Expression of FLAG-tagged argonautes in Dictyostelium discoideum

Abstract: Argonautes are conserved RNA-binding proteins that can regulate gene expression post transcriptionally through a process known as RNA interference (RNAi). This is done through the use of small RNAs, e.g. sRNAs that act as a guide for the argonautes, allowing for sequence-specific binding to the target site. This interaction has been studied in many organisms, one of which is the model organism Dictyostelium discoideum. D. discoideum is an amoeba that has been used extensively in genetic experiments due to its unique lifestyle, and ease of use. Being a eukaryotic, unicellular organism, it proves to be a great tool for the study of regulatory systems in eukaryotes, allowing us to study this argonaute-sRNA interaction in detail. By analysing which RNAs bind to the argonautes, we can better understand which genes these proteins regulate and what role RNAi has in the organisms as a whole.  In this study, I investigate three of the five argonautes found in D. discoideum, namely agnA, agnC and agnE. By transforming FLAG-tagged versions of these genes into the amoeba, I successfully express two of these modified proteins in D. discoideum and verified expression by using antibodies designed specifically to recognise the FLAG-tags. This opens up the possibility for the characterisation of the argonaute proteins to better understand their role and function in the regulation of genes.