Prions are misfolded proteins that can aggregate into infectious amyloid fibrils. In yeast, misfolding of the translation termination protein, Sup35p, leads to the formation of a prion called [PSI+]. Fusion of Sup35p to GFP (Sup35p-GFP) leads to the appearance of fluorescent intracellular rings: a hallmark of [PSI+]. Our lab previously found that strains lacking the open reading frame YOR069W have both reduced ring and [PSI+] formation frequencies compared to wild type. Deletion of YOR069W leads to the removal of two genes: VPS5 and VAM10 (YOR068C). VPS5 encodes the retromer complex involved in the recycling of endosome vesicles to the late Golgi and VAM10 encodes a protein involved in vacuolar fusion. We set out to identify whether VPS5 or VAM10 is responsible for the reduced prion formation seen in YOR069W deletion strains. A plasmid containing YOR069W and surrounding regulatory sequences was subjected to site-directed mutagenesis. The start codon of VPS5 was mutated to arginine or the start codon of VAM10 was mutated to isoleucine without disrupting the amino acid sequence of the opposite open reading frame. Mutated plasmids were introduced into the YOR069W deletion background and tested for the ability to form Sup35p-GFP rings. Wild type control plasmids rescued the low ring formation phenotype. However, each individual gene disruption plasmid showed the same low ring formation frequency as the double deletion. These data suggest a synergistic effect of the seemingly unrelated VPS5 and VAM10 genes in prion formation, and furthermore imply that the endosome recycling pathway and vacuolar fusion pathway both contribute to prion formation.