Five mouse homologues of the human dendritic cell C-type lectin, DC-SIGN
Five mouse homologues of the human dendritic cell C-type lectin, DC-SIGN
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DOI：
10.1093/intimm/13.10.1283
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发表时间：
2001-10-01
影响因子：
4.4
通讯作者：
Steinman, RM
中科院分区：
文献类型：
--
作者：
Park, CG;Takahara, K;Steinman, RM
DC-SIGN是一种人类C型凝集素，表达于树突状细胞(DC)表面，而密切相关的人类基因DC-SIGNR或L-SIGN则存在于肝脏和淋巴结的窦内皮细胞上。 DC-SIGN和DC-SIGNR/L-SIGN都可以结合ICAM-3和HIV gp120，并将HIV反式传播给易感细胞。在这里，我们报道了与人类 DC-SIGN 和 DC-SIGNR/L-SIGN 同源的活小鼠基因的克隆。只有一个名为小鼠 DC-SIGN 的基因在 DC 中高表达，并且在一组小鼠巨噬细胞和淋巴细胞细胞系中未发现。根据 RNA 的 RT-PCR 和 Northern blot 分析，另外四个基因，称为小鼠 SIGNR1（SIGN 相关基因 1）、SIGNR2、SIGNR3 和 SIGNR4，在各种细胞中表达水平较低。小鼠 DC-SIGN 和 SIGNR 的所有基因都映射到 8 号染色体 A1.2-1.3 的相邻区域。然而，与人类DC-SIGN一样，只有小鼠DC-SIGN基因与CD23基因紧密相邻，而其他四个SIGNR基因在邻近区域中彼此靠近。小鼠DC-SIGN和三个SIGNR基因的mRNA编码II型跨膜蛋白（DC-SIGN，238个氨基酸；SIGNR1，325个氨基酸；SIGNR3，237个氨基酸；SIGNR4，208个氨基酸），但SIGNR2基因仅编码碳水化合物识别结构域（CRD），没有胞质结构域和跨膜结构域 （SIGNR2，178 个氨基酸）。人DC-SIGN和小鼠同源物的CRD之间的氨基酸序列相似性分别为DC-SIGN为67%、SIGNR1为69%、SIGNR2为65%、SIGNR3为68%和SIGNR4为70%。然而，小鼠基因中的膜近颈结构域比人类 DC-SIGN 和 DC-SIGNR/L-SIGN 中的对应部分短得多。因此，这个小鼠 C 型凝集素家族很复杂，但只有一个新基因 DC-SIGN 与 CD23 并列，并在 DC 中高水平表达。
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 live 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.