Taniuchi Fumiko, Higai Koji, Tanaka Tomomi, Azuma Yutaro, Matsumoto Kojiro
Department of Medical Biochemistry, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi, Chiba 274-8510, Japan.
ScientificWorldJournal. 2013;2013:105464. doi: 10.1155/2013/105464. Epub 2013 Mar 3.
The α 1,2-fucosyltransferase I (FUT1) enzyme is important for the biosynthesis of H antigens, Lewis B, and Lewis Y. In this study, we clarified the transcriptional regulation of FUT1 in the DLD-1 colon cancer cell line, which has high expression of Lewis B and Lewis Y antigens, expresses the FUT1 gene, and shows α 1,2-fucosyltransferase (FUT) activity. 5'-rapid amplification of cDNA ends revealed a FUT1 transcriptional start site -10 nucleotides upstream of the site registered at NM_000148 in the DataBase of Human Transcription Start Sites (DBTSS). Using the dual luciferase assay, FUT1 gene expression was shown to be regulated at the region -91 to -81 nt to the transcriptional start site, which contains the Elk-1 binding site. Site-directed mutagenesis of this region revealed the Elk-1 binding site to be essential for FUT1 transcription. Furthermore, transfection of the dominant negative Elk-1 gene, and the chromatin immunoprecipitation (CHIp) assay, supported Elk-1-dependent transcriptional regulation of FUT1 gene expression in DLD-1 cells. These results suggest that a defined region in the 5'-flanking region of FUT1 is critical for FUT1 transcription and that constitutive gene expression of FUT1 is regulated by Elk-1 in DLD-1 cells.
α1,2-岩藻糖基转移酶I（FUT1）对H抗原、Lewis B和Lewis Y的生物合成至关重要。在本研究中，我们阐明了FUT1在DLD-1结肠癌细胞系中的转录调控，该细胞系具有高表达的Lewis B和Lewis Y抗原，表达FUT1基因，并显示出α1,2-岩藻糖基转移酶（FUT）活性。5'-cDNA末端快速扩增揭示了FUT1转录起始位点位于人类转录起始位点数据库（DBTSS）中NM_000148登记位点上游10个核苷酸处。使用双荧光素酶测定法，结果表明FUT1基因表达在转录起始位点上游-91至-81 nt区域受到调控，该区域包含Elk-1结合位点。对该区域进行定点诱变显示Elk-1结合位点对FUT1转录至关重要。此外，转染显性负性Elk-1基因以及染色质免疫沉淀（CHIp）测定法支持了DLD-1细胞中FUT1基因表达的Elk-1依赖性转录调控。这些结果表明，FUT1 5'-侧翼区域中的一个特定区域对FUT1转录至关重要，并且FUT1的组成型基因表达在DLD-1细胞中受Elk-1调控。
