Expression of Ca2+-dependent Synaptotagmin Isoforms in Mouse and Rat Parotid Acinar Cells.
- Author:
Hae JO
1
;
Hae Mi BYUN
;
Jong Hoon KIM
;
Min Seuk KIM
;
Seung Hyeoi KIM
;
Jeong Hee HONG
;
Jeong Taeg SEO
;
Syng Ill LEE
;
Dong Min SHIN
;
Heung Kyu SON
Author Information
- Publication Type:Original Article ; Research Support, Non-U.S. Gov't
- Keywords: Synaptotagmin; calcium signaling; exocytosis; parotid acinar cells
- MeSH: Synaptotagmins/*metabolism; Signal Transduction; Rats; Protein Isoforms/metabolism; Parotid Gland/cytology/*metabolism; Muscarinic Agonists/pharmacology; Mice; Exocytosis/drug effects/physiology; Carbachol/pharmacology; Calcium/metabolism/*physiology; Animals; Amylases/secretion
- From:Yonsei Medical Journal 2006;47(1):70-77
- CountryRepublic of Korea
- Language:English
- Abstract: Synaptotagmin is a Ca2+ sensing protein, which triggers a fusion of synaptic vesicles in neuronal transmission. Little is known regarding the expression of Ca2+ - dependent synaptotagmin isoforms and their contribution to the release of secretory vesicles in mouse and rat parotid acinar cells. We investigated a type of Ca2+ - dependent synaptotagmin and Ca2+ signaling in both rat and mouse parotid acinar cells using RT-PCR, microfluorometry, and amylase assay. Mouse parotid acinar cells exhibited much more sensitive amylase release in response to muscarinic stimulation than did rat parotid acinar cells. However, transient [Ca2+]i increases and Ca2+ influx in response to muscarinic stimulation in both cells were identical, suggesting that the expression or activity of the Ca2+ sensing proteins is different. Seven Ca2+ - dependent synaptotagmins, from 1 to 7, were expressed in the mouse parotid acinar cells. However, in the rat parotid acinar cells, only synaptotagmins 1, 3, 4 and 7 were expressed. These results indicate that the expression of Ca2+ - dependent synaptotagmins may contribute to the release of secretory vesicles in parotid acinar cells.
