Transcription factor control of Entamoeba development

 描述(申请人提供)：溶组织内阿米巴是一种原生动物寄生虫，是一种重要的人类病原体。由溶组织埃希氏菌引起的疾病包括痢疾和肝脓肿，这种生物是全球范围内主要的寄生性死亡原因。内阿米巴的生命周期包括滋养体和包囊之间的阶段相互转换。重要的是，转变为包囊使病原体传播到新的宿主，而向滋养体的发展允许有机体在宿主中引起侵袭性疾病。因此，阶段相互转换对于疾病的传播和发病是必不可少的。然而，尽管阶段转换是阿米巴生物学的核心，但人们对阶段转换知之甚少。许多因素导致了数据的缺乏，其中包括不能再现组织裂殖吸虫的发育周期。取而代之的是，与溶组织内阿米巴具有相同致病机制的爬行动物阿米巴入侵阿米巴被用作研究内阿米巴发育的模式系统。在侵袭性肠杆菌中，包囊化和激发化都可以在体外高效地重现。然而，直到最近，糟糕的基因组注释和缺乏基因操作的方法阻碍了对这一系统的充分利用。最近对入侵埃希氏菌基因组的重新测序，阶段转换转录组的出版，以及构成和调控基因表达方法的发展，为发现开辟了新的途径。我们的目标是在最近这些成功的基础上，通过研究调节阶段转换的转录因子来识别调节囊化的途径。我们将(I)鉴定两个已知的转录因子，以确定它们在控制阶段中的作用 转换，以及(Ii)确定一个新的转录因子，它控制在早期调节的基因 沉淀法。这些数据将使我们能够第一次深入了解调节内阿米巴发育的分子机制，并可能为阻止这种转变的方法或治疗的新靶点提供重要的见解。解剖发育级联对于理解这种重要的人类病原体的生物学至关重要。

 DESCRIPTION (provided by applicant): Entamoeba histolytica, a protozoan parasite, is an important human pathogen. Diseases caused by E. histolytica include dysentery and liver abscesses, and this organism is a leading parasitic cause of death on a global scale. The life cycle of Entamoeba involves stage inter-conversion between trophozoites and cysts. Importantly, the conversion to cysts allows the pathogen to disseminate to new hosts while development to trophozoites allows the organism to cause invasive disease in the host. Thus, stage interconversion is essential for disease transmission and pathogenesis. However, despite being central to amebic biology, stage conversion is poorly understood. Many factors have contributed to the paucity of data including the inability to reproduce the developmental cycle in E. histolytica. Instead, the reptilian ameba E. invadens, which has the same disease pathogenesis as E. histolytica, has been used as a model system to study Entamoeba development. In E. invadens, both encystation and excystation can be recapitulated with high efficiency in vitro. However, until recently a poorly annotated genome and lack of methods for genetic manipulation have prevented full exploitation of this system. The recent re-sequencing of the E. invadens genome, publication of the transcriptome of stage conversion, and development of methods for constitutive and regulated gene expression open up new avenues for discovery. We aim to build upon these recent successes by studying transcription factors that regulate stage conversion as a means to identify pathways that regulate encystation. We will (i) characterize two known transcription factors to determine their roles in controlling stage conversion, and (ii) identify a new transcription factor that controls genes regulated during early encystation. These data will allow us to gain the first insights into the molecular mechanisms that regulate Entamoeba development and could give important insights into methods for blocking this transition or new targets for therapeutics. Dissecting the developmental cascade is crucial to understanding the biology of this important human pathogen.