Defining the role of NC1 domain assembly in collagen biosynthesis and collagen associated disorders

项目总结/摘要 胶原蛋白是细胞外基质和基底膜的重要组成部分，在那里它们用于 支持组织完整性、介导细胞迁移和组织信号传导。胶原蛋白具有三个结构域： C-末端三聚化结构域（CTD/NC 1）、胶原结构域和7S N-末端结构域。胶原 在ER中经历折叠，然后三聚化和胶原三螺旋形成，然后分泌到 细胞外环境NC 1结构域的三聚化是胶原蛋白折叠的第一步， 用于形成胶原三螺旋。胶原蛋白的突变会导致严重的疾病，如骨生成 不完美症，Alport病和脑小血管病，损害骨骼，肾脏的完整性 大脑和眼睛的血管。尽管胶原蛋白中的许多致病突变 虽然已经确定，但对发病机制的认识仍然不完全。目标 这一建议的目的是了解扰动初始三聚化如何影响成熟， 胶原IV的生物合成。在我的第一个目标中，我将开发新的基于细胞的测定来量化NC 1的作用。 结构域扰动对胶原组装的影响。具体来说，我开发了一种裂解荧光素酶测定法， NC 1结构域相互作用的孤立，并已开始量化的致病性突变的影响。此外，本发明还 我将开发互补的细胞系，表达全长胶原蛋白IV，包括最有趣的突变体 在分裂荧光素酶测定中鉴定的，以更好地理解这些扰动的功能后果。 在我的第二个目标中，我在NC 1界面设计了点突变，并确定了那些增加或减少NC 1表达的突变。 降低三聚体稳定性。令人兴奋的是，其中一个突变显著增加了NC 1的关联， 分泌物总之，这些研究将揭示胶原相关疾病的机制，并提出方法， 绕过他们。主要的创新是尖端计算方法的应用， 设计点突变来探测关于胶原蛋白组装和稳定性的特定问题。我们共同期待 这些研究为治疗胶原蛋白相关疾病提供了新的途径。最后这些 实验是一个令人兴奋的培训机会，为我提供了跨学科的指导研究经验。 学科的，转化的研究

PROJECT SUMMARY/ABSTRACT Collagens are essential components of the extra-cellular matrix and basement membranes, where they serve to bolster tissue integrity, mediate cell migration, and organize signaling. Collagen proteins have three domains: the C-terminal trimerization domain (CTD/NC1), the collagen domain and the 7S N-terminal domain. Collagens undergo folding followed by trimerization and collagen triple helix formation in the ER prior to secretion to the extra-cellular environment. Trimerization of the NC1 domain is the first step in collagen folding and is required for formation of the collagen triple helix. Mutations in collagens result in severe diseases, such as Osteogenesis Imperfecta, Alport’s Disease and Cerebral Small Vessel Disease which impair the integrity of bones, kidneys and blood vessels in the brain and eye respectively. Although many disease-causing mutations in collagens have been identified, there still is an incomplete understanding of the mechanisms of pathogenesis. The goal of this proposal is to understand how perturbing the initial trimerization effects the maturation and biosynthesis of collagen IV. In my first aim, I will develop new cell-based assays to quantify the effect of NC1 domain perturbation on collagen assembly. Specifically, I have developed a split luciferase assay that measures NC1 domain interactions in isolation and have begun to quantify the effect of pathogenic mutations. Additionally, I will develop complementary cell lines that express full-length collagen IV, including the most interesting mutants identified in the split luciferase assays, to better understand the functional consequences of these perturbations. In my second aim, I have designed point mutations at the NC1 interface, and identified those that increase or decrease trimer stability. Excitingly, one of these mutations significantly increased NC1 association and secretion. Together, these studies will reveal the mechanisms of collagen-associated disease and suggest ways of circumventing them. The major innovation is the application of cutting-edge computational approaches to design point mutations that probe specific questions about collagen assembly and stability. Together, we expect these studies to suggest new avenues for the treatment of collagen associated disorders. Finally, these experiments serve as an exciting training opportunity, providing me with a mentored research experience in inter- disciplinary, translational studies.