Lipid Modification of Extracellular Signaling Ligands

细胞外信号配体的脂质修饰

• 批准号: 7361377
• 负责人: JOSEFA M STEINHAUER
• 金额: $ 4.96万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7361377
• 关键词: Acylation; Acyltransferase; Amides; Animal Model; Base Sequence; Binding; Biochemical; Biological Assay; Bone Morphogenetic Proteins; Cell membrane; Cells; Class; Communication; Computers; Cultured Cells; Data; Defect; Disease; Drosophila genome; Drosophila genus; Drosophila melanogaster; Drosophila spi protein; Enzymes; Epidermal Growth Factor Receptor; Erinaceidae; Extracellular Space; Family; Family member; Fatty Acids; Fibroblast Growth Factor; Genes; Genetic; Genetic Screening; Genome; Glycosylphosphatidylinositols; Goals; Growth Factor; Growth and Development function; Homologous Gene; Hydrophobicity; Janus kinase; Ligands; Link; Lipids; Malignant Neoplasms; Mammals; Mediating; Membrane; Membrane Microdomains; Modeling; Modification; Mutate; Mutation; N-terminal; Nature; Object Attachment; Organism; Palmitates; Palmitic Acids; Pathway interactions; Phenotype; Platelet-Derived Growth Factor; Porcupines; Prevalence; Protein Family; Proteins; Purpose; Recycling; Role; STAT protein; Sequence Analysis; Signal Pathway; Signal Transduction; Signaling Molecule; Somatomedins; Standards of Weights and Measures; Sulfhydryl Compounds; System; Testing; Therapeutic Agents; Training; Transferase; Transmembrane Domain; Vascular Endothelial Growth Factors; Work; adduct; extracellular; in vivo; intercellular communication; intracellular protein transport; long chain fatty acid; mutant; palmitoylation; protein transport; research study; tool; trafficking

Intercellular communication is essential for the development, growth, and function of multicellular organisms, and this communication occurs predominantly via growth factors and other extracellular ligands. Although much work has focused on understanding how cells receive and transduce information from extracellular signals, much remains unknown about how ligands navigate the extracellular space. Several prominent extracellular ligands recently have been found to carry fatty acid attachments, including the primary Drosophila Epidermal Growth Factor Receptor ligand, Spitz. Because palmitoylation has been shown to occur on several unrelated signaling molecules from disparate pathways, it seems likely that other such molecules may also be palmitoylated and that a common mechanistic function for this modification may emerge from the study of different pathways. In order to further understand the function of Spitz palmitoylation, several mutant Spitz proteins will be tested in vivo. Specifically, an unpalmitoylated Spitz construct that is artificially membrane-tethered via an uncleavable transmembrane domain will be assayed in order to determine whether the sole purpose of Spitz acylation is membrane association. An unpalmitoylated glycosylphosphatidylinositol-linked Spitz also will be assayed to determine whether Spitz association with lipid rafts is important for function. To investigate whether other extracellular ligands are acylated, the function of uncharacterized putative acyltransferases in the Drosophila genome will be examined. The three extracellular signaling molecules that are known to be acylated, namely Spitz, Hedgehog, and Wingless, are substrates for related acyltransferase enzymes of the membrane bound O- acyl transferase family. Seven putative enzymes of this family exist in Drosophila, of which three have not yet been characterized. The genes encoding these proteins will be mutated and tested for phenotypes suggesting a role in palmitoylation of other extracellular signaling ligands. Drosophila signaling ligands of various classes also will be tested directly for lipidation using cell culture and biochemical experiments to characterize the hydrophobicity of these molecules. For ligands that are lipidated, the effects of perturbing their lipidationor of mutating their candidate acyltransferaseswill be assayed in vivo. Defects in intercellular communication have been implicated in many cancers. Understanding the biochemical nature of the molecules that mediate this communication will contribute to our understanding of these diseases. These studies also potentially will reveal new avenues for therapeutic agents that can block intercellular signaling and therefore attenuatethe spread of cancer.

细胞间通讯对多细胞生物的发育、生长和功能至关重要， 并且这种通讯主要通过生长因子和其它细胞外配体发生。虽然 许多工作都集中在理解细胞如何从细胞外接收和储存信息 信号，很多仍然未知的配体如何导航细胞外空间。几位著名 最近已经发现细胞外配体携带脂肪酸附着物，包括主要的 果蝇表皮生长因子受体配体，Spitz。因为棕榈酰化已经被证明 发生在几个不相关的信号分子从不同的途径，似乎很可能是其他这样的 分子也可以被棕榈酰化，并且这种修饰的常见机制功能可以 从不同途径的研究中产生。为了进一步了解斯皮茨的功能 棕榈酰化，将在体内测试几种突变Spitz蛋白。具体来说，一个未棕榈酰化的斯皮茨 将测定通过不可切割的跨膜结构域人工膜栓系的构建体 以确定Spitz酰化的唯一目的是否是膜缔合。一个 还将测定未棕榈酰化糖基磷脂酰肌醇连接的Spitz，以确定Spitz是否 与脂筏的结合对于功能是重要的。为了研究其他细胞外配体是否 酰化，果蝇基因组中未表征的假定酰基转移酶的功能将被 考察已知被酰化的三种细胞外信号分子，即Spitz， Hedgehog和Wingless是膜结合O-酰基转移酶的底物。 酰基转移酶家族这个家族的七种假定的酶存在于果蝇中，其中三种没有 还没有被定性。编码这些蛋白质的基因将被突变并进行表型测试 提示在其它细胞外信号配体的棕榈酰化中的作用。果蝇信号配体 还将使用细胞培养和生物化学实验直接测试各种类别的脂质化， 表征这些分子的疏水性。对于脂化的配体，扰动的影响 它们的脂质化或突变它们的候选酰基转移酶将在体内进行测定。细胞间缺陷 沟通与许多癌症有关。了解生物化学的本质 介导这种通讯的分子将有助于我们对这些疾病的理解。这些 研究还可能揭示阻断细胞间信号传导的治疗药物的新途径 and therefore因此attenuate衰减the spread传播of cancer癌症.