Novel mechanisms of TCR quality control

TCR质量控制的新机制

• 批准号: 8420430
• 负责人: Linda M Hendershot
• 金额: $ 8.75万
• 依托单位: ST. JUDE CHILDREN'S RESEARCH HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-02-07 至 2015-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8420430
• 关键词: Address; Anabolism; Antibodies; Attention; Biologic Characteristic; Biological Assay; Biological Models; CD3 Antigens; Cell Culture Techniques; Cell Surface Receptors; Cell surface; Cells; Characteristics; Charge; Client; Complex; Data; Development; Endoplasmic Reticulum; Ensure; Evolution; Extracellular Domain; Immune response; Immune system; In Vitro; Individual; Integral Membrane Protein; Jaw; Kinetics; Literature; Measures; Membrane; Methods; Modeling; Molecular; Molecular Chaperones; Monitor; Organism; Pathway interactions; Play; Polyproteins; Process; Property; Proteins; Proteolysis; Quality Control; Receptor Cell; Reporting; Resolution; Role; Site; T-Cell Receptor; Techniques; Transmembrane Domain; Travel; Vertebrates; Work; base; disulfide bond; extracellular; in vivo; insight; interdisciplinary approach; invariant chain; membrane assembly; novel; oxidation; polypeptide; protein folding; receptor; research study; stoichiometry

DESCRIPTION (provided by applicant): The ¿¿T-cell receptor is essential for major functions of the adaptive immune system and is one of the most complex cell surface receptors. It is composed of eight polypeptide chains that must be assembled in the ER in the proper stoichiometry for it to perform its vital functions. As such, its assembly poses a formidable task for the ER quality control machinery. Although a large body of literature exists on the assembly and quality control of the ¿¿TCR, these efforts have focused primarily on the unusual transmembrane domains of the individual chains. These possess charged residues that, when unpaired, accelerate degradation of the ¿¿TCR chains and are believed to drive assembly. However, the basis of this presumed "integral membrane quality control" step has not been elucidated. Furthermore, very little attention has been directed to possible roles for the lumenal portions of this receptor, which are likely to be the regions scrutinized by the known quality control machinery of the ER. To remedy this deficiency, we propose to combine biophysical and cell based studies to obtain high resolution structural and kinetic data on the folding and assembly of the ¿¿TCR that can be correlated with checkpoints in the cell. Our preliminary data obtained from these approaches have already revealed two unanticipated features of the TCR ¿-chain. We find that its constant domain is unstructured in the absence of association with the ¿- chain and that its transmembrane region is not integrated into the ER membrane when expressed alone. These two features are very likely to provide checkpoints in the quality control of receptor assembly. These preliminary insights will be expanded in order to obtain an integrated view of the ER mechanisms that aid and monitor TCR biosynthesis allowing only properly assembled receptors to be expressed on the cell surface.

描述（由申请人提供）：T细胞受体对于适应性免疫系统的主要功能至关重要，并且是最复杂的细胞表面受体之一。它由八条多肽链组成，必须以正确的化学计量在 ER 中组装，才能发挥其重要功能。因此，其组装对于 ER 质量控制机器来说是一项艰巨的任务。尽管存在大量关于TCR的组装和质量控制的文献，但这些努力主要集中在单个链的不寻常的跨膜域上。它们具有带电残基，当不配对时，会加速TCR链的降解，并被认为可以驱动组装。然而，这种假定的“整体膜质量控制”步骤的基础尚未阐明。此外，很少有人关注该受体的管腔部分的可能作用，这些区域可能是由已知的内质网质量控制机制仔细检查的区域。为了弥补这一缺陷，我们建议将生物物理学和基于细胞的研究结合起来，以获得可与细胞中的检查点相关的“TCR”折叠和组装的高分辨率结构和动力学数据。我们从这些方法获得的初步数据已经揭示了 TCR 链的两个意想不到的特征。我们发现其恒定结构域在不与 β 链关联的情况下是非结构化的，并且其跨膜区在单独表达时不会整合到 ER 膜中。这两个特征很可能为受体组装的质量控制提供检查点。这些初步见解将得到扩展，以便获得 ER 机制的综合视图，帮助和监测 TCR 生物合成，只允许正确组装的受体在细胞表面表达。