We study basic mechanisms of membrane-bound protein quality control systems. We are interested in how membrane-bound systems select substrates with a goal of identifying cellular pathways regulated by these systems. These systems are important in pathologies related to cell stress, protein misfolding, and protein misregulation. Some of the human conditions linked to these cellular defects include Parkinson’s disease, Alzheimer’s disease, and various cancers. Our longer-term goals are to understand how changing conditions in cells target substrate proteins to these integral-membrane systems.