Structure of calcyclin binding protein-S100A6 complex

说明(申请人提供)S100蛋白构成EF-Hand钙结合蛋白的一个主要亚家族，其特征是在各种疾病状态下具有特定细胞类型的表达和异常高的丰度，包括关节炎、癌症、囊性纤维化和艾滋病。这些蛋白与其他EF-Hand蛋白的不同之处在于它们具有独特的N-末端钙结合位点和与锌的高亲和力。S100似乎参与了不同于典型的EF-Hand钙传感器控制的钙信号通路(例如。钙调蛋白和肌钙蛋白C)，但也具有钙信号转导以外的其他功能。关于S100蛋白的结构和其他生物物理性质已经积累了大量的数据。然而，由于几乎所有这些研究都是在没有细胞靶点的情况下对载脂蛋白和/或钙负载状态进行的，因此在知识方面存在一个关键的差距。本申请中提出的研究集中在S100蛋白质结构生物学最重要的悬而未决的问题上：结合细胞靶标对S100蛋白质的结构、动力学和离子亲和力有何影响？将利用一种结合了生化和结构方法的多学科战略来解决这些关键问题。Chazin和Kuzicki小组之间的合作将生物物理和结构研究与波兰的生物学家的合作结合起来，后者也在努力阐明S100蛋白质的功能，以帮助确保结构结果的生物学意义。这项研究计划的长期目标是了解S100蛋白独特的细胞活性的结构基础，以便我们能够解决它们在健康和疾病中的作用。在这个方案中，我们将确定S100A6与其目标钙周期蛋白结合蛋白的复合体的结构。波兰团队将克隆、生产和鉴定这种蛋白质。美国团队将进行溶液核磁共振实验以及结构计算和分析。这项研究将主要在波兰进行，作为NIH#R01 GM62112号补助金的延伸。

DESCRIPTION (provided by applicant) S100 proteins constitute a major subfamily of EF-hand Ca2+-binding proteins that are characterized by cell type-specific expression and unusually high abundance in a variety of disease states, including arthritis, cancer, cystic fibrosis and AIDS. These proteins are distinguished from other EF-hand proteins by their unique N-terminal Ca2+ binding sites and high affinity for Zn2+. The S100s appear to take part in Ca2+ signalling pathways that are distinct from those controlled by the prototypical EF-hand Ca2+ sensors (eg. calmodulin and troponin C), but also have proposed functions other than in Ca2+ signalling. A considerable amount of data has been accumulated on the structure and other biophysical properties of S100 proteins. However, there is a critical gap in knowledge because nearly all of these studies have been carried out on either apo and/or Ca2+-loaded states in the absence of cellular targets. The research proposed in this application is focused on the most important outstanding question regarding S100 protein structural biology: What are the effects of binding to cellular targets on S100 protein structure, dynamics and ion affinity? A multi-disciplinary strategy that incorporates biochemical and structural approaches will be utilized to address these critical questions. The collaboration between the Chazin and Kuznicki groups couples biophysical and structural research to those of biologists in Poland who are also working to elucidate S100 protein function, to help ensure the biological significance of the structural results. The broad, long-term objectives of this research program are to understand the structural basis for the distinct cellular activities of S100 proteins, so that we may address their roles in health and disease. In this proposal, we will determine the structure of the complex of S100A6 with its target calcyclin binding protein. The Polish team will clone, produce and characterize the protein. The US team will carry out solution NMR experiments and structure calculations and analysis. This research will be done primarily in Poland as an extension of NIH grant # R01 GM62112.