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: 6520212
• 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/6520212
• 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（HSPGS）由附着在糖胺聚糖（GAG）链的蛋白质核心组成，与许多细胞过程有关，例如细胞粘附，运动，增殖和差异。尽管HSPG代表了细胞表面分子的主要类别之一，但其实际作用和特异性知之甚少。最近，HSPG在发育过程和特定信号传导途径中的关键作用通过鉴定HSPG生物合成中的许多突变来说明。在果蝇中，产生或修饰插孔链的酶突变表现出使人联想到无翅（WG），成纤维细胞生长因子（FGF）和/或刺猬（HH）活性的表型。有趣的是，特定的信号通路似乎被与GAG链形成的某些酶以及编码蛋白质核的基因中的突变所破坏。我们的假设是，HSPG在配体/受体相互作用以及分布在额外的细胞信号中起特定的作用。为了深入了解信号过程中这些分子的功能和特异性，我们将分析与GAG链生物合成有关的酶的作用，以及由Syndecan和Syndecan和Glypicans（Dally和K-Glypican）编码的蛋白质核心。使用遗传，细胞生物学和生化研究，我们提出：确定与HH信号传导有关的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信号传导的特异性的基础；阐明Dally如何与WG及其受体DFZ2合作；证明syndecan编码涉及FGF信号的HSPG；阐明Ally如何与WG及其受体DFZ2合作；证明syndecan编码涉及FGF信号的HSPG；并表征合成HSPG的其他酶。总之，我们对HSPG的分析将阐明HSPG在许多信号通路中的功能，这些信号传导途径在发育过程中起主要作用。因为这些途径也与各种疾病阶段有关；例如，肿瘤发生，我们的研究可能导致新的方法来调节这些信号传导途径的活性。