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.
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.
Liu
Wanli
W
Department of Genomics and Proteomics, Beijing Institute of Radiation Medicine, Chinese Human Genome Center at Beijing, 27 Taiping Road, Beijing 100850, People's Republic of China.
Tang
Li
L
Zhang
Ge
G
Wei
Handong
H
Cui
Yufang
Y
Guo
Lihai
L
Gou
Zikuan
Z
Chen
Xiaoxiao
X
Jiang
Daifeng
D
Zhu
Yunping
Y
Kang
Gefei
G
He
Fuchu
F
D001483:Base Sequence; D001665:Binding Sites; D050260:Carbohydrate Metabolism; D015815:Cell Adhesion Molecules / Q000235:genetics; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D002874:Chromosome Mapping; D002888:Chromosomes, Human, Pair 19; D003001:Cloning, Molecular; D003713:Dendritic Cells / Q000166:cytology; D042783:Endothelial Cells / Q000737:chemistry*; D006801:Humans; D037181:Lectins, C-Type / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D008099:Liver / Q000737:chemistry / Q000166:cytology; D008198:Lymph Nodes / Q000737:chemistry / Q000166:cytology; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000032:analysis; D011956:Receptors, Cell Surface / Q000235:genetics; D017455:Receptors, IgE / Q000235:genetics; D014018:Tissue Distribution; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin
D015815:Cell Adhesion Molecules; D037181:Lectins, C-Type; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D017455:Receptors, IgE; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin; C433029:CLEC4M protein, human