Functional Studies of Calmyrin

描述（由申请人提供）：本研究的目的是了解calmyrin的功能，calmyrin是一种豆豆醇化的钙结合蛋白，可与阿尔茨海默病相关蛋白早老素-2 （PS2）相互作用。我们的初步数据表明calmyrin是一种钙传感器：钙结合触发蛋白质的大构象变化。我们认为钙诱导的钙myrin构象的改变对于促进其在细胞内的动态靶向和与蛋白质（如PS2）的结合是重要的。我们发现过表达calmyrin可诱导钙失调和细胞凋亡。然而，calmyrin诱导钙失调和细胞凋亡的机制尚不清楚。钙调磷酸酶2B （calcineurin）的调控亚基calcineurin B与calcineurin B同源性最高。在酵母双杂交筛选中，我们分离出一种假定为丝氨酸磷酸酶的calmitase。我们的初步结果表明，钙调磷酸酶可能类似于钙调磷酸酶，它可能是由钙调磷酸酶调节的催化磷酸酶成分。根据这一假设，我们发现calmyrin以钙依赖的方式结合calmitase， calmyrin和calmitase的共同表达导致calmitase在细胞核中的定位发生巨大变化，并刺激NFATc-GFP报告基因的核输入。我们还发现转基因表达一种msv驱动的calmyrin结构导致小鼠脱发和过早死亡。我们认为calmyrin是一种重要的蛋白质，并建议采用多管齐下的方法来表征calmyrin和calmitase的功能。我们提出了四个特定的目标：目标1，确定calmyrin在细胞功能中的作用。目的2，表征和确定calmitase的功能。目的3：研究MSV-calmyrin转基因小鼠的特性。目标4，在特定的器官和组织中产生calmyrin基因被破坏的小鼠。从拟议的研究中获得的结果将使人们更好地了解细胞和生物体中的calmyrin，并最终了解其在健康和疾病中的作用

DESCRIPTION (provided by applicant): The goal of this research is to understand the function of calmyrin, a myristoylated calcium-binding protein that interacts with the Alzheimer's disease related protein, presenilin-2 (PS2). Our preliminary data suggest calmyrin is a calcium sensor: calcium binding triggers a large conformational change in the protein. We believe that the calcium-induced change in calmyrin conformation is important for facilitating its dynamic intracellular targeting and binding to proteins, such as PS2. We found overexpression of calmyrin induces calcium dysregulation and apoptosis. However, the mechanism(s) by which calmyrin induces calcium dysregulation and apoptosis is not known. Calmyrin shares highest homology with calcineurin B, the regulatory subunit of protein phosphatase 2B (calcineurin). In a yeast two-hybrid screen, we isolated calmitase, a putative serine phosphatase. Our preliminary results suggest that calmitase might be analogous to calcineurin, in that it could be the catalytic phosphatase component that is regulated by calmyrin. In accord with this hypothesis, we found calmyrin binds calmitase in a calcium-dependent manner and that co-expression of calmyrin and calmitase results in a dramatic alteration in calmitase localization in the nucleus and stimulates nuclear import of an NFATc-GFP reporter. We also found that transgenic expression of an MSV-driven calmyrin construct causes alopecia and premature death in mice. We believe that calmyrin is an important protein and propose to use a multi-pronged approach to characterize calmyrin and calmitase functions. We propose four specific aims: Aim 1, to determine the role of calmyrin in cell function. Aim 2, to characterize and determine the function of calmitase. Aim 3, to characterize MSV-calmyrin transgenic mice. Aim 4, to generate mice that are disrupted of the calmyrin gene in specific organs and tissues. The results obtained from the proposed research will lead to a better understanding of calmyrin in cells and organisms, and ultimately, its role in health and disease