Rethinking the Yeast Endomembrane System

The budding yeast Saccharomyces cerevisiae is tremendously useful for revealing basic principles of cell biology. An example is the characterization of the endomembrane system, which consists of secretory, endocytic, and autophagic compartments that exchange material by membrane traffic pathways and undergo dynamic transformations. Yeast studies of this topic continue to uncover components and molecular mechanisms. However, questions persist about high-level features of the yeast endomembrane system, including the identities and life cycles of endocytic compartments and the traffic pathways followed by resident proteins of the Golgi apparatus. Time-lapse imaging of endosome and Golgi compartments points to a new synthesis that revises several long-standing assumptions. This updated picture has implications for understanding conserved aspects of the endomembrane system.