Localization of VIP36 in the post-Golgi secretory pathway also of rat parotid acinar cells.
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.
Shimada
Osamu
O
Department of Anatomy, Yamanashi University School of Medicine, Yamanashi, Japan. oshimada@swallow.res.yamanashi-med.ac.jp
Hara-Kuge
Sayuri
S
Yamashita
Katsuko
K
Tosaka-Shimada
Hisami
H
Yanchao
Li
L
Einan
Li
L
Atsumi
Saoko
S
Ishikawa
Harunori
H
D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002522:Chlorocebus aethiops; D006056:Golgi Apparatus / Q000378:metabolism* / Q000648:ultrastructure; D015151:Immunoblotting; D008297:Male; D037241:Mannose-Binding Lectins; D008565:Membrane Proteins / Q000378:metabolism*; D026901:Membrane Transport Proteins; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D016253:Microscopy, Immunoelectron; D010306:Parotid Gland / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar; D022142:Secretory Vesicles / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D014709:Vero Cells
D002352:Carrier Proteins; D037241:Mannose-Binding Lectins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; C490134:VIP36 protein, Canis familiaris