Eric is a molecular and cellular biologist studying functions of the ubiquitin system, which, selectively targets proteins to be degraded by the proteasome, orchestrates responses to various stresses, and controls protein trafficking. He is particularly interested in how different types of ubiquitin polymers signal these distinct functions. He is also developing a yeast model of a rare disease called Lesch-Nyhan syndrome, in which individuals develop severe neurological and behavioral symptoms due to defects in a gene affecting purine metabolism. Recently, he has been focusing on the regulation of a family of yeast purine-cytosine permeases, including the transcriptional controls over their expression, and how, after these proteins bind to their cargo, they are targeted by the ubiquitin system for endocytosis and delivery to the vacuole.