QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Castle, A. M. Articles by Castle, J. D. Search for Related Content PubMed PubMed Citation Articles by Castle, A. M. Articles by Castle, J. D.

The minor regulated pathway, a rapid component of salivary secretion, may provide docking/fusion sites for granule exocytosis at the apical surface of acinar cells

Anna M. Castle^*, Amy Y. Huang^* and J. David Castle

Department of Cell Biology, University of Virginia Health System, School of Medicine, Charlottesville, VA 22908-0732, USA
^* These authors contributed equally to this work

Author for correspondence (e-mail: jdc4r{at}virginia.edu )

Accepted 3 May 2002

Recently, we reported that the minor regulated and constitutive-like pathways are the main source of resting secretion by parotid acinar cells. Using tissue lobules biosynthetically labeled with [³⁵S]amino acids, we now show that discharge of the minor regulated pathway precedes granule exocytosis stimulated by isoproterenol (1 µM) or carbachol (2 µM). Stimulation of the minor regulated pathway by 40 nM carbachol as well as altering its trafficking, either by adding brefeldin A or by incubating in K⁺-free medium, cause potentiation of amylase secretion stimulated by isoproterenol, suggesting that the minor regulated pathway contributes to the mechanism of potentiation. Both exocytosis of the minor regulated pathway and the potentiation-inducing treatments induce relocation of immunostained subapical puncta of the SNARE protein syntaxin 3 into the apical plasma membrane. Rab11 and possibly VAMP2 may be concentrated in the same relocating foci. These results suggest that the minor regulated pathway and granule exocytosis are functionally linked and that the minor regulated pathway has a second role beyond contributing to resting secretion — providing surface docking/fusion sites for granule exocytosis. In the current model of salivary protein export, discharge of the minor regulated pathway by either ß-adrenergic or cholinergic stimulation is an obligatory first step. Ensuing granule exocytosis is controlled mainly by ß-adrenergic stimulation whereas cholinergic stimulation mainly regulates the number of surface sites where release occurs.

Key words: Exocytosis, Secretion, Syntaxin 3

This article has been cited by other articles:

				E. Baggaley, S. McLarnon, I. Demeter, G. Varga, and J. I. E. Bruce Differential Regulation of the Apical Plasma Membrane Ca2+-ATPase by Protein Kinase A in Parotid Acinar Cells J. Biol. Chem., December 28, 2007; 282(52): 37678 - 37693. [Abstract] [Full Text] [PDF]

				N. Weng, D. D. H. Thomas, and G. E. Groblewski Pancreatic Acinar Cells Express Vesicle-associated Membrane Protein 2- and 8-Specific Populations of Zymogen Granules with Distinct and Overlapping Roles in Secretion J. Biol. Chem., March 30, 2007; 282(13): 9635 - 9645. [Abstract] [Full Text] [PDF]

				C.-C. Wang, H. Shi, K. Guo, C. P. Ng, J. Li, B. Qi Gan, H. Chien Liew, J. Leinonen, H. Rajaniemi, Z. Hong Zhou, et al. VAMP8/Endobrevin as a General Vesicular SNARE for Regulated Exocytosis of the Exocrine System Mol. Biol. Cell, March 1, 2007; 18(3): 1056 - 1063. [Abstract] [Full Text] [PDF]

				Y. Chen, J. D. Warner, D. I. Yule, and D. R. Giovannucci Spatiotemporal analysis of exocytosis in mouse parotid acinar cells Am J Physiol Cell Physiol, November 1, 2005; 289(5): C1209 - C1219. [Abstract] [Full Text] [PDF]

				S.-U. Gorr, S.G. Venkatesh, and D.S. Darling Parotid Secretory Granules: Crossroads of Secretory Pathways and Protein Storage J. Dent. Res., June 1, 2005; 84(6): 500 - 509. [Abstract] [Full Text] [PDF]

				S.-U. Gorr, S.G. Venkatesh, and D.S. Darling Parotid Secretory Granules: Crossroads of Secretory Pathways and Protein Storage Journal of Dental Research, June 1, 2005; 84(6): 500 - 509. [Abstract] [Full Text] [PDF]

				V. Gresz, T.-H. Kwon, H. Gong, P. Agre, M. C. Steward, L. S. King, and S. Nielsen Immunolocalization of AQP-5 in rat parotid and submandibular salivary glands after stimulation or inhibition of secretion in vivo Am J Physiol Gastrointest Liver Physiol, July 1, 2004; 287(1): G151 - G161. [Abstract] [Full Text] [PDF]

				D. D. H. Thomas, N. Weng, and G. E. Groblewski Secretagogue-induced translocation of CRHSP-28 within an early apical endosomal compartment in acinar cells Am J Physiol Gastrointest Liver Physiol, July 1, 2004; 287(1): G253 - G263. [Abstract] [Full Text] [PDF]

				A. Imai, S. Yoshie, T. Nashida, H. Shimomura, and M. Fukuda The small GTPase Rab27B regulates amylase release from rat parotid acinar cells J. Cell Sci., April 15, 2004; 117(10): 1945 - 1953. [Abstract] [Full Text] [PDF]

				J. I. E. Bruce, D. I. Yule, and T. J. Shuttleworth Ca2+-dependent Protein Kinase-A Modulation of the Plasma Membrane Ca2+-ATPase in Parotid Acinar Cells J. Biol. Chem., December 6, 2002; 277(50): 48172 - 48181. [Abstract] [Full Text] [PDF]