Biochemistry, biology and diversity of Fic domains

生物化学、生物学和 Fic 领域的多样性

• 批准号: 10550154
• 负责人: Kim Orth
• 金额: $ 36.9万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-02-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10550154
• 关键词: Active Sites; Adenosine Monophosphate; Aging; Binding Sites; Biochemistry; Biological; Biological Process; Biology; Cell physiology; Cells; Chemistry; Disease; Drosophila genus; Endoplasmic Reticulum; Enzymes; Genetic; Goals; Growth; Health; Homeostasis; In Vitro; Inflammation; Mammals; Mediating; Modification; Molecular; Molecular Chaperones; Molecular Target; Neurodegenerative Disorders; Neuronal Plasticity; Neurons; Orphan; Play; Proliferating; Proteins; Regulation; Role; Sodium Chloride; Stress; Threonine; Transgenic Mice; cancer cell; endoplasmic reticulum stress; in vivo; interest; response

Project Summary A variety of cellular processes are commonly subverted to encourage the proliferation of cancer cells, one of which is the unfolded protein response (UPR) that occurs in the endoplasmic reticulum (ER). Importantly, there is also a strong connection between UPR and inflammation or neuronal health. Many neurodegenerative diseases and diseases of aging have connections to the UPR. We have recently discovered a new form of BiP regulation, AMPylation by the protein Fic. We observe that Fic adds an adenosine monophosphate (AMP) molecule to a threonine near the ATP binding site of BiP during normal growth conditions. This modification rapidly is removed by the same enzyme Fic under multiple ER stress-inducing conditions. We recently have shown that the regulation of BiP by Fic is essential for maintaining neuronal homeostasis. Since our discovery of Fic domains that mediate AMPylation, other diverse activities performed by bacterial Fic domains have been identified. These studies have revealed the molecular plasticity of Fic domains in its ability to utilize diverse substrates. Despite these studies, there are many different Fic proteins that remain to be characterized, both in catalytic activity, biological function, and molecular targets. We propose three projects that will further our understanding of the biology of Fic enzymes and the chemistry they use, both in vitro and in vivo. First, when the ER is stressed, Fic changes from an AMPylator to a deAMPylator, and the key to this regulation is breaking a salt bridge in Fic's active site. We want to understand the biochemistry regulating this switch. Second, our studies with Drosophila genetics show that Fic is required for neuronal plasticity. We are therefore interested in understanding what role Fic plays in mammalian biology using transgenic mice. Third, there are many different Fic proteins that remain to be characterized, both in catalytic activity, biological function, and molecular targets. We plan to investigate these orphan Fic domains and identify their biological activities and substrates.

项目概要 多种细胞过程通常被破坏以促进癌细胞的增殖， 其中之一是在内质网（ER）中发生的未折叠蛋白反应（UPR）。 重要的是，UPR 与炎症或神经元健康之间也存在密切联系。 许多神经退行性疾病和衰老疾病都与 UPR 有关。我们有 最近发现了一种新的 BiP 调节形式，即蛋白质 Fic 的 AMPylation。我们观察到 Fic 将单磷酸腺苷 (AMP) 分子添加到 BiP ATP 结合位点附近的苏氨酸上 在正常生长条件下。这种修饰很快被相同的酶 Fic 在 多种 ER 应激诱发条件。我们最近表明 Fic 对 BiP 的调节是 对于维持神经元稳态至关重要。自从我们发现可以调节的 Fic 域以来 已鉴定出细菌 Fic 结构域进行的 AMPylation 和其他多种活性。这些 研究揭示了 Fic 结构域在利用不同底物的能力方面的分子可塑性。 尽管有这些研究，仍有许多不同的 Fic 蛋白有待表征，无论是在 催化活性、生物功能和分子靶标。我们提出了三个项目，将进一步 我们对 Fic 酶的生物学及其在体外和体内使用的化学的了解。 首先，当ER受到压力时，Fic从AMPylator变为deAMPylator，而这的关键 监管正在打破 Fic 活性位点的盐桥。我们想了解生物化学 调节这个开关。其次，我们对果蝇遗传学的研究表明，Fic 是 神经元的可塑性。因此，我们有兴趣了解 Fic 在哺乳动物中扮演什么角色 使用转基因小鼠的生物学。第三，还有许多不同的 Fic 蛋白有待进一步研究。 在催化活性、生物功能和分子靶标方面均具有特征。我们计划 研究这些孤儿 Fic 结构域并确定其生物活性和底物。