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: 10334464
• 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/10334464
• 关键词: Active Sites; Adenosine Monophosphate; Aging; Binding Sites; Biochemistry; Biological; Biological Process; Biology; Cell physiology; Cells; Chemistry; Drosophila genus; Endoplasmic Reticulum; Enzymes; GRP78 gene; Genetic; Goals; Growth; Health; Homeostasis; In Vitro; Inflammation; Mammals; Mediating; Modification; Molecular; Molecular Chaperones; Molecular Target; Neurodegenerative Disorders; Neuronal Plasticity; Neurons; Orphan; Play; 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.

项目摘要 通常颠覆过多种细胞过程，以鼓励癌细胞的扩散， 其中之一是内质网（ER）中发生的展开的蛋白质反应（UPR）。 重要的是，UPR与炎症或神经元健康之间也有很强的联系。 许多神经退行性疾病和衰老疾病与UPR有联系。我们有 最近发现了一种新形式的BIP调节形式，即蛋白质FIC的两臂化。我们观察到那个 在BIP的ATP结合位点附近，将腺苷一磷酸（AMP）分子添加到苏氨酸 在正常生长条件下。通过相同的酶FIC迅速去除此修饰 多个ER诱导应力条件。我们最近表明，FIC对BIP的调节是 维持神经元稳态至关重要。由于我们发现了介导的FIC领域 已确定了两组贝酰化，其他不同的活性已经鉴定出细菌FIC结构域进行。这些 研究揭示了FIC结构域利用不同底物的分子可塑性。 尽管进行了这些研究，但仍有许多不同的FIC蛋白尚待表征，都在 催化活性，生物功能和分子靶标。我们提出了三个将进一步的项目 我们对FIC酶的生物学及其在体外和体内使用的化学作用的理解。 首先，当ER受到压力时，FIC会从双甲基转变为脱臂，这是此关键 法规正在打破FIC活跃部位的盐桥。我们想了解生物化学 调节此开关。其次，我们对果蝇遗传学的研究表明，FIC是必需的 神经元可塑性。因此，我们有兴趣了解FIC在哺乳动物中的作用 使用转基因小鼠的生物学。第三，仍然有许多不同的FIC蛋白 在催化活性，生物学功能和分子靶标中都表征了。我们计划 研究这些孤儿域，并确定其生物学活性和底物。