title: Molecular basis of sugar recognition by the human L-type lectins ERGIC-53, VIPL, and VIP36.
abstract: ERGIC-53, VIPL, and VIP36 are related type 1 membrane proteins of the mammalian early secretory pathway. They are classified as L-type lectins because of their luminal carbohydrate recognition domain, which exhibits homology to leguminous lectins. These L-type lectins have different intracellular distributions and dynamics in the endoplasmic reticulum-Golgi system of the secretory pathway and interact with N-glycans of glycoproteins in a Ca(2+)-dependent manner, suggesting a role in glycoprotein sorting and trafficking. To understand the function of these lectins, knowledge of their carbohydrate specificity is crucial but only available for VIP36 (Kamiya, Y., Yamaguchi, Y., Takahashi, N., Arata, Y., Kasai, K. I., Ihara, Y., Matsuo, I., Ito, Y., Yamamoto, K., and Kato, K. (2005) J. Biol. Chem. 280, 37178-37182). Here we provide a comprehensive and quantitative analysis of sugar recognition of the carbohydrate recognition domains of ERGIC-53 and VIPL in comparison with VIP36 using a pyridylaminated sugar library in conjunction with frontal affinity chromatography. Frontal affinity chromatography revealed selective interaction of VIPL and VIP36 with the deglucosylated trimannose in the D1 branch of high-mannose-type oligosaccharides but with different pH dependence. ERGIC-53 bound high-mannose-type oligosaccharides with low affinity and broad specificity, not discriminating between monoglucosylated and deglucosylated high-mannosetype oligosaccharides. Based on the sugar-binding properties in conjunction with known features of these proteins, we propose a model for the action of the three lectins in glycoprotein guidance and trafficking. Moreover, structure-based mutagenesis revealed that the sugar-binding properties of these L-type lectins can be switched by single amino acid substitutions.
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: Daiki
authors.initials: D
authors.lastname: Kamiya
authors.forename: Kazuo
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Beat
authors.initials: B
authors.lastname: Nyfeler
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Hauri
authors.forename: Koichi
authors.initials: K
authors.lastname: Kato
mesh_terms: D019943:Amino Acid Substitution; D002118:Calcium / Q000737:chemistry / Q000378:metabolism; D002460:Cell Line; D004721:Endoplasmic Reticulum / Q000235:genetics / Q000378:metabolism; D006023:Glycoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006056:Golgi Apparatus / Q000235:genetics / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D037102:Lectins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D037241:Mannose-Binding Lectins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D009844:Oligosaccharides / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding / Q000502:physiology; D021381:Protein Transport / Q000502:physiology; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013329:Structure-Activity Relationship; D013379:Substrate Specificity / Q000502:physiology
chemical_list: D006023:Glycoproteins; C084004:LMAN1 protein, human; C086797:LMAN2 protein, human; C477344:LMAN2L protein, human; D037102:Lectins; D037241:Mannose-Binding Lectins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D009844:Oligosaccharides; D011994:Recombinant Proteins; D002118:Calcium