Localization of VIP36 in the Post-Golgi Secretory Pathway Also of Rat Parotid Acinar Cells

• Published in: The journal of histochemistry and cytochemistry Vol. 51; no. 8; pp. 1057 - 1063
• Main Authors: Shimada, Osamu, Hara-Kuge, Sayuri, Yamashita, Katsuko, Tosaka-Shimada, Hisami, Yanchao, Li, Einan, Li, Atsumi, Saoko, Ishikawa, Harunori
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA Histochemical Soc 01-08-2003; SAGE Publications
• Subjects: Animals; Carrier Proteins - metabolism; Cell Membrane - metabolism; Cercopithecus aethiops; Golgi Apparatus - metabolism; Golgi Apparatus - ultrastructure; Immunoblotting; Male; Mannose-Binding Lectins; Membrane Proteins - metabolism; Membrane Transport Proteins; Microscopy, Confocal; Microscopy, Fluorescence; Microscopy, Immunoelectron; Parotid Gland - cytology; Parotid Gland - metabolism; Parotid Gland - ultrastructure; Rats; Rats, Wistar; Secretory Vesicles - metabolism; Tumor Cells, Cultured; Vero Cells; animal lectin; immunoelectron microscopy; parotid acinar cells; post-Golgi secretory pathway; VIP36
• ISSN: 0022-1554; 1551-5044
• DOI: 10.1177/002215540305100809

VIP36 (36-kD vesicular integral membrane protein), originally purified from Madin-Darby canine kidney (MDCK) epithelial cells, belongs to a family of animal lectins and may act as a cargo receptor. To understand its role in secretory processes, we performed morphological analysis of the rat parotid gland. Immunoelectron microscopy provided evidence that endogenous VIP36 is localized in the trans-Golgi network, on immature granules, and on mature secretory granules in acinar cells. Double-staining immunofluorescence experiments confirmed that VIP36 and amylase co-localized in the apical regions of the acinar cells. This is the first study to demonstrate that endogenous VIP36 is involved in the post-Golgi secretory pathway, suggesting that VIP36 plays a role in trafficking and sorting of secretory and/or membrane proteins during granule formation.