Expression of Ca2+-dependent Synaptotagmin Isoforms in Mouse and Rat Parotid Acinar Cells

• Published in: Yonsei medical journal pp. 70 - 77
• Main Authors: 조해, 변해미, 김종훈, 김민석, 김승회, 홍정희, 서정택, 이승일, 신동민, 손흥규
• Format: Journal Article
• Language: Korean
• Published: 연세대학교의과대학 01.02.2006
• Subjects: 의학일반
• ISSN: 0513-5796; 1976-2437

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. KCI Citation Count: 5