Mitochondrial p32 regulation of the Mdm2-p53 tumor suppression signaling and apop

线粒体 p32 对 Mdm2-p53 肿瘤抑制信号和 apop 的调节

• 批准号: 8186498
• 负责人: YANPING ZHANG
• 金额: $ 30.71万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2017-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8186498
• 关键词: Apoptosis; Apoptotic; Binding; Biochemical; Biological Process; Biology; CDKN2A gene; Cell Death; Cells; Cytoplasm; Data; Degenerative Disorder; Development; Disease; Drug Delivery Systems; Event; Future; Genetic; Human; Knockout Mice; Lead; Link; Malignant Neoplasms; Mediator of activation protein; Metabolic; Mitochondria; Mitochondrial Proteins; Molecular; Monitor; Mutation; Nature; Neurodegenerative Disorders; Oncogenic; Outcome; Oxidative Phosphorylation; Pathogenesis; Pathway interactions; Physiological; Process; Regulation; Reporting; Research; Rest; Rheumatoid Arthritis; Role; Signal Transduction; Specific qualifier value; Stimulus; Stress; System; Testing; Therapeutic Intervention; Tumor Suppression; Tumor Suppressor Proteins; base; cancer cell; caspase-9; cellular protein p32; cytochrome c; design; drug development; inhibitor/antagonist; mouse development; mutant; novel; response; stressor; tumorigenesis

DESCRIPTION (provided by applicant): A mitochondria-localized protein, p32, was recently identified by our lab as a binding partner for the tumor suppressor protein p14ARF. Preliminary data indicated that p32 is essential for p14ARF, a critical mediator for transducing hyperproliferative, oncogenic stress signals to the Mdm2-p53 tumor suppression pathway, to localize to mitochondria and to induce p53-dependent apoptosis. Importantly, human cancer-derived p14ARF mutations that disrupt p32 binding can impair both of these functions. Recently, our preliminary studies have shown that p32 is in fact essential for apoptosis induced by a broad range of apoptotic stimuli. The overall hypothesis behind the proposed research is that p32 specifies an essential factor for a surveillance system that monitors the integrity of mitochondrial function and promotes apoptosis in response to irreparable mitochondrial damage. The rationale for the hypothesis is based on the following observations. (1) p32 is a mitochondrial protein. (2) Knockdown p32 desensitizes cells to apoptosis induced by a broad range of apoptotic stimuli. (3) Like cytochrome c, p32 accumulates in the cytoplasm during apoptosis. (4) Ectopically expressed, cytoplasm- localized p32 induces apoptosis. (5) p32 is reported to have a role in oxidative phosphorylation. The experimental focus of the proposal is on dynamics and outcome of p32 localization, function and mechanism of p32 in regulating apoptosis, and genetics and biology of p32 in metabolic regulation and tumorigenesis. Based on these observations, the proposed research will focus on characterizing the function and mechanism of p32 in regulating apoptosis by a combination of biochemical, cellular, and genetic approaches. The specific aims are designed to assess p32's role in regulating apoptosis under a broad range of apoptotic conditions and define the dynamics of p32 subcellular localization, to Investigate mechanisms by which p32 promotes apoptotic cell death, and to investigate p32's physiological function using p32 conditional knockout mice. If successful, the proposed study will ascribe new functions to p32. It will also aid in our understanding of apoptotic cell death - a process that is critical during development and in the pathogenesis of diseases such as cancer, rheumatoid arthritis, and neurodegenerative diseases - and may eventually lead to additional drug targets for controlling apoptosis in treatment of these diseases. PUBLIC HEALTH RELEVANCE: The quest to delineate the apoptosis pathway is highly motivated by the possibility of targeting human cancer or other degenerative diseases through manipulating apoptotic signaling. This proposal is built upon our strong preliminary data identifying the mitochondrial protein p32 to be physically and functionally linked to the p14ARF-Mdm2- p53 tumor suppression pathway. The objective of this proposal is test whether and how p32 signals to p14ARF and p53 and regulates apoptosis. The potential high impact of this proposal rests on the promise of establishing p32 as a novel regulator of apoptotic cell death, the aberrant regulation of which is implicated in the development of many diseases including cancer.

描述（由申请人提供）：我们的实验室最近鉴定出线粒体定位蛋白 p32 作为肿瘤抑制蛋白 p14ARF 的结合伴侣。初步数据表明，p32 对于 p14ARF 至关重要，p14ARF 是将过度增殖、致癌应激信号转导至 Mdm2-p53 肿瘤抑制途径、定位于线粒体并诱导 p53 依赖性细胞凋亡的关键介质。重要的是，破坏 p32 结合的人类癌症衍生的 p14ARF 突变会损害这两种功能。最近，我们的初步研究表明p32实际上对于广泛的细胞凋亡刺激诱导的细胞凋亡至关重要。这项研究背后的总体假设是，p32 指定了监测系统的一个重要因素，该系统监测线粒体功能的完整性并促进细胞凋亡以应对不可修复的线粒体损伤。该假设的基本原理基于以下观察。 (1) p32是一种线粒体蛋白。 (2) Knockdown p32 desensitizes cells to apoptosis induced by a broad range of apoptotic stimuli. (3) 与细胞色素c一样，p32在细胞凋亡过程中在细胞质中积累。 (4) 异位表达、定位于细胞质的 p32 诱导细胞凋亡。 (5) 据报道，p32 在氧化磷酸化中发挥作用。该提案的实验重点是p32定位的动态和结果、p32在调节细胞凋亡中的功能和机制、以及p32在代谢调节和肿瘤发生中的遗传学和生物学。基于这些观察结果，拟议的研究将集中于通过结合生化、细胞和遗传方法来表征 p32 在调节细胞凋亡中的功能和机制。具体目标是评估p32在广泛的细胞凋亡条件下调节细胞凋亡的作用，定义p32亚细胞定位的动态，研究p32促进细胞凋亡的机制，并使用p32条件敲除小鼠研究p32的生理功能。如果成功，拟议的研究将赋予 p32 新功能。它还将有助于我们了解细胞凋亡（这一过程在癌症、类风湿性关节炎和神经退行性疾病等疾病的发育和发病机制中至关重要），并最终可能导致在这些疾病的治疗中控制细胞凋亡的其他药物靶点。 公共健康相关性：通过操纵细胞凋亡信号传导来靶向人类癌症或其他退行性疾病的可能性极大地激发了对细胞凋亡途径的探索。该提议建立在我们强有力的初步数据之上，该数据确定线粒体蛋白 p32 在物理和功能上与 p14ARF-Mdm2-p53 肿瘤抑制途径相关。该提案的目的是测试 p32 是否以及如何向 p14ARF 和 p53 发出信号并调节细胞凋亡。该提案的潜在重大影响取决于将 p32 作为细胞凋亡的新型调节剂的承诺，其异常调节与包括癌症在内的许多疾病的发展有关。