DeSUMOylation regulation of c-Myc

c-Myc 的去SUMO化调节

基本信息

批准号：
10058588
负责人：
Mu-Shui Dai
金额：
$ 37.97万
依托单位：
OREGON HEALTH & SCIENCE UNIVERSITY
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：
2015-04-01 至 2025-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10058588
关键词：
3-Dimensional Affect Binding Biochemical Biology Breast Breast Cancer Model Cancer Biology Cancer cell line Cell Cycle Progression Cell Nucleus Cell Proliferation Cells Complex Consensus Deubiquitinating Enzyme Deubiquitination Enzymes Family member Gene Expression Regulation Genes Goals Growth Hand Homeostasis Human In Vitro Lead Libraries Life Cycle Stages Light Link Malignant Neoplasms Mammary Tumorigenesis Mediating Modification Molecular Mus Normal Cell Nuclear Pore Oncogenic Oncoproteins Pathway interactions Patients Peptide Hydrolases Phosphorylation Play Post-Translational Protein Processing Process Proteins Proteolysis Proto-Oncogene Proteins c-myc Regulation Role Signal Transduction Site System Testing Therapeutic Threonine Tissues Transactivation Transcriptional Regulation Ubiquitin Ubiquitination c-myc Genes cancer therapy cell growth enzyme activity in vivo inhibitor/antagonist insight knock-down malignant breast neoplasm mouse model multicatalytic endopeptidase complex mutant novel novel therapeutics overexpression programs promoter response screening small molecule therapeutic target therapy resistant tumorigenesis ubiquitin ligase ubiquitin-specific protease virtual

项目摘要

Project Summary While properly regulated levels of c-Myc are essential for normal cell growth and proliferation, aberrant overexpression and activation of c-Myc contribute to most human cancers. Thus, c-Myc level and activity must be tightly regulated during normal cell homeostasis. The rapid turnover of c-Myc is controlled by ubiquitin- dependent proteolysis. c-Myc can be ubiquitinated by the Threonine 58 phosphorylation-dependent ubiquitin ligase (E3) complex SCFFbw7 as well as various other ubiquitin E3s. Conversely, c-Myc ubiquitination can be reversed by the action of deubiquitinating enzymes (DUBs), including USP28, USP36 and USP37. Interestingly, c-Myc can also be modified by small ubiquitin-like modifiers (SUMOs). Yet the function of c-Myc SUMOylation is still unclear and how c-Myc is affected by deSUMOylation is unknown. We recently identified the SUMO protease SENP1 as a novel c-Myc deSUMOylating enzyme. SENP1 directly binds to and deSUMOylates c- Myc in cells and in vitro. Overexpression of wild-type (wt) SENP1, but not its catalytic-inactive mutant (C603S), stabilizes c-Myc and enhances c-Myc transactivation activity. Consistently, knockdown of SENP1 reduces c- Myc levels and suppresses cell proliferation. We further show that c-Myc can be co-modified by ubiquitin and SUMO and SENP1-mediated deSUMOylation reduces c-Myc ubiquitination, suggesting that SUMOylation promotes c-Myc degradation through the ubiquitin-proteasome system. In addition, SENP1 deSUMOylates USP28 whereas USP28 stabilizes SENP1 and Fbw7 reduces SENP1 levels. Thus, c-Myc levels and activity may be dynamically controlled by complex ubiquitination-SUMOylation crosstalk. SENP1 is frequently overexpressed, correlating with the high expression of c-Myc and poor patient survival, in human breast cancers. Together, these results lead to a novel hypothesis that SENP1 functions as a crucial regulator of c- Myc by deSUMOylating c-Myc. To gain further insight into the role of SENP1 in regulating c-Myc protein stability, activity and oncogenicity, we will investigate the molecular and biochemical mechanisms of the regulation of c-Myc by SENP1 in Aim 1, including how SENP1 contributes to c-Myc stabilization, how c-Myc is co-modified by SUMO and ubiquitin, and how it interplays with Fbw7 and USP28 to dynamically control c-Myc turnover. We will elucidate the role of SENP1 in c-Myc-mediated gene regulation in Aim 2 by analyzing whether SENP1 regulates c-Myc binding and turnover at target gene promoters, whether it regulates specific c- Myc target gene programs in response to growth signals, and whether SENP1 regulates the spatial localization of c-Myc in the nucleus. In Aim 3, we will test whether SENP1 potentiates c-Myc-driven transformation and mammary tumorigenesis, whether inhibiting SENP1 suppresses c-Myc-driven tumorigenesis in vivo, and whether SENP1 inhibition is efficacious in breast cancer. Achieving these goals will provide critical insight into how c-Myc is properly regulated by dynamic SUMO modifications, how deregulation of this contributes to tumorigenesis, and whether SENP1 is a promising therapeutic target in human cancers.

项目摘要虽然适当调节的C-MYC水平对于正常的细胞生长和增殖至关重要，但异常 C-MYC的过表达和激活有助于大多数人类癌症。因此，C-MYC水平和活动必须在正常细胞稳态期间受到严格调节。 C-MYC的快速营业额受泛素控制控制依赖性蛋白水解。 C-Myc可以被苏氨酸58磷酸化依赖性泛素泛素化连接酶（E3）复杂的SCFFBW7以及其他各种泛素E3。相反，C-Myc泛素化可能是除泛素化酶（DUB）的作用，包括USP28，USP36和USP37。有趣的是， C-MYC也可以通过小型泛素样修饰剂（SUMOS）来修饰。但是C-Myc sumoylation的功能仍然不清楚，c-myc如何受到desumoylation的影响尚不清楚。我们最近确定了相扑蛋白酶SENP1是一种新型的C-Myc desumoylating酶。 SENP1直接与desumoypares c-结合并粘合。 MYC在细胞和体外。野生型（WT）SENP1的过表达，而不是其催化无效突变体（C603S），稳定C-MYC并增强C-MYC的反式激活活性。一致地，SENP1的敲低会减少C- MYC水平并抑制细胞增殖。我们进一步表明，c-myc可以通过泛素和 SUMO和SENP1介导的desumoylation降低了C-Myc的泛素化，表明Sumoylation 通过泛素 - 蛋白酶体系统促进C-MYC降解。此外，senp1 desumoylates USP28而USP28稳定SENP1和FBW7会降低SENP1水平。因此，C-MYC水平和活动可以通过复杂的泛素化 - 肿瘤串扰动态控制。 SENP1经常过表达，与人类乳房中C-Myc和患者生存不佳的高表达相关癌症。总之，这些结果导致了一个新的假设，即SENP1是C-的关键调节剂 MYC通过Desumoylating C-Myc。为了进一步了解SENP1在调节C-MYC蛋白中的作用稳定性，活性和致癌性，我们将研究分子和生化机制 SENP1在AIM 1中对C-MYC的调节，包括SENP1如何促进C-MYC稳定，C-MYC的方式由Sumo和Ubiquitin共同修饰，以及它如何与FBW7和USP28相互作用以动态控制C-MYC 周转。我们将通过分析来阐明SENP1在C-MYC介导的基因调节中的作用。 SENP1是否调节靶基因启动子的C-MYC结合和周转率，是否调节特定的C- MYC目标基因计划响应增长信号，以及SENP1是否调节空间定位核中的C-Myc。在AIM 3中，我们将测试SENP1是否会增强C-MYC驱动的转型和乳腺肿瘤发生，是否抑制SENP1抑制体内C-Myc驱动的肿瘤发生，并且 SENP1抑制是否在乳腺癌中有效。实现这些目标将为您提供关键的洞察力 C-MYC如何通过动态相扑修改适当调节，这是如何导致这种情况的肿瘤发生，以及SENP1是否是人类癌症中有前途的治疗靶标。