Goda Emi, Kamiyama Shin, Uno Takaaki, Yoshida Hideki, Ueyama Morio, Kinoshita-Toyoda Akiko, Toyoda Hidenao, Ueda Ryu, Nishihara Shoko
Laboratory of Cell Biology, Department of Bioinformatics, Soka University, 1-236 Tangi-cho, Hachioji, Tokyo, Japan.
J Biol Chem. 2006 Sep 29;281(39):28508-17. doi: 10.1074/jbc.M605045200. Epub 2006 Jul 26.
Sulfation of macromolecules requires the translocation of a high energy form of nucleotide sulfate, i.e. 3'-phosphoadenosine 5'-phosphosulfate (PAPS), from the cytosol into the Golgi apparatus. In this study, we identified a novel Drosophila PAPS transporter gene dPAPST2 by conducting data base searches and screening the PAPS transport activity among the putative nucleotide sugar transporter genes in Drosophila. The amino acid sequence of dPAPST2 showed 50.5 and 21.5% homology to the human PAPST2 and SLALOM, respectively. The heterologous expression of dPAPST2 in yeast revealed that the dPAPST2 protein is a PAPS transporter with an apparent K(m) value of 2.3 microm. The RNA interference of dPAPST2 in cell line and flies showed that the dPAPST2 gene is essential for the sulfation of cellular proteins and the viability of the fly. In RNA interference flies, an analysis of the genetic interaction between dPAPST2 and genes that contribute to glycosaminoglycan synthesis suggested that dPAPST2 is involved in the glycosaminoglycan synthesis and the subsequent signaling. The dPAPST2 and sll genes showed a similar ubiquitous distribution. These results indicate that dPAPST2 may be involved in Hedgehog and Decapentaplegic signaling by controlling the sulfation of heparan sulfate.
大分子的硫酸化作用需要将高能形式的核苷酸硫酸酯，即3'-磷酸腺苷5'-磷酸硫酸酯（PAPS）从细胞质转运到高尔基体中。在本研究中，我们通过数据库搜索并在果蝇假定的核苷酸糖转运蛋白基因中筛选PAPS转运活性，鉴定出一个新的果蝇PAPS转运蛋白基因dPAPST2。dPAPST2的氨基酸序列与人类PAPST2和SLALOM的同源性分别为50.5%和21.5%。dPAPST2在酵母中的异源表达表明，dPAPST2蛋白是一种PAPS转运蛋白，其表观K(m)值为2.3微摩尔。在细胞系和果蝇中对dPAPST2进行RNA干扰表明，dPAPST2基因对于细胞蛋白的硫酸化作用和果蝇的生存能力至关重要。在RNA干扰果蝇中，对dPAPST2与参与糖胺聚糖合成的基因之间的遗传相互作用进行分析表明，dPAPST2参与糖胺聚糖合成及随后的信号传导。dPAPST2和sll基因显示出相似的广泛分布。这些结果表明，dPAPST2可能通过控制硫酸乙酰肝素的硫酸化作用参与刺猬信号通路和果蝇的Decapentaplegic信号传导。
