title: Five mouse homologues of the human dendritic cell C-type lectin, DC-SIGN.
abstract: DC-SIGN, a human C-type lectin, is expressed on the surface of dendritic cells (DC), while a closely related human gene, DC-SIGNR or L-SIGN, is found on sinusoidal endothelial cells of liver and lymph node. Both DC-SIGN and DC-SIGNR/L-SIGN can bind ICAM-3 and HIV gp120, and transmit HIV to susceptible cells in trans. Here, we report the cloning of five mouse genes homologous to human DC-SIGN and DC-SIGNR/L-SIGN. Only one gene, named mouse DC-SIGN, is highly expressed in DC, and is not found in a panel of mouse macrophage and lymphocyte cell lines. The other four genes, named mouse SIGNR1 (SIGN-Related gene 1), SIGNR2, SIGNR3 and SIGNR4, are expressed at lower levels in various cells according to RT-PCR and Northern blot analyses on RNA. All the genes of mouse DC-SIGN and SIGNRs map to adjacent regions of chromosome 8 A1.2-1.3. However, like human DC-SIGN, only the mouse DC-SIGN gene is closely juxtaposed to the CD23 gene, while the other four SIGNR genes are located close to each other in a neighboring region. mRNAs of mouse DC-SIGN and three SIGNR genes encode type II transmembrane proteins (DC-SIGN, 238 amino acids; SIGNR1, 325 amino acids; SIGNR3, 237 amino acids; SIGNR4, 208 amino acids), but the SIGNR2 gene only encodes a carbohydrate recognition domain (CRD) without a cytosolic domain and a transmembrane domain (SIGNR2, 178 amino acids). Amino acid sequence similarities between the CRD of human DC-SIGN and the mouse homologues are 67% for DC-SIGN, 69% for SIGNR1, 65% for SIGNR2, 68% for SIGNR3 and 70% for SIGNR4 respectively. However, the membrane proximal neck domains in the mouse genes are much shorter than their counterparts in human DC-SIGN and DC-SIGNR/L-SIGN. This family of mouse C-type lectins is therefore complex, but only one of the new genes, DC-SIGN, is juxtaposed to CD23 and is expressed at high levels in DC.
authors.affiliation: Laboratory of Cellular Physiology and Immunology, Box 176, The Rockefeller University, 1230 York Avenue, New York, NY 10021-6399, USA.
authors.forename: C G
authors.initials: CG
authors.lastname: Park
authors.forename: K
authors.initials: K
authors.lastname: Takahara
authors.forename: E
authors.initials: E
authors.lastname: Umemoto
authors.forename: Y
authors.initials: Y
authors.lastname: Yashima
authors.forename: K
authors.initials: K
authors.lastname: Matsubara
authors.forename: Y
authors.initials: Y
authors.lastname: Matsuda
authors.forename: B E
authors.initials: BE
authors.lastname: Clausen
authors.forename: K
authors.initials: K
authors.lastname: Inaba
authors.forename: R M
authors.initials: RM
authors.lastname: Steinman
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015815:Cell Adhesion Molecules; D003001:Cloning, Molecular; D018076:DNA, Complementary; D003713:Dendritic Cells; D006801:Humans; D037102:Lectins / Q000235:genetics* / Q000302:isolation & purification; D037181:Lectins, C-Type; D051379:Mice / Q000235:genetics*; D008969:Molecular Sequence Data; D011956:Receptors, Cell Surface / Q000235:genetics* / Q000302:isolation & purification; D017455:Receptors, IgE / Q000235:genetics / Q000302:isolation & purification; D017386:Sequence Homology, Amino Acid; D013154:Spleen / Q000166:cytology; D014018:Tissue Distribution; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin
chemical_list: D015815:Cell Adhesion Molecules; D018076:DNA, Complementary; D037102:Lectins; D037181:Lectins, C-Type; D011956:Receptors, Cell Surface; D017455:Receptors, IgE; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin; C433029:CLEC4M protein, human