Understanding Wnt signaling through Ror and Ryk family receptor tyrosine kinases

了解通过 Ror 和 Ryk 家族受体酪氨酸激酶的 Wnt 信号传导

• 批准号: 9244390
• 负责人: Mark A Lemmon
• 金额: $ 53.21万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-01 至 2017-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9244390
• 关键词: Address; Adult; Amino Acids; Apoptosis; Binding; Binding Sites; Biochemical; Biological Assay; Bone Diseases; Caenorhabditis elegans; Cell Maintenance; Cell Proliferation; Cell Surface Receptors; Cell physiology; Complex; Congenital Abnormality; Crystallization; Cysteine-Rich Domain; Data; Deuterium; Development; Diabetes Mellitus; Dimerization; Disease; Drosophila genus; Drosophila melanogaster; Embryo; Embryonic Development; Family; Family member; Gene Targeting; Generations; Genetic; Goals; Health; Heterodimerization; Homodimerization; Human; Hydrogen; In Vitro; LDL-Receptor Related Protein 1; Ligand Binding; Ligands; Malignant Neoplasms; Mass Spectrum Analysis; Mediating; Monomeric GTP-Binding Proteins; Names; Neurodevelopmental Disorder; Orphan; Play; Process; Receptor Protein-Tyrosine Kinases; Receptor Signaling; Research; Role; Ror receptor tyrosine kinase; Signal Transduction; Specificity; Stem cells; Structure; System; TCF Transcription Factor; Therapeutic; Therapeutic antibodies; Transcript; Wnt proteins; X-Ray Crystallography; Xenopus; base; biophysical analysis; extracellular; in vivo; insight; kinase inhibitor; member; migration; neural circuit; neurodevelopment; novel; novel strategies; organ regeneration; receptor; response; sex; sex determination; stoichiometry; success; tyrosine receptor

DESCRIPTION (provided by applicant): The goal of this proposal is to understand how two receptor tyrosine kinases (RTKs) with Wnt-binding domains in their extracellular regions mediate and/or contribute to Wnt signaling. Wnts are secreted ligands of approximately 330 amino acids that play key roles in embryonic development and control a spectrum of processes in the adult, ranging from organ regeneration to stem cell maintenance to neural circuit generation to sex determination. They do this by regulating many cellular processes including cell proliferation, migration, polarity, apoptosis, differentiation and survival. Not unexpectedly, therefore, aberrations in Wnt signaling are now known to be involved in many diseases, including bone diseases, cancers, diabetes, neurodevelopment disorders, and several congenital malformations. In addition to the best known Wnt receptors (the Frizzleds), two additional Wnt receptor families have been identified: the Ryk family (Ryk in humans, Derailed, Derailed-2 and Doughnut in Drosophila) and the Ror family (Ror1 and Ror2 in human, DRor and DNrk in Drosophila). Both are receptor tyrosine kinase (RTK) families - a receptor class not typically associated with Wnt signaling, but a class that has been successfully targeted therapeutically in other signaling systems with kinase inhibitors and antibody therapeutics. The extracellular regions of Ryk and Ror family RTKs contain domains typically associated with binding to Wnt ligands. Ryks contain a Wnt Inhibitory Factor-1 (WIF) domain, and Rors contain an extracellular cysteine-rich domain (CRD) that resembles the Wnt-binding CRDs in the Frizzled receptors. We propose here to investigate the signaling mechanisms of Ryk and Ror family RTKs using an array of approaches from in vivo assays in Xenopus embryos and cellular studies to biochemical, biophysical and structural approaches. Our goal is to determine whether Ryk and Ror receptors resemble other well known RTKs in their mode of signaling, or instead function as co-receptors for Wnts with Frizzleds or other molecules. In our Specific Aims, we will address the following questions: 1. how do Ryk family members recognize their Wnt ligands, and do Ryks resemble other RTKs in their response to extracellular ligand binding? 2i. Do Ror family members resemble other RTKs in responses to ligand binding, and does Wnt binding by their cysteine-rich domains (CRDs) resemble that of Frizzleds? 2ii. Do Ryks and Rors heterodimerize, and can Wnts bind simultaneously to both WIF domains and CRDs to drive co-receptor heterodimerization? These studies will provide important fundamental new insight into how these novel classes of Wnt receptors signal, which is crucial for understanding Wnt signaling specificity and teasing out its multiple roles. In addition, our findings should open potential new avenues for therapeutic inhibition - as the roles of these Wnt-binding RTKs in disease become increasingly clear.

描述（由申请人提供）：本提案的目标是了解胞外区域具有 Wnt 结合结构域的两种受体酪氨酸激酶 (RTK) 如何介导和/或促进 Wnt 信号传导。 Wnt 是由大约 330 个氨基酸组成的分泌配体，在胚胎发育中发挥关键作用，并控制成人的一系列过程，从器官再生到干细胞维持，从神经回路生成到性别决定。它们通过调节许多细胞过程来实现这一点，包括细胞增殖、迁移、极性、细胞凋亡、分化和存活。不出意料的是， 因此，现在已知 Wnt 信号传导的异常与许多疾病有关，包括骨病、癌症、糖尿病、神经发育障碍和几种先天畸形。除了最著名的 Wnt 受体（Frizzleds）之外，还鉴定了另外两个 Wnt 受体家族：Ryk 家族（人类中的 Ryk，果蝇中的 Derailed、Derailed-2 和 Donut）和 Ror 家族（人类中的 Ror1 和 Ror2，果蝇中的 DRor 和 DNrk）。两者都是受体酪氨酸激酶 (RTK) 家族，该受体类别通常与 Wnt 信号传导无关，但已通过激酶抑制剂和抗体疗法成功地在其他信号系统中进行治疗。 Ryk 和 Ror 家族 RTK 的胞外区域包含通常与 Wnt 配体结合相关的结构域。 Ryks 包含 Wnt 抑制因子 1 (WIF) 结构域，Rors 包含细胞外富含半胱氨酸结构域 (CRD)，类似于卷曲受体中的 Wnt 结合 CRD。 我们在此建议使用从非洲爪蟾胚胎体内测定和细胞研究到生物化学、生物物理和结构方法的一系列方法来研究 Ryk 和 Ror 家族 RTK 的信号传导机制。我们的目标是确定 Ryk 和 Ror 受体的信号传导模式是否与其他众所周知的 RTK 相似，或者是否充当 Wnt 与 Frizzleds 或其他分子的共受体。在我们的具体目标中，我们将解决以下问题： 1. Ryk 家族成员如何识别其 Wnt 配体，以及 Ryks 对细胞外配体结合的反应与其他 RTK 相似吗？ 2i. Ror 家族成员对配体结合的反应是否类似于其他 RTK，其富含半胱氨酸结构域 (CRD) 的 Wnt 结合是否类似于 Frizzleds？ 2ii. Ryks 和 Rors 是否异二聚化，Wnts 能否同时结合 WIF 结构域和 CRD 以驱动共受体异二聚化？这些研究将为了解这些新型 Wnt 受体如何发出信号提供重要的基本新见解，这对于理解 Wnt 信号传导特异性并梳理其多重作用至关重要。此外，随着这些 Wnt 结合 RTK 在疾病中的作用变得越来越清晰，我们的研究结果应该为治疗抑制开辟潜在的新途径。