Small RNA regulation of gene expression in Entamoeba

溶组织内阿米巴是一种重要的人体病原体。E. 组织溶解性包括痢疾和肝脓肿，该生物体是一种主要的寄生虫死亡原因， 在全球范围基因表达调控是使寄生虫适应宿主的关键因素 在组织入侵期间，细菌可以破坏环境，并在生命阶段之间转换以在宿主外传播疾病。 内阿米巴的基因调控机制之一是一个强大而复杂的内源性RNAi途径。超过 在过去的几年里，我们对这一途径进行了重要的观察， RNA具有高度不寻常的5 '-聚P末端，并与阿米巴Argonaute 2-2蛋白相关联以介导 转录基因沉默此外，我们还鉴定出内阿米巴含有三种Argonaute蛋白 具有不同的细胞定位和明显的非冗余功能。我们还使用了以下信息 阿米巴RNAi途径，以开发一种新的和强大的基因沉默工具，在内阿米巴的基础上使用一种 “触发”基因。触发基因沉默是高度稳健和稳定的，并由抑制性组蛋白介导 在沉默的基因座上的修饰。我们的目标是集中在RNA干扰阿米巴的方面， 与其他系统相比是独特的，或者与寄生虫生物学的重要方面相交。因此，我们将 (i)确定小RNA“触发物”介导的基因沉默的分子机制，以及（ii） 表征Argonaute RNA诱导沉默复合物的组分。这些数据将 提高我们对内阿米巴RNAi分子机制的理解。我们的工作是在 RNA干扰的基本细胞过程与阿米巴生物学的交叉。出现的数据将 有助于理解阿米巴生物学的基本过程，并扩大有关阿米巴的知识。 RNAi的基本过程。

Entamoeba histolytica, a protozoan parasite, is an important human pathogen. Diseases caused by E. histolytica include dysentery and liver abscesses, and the organism is a leading parasitic cause of death on a global scale. Regulation of gene expression is a key factor that enables the parasite to adapt to the host environment during tissue invasion and to convert between life stages to propagate disease outside the host. One mechanism of gene regulation in Entamoeba is a robust and complex endogenous RNAi pathway. Over the last several years we have made important observations about this pathway including that amebic small RNAs have highly unusual 5'-polyP termini and associate with amebic Argonaute 2-2 protein to mediate transcriptional gene silencing. Additionally, we identified that Entamoeba contains three Argonaute proteins with different cellular localizations and apparently non-redundant functions. We have also used information on the amebic RNAi pathway to develop a novel and robust gene-silencing tool in Entamoeba based on use of a “trigger” gene. Trigger gene silencing is highly robust and stable and is mediated by repressive histone modifications on the trigger-silenced loci. Our goal is to focus on aspects of RNAi in ameba that are either unique compared to other systems or which intersect with important aspects of parasite biology. Thus, we will (i) determine the molecular mechanisms of small RNA “trigger” mediated gene silencing, and (ii) characterize the components of the Argonaute RNA induced silencing complexes. These data will improve our understanding of the molecular mechanisms of RNAi in Entamoeba. Our work is at the intersection of the basic cellular process of RNA-interference and amebic biology. Data that emerge will contribute to both understanding a basic process in amebic biology and to expanding the knowledge about the fundamental process of RNAi.