Structural Basis of Z-disc Protein/Protein Networks and Functional Implications

巨丝蛋白titin在锚定、组装和维持肌蛋白z盘相互作用体的整体结构中起着核心作用。在这里，我们想通过一种综合的方法来探索完整的titin Z-disc titin相互作用组，旨在进行结构表征（我们的关键能力）和功能表征（与P1， P3, P8）。P7（电子断层扫描）提供的技术将使我们能够将高分辨率数据整合到完整的肌肉z盘结构图像中。在第一个资助期内，我们建议重点研究两个关键的z盘丝组合，titin/α- actitin（带P6）和titin/obscurin。对于第一个项目，我们的主要目标是解开α-肌动蛋白z桥与titin z盘丝的分子基础和化学计量学。第二个项目将建立由暗蛋白介导的肌聚体z盘相互作用组与肌聚体外结构连接的分子基础，并重建发生在肌聚体z盘中重要的gtpase介导的信号通路。同时（与P4），我们将使用蛋白质组学方法寻找新的titin-配体相互作用。我们还为结构生物学导向的合作提供独特的基础设施（P2, P10）。

The giant filament protein titin is central in anchoring, assembling and maintaining the overall architecture of the sarcomeric Z-disc interactome. Here we would like to explore the complete titin Z-disc titin interactome by an integrated approach aiming for structural characterization (our key competence) and functional characterization (with P1, P3, P8). The technologies provided by P7 (electron tomography) will allow us to fit our high-resolution data into integrated images of the complete sarcomeric Z-disc architecture. During the first funding period, we propose to focus on two key Z-disc filament assemblies, titin/α-actinin (with P6) and titin/obscurin. For the first project, our key aim is to unravel the molecular basis and stoichiometry of the α-actinin Z-bridges in relation to the titin Z-disc filament. The second project will allow establishing the molecular basis of an obscurin-mediated connection of the sarcomeric Z-disc interactome to extra-sarcomeric structures and reconstituting important GTPase-mediated signaling pathways that take place in the sarcomeric Z-disc. In parallel (with P4), we will search for novel titin-ligand interactions, using proteomics approaches. We also offer our unique infrastructures for structural biology-oriented collaborations (P2, P10).