Life Sciences Faculties

A wide range of vertebrate secretory glands, such as the exocrine pancreas and lung goblet cells, package their cargoes in large vesicles (LSVs). The diameter of these vesicles ranges from 1 to 10 µm, roughly the size of a yeast cell. The membrane surface area and internal volume of these vesicles are orders of magnitude greater than those of conventional vesicles (30–500 nm in diameter), posing formidable challenges for vesicle biogenesis, trafficking, fusion, content release, and the maintenance of apical membrane homeostasis. By asking how cells compensate for the significant membrane load introduced by LSVs at the cell surface, our work uncovered an entirely overlooked mode of exocytosis and revealed key components of the intricate molecular mechanisms underlying LSV fusion and exocytosis in exocrine tissues.