TY - JOUR
T1 - Role of VAMP-2, VAMP-7, and VAMP-8 in constitutive exocytosis from HSY cells
AU - Oishi, Yohei
AU - Arakawa, Toshiya
AU - Tanimura, Akihiko
AU - Itakura, Makoto
AU - Takahashi, Masami
AU - Tajima, Yoshifumi
AU - Mizoguchi, Itaru
AU - Takuma, Taishin
N1 - Funding Information:
Acknowledgements We wish to thank Prof. Yosuke Tojyo, as well as Drs. Takao Morita and Akihiko Nezu, Department of Dental Pharmacology, Health Sciences University, for helpful discussion and also Ms. Tamaki Tamaki-Yokohama and Mr. Kouhei Taima for their technical assistance. This work was supported in part by the Academic Sciences Frontier Project and by a grant-in-aid for scientific research (No.15591973 to T. T.) from the Ministry of Education, Culture, Sports, Science, and Technology of Japan.
PY - 2006/3
Y1 - 2006/3
N2 - We evaluated the role of VAMP-2/synaptobrevin, VAMP-7/TI-VAMP, and VAMP-8/endobrevin in exocytic pathways of HSY cells, a human parotid epithelial cell line, by coexpressing these VAMP proteins tagged with green fluorescent protein (GFP) and human growth hormone (hGH) as a secretory cargo. Exocytosis of hGH was constitutive and the fluorescent signal of hGH-GFP was observed in the Golgi area and small vesicles quickly moving throughout the cytoplasm. The cytoplasmic vesicles containing hGH overlapped well with VAMP-7-GFP, but did so scarcely with VAMP-2-GFP or VAMP-8-GFP. However, when the vesicle transport from the trans-Golgi network to the plasma membrane was arrested by incubation at 20°C for 2 h and then released by warming up to 37°C; VAMP-2-GFP and hGH were clearly colocalized together in small cytoplasmic vesicles. Neither VAMP-7-GFP nor hGH-GFP was colocalized with LAMP-1, a marker for lysosomes and late endosomes. These results suggest that (1) VAMP-2 can be one of the v-SNAREs for constitutive exocytosis; (2) VAMP-7 is involved in the constitutive exocytosis as a slow, minor v-SNARE, but not in the lysosomal transport; and (3) VAMP-8 is unlikely to be a v-SNARE for constitutive exocytosis in HSY cells.
AB - We evaluated the role of VAMP-2/synaptobrevin, VAMP-7/TI-VAMP, and VAMP-8/endobrevin in exocytic pathways of HSY cells, a human parotid epithelial cell line, by coexpressing these VAMP proteins tagged with green fluorescent protein (GFP) and human growth hormone (hGH) as a secretory cargo. Exocytosis of hGH was constitutive and the fluorescent signal of hGH-GFP was observed in the Golgi area and small vesicles quickly moving throughout the cytoplasm. The cytoplasmic vesicles containing hGH overlapped well with VAMP-7-GFP, but did so scarcely with VAMP-2-GFP or VAMP-8-GFP. However, when the vesicle transport from the trans-Golgi network to the plasma membrane was arrested by incubation at 20°C for 2 h and then released by warming up to 37°C; VAMP-2-GFP and hGH were clearly colocalized together in small cytoplasmic vesicles. Neither VAMP-7-GFP nor hGH-GFP was colocalized with LAMP-1, a marker for lysosomes and late endosomes. These results suggest that (1) VAMP-2 can be one of the v-SNAREs for constitutive exocytosis; (2) VAMP-7 is involved in the constitutive exocytosis as a slow, minor v-SNARE, but not in the lysosomal transport; and (3) VAMP-8 is unlikely to be a v-SNARE for constitutive exocytosis in HSY cells.
KW - Constitutive exocytosis
KW - SNARE
KW - VAMP-2
KW - VAMP-7
KW - VAMP-8
KW - hGH-GFP
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U2 - 10.1007/s00418-005-0068-y
DO - 10.1007/s00418-005-0068-y
M3 - Article
C2 - 16195891
AN - SCOPUS:32444451792
VL - 125
SP - 273
EP - 281
JO - Zeitschrift für Zellforschung und Mikroskopische Anatomie. Abteilung Histochemie
JF - Zeitschrift für Zellforschung und Mikroskopische Anatomie. Abteilung Histochemie
SN - 0948-6143
IS - 3
ER -