Trans-Golgi Network Remodeling by Microbial Factors

项目总结 真核生物的反式高尔基体网络(TGN)作为主要的分选机制而受到广泛的研究 隔室和新合成蛋白质的末端加工和修饰中心。而当 TGN以其与恒定流量相关的动态性质而闻名，无论其结构是否可以 微生物-真核生物相互作用的改变和随后的后果仍然难以捉摸，直到 最近。我们之前的研究发现，多种微生物因素(如细菌抗生素黑素) 和Graicidin)能够诱导TGN分解成囊泡。这些分散的TGN囊泡 然后作为组装和激活NLRP3炎症体的信号平台。NLRP3 途径诱导促炎细胞因子，其过度激活与广泛的 多种人类疾病，包括自身免疫性疾病、癌症、神经变性和新陈代谢 精神错乱。重要的是，这些刺激并不影响密切相关的顺行和内侧高尔基体，这表明它 是一个受到严格监管的重组活动，专门针对TGN。解剖了详细的细胞和 分子基础一直具有挑战性，因为这些刺激要么是小分子，要么是非核糖体 不是由基因编码的多肽。最近，我们发现了两组微生物因子，即毛孔- 从细菌中形成毒素，从病毒中形成病毒孢子蛋白，作为高度特异性的TGN分散刺激。这种蛋白质 这些刺激的性质使我们能够很容易地追踪它们的易位，并从基因上操纵它们 研究其对TGN重塑的影响。此外，我们发现有证据表明，TGN重塑不仅 对炎症信号很重要，但也会导致糖基化改变。这一Mira的最终目标是 R35的建议是利用这些蛋白质微生物因子作为工具来研究其详细的机制和功能 TGN的重塑。我们将探讨三个主要问题：(1)哪些区域/主题对 这些刺激来重塑TGN？我们对新的TGN分散肽基序的鉴定将极大地 便于将来在微生物和真核生物中筛选和鉴定其他TGN分散配体 有机体。(2)什么是真核因子(如TGN定位的GTP酶和Golgin家族蛋白)？ 在TGN重塑中，它们在其他真核生物如酵母中的功能是如何保守的？(3)如何 TGN重塑是否影响真核细胞的各种过程，包括炎症信号和 蛋白质修饰？我们提议的研究将有助于填补有关机制和 TGN重塑的功能，以及为创新的合理设计提供宝贵的见解 治疗，以缓解广泛的人类健康问题。

PROJECT SUMMARY Eukaryotic trans-Golgi network (TGN) has been extensively studied for its role as the major sorting compartment and the center for terminal processing and modifications of newly synthesized proteins. While the TGN is known for its dynamic nature associated with the constant flux of traffic, whether its structures can be altered in microbe-eukaryote interactions and the subsequent consequences have remained elusive until recently. Our previous study has discovered that multiple microbial factors (e.g., bacterial antibiotics nigericin and gramicidin) are able to induce the disassembly of the TGN into vesicles. These dispersed TGN vesicles then serve as a signaling platform for the assembly and activation of the NLRP3 inflammasome. NLRP3 pathway induces proinflammatory cytokines, and its hyperactivation has been closely associated with a wide variety of human diseases, including autoimmune diseases, cancers, neurodegeneration, and metabolic disorders. Importantly, these stimuli do not affect the closely associated cis- and medial-Golgi, indicating that it is a tightly regulated reorganization event specifically targeting the TGN. Dissection of the detailed cellular and molecular basis has been challenging because these stimuli are either small molecules or nonribosomal peptides not encoded by genes. Recently, we have discovered two groups of microbial factors, i.e., pore- forming toxins from bacteria and viroporins from viruses, as highly specific TGN-dispersing stimuli. The protein nature of these stimuli has allowed us to easily track their translocation and genetically manipulate them to study the effects on TGN remodeling. In addition, we found evidence that TGN remodeling is not only important for inflammatory signaling, but also results in altered glycosylations. The ultimate goal of this MIRA R35 proposal is to use these protein microbial factors as tools to study the detailed mechanisms and functions of TGN remodeling. We will pursue three major questions: (1) What are the regions/motifs that are critical for these stimuli to remodel the TGN? Our identification of novel TGN dispersion peptide motifs will greatly facilitate future screening and identification of other TGN dispersion ligands in both microbes and eukaryotic organisms. (2) What eukaryotic factors (e.g., TGN-localized GTPases and golgin family proteins) are involved in TGN remodeling, and how conserved are their functions in other eukaryotic species such as yeast? (3) How does TGN remodeling affect various eukaryotic cellular processes, including inflammatory signaling and proteins modifications? Our proposed studies will help fill a critical knowledge gap on the mechanisms and functions of TGN remodeling, as well as providing invaluable insights into the rational design of innovative therapeutics to mitigate a wide range of human health problems.