title: Involvement of VIP36 in intracellular transport and secretion of glycoproteins in polarized Madin-Darby canine kidney (MDCK) cells.
abstract: VIP36, an intracellular lectin that recognizes high mannose-type glycans (Hara-Kuge, S., Ohkura, T., Seko, A., and Yamashita, K. (1999) Glycobiology 9, 833-839), was shown to localize not only to the early secretory pathway but also to the plasma membrane of Madin-Darby canine kidney (MDCK) cells. In the plasma membrane, VIP36 exhibited an apical-predominant distribution, the apical/basolateral ratio being approximately 2. Like VIP36, plasma membrane glycoproteins recognized by VIP36 were found in the apical and basolateral membranes in the ratio of approximately 2 to 1. In addition, secretory glycoproteins recognized by VIP36 were secreted approximately 2-fold more efficiently from the apical membrane than from the basolateral membrane. Thus, the apical/basolateral ratio of the transport of VIP36-recognized glycoproteins was correlated with that of VIP36 in MDCK cells. Upon overproduction of VIP36 in MDCK cells, the apical/basolateral ratios of both VIP36 and VIP36-recognized glycoproteins were changed from approximately 2 to approximately 4, and the secretion of VIP36-recognized glycoproteins was greatly stimulated. In contrast to the overproduction of VIP36, that of a mutant version of VIP36, which has no lectin activity, was of no effect on the distribution of glycoproteins to apical and basolateral membranes and inhibited the secretion of VIP36-recognized glycoproteins. Furthermore, the overproduction of VIP36 greatly stimulated the secretion of a major apical secretory glycoprotein of MDCK cells, clusterin, which was found to carry at least one high mannose-type glycan and to be recognized by VIP36. In contrast to the secretion of clusterin, that of a non-glycosylated apical-secretion protein, galectin-3, was not stimulated through the overproduction of VIP36. These results indicated that VIP36 was involved in the transport and sorting of glycoproteins carrying high mannose-type glycan(s).
authors.affiliation: Department of Biochemistry, Sasaki Institute, 2-2 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan.
authors.forename: Sayuri
authors.initials: S
authors.lastname: Hara-Kuge
authors.forename: Takashi
authors.initials: T
authors.lastname: Ohkura
authors.forename: Hiroko
authors.initials: H
authors.lastname: Ideo
authors.forename: Osamu
authors.initials: O
authors.lastname: Shimada
authors.forename: Saoko
authors.initials: S
authors.lastname: Atsumi
authors.forename: Katsuko
authors.initials: K
authors.lastname: Yamashita
mesh_terms: D000818:Animals; D019921:Biotinylation; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism*; D051152:Clusterin; D004285:Dogs; D006023:Glycoproteins / Q000032:analysis / Q000096:biosynthesis; D006056:Golgi Apparatus / Q000378:metabolism; D007668:Kidney; D007700:Kinetics; D037241:Mannose-Binding Lectins; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins; D018832:Molecular Chaperones / Q000032:analysis / Q000096:biosynthesis; D021381:Protein Transport; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D051152:Clusterin; D006023:Glycoproteins; D037241:Mannose-Binding Lectins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D018832:Molecular Chaperones; D011994:Recombinant Proteins; C490134:VIP36 protein, Canis familiaris