Taniguchi Akiyoshi, Morishima Takashi, Tsujita Yuna, Matsumoto Yoshiko, Matsumoto Kojiro
Biomaterials Center, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
Biochem Biophys Res Commun. 2003 Jan 10;300(2):570-6. doi: 10.1016/s0006-291x(02)02899-1.
In this report, we describe transcriptional regulation of the human Gal beta 1,3 GalNAc alpha 2,3-sialyltransferase II (hST3Gal II) gene. The results of 5'-RACE showed that the forms of two mRNAs differed only in the 5'-untranslated region (Types 1 and 2). According to analysis of the genomic structure, the transcriptional regulation of Type 1 and Type 2 mRNA isoforms depended on the p1 and p2 promoters, respectively. Both the mRNA isoforms were detected in various human tissues except colon, skeletal muscle, and peripheral blood leukocytes by RT-PCR analysis. In colon tissue, the Type 2 mRNA was detected, however, Type 1 mRNA was not detected. To elucidate the molecular basis of hST3Gal II gene expression, we isolated and characterized the function of the genomic region of hST3Gal II containing the p1 and p2 promoters. The activity of p2 promoter is much higher than that of the p1 promoter in the colon adenocarcinoma cell line, COLO205. These results suggest that the hST3Gal II gene is expressed specifically by alternative promoter utilization and is regulated in a tissue-restricted fashion at the level of transcription.
在本报告中，我们描述了人类β1,3-半乳糖基-N-乙酰半乳糖胺α2,3-唾液酸转移酶II（hST3Gal II）基因的转录调控。5'-RACE结果表明，两种mRNA形式仅在5'-非翻译区有所不同（1型和2型）。根据基因组结构分析，1型和2型mRNA亚型的转录调控分别依赖于p1和p2启动子。通过RT-PCR分析，在除结肠、骨骼肌和外周血白细胞外的各种人体组织中均检测到了这两种mRNA亚型。在结肠组织中，检测到了2型mRNA，但未检测到1型mRNA。为了阐明hST3Gal II基因表达的分子基础，我们分离并鉴定了包含p1和p2启动子的hST3Gal II基因组区域的功能。在结肠腺癌细胞系COLO205中，p2启动子的活性远高于p1启动子。这些结果表明，hST3Gal II基因通过选择性启动子利用而特异性表达，并在转录水平上受到组织限制方式的调控。
