Function and regulation of MDMX intra-molecular interactions

MDMX分子内相互作用的功能和调节

基本信息

批准号：
9094690
负责人：
JIANDONG CHEN
金额：
$ 39.35万
依托单位：
H. LEE MOFFITT CANCER CTR & RES INST
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-08-01 至 2020-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9094690
关键词：
Binding Biochemical Biological Assay CSNK1A1 gene Cells Clinical Trials Clustered Regularly Interspaced Short Palindromic Repeats DNA Binding DNA Damage Detection Generations Genes Health Homologous Gene Human Knowledge Lead MDM2 gene Malignant Neoplasms Mediating Mediator of activation protein Molecular Mus Mutate Nuclear Translocation Pathway interactions Phosphorylation Physiological Protein p53 Proteins Regulation Resistance Role Signal Pathway Signal Transduction Stress Structure TP53 gene Testing Treatment Efficacy Tumor Suppression Tumor Suppressor Proteins Work biological adaptation to stress cancer therapy functional status inhibitor/antagonist mimetics mimicry mouse model new therapeutic target novel novel strategies novel therapeutics overexpression research study resistance mechanism response senescence small molecular inhibitor tool tumor ubiquitin-protein ligase

项目摘要

DESCRIPTION (provided by applicant): MDM2 and its homolog MDMX are important regulators of the p53 tumor suppressor. MDMX overexpression occurs in a subset of human tumors and is an alternative mechanism for inactivating p53. MDMX is resistant to MDM2 inhibitors such as Nutlin, therefore MDMX overexpression may reduce the efficacy of MDM2 inhibitors currently entering clinical trials. Understanding the structure and regulation of MDMX will be critical for the successful targeting of p53 pathway in cancer therapy. MDMX does not have E3 ligase activity and its mechanism of p53 regulation is poorly understood. We showed that MDMX is an important target of signaling pathways that activate p53. DNA damage induces MDMX phosphorylation by ATM/Chk2, promotes MDMX nuclear translocation and degradation, and inhibits MDMX binding to CK1 and p53. To elucidate the mechanism of MDMX regulation and signal integration, we established a novel assay for the detection of protein intra-molecular interactions. We demonstrate that different MDMX domains engage in intra-molecular binding, which results in auto inhibition by p53 mimicry. We hypothesize that the intra-molecular interactions in MDMX are important for its function and regulation. The following experiments are proposed to further study the MDMX internal interactions during stress response. (1) Investigate the regulation of MDMX internal interactions using a novel proteolytic fragment release assay. (2) Determine the mechanism of p53 inhibition by MDMX and CK1. (3) Investigate the mechanism of senescence stimulation by MDMX. (4) Determine the physiological functions of MDMX internal interactions using mouse model. These experiments should lead to a better understanding of the mechanisms that regulate MDMX and may identify novel strategy for targeting MDMX in human cancer.

描述（由申请人提供）：MDM2 及其同源物 MDMX 是 p53 肿瘤抑制因子的重要调节因子，MDMX 过度表达发生在人类肿瘤的亚型中，并且是灭活 p53 的另一种机制，因此 MDMX 对 MDM2 抑制剂（例如 Nutlin）具有抗性。 MDMX 过度表达可能会降低目前进入临床试验的 MDM2 抑制剂的功效，了解 MDMX 的结构和调节对于成功靶向癌症中的 p53 通路至关重要。 MDMX 不具有 E3 连接酶活性，其 p53 调节机制知之甚少。，并抑制 MDMX 与 CK1α 和 p53 的结合为了阐明 MDMX 调节和信号整合的机制，我们建立了一种检测分子内蛋白质的新方法。我们证明不同的 MDMX 结构域参与分子内结合，从而导致 p53 拟态的自动抑制。我们发现 MDMX 中的分子内相互作用对其功能和调节很重要。 (1) 使用新型蛋白水解片段释放测定研究 MDMX 内部相互作用的调节。 (2) 确定 MDMX 和 CK1 抑制 p53 的机制。 (3) 研究 MDMX 刺激衰老的机制。 (4) 使用小鼠模型确定 MDMX 内部相互作用的生理功能。这些实验应该有助于更好地理解 MDMX 的调节机制，并可能确定针对 MDMX 的新策略。人类癌症。