Cloning and characterization of Siglec-10, a novel sialic acid binding member of the Ig superfamily, from human dendritic cells.
The Siglecs (sialic acid-binding Ig-like lectins) are a subfamily of I-type lectins, which specifically recognize sialic acids. Nine members of the family have been identified thus far. We have obtained a novel cDNA clone from a human dendritic cell cDNA library encoding a protein with sequence and structural features of the Siglec family, hence designated as Siglec-10. The full-length Siglec-10 cDNA encodes a type 1 transmembrane protein containing four extracellular immunoglobulin-like domains, a transmembrane region, and a cytoplasmic tail with two classical immunoreceptor tyrosine-based inhibitory motifs. The N-terminal V-set Ig domain has most of the amino acid residues typical of the Siglecs. Siglec-10 shows the closest homology to Siglec-5 and Siglec-3/CD33. Various cells and cell lines including monocytes and dendritic cells express Siglec-10. High levels of mRNA expression were seen in peripheral blood leukocytes, spleen, and liver. When expressed on COS-7 cells, Siglec-10 was able to bind human red blood cells and soluble sialoglycoconjugates in a sialic acid-dependent manner. The identification of Siglec-10 as a new Siglec family member and its expression profile, together with its sialic acid-dependent binding capacity, suggest that it may be involved in cell-cell recognition by interacting with sialylated ligands expressed on specific cell populations.
Li
N
N
Institute of Immunology, Second Military Medical University, 800 Xiangyin Road, Shanghai 200433, China.
Zhang
W
W
Wan
T
T
Zhang
J
J
Chen
T
T
Yu
Y
Y
Wang
J
J
Cao
X
X
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism; D015152:Blotting, Northern; D019556:COS Cells; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D003713:Dendritic Cells / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism; D015723:Gene Library; D018922:HL-60 Cells; D006367:HeLa Cells; D006801:Humans; D007136:Immunoglobulins / Q000737:chemistry* / Q000235:genetics; D037102:Lectins / Q000737:chemistry* / Q000235:genetics*; D007962:Leukocytes / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D009000:Monocytes / Q000378:metabolism; D009439:Neuraminidase / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D012794:Sialic Acids / Q000378:metabolism; D013154:Spleen / Q000378:metabolism; D014018:Tissue Distribution; D014162:Transfection; D014407:Tumor Cells, Cultured; D020298:U937 Cells
D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D018076:DNA, Complementary; D007136:Immunoglobulins; D037102:Lectins; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; C426228:SIGLEC10 protein, human; C114531:SIGLEC5 protein, human; D012794:Sialic Acids; D009439:Neuraminidase