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Protein secretion by rat parotid acinar cells. Pathways and regulation
1Department of Cell Biology, University of Virginia Health Sciences Center, Charlottesville 22908, USA. jdc4r@virginia.edu
Annals of the New York Academy of Sciences
|May 26, 1998
Summary
Rat parotid acinar cells secrete proteins via four distinct pathways. Two pathways are unstimulated, while two are regulated by agonists, including a newly discovered minor pathway.
Area of Science:
- Cell Biology
- Physiology
- Biochemistry
Background:
- Protein secretion is crucial for salivary gland function.
- Parotid acinar cells exhibit complex secretory mechanisms.
- Understanding these pathways is key to salivary gland physiology.
Purpose of the Study:
- To identify and characterize distinct protein secretion pathways in rat parotid acinar cells.
- To differentiate between constitutive and regulated secretory processes.
- To investigate the role of agonists in modulating protein release.
Main Methods:
- Biosynthetic labeling with radioactive amino acids.
- Analysis of protein release timing and composition.
- Assessment of sensitivity to beta-adrenergic and cholinergic agonists.
Main Results:
- Four distinct protein secretion pathways were identified.
- Two unstimulated pathways: a constitutive-like pathway and unstimulated exocytosis.
- Two regulated pathways: a major pathway via stimulated exocytosis and a minor pathway activated by low-dose agonists.
Conclusions:
- Rat parotid acinar cells utilize multiple pathways for protein secretion.
- A novel minor regulated pathway contributes to basal secretion.
- Agonist stimulation differentially regulates secretory pathways.
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