Tapia-Páez Isabel, Tammimies Kristiina, Massinen Satu, Roy Ananda L, Kere Juha
Department of Biosciences and Nutrition, 141 57 Huddinge, Karolinska Institute, Stockholm, Sweden.
FASEB J. 2008 Aug;22(8):3001-9. doi: 10.1096/fj.07-104455. Epub 2008 Apr 29.
DYX1C1 was first identified as a candidate gene for dyslexia susceptibility, and its role in controlling neuronal migration during embryogenesis and effect on learning in rodents have been verified. In contrast, genetic association studies have been ambiguous in replicating its effects on dyslexia. To better understand the regulation of DYX1C1 and the possible functional role of genetic variation in the promoter of DYX1C1, we selected three single-nucleotide polymorphisms (SNPs) with predicted functional consequences or suggested associations to dyslexia for detailed study. Electrophoretic mobility shift assays suggested the allele-specific binding of the transcription factors TFII-I (to rs3743205) and Sp1 (to rs16787 and rs12899331) that could be verified by competition assays. In addition, we purified a complex of protein factors binding to the previously suggested dyslexia-related SNP, -3G/A (rs3743205). Three proteins, TFII-I, PARP1, and SFPQ, were unambiguously identified by mass spectrometry and protein sequencing. Two SNPs, rs16787 and rs3743205, showed significant allelic differences in luciferase assays. Our results show that TFII-I, PARP1, and SFPQ proteins, each previously implicated in gene regulation, form a complex controlling transcription of DYX1C1. Furthermore, allelic differences in the promoter or 5' untranslated region of DYX1C1 may affect factor binding and thus regulation of the gene.
DYX1C1最初被鉴定为诵读困难易感性的候选基因，其在胚胎发育过程中控制神经元迁移的作用以及对啮齿动物学习的影响已得到验证。相比之下，基因关联研究在复制其对诵读困难的影响方面一直不明确。为了更好地理解DYX1C1的调控以及DYX1C1启动子中基因变异可能的功能作用，我们选择了三个具有预测功能后果或与诵读困难有潜在关联的单核苷酸多态性（SNP）进行详细研究。电泳迁移率变动分析表明转录因子TFII-I（与rs3743205结合）和Sp1（与rs16787和rs12899331结合）存在等位基因特异性结合，这可通过竞争分析得到验证。此外，我们纯化了与先前提出的与诵读困难相关的SNP -3G/A（rs3743205）结合的蛋白质因子复合物。通过质谱分析和蛋白质测序明确鉴定出三种蛋白质，即TFII-I、PARP1和SFPQ。两个SNP，rs16787和rs3743205，在荧光素酶分析中显示出显著的等位基因差异。我们的结果表明，TFII-I、PARP1和SFPQ蛋白（每种蛋白先前都与基因调控有关）形成一个控制DYX1C1转录的复合物。此外，DYX1C1启动子或5'非翻译区的等位基因差异可能会影响因子结合，从而影响该基因的调控。
