Characterization of a novel C-type lectin-like gene, LSECtin: demonstration of carbohydrate binding and expression in sinusoidal endothelial cells of liver and lymph node

• Published in: The Journal of biological chemistry 2004-04, Vol.279 (18), p.18748-18758
• Main Authors: Liu, Wanli, Tang, Li, Zhang, Ge, Wei, Handong, Cui, Yufang, Guo, Lihai, Gou, Zikuan, Chen, Xiaoxiao, Jiang, Daifeng, Zhu, Yunping, Kang, Gefei, He, Fuchu
• Format: Article
• Language: English
• Subjects: Base Sequence; Binding Sites; Carbohydrate Metabolism; Cell Adhesion Molecules - genetics; Cell Line, Tumor; Cells, Cultured; Chromosome Mapping; Chromosomes, Human, Pair 19; Cloning, Molecular; Dendritic Cells - cytology; Endothelial Cells - chemistry; Humans; Lectins, C-Type - analysis; Lectins, C-Type - genetics; Lectins, C-Type - metabolism; Liver - chemistry; Liver - cytology; LSECTin; Lymph Nodes - chemistry; Lymph Nodes - cytology; Molecular Sequence Data; Receptors, Cell Surface - genetics; Receptors, IgE - genetics; RNA, Messenger - analysis; Tissue Distribution
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M311227200

A new C-type lectin-like gene encodes 293 amino acids and maps to chromosome 19p13.3 adjacent to the previously described C-type lectin genes, CD23, dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN), and DC-SIGN-related protein (DC-SIGNR). The four genes form a tight cluster in an insert size of 105 kb and have analogous genomic structures. The new C-type lectin-like molecule, designated liver and lymph node sinusoidal endothelial cell C-type lectin (LSECtin), is a type II integral membrane protein of approximately 40 kDa in size with a single C-type lectin-like domain at the COOH terminus, closest in homology to DC-SIGNR, DC-SIGN, and CD23. LSECtin mRNA was only expressed in liver and lymph node among 15 human tissues tested, intriguingly neither expressed on hematopoietic cell lines nor on monocyte-derived dendritic cells (DCs). Moreover, LSECtin is expressed predominantly by sinusoidal endothelial cells of human liver and lymph node and co-expressed with DC-SIGNR. LSECtin binds to mannose, GlcNAc, and fucose in a Ca(2+)-dependent manner but not to galactose. Our results indicate that LSECtin is a novel member of a family of proteins comprising CD23, DC-SIGN, and DC-SIGNR and might function in vivo as a lectin receptor.