The role of spatio-temporal nano-organization in regulating the specificity of JAK/STAT signaling

配体诱导的信号传递通过质膜上的特定受体是细胞在多细胞生物体中发挥其复杂作用的关键过程。虽然已经建立了不同受体类型如何介导这一过程的主要范例，但控制配体激活信号的特异性的分子和生物物理参数还远未明确。一个关键的挑战是理解所谓的信号特异性悖论，即有限的细胞内信号效应器可以控制无数的信号输出。这个跨学科和协作项目的总体目标是揭示JAK/STAT信号特异性是如何由质膜和内小体上激活的干扰素受体(IFNR)复合体的纳米区划控制的。IFNRs代表了研究这些机制复杂性的最佳范例之一，因为I型IFNAR和II型IFNGR都激活了共同的STAT1分子，但显示了不同的转录输出。Lamaze小组(P1)最近发现，IFNR内吞运输和质膜脂基纳米组织分别在I型和II型干扰素(IFN)选择性激活JAK/STAT中发挥关键作用。Piehler小组(P2)已经建立了先进的成像技术，用于使用单分子定位成像技术来监测IFNR组装和时空动力学。质膜纳米区划为肌动蛋白和脂基区域的作用将通过生物化学和遗传修饰来探索。具体地说，我们的目标是确定IFNGR定位到脂筏的特定功能可能与特定的脂类和半乳糖凝集素相互作用有关。我们将通过质谱学(P1)确定新的相互作用伙伴，这将通过功能表面微图案(P2)在活细胞中得到验证。这些相互作用伙伴在IFNR信号转导中的作用将通过生物物理(P2)和功能研究(P1)进一步阐明。根据这些研究获得的详细机制图，我们将尝试系统地交换I型和II型干扰素受体之间的功能模块，以验证它们在特定细胞环境中的功能相关性(P1)。

Ligand-induced signal propagation through specific receptors in the plasma membrane is a key process for the cell in order to fulfill its complex role within multicellular organisms. While principal paradigms of how this process is mediated by different receptor types have been established, the molecular and biophysical parameters, which control the specificity of signal activation by the ligand, are far from being clear. A key challenge is to understand the so-called paradox of signaling specificity where a limited set of intracellular signaling effectors can control myriads of signaling outputs. The overall aim of this interdisciplinary and collaborative project is to uncover how the specificity of JAK/STAT signaling specificity is controlled by the nano-compartmentalization of the activated interferon-receptor (IFNR) complexes at the plasma membrane and in endosomes. IFNRs represent one of the best paradigms to investigate the complexity of these mechanisms since both type I IFNAR and type II IFNGR activate a common STAT1 molecule but display a distinct transcriptional output. The Lamaze group (P1) has recently shown that IFNR endocytic trafficking and lipid-based nano-organization at the plasma membrane play a key role in the selectivity of JAK/STAT activation by type I and type II interferons (IFNs), respectively. The Piehler group (P2) has established advanced imaging techniques for monitoring IFNR assembly and spatiotemporal dynamics using single molecule localization imaging techniques. The role of plasma membrane nano-compartmentalization into actin and lipid-based domains will be explored by using biochemical and genetic modifications. Specifically, we aim to identify how specific features of IFNGR localization into lipid rafts, are probably related to specific lipid and galectin interactions. We will identify new interaction partners by mass spectrometry (P1), which will be validated in living cells by functional surface micropatterning (P2). The role of these interaction partners in IFNR signaling will be further elucidated by biophysical (P2) and functional studies (P1). Based on the detailed mechanistic picture obtained from these studies, we will attempt to systematically swap functional modules between the type I and type II IFN receptors in order to validate their functional relevance in a specific cellular context (P1).