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.

抽象的肿瘤抑制基因TP53是人类癌症中最常见的突变基因。理解 p53功能和调节的全部广度对于我们对肿瘤起始的理解至关重要发展。 MDM2原始抗蛋白蛋白是通过促进p53的主要负调节剂多泛素化和蛋白质体降解。 MDM2同源蛋白MDMX也充当 p53的负调节器。尽管仍然存在许多问题，但专注于体内模型的使用允许要仔细观察此MDM2/MDMX-P53途径的调节，并有了新发现的重点该途径可以更好地操纵治疗成绩。在过去的几年中，我们的实验一直集中在生成和检查MDM2上 MDM2 E3连接酶功能或MDM2-MDMX结合缺乏的突变敲入小鼠。我们有产生的MDM2C462A和MDM2Y487A突变小鼠，都缺乏MDM2 E3连接酶功能。研究 MDM2C462A小鼠也缺乏MDM2-MDMX相互作用，而MDM2Y487A小鼠保留MDM2-- MDMX相互作用，已通过MDM2 E3连接酶和对体内的体内调节产生了新的见解。 MDM2-MDMX异质体。最近，我们生成了许多新的鼠标型号 MDM2和MDMX背景。我们用这些诱导p53小鼠生成的初步数据具有揭示了一些令人惊讶的发现。我们发现MDMX可以独立于抑制p53表达 MDM2 E3连接酶功能；我们发现MDM2介导的p53降解需要体内MDMX。我们发现MDM2C462A突变体已获得刺激p53的新形态功能转录活动。本应用程序中提出的实验旨在研究（1）MDMX是否调节p53 通过调节其翻译来表达；（2）MDMX影响的机制是什么 MDM2介导的p53降解；（3）环手指突变体MDM2如何获得激活p53的函数。这些实验为探索MDM2环E3连接酶的抑制提供了原则证明证据 MDM2-MDMX相互作用的功能和破坏作为针对的潜在药物开发策略表达高水平MDM2和MDMX和WT p53的癌症。