Regulation of Ras in development by post-translational modification

通过翻译后修饰调控 Ras 的发育

• 批准号: 10578698
• 负责人: CATHIE M PFLEGER
• 金额: $ 33.9万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-03-13 至 2025-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10578698
• 关键词: Address; Alleles; Biochemistry; Biological; Cell Proliferation; Cell Survival; Cells; Cues; Development; Developmental Biology; Drosophila genus; Elements; Embryonic Development; Ensure; Feedback; Genetic; Genetic Complementation Test; Goals; Growth; Homeostasis; Impairment; In Vitro; Longevity; Malignant Neoplasms; Mediating; Modification; Molecular; Mutation; N-terminal; Neurofibromatosis 1; Noonan Syndrome; Output; Pathway interactions; Pattern; Phenotype; Phosphoric Monoester Hydrolases; Phosphorylation; Phosphotransferases; Post-Translational Protein Processing; Process; Proliferating; Proteins; RAS inhibition; Ras Signaling Pathway; Regulation; Research; Role; Signal Pathway; Signal Transduction; System; Testing; Therapeutic; Translating; Tumor Suppression; Tyrosine; Tyrosine Phosphorylation; Ubiquitin; Ubiquitination; Up-Regulation; Work; developmental disease; in vivo; inorganic phosphate; insight; mutant; novel; response; screening; trafficking

SUMMARY Eukaryotic signaling pathways translate external cues in specific contexts into diverse biological outputs. Proper timing and duration of a signaling response requires careful regulation of stability, trafficking, activation, and deactivation of multiple components within a network. This overall coordination can involve positive feedback circuits to amplify signaling and/or negative feedback circuits to constrain signaling. The Ras signaling pathway is crucial in development to regulate proliferation, cell survival, cell fate, and patterning. Mutations in Ras or other components of the pathway that lead to increased Ras signaling cause developmental disorderes collectively known as “Rasopathies” such as Noonan's syndrome or Neurofibromatosis Type 1 (NF1). Using Drosophila, we discovered that Rabex-5 (an E3) downregulates Ras by promoting its mono- and di-ubiquitination. Specifically, we discovered that impairing Ras ubiquitination in vivo in Drosophila led to striking effects on cell proliferation, cell survival, developmental patterning, and organismal longevity, reflecting a role for Ras ubiquitination in development, tumor suppression, and survival. The power of Drosophila genetics and the well-established paradigm of studying Ras in Drosophila make this system ideally suited to characterize this phenomenon in a multi-cellular context. We more recently discovered that Rabex-5 targeting of Ras requires an N-terminal tyrosine in Ras, Tyrosine 4 (Y4). We hypothesize that phosphorylation of this tyrosine directs targeting of Ras by Rabex-5. Our hypothesis predicts that the kinase(s) and phosphatase(s) that regulate modification of Y4 are crucial regulators of Ras signaling. The goal of our application is to elucidate the role of tyrosine phosphorylation of Ras to direct its inhibitory Rabex-5- mediated ubiquitination and maintain pathway homeostasis. Specifically, we propose to further characterize the biological role of Y4 phosphorylation in Ras ubiquitination, to identify the Ras Y4 kinase(s) and phosphatase(s), and to characterize their roles in regulating Ras in development.

概括 真核信号通路将特定环境中的外部线索转化为不同的生物输出。 信号反应的适当时机和持续时间需要仔细调节稳定性、运输、激活、 以及停用网络内的多个组件。这种整体协调可以包括积极的 用于放大信令的反馈电路和/或用于限制信令的负反馈电路。拉斯 信号通路对于调节增殖、细胞存活、细胞命运和模式的发育至关重要。 Ras 或其他通路成分的突变导致 Ras 信号传导增强 统称为“Rasopathies”的发育障碍，例如努南综合症或 1 型神经纤维瘤病 (NF1)。使用果蝇，我们发现 Rabex-5（E3）下调 Ras 通过促进其单泛素化和双泛素化。具体来说，我们发现，Ras 泛素化受损 果蝇体内对细胞增殖、细胞存活、发育模式和 机体寿命，反映了 Ras 泛素化在发育、肿瘤抑制和生存中的作用。 果蝇遗传学的力量和在果蝇中研究 Ras 的成熟范式使得这一点成为可能 该系统非常适合在多细胞环境中表征这种现象。我们最近发现 Rabex-5 靶向 Ras 需要 Ras 中的 N 末端酪氨酸，即酪氨酸 4 (Y4)。我们假设 该酪氨酸的磷酸化指导 Rabex-5 靶向 Ras。我们的假设预测 调节 Y4 修饰的激酶和磷酸酶是 Ras 信号转导的重要调节因子。目标 我们应用的目的是阐明 Ras 酪氨酸磷酸化在指导其抑制性 Rabex-5- 中的作用 介导泛素化并维持通路稳态。具体来说，我们建议进一步表征 Y4 磷酸化在 Ras 泛素化中的生物学作用，以鉴定 Ras Y4 激酶和 磷酸酶，并表征其在发育过程中调节 Ras 的作用。