Regulation of SOX Proteins by Methylation-dependent Proteolysis in Stem Cells and Development

干细胞和发育中甲基化依赖性蛋白水解对 SOX 蛋白的调节

基本信息

批准号：
10531566
负责人：
HUI ZHANG
金额：
$ 30.96万
依托单位：
UNIVERSITY OF NEVADA LAS VEGAS
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-12-01 至 2024-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10531566
关键词：
Alleles Animal Model Animals Anophthalmos Binding Biological Process Bladder Brain Cell Cycle Cells Chromatin Cochlea Complex Coupled DNA Methylation DNA Repair DNA Sequence Alteration DNA biosynthesis Defect Development Disease Dose E2F transcription factors Ear Ectoderm Embryo Embryonic Development Endoderm Engineering Epigenetic Process Epithelium Esophagus Eye GLI3 gene Gene Amplification Gene Expression Regulation Genes Genetic Growth HIF1A gene Homeostasis Human Impairment KDM1A gene Learning Disabilities Lysine Malignant Neoplasms Malignant neoplasm of brain Malignant neoplasm of esophagus Malignant neoplasm of lung Mass Spectrum Analysis Mesoderm Methylation Microphthalmos Motor Skills Mus Mutant Strains Mice Mutation Ovary PIK3CG gene PTEN gene Pathologic Pathway interactions Pattern Phenotype Phosphorylation Phosphotransferases Physiological Play Pluripotent Stem Cells Protein Dynamics Protein Methylation Proteins Proteolysis Proteomics Proto-Oncogene Proteins c-akt Regulation Research Retina Role Seizures Signal Transduction Skin Syndrome TAL1 gene TP53 gene Testis Threonine Tissues Transcriptional Regulation Tumor Suppressor Proteins adult stem cell blastomere structure brain abnormalities brain cell cell type developmental disease embryo cell embryo tissue embryonic stem cell epigenetic regulation fetal stem cell histone methylation induced pluripotent stem cell insight loss of function mutation malignant breast neoplasm methyl group motor learning mutant nervous system disorder neural non-histone protein novel overexpression pluripotency prevent protein degradation self-renewal stem cell function stem cell model stem cells synergism transcription factor ubiquitin ligase ubiquitin-protein ligase

项目摘要

Project Summary The CRL4 ubiquitin ligase complexes regulate many important biological processes such as DNA replication, DNA repair, transcriptional regulation, and epigenetic inheritance of DNA methylation. We recently found that CRL4 also regulates the self-renewal and pluripotency of embryonic stem cells (ESCs) through important stem cell proteins such as SOX2 (SRY-box2). SOX2 is a dose-dependent master transcriptional factor that plays a key role in regulating the self-renewal and pluripotency or multipotency of ESCs, iPSCs, and many fetal and adult stem cells. In ESCs, an increase of SOX2 promotes development into ectoderm and mesoderm lineages, while loss or reduction of SOX2 induces differentiation into endoderm and trophectoderm lineages. Even at the 4-cell embryonic stage, the heterogeneous binding of SOX2 to target genes determines the first lineage decision. In human, loss-of-function mutations on a single Sox2 allele is sufficient to cause the familial anophthalmia/microphthalmia syndrome associated with seizures, brain abnormalities, slow growth, delayed motor skills and learning disability. Conversely, gene amplification and over-expression of SOX2 are frequently associated with many poorly differentiated cancers including lung, esophagus, brain, and breast cancers. However, it remains unclear how the SOX2 protein level is regulated in various stem/progenitor cells during development and tissue homeostasis. We recently found that the protein stability of SOX2 is regulated by a novel CRL4-based proteolytic mechanism using lysine methylation as a proteolytic trigger in ESCs and other related cells. Genetic mutation of this particular CRL4 function impairs embryonic development. We propose to unravel the function and regulation of this novel and important CRL4-based proteolytic mechanism in regulating self-renewal and pluripotency of ESCs and during embryonic development. Our specific aim 1 is to define the roles of CRL4-based ubiquitin E3 ligases that target the methylated SOX2 protein for degradation. Our specific aim 2 is to determine how the levels of methylated SOX2 proteins are dynamically regulated during the self-renewal of ESCs. In our specific aim 3, we propose to examine how the function of SOX2 is regulated in animal development using specific genetic mutants defective in the methylation- dependent proteolysis pathway. Since SOX2 is central to many stem cells and pathological loss or elevation of SOX2 levels underlies many diseases, our studies should reveal a novel paradigm by which the self-renewal and pluripotency or multipotency of various stem cells are regulated.

项目概要 CRL4 泛素连接酶复合物调节许多重要的生物过程，例如 DNA DNA 甲基化的复制、DNA 修复、转录调控和表观遗传。我们最近发现CRL4还调节胚胎干细胞的自我更新和多能性 (ESC) 通过重要的干细胞蛋白，例如 SOX2 (SRY-box2)。 SOX2 具有剂量依赖性主转录因子在调节自我更新和多能性或 ESC、iPSC 以及许多胎儿和成人干细胞的多能性。在 ESC 中，SOX2 增加促进外胚层和中胚层谱系的发育，同时 SOX2 的损失或减少诱导分化为内胚层和滋养外胚层谱系。即使在 4 细胞胚胎阶段， SOX2 与靶基因的异质结合决定了第一个谱系决策。在人类中，单个 Sox2 等位基因的功能丧失突变足以导致家族性遗传无眼症/小眼症综合征与癫痫发作、大脑异常、生长缓慢、运动技能迟缓和学习障碍。相反，基因扩增和过度表达 SOX2 通常与许多低分化癌症相关，包括肺癌、食道癌、脑癌和乳腺癌。然而，目前尚不清楚 SOX2 蛋白水平如何在发育和组织稳态过程中的各种干/祖细胞。我们最近发现 SOX2 的蛋白质稳定性由使用赖氨酸的基于 CRL4 的新型蛋白水解机制调节甲基化作为 ESC 和其他相关细胞中的蛋白水解触发器。这种特殊的基因突变 CRL4 功能损害胚胎发育。我们建议阐明这种新颖且重要的基于 CRL4 的蛋白水解机制在调节自我更新和 ESC 的多能性和胚胎发育过程。我们的具体目标 1 是定义以下角色：基于 CRL4 的泛素 E3 连接酶，靶向甲基化 SOX2 蛋白进行降解。我们的具体目标 2 是确定甲基化 SOX2 蛋白的水平如何在 ESC 的自我更新。在我们的具体目标 3 中，我们建议研究 SOX2 的功能如何使用甲基化缺陷的特定基因突变体在动物发育中进行调节依赖的蛋白水解途径。由于 SOX2 对许多干细胞和病理性丢失或 SOX2 水平升高是许多疾病的基础，我们的研究应该揭示一种新的范式其调节各种干细胞的自我更新和多能性。