Structure and assembly of membrane proteins at tight junctions

紧密连接处膜蛋白的结构和组装

• 批准号: 10459311
• 负责人: Alex J. Vecchio
• 金额: $ 36.22万
• 依托单位: UNIVERSITY OF NEBRASKA LINCOLN
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10459311
• 关键词: Alzheimer' s Disease; Architecture; Bacterial Toxins; Biochemical; Bioinformatics; Biophysics; Blood - brain barrier anatomy; Cell Adhesion; Cell membrane; Cells; Charge; Complex; Development; Disease; Ear Diseases; Endothelial Cells; Endothelium; Environment; Epidermis; Epithelial; Epithelial Cells; Extracellular Space; Eye diseases; Family; Food Poisoning; Functional disorder; Gland; Goals; Hepatitis; Human; Huntington Disease; Individual; Inflammatory Bowel Diseases; Integral Membrane Protein; Ions; Kidney; Knowledge; Laboratories; Limb structure; Link; Malignant Neoplasms; Membrane; Membrane Proteins; Modification; Molecular; Molecular Conformation; Molecular Disease; Molecular Structure; Organ; Organism; Parkinson Disease; Pathology; Permeability; Protein Family; Proteins; Research; Shapes; Side; Stroke; Structure; Tight Junctions; Tissues; Transport Process; Vertebrates; base; design; experimental study; insight; interdisciplinary approach; macromolecular assembly; membrane assembly; novel therapeutics; programs; reconstruction; scaffold; skin disorder; small molecule; structural biology; wasting

Project Summary Tight junctions (TJs) at the boundaries of endothelial and epithelial cells are critical in the development and function of vertebrates because they enable these tissues to separate, protect, and shape external epidermis and limbs and internal organs and glands. TJs regulate molecular transport through the spaces between individual cells (paracellular) while adhering cellular sheets. TJs perform two vital functions in tissues: 1) form barriers to restrict paracellular flux of small molecules, protecting organisms from the external environment and separating internal body compartments; and 2) creating size- and charge-selective pores, allowing permeability of ions that maintain electrochemical gradients. Numerous proteins amass at TJs to form the macromolecular assemblies necessary for barrier and pore function. But two families of membrane proteins—claudins and TAMPs (TJ-associated Marvel proteins)—predominate TJ assembly, architecture, and function. As these TJ integral membrane proteins (TJIMPs) are the sole components to span intracellular, intramembraneous, and extracellular space, they act as cytoskeletal scaffolds and assemble side-by-side within a membrane (cis) and with TJIMPs from adjacent cell membranes (trans) to form barriers and pores. The molecular structure of TJs is dynamic. Changes in protein composition, interaction, conformation, or modification—useful for assembling TJs to precisely tune paracellular transport under normal conditions—can also be mis-assembled, resulting in pathologies such as cancer, Alzheimer’s, Parkinson’s, Huntington’s, ALS, stroke, food poisoning and inflammatory bowel disease, renal wasting, hepatitis, and diseases of the skin, eyes, and ears. Molecular level insights into TJ structure and dynamics; the mechanisms of assembly that govern barrier and pore function; and how disabling these mechanisms leads to pathologies, remain unresolved matters in our fundamental understanding of TJs. We propose here a comprehensive research program that uses highly interdisciplinary approaches to determine structure–interaction–function relationships between TJIMPs at dynamic TJ microenvironments. These approaches integrate structural biology of TJIMPs and their complexes with information obtained by traditional and state-of-the-art bioinformatics, biochemical, biophysical, and functional experiments. The research program intends to resolve the underlying molecular principles of TJ assembly and disassembly by confronting technical challenges and, in the near-term, by answering specific questions on TJIMP interaction networks, the basis of gut barrier breakdown by a bacterial toxin, and the mechanisms of TJIMP form and function at the blood-brain barrier. The long-term goal of our laboratory is to elucidate the molecular bases for construction, destruction, and reconstruction of TJs, occurring both naturally or via disease-causing mechanisms, and to use the achieved insights to advance design and development of novel therapeutics to remedy TJ-related ailments.

项目总结