Structure of calcyclin binding protein-S100A6 complex

S100蛋白是EF-hand Ca2+结合蛋白的一个主要亚家族，其特征是细胞类型特异性表达，在多种疾病状态（包括关节炎、癌症、囊性纤维化和艾滋病）中具有异常高的丰度。这些蛋白与其他EF-hand蛋白的区别在于它们独特的n端Ca2+结合位点和对Zn2+的高亲和力。s100似乎参与Ca2+信号通路，这与典型的EF-hand Ca2+传感器控制的信号通路不同。钙调蛋白和肌钙蛋白C)，但也提出了Ca2+信号传导以外的功能。关于S100蛋白的结构和其他生物物理性质已经积累了相当多的数据。然而，存在一个关键的知识缺口，因为几乎所有这些研究都是在没有细胞靶标的情况下进行的载脂蛋白和/或Ca2+负载状态。本申请中提出的研究重点是S100蛋白结构生物学中最重要的突出问题：与细胞靶点结合对S100蛋白结构、动力学和离子亲和力的影响是什么？结合生化和结构方法的多学科策略将用于解决这些关键问题。Chazin和Kuznicki小组之间的合作将生物物理和结构研究与波兰生物学家的研究结合起来，后者也致力于阐明S100蛋白的功能，以帮助确保结构结果的生物学意义。该研究计划的长远目标是了解S100蛋白不同细胞活动的结构基础，以便我们能够解决它们在健康和疾病中的作用。在本提案中，我们将确定S100A6与其靶钙调素结合蛋白复合物的结构。波兰团队将克隆、生产并鉴定这种蛋白质。美国团队将进行溶液核磁共振实验和结构计算分析。这项研究将主要在波兰进行，作为NIH拨款# R01 GM62112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.