Investigating of the Function of Copine A in Dictyostelium

描述(申请人提供)：Copine是一种高度保守的钙依赖膜结合蛋白，存在于包括人类在内的许多不同的真核生物中。对人类铜绿素的研究表明，铜绿素可能通过与目标蛋白结合，然后将这些目标蛋白招募到特定的膜上来响应钙浓度的增加，从而在信号通路中发挥作用。这项建议描述了以发育中的网柄网柄菌为模型来具体检验上述假设的实验。网生鞭毛虫可以作为单细胞阿米巴虫独立生活，但当被置于饥饿条件下时，单个阿米巴虫相互发出信号，首先聚集，然后分化成细胞，形成多细胞子实体。这一简单的发育程序不仅被广泛用于研究发育，还被广泛用于研究几种基本的细胞过程，包括趋化作用介导的细胞运动、信号转导、程序性细胞死亡细胞和细胞分化。以往的研究表明，网柄苔藓中的一种Copine蛋白CpnA是正常发育所必需的，其他几种Copine基因的发育表达模式表明，它们也可能是发育的调节因子。具体目标1中概述的实验旨在进一步确定CpnA在发育中的作用，并研究另外两种Copine蛋白的功能。这些实验将使我们能够确定Copine发挥作用的发育和细胞过程；然而，它们用来实现这些功能的确切机制将需要像第二个特定目标中提出的那样的生化研究。在特定目标2中概述的实验旨在确定DictyostelialCopins的目标蛋白，以探索Copins作为伴侣或在信号通路中作用的招募蛋白的机制作用。人类基因组有8个Copine基因，其中大部分在骨髓细胞和血白细胞中表达；因此，Copine可能参与这些细胞内的细胞信号通路。增加我们对铜绿素如何发挥作用的科学知识可以使我们更好地了解人类血液和免疫细胞相关疾病。与公共健康相关：该提案概述了研究一种名为Copins的新型蛋白质家族的功能的实验。铜绿素被认为在细胞信号通路中发挥作用，但其确切功能尚不清楚。人类基因组有8个Copine基因，大多数存在于骨髓细胞和血白细胞中。增加我们对铜绿素如何发挥作用的科学知识可能会使我们更好地了解人类血液和免疫细胞相关疾病。

DESCRIPTION (provided by applicant): Copines are highly conserved calcium-dependent membrane-binding proteins found in numerous diverse eukaryotic organisms, including humans. Studies with human copines suggest that copines may act in signaling pathways by binding to target proteins and then recruiting these target proteins to a particular membrane in response to an increase in calcium concentration. This proposal describes experiments to specifically test the above hypothesis using developing Dictyostelium as a model. Dictyostelium can live independently as single celled amoebae, but when placed in starvation conditions, single amoeba signal each other to first aggregate and then differentiate into cells that form a multicellular fruiting body. This simple developmental program in Dictyostelium is widely used to study not only development, but also several basic cell processes including chemotaxis-mediated cell motility, signal transduction, programmed cell death cell, and cell differentiation. Previous studies show that one of the copine proteins in Dictyostelium, CpnA, is required for normal development and the developmental expression patterns of several of the other copine genes suggest they too may be regulators of development. The experiments outlined in specific aim 1 are designed to further characterize the role of CpnA in development as well as investigate the function of two other copine proteins. These experiments will allow us to determine the developmental and cellular processes in which copines function; however, the exact mechanism that they use to carry these functions will require biochemical studies like the ones proposed in the second specific aim. Experiments outlined in specific aim 2 are designed to identify the target proteins of the Dictyostelium copines to explore the mechanistic role of copines as chaperone or recruiting proteins functioning in signaling pathways. The human genome has eight copine genes and most of them are expressed in bone marrow cells and blood leukocytes; therefore, copines are potentially involved in cell signaling pathways within these cells. Increasing our scientific knowledge of how copines function could lead to a better understanding of human blood and immune cell-related diseases. PUBLIC HEALTH RELEVANCE: The proposal outlines experiments to investigate the functions of a novel family of proteins called copines. Copines are hypothesized to have roles in cell signaling pathways, but their exact functions are unknown. The human genome has eight copine genes and most are found in bone marrow cells and blood leukocytes. Increasing our scientific knowledge of how copines function could potentially lead to a better understanding of human blood and immune cell related diseases.