Structural insights into the unique activation mechanisms of receptor tyrosine kinases

受体酪氨酸激酶独特激活机制的结构见解

• 批准号: 10600031
• 负责人: Xiaochen Bai
• 金额: $ 40.63万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10600031
• 关键词: Affect; Agonist; Agrin; Binding; Biochemical; Biological Assay; Biological Process; Cell Surface Receptors; Cell membrane; Cell physiology; Cell surface; Cells; Complex; Cryoelectron Microscopy; Cytoplasm; Data; Development; Dimerization; Environment; Exhibits; Family; Goals; HGF gene; Heparin; In Vitro; Inflammation; KDR gene; Laboratories; Learning; Length; Ligand Binding; Ligands; Link; Lipids; Liposomes; Maintenance; Malignant Neoplasms; Membrane; Membrane Lipids; Modeling; Molecular; Molecular Conformation; Muscle; Muscle Cells; Mutagenesis; Neuromuscular Junction; Normal Cell; PDGFRB gene; Phosphatidylserines; Phosphorylation; Phosphotransferases; Physiological; Play; Protein Isoforms; Proteins; Protomer; Receptor Activation; Receptor Protein-Tyrosine Kinases; Regulation; Resolution; Role; Sampling; Signal Transduction; Structure; TAC1 gene; Tertiary Protein Structure; adaptive immunity; antagonist; cell motility; crosslink; dimer; extracellular; human disease; improved; insight; member; nanodisk; receptor; reconstitution; recruit

Receptor tyrosine kinases (RTKs) play key roles in regulating normal cellular processes and are linked to many human diseases. Each RTK protomer contains an extracellular region that binds activating ligands, a single transmembrane helix, and an intracellular region that contains the kinase domain necessary for intracellular signaling. For many RTKs, their cognate ligands form stable homodimers, and the binding of dimeric ligand to the extracellular region of RTK drives receptor dimerization, which then brings two intracellular kinases in close proximity, enabling their autophosphorylation. The phosphorylated kinases can further recruit effector proteins, and thereby triggering downstream signaling cascade. This “ligand-induced-dimerization” is the long-standing model for the activation of RTKs, and has been well characterized by extensive structural and functional studies. Nevertheless, it has been suggested that several members in RTK family use unique activation mechanisms. For instance, the MuSK receptor alone cannot directly bind to and be activated by its ligand Agrin, but requiring assistance of the co-receptor Lrp4 on the muscle cell surface for activation. In addition, the activation of TAM receptor requires not only the binding of its ligands, but also the involvement of phosphatidylserine lipid (PtdSer) from plasma membrane. Furthermore, our preliminary structure results showed that, different to all other RTKs, one HGF molecular can simultaneously engages two c-MET receptors by utilizing two distinct interfaces; therefore, a single HGF is sufficient for the activation of c-MET receptor, which represents another paradigm in activation mechanisms of RTK. The goal of this project is to study the structures and functions of several special RTKs, including MuSK, TAM and c-MET receptors, whose activation mechanism are still poorly understood. Solving the high-resolution structures of different unique members of RTK family in the ligand-bound active state will explain the specific features that differentiate these receptors from other RTKs, and reveal the common mechanism and diversification in the activation of RTK. Aim 1 will be focused on the functional and structural analyses of MuSK receptor complex. This study will reveal the detailed binding mode between MuSK, Lrp4 and Agrin, and explain why co-receptor Lrp4 is critical for the activation of MuSK. Aim 2 will be focused on biochemical and structural analyses of TAM receptor in the membrane associated functional state. The result from this study will allow us to explain the functional importance of PtdSer in TAM activation. Aim 3 will be focused on the structural determination of c-MET receptor in the HGF bound active state to understand why single HGF molecular is sufficient for c-MET activation.

受体酪氨酸激酶（RTK）在控制正常的细胞过程中起关键作用，并与许多 人类疾病。每个RTK蛋白都包含一个结合激活配体的细胞外区域，一个 跨膜螺旋和一个细胞内区域，该区域包含细胞内所需的激酶结构域 信号。对于许多RTK，它们的同源配体形成稳定的同型二聚体，并结合二聚体配体与 RTK的细胞外区域驱动接收器二聚化，然后将两个细胞内激酶在近距离 接近，使其自磷酸化。磷酸化激酶可以进一步募集效应蛋白， 从而触发下游信号级联。这种“配体诱导的二分化”是长期存在的 激活RTK的模型，并以广泛的结构和功能为特征 研究。尽管如此，有人建议RTK家庭中的几个成员使用独特的激活 机制。例如，麝香受体无法直接与其配体结合并激活 Agrin，但需要在肌肉细胞表面的共受体LRP4帮助以进行激活。另外， TAM接收器的激活不仅需要其配体的结合，还需要参与 来自质膜的磷脂酰丝氨酸脂质（PTDSER）。此外，我们的初步结构结果 表明，与所有其他RTK不同，一个HGF分子可以简单地接合两个C-MET接收器 通过使用两个不同的接口；因此，单个HGF足以激活C-MET接收器， 它代表了RTK激活机制的另一个范式。该项目的目的是研究 几种特殊RTK的结构和功能，包括Musk，Tam和C-Met接收器，谁 激活机制仍然很少了解。解决不同独特的高分辨率结构 配体结合活性状态的RTK家族的成员将解释区分这些特征的特定功能 来自其他RTK的受体，并揭示了RTK激活中的共同机制和多样化。 AIM 1将集中于Musk接收器复合物的功能和结构分析。这项研究会 揭示Musk，LRP4和Agrin之间的详细结合模式，并解释为什么共受体LRP4至关重要 激活麝香。 AIM 2将集中在TAM受体的生化和结构分析上 膜相关的功能状态。这项研究的结果将使我们能够解释功能 PTDSER在TAM激活中的重要性。 AIM 3将集中于C-MET的结构确定 HGF结合活性状态的受体，了解为什么单个HGF分子足以用于C-MET 激活。

项目成果

Oncogenic RAS Drives Resistance to Pemigatinib in Cholangiocarcinoma Harboring a FGFR2 Delins Disrupting Ligand Binding.

致癌 RAS 驱动含有 FGFR2 Delins 的胆管癌对 Pemigatinib 产生耐药性，破坏配体结合。

• DOI: 10.1200/po.22.00340
• 发表时间: 2023
• 期刊: JCO precision oncology
• 影响因子: 4.6
• 作者: Lim,Mir;Lynch,PatrickT;Bai,Xiaochen;Hsiehchen,David
• 通讯作者: Hsiehchen,David

A structural model of a Ras-Raf signalosome.

• DOI: 10.1038/s41594-021-00667-6
• 发表时间: 2021-10
• 期刊: Nature structural & molecular biology
• 影响因子: 16.8
• 作者: Mysore VP;Zhou ZW;Ambrogio C;Li L;Kapp JN;Lu C;Wang Q;Tucker MR;Okoro JJ;Nagy-Davidescu G;Bai X;Plückthun A;Jänne PA;Westover KD;Shan Y;Shaw DE
• 通讯作者: Shaw DE