Small RNAs and Regulation of Gene Expression in Entamoeba histolytica
Entamoeba histolytica harbors a variety of small RNA populations as well as homologues of proteins of the RNA interference (RNAi) pathway, suggesting the presence of a functional RNAi pathway in this unicellular eukaryote. Additionally, several attempts in adapting RNAi-based gene-silencing techniques in E. histolytica were successful, proving that a functional RNAi pathway is indeed present in this protozoan parasite. The most abundant small RNA population has a 5′-polyphosphate structure indicating a Dicer-independent biogenesis pathway. Bioinformatic and functional analyses of small RNAs highlights a role in gene silencing, which contributes to strain-specific gene expression patterns. However, whether the small RNAs have regulatory roles contributing to gene expression changes during tissue invasion or developmental changes is not known. Furthermore, the exact mechanism by which the small RNAs mediate gene expression regulation is also not known. In this chapter we give an overview on the known elements of the Entamoeba RNAi pathway, the characteristics of the small RNA populations, and summarize the insights we have gained from studying gene expression regulation by small RNAs.
KeywordsGene Silence Small RNAs Entamoeba Histolytica RNAi Pathway Histolytica Trophozoite