Role of the actin cytoskeleton in acinar cell protein secretion

All eukaryotic cells, including the pancreatic acinar cell, tightly control organization of their cytoplasm which in large part relies on the cytoskeleton. The cytoskeleton is comprised of three filament types: microtubules (tubulin), intermediate filaments (keratins), and microfilaments (actin). In addition to characteristics common to all cells, the pancreatic acinar cell is a polarized epithelial cell with a vectorial arrangement of the secretory machinery and apically-directed protein secretion, with important roles of the cytoskeleton in this polarity. The most investigated of the cytoskeleton elements in the acinar cell are actin-based microfilaments which are involved in regulated protein secretion. The development of the fluorescent Lifeact probe for realtime visualization of actin dynamics in live cells makes this an exciting time for the field. The dynamic rearrangement of the actin cytoskeleton associated with protein secretion is the focus of this review.