Role of iRhoms and ADAM17 in EGFR and TNFalpha signaling

iRhoms 和 ADAM17 在 EGFR 和 TNFα 信号转导中的作用

• 批准号: 10316173
• 负责人: Carl Peter Blobel
• 金额: $ 41.14万
• 依托单位: HOSPITAL FOR SPECIAL SURGERY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10316173
• 关键词: Anabolism; Autoimmune Diseases; Binding; Biochemical; Biological; Biological Assay; Cell surface; Cells; Complex; Cytoplasmic Tail; Development; Disease; Disintegrins; Endoplasmic Reticulum; Epidermal Growth Factor Receptor; Genetic; Goals; Immune; Inflammatory; Ligands; Malignant Neoplasms; Membrane; Metalloproteases; Molecular; Mus; Myeloid Cells; Pathology; Pathway interactions; Property; Proteins; Receptor Protein-Tyrosine Kinases; Regulation; Role; Septic Shock; Signal Pathway; Signal Transduction; Signaling Molecule; Site; Structure; Transmembrane Domain; base; cancer therapy; cytokine; in vivo; intestinal barrier; mutant; novel; skin barrier

ADAM17 (a disintegrin and metalloprotease 17) is a cell surface metalloprotease with vital roles in regulating the EGF-receptor as well as TNFa signaling. EGFR-ligands and TNFa are made as membrane- anchored precursors that must be proteolytically released or “shed” to activate the soluble signaling molecule. Mice lacking ADAM17 resemble mice lacking the EGFR, providing genetic evidence for the essential role of ADAM17 in EGFR signaling. Moreover, inactivation of ADAM17 in myeloid cells protects from septic shock in mice, which is caused by the release of soluble TNFa from myeloid cells. These functions establish ADAM17 as an important potential target for the treatment of EGFR- and TNFa-dependent pathologies such as cancer and autoimmune diseases. ADAM17 activity is highly regulated and is influenced by numerous signaling pathways. How these pathways functionally intersect with ADAM17 and how ADAM17 is activated are key questions that are the main focus of my lab. Previously, we had found that ADAM17 is regulated by its transmembrane domain (TMD), which ultimately led us to identify the seven-membrane spanning iRhoms1 and 2 (iR1, iR2) as novel regulators of ADAM17. We showed that iR2 controls the function of ADAM17 in immune cells and that inactivation of iR1 and iR2 abolishes all functions of ADAM17 in mice, thereby providing biochemical, cell biological and genetic evidence that iR1 and iR2 are the long sought-after regulators of ADAM17. The main goals of the current proposal are to understand how iR1 and 2 integrate, interpret and execute the signals that drive the activation of the ADAM17/EGFR- and ADAM17/TNFa signaling pathway. In the next 5 years, we will explore the biosynthesis and regulation of the iRhom/ADAM17 complexes and how they target substrates in a selective manner. We know that the cytoplasmic domain of ADAM17 is required to stabilize the protein, most likely so that it can assembly with an iRhom in the endoplasmic reticulum (ER). We would like to identify the factors that stabilize ADAM17 and the sites in ADAM17 and the iRhoms that promote their interaction. Once the iRhoms have assembled with ADAM17, they move to the cell surface. We will use mutant iRhoms that are retained in the ER to identify binding partners that regulate their export from the ER. We will also explore how the substrate selectivity of iRhoms is determined at the molecular level. Finally, ADAM17 is unique in that it responds rapidly to several different signaling pathways, a property that is thought to be essential for its role in skin and intestinal barrier protection. We will study the molecular details of the on/off switch for ADAM17, and generate mice that express a constitutively active ADAM17 that cannot be activated to determine how important this unique property of ADAM17 is in vivo. Together, our planned studies will resolve the most pressing current questions regarding the regulation of ADAM17, a major cellular sheddase that is critical for TNFa and EGFR signaling and a target for treatment of cancer and autoimmune diseases, by its recently discovered upstream regulators iR1 and iR2.

ADAM17（一种解整合素和金属蛋白酶 17）是一种细胞表面金属蛋白酶，在 调节 EGF 受体以及 TNFa 信号转导 EGFR 配体和 TNFa 被制成膜- 必须通过蛋白水解释放或“脱落”以激活可溶性信号分子的锚定前体。 缺乏 ADAM17 的小鼠与缺乏 EGFR 的小鼠相似，为 EGFR 的重要作用提供了遗传证据 ADAM17 在 EGFR 信号转导中的作用 此外，髓系细胞中 ADAM17 的失活可防止败血性休克。 小鼠中，这是由骨髓细胞释放可溶性 TNFa 引起的。这些功能建立了 ADAM17。 作为治疗 EGFR 和 TNFa 依赖性病变（例如癌症）的重要潜在靶标 ADAM17 活性受到多种信号传导的高度调控并受到影响。 这些途径如何与 ADAM17 功能交叉以及 ADAM17 如何被激活是关键。 此前，我们发现 ADAM17 受到其调控。 跨膜结构域（TMD），最终使我们识别出跨越 iRhoms1 和 2 (iR1, iR2) 作为 ADAM17 的新型调节剂 我们证明 iR2 控制 ADAM17 在免疫中的功能。 细胞中 iR1 和 iR2 的失活会消除小鼠中 ADAM17 的所有功能，从而提供 生化、细胞生物学和遗传学证据表明 iR1 和 iR2 是长期以来备受追捧的调节因子 ADAM17. 当前提案的主要目标是了解 iR1 和 2 如何集成、解释和 执行驱动 ADAM17/EGFR- 和 ADAM17/TNFa 信号通路激活的信号。 未来5年，我们将探索iRhom/ADAM17复合物的生物合成和调控， 它们如何以选择性方式靶向底物 我们知道 ADAM17 的细胞质结构域是 需要稳定蛋白质，很可能这样它就可以在内质网中与 iRhom 组装 (ER)。我们希望确定稳定 ADAM17 以及 ADAM17 和 iRhoms 中的位点的因素。 一旦 iRhoms 与 ADAM17 组装，它们就会移动到细​​胞表面。 我们将使用保留在 ER 中的突变 iRhoms 来识别调节其输出的结合伙伴 我们还将探讨如何在分子水平上确定 iRhoms 的底物选择性。 最后，ADAM17 的独特之处在于它能够快速响应多种不同的信号通路，这一特性 被认为对于其在皮肤和肠道屏障保护中的作用至关重要，我们将研究其分子细节。 ADAM17 的开/关开关，并生成表达组成型活性 ADAM17 的小鼠，该 ADAM17 不能被 激活以确定 ADAM17 的这种独特特性在体内的重要性。 我们计划的研究将共同​​解决当前有关监管的最紧迫问题 ADAM17 是一种主要细胞脱落酶，对 TNFa 和 EGFR 信号转导至关重要，也是治疗 癌症和自身免疫性疾病，由其最近发现的上游调节因子 iR1 和 iR2 引起。