Gene Expression in Trichomonas vaginalis

描述（由申请人提供）：阴道毛滴虫是世界上最常见的非病毒性性传播感染的病原体，也是美国人口中最普遍的寄生虫。长期感染这种寄生虫的妇女中艾滋病毒传播的增加以及最近耐药滴虫病发病率的增加，使人们有理由更好地了解这种尚未得到充分研究的病原体的生物学特性。本研究旨在为阴道绦虫基因表达调控机制提供基础知识。我们之前对基因表达的分析已经导致了一系列的观察结果，揭示了这种寄生虫和它的人类宿主的转录机制之间的明显差异，这些差异可能被用于药物设计。一种定义转录起始位点并引导RNA聚合酶II （RNAPII）到达该位点的启动子元件，即启动子（Inr），以及一种与Inr和RNAPII相互作用的新型转录因子（IBP39）已被发现并鉴定。我们还发现了阴道绦虫基因中内含子的存在，并开发了体内实验来表征这种原始真核生物的剪接。本研究的具体目标是：(1)确定IBP39与RNA聚合酶II (RNAPII) c端结构域（CTD）的相互作用；(2)鉴定阴道滴虫中包含RNAPII预起始复合物（PIC）的蛋白及其相互作用以协调转录起始的启动子基序；(3)确定毛滴虫中调节RNA剪接的结构特性和基序。这些研究将揭示用于调节原生生物、古生菌、酵母和后生动物基因表达的基本机制的保守和不同特征，为基因调控的进化提供深入的见解。此外，它们将提供基因表达关键特性的关键信息，可能导致可能的治疗应用。

DESCRIPTION (provided by the applicant): Trichomonas vaginalis is the etiologic agent of the most common non-viral sexually transmitted infection worldwide and is the most prevalent parasite found in the US population. Increased transmission of HIV in women chronically infected with this parasite and a recent increase in the incidence of drug resistant Trichomoniasis warrant a better understanding of the biology of this understudied pathogen. The proposed study aims to provide fundamental knowledge of the mechanisms underlying the regulation of gene expression in T. vaginalis. Our previous analyses of gene expression has led to series of observations that reveal distinct differences between the transcriptional machinery of this parasite and its human host that might be exploited for drug design. A promoter element, the intitator (Inr), which defines the start site of transcription and directs RNA polymerase II (RNAPII) to this site and a novel transcription factor (IBP39) that interacts with both the Inr and RNAPII has been discovered and characterized. We have also discovered the presence of introns in T. vaginalis genes and developed in vivo assays to characterize splicing in this primitive eukaryote. The specific aims of the proposed studies to continue this research are: (1) To characterize the interaction between IBP39 and the C-terminal domain (CTD) of RNA polymerase II (RNAPII), (2) To identify T. vaginalis proteins comprising the RNAPII pre-initiation complex (PIC) and the promoter motifs they interact with to coordinate initiation of transcription and (3) To define the structural properties and motifs that regulate RNA splicing in Trichomonas. These studies will reveal both conserved and divergent features of the basic machinery utilized to regulate gene expression in protists, Archaea, yeast and metazoa, providing insight into the evolution of gene regulation. Additionally, they will provide critical information on pivotal properties of gene expression that might lead to possible therapeutic applications.