Transcriptional Regulation in Giardia lamblia

贾第鞭毛虫的转录调控

• 批准号: 7002746
• 负责人: HEIDI G ELMENDORF
• 金额: $ 26.52万
• 依托单位: GEORGETOWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7002746
• 关键词: DNA directed RNA polymerase; DNA footprinting; Giardia; binding proteins; biochemical evolution; chromatin; enzyme activity; fluorescent in situ hybridization; gel mobility shift assay; gene expression; genetic promoter element; genetic regulation; genetic transcription; messenger RNA; nuclear runoff assay; nucleic acid sequence; structural genes; transcription factor; tubulin

DESCRIPTION: (provided by the applicant): Giardia lamblia is one of the most prevalent parasitic protists and a major cause of diarrheal disease worldwide. A parasitic lifestyle and an extremely early divergence from the eukaryotic tree have permitted Giardia to develop independent solutions to common eukaryotic cellular problems. This biological diversity is instrumental in their ability to cause disease. Notable features of Giardia biology are its two nuclei and its unusually compact and plastic genome. Our long-term goal is to understand the consequences that genomic structure exerts on gene expression. A fundamental starting point is the study of transcriptional regulation. Although 'rules' of transcription have been delineated in higher eukaryotes, extensive work in lower eukaryotes and archaea have clearly indicated many differences in the mechanics of gene expression. Investigation of transcription in Giardia is therefore important both as a prerequisite to understand expression of proteins involved in pathogenesis and also to further our understanding of the evolution of transcriptional machinery. We will test two hypotheses regarding RNA Polymerase II transcription in Giardia lamblia: (I) Giardia will contain a simplified and degenerate core promoter. Two core promoter elements, the TATA box and initiator element (Inr), will be present, although based on their similar sequence profiles, they will be independently able to initiate transcription. A homologue of TATA binding protein will be present to direct transcription from both the TATA box and mnr. (II) The relaxed sequence constraints for transcription initiation and the presence of a tetraploid genome distributed between two nuclei suggests an enhanced role for gene regulation at the chromatin and nuclear level. To experimentally test these hypotheses we will ronduct four specific aims: (1) Characterization of the roles served by core promoter elements in our model promoter - alpha-2 tubulin. (2) Characterization of cryptic promoter elements. (3) Functional rharacterization of a homologue of TATA binding protein (TBP). (4) Examination of transcriptional regulation at the chromatin and nuclear level. These studies will build an understanding of transcription in Giardia lamblia and lay foundations for study of the role of the regulation of gene expression in disease.

描述：（申请人提供的）：贾第二亚布林布利亚是最多的 全世界的流行寄生虫生物和腹泻病的主要原因。 寄生的生活方式和与真核生物的极早期分歧 树已允许贾第鞭毛虫为共同开发独立的解决方案 真核细胞问题。这种生物多样性在 他们引起疾病的能力。贾第鞭毛虫生物学的显着特征是它的两个 核及其异常紧凑和塑性基因组。我们的长期目标是 了解基因组结构对基因表达作用的后果。一个 基本的起点是转录调节的研究。虽然 “转录规则”已在更高的真核生物中划定，广泛 在较低的真核生物和古细菌中的工作清楚地表明 基因表达的力学。贾第二娅转录的调查是 因此，重要的是了解蛋白质表达的先决条件 参与发病机理，并进一步了解我们对进化的理解 转录机械。我们将检验有关RNA的两个假设 贾迪亚·兰布利亚（Giardia Lamblia）的聚合酶II转录：（i）贾第鞭毛虫（Giardia）将包含一个 简化和退化的核心启动子。两个核心启动子元素，塔塔 框和启动器元素（inr）将存在，尽管基于它们的 类似的序列配置文件，它们将独立启动 转录。将出现tata结合蛋白的同源物来指导 Tata盒和MNR的转录。 （ii）放松的序列 转录开始的限制和四倍体的存在 分布在两个核之间的基因组表明基因的作用增强了 调节染色质和核水平。实验测试这些 假设我们将措施四个具体目标：（1）表征 核心启动子元素在我们的模型启动子-Alpha -2小管蛋白中扮演的角色。 （2）表征隐秘的启动子元素。 （3）功能 TATA结合蛋白（TBP）的同源物的鼻细胞化。 （4）考试 在染色质和核水平上的转录调节。这些研究 将建立对贾迪亚·兰布利亚（Giardia Lamblia）转录的理解 研究基因表达在基因表达中的作用的基础 疾病。