Investigating the mechanisms that cellular life evolved to regulate gene expression is of fundamental importance for the understanding of how organisms develop and survive in their environment. RNA interference (RNAi) is an important mechanism of gene regulation, present in most eukaryotic organisms, including plants. Argonaute proteins are central components of RNAi. They bind a vast variety of RNA molecules of 20-24 nucleotide length, termed small silencing RNA (sRNA), and by targeting RNA and DNA through sequence complementarity they regulate the expression of a great amount of genes. Argonautes perform some of their important functions in association with endomembranes, but what processes require membrane-bound argonautes as well as what mechanism mediates such association are still largely unknown. In this thesis I describe the work I have done on plant Argonaute proteins to advance our understanding of how they associate with cellular membranes and of which cellular processes are regulated upon such event.