Understanding Signaling by Non-Canonical Receptor Tyrosine Kinases

了解非典型受体酪氨酸激酶的信号传导

• 批准号: 10598118
• 负责人: Mark A Lemmon
• 金额: $ 77.05万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-05-01 至 2027-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10598118
• 关键词: Acylation; Binding; Bone Diseases; Complex; Congenital Abnormality; Crystallography; Defect; Dependence; Dimerization; Disease; Extracellular Structure; Human; Insulin Receptor; Knowledge; Ligand Binding; Ligands; Malignant Neoplasms; Membrane; Methods; Modeling; Molecular Conformation; Neurodevelopmental Disorder; Phosphotransferases; Play; Property; Proteins; ROR1 gene; Receptor Protein-Tyrosine Kinases; Receptor Signaling; Regulation; Research; Resolution; Role; Signal Transduction; Signaling Molecule; Subcellular structure; Testing; Therapeutic; Tyrosine; Tyrosine Kinase Domain; WNT Signaling Pathway; beta catenin; conformational conversion; extracellular; human disease; insight; kinase inhibitor; member; novel therapeutic intervention; novel therapeutics; receptor; recruit; small molecule; therapeutic target; wound healing

The research proposed in this MIRA renewal application seeks to understand mechanisms of transmembrane signaling by members of the receptor tyrosine kinase (RTK) superfamily – and other receptor-like kinases – that do not fit the ‘rules’ that explain most RTKs. Non-canonical receptors in this group play important roles in human disease – from neurodevelopmental disorders, to bone diseases, cancers, and congenital malformations. The traditional model for RTK signaling involves ligand-induced receptor dimerization, which promotes tyrosine autophosphorylation of the receptor and recruitment of downstream signaling molecules. As we understand more about the 58 human RTKs, it has become clear that this mechanism only applies to about half of them. For example, 10% of human RTKs are linked to WNT signaling, and must function differently because their intracellular regions often have only catalytically inactive ‘pseudokinase’ domains. Still other RTKs (such as ALK) have unique extracellular regions for which ligand binding and receptor regulation are poorly understood. We have made significant progress in understanding extracellular and intracellular structures of WNT-regulated pseudokinase RTKs. Their extracellular WNT-binding modules differ significantly from their counterparts in proteins involved in ‘canonical’ WNT signaling, in ways that suggest well-defined hypotheses for how these RTKs might participate as co-receptors with Frizzled receptors in b-catenin independent WNT signaling. The intracellular pseudokinase domains of the RTKs structurally resemble the insulin receptor kinase in its ‘inactive’ conformation, and analysis of their structural dynamics suggests that they can undergo the same ‘inactive-like’ to ‘active-like’ conformational transitions seen for normal tyrosine kinase domains. Indeed, we have found that these transitions can be promoted by small molecule kinase inhibitor-like molecules, despite the fact that the isolated pseudokinase domains do not bind ATP. In the next 5-10 years of this project, we propose to test hypotheses for WNT-induced assembly of receptor complexes that incorporate pseudokinase RTKs, elucidate their specific WNT dependence and reliance on WNT acylation, gain high resolution structural views through crystallography and EM, and analyze their signaling properties. We will test hypotheses for how the pseudokinase domains contribute to signaling – either by acquiring kinase activity or by functioning as allosterically switchable interaction platforms, with precedents in other pseudokinases and in catalytically active kinases such as Aurora A. In parallel with these efforts, we will investigate new opportunities for therapeutic targeting of pseudokinase RTKs such as PTK7, ROR1, ROR2, and RYK, which have all been implicated in numerous diseases. Together, these studies will provide important new insight into signaling by receptors that do not fit normal paradigms for RTKs or WNT receptors. The new lessons should also be applicable to other classes of receptor-like kinases implicated in disease, opening new avenues for potential therapeutic inhibition.

这项MIRA更新申请中提出的研究旨在了解跨膜 受体酪氨酸激酶（RTK）超家族成员和其他受体样激酶的信号传导， 不符合解释大多数RTK的“规则”。这一组中的非典型受体在以下方面发挥重要作用： 人类疾病-从神经发育障碍，到骨骼疾病，癌症和先天性 畸形RTK信号传导的传统模型涉及配体诱导的受体二聚化， 促进受体的酪氨酸自磷酸化和下游信号分子的募集。作为 我们对58个人类RTK有了更多的了解，很明显，这种机制只适用于大约 其中一半。例如，10%的人类RTK与WNT信号有关，并且必须以不同的方式发挥作用。 因为它们的细胞内区域通常仅具有无催化活性的“假激酶”结构域。另外其他 RTK（如ALK）具有独特的细胞外区域，其配体结合和受体调节是细胞外区域的一部分。 不太了解。我们在了解细胞外和细胞内的 WNT调节的假激酶RTK的结构。它们的细胞外WNT结合模块显著不同 与参与“典型”WNT信号传导的蛋白质中的对应物不同， 关于这些RTK如何作为共同受体与卷曲受体参与b-连环蛋白的假说 独立的WNT信令。RTK的细胞内假激酶结构域在结构上类似于 胰岛素受体激酶在其“非活性”构象中，并对其结构动力学进行分析表明， 它们可以经历与正常酪氨酸相同的“非活性样”到“活性样”的构象转变 激酶结构域。事实上，我们已经发现，这些转变可以促进小分子激酶 尽管事实上分离的假激酶结构域不结合ATP。未来 5-10多年的这个项目，我们建议测试WNT诱导的受体复合物组装的假设 其结合了假激酶RTK，阐明了它们对WNT酰化的特异性依赖性和依赖性， 通过晶体学和EM获得高分辨率的结构视图，并分析其信号特性。 我们将测试假激酶结构域如何促进信号传导的假设-通过获得激酶 活动或通过作为变构可切换的相互作用平台发挥作用， 假激酶和催化活性激酶如Aurora A.与此同时，我们将 研究以假激酶RTK如PTK 7、ROR 1、ROR 2 和RYK，它们都与许多疾病有关。这些研究将提供重要的 对受体信号传导的新见解，这些受体不适合RTK或WNT受体的正常模式。新 这些经验也适用于与疾病有关的其他类型的受体样激酶， 潜在治疗抑制的途径。