Critical Reviews in Oral Biology & Medicine, Vol 9, 4-22, Copyright © 1998 by International & American Associations for Dental Research
Intracellular transport and secretion of salivary proteins
D. Castle and A. Castle
Department of Cell Biology, University of Virginia Health Sciences Center, Charlottesville 22908, USA.
Intracellular transport and secretion of salivary proteins are major
activities of salivary acinar cells. While the major intracellular pathway
followed by salivary proteins following their synthesis has been described
previously, there is only limited understanding of how this process is
regulated at the molecular level. Studies of salivary proteins, especially
proline-rich proteins, expressed in an endocrine cell line have begun to
provide insight regarding intermolecular interactions during transport and
the role played by structural signals during intracellular sorting.
Analysis of the secretion of newly synthesized salivary proteins in parotid
tissue has shown that there are multiple pathways of discharge from acinar
cells. While granule exocytosis is the major pathway, at least two other
pathways that export salivary proteins have been found to originate from
maturing secretion granules. These pathways may contribute to other acinar
cell functions, including secretion of proteins in the absence of acute
stimulation and support of the secretory process for fluid and
electrolytes.
