JCB logo
Sign up for e-mail content alerts
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
Published 26 April 2004. doi:10.1083/jcb.200312033
The Rockefeller University Press, 0021-9525 $8.00
JCB, Volume 165, Number 2, 255-262
This Article
Right arrow Full Text
Right arrow Full Text (PDF, 3118K)
Right arrow PPT slides of all figures
Right arrow Supplemental Material Index
Right arrow Alert me when this article is cited
Right arrow Citation Map
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new content in the JCB
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Takahashi, N.
Right arrow Articles by Kasai, H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Takahashi, N.
Right arrow Articles by Kasai, H.
Right arrowPubmed/NCBI databases
*Gene*GEO Profiles
*HomoloGene*UniGene
*Compound via MeSH
*Substance via MeSH
Hazardous Substances DB
*12-O-TETRADECANOYLPHORBOL-13-ACETATE
*GLUCOSE
Related Collections
Right arrowRelated Article
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?

Article

 Sequential exocytosis of insulin granules is associated with redistribution of SNAP25

Noriko Takahashi1,2, Hiroyasu Hatakeyama1, Haruo Okado3, Akiko Miwa3, Takuya Kishimoto1, Tatsuya Kojima1, Teruo Abe4, and Haruo Kasai1

1 Department of Cell Physiology, National Institute for Physiological Sciences, Graduate University of Advanced Studies, Myodaiji, Okazaki 444-8585, Japan
2 Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan
3 Department of Molecular Physiology, Tokyo Metropolitan Institute for Neuroscience, Fuchu, Tokyo 183-8526, Japan
4 Department of Cellular Neurobiology, Brain Research Institute, University of Niigata, Niigata, Niigata 951-8585, Japan

Address correspondence to H. Kasai, Dept. of Cell Physiology, National Institute for Physiological Sciences, Graduate University of Advanced Studies, Myodaiji, Okazaki 444-8585, Japan. Tel.: 81-564-55-7831. Fax: 81-564-53-7341. email: hkasai{at}nips.ac.jp

We have investigated sequential exocytosis in ß cells of intact pancreatic islets with the use of two-photon excitation imaging of a polar fluorescent tracer, sulforhodamine B, and a fusion protein comprising enhanced cyan fluorescent protein (ECFP) and the SNARE protein SNAP25 (synaptosome-associated protein of 25 kD) transfected with an adenoviral vector. Sequential exocytosis was found to account for <10% of exocytic events in ß cells stimulated either with glucose under various conditions or by photolysis of a caged-Ca2+ compound. Multigranular exocytosis, in which granule-to-granule fusion occurs before exocytosis, was rarely found. We detected redistribution of ECFP-SNAP25 from the plasma membrane into the membrane of the fused granule occurred in a large proportion (54%) of sequential exocytic events but in only a small fraction (5%) of solitary fusion events. Removal of cholesterol in the plasma membrane by methyl-ß-cyclodextrin facilitated both redistribution of ECFP-SNAP25 and sequential exocytosis by threefold. These observations support the hypothesis that SNAP25 is a plasma membrane factor that is responsible for sequential exocytosis.

Key Words: diabetes; two-photon imaging; secretion; SNARE; pancreatic islet

The online version of this article includes supplemental material.

Abbreviations used in this paper: AM, acetoxymethyl ester; AU, arbitrary unit; [Ca2+]i, cytosolic-free Ca2+ concentration; NP-EGTA, o-nitrophenyl–EGTA; ROI, region of interest; SNAP25, synaptosome-associated protein of 25 kD; SRB, sulforhodamine B.


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?

Related Article

Next vesicle SNAP'd up
Nicole LeBrasseur
J. Cell Biol. 2004 165: 163. [Full Text] [PDF]



This article has been cited by other articles:



  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents