Transcriptional Control in Entamoeba: Something Old, Something New

Abstract

Entamoeba histolytica is an extracellular protozoan parasite and is a global health problem that kills approximately 100, 000 people annually. The life cycle of Entamoeba consists of two stages - infective trophozoite form and dormant cyst form. Entamoeba infection begins with the entry of cysts into our body with contaminated hands touching to our mouth or intake of contaminated water and food. Trophozoites emerged from the resting cysts in the intestine and relocate to the colon where they multiply by binary fission and can cause invasive or noninvasive disease. The key aspects of their host cell-killing activities are engulfing small/dead host cells by the process called “phagocytosis, " nibbling bigger/live host cells by the process called “trogocytosis, " or inducing apoptotic death of the host cell. It is evident that the pathogenesis, virulence, and development of Entamoeba are controlled by the fine tuning of the process called transcription; however, not much is known about the transcriptional regulation and gene expression in this parasite. Transcription regulatory networks play a key role in global gene expression which control a vast range of biological processes and mostly are well characterized in model organisms like yeast, Drosophila, and mammals; however, these processes are not well understood in a non-model organism like Entamoeba histolytica. In Entamoeba only a few transcription factors (TFs) and DNA motifs have been characterized so far. In this chapter we give an overview of transcriptional regulation features in Entamoeba, summarizing all transcription factors identified up to date and their significant roles in Entamoeba biology.