Defining OGT's Essential Functions to Guide Therapeutic Approaches

定义 OGT 的基本功能以指导治疗方法

基本信息

批准号：
10316265
负责人：
Suzanne Walker
金额：
$ 44.31万
依托单位：
HARVARD MEDICAL SCHOOL
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-02-01 至 2024-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10316265
关键词：
Active Sites Address Affect Asparagine Aspartate Binding Biochemistry Biological Process Biology Cardiometabolic Disease Cell Nucleus Cell Proliferation Cell Survival Cell physiology Cells Combined Modality Therapy Complications of Diabetes Mellitus Cytoplasm Cytoplasmic Protein Drug Targeting Foundations Funding Genes Genetic Genetic Predisposition to Disease Genetic Transcription Growth Human Insulin Resistance Knowledge Lead Length Link Location Malignant Neoplasms Mammals Mediating Metabolic Diseases Methods Mitochondrial Proteins Nuclear Proteins O-GlcNAc transferase Other Genetics Pathway interactions Permeability Phenotype Physiological Physiology Process Proteins Proteomics Role Scientific Advances and Accomplishments Side Supporting Cell System Technology Testing Therapeutic Variant Vertebral column Work cancer therapy cancer type conditional knockout design experimental study glycosylation glycosyltransferase host cell factor C1 inhibitor insight knock-down nanomolar novel scaffold small molecule inhibitor therapeutic target tool

项目摘要

PROJECT SUMMARY O-GlcNAc transferase (OGT), an essential human protein, attaches N-acetylglucosamine (GlcNAc) to Ser/Thr residues of proteins in the nucleus and cytoplasm. Dysregulated OGT expression and activity have been linked to insulin resistance, diabetic complications, and cancer, making OGT a possible drug target. Developing approaches to exploit OGT as a target requires understanding its physiological roles and the mechanisms by which it achieves them. Studies to probe OGT's physiological roles have relied heavily on knockdown (KD) or conditional knockout (KO) experiments and the resulting phenotypes have been attributed to loss of O-GlcNAc. However, OGT has a second catalytic activity and also binds cellular proteins that it does not glycosylate; some phenotypes attributed to O-GlcNAc loss may therefore be due to loss of other activities. Previously, the importance of OGT's catalytic and noncatalytic functions could not be assessed because methods to replace endogenous OGT with variants did not exist. We have now established methods to replace OGT and will analyze cells containing specifically altered copies to deconvolute OGT's physiological roles. Growth phenotypes, quantitative proteomics, and biochemistry will be used to address several questions. Is OGT's noncatalytic scaffolding activity a major driver of physiology and what pathways are linked to it? What is the shortest OGT construct that still supports cell survival and what proteins does it glycosylate and bind? How do OGT's substrates and binding partners interact with the TPR domain and are there opportunities to target specific regions of this domain? We will also use a small molecule inhibitor we recently developed in a chemogenomics screen to identify genetic vulnerabilities to loss of O-GlcNAc. In addition to advancing scientific knowledge about one of the most fundamentally important proteins in mammalian biology, the work in this proposal will provide the foundation to guide approaches to exploit OGT as a therapeutic target.

项目摘要 O-GLCNAC转移酶（OGT），一种必需的人蛋白，将N-乙酰葡萄糖（GLCNAC）连接到Ser/Thr 细胞核和细胞质中蛋白质的残基。 OGT表达和活性失调已连接胰岛素抵抗，糖尿病并发症和癌症，使OGT成为可能的药物靶标。发展利用OGT作为目标的方法需要了解其生理作用和机制它实现了他们。探测OGT生理角色的研究已严重依赖敲低（KD）或有条件的敲除（KO）实验和所得的表型归因于O-GLCNAC的损失。但是，OGT具有第二种催化活性，还结合了其不糖基酸的细胞蛋白。一些因此，归因于O-GLCNAC损失的表型可能是由于其他活动的丧失。以前，无法评估OGT催化和非催化功能的重要性，因为替代方法具有变体的内源性OGT不存在。我们现在已经建立了替换OGT的方法，并将分析包含特异性副本的细胞为变形OGT的生理角色。生长表型，定量蛋白质组学和生物化学将用于解决几个问题。是OGT的非催化性脚手架活动是生理学的主要驱动力，哪些途径与之相关？最短的OGT是什么仍然支持细胞存活的构造以及它糖基化和结合的蛋白质？ OGT如何底物和约束伙伴与TPR领域互动，并且有机会针对特定这个领域的区域？我们还将使用我们最近在化学组学中开发的小分子抑制剂筛选以识别遗传脆弱性损失O-GLCNAC。除了促进有关科学知识该提案中的工作将是哺乳动物生物学中最重要的蛋白质之一，将提供指导方法将OGT作为治疗目标的基础。