TY - JOUR
T1 - Differential distribution of synaptotagmin-1, -4, -7, and -9 in rat adrenal chromaffin cells
AU - Matsuoka, Hidetada
AU - Harada, Keita
AU - Nakamura, Jun
AU - Fukuda, Mitsunori
AU - Inoue, Masumi
N1 - Funding Information:
This work was supported in part by MEXT KAKENHI (21026029 to M.I.) and JSPS KAKENHIs (21500360 to M.I. and 22790222 to H.M.). H.Matsuoka.K.Harada.M.Inoue(*) Department of Cell and Systems Physiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu 807-8555, Japan e-mail: minoue@med.uoeh-u.ac.jp
Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2011/4
Y1 - 2011/4
N2 - Neurons and certain kinds of endocrine cells, such as adrenal chromaffin cells, have large dense-core vesicles (LDCVs) and synaptic vesicles or synaptic-like microvesicles (SLMVs). These secretory vesicles exhibit differences in Ca2+ sensitivity and contain diverse signaling substances. The present work was undertaken to identify the synaptotagmin (Syt) isoforms present in secretory vesicles. Fractionation analysis of lysates of the bovine adrenal medulla and immunocytochemistry in rat chromaffin cells indicated that Syt 1 was localized in LDCVs and SLMVs, whereas Syt 7 was the predominant isoform present in LDCVs. In contrast to PC12 cells and the pancreatic β cell line INS-1, Syt 9 was not immunodetected in LDCVs in rat chromaffin cells. Double-staining revealed that Syt 9-like immunoreactivity was nearly identical with fluorescent thapsigargin binding, suggesting the presence of Syt 9 in the endoplasmic reticulum (ER).The exogenous expression of Syt 1-GFP in INS-1 cells, which had a negligible level of endogenous Syt 1, resulted in an increase in the amount of Syt 9 in the ER, suggesting that Syt 9 competes with Syt 1 for trafficking from the ER to the Golgi complex. We conclude that LDCVs mainly contain Syt 7, whereas SLMVs contain Syt 1, but not Syt 7, in rat and bovine chromaffin cells.
AB - Neurons and certain kinds of endocrine cells, such as adrenal chromaffin cells, have large dense-core vesicles (LDCVs) and synaptic vesicles or synaptic-like microvesicles (SLMVs). These secretory vesicles exhibit differences in Ca2+ sensitivity and contain diverse signaling substances. The present work was undertaken to identify the synaptotagmin (Syt) isoforms present in secretory vesicles. Fractionation analysis of lysates of the bovine adrenal medulla and immunocytochemistry in rat chromaffin cells indicated that Syt 1 was localized in LDCVs and SLMVs, whereas Syt 7 was the predominant isoform present in LDCVs. In contrast to PC12 cells and the pancreatic β cell line INS-1, Syt 9 was not immunodetected in LDCVs in rat chromaffin cells. Double-staining revealed that Syt 9-like immunoreactivity was nearly identical with fluorescent thapsigargin binding, suggesting the presence of Syt 9 in the endoplasmic reticulum (ER).The exogenous expression of Syt 1-GFP in INS-1 cells, which had a negligible level of endogenous Syt 1, resulted in an increase in the amount of Syt 9 in the ER, suggesting that Syt 9 competes with Syt 1 for trafficking from the ER to the Golgi complex. We conclude that LDCVs mainly contain Syt 7, whereas SLMVs contain Syt 1, but not Syt 7, in rat and bovine chromaffin cells.
KW - Chromaffin cell
KW - Chromaffin granules
KW - PC12
KW - Rat (Wistar, male)
KW - Synaptic-like microvesicle
KW - Synaptotagmin
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U2 - 10.1007/s00441-011-1131-8
DO - 10.1007/s00441-011-1131-8
M3 - Article
C2 - 21287204
AN - SCOPUS:79953821048
SN - 0302-766X
VL - 344
SP - 41
EP - 50
JO - Cell and Tissue Research
JF - Cell and Tissue Research
IS - 1
ER -