The role of C. neoformans Hog1 and its effectors in translatome reprogramming

摘要 新生隐球菌是一种环境真菌和条件致病菌。 每年造成约181,000人死亡的免疫系统。新生葡萄球菌致病过程中的关键步骤 是对宿主的适应，这是由几个信号转导途径介导的。翻译本 重新编程，即蛋白质合成的变化，是这些信号转导途径的关键输出，这使得 C.neformans快速微调应激反应，这一过程中的缺陷与减少有关 致命性。然而，Hog1 p38 MAPK模块是一个介导这一过程的信号模块 在新生葡萄球菌中，Hog1介导重编程的机制和效应器尚不清楚。我们 建议确定Hog1激活的分子基础，并生成高通量表征 它的互动体。我们还发现，另一个翻译组调控途径，GCN2途径，是不同的 在hog1∆中调节，并旨在评估这一变化在翻译组重编程为 以及致命性。因此，我们假设Hog1通过其激酶介导了广泛的相互作用组的变化。 活性，与GCN2途径的串扰掩盖了更严重的抗逆性缺陷和 Hog1∆的毒力。我们将测试两个具体目标：(1)确定Hog1调节的机制 新生葡萄球菌的应激反应，以及(2)评估eIF2α磷酸化增加是否可以补偿 因为失去了Hog1。这个项目意义重大，因为它将阐明Hog1，Will重新编程的机制 确定可以作为目标来抑制这一过程的效应器，并将检查 有两条主要的信号通路。这项研究培训计划的总体目标是使应聘者具备 回答这些问题的必要技能，并为他们提供相关培训，以确立自己的地位 作为研究真菌发病机制和应激适应的成功的学术研究者。这些目标将是 在赞助商和论文咨询委员会的指导下，在培训的帮助下完成 布法罗大学提供的机会和设备，并通过专业发展 在会议和研讨会上的机会。

Abstract Cryptococcus neoformans is an environmental fungus and opportunistic pathogen of people with compromised immune systems that causes an estimated 181,000 deaths annually. A key step in C. neoformans pathogenesis is adaptation to the host, which is mediated by several signal transduction pathways. Translatome reprogramming, changes in protein synthesis, is a key output of these signal transduction pathways that allows C. neoformans to rapidly fine-tune the stress response, and defects in this process are associated with reduced virulence. The Hog1 p38 MAP kinase (MAPK) module is one signaling module that mediates this process, though the mechanism and effectors by which Hog1 mediates reprogramming are unknown in C. neoformans. We propose to identify the molecular basis of Hog1 activation, and generate a high throughput characterization of its interactome. We also found that another translatome regulatory pathway, the Gcn2 pathway, is differentially regulated in hog1∆, and aim to evaluate the implications of this change in both translatome reprogramming as well as virulence. Thus, we hypothesize that Hog1 mediates changes to a broad interactome via its kinase activity, and that crosstalk with the Gcn2 pathway masks more severe defects in stress tolerance and virulence in hog1∆. We will be testing two specific aims: (1) Determine the mechanism by which Hog1 regulates stress responses in C. neoformans, and (2) Evaluate whether increased eIF2α phosphorylation compensates for loss of Hog1. This project is significant as it will elucidate the mechanism of reprogramming by Hog1, will identify effectors that could be targeted to inhibit this process, and will also examine a convergence point between two major signaling pathways. The overall goal of this research training plan is to equip the candidate with the necessary skills to answer these questions, and to provide them with relevant training to establish themselves as a successful academic investigator studying fungal pathogenesis and stress adaptation. These goals will be accomplished under the guidance of a sponsor and thesis advisory committee, with the help of training opportunities and equipment provided by the University at Buffalo, and through professional development opportunities at conferences and workshops.