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

巨丝蛋白Titin在锚定、组装和维持肌节Z-Disk相互作用体的整体结构中起着中心作用。在这里，我们希望通过一种综合的方法来探索完整的titin Z-Disk titin交互作用组，旨在进行结构表征(我们的关键能力)和功能表征(包括P1、P3、P8)。P7(电子断层扫描)提供的技术将使我们能够将我们的高分辨率数据整合到完整的肌节Z盘结构的图像中。在第一个资助期，我们建议专注于两个关键的Z-Disc细丝组件，Titin/α-Actinin(与P6一起)和Titin/Oblcurin。对于第一个项目，我们的主要目标是揭开α-肌动蛋白Z-桥与Titin Z-Disk细丝相关的分子基础和化学计量比。第二个项目将允许建立肌瘤Z-Disc相互作用体与肌瘤外结构之间的暗黑蛋白介导的连接的分子基础，并重建发生在肌瘤Z-Disk中的重要的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肌动蛋白-配体相互作用。我们还为面向结构生物学的合作提供我们独特的基础设施(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).