| Project/Area Number |
08670032
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
General anatomy (including Histology/Embryology)
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| Research Institution | KITASATO UNIVERSITY |
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Principal Investigator |
TAMAKI Hideaki Kitasato University, School of Medicine, Assistant Professor, 医学部, 講師 (30155246)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1997: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1996: ¥800,000 (Direct Cost: ¥800,000)
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| Keywords | Golgi apparatus / Immunocytochemistry / Ultrathin cryosection / Parotid gland / beta-COP / Mannosidase II / Brefeldin A / Okadaic acid / 外分泌 |
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| Research Abstract |
To study membrane dynamics of the Golgi apparatus, we examined distributional changes of Golgi-associated proteins in rat parotid acinar cells after the treatment with Golgi-disrupting agents by immunoflurorescent microscopy and immunogold labeling on ultrathin cryosections.
In untreated acinar cells, immunoreactivity of beta-COP was mainly associated with the region of Golgi apparatuson which 58K and man II were co-localized. BFA caused rapid redistribution of 58K and man II into the endoplasmic reticulum (ER) accompanied by marked vesiculation of the Golgi stack. beta-COP lost its association with the Golgi region and was dispersed throughout the cytoplasm. OA also induced rapid and marked vesiculation of the stacked structure of the Golgi apparatus, but the redistribution of 58K and man II into the ER could not be observed. Of interest is that beta-COP was markedly accumulated in the region of the disrupting Golgi apparatus on which 58K and man II immunoreactivies were preserved. Detailed observation on ultrathin crysections of OA-treated cells indicated that the Golgi cluster was composed of beta-COP-positive and-negative tubulovesicles.
These results suggested that BFA inhibited attachment of beta-COP to membranes, resulting in the disturbance of transport vesicle formation. The interruption of pre-and intra-Golgi transport caused redistribution of Golgi membrane proteins follwed by disorganization of the stacked structure. OA also induced disorganization of the stack, but the mechanism differed from that of BFA.OA seemed to inhibit the fusion of transport vesicles with the target membranes but not to prevent their formation. As a result, beta-COP-coated membranes failed to be integrated into the Golgi apparatus and accumulated in the Golgi region. Normal transport is quite essential for the maintenance of the stacked structure of the Golgi apparatus.
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