Girard J P, Baekkevold E S, Amalric F
Laboratoire de Biologie Moléculaire Eucaryote du CNRS, Toulouse, France.
FASEB J. 1998 May;12(7):603-12. doi: 10.1096/fasebj.12.7.603.
High endothelial venules (HEVs) are specialized postcapillary venules found in lymphoid organs and chronically inflamed tissues that support high levels of lymphocyte extravasation from the blood. Studies with chlorate, a metabolic inhibitor of sulfation, had previously revealed that production of PAPS (3'-phosphoadenosine-5'-phosphosulfate), the high-energy donor of sulfate, is required for sulfation and high-affinity recognition of HEV sialomucins GlyCAM-1 and CD34 by the lymphocyte homing receptor L-selectin. Here, we report the molecular characterization of a novel 2.5 kb human cDNA from MECA-79+ HEV-derived endothelial cells that encodes the target of chlorate, PAPS synthetase, a multifunctional enzyme containing domains for both ATP sulfurylase and adenosine-5'-phosphosulfate kinase. Functional expression of the isolated cDNA in Chinese hamster ovary cells results in high levels of PAPS synthesis, which is abolished by treatment of the transfected cells with chlorate. Northern blot analysis reveals a wide tissue distribution of PAPS synthetase mRNA in the human body, suggesting that human PAPS synthetase may be important for sulfation not only of HEV sialomucins, but also of many other molecules, including mucins such as the P-selectin ligand PSGL-1, proteoglycans, hormones, neurotransmitters, drugs, and xenobiotics.
高内皮微静脉（HEVs）是存在于淋巴器官和慢性炎症组织中的特殊毛细血管后微静脉，支持高水平的淋巴细胞从血液中渗出。先前使用氯酸盐（一种硫酸化代谢抑制剂）进行的研究表明，硫酸化以及淋巴细胞归巢受体L-选择素对HEV唾液酸粘蛋白GlyCAM-1和CD34的高亲和力识别需要硫酸高能供体PAPS（3'-磷酸腺苷-5'-磷酸硫酸）的产生。在这里，我们报告了一种来自MECA-79 + HEV来源的内皮细胞的新型2.5 kb人类cDNA的分子特征，该cDNA编码氯酸盐的靶标PAPS合成酶，这是一种多功能酶，包含ATP硫酸化酶和腺苷-5'-磷酸硫酸激酶的结构域。分离的cDNA在中国仓鼠卵巢细胞中的功能表达导致高水平的PAPS合成，用氯酸盐处理转染细胞可消除这种合成。Northern印迹分析揭示了PAPS合成酶mRNA在人体中的广泛组织分布，这表明人PAPS合成酶不仅对HEV唾液酸粘蛋白的硫酸化很重要，而且对许多其他分子的硫酸化也很重要，包括粘蛋白如P-选择素配体PSGL-1、蛋白聚糖、激素、神经递质、药物和外源性物质。
