Molecular functions of human zinc transporter-8 in pancreatic beta cells

人锌转运蛋白 8 在胰腺 β 细胞中的分子功能

• 批准号: 10321946
• 负责人: Dax Fu
• 金额: $ 49.76万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10321946
• 关键词: Address; Autoantigens; Beta Cell; Binding; Binding Proteins; Biochemistry; Biological; Biological Models; Biology; Biomimetics; Carrier Proteins; Cell physiology; Cell surface; Cells; Cellular Stress; Cellular biology; Client; Complex; Coupling; Crystallization; Cytoplasm; Data; Disease; Endocrine; Endoplasmic Reticulum; Ensure; Equilibrium; Exocytosis; Glucose; Goals; Homeostasis; Homologous Gene; Housekeeping; Human; Human body; Immunoassay; Individual; Inflammation; Inflammatory; Insulin; Islets of Langerhans; Knowledge; Lipids; Location; Mammalian Cell; Mediating; Messenger RNA; Metabolic; Metals; Minor; Modeling; Molecular; Monoclonal Antibodies; Non-Insulin-Dependent Diabetes Mellitus; Pathogenesis; Play; Population; Process; Production; Protein Conformation; Protein Dynamics; Proteins; Proteome; Proteomics; Publishing; Quality Control; Regulation; Research; Role; Secretory Vesicles; Signal Transduction; Specificity; Stimulus; Stress; Structure of beta Cell of islet; Surface; Testing; Time; Tube; Ubiquitination; Vacuum; Zinc; alpha Tubulin; atomic interactions; base; cross reactivity; cytokine; endoplasmic reticulum stress; genetic regulatory protein; insulin secretion; islet; loss of function mutation; response; restoration; spatiotemporal; zinc-binding protein

Abstract Zinc is a ubiquitous biological metal found in about 10% of the eukaryotic proteome. The spatiotemporal zinc dynamics provides crucial cellular signaling opportunities, but also challenges intracellular zinc homeostasis with broad disease implications. Zinc transporters play a central role in regulating cellular zinc balance and subcellular zinc distributions. Current biochemistry of zinc transporters is largely based on purified proteins in test-tubes. However, the molecular functions of zinc transporters in mammalian cells are cell context dependent, vary with subcellular locations and regulated by pathophysiologic stimuli. At present, we have no knowledge of in-cell functions of endogenous zinc transporters at the molecular level. To fill in this knowledge vacuum, we will use an islet-specific zinc transporter ZnT8 and its host cells, the insulin-producing pancreatic β-cells as a mammalian model system to address two questions of the greatest importance to zinc biology: (i) how ZnT8-mediated zinc transport is compartmentalized at the correct subcellular locations to perform intended tasks, (ii) how the biosynthetic burden of ZnT8 is managed by the protein quality control network that ensures clearance of terminally damaged ZnT8 under cell stress. The second question is not directly related to zinc transport, but has a profound impact on β-cell biology with implications in pathogenesis of type-2 diabetes. Our prior studies have uncovered functional coupling of ZnT8 and insulin in two critical cellular processes, glucose-stimulated insulin secretion and inflammation-induced unfolded protein response in the endoplasmic reticulum. The proposed research will characterize subcellular locations and protein levels of endogenous ZnT8 in response to metabolic and inflammatory stress (Aim-1), identify regulators of ZnT8 subcellular functions, and elucidate their mechanism of actions (Aim-2). The proposed research will reveal unprecedented molecular details of ZnT8 subcellular functions in molecular and cellular processes that impact cell biology of host cells, leading to a new paradigm of in-cell molecular functions of zinc transporters in mammalian cells.

抽象的 锌是在大约10％的真核蛋白质组中发现的无处不在的生物金属。时空锌 动态提供了至关重要的细胞信号传导机会，但也挑战了细胞内锌的稳态 广泛的疾病意义。锌转运蛋白在调节细胞锌平衡和亚细胞中起着核心作用 锌分布。锌转运蛋白的当前生物化学主要基于测试管中的纯化蛋白质。 然而，哺乳动物细胞中锌转运蛋白的分子功能取决于细胞情境，随着 亚细胞位置，并由病理生理刺激调节。目前，我们不知道 内源性锌转运蛋白在分子水平的功能。要填写这些知识真空，我们将使用 胰岛特异性锌转运蛋白ZNT8及其宿主细胞，胰岛素产生的胰腺β细胞作为哺乳动物 模型系统解决了两个对锌生物学最重要的问题：（i）Znt8介导的锌如何 在正确的亚细胞位置将运输划分以执行预期任务，（ii）如何 Znt8的生物合成燃烧由蛋白质质量控​​制网络管理，以确保清除 在细胞应力下终止损坏的Znt8。第二个问题与锌运输无直接相关，而是 对β细胞生物学的深远影响，对2型糖尿病的发病机理产生了影响。我们先前的研究有 在两个关键细胞过程中，Znt8和胰岛素的未透明功能耦合，葡萄糖刺激的胰岛素 分泌和炎症引起的内质网中未折叠的蛋白质反应。提议 研究将表征内源性Znt8的亚细胞位置和蛋白质水平，以响应代谢 和炎症应力（AIM-1），识别Znt8亚细胞功能的调节剂，并阐明其机制 行动（AIM-2）。拟议的研究将揭示Znt8亚细胞的前所未有的分子细节 影响宿主细胞细胞生物学的分子和细胞过程的功能，导致新的范式 哺乳动物细胞中锌转运蛋白的细胞内分子功能。