| The discovery of RNA interference (RNAi) has shed new light on the roles that RNA molecules play in the cell, from viral defense to translational repression and development. Although there is much we have learned, we are still only beginning to understand the degree to which the RNA interference machinery (known as RISC) impacts other cellular processes. Furthermore, there is much that we still have to learn about the machinery itself and how it assembles. Using a variety of biochemical approaches in the Drosophila model system, I have defined various stages of RISC assembly and describe three distinct complexes that form as the assembly pathway proceeds. I have characterized these complexes and have analyzed the requirements for their formation; in the process, demonstrating the importance of Dicer-2 (Dcr-2) in the downstream events of RISC assembly and identifying an unusually large RNA effector complex now known as holo-RISC. My studies help to clarify RISC assembly and provide a simple, well-characterized, and powerful tool for current and future researchers in the field. |
