MEGAKARYOCYTE AND PLATELET PROTEOGLYCANS

这是竞争性续签提案的第三次修订。 这项建议的长期目标是理解 丝氨酸的结构、功能及其表达调控 蛋白多糖。已知它是由巨核细胞和 髓系细胞。它包含在血小板α颗粒中， 肥大细胞分泌颗粒，在刺激下释放。 它是由淋巴细胞结构性分泌并上调的 在激活过程中。这个实验室最近发现 分子也在人内皮细胞、小鼠血管内皮细胞中表达 卵黄囊和胚胎干细胞中。丝氨酸甘氨酸与 几种基质分子和细胞因子，并可能参与 调节细胞的激活和黏附。丝氨酸甘氨酸可能是 对早期胎儿发育很重要。糖胺多聚糖 (GAG)链的长度、数量和组成在细胞之间不同 类型和是绑定的重要决定因素 由不同细胞组成的分子的特性。这个 提案将尝试建立体内的功能角色 丝氨酸氨基葡萄糖。在具体目标1中，调查人员将 不同来源丝氨酸的GAG链含量的表征 细胞来源，以确定其结合倾向 不同的分子。在具体目标2中，他们将执行 丝氨酸甘氨酸的功能分析 来自不同来源的天然和修饰丝氨酸结合 基质分子和细胞因子。因此，这些实验可能 阐明其作用机制的结构基础 丝氨酸蛋白多糖家族，并可能导致 治疗剂的发展。他们会做好准备 胚胎干细胞中该基因的纯合子敲除 监测对拟胚体形成的影响和 造血细胞。在特定的目标3中，他们将本地化 胎儿和成人组织中丝氨酸蛋白和信使核糖核酸的原位表达 确定体内合成和沉积的部位。这将是 使他们能够更好地了解这种分子的功能。 在特定目标4中，他们将准备启动子构建 小鼠血清蛋白及其在几种细胞类型中的比较调节 与他们关于人类基因的细胞特异性表达的数据。 已被发现在体外具有活性的启动子构建 将被用来产生转基因小鼠以分析 体内启动子调控的细胞特异性。进一步研究 可以为细胞特定的基因敲除生成独特的方法 基因在小鼠体内建立该分子的功能 不同的细胞。

This is the third revision of a competitive renewal proposal. The long-range goal of this proposal is to understand the structure, function and regulation of expression of the serglycin proteoglycan. It is known to be made by megakaryocytes and myeloid cells. It is contained in platelet alpha granules and mast cell secretory granules, and is released upon stimulation. It is constitutively secreted from lymphocytes and upregulated during activation. This laboratory has recently found that the molecule is also expressed in human endothelial cells, in murine yolk sac, and in embryonic stem cells. Serglycin binds to several matrix molecules and cytokines, and could be involved in modulating cell activation and adhesion. Serglycin may be important for early fetal development. The glycosaminoglycan (GAG) chain length, number and composition differ amongst cell types and are important determinants of the binding characteristics of molecules made by different cells. The proposal will attempt to establish the in vivo functional roles of serglycin. In Specific Aim 1, the investigators will characterize the GAG chain content of serglycins from different cell sources in order to determine their propensity for binding to different molecules. In specific Aim 2, they will perform functional analyses of serglycin by analyzing the ability of native and modified serglycins from different sources to bind to matrix molecules and cytokines. These experiments may thus elucidate the structural basis for the mechanism of action of the serglycin family of proteoglycans, and possibly lead to the development of the therapeutic agents. They will prepare homozygous knockouts of the gene in embryonic stem cells and monitor the effects on formation of embryoid bodies and hematopoietic cells. In Specific Aim 3, they will localize serglycin protein and mRNA in fetal and adult tissues in situ to determine sites of synthesis and deposition in vivo. This will enable them to better understand the function f this molecule. In Specific Aim 4, they will prepare promoter constructs of murine serglycin and compare regulation in several cell types with their data on cell-specific expression of the human gene. Promoter construct which have been found to be active in vitro will be used to generate transgenic mice in order to analyze the cell specificity of promoter regulation in vivo. Further studies could generate unique methods for cell-specific knockouts of the gene in mice to establish the function of this molecule in different cells.