The occurrence of three isoforms of heparan sulfate 6-O-sulfotransferase having different specificities for hexuronic acid adjacent to the targeted N-sulfoglucosamine
The occurrence of three isoforms of heparan sulfate 6-O-sulfotransferase having different specificities for hexuronic acid adjacent to the targeted N-sulfoglucosamine
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DOI：
10.1074/jbc.275.4.2859
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发表时间：
2000-01-28
影响因子：
4.8
通讯作者：
Kimata, K
中科院分区：
文献类型：
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作者：
Habuchi, H;Tanaka, M;Kimata, K
我们之前克隆了硫酸乙酰肝素 6-O-磺基转移酶 (HS6ST) (Habuchi, H.、Kobayashi, M. 和 Kimata, K. (1998) J. Biol. Chem. 273, 9208-9213)。在这项研究中，我们报告了 HS6ST 的三种小鼠亚型、原始人类 HS6ST (HS6ST-1) 的小鼠同源物和两种新型 HS6ST（HS6ST-2 和 HS6ST-3）的克隆和表征。通过与人 HS6ST cDNA 交叉杂交从小鼠脑 cDNA 文库中获得 cDNA。这三个 cDNA 包含单个开放阅读框，预测分别由 401、506 和 470 个氨基酸残基组成的 II 型跨膜蛋白。 HS6ST-1的氨基酸序列与HS6ST-2和HS6ST-3的氨基酸序列分别有51%和57%相同。 HS6ST-2和HS6ST-3具有50%的同一性。每种亚型在 COS-7 细胞中的过度表达导致 HS6ST 活性增加约 10 倍。用抗 FLAG 抗体亲和柱纯化的三种亚型将硫酸盐转移到硫酸乙酰肝素和肝素，但不转移到其他糖胺聚糖。每种异构体对与目标 N-磺基葡萄糖胺相邻的异构体己糖醛酸表现出不同的特异性； HS6ST-1 似乎更喜欢艾杜糖基 N-磺基葡萄糖胺，而 HS6ST-2 有不同的偏好，具体取决于底物浓度，而 HS6ST-3 作用于任一底物。 Northern 分析表明，不同组织中每种信息的表达都是各自亚型的特征。 HS6ST-1在肝脏中强烈表达，HS6ST-2主要在脑和脾中表达。相比之下，HS6ST-3 的表达相当普遍。这些结果表明这些异构体的表达可能以组织特异性方式受到调节，并且每种异构体可能参与具有组织特异性结构和功能的硫酸乙酰肝素的合成。
We previously cloned heparan sulfate 6-O-sulfotransferase (HS6ST) (Habuchi, H., Kobayashi, M., and Kimata, K. (1998) J. Biol. Chem. 273, 9208-9213). In this study, we report the cloning and characterization of three mouse isoforms of HS6ST, a mouse homologue to the original human HS6ST (HS6ST-1) and two novel HS6STs (HS6ST-2 and HS6ST-3). The cDNAs have been obtained from mouse brain cDNA library by cross-hybridization with human HS6ST cDNA The three cDNAs contained single open reading frames that predicted type II transmembrane proteins composed of 401, 506, and 470 amino acid residues, respectively. Amino acid sequence of HS6ST-1 was 51 and 57% identical to those of HS6ST-2 and HS6ST-3, respectively. HS6ST-2 and HS6ST-3 had the 50% identity. Overexpression of each isoform in COS-7 cells resulted in about 10-fold increase of HS6ST activity, The three isoforms purified with anti-FLAG antibody affinity column transferred sulfate to heparan sulfate and heparin but not to other glycosaminoglycans. Each isoform showed different specificity toward the isomeric hexuronic acid adjacent to the targeted N-sulfoglucosamine; HS6ST-1 appeared to prefer the iduronosyl N-sulfoglucosamine while HS6ST-2 had a different preference, depending upon the substrate concentrations, and HS6ST-3 acted on either substrate. Northern analysis showed that the expression of each message in various tissues was characteristic to the respective isoform. HS6ST-1 was expressed strongly in liver, and HS6ST-2 was expressed mainly in brain and spleen. In contrast, HS6ST-3 was expressed rather ubiquitously. These results suggest that the expression of these isoforms may be regulated in tissue specific manners and that each isoform may be involved in the synthesis of heparan sulfates with tissue-specific structures and functions.