Gene Expression in Trichomonas vaginalis

描述(由申请人提供)：阴道毛滴虫是全世界最常见的非病毒性性传播感染的病原体，也是在美国人口中发现的最流行的寄生虫。艾滋病毒在长期感染这种寄生虫的妇女中的传播增加，以及最近耐药滴虫病发病率的增加，需要更好地了解这种未被研究的病原体的生物学。这项拟议的研究旨在为阴道毛滴虫基因表达调控的潜在机制提供基础知识。我们之前对基因表达的分析导致了一系列观察，揭示了这种寄生虫与其人类宿主之间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。已发现并鉴定了一个启动子元件，即启动子(INR)，它定义了转录的起始位置，并将RNA聚合酶II(RNAPII)引导到这个位置，以及一个新的转录因子(IBP39)，它同时与INR和RNAPII相互作用。我们还发现了阴道毛滴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。继续这项研究的具体目的是：(1)表征IBP39与RNA聚合酶II(RNAPII)的C-末端结构域(CTD)的相互作用；(2)鉴定由RNAPII预起始复合体(PIC)组成的阴道毛滴虫蛋白质及其与之相互作用的启动子基序，以协调转录的启动；(3)确定调控滴虫RNA剪接的结构特性和基序。这些研究将揭示用于调控原生动物、古生代、酵母和后生动物基因表达的基本机制的保守和差异特征，为基因调控的进化提供洞察力。此外，它们还将提供有关基因表达的关键特性的关键信息，这些特性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.