McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine and, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205 Predoctoral Training Program in Human Genetics, Johns Hopkins University School of Medicine and, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205.
McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine and, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205.
G3 (Bethesda). 2014 Nov 20;5(1):61-72. doi: 10.1534/g3.114.015636.
Numerous linkage and association studies by our group and others have implicated DPYSL2 at 8p21.2 in schizophrenia. Here we explore DPYSL2 for functional variation that underlies these associations. We sequenced all 14 exons of DPYSL2 as well as 27 conserved noncoding regions at the locus in 137 cases and 151 controls. We identified 120 variants, eight of which we genotyped in an additional 729 cases and 1542 controls. Several were significantly associated with schizophrenia, including a three single-nucleotide polymorphism (SNP) haplotype in the proximal promoter, two SNPs in intron 1, and a polymorphic dinucleotide repeat in the 5'-untranslated region that alters sequences predicted to be involved in translational regulation by mammalian target of rapamycin signaling. The 3-SNP promoter haplotype and the sequence surrounding one of the intron 1 SNPs direct tissue-specific expression in the nervous systems of Zebrafish in a pattern consistent with the two endogenous dpysl2 paralogs. In addition, two SNP haplotypes over the coding exons and 3' end of DPYSL2 showed association with opposing sex-specific risks. These data suggest that these polymorphic, schizophrenia-associated sequences function as regulatory elements for DPYSL2 expression. In transient transfection assays, the high risk allele of the polymorphic dinucleotide repeat diminished reporter expression by 3- to 4-fold. Both the high- and low-risk alleles respond to allosteric mTOR inhibition by rapamycin until, at high drug levels, allelic differences are eliminated. Our results suggest that reduced transcription and mTOR-regulated translation of certain DPYSL2 isoforms increase the risk for schizophrenia.
我们小组和其他小组进行的大量连锁和关联研究表明，8p21.2 上的 DPYSL2 与精神分裂症有关。在这里，我们探索了 DPYSL2 的功能变异，这些变异是这些关联的基础。我们对 137 例病例和 151 例对照中的 DPYSL2 的所有 14 个外显子以及该基因座上的 27 个保守非编码区进行了测序。我们确定了 120 个变体，其中 8 个变体在另外的 729 例病例和 1542 例对照中进行了基因分型。其中一些与精神分裂症显著相关，包括近端启动子中的三个单核苷酸多态性（SNP）单体型、内含子 1 中的两个 SNP 以及 5'非翻译区的多态二核苷酸重复，这些改变了预测参与雷帕霉素信号的哺乳动物靶蛋白翻译调控的序列。3-SNP 启动子单体型和内含子 1 中一个 SNP 周围的序列指导斑马鱼神经系统中的组织特异性表达，这与两个内源性 dpysl2 基因的表达模式一致。此外，编码外显子和 DPYSL2 3' 末端的两个 SNP 单体型与相反的性别特异性风险相关。这些数据表明，这些多态性、与精神分裂症相关的序列作为 DPYSL2 表达的调节元件发挥作用。在瞬时转染实验中，多态二核苷酸重复的高风险等位基因使报告基因的表达减少了 3 到 4 倍。高风险和低风险等位基因都对雷帕霉素的别构 mTOR 抑制有反应，直到药物水平高时，等位基因差异才会消除。我们的研究结果表明，某些 DPYSL2 异构体的转录减少和 mTOR 调节的翻译增加了精神分裂症的风险。
