Dynamic Regulation of the Large Exocytotic Fusion Pore in Pancreatic Acinar Cells

• DOI: 10.1091/mbc.e07-01-0024
• Publication Date: 2007-06-28T05:36:04Z
• Authors: Olga Larina; Purnima Bhat; James A. Pickett; Bradley S. Launik...; Amit Shah; Wade A. Kruger; J. Michael Edwardson; Peter Thorn
• Keywords: Granule (geology)

Loss of granule content during exocytosis requires the opening a fusion pore between secretory and plasma membrane. In variety cells, this has now been shown to subsequently close. However, it is still unclear how closure physiologically regulated contentious as relates loss. Here, we examine behavior zymogen in pancreatic acinar cells. By using entry high-molecular-weight dyes from extracellular solution into lumen, show that diameter 29–55 nm. We further by 5 min after fusion, many granules have closed with evidence indicating prelude endocytosis chymotrypsinogen low. Finally, latrunculin B treatment promotes closure, suggesting F-actin affects dynamics. Together, our data do not support classical view cells ends collapse. Instead, for closes, probably transition endocytosis, likely involving an F-actin–dependent mechanism.