Regulatory Mechanisms Governing BubR1 Protein Stability During Stress and Aging

压力和衰老过程中 BubR1 蛋白稳定性的调控机制

• 批准号: 10624953
• 负责人: Brian J. North
• 金额: $ 29.83万
• 依托单位: CREIGHTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2027-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10624953
• 关键词: Acceleration; Acetylation; Acetyltransferase; Age; Aging; Aneuploidy; Animals; Binding; Biological; CHEK1 gene; CREBBP gene; Cell Aging; Cell Survival; Cell physiology; Cellular Stress; Cullin Proteins; Cyclin D1; Deacetylase; Disease; Ensure; F Box Domain; Fibroblasts; Genetic; Genome Stability; Genomic Instability; Glucose; Goals; Health; Human; In Vitro; Link; Longevity; Lysine; Malignant Neoplasms; Mammals; Mediating; Mitosis; Mitotic; Molecular; Mus; Mutation; Nutrient; Pathology; Pathway interactions; Physiological; Post-Translational Regulation; Premature aging syndrome; Process; Protein Acetylation; Proteins; Proteome; Proteomics; Regulation; Role; Signal Pathway; Signal Transduction; Signaling Protein; Stress; Testing; Therapeutic; Tissues; Tumor Suppressor Proteins; Ubiquitin; Ubiquitination; age related; aged; deprivation; detection of nutrient; druggable target; genome integrity; healthspan; in vivo Model; mouse model; neoplastic cell; novel therapeutic intervention; nutrient deprivation; prevent; protein degradation; response; segregation; senescence; tumor progression; tumorigenesis; ubiquitin-protein ligase

Abstract: BubR1 is a key regulator of aging through suppressing cellular senescence and is a critical tumor suppressor through its role in maintaining genome integrity by sustaining fidelity in chromosomal segregation during mitosis through control of the spindle assembly checkpoint. Importantly, BubR1 levels decline with age putting it at the intersection of aging and age-related diseases such as cancer. Loss of BubR1 with age is attributed, in part, through its increased ubiquitin-proteasomal mediated degradation, which can be blocked by increasing the activity of the NAD+-dependent deacetylase SIRT2. However, the E3 ubiquitin ligase(s) involved in promoting the decline in BubR1 with age and under conditions of stress remain elusive. We identified the Skp1-Cullin-F-box (SCF) E3 ubiquitin ligase substrate recognition subunit -TRCP1 as an interactor of BubR1, which targets BubR1 for ubiquitination and degradation. BubR1 contains a putative binding domain for -TRCP1 (known as a degron motif), which lies adjacent to the acetylated lysine controlled by SIRT2 suggesting a cross talk between SIRT2-regulated acetylation and ubiquitination of BubR1 by - TRCP1. Furthermore, -TRCP1 is involved in ubiquitination and degradation of key regulators of genome stability and cancer such as CHK1 and Cyclin D1 in response to cellular stress, including nutrient deprivation. Similarly, BubR1 protein levels are destabilized in response to glucose deprivation, suggesting a putative role for -TRCP1 in regulating BubR1 under physiological stress conditions as well as during the natural aging process. Based on these observations, we hypothesize that -TRCP1 is a key regulator of BubR1 protein stability to control aging and disease. To test this hypothesis, we developed two specific aims. In aim 1 we will define the posttranslational regulation of BubR1 by -TRCP1 at the molecular level, and its impact on cellular senescence and organismal lifespan. These studies will investigate the upstream and downstream pathways by which -TRCP regulates BubR1 protein stability, and its involvement in the promoting the decline of BubR1 with age. In aim 2 we will determine the role of -TRCP1-mediated protein degradation of BubR1 under conditions of cellular stress including glucose deprivation by delineating the molecular mechanisms linking cellular sensing of nutrient stress to ubiquitin-proteasomal mediated degradation of BubR1. In addition, we will assess the consequences of altering BubR1 and other regulators of genome stability in the cellular response to glucose restrictive conditions. Finally, we will elucidate the role of -TRCP1 in proteome remodeling during the cellular response to glucose restriction conditions using an unbiased proteomics-based interaction screen. The overall goal of this proposal is to elucidate at the molecular and cellular level the role of -TRCP in controlling key regulators of genomic stability including BubR1 during cellular stress in aging and disease, which will provide the impetus to develop novel therapeutic interventions for aging and age-related diseases through stabilization of BubR1.

摘要： BubR 1是通过抑制细胞衰老的关键调节因子，并且是关键的肿瘤抑制因子 通过其在维持染色体分离中的保真度来维持基因组完整性的作用， 通过控制纺锤体组装检查点来控制有丝分裂。重要的是，BubR 1水平随着年龄的增长而下降 它处于衰老和与年龄有关的疾病（如癌症）的交叉点。BubR 1随着年龄的增长而丢失， 部分，通过其增加的泛素-蛋白酶体介导的降解，这可以通过增加 NAD+依赖性脱乙酰酶SIRT 2的活性。然而，E3泛素连接酶参与了 促进BubR 1随年龄和在压力条件下的下降仍然难以捉摸。 我们鉴定了Skp 1-Cullin-F-box（SCF）E3泛素连接酶底物识别亚基-TRCP 1 作为BubR 1的相互作用物，其靶向BubR 1进行泛素化和降解。BubR 1含有一个假定的 与乙酰化赖氨酸控制的结合结构域（称为降解决定子基序）相邻 通过SIRT 2表明SIRT 2调节的乙酰化和BubR 1的泛素化之间的串扰， TRCP 1。此外，TRCP 1还参与基因组关键调控因子的泛素化和降解 稳定性和癌症，如CHK 1和细胞周期蛋白D1响应细胞应激，包括营养缺乏。 类似地，BubR 1蛋白水平在葡萄糖剥夺反应中不稳定，这表明BubR 1蛋白在葡萄糖缺乏反应中可能起作用。 在生理应激条件下以及在自然衰老过程中， 过程基于这些观察结果，我们假设BubR 1蛋白的一个关键调节因子是TRCP 1， 控制衰老和疾病的稳定性。 为了验证这一假设，我们制定了两个具体目标。在目标1中，我们将定义翻译后 BubR 1在分子水平上的调节，及其对细胞衰老和生物体的影响 寿命这些研究将调查的上游和下游途径，通过该途径， BubR 1蛋白的稳定性，及其参与促进BubR 1随年龄的下降。在目标2中， 确定在细胞应激条件下BubR 1的Bub-TRCP 1介导的蛋白质降解的作用 包括葡萄糖剥夺，通过描绘连接细胞对营养物质的感知的分子机制， 应激对泛素-蛋白酶体介导BubR 1降解的影响。另外，我们会评估 改变BubR 1和其他基因组稳定性调节因子， 条件最后，我们将阐明在细胞反应过程中的蛋白质组重塑中的作用， 葡萄糖限制条件使用一个公正的蛋白质组学为基础的相互作用屏幕。的总目标 本研究拟在分子和细胞水平上阐明β-TRCP在控制关键调控因子中的作用 包括BubR 1在内的基因组稳定性在衰老和疾病的细胞应激期间，这将提供动力 通过稳定BubR 1来开发针对衰老和年龄相关疾病的新型治疗干预措施。