Fine-Tuning the Notch Signaling Pathway via O-Glucosylation

通过 O-葡萄糖基化微调 Notch 信号通路

基本信息

批准号：
8037758
负责人：
Hamed Jafar-Nejad
金额：
$ 26.46万
依托单位：
UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-04-01 至 2012-02-29
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8037758
关键词：
Adult Affect Alleles Animals Biochemical Biological Biological Assay Biological Process Biology Cardiovascular Diseases Cell Culture Techniques Cell Death Cell Differentiation process Cell Line Cell Maintenance Cell Proliferation Cell surface Cells Cellular biology Chemicals Defect Dementia Demyelinations Development Disease Dominant Genetic Conditions Drosophila genus Endoplasmic Reticulum Enzymes Epidermal Growth Factor Exhibits Extracellular Domain Eye Gene Transfer Techniques Genes Genetic Genetic Screening Glucose Glucosyltransferase Goals Grant Hair Cells Heart High temperature of physical object Human Injury Integrase Kidney Labyrinth Ligands Light Liver Malignant Neoplasms Mediating Methods Modification Muscle Mutagenesis Mutation Neurites Notch Signaling Pathway Outcome Pathogenesis Pathway interactions Pattern Phenotype Post-Translational Protein Processing Process Proteins Public Health Regulation Role Screening procedure Signal Transduction Site Skeleton Stem cells Temperature Testing Therapeutic Transgenic Organisms Tumor Suppressor Genes base cell fate specification cerebrovascular developmental disease fly gene function glycosylation human disease in vivo loss of function nervous system disorder notch protein novel null mutation presenilin protein protein interaction regenerative research and development skeletal disorder stem cell division sugar trafficking

项目摘要

DESCRIPTION (provided by applicant): Notch signaling is an evolutionarily conserved pathway that regulates processes as diverse as cell fate specification, stem cell proliferation and maintenance, cell death, compartment boundary formation and cortical neurite outgrowth. Also, aberrant Notch signaling is involved in a variety of human diseases including cerebrovascular dementia, cancer and developmental disorders affecting liver, heart, skeleton, eye, and kidney. Although a lot of effort has been devoted to understanding the function of the genes with all-or-none effects in this pathway, much less is known about how animals fine-tune signaling, an issue of potentially high relevance to human disease pathogenesis and therapeutics. The focus of this proposal is on the characterization of a novel Notch regulator rumi, which we have identified in an unbiased chemical mutagenesis screen in Drosophila. Unlike other regulators of Notch, null mutations of rumi exhibit a dramatically temperature-sensitive Notch loss-of- function phenotype. In vivo analysis indicates that Rumi functions in the endoplasmic reticulum of the signal-receiving cell and is required upstream of the Presenilin function. Biochemical and cell culture studies have shown that Rumi is able to add glucose residues to specific EGF repeats of Notch. In this proposal we will use a combination of genetic, cell biological and biochemical analyses to identify the mechanism underlying the temperature-sensitivity and reversibility of the rumi phenotype, to test the hypothesis that Rumi regulates Notch signaling via altering the glycosylation pattern of the Notch protein in vivo, and to identify other Notch "fine-tuning" genes by screening for genetic modifiers of rumi. Rumi is a highly conserved protein, as transgenic expression of human Rumi rescues rumi mutations in flies. Moreover, vertebrate studies have shown that manipulation of the Notch pathway can be of potential therapeutic value in several disease contexts, including inner ear hair cell loss, muscle injury and demyelination. Therefore, our hope is that by shedding light on the interface of cell biology and development, the research proposed in this grant will not only unravel some of the strategies used by animals to regulate signaling, but might also contribute to efforts aimed at altering the outcome of human diseases. Since to our knowledge Rumi is the first protein O- glucosyltransferase identified in animals, our studies will also establish a framework for understanding the role of this highly conserved modification in metazoan biology. PUBLIC HEALTH REVELANCE: Alterations in Notch signaling causes a variety of human diseases including cancer, cardiovascular, skeletal and neurological disorders. Notch signaling is also involved in the regulation of stem cell division and differentiation. In this proposal we will characterize how addition of glucose residues to the Notch protein fine-tunes signaling mediated by this important pathway.

描述（由申请人提供）：Notch信号传导是一种进化保守的途径，该途径调节与细胞命运规格，干细胞增殖和维持，细胞死亡，隔室边界形成和皮质神经突生长一样多样化。同样，异常的缺口信号传导参与了各种人类疾病，包括影响肝脏，心脏，骨骼，眼睛和肾脏的脑血管痴呆，癌症和发育障碍。尽管已经大量努力用于理解该途径中具有全有效作用的基因的功能，但对于动物如何微调信号传导，这是与人类疾病发病机理和治疗学有潜在高度相关性的问题的知之甚少。该提议的重点在于一种新型凹口鲁米的表征，我们已经在果蝇中无偏的化学诱变筛选中鉴定出来。与其他Notch的调节剂不同，Rumi的无效突变表现出极大的温度敏感性功能丧失表型。体内分析表明，Rumi在信号接种细胞的内质网中起作用，并且需要Presenilin功能的上游。生化和细胞培养研究表明，Rumi能够在Notch的特定EGF重复序列中添加葡萄糖残基。 In this proposal we will use a combination of genetic, cell biological and biochemical analyses to identify the mechanism underlying the temperature-sensitivity and reversibility of the rumi phenotype, to test the hypothesis that Rumi regulates Notch signaling via altering the glycosylation pattern of the Notch protein in vivo, and to identify other Notch "fine-tuning" genes by screening for genetic modifiers of rumi. Rumi是一种高度保守的蛋白质，因为人类Rumi的转基因表达在苍蝇中挽救了Rumi突变。此外，脊椎动物的研究表明，在几种疾病情况下，对Notch途径的操纵可能具有潜在的治疗价值，包括内耳毛细胞的损失，肌肉损伤和脱髓鞘。因此，我们的希望是，通过阐明细胞生物学和发育的界面，本赠款中提出的研究不仅会揭示动物用于调节信号传导的某些策略，而且还可能有助于改变人类疾病结果的努力。由于据我们所知，Rumi是在动物中鉴定出的第一个蛋白O-葡萄糖基转移酶，因此我们的研究还将建立一个框架，以了解这种高度保守的修饰在后生动物生物学中的作用。公共卫生启示：Notch信号的改变会导致各种人类疾病，包括癌症，心血管，骨骼和神经系统疾病。 Notch信号传导还参与了干细胞分裂和分化的调节。在此提案中，我们将表征如何在该重要途径介导的Notch蛋白微调信号传导中添加葡萄糖残基。