The significance of lamellated structure of Golgi apparatus in parotid acinar cells.
By reviewing briefly our recent study, the functional significance of lamellated structure of the Golgi apparatus (GA) was discussed. We have examined the structural alterations and distribution of Golgi related proteins in GA disorganized by brefeldin A (BFA), okadaic acid (OA), monensin and nocodazole (NOC) by means of electron microscopy. BFA and OA induced rapid disruption of lamellated structure of GA into groups of small vesicles and tubules. The effect of these drugs was reversible, and lamellated structure recovered immediately after withdrawal of the drugs. Immunoelectron microscopy revealed that the localization of amylase, GF-1 antigen (a resident protein of trans membrane of GA) and cathepsin D was modified considerably in the cells whose lamellated structures were in the middle of disorganization or reconstruction. These modifications include appearance of cathepsin D and GF-1 immunoreactivity in the secretory granules. Furthermore, there was evidence that secretory products were discharged not only into the acinar lumen but also into the baso-lateral spaces. In contrast, the stacked configuration was preserved in GA after treatment with monensin or NOC. Localization of immunoreactivity of the Golgi related proteins was essentially not changed by these drugs. These findings suggested that the cisternal stack of GA was the structural background for the normal sorting of secretory proteins.
Yamashina
S
S
Dept. of Anatomy, Kitasato University School of Medicine, Sagamihara, Japan.
Tamaki
H
H
D000818:Animals; D006056:Golgi Apparatus / Q000187:drug effects / Q000648:ultrastructure*; D010306:Parotid Gland / Q000166:cytology* / Q000648:ultrastructure