RRC ID |
39008
|
著者 |
Mizuta M, Kurose T, Miki T, Shoji-Kasai Y, Takahashi M, Seino S, Matsukura S.
|
タイトル |
Localization and functional role of synaptotagmin III in insulin secretory vesicles in pancreatic beta-cells.
|
ジャーナル |
Diabetes
|
Abstract |
Pancreatic beta-cells secrete insulin by Ca2+-triggered exocytosis of insulin-containing large dense-core vesicles. Synaptotagmin is a Ca2+/phospholipid-binding protein and is a good candidate for the Ca2+ sensor for exocytosis of synaptic vesicles in neurons. In the present study, we generated a polyclonal antibody against synaptotagmin III, and found that synaptotagmin III immunoreactivity was present at high levels in insulin-containing pancreatic islet cells and insulin-secreting clonal MIN6 cells. In subcellular fractionations of MIN6 cells, synaptotagmin III was recovered in the vesicular fractions containing both insulin and vesicle-associated membrane protein-2 (VAMP-2), but not in synaptophysin-positive fractions. The secretory vesicles immunoprecipitated by anti-VAMP-2 antibody contained synaptotagmin III and insulin. In addition, treatment of streptolysin-O-permeabilized MIN6 cells with anti-synaptotagmin III antibody significantly inhibited Ca2+-triggered insulin secretion. These results indicate that synaptotagmin III is localized in insulin-containing dense-core vesicles in pancreatic beta-cells, and further strongly suggest that synaptotagmin III is the Ca2+ sensor in the exocytosis of insulin secretory vesicles.
|
巻・号 |
46(12)
|
ページ |
2002-6
|
公開日 |
1997-12-1
|
DOI |
10.2337/diab.46.12.2002
|
PMID |
9392487
|
MeSH |
Animals
Antibodies / pharmacology
Blotting, Western
Calcium-Binding Proteins*
Cell Fractionation
Centrifugation, Density Gradient
Cytoplasmic Granules / chemistry*
Cytoplasmic Granules / physiology
Immunohistochemistry
Immunosorbent Techniques
Insulin / metabolism
Insulin Secretion
Islets of Langerhans / ultrastructure*
Male
Membrane Glycoproteins / analysis*
Membrane Glycoproteins / antagonists & inhibitors
Membrane Glycoproteins / physiology*
Membrane Proteins / analysis
Nerve Tissue Proteins / analysis*
Nerve Tissue Proteins / antagonists & inhibitors
Nerve Tissue Proteins / physiology*
R-SNARE Proteins
Rats
Rats, Wistar
Recombinant Proteins
Synaptotagmins
|
IF |
7.72
|
引用数 |
57
|
WOS 分野
|
ENDOCRINOLOGY & METABOLISM
|
リソース情報 |
ヒト・動物細胞 |
COS-7(RCB0539) |