Genomic cloning and expression of three murine UDP-galactose:: β-N-acetylglucosamine β1,3-galactosyltransferase genes
Genomic cloning and expression of three murine UDP-galactose:: β-N-acetylglucosamine β1,3-galactosyltransferase genes
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DOI：
10.1074/jbc.273.1.58
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发表时间：
1998-01-02
影响因子：
4.8
通讯作者：
Berger, EG
中科院分区：
文献类型：
--
作者：
Hennet, T;Dinter, A;Berger, EG
基于与已知半乳糖基转移酶序列相似的表达序列标签的检测，我们从小鼠基因组文库中分离出三个新的UDP-半乳糖：β-N-乙酰葡糖胺β 1，3-半乳糖基转移酶（β 3GalT）基因，这三个基因被命名为β 3GalT-I、β 3GalT-II和β 3GalT-III，分别编码326、422和331个氨基酸的II型跨膜蛋白。这三个蛋白质构成了一个不同的亚家族，因为它们与其他真核半乳糖基转移酶没有任何序列同一性。此外，三个β 3GalT基因的整个蛋白质编码区包含在单个外显子中，这与β 1，4和α 1，3-半乳糖基转移酶基因的基因组结构形成对比。这三个β 3GalT基因主要在脑组织中表达，完整的表达-长度鼠基因作为昆虫细胞中的重组杆状病毒显示β 3GalT酶对β-连接的GlcNAc具有相同的受体特异性，尽管它们对于该受体和供体UDP-Gal的Km不同。β 3 GalT基因的鉴定强调了半乳糖基转移酶基因家族中存在的结构多样性。
Based on the detection of expressed sequence tags that are similar to known galactosyltransferase sequences, we have isolated three novel UDP-galactose:beta-N-acetylglucosamine beta 1,3-galactosyltransferase (beta 3GalT) genes from a mouse genomic library, The three genes, named beta 3GalT-I, -II, and -III, encode type II transmembrane proteins of 326, 422, and 331 amino acids, respectively, The three proteins constitute a distinct subfamily as they do not share any sequence identity with other eucaryotic galactosyltransferases. Also, the entire protein-coding region of the three beta 3GalT genes was contained in a single exon, which contrasts with the genomic organization of the beta 1,4 and alpha 1,3-galactosyltransferase genes, The three beta 3GalT genes were mainly expressed in brain tissue, The expression of the full-length murine genes as recombinant baculoviruses in insect cells revealed that the beta 3GalT enzymes share the same acceptor specificity for beta-linked GlcNAc, although they differ in their K-m for this acceptor and the donor UDP-Gal. The identification of beta 3GalT genes emphasizes the structural diversity present in the galactosyltransferase gene family.