Structure and Function of Tetraspanin Complexes

四跨膜蛋白复合物的结构和功能

• 批准号: 10707156
• 负责人: Stephen C. Blacklow
• 金额: $ 79.88万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-19 至 2027-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10707156
• 关键词: Alzheimer' s Disease; Amyloid beta-Protein; Auditory system; B-Cell Activation; B-Cell Antigen Receptor; B-Cell Development; B-Lymphocytes; Binding; Biochemical; Biological; Biological Assay; Biological Process; CD19 gene; CD81 gene; CRISPR/Cas technology; Cells; Chemicals; Common Variable Immunodeficiency; Complex; Coupled; Cryoelectron Microscopy; Cysteine; Defect; Development; Disease; Dissection; Dissociation; Event; Family; Family member; Follow-Up Studies; Foundations; Future; Genitourinary system; Goals; Human; Human Biology; Immune system; Integral Membrane Protein; Investigation; Knock-out; Knowledge; Label; Ligands; Low affinity IgE receptor; Maps; Mass Spectrum Analysis; Mediating; Membrane; Metalloproteases; Molecular; Mus; Organism; Output; Pathway interactions; Peptide Hydrolases; Peroxidases; Phosphorylation; Physiological; Physiology; Positioning Attribute; Process; Production; Protein Precursors; Proteins; Receptor Signaling; Regulation; Reproductive system; Resolution; Role; Signal Transduction; Signal Transduction Pathway; Spices; Stimulus; Structure; Structure-Activity Relationship; T-Cell Proliferation; T-Cell Receptor; Therapeutic; Time; Visualization; Work; alpha secretase; ascorbate; beta secretase; cytokine; extracellular; inhibitor; insight; loss of function mutation; member; nanoenvironment; notch protein; receptor; response; spatiotemporal; trafficking

Project Summary Tetraspanins are an ancient and exceptionally well-conserved family of four pass transmembrane proteins – numbering 33 unique members in humans – that have essential but poorly understood functions in many different cellular contexts. Among tetraspanin proteins, CD81 and the C8 subfamily stand out as particularly important in human biology. CD81 is a binding partner of CD19 in the B cell co-receptor complex, a key regulator of B cell receptor (BCR) signaling. Relatively little is known, however, about how the dynamic association of CD81 with CD19 regulates its association with the B cell receptor and ability to induce a signaling response, critical knowledge gaps that impede therapeutic efforts to modulate or target this pathway. The subset of tetraspanins with eight extracellular cysteine residues (the “C8” tetraspanins) facilitate the maturation and function of the transmembrane metalloprotease ADAM10, which has numerous important roles in physiology and disease. In the immune system, ADAM10 promotes T cell proliferation and cytokine production as the primary sheddase of the low-affinity IgE receptor CD23, and it cleaves Lag-3 in response to stimulation of the T cell receptor. ADAM10 also catalyzes ligand-dependent physiologic Notch cleavage, an essential step in Notch signal transduction, and is the protease responsible for constitutive alpha secretase processing of the Alzheimer’s precursor protein APP, resulting in production of a non-toxic product instead of the toxic A-beta (Aβ) fragment produced by beta- secretase. The objective of this work is to provide a deep and comprehensive understanding of the molecular basis for the function of CD81 and the C8 tetraspanins using structural, biochemical, and dynamic approaches, building from our recent progress in visualizing the structure of CD81 in its free and CD19-bound states. To achieve this goal, we plan to elucidate the dynamics of the CD19-CD81 co-receptor complex in response to B cell activation, determine the molecular basis for recognition of ADAM10 by C8 tetraspanins, and uncover how C8-tetraspanin binding to ADAM10 modulates substrate selection and proteolytic activity. Together, successful completion of these aims will provide a deep understanding of how CD81 modulates signal transduction by the B cell co-receptor, and how the C8 tetraspanins influence ADAM10 metalloprotease function. These findings will inform future therapeutic efforts targeting these important biological processes.

项目摘要 四翼烷蛋白是一个古老且保守良好的四个通过跨膜蛋白的家族 - 在人类中编号33位独特的成员 - 在许多不同的不同 蜂窝上下文。在四翼烷蛋白蛋白中，CD81和C8亚家族在 人类生物学。 CD81是B细胞共受体复合物中CD19的结合伙伴，B细胞的关键调节剂 接收器（BCR）信号传导。但是，关于CD81的动态关联如何与 CD19调节其与B细胞接收器的关联，并诱导信号响应的能力，关键 阻碍治疗努力调节或针对这一途径的知识差距。四翼烷蛋白的子集 具有八个细胞外半胱氨酸残基（“ C8”四叠蛋白酶），促进了该残基的成熟和功能 跨膜金属蛋白酶ADAM10，在生理和疾病中具有许多重要作用。在 免疫系统ADAM10促进T细胞增殖和细胞因子的产生，作为主要的Sheddase 低亲和力IgE受体CD23，并响应T细胞受体的刺激而切割滞后3。 ADAM10 还催化了配体依赖性生理凹槽的裂解，Notch信号转导的重要步骤和 是负责阿尔茨海默氏症前体蛋白APP的组成型α泌尿酶加工的蛋白质， 导致产生无毒产品，而不是由β-产生的有毒A-beta（Aβ）片段 分泌酶。这项工作的目的是提供对分子的深刻而全面的理解 使用结构，生化和动态方法的CD81和C8四跨载质的功能的基础， 从我们最近在其自由和CD19约束状态下可视化CD81结构的进展。到 实现此目标，我们计划阐明响应B的CD19-CD81共受体复合物的动力学 细胞激活，确定C8四翼烷蛋白识别ADAM10的分子基础，并发现如何发现 与ADAM10结合的C8-四叠素蛋白调节底物选择和蛋白水解活性。在一起，成功 这些目的的完成将对CD81调节信号转导的深入了解 B细胞共受体，以及C8四叠蛋白酶如何影响ADAM10金属蛋白酶功能。这些发现会 为针对这些重要的生物学过程的未来治疗努力提供信息。