MNT OF HYPHAL POLARITY BY DOPA PROTEIN AND ITS ROLE IN ASPERGILLUS PATHOGENESIS

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目及 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 烟曲霉（Af）是侵袭性曲霉病（IA）的主要病因，IA是一种在不断增长的免疫功能低下人群中经常致命的疾病。伊曲康唑和阿替霉素B是目前唯一可用的治疗侵入性菌丝生长逃脱宿主先天免疫系统的病例的方法。 然而，它们在体内的有效性低，IA患者的预后差。寻找（Af）毒力因子一直存在问题，因为明显候选物中的突变不会降低毒力。 有趣的是，大多数影响致病机理的基因减缓了菌丝延伸的速度，也许给了宿主更多的时间来进行防御。菌丝体通过极性菌丝生长在培养基中延伸。 这种生长模式需要不断地将新材料转移到菌丝的生长尖端。 我们的实验室一直参与阐明多巴的功能，多巴是从真菌到哺乳动物进化保守的蛋白质家族的创始成员。 我们实验室的早期工作表明，多巴是一种参与蛋白质运输的必需基因。具体目标1将检验以下假设：建立和维持高度极化菌丝生长的能力是免疫功能低下患者避免先天免疫的关键机制，并且是丝状真菌病原体毒力的主要影响因素。将在动物细胞系中研究影响真菌生长的突变。将在小鼠侵袭性肺曲霉病模型中评估dopA突变体的毒力。具体目标2将测试的假设，即Af多巴（DopeyA）和一个多巴蛋白代表了一种新的和必要的组成部分，细胞蛋白运输所需的极化细胞生长在响应环境信号。DopA蛋白将通过使用GFP融合物定位在活细胞中。多巴在其他已知的极性决定因素的本地化的作用将被调查。多巴相互作用的蛋白质将通过许多方法来确定，以阐明极性生长的机制。这种方法将有助于了解的分子机制，链接到菌丝生长的信号。 具体目标3将测试的假设，Af有一个神秘的性周期，可以操纵发展减数分裂遗传学作为一种工具，为Af。除了性遗传学将是非常宝贵的研究烟曲霉。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Aspergillus fumigatus (Af) is the major cause of invasive aspergillosis (IA), an often-fatal disease in the growing population of immunocompromised individuals. Itraconazole and amphotericin B are the only currently available treatments for those cases where invasive hyphal growth escapes the host's innate immune system. However, their effectiveness in vivo is low and the prognosis for individuals with IA is poor. The search for (Af) virulence factors has been problematic because mutations in the obvious candidates do not reduce virulence. Interestingly, the majority of genes that affect pathogenesis slow the rate of hyphal extension, perhaps giving the host more time to mount a defense. Af grows as a mycelium that extends through medium via polarized hyphal growth. This mode of growth requires that new materials be constantly moved to the growing tip of the hypha. Our laboratory has been involved in elucidating the function of DopA, the founding member of a protein family that is evolutionarily conserved from fungi to mammals. Earlier work from our lab indicates that DopA is an essential gene that is involved in protein trafficking. Specific Aim 1 will test the hypothesis that the ability to establish and maintain highly polarized hyphal growth is a key mechanism for avoidance of innate immunity in immunocompromised patients, and is a major contributing factor in virulence of filamentous fungal pathogens. Mutations that affect fungal growth will be studied in animal cell lines. The virulence of dopA mutants will be assessed in the mouse invasive pulmonary aspergillosis model. Specific Aim 2 will test the hypothesis that Af DopA (DopeyA) and An DopA proteins represent a novel and essential component of cellular protein trafficking required for polarized cell growth in response to environmental signaling. DopA protein will be localized in living cells by using GFP fusions. The role of DopA in the localization of other known polarity determinants will be investigated. DopA interacting proteins will be identified by a number of methods to elucidate the mechanisms of polar growth. This approach will contribute to an understanding of the molecular mechanisms that link signaling to hyphal growth. Specific Aim 3 will test the hypothesis that Af has a cryptic sexual cycle that can be manipulated to develop meiotic genetics as a tool for Af. The addition of sexual genetics will be invaluable to investigators studying Aspergillus fumigatus.