Sulfotransferases of two specificities function in the reconstitution of high endothelial cell ligands for L-selectin.
Sulfotransferases of two specificities function in the reconstitution of high endothelial cell ligands for L-selectin.
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DOI：
10.1083/jcb.145.4.899
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发表时间：
1999-05-17
影响因子：
7.8
通讯作者：
Hemmerich, S
中科院分区：
文献类型：
--
作者：
Bistrup, A;Bhakta, S;Lee, J K;Belov, Y Y;Gunn, M D;Zuo, F R;Huang, C C;Kannagi, R;Rosen, S D;Hemmerich, S
L-选择素是一种凝集素样受体，通过与HEV配体相互作用，介导淋巴细胞在次级淋巴器官高内皮微静脉（HEV）上的滚动。这些配体由唾液粘蛋白的复合物组成，其候选物是糖基化依赖性细胞粘附分子1（GlyCAM-1）、CD 34和足糖萼蛋白。配体必须被唾液酸化、岩藻糖基化和硫酸化，以便被L-选择素最佳识别。我们之前对GlyCAM-1的结构表征已经证明了在唾液酸刘易斯x的情况下的两种硫酸化修饰，Gal-6-硫酸酯和GlcNAc-6-硫酸酯。我们现在报告的Gal-6-磺基转移酶和GlcNAc-6-磺基转移酶，可以修改GlyCAM-1和CD 34的克隆。Gal-6-磺基转移酶具有广泛的组织分布。相反，GlcNAc-6-磺基转移酶高度限制于HEV，如通过北方分析和原位杂交所揭示的。任一酶在中国仓鼠卵巢细胞中的表达，沿着CD 34和岩藻糖基转移酶VII，导致配体活性，如通过L-选择素/IgM嵌合体的结合所检测的。当共表达时，两种磺基转移酶协同作用产生强烈增强的嵌合体结合。
L-selectin, a lectin-like receptor, mediates rolling of lymphocytes on high endothelial venules (HEVs) in secondary lymphoid organs by interacting with HEV ligands. These ligands consist of a complex of sialomucins, candidates for which are glycosylation- dependent cell adhesion molecule 1 (GlyCAM-1), CD34, and podocalyxin. The ligands must be sialylated, fucosylated, and sulfated for optimal recognition by L-selectin. Our previous structural characterization of GlyCAM-1 has demonstrated two sulfation modifications, Gal-6-sulfate and GlcNAc-6-sulfate in the context of sialyl Lewis x. We now report the cloning of a Gal-6-sulfotransferase and a GlcNAc-6-sulfotransferase, which can modify GlyCAM-1 and CD34. The Gal-6-sulfotransferase shows a wide tissue distribution. In contrast, the GlcNAc-6-sulfotransferase is highly restricted to HEVs, as revealed by Northern analysis and in situ hybridization. Expression of either enzyme in Chinese hamster ovary cells, along with CD34 and fucosyltransferase VII, results in ligand activity, as detected by binding of an L-selectin/IgM chimera. When coexpressed, the two sulfotransferases synergize to produce strongly enhanced chimera binding.