Molecular cloning of a human fucosyltransferase gene that determines expression of the Lewis x and VIM-2 epitopes but not ELAM-1-dependent cell adhesion.
Molecular cloning of a human fucosyltransferase gene that determines expression of the Lewis x and VIM-2 epitopes but not ELAM-1-dependent cell adhesion.
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DOI：
10.1016/s0021-9258(19)47396-1
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发表时间：
1991-09
期刊：
影响因子：
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通讯作者：
J. B. Lowe;J. Kukowska-Latallo;R. P. Nair;R D Larsen;Rory M. Marks;B. Macher;R. Kelly;L. Ernst-L.
中科院分区：
文献类型：
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作者：
J. B. Lowe;J. Kukowska-Latallo;R. P. Nair;R D Larsen;Rory M. Marks;B. Macher;R. Kelly;L. Ernst-L.
我们使用人刘易斯血型岩藻糖基转移酶cDNA和交叉杂交程序分离编码不同岩藻糖基转移酶的人基因。其DNA序列预测了II型跨膜蛋白，其序列与刘易斯岩藻糖基转移酶催化结构域内相应位置的231个氨基酸中的133个相同。当通过转染在培养的细胞系中表达时，该基因决定能够有效利用N-乙酰乳糖胺形成刘易斯x决定簇（Gal β 1- 4 [Fuc α 1- 3]GlcNAc）的岩藻糖基转移酶的表达。相比之下，生物化学和流式细胞术分析表明，该酶不能有效地利用II型受体NeuNAc α 2- 3Gal β 1- 4GlcNAc形成唾液酸刘易斯x决定簇。然而，在中国仓鼠卵巢细胞中，该酶可以决定α 2--3-唾液酸化、α 1--3-岩藻糖基化结构（称为Vim-2）的表达，VIM-2是ELAM-1的推定寡糖配体。使用Vim-2阳性、唾液酸化刘易斯x阴性转染的中国仓鼠卵巢细胞进行的细胞粘附试验表明，Vim-2决定簇的表面表达不足以赋予细胞ELAM-1依赖性粘附特性。这些结果表明，大量的结构相似性可以存在于哺乳动物之间的糖基转移酶与密切相关的酶的性质，从而促进其同源基因的交叉杂交方法的分离。结果进一步表明，Vim-2决定簇的细胞表面表达不一定足以介导ELAM-1依赖性细胞粘附。
We have used the human Lewis blood group fucosyltransferase cDNA and cross-hybridization procedures to isolate a human gene that encodes a distinct fucosyltransferase. Its DNA sequence predicts a type II transmembrane protein whose sequence is identical to 133 of 231 amino acids at corresponding positions within the catalytic domain of the Lewis fucosyltransferase. When expressed by transfection in cultured cell lines, this gene determines expression of a fucosyltransferase capable of efficiently utilizing N-acetyllactosamine to form the Lewis x determinant (Gal beta 1—-4[Fuc alpha 1—-3]GlcNAc). By contrast, biochemical and flow cytometry analyses suggest that the enzyme cannot efficiently utilize the type II acceptor NeuNAc alpha 2—-3Gal beta 1—-4GlcNAc, to form the sialyl Lewis x determinant. In Chinese hamster ovary cells, however, the enzyme can determine expression of the alpha 2—-3-sialylated, alpha 1—-3-fucosylated structure known as VIM-2, a putative oligosaccharide ligand for ELAM-1. Cell adhesion assays using VIM-2-positive, sialyl Lewis x-negative transfected Chinese hamster ovary cells indicate that surface expression of the VIM-2 determinant is not sufficient to confer ELAM-1-dependent adhesive properties upon the cells. These results demonstrate that substantial structural similarities can exist between mammalian glycosyltransferases with closely related enzymatic properties, thus facilitating isolation of their cognate genes by cross-hybridization methods. The results further suggest that cell surface expression of the VIM-2 determinant is not necessarily sufficient to mediate ELAM-1-dependent cell adhesion.