My research interest is to understand how eukaryotic cells support the propagation of retroviruslike elements, a group that includes pathogens like HIV-1. These elements have small genomes with limited coding capacities. Thus, the majority of functions needed for their propagation must be supplied by the host organism. The specific goal of my research is to study host genes important for the propagation of Ty elements, which are retroviruslike elements of the experimentally tractable yeast Saccharomyces cerevisiae. We employ different genetic screening procedures to identify cellular genes important for Ty element propagation. Cellular fractionation studies pinpoint how an identified gene acts to propagate Ty elements. Isolated genes are manipulated to create variants, which are reintroduced into yeast cells for functional studies. We also create tagged versions of genes, which allow us to identify where the encoded proteins reside in the cell. Biochemical assays are employed to determine if the enzymes encoded by the Ty elements are affected when particular cellular genes are mutated. All of this information helps us to appreciate the complex interaction between the retroviruslike element and the host cell. Because yeast retroviruslike elements are so similar to human retroviruses like HIV-1, information from our studies may lead to new approaches for the development of antiviral therapies.