ROLES OF HEPARAN SULFATE PROTEOGLYCANS IN SIGNALING

硫酸乙酰肝素蛋白聚糖在信号传导中的作用

• 批准号: 6363347
• 负责人: NORBERT PERRIMON
• 金额: $ 24.77万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-03-01 至 2004-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6363347
• 关键词: Drosophilidae; SDS polyacrylamide gel electrophoresis; alleles; biological signal transduction; developmental genetics; fibroblast growth factor; gene expression; gene interaction; gene mutation; glycosyltransferase; high performance liquid chromatography; immunoprecipitation; mucopolysaccharides; polymerase chain reaction; protein biosynthesis; protein protein interaction; protein signal sequence; protein structure function; proteoglycan; syndecan; western blottings

Heparan sulfate proteoglycans (HSPGs), which are composed of a protein core attached to Glycosaminoglycan (GAG) chains, have been implicated in a number of cellular processes such as cell adhesion, motility, proliferation, and differentiation. Although HSPGs represent one of the major classes of cell surface molecules, their actual roles and specificities are poorly understood. Recently, the critical roles of HSPGs in developmental processes and specific signaling pathways have been illustrated by the identification of a number of mutations in genes involved in HSPG biosynthesis. In Drosophila, mutations in enzymes that generate or modify the GAG chains, exhibit phenotypes reminiscent of loss of Wingless (Wg), Fibroblast Growth Factor (FGF) and/or Hedgehog (Hh) activities. Intriguingly, specific signaling pathways appear to be disrupted by mutations in some of the enzymes involved in GAG chain formation, as well as in genes that encode the protein cores. Our hypothesis is that HSPGs play specific roles in ligand/receptor interactions as well as distribution on extra cellular signals. To gain insight into the function and specificity of these molecules during signaling, we will analyze the roles of both the enzymes involved in biosynthesis of the GAG chains, as well as the protein cores encoded by Syndecan and Glypicans (Dally and K-Glypican). Using genetic, cell biological and biochemical studies, we propose to: identify the protein core of the HSPG involved in Hh signaling; elucidate of the HSPG involved in Hh signaling, determine the basis of the specificity of Tout velu/Ext glycosyltransferase to Hh signaling; elucidate how Dally co- operates with Wg and its receptor, Dfz2; demonstrate that Syndecan encodes the HSPG involved in FGF signaling; elucidate how ally co- operates with Wg and its receptor, Dfz2; demonstrate that Syndecan encodes the HSPG involved in FGF signaling; and characterize additional enzymes that synthesize HSPGs. Altogether, our analyses of HSPGs will elucidate the function of HSPGs in a number of signaling pathways that play major roles in developmental processes. Because these pathways have also been implicated in various disease stages; e.g., oncogenesis, our studies may lead to novel ways to modulate specifically the activity of these signaling pathways.

硫酸乙酰肝素蛋白聚糖 (HSPG) 由附着于糖胺聚糖 (GAG) 链的蛋白质核心组成，与细胞粘附、运动、增殖和分化等许多细胞过程有关。尽管 HSPG 是细胞表面分子的主要类别之一，但人们对它们的实际作用和特异性知之甚少。最近，通过鉴定参与 HSPG 生物合成的基因中的许多突变，说明了 HSPG 在发育过程和特定信号传导途径中的关键作用。在果蝇中，产生或修饰 GAG 链的酶突变会表现出类似 Wingless (Wg)、成纤维细胞生长因子 (FGF) 和/或 Hedgehog (Hh) 活性丧失的表型。有趣的是，某些参与 GAG 链形成的酶以及编码蛋白质核心的基因的突变似乎破坏了特定的信号传导途径。我们的假设是 HSPG 在配体/受体相互作用以及细胞外信号分布中发挥特定作用。为了深入了解这些分子在信号传导过程中的功能和特异性，我们将分析参与 GAG 链生物合成的酶以及 Syndecan 和 Glypicans（Dally 和 K-Glypican）编码的蛋白质核心的作用。通过遗传、细胞生物学和生化研究，我们建议： 鉴定参与 Hh 信号传导的 HSPG 的蛋白质核心；阐明参与 Hh 信号传导的 HSPG，确定 Tout velu/Ext 糖基转移酶对 Hh 信号传导的特异性基础；阐明 Dally 如何与 Wg 及其受体 Dfz2 合作；证明 Syndecan 编码参与 FGF 信号传导的 HSPG；阐明 ally 如何与 Wg 及其受体 Dfz2 合作；证明 Syndecan 编码参与 FGF 信号传导的 HSPG；并表征合成 HSPG 的其他酶。总而言之，我们对 HSPG 的分析将阐明 HSPG 在许多在发育过程中发挥重要作用的信号通路中的功能。因为这些途径也与不同的疾病阶段有关；例如，肿瘤发生，我们的研究可能会带来特异性调节这些信号通路活性的新方法。