Lipid Modification of Extracellular Signaling Ligands

细胞外信号配体的脂质修饰

• 批准号: 7217731
• 负责人: JOSEFA M STEINHAUER
• 金额: $ 4.68万
• 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/7217731
• 关键词: Acylation; Acyltransferase; Amides; Animal Model; Attenuated; 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

DESCRIPTION (provided by applicant): 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 lipidation or of mutating their candidate acyltransferases will 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 attenuate the spread of cancer.

描述(申请人提供)：细胞间通讯对于多细胞生物体的发育、生长和功能是必不可少的，这种通讯主要通过生长因子和其他细胞外配体进行。尽管许多工作都集中在了解细胞如何从细胞外信号中接收和传递信息，但对于配体如何在细胞外空间中导航仍有许多未知之处。最近发现了几种重要的细胞外配体，包括主要的果蝇表皮生长因子受体配体Spitz。由于棕榈酰化发生在来自不同途径的几个不相关的信号分子上，似乎其他这样的分子也可能是棕榈酰化的，对不同途径的研究可能会产生这种修饰的共同机制功能。为了进一步了解Spitz棕榈酰化的功能，我们将在体内测试几种突变的Spitz蛋白。具体地说，为了确定Spitz酰化的唯一目的是否是膜结合，通过不可切割的跨膜结构域人工连接膜的非棕榈酰化的Spitz构建体将被检测。一种非棕榈酰化的糖基磷脂酰肌醇连接的Spitz也将被检测，以确定Spitz与脂筏的联系是否对功能重要。为了研究其他细胞外配体是否被酰化，将检测果蝇基因组中未描述的假定的酰基转移酶的功能。已知的三个被酰化的细胞外信号分子，即Spitz、Hedgehog和Wingless，是膜结合O-酰基转移酶家族的相关酰基转移酶的底物。果蝇体内存在7种推测属于该家族的酶，其中3种尚未被鉴定。编码这些蛋白质的基因将被突变，并进行表型测试，这表明它们在其他细胞外信号配体的棕榈酸化过程中发挥了作用。不同类别的果蝇信号配体也将通过细胞培养和生化实验直接测试脂肪作用，以表征这些分子的疏水性。对于被脂化的配体，将在体内测试干扰其脂化或突变其候选酰基转移酶的影响。细胞间通讯缺陷被认为与许多癌症有关。了解调节这种交流的分子的生化性质将有助于我们对这些疾病的理解。这些研究还可能揭示治疗药物的新途径，这些药物可以阻止细胞间信号传递，从而减弱癌症的扩散。