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.

抽象的： BUBR1是通过抑制细胞感应的关键调节剂，是关键的肿瘤抑制剂 通过其在维持基因组完整性中的作用，通过维持在染色体隔离中的保真度 通过控制主轴组件检查点有丝分裂。重要的是，BUBR1水平随着年龄的增长而下降 它在衰老和与年龄有关的疾病（例如癌症）的交集中。随着年龄的年龄而失去bubr1的损失，在 一部分，通过增加的泛素 - 蛋白酶体介导的降解，可以通过增加来阻止 NAD+依赖性脱乙酰基酶SIRT2的活性。但是，涉及的E3泛素连接酶 随着年龄的增长和压力条件，促进BUBR1的下降仍然难以捉摸。 我们确定了SKP1-cullin-f-box（SCF）E3泛素连接酶底物识别亚基-TRCP1 作为BubR1的相互作用者，它针对BubR1用于泛素化和降解。 BUBR1包含一个推定的 -trcp1的结合结构域（称为degron基序），该结构域与乙酰化赖氨酸控制的相邻 通过SIRT2提示SIRT2调节的乙酰化和BUBR1泛素化之间的串扰。 TRCP1。此外，-trcp1参与了基因组关键调节剂的泛素化和降解 稳定性和癌症（例如CHK1和Cyclin D1）响应细胞应激，包括营养剥夺。 同样，BUBR1蛋白水平对葡萄糖剥夺的响应不稳定，表明推定作用 在身体应力条件下以及自然衰老期间，在调节性BUBR1中的-trcp1 过程。基于这些观察结果，我们假设-trcp1是BUBR1蛋白的关键调节剂 控制衰老和疾病的稳定性。 为了检验这一假设，我们开发了两个具体目标。在AIM 1中，我们将定义翻译后 通过分子水平的-trcp1对BUBR1的调节及其对细胞感应和有机体的影响 寿命。这些研究将研究上游和下游途径，-trcp调节了这些途径 BUBR1蛋白稳定性及其参与随着年龄的增长而促进BUBR1的下降。在目标2中，我们将 确定在细胞应激条件下BUBR1的-trcp1介导的蛋白质降解的作用 通过描述连接养分细胞传感器的分子机制，包括葡萄糖剥夺 泛素 - 蛋白酶体介导的BUBR1降解的压力。此外，我们将评估后果 在细胞对葡萄糖限制的细胞反应中改变BUBR1和其他基因组稳定性调节剂 状况。最后，我们将阐明-trcp1在蛋白质组重塑过程中的作用 使用公正的基于蛋白质组学的相互作用屏幕来葡萄糖限制条件。总体目标 该建议是在分子和细胞水平上阐明-trcp在控制关键调节剂中的作用 衰老和疾病中细胞应激期间包括BUBR1在内的基因组稳定性，这将提供动力 通过稳定BUBR1，开发新的热干预措施，以用于衰老和年龄相关疾病。