MOLECULAR-CLONING, EXPRESSION, CHROMOSOMAL ASSIGNMENT, AND TISSUE-SPECIFIC EXPRESSION OF A MURINE ALPHA-(1,3)-FUCOSYL-TRANSFERASE LOCUS CORRESPONDING TO THE HUMAN ELAM-1 LIGAND FUCOSYL-TRANSFERASE
MOLECULAR-CLONING, EXPRESSION, CHROMOSOMAL ASSIGNMENT, AND TISSUE-SPECIFIC EXPRESSION OF A MURINE ALPHA-(1,3)-FUCOSYL-TRANSFERASE LOCUS CORRESPONDING TO THE HUMAN ELAM-1 LIGAND FUCOSYL-TRANSFERASE
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DOI：
10.1074/jbc.270.42.25047
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发表时间：
1995-10-20
影响因子：
4.8
通讯作者：
LOWE, JB
中科院分区：
文献类型：
--
作者：
GERSTEN, KM;NATSUKA, S;LOWE, JB
哺乳动物细胞表面糖缀合物以组织特异性方式展示末端Fuc α 1-3GlcNAc部分。这些寡糖参与选择素依赖性白细胞粘附，并在小鼠胚胎发育过程中参与粘附事件。这些分子的其他功能仍有待确定，相应的α-（1-3）-岩藻糖基转移酶（α 1-3FT）基因的组织特异性表达模式也是如此。本报告表征了与人ELAM配体岩藻糖基转移酶（ELFT，也称为Fuc-TIV）具有77%氨基酸序列同一性的鼠α 1-3FT。相应的基因定位于小鼠9号染色体上与人11号染色体上的Fuc-TIV基因座同源的区域。在体外，鼠α 1-3FT可有效地岩藻糖基化三糖Gal α 1-3Gal β 1-4GlcNAc（表观K-m为0.71 mM），形成植入期小鼠组织中描述的不常见的四糖（Gal α 1-3Gal β 1-4[Fuc α 1-3]GlcNAc）。该酶还可由Gal β 1-4GlcNAc（K-m = 2.05 mM）形成刘易斯x决定簇，并由NeuNAc α 2-3Gal β 1-4GlcNAc（K-m = 1.78 mM）形成唾液酸刘易斯x决定簇。然而，当在维持唾液酸刘易斯x前体的哺乳动物细胞系中表达时，它不产生唾液酸刘易斯x决定簇。来自该基因的转录物在造血器官中积累到低水平，但在胃、小肠、结肠和附睾的上皮细胞中出乎意料地丰富。该基因的上皮细胞特异性表达表明除了其在选择素配体合成中的作用之外，还具有与其不同的功能。
Terminal Fuc alpha 1-3GlcNAc moieties are displayed by mammalian cell surface glycoconjugates in a tissue-specific manner. These oligosaccharides participate in selectin-dependent leukocyte adhesion and have been implicated in adhesive events during murine embryogenesis. Other functions for these molecules remain to be defined, as do the tissue-specific expression patterns of the corresponding alpha-(1-3)-fucosyltransferase (alpha 1-3FT) genes. This report characterizes a murine alpha 1-3FT that shares 77% amino acid sequence identity with human ELAM ligand fucosyltransferase (ELFT, also termed Fuc-TIV). The corresponding gene maps to mouse chromosome 9 in a region of homology with the Fuc-TIV locus on human chromosome 11q. In vitro, the murine (alpha 1-3FT can efficiently fucosylate the trisaccharide Gal alpha 1-3Gal beta 1-4GlcNAc (apparent K-m of 0.71 mM) to form an unusual tetrasaccharide (Gal alpha 1-3Gal beta 1-4[Fuc alpha 1-3]GlcNAc) described in periimplantation mouse tissues. The enzyme can also form the Lewis x determinant from Gal beta 1-4GlcNAc (K-m = 2.05 mM), and the sialyl Lewis x determinant from NeuNAc alpha 2-3Gal beta 1-4GlcNAc (K-m = 1.78 mM). However, it does not yield sialyl Lewis x determinants when expressed in a mammalian cell line that maintains sialyl Lewis x precursors. Transcripts from this gene accumulate to low levels in hematopoietic organs, but are unexpectedly abundant in epithelia that line the stomach, small intestine, colon, and epididymus. Epithelial cell-specific expression of this gene suggests function(s) in addition to, and distinct from, its proposed role in selectin ligand synthesis.