Rab3D regulates amylase levels, not agonist-induced amylase release, in AR42J cells

Cellular & Molecular Biology Letters

Robert Raffaniello¹  Saima Limi¹  George Ojakian² 

[1] Hunter College, School of Health Professions, Medical Laboratory Sciences Program, New York, USA$$;Department of Cell Biology, SUNY-Downstate Medical Center, Brooklyn, USA$$

关键词: Amylase;    AR42J cells;    Exocrine;    Rab3D;    Secretion;    Zymogen granules;    GTP-binding protein;    Pancreas;    Cholecystokinin;    Digestive enzyme;   

DOI  :  10.2478/s11658-012-0008-5

学科分类：分子生物学，细胞生物学和基因

来源: Uniwersytet Wroclawski * Wydzial Biotechnologii / University of Wroclaw, Faculty of Biotechnology

【 摘 要 】

Rab3D is a low molecular weight GTP-binding protein that associates with secretory granules in exocrine cells. AR42J cells are derived from rat pancreatic exocrine tumor cells and develop an acinar cell-like phenotype when treated with dexamethasone (Dex). In the present study, we examined the role of Rab3D in Dex-treated AR42J cells. Rab3D expression and localization were analyzed by subcellular fractionation and immunoblotting. The role of Rab3D was examined by overexpressing myc-labeled wild-type-Rab3D and a constitutively active form of Rab3D (Rab3D-Q81L) in AR42J cells. We found that Rab3D is predominantly membrane-associated in AR42J cells and co-localizes with zymogen granules (ZG). Following CCK-8-induced exocytosis, amylase-positive ZGs appeared to move towards the periphery of the cell and co-localization between Rab3D and amylase was less complete when compared to basal conditions. Overexpression of WT, but not mutant Rab3D, resulted in an increase in cellular amylase levels. Overexpression of mutant and WT Rab3D did not affect granule morphology, CCK-8-induced secretion, long-term (48 hr) basal amylase release or granule density. We conclude that Rab3D is not involved in agonist-induced exocytosis in AR42J cells. Instead, Rab3D may regulate amylase content in these cells.

【 授权许可】

Unknown