Project 3/Struct. of the CDB3:ankyrin:protein 4.2 complex in erythrocytes by EPR

项目 3/结构。

• 批准号: 7449168
• 负责人: ALBERT H BETH
• 金额: $ 19.52万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-05-01 至 2013-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7449168
• 关键词: Actins; Adaptor Signaling Protein; Affinity; Aldehyde-Lyases; Amino Acids; Anion Exchangers (Proteins); Ankyrin Repeat; Ankyrins; Architecture; Binding; Binding Proteins; Blood Circulation; Blood capillaries; Cardiovascular system; Cell Shape; Cell Size; Cell membrane; Cells; Class; Complex; Condition; Cytoplasmic Tail; DNA Sequence Rearrangement; Data; Defect; Disease; Docking; Erythrocyte Membrane; Erythrocytes; Exhibits; Family; Fluorescence; Fructosediphosphate Aldolase; Glycophorin C; Goals; Hemoglobin; Hemolysis; Hemolytic Anemia; Hereditary Spherocytosis; Homology Modeling; Human; Integral Membrane Protein; Knowledge; Label; Laboratories; Lead; Length; Lipid Bilayers; Literature; Mechanics; Membrane; Membrane Proteins; Methods; Microcirculation; Modeling; Molecular; Peripheral; Phenotype; Physiologic pulse; Point Mutation; Positioning Attribute; Property; Proteins; Pulse taking; Range; Relative (related person); Reporting; Resolution; Shapes; Side; Site; Skeleton; Spectrin; Spin Labels; Structural Models; Structure; Surface; Testing; Work; adapter protein; band 3 protein Tuscaloosa; base; capillary; dimer; human SYK protein; insight; molecular dynamics; molecular modeling; protein 4.1; protein protein interaction; shear stress

Human erythrocytes exhibit an unusual biconcave disc shape together with remarkable stability and deformability, all of which are necessary for their survival in the circulatory system. It is now well established that the unusual cell shape and membrane mechanical properties are due in large part to the presence of an extensive membrane skeleton, composed primarily of the proteins spectrin and actin, that lines the inner membrane surface and to specific bridging interactions between this membrane skeleton and intrinsic membrane proteins in the lipid bilayer. The spectrin-actin skeleton associates with the membrane bilayer via two types of contacts, one involving short actin protofilaments and protein 4.1 interacting with the cytoplasmic domain of glycophorin C, and the second involving the bridging protein ankyrinR and protein 4.2 interacting with the cytoplasmic domain of the anion exchange protein (AE1). This project seeks to characterize the structure of the complex of proteins that forms this second class of bridging interactions in human erythrocytes. This focus is dictated by the knowledge that alterations in this second class of interactions results in spherical erythrocytes with decreased cell size and increased fragility, a condition known clinically as hereditary spherocytosis (HS). HS is a spectrum of diseases, occurring in one family out of 2,000 to 3,000, that present clinically as varying degrees of hemolytic anemia resulting from hemolysis of the spherical erythrocytes when they traverse the microcirculation. Recent data have indicated that 15-20% of HS cases are attributable to AE1 defects and ~50% of HS cases result from ankyrin defects (4). A reduction in protein 4.2 binding to the membrane is also a common finding (5). Studies over the past three decades have led to the definition of the intrinsic and peripheral membrane proteins that assemble to stabilize the erythrocyte membrane (reviewed in (6,7)). A central player in the assembly of these proteins is the cytoplasmic domain of AE1 (also known as band 3). The cytoplasmic domain of band 3 (cdb3) has been hypothesized to serve as an organizing center for binding ankyrinR (8) and protein 4.2 (9) as well as other cytosolic proteins including GAPDH (10,11), aldolase (12), phosphofructokinase (13), hemoglobin (14), hemichromes (15), and p72syk (16). Figure 1 shows a schematic diagram of some of the key protein-protein interactions that have been elucidated.

人红细胞显示出不寻常的双凹面盘形，同时具有显著的稳定性， 变形性，所有这些都是它们在循环系统中生存所必需的。现在得到确认的 不寻常的细胞形状和膜机械性能在很大程度上是由于存在一个 主要由血影蛋白和肌动蛋白组成的广泛的膜骨架，排列在细胞的内部 膜表面和这种膜骨架和内在之间的特定桥接相互作用 脂质双层中的膜蛋白。血影蛋白-肌动蛋白骨架通过以下方式与膜双层结合： 两种类型的接触，一种涉及短肌动蛋白原丝和蛋白4.1与细胞质相互作用， 结构域的血型糖蛋白C，第二个涉及桥接蛋白锚定R和蛋白4.2相互作用 与阴离子交换蛋白（AE 1）的胞质结构域。该项目旨在描述 在人类红细胞中形成第二类桥接相互作用的蛋白质复合物的结构。 这种关注是由这样的知识所决定的，即在这第二类相互作用中的改变导致球形 红细胞体积减小，脆性增加，临床上称为遗传性 球形红细胞增多症（HS）。HS是一系列疾病，发生在2,000至3,000个家庭中的一个家庭中， 临床上表现为球形红细胞溶血导致的不同程度的溶血性贫血， 它们穿过微循环。最近的数据表明，15-20%的HS病例可归因于AE 1 缺陷和~50%的HS病例由锚蛋白缺陷引起（4）。蛋白质4.2结合的减少 膜也是一种常见的发现（5）。 在过去的三十年里，研究已经导致了内在膜和外周膜的定义 组装以稳定红细胞膜的蛋白质（综述见（6，7））。一个中心的球员， 这些蛋白质的装配是AE 1的胞质结构域（也称为带3）。胞质结构域 已假设带3（cdb 3）的一个区域作为结合锚定受体（8）和蛋白质的组织中心 4.2（9）以及其它胞质蛋白，包括GAPDH（10，11），醛缩酶（12），磷酸果糖激酶（13）， 血红蛋白（14）、半色素（15）和p72 syk（16）。图1显示了一些关键的示意图 蛋白质间的相互作用已被阐明。