Although PC12 cells express three synaptotagmin isoforms (Syts I, IV and IX), all of which have been proposed to regulate dense-core vesicle exocytosis, it remains unknown which of the Sytisoforms acts as the major Ca2+ sensor for dense-core vesicle exocytosis. In the present study, it has been shown by immunoaffinity purification and immunocytochemistry that Syts I and IX, but not Syt IV, are present on the same secretory vesicles in PC12 cells. Silencing of Syt IX with specific small interfering RNA significantly reduced high KCl-dependent neuropeptide Y secretion from PC12 cells, whereas silencing of Syt I with specific small interfering RNA had no significant effect. The results indicate that Syts I and IX are not functionally equivalent and that Syt IX, and not Syt I, is indispensable for the regulation of Ca2+-dependent dense-core vesicle exocytosis in PC12 cells.
Skip Nav Destination
Article navigation
Research Article|
June 15 2004
RNA interference-mediated silencing of synaptotagmin IX, but not synaptotagmin I, inhibits dense-core vesicle exocytosis in PC12 cells
Mitsunori FUKUDA
Mitsunori FUKUDA
1
Fukuda Initiative Research Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
1e-mail mnfukuda@brain.riken.go.jp
Search for other works by this author on:
Publisher: Portland Press Ltd
Received:
January 16 2004
Revision Received:
March 08 2004
Accepted:
March 11 2004
Accepted Manuscript online:
March 11 2004
Online ISSN: 1470-8728
Print ISSN: 0264-6021
The Biochemical Society, London ©2004
2004
Biochem J (2004) 380 (3): 875–879.
Article history
Received:
January 16 2004
Revision Received:
March 08 2004
Accepted:
March 11 2004
Accepted Manuscript online:
March 11 2004
Citation
Mitsunori FUKUDA; RNA interference-mediated silencing of synaptotagmin IX, but not synaptotagmin I, inhibits dense-core vesicle exocytosis in PC12 cells. Biochem J 15 June 2004; 380 (3): 875–879. doi: https://doi.org/10.1042/bj20040096
Download citation file:
Sign in
Don't already have an account? Register
Sign in to your personal account
You could not be signed in. Please check your email address / username and password and try again.
Captcha Validation Error. Please try again.