FIGURE 4: Snap29 activity in secretion. Release of the pro-inflammatory factor IL-1β requires fusion to the plasma membrane mediated by Snap29 (A). Snap29 also regulates secretion of lysosomes during a developmental cell invasion process in C.elegans (B). Regulation of secretion of glue granules in D. melanogaster salivary glands involves Snap29, which acts in fusion of excess granules to lysosomes (C) (see text for details).