STRUCTURE-INFORMED STUDIES OF THE EXTRACELLULAR REGION OF THE HUMAN NOTCH RECEPTOR IN HEALTH & DISEASE

健康人Notch受体细胞外区域的结构知情研究

• 批准号: MR/V008935/1
• 负责人: Penny Handford
• 金额: $ 62.25万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FV008935%2F1
• 关键词: STRUCTURE; INFORMED; STUDIES; EXTRACELLULAR; REGION

The Notch pathway is an essential signal transduction system which regulates crucial decisions in cell biology. These are vital for embryonic development and for the maintenance of adult tissue. In its simplest form, a cell-surface expressed ligand activates the pathway by binding to the Notch receptor protein presented on the outside of a neighbouring cell. This leads to cleavage events such that the intracellular portion of the receptor is released and travels to the nucleus where it forms a complex with other proteins to activate specific genes responsible for regulating cell behaviour. Abnormal loss or gain of Notch activity is associated with many human developmental disorders, adult onset diseases and cancers, making it a key target for therapeutic intervention. Despite extensive study of the downstream consequences of activation, many aspects of the early events leading to Notch cleavage and generation of the signal remain unclear. This is because we lack understanding of the overall shape of Notch and the way in which it can interact with its ligands. Because it is such a large protein of unknown flexibility, with a fibrous rather than globular organisation, it is not technically feasible to study Notch in its intact, full-length state. Instead, due to its modular construction it can be divided into different regions based on functional importance. In previous work, we have established a structural model for the EGF4-13 polypeptide which contains a previously unrecognized region of flexibility between EGF9 and EGF10. We now wish to extend our structural and functional studies to EGF20-27 and the domains (EGF14-20) that link this to the ligand-binding region. We are keen to understand whether domains within EGF20-27 which incorporate a region known as Abruptex (Ax) can interact intra or intermolecularly with the ligand-binding region (LBR).This will enable us to understand the overall shape of the extracellular domain of Notch from EGF4 to EGF27, to identify regions that are rigid and those that are flexible, to understand the significance of the Ax/LBR interaction for structure, function and regulation of Notch activity at the cell surface. Fundamental understanding of how the Notch signal is generated should allow us to develop reagents to manipulate Notch activity and facilitate advances in many aspects of cell biology, including stem cell biology. In addition, since dysfunction of the pathway results in many inherited and acquired forms of disease, such as cancer, these reagents are likely to have therapeutic potential.

Notch信号通路是一个重要的信号转导系统，调节细胞生物学中的关键决定。这些对胚胎发育和维持成年组织至关重要。在其最简单的形式中，细胞表面表达的配体通过与邻近细胞外部存在的Notch受体蛋白结合来激活该途径。这导致裂解事件，使得受体的细胞内部分被释放并行进到细胞核，在那里它与其他蛋白质形成复合物以激活负责调节细胞行为的特定基因。Notch活性的异常丧失或获得与许多人类发育障碍、成人发病疾病和癌症相关，使其成为治疗干预的关键靶标。尽管对激活的下游后果进行了广泛的研究，但导致Notch切割和信号产生的早期事件的许多方面仍然不清楚。这是因为我们对Notch的整体形状以及它与配体相互作用的方式缺乏了解。由于它是一种未知柔性的大蛋白质，具有纤维状而非球状组织，因此在其完整的全长状态下研究Notch在技术上是不可行的。相反，由于其模块化结构，它可以根据功能重要性划分为不同的区域。在以前的工作中，我们已经建立了一个结构模型的EGF 4 -13多肽，其中包含一个以前未识别的区域之间的灵活性EGF 9和EGF 10。我们现在希望将我们的结构和功能研究扩展到EGF 20 -27和将其连接到配体结合区的结构域（EGF 14 -20）。我们非常想知道EGF 20 -27中包含Abruptex（Ax）区域的结构域是否可以与配体结合区（LBR）分子内或分子间相互作用。这将使我们能够了解Notch从EGF 4到EGF 27的细胞外结构域的整体形状，以识别刚性区域和柔性区域，理解Ax/LBR相互作用对细胞表面Notch活性的结构、功能和调节的重要性。对Notch信号如何产生的基本理解应该使我们能够开发试剂来操纵Notch活性，并促进细胞生物学（包括干细胞生物学）许多方面的进展。此外，由于该途径的功能障碍会导致许多遗传性和获得性疾病，例如癌症，因此这些试剂可能具有治疗潜力。