Functional compartmentalization is the hallmark of eukaryotic cellular organization. Just as animals and plants have distinct organs that carry out different functions, cells have organelles. We are especially interested in the catabolic organelles of the endolysosomal system. We use biochemical, biophysical, and genetic approaches, and model cells and organisms including the baker’s yeast Saccharomyces cerevisiae and the nematode worm Caenorhabditis elegans.