Novel mechanisms of TCR quality control

TCR质量控制的新机制

基本信息

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
项目类别：
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

项目摘要

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，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，尽管有大量关于 ER 的组装和质量控制的文献，但它的组装对 ER 质量控制机器提出了艰巨的任务。 ¿ TCR，这些努力主要集中在单个链的不寻常跨膜结构域上，这些结构域具有带电残基，当未配对时，会加速 ¿ ¿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腔部分的可能作用。为了弥补这一缺陷，我们建议将生物物理和细胞研究结合起来，以获得有关 ¿ 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 的两个意想不到的特征 ¿我们发现它的恒定域在没有与 ¿ 关联的情况下是非结构化的。 - 链并且其跨膜区域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，以便获得对受体组装的综合看法。 ER 机制帮助和监测 TCR 生物合成，仅允许正确组装的受体在细胞表面表达。