Figure 1.

Model of the function of autophagy in lamellar body maturation in the swim bladder and lung. In the epithelial cells of these organs, autophagosomes are formed and fuse with immature lamellar bodies to increase their size and expand surfactant lipid storage. After the fusion of lamellar bodies with the plasma membrane, the surfactant is secreted and spread on the air-liquid interface as a lipid monolayer in order to lower the surface tension. Autophagy increases the size and lipid contents of lamellar bodies by remobilizing the surfactant lipids and membranes