Deciphering molecular details of cellular sugar transport and their roles in disease

破译细胞糖转运的分子细节及其在疾病中的作用

• 批准号: 10582470
• 负责人: Jeffrey S Abramson
• 金额: $ 9.23万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10582470
• 关键词: Binding; Biological Assay; Cells; Citric Acid Cycle; Complement; Disease; Electrophysiology (science); Family; Glucose; Golgi Apparatus; Human; Ion Channel; Lipid Bilayers; Lipids; Measures; Mediator of activation protein; Membrane; Membrane Transport Proteins; Metabolic; Methods; Mitochondria; Molecular; Mutation; Non-Insulin-Dependent Diabetes Mellitus; Organelles; Organism; Outer Mitochondrial Membrane; Parents; Pathway interactions; Pharmacologic Substance; Physiology; Process; Production; Property; Protein Isoforms; Proteins; Resolution; Role; Sialic Acids; Site; Sodium; Solid; Source; Structure; System; Therapeutic; Voltage-Dependent Anion Channel; inhibitor; pathogen; proteoliposomes; radioligand; reconstitution; sialic acid permease; small molecule; structural biology; sugar; sugar nucleotide; transport inhibitor; virtual

Abstract Sugars, in particular glucose, are not only a ubiquitous cellular fuel source in virtually all organisms, but also serve as critical metabolic intermediates in which activated glucose molecules are transported to the ER and Golgi and used for glycosylating proteins, lipids and other organic compounds as part of the biosynthetic-secretory pathway. To accomplish these diverse and localized functions, the body utilizes membrane transporters and channels to transfer glucose and its intermediates across the otherwise impermeable membrane lipid bilayer that surrounds all cells and organelles. Secondary active transporters are key mediators in this process. Alternatively, the Voltage Dependent Anion Channel funnels glucose intermediates into the mitochondria where they enter the TCA cycle for the production of ATP. In their essential function for physiology, these proteins are implicated in numerous diseases and are designated targets for pharmaceutical compounds. In the parent R35 entitled, “Deciphering molecular details of cellular sugar transport and their roles in disease” we aim to characterize the structure and function of several families of transporters involved in cellular sugar and metabolite transport. Specifically, we want to study the Sodium Glucose Cotransporter (SGLT), Nucleotide Sugar Transporters (NST) and Sialic Acid Transporter (SiaT) and the Voltage-Dependent Anion Channel (VDAC). Human SGLTs are well known targets for treating Type II diabetes, but the molecular details of inhibition and the functional differences between isoforms are not well understood. This is in large part due to the lack of structural information. NSTs import various activated sugar compounds into the Golgi and ER, whereas SiaT serves to import scavenged sialic acids from its host. Differences between eukaryotic and pathogen NSTs could be exploited for therapeutic purposes. However, this family of transporters is still largely uncharacterized. VDAC is the central mediator of metabolite exchange through the outer mitochondrial membrane. Despite this critical role, key aspects of its functional gating and substrate transport are not well understood. Again, we hope that resolving additional structures of VDAC will help to answer these remaining questions. Our structural biology approach is complemented by functional studies to obtain a complete picture of sugar transport at an atomic resolution. We need to assess the functionality of heterologously- expressed proteins during the early stages of project. After obtaining the structures, we plan to interogate them by inserting mutations at critical sites identified in the structures. Furthermore, we plan to screen small-molecules as potential inhibitors. Electrophysiology on solid-supported membranes is a suitable highthroughput method for all stages of the proposed project.

摘要 糖，特别是葡萄糖，不仅是几乎所有生物体中普遍存在的细胞燃料来源， 也作为关键的代谢中间体，其中活化的葡萄糖分子被转运到 内质网和高尔基体，并用于糖基化蛋白质，脂质和其他有机化合物的一部分， 生物合成-分泌途径为了实现这些多样化和局部化的功能，身体 利用膜转运蛋白和通道将葡萄糖及其中间产物转移穿过膜， 包围所有细胞和细胞器的另一种不可渗透的膜脂质双层。二次 主动转运蛋白是这一过程中的关键介质。或者，电压依赖性阴离子 通道将葡萄糖中间体漏斗状地输送到线粒体中，在线粒体中它们进入TCA循环， 生产ATP。在其生理学的基本功能中，这些蛋白质涉及许多 疾病，并且是药物化合物的指定靶标。 在题为“破译细胞糖转运及其代谢的分子细节”的亲本R35中， 在疾病中的作用”，我们的目标是表征几个转运蛋白家族的结构和功能 参与细胞糖和代谢物的运输。具体来说，我们想研究葡萄糖钠 协同转运蛋白（SGLT）、核苷酸糖转运蛋白（NST）和唾液酸转运蛋白（SiaT），以及 电压依赖性阴离子通道（VDAC）。人SGLT是众所周知的用于治疗型糖尿病的靶点。 II型糖尿病，但抑制的分子细节和亚型之间的功能差异是 没有很好地理解。这在很大程度上是由于缺乏结构信息。NST导入各种 活化的糖化合物进入高尔基体和ER，而SiaT用于输入清除的唾液酸 酸从其宿主。真核生物和病原体NST之间的差异可以用于 治疗目的。然而，这个家庭的运输仍然是在很大程度上没有特点。VDAC是 通过线粒体外膜进行代谢物交换的中心介质。尽管如此 关键作用，其功能门控和底物运输的关键方面还没有很好地理解。我再次重申， 我们希望解决VDAC的附加结构将有助于回答这些剩余的问题。 我们的结构生物学方法是由功能研究补充，以获得一个完整的图片 以原子级的分辨率传输糖。我们需要评估异源的功能- 在项目的早期阶段表达蛋白质。在获得结构后，我们计划 通过在结构中识别的关键位点插入突变来相互作用。此外，我们计划 筛选小分子作为潜在的抑制剂。固体支撑膜上的电生理学是 一个合适的高通量的方法，为所有阶段的拟议项目。