Nutrient Regulation of Cell Physiology by O-GlcNAcylation

O-GlcNAc 酰化对细胞生理学的营养调节

• 批准号: 9754184
• 负责人: GERALD Warren HART
• 金额: $ 28.88万
• 依托单位: UNIVERSITY OF GEORGIA
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-10 至 2020-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9754184
• 关键词: Affect; Affinity; Aging; Alzheimer' s Disease; Binding; Cardiovascular Diseases; Catalytic Domain; Cell Cycle; Cell Nucleus; Cell physiology; Cells; Chromatin; Chronic Disease; Complex; Cytoplasm; Cytoplasmic Protein; DNA; DNA Binding; DNA Methylation; DNA Modification Methylases; DNA-Binding Proteins; DNA-Directed RNA Polymerase; Data; Diabetes Mellitus; Disease; Eating; Enzymes; Epigenetic Process; Etiology; Gene Expression; Genes; Genetic Transcription; Glucose; Goals; Heat-Shock Response; Histones; Holoenzymes; Human; Kinetics; Length; Life; Lymphocyte Activation; Malignant Neoplasms; Mammals; Mediating; Methods; Mitochondrial Proteins; Modification; Molecular; Nerve Degeneration; Nuclear Protein; Nuclear Proteins; Nutrient; O-GlcNAc transferase; Paper; Peptides; Phosphorylation; Phosphotransferases; Plants; Play; Post-Translational Protein Processing; Property; Protein Microchips; Proteins; Proteomics; RNA Polymerase II; Regulation; Role; Signal Transduction; Site; Specificity; Stimulus; Stress; Substrate Specificity; TAF1 gene; TATA-Box Binding Protein; Therapeutic; Toxic effect; Transcriptional Regulation; Work; blood glucose regulation; circadian pacemaker; in vivo; insight; knock-down; mutant; overexpression; promoter; protein B; protein aminoacid sequence; response; sensor; stoichiometry; sugar; therapeutic development; trafficking; transcription factor; transcription factor S-II

The cycling of N-acetylglucosamine on Ser(Thr) residues (O-GlcNAcylation) of nuclear, cytoplasmic and mitochondrial proteins serves as a nutrient sensor to regulate signaling, transcription, and cellular physiology. Abnormal O-GlcNAcylation underlies the etiology of diabetes, cancer and Alzheimer's disease. O-GlcNAcylation regulates nearly every aspect of transcription, including RNA polymerase II, histones, DNA methyltransferases, and nearly all transcription factors. Yet we know very little about the mechanisms involved. TATA-binding protein (TBP) is amongst the most important components of the transcription machinery. Our recent studies indicate that TBP regulated by O-GlcNAcylation in response to nutrients. O-GlcNAcylation has extensive crosstalk with protein phosphorylation and other modifications. However, unlike phosphorylation, which is catalyzed by hundreds of kinases, there is only one highly conserved gene encoding O-GlcNAc transferase (OGT). Nonetheless, OGT site-specifically modifies thousands of proteins. Our data indicate that OGT's substrate specificity is not only determined by its specificity for peptide sequence, but also by its transient associations with other proteins, which dynamically target it to specific substrates. OGT targeting interactions are largely mediated by its tetratricopeptide repeats (TPRs). OGT missing TPRs remains active against small peptides, but has poor activity against full-length proteins. Herein we will investigate two major questions related to O-GlcNAcylation: Specific Aim 1: Continue to Study Glucose Regulation of TATA-binding protein (TBP) via its O-GlcNAcylation. Hypothesis: At certain promoters, glucose regulates TBP DNA-binding and its ability to bend DNA by altering its O- GlcNAcylation. We will systematically elucidate mechanisms and functions of this nutrient regulation of TBP. Three goals: A. Roles of O-GlcNAcylation in the molecular and cellular properties of TBP? B. Roles of O- GlcNAc in TBP's Interactions in the Transcription Cycle. C. O-GlcNAc's In Vivo Roles in TBP-mediated Gene Expression. Specific Aim 2: Continue to Elucidate How OGT is Specifically Targeted to Thousands of Different Protein Substrates? Hypothesis: OGT achieves a high degree of specificity not only by its recognition of peptide sequence, but also by it being targeted to substrates by accessory proteins. This Aim will systematically evaluate both the general and specific roles of OGT binding partners in OGT's activities toward its many substrates. Given O-GlcNAc's importance to mechanisms of chronic disease, such as glucose toxicity in diabetes, cancer and neurodegeneration, elucidation of these mechanisms will not only be key to understanding transcription and signaling, also to uncovering new avenues for therapeutics.

N-乙酰葡萄糖在核，细胞质和 线粒体蛋白是一种营养传感器，可调节信号传导，转录和细胞 生理。异常的O-Glcnacylation是糖尿病，癌症和阿尔茨海默氏病的病因。 O-Glcnacylation几乎调节转录的每个方面，包括RNA聚合酶II，组蛋白，DNA 甲基转移酶和几乎所有转录因子。但是我们对机制知之甚少 涉及。塔塔结合蛋白（TBP）是转录最重要的组成部分之一 机械。我们最近的研究表明，由O-Glcnacylation响应营养的TBP。 O-Glcnacylation具有广泛的串扰，并具有蛋白质磷酸化和其他修饰。然而， 与数百种激酶催化的磷酸化不同，只有一个高度保守的基因 编码O-GLCNAC转移酶（OGT）。尽管如此，OGT位点特异性地修饰了数千种蛋白质。 我们的数据表明，OGT的底物特异性不仅取决于其对肽的特异性 序列，也是通过其与其他蛋白质的瞬时关联，将其动态靶向特定 基材。 OGT靶向相互作用在很大程度上是由其四肽重复序列（TPRS）介导的。 OGT 缺失的TPR对小肽保持活跃，但对全长蛋白的活性较差。 在此，我们将调查与O-Glcnacylation有关的两个主要问题：特定目的1：继续 研究通过其O-Glcnacylation对TATA结合蛋白（TBP）的葡萄糖调节。假设：at 某些启动子，葡萄糖调节TBP DNA结合及其通过改变其O-的弯曲DNA的能力 Glcnacylation。我们将系统地阐明TBP的营养调节的机制和功能。 三个目标：A。O-glcnacylation在TBP的分子和细胞特性中的作用？ B. O-的角色 TBP在转录周期中的相互作用中的GlcNAC。 C. O-GLCNAC在TBP介导的体内角色 基因表达。特定目标2：继续阐明OGT专门针对的方式 数千种不同的蛋白质底物？假设：OGT实现高度特异性而不是 仅通过识别肽序列的识别，也仅通过将其靶向粘液材料。 蛋白质。这个目标将系统地评估OGT绑定伙伴的一般和特定角色 在OGT对其许多底物的活动中。 考虑到O-GLCNAC对慢性疾病机制的重要性，例如糖尿病中的葡萄糖毒性， 癌症和神经变性，阐明这些机制不仅是理解的关键 转录和信号传导，也可以发现治疗疗法的新途径。