title: Sugar-binding properties of VIP36, an intracellular animal lectin operating as a cargo receptor.
abstract: The vesicular integral protein of 36 kDa (VIP36) is an intracellular animal lectin that acts as a putative cargo receptor, which recycles between the Golgi and the endoplasmic reticulum. Although it is known that VIP36 interacts with glycoproteins carrying high mannose-type oligosaccharides, detailed analyses of the sugar-binding specificity that discriminates isomeric oligosaccharide structures have not yet been performed. In the present study, we have analyzed, using the frontal affinity chromatography (FAC) method, the sugar-binding properties of a recombinant carbohydrate recognition domain of VIP36 (VIP36-CRD). For this purpose, a pyridylaminated sugar library, consisting of 21 kinds of oligosaccharides, including isomeric structures, was prepared and subjected to FAC analyses. The FAC data have shown that glucosylation and trimming of the D1 mannosyl branch interfere with the binding of VIP36-CRD. VIP36-CRD exhibits a bell-shaped pH dependence of sugar binding with an optimal pH value of approximately 6.5. By inspection of the specificity and optimal pH value of the sugar binding of VIP36 and its subcellular localization, together with the organellar pH, we suggest that VIP36 binds glycoproteins that retain the intact D1 mannosyl branch in the cis-Golgi network and recycles to the endoplasmic reticulum where, due to higher pH, it releases its cargos, thereby contributing to the quality control of glycoproteins.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Kamiya
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Yamaguchi
authors.forename: Noriko
authors.initials: N
authors.lastname: Takahashi
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Arata
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Kasai
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Ihara
authors.forename: Ichiro
authors.initials: I
authors.lastname: Matsuo
authors.forename: Yukishige
authors.initials: Y
authors.lastname: Ito
authors.forename: Kazuo
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Koichi
authors.initials: K
authors.lastname: Kato
mesh_terms: D002846:Chromatography, Affinity; D004721:Endoplasmic Reticulum / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism*; D006801:Humans; D037241:Mannose-Binding Lectins / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000378:metabolism*; D009844:Oligosaccharides / Q000378:metabolism*; D011485:Protein Binding; D011994:Recombinant Proteins / Q000378:metabolism; D013347:Subcellular Fractions
chemical_list: D006023:Glycoproteins; C086797:LMAN2 protein, human; D037241:Mannose-Binding Lectins; D026901:Membrane Transport Proteins; D009844:Oligosaccharides; D011994:Recombinant Proteins