功能受损时驱动细胞应激敏感性的机制。我们的 该方法包括加速衰老的新型临床前模型、尖端细胞模型以及确定分子 CHIP 与其基板接合时的运动。然后我们询问 CHIP 中的致病突变如何 机械地驱动与 CHIP 功能障碍相关的分子和细胞表型。最后，我们将使用我们的 临床前模型以确定当坏死性凋亡受到抑制时衰老和疾病病理如何改变 药理学上，或者当 CHIP 功能通过基因恢复时。这些研究的最终目标是确定 CHIP调节的信号通路的药物靶点影响年龄依赖性退行性病变的进展 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.