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In vivo regulation of p53 by MDM2 and MDMX

MDM2 和 MDMX 对 p53 的体内调节

基本信息

批准号：
10225456
负责人：
YANPING ZHANG
金额：
$ 37.7万
依托单位：
UNIV OF NORTH CAROLINA CHAPEL HILL
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-08-01 至 2023-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10225456
关键词：
Address Affect Animal Model Apoptosis Binding Cell Cycle Arrest Cell Nucleus Cytoplasm Cytoplasmic Protein DNA Damage Data Development Enzymes Genes Genetic Transcription Genotoxic Stress Goals Growth and Development function Heterodimerization Homologous Gene Homologous Protein Human In Vitro Individual Knock-in Mouse MDM2 gene Malignant Neoplasms Mediating Metabolism Molecular Mus Mutant Strains Mice Mutate Mutation Oncoproteins Pathway interactions Physiological Play Polyubiquitination Public Health Regulation Reproduction Ring Finger Domain Role Signaling Protein Site TP53 gene Technology Testing Therapeutic Transactivation Translations Tumor Suppressor Genes Tumor Suppressor Proteins Ubiquitination Work design drug development experimental study functional genomics in vivo in vivo Model innovation insight mouse model mutant mutant mouse model new therapeutic target novel p53 Signaling Pathway senescence transcription factor tumor initiation ubiquitin-protein ligase

项目摘要

ABSTRACT The tumor suppressor gene TP53 is the most commonly mutated gene in human cancers. Understanding the full breadth of p53 function and regulation is crucial to our understanding of tumor initiation and development. The MDM2 proto-oncoprotein is a primary negative regulator for p53 by promoting p53 polyubiquitination and proteosomal degradation. The MDM2 homologous protein MDMX also functions as a negative regulator for p53. While many questions remain, a focus on the use of in vivo models is allowing for a closer view of how this MDM2/MDMX-p53 pathway is regulated, with a newfound emphasis on how this pathway can be better manipulated for therapeutic gains. During the last few years, our experiments have been focused on generating and examining MDM2 mutation knock-in mice that are deficient in MDM2 E3 ligase function or MDM2-MDMX binding. We have generated MDM2C462A and MDM2Y487A mutant mice, both lacking MDM2 E3 ligase function. Studies with the MDM2C462A mice, which also lack MDM2-MDMX interaction, and the MDM2Y487A mice, which retain MDM2- MDMX interaction, have generated new insight into the in vivo regulation of p53 by MDM2 E3 ligase and the MDM2-MDMX heterooligomer. Recently, we have generated a number of new mouse models expressing an inducible p53 under various MDM2 and MDMX backgrounds. Our preliminary data generated with these inducible p53 mice have revealed several surprising findings. We found that MDMX can suppress p53 expression independent of MDM2 E3 ligase function; we found that in vivo MDMX is required for MDM2 mediated p53 degradation; and we found that the MDM2C462A mutant has gained a neomorphic function for stimulating p53 transcriptional activity. Experiments proposed in this application are designed to study (1) whether MDMX regulates p53 expression through modulating its translation; (2) what is the mechanism by which MDMX impacts on MDM2 mediated p53 degradation; (3) how the RING finger mutant MDM2 gained a function to activate p53. These experiments provide proof-of-principle evidence for exploring inhibition of MDM2 RING E3 ligase function and disruption of MDM2-MDMX interaction as potential drug development strategies targeting cancers expressing high levels of MDM2 and MDMX and WT p53.

摘要肿瘤抑制基因TP 53是人类癌症中最常见的突变基因。理解 p53功能和调节的全宽度对于我们理解肿瘤的发生和发展是至关重要的。发展MDM 2原癌蛋白是p53的主要负调节因子，通过促进p53 多聚泛素化和蛋白酶体降解。MDM 2同源蛋白MDMX也作为一种免疫调节剂发挥作用。 p53的负调节因子。尽管仍存在许多问题，但对体内模型使用的关注使得为了更近距离地了解MDM 2/MDMX-p53通路是如何调节的，新发现的重点是如何可以更好地操纵该途径以获得治疗效果。在过去的几年里，我们的实验一直集中在生成和检查MDM 2 MDM 2 E3连接酶功能或MDM 2-MDMX结合缺陷的突变敲入小鼠。我们有产生了MDM 2C 462 A和MDM 2 Y 487 A突变小鼠，两者都缺乏MDM 2 E3连接酶功能。研究与 MDM 2C 462 A小鼠，其也缺乏MDM 2-MDMX相互作用，和MDM 2 Y 487 A小鼠，其保留MDM 2-MDMX相互作用。 MDMX相互作用，产生了新的见解，在体内调节p53的MDM 2 E3连接酶和蛋白质的相互作用。 MDM 2-MDMX杂寡聚体。最近，我们已经产生了许多新的小鼠模型，在各种条件下表达诱导型p53。 MDM 2和MDMX背景。我们用这些诱导型p53小鼠产生的初步数据表明，揭示了几个惊人的发现我们发现MDMX可以抑制p53的表达，而不依赖于 MDM 2 E3连接酶功能;我们发现，在体内MDMX是MDM 2介导的p53降解所必需的; 我们发现MDM 2C 462 A突变体获得了刺激p53的新变体功能，转录活性本申请中提出的实验被设计为研究（1）MDMX是否调节p53 （2）MDMX通过什么机制影响其表达？ MDM 2介导的p53降解;（3）RING指突变体MDM 2如何获得激活p53的功能。这些实验为探索MDM 2 RING E3连接酶的抑制提供了原理性证据 MDM 2-MDMX相互作用的功能和破坏作为潜在的药物开发策略，表达高水平MDM 2和MDMX以及WT p53的癌症。