Structural basis of KATP channel gating

KATP通道门控的结构基础

基本信息

批准号：
10549857
负责人：
Show-Ling Shyng
金额：
$ 43.82万
依托单位：
OREGON HEALTH & SCIENCE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-02-07 至 2025-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10549857
关键词：
ATP-Binding Cassette Transporters Affect Antidiabetic Drugs Binding Biochemical Biogenesis Blood Vessels Brain CRSP3 gene Carbamazepine Cells Cellular Metabolic Process Chemicals Complex Cryoelectron Microscopy Data Defect Detergents Developmental Delay Disorders Dimerization Disease Distal Drug Design Epilepsy Functional disorder Funding Genes Genetic Polymorphism Glucose Glyburide Goals Grant Health Heart Hormone secretion Human Hypoglycemia Impairment Ion Channel Knowledge Lead Ligands Mediating Membrane Membrane Proteins Methods MgADP MgATP Molecular Molecular Chaperones Monitor Mutation N-terminal Non-Insulin-Dependent Diabetes Mellitus Nucleotides Outcome Persistent Hyperinsulinemia Hypoglycemia of Infancy Pharmaceutical Preparations Phosphatidylinositol 4,5-Diphosphate Physiological Positioning Attribute Potassium Potassium Channel Publishing Regulation Resolution Review Literature Risk Structure Structure of beta Cell of islet Structure-Activity Relationship Surface Syndrome Testing Therapeutic Transmembrane Domain biochemical tools biophysical tools conformational conversion crosslink design gain of function mutation glucose metabolism hormone regulation human disease improved inhibitor innovation insulin secretion inward rectifier potassium channel ischemic injury loss of function mutation molecular dynamics mutant nanodisk neonatal diabetes mellitus novel particle pharmacologic preservation protein complex reconstitution repaglinide sulfonylurea receptor trafficking

项目摘要

PROJECT SUMMARY ATP-sensitive potassium (KATP) channels couple cell metabolism to membrane excitability and are critical for many physiological functions. They are unique membrane protein complexes formed by four inwardly rectifying K+ channel (Kir6.1 or Kir6.2) subunits and four sulfonylurea receptor (SUR1 or SUR2) subunits. This grant is focused on KATP channels consisting of Kir6.2 and SUR1, which have a key role in glucose-stimulated insulin secretion in pancreatic β-cells. Loss-of-function mutations in these channels cause congenital hyperinsulinism and hypoglycemia, whereas gain-of-function mutations cause neonatal diabetes and in severe cases DEND (Developmental delay, Epilepsy, and Neonatal Diabetes) syndrome. In addition, KATP gene polymorphisms increase risk for type 2 diabetes. Our long-term goal is to understand the structure-function relationship of KATP channels in order to develop mechanism-based therapies for disease caused by KATP dysfunction. Over the past three funding cycles, we have made significant progress towards this goal. Most particularly, using single-particle cryo-electron microscopy (cryoEM) we recently obtained high-resolution structures of the channel bound with the physiological inhibitor ATP and the anti-diabetic drug glibenclamide (glyburide). This opened a new chapter for the field, enabling us to understand the structural basis of KATP channel assembly and gating in health and disease, at near atomic detail and in the context of full channel structure. Our group is uniquely positioned to help lead this effort by integrating our cryoEM capability with the extensive molecular, biochemical, and biophysical tools and knowledge we have amassed over the course of this grant. In this renewal application, we propose to tackle the most important yet challenging problems remaining in the field. Our overarching hypothesis is that SUR1 assembles with and regulates the function of Kir6.2 through specific structural interactions that are regulated by physiological and pharmacological ligands. We will use a combination of structural, molecular dynamics simulation and functional approaches to test the hypothesis in three interwoven but independent Specific Aims. (1) Elucidate KATP channel assembly mechanisms guided by our cryoEM structures. (2) Identify and monitor interactions between SUR1, Kir6.2, and ligands that are critical for channel opening and closure to understand the structural mechanisms governing channel gating. (3) Determine open state structures of KATP channels by cryoEM to understand the conformational transition during gating. The proposal has a strong scientific premise built on our rigorous preliminary and published studies as well as a careful review of the literature. The proposal is innovative as it will generate new structures and test conceptually novel mechanistic hypotheses on channel gating and assembly emanated from the recent cryoEM structures. Successful outcome will have significant impact on advancing our structural knowledge of channel regulation to facilitate mechanistic drug design for disease caused by KATP channel dysfunction. Further, the outcome will have broad implications for many other ABC transporters and ion channels important for human health.

项目摘要 ATP敏感钾（KATP）通道将细胞代谢夫妇与膜相对它们是由四个内部整流K ++形成的独特的膜蛋白复合物通道（Kir6.1或Kir6.2）亚基和四个磺酰脲受体（SUR1或SUR2）亚基。在由KIR6.2和SUR1组成的KATP通道上，它们在葡萄糖刺激的胰岛素分泌中具有关键作用胰腺β细胞。低血糖，而功能收益突变会导致新生儿糖尿病，在严重的情况下导致（发育延迟，癫痫和新生儿糖尿病）此外，KATP基因多态性增加2型糖尿病的风险。 KATP通道以开发基于机制的KATP功能障碍引起的疾病疗法。在过去的树木资金周期中，我们已经朝着这个目标取得了重大进步。使用单粒子冷冻电子显微镜（冷冻）我们最近获得了高分辨率结构与生理抑制剂ATP和抗糖尿病药物（Glibenbelide）结合的通道为该领域开了一个新的篇章，使我们能够理解Katp Channel sistorty Andly的结构基础健康和疾病的门控，几乎是原子的细节和完整的渠道结构通过将我们的冷冻可粘性与广泛的分子融合在一起，以帮助实现这一EFFOS的独特位置生物化学和生物物理工具和知识在这项续签的过程中积累了应用，我们建议解决该领域剩下的最重要但最具挑战性的问题。总体假设是SUR1通过特定而与Kir6.2的功能组装并调节功能通过生理和药物配体进行的结构相互作用。结构，分子动力学模拟和功能方法的结合，以检验假设三个交织但独立的特定目的。我们的冷冻结构。通道打开和闭合，以了解控制通道门控的结构机制 katp渠道的开放状态结构通过冷冻渠道了解提案具有强大的科学前提，基于我们严格的初步和发表的研究对文献的仔细审查是创新的，因为它将生成新的结构最近的冷冻结构散发出关于通道门控和组装的新型机械假设。成功的结果将对推进我们对渠道调节的结构知识产生重大影响促进由KATP通道功能障碍引起的疾病的机械药物设计。对许多其他ABC转运蛋白和离子渠道对人类健康很重要的含义。