The tissue-specific methylation of the human Tyrosine Hydroxylase gene reveals new regulatory elements in the first exon
The tissue-specific methylation of the human Tyrosine Hydroxylase gene reveals new regulatory elements in the first exon
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DOI：
10.1111/j.1471-4159.2005.03173.x
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发表时间：
2005-07-01
影响因子：
4.7
通讯作者：
Meloni, R
中科院分区：
文献类型：
--
作者：
Arányi, T;Faucheux, BA;Meloni, R
位于调控元件中或附近的CpG二核苷酸的甲基化状态影响基因表达。位于人酪氨酸羟化酶（TH）基因5'启动子区外的富含CpG序列似乎影响相邻内含子HUMTH 01微卫星的功能效应。为了鉴定该区域中作用于基因表达的新调控元件，使用亚硫酸氢盐测序方法研究TH CpG岛的甲基化谱。该区域的总体甲基化水平与细胞系中TH表达和不表达状态相关，并且用5-氮杂胞苷进行DNA去甲基化处理增加TH表达。此外，在甲基化CpG的同质背景中，基因第一外显子中的单个CpG分别在TH表达或非表达细胞系、组织和单细胞中恒定地未甲基化或甲基化。进一步的分析确定，该CpG包含在以AP 2、Sp1和KAISO因子的推定结合位点为特征的序列中。该序列的表征表明，这些因子特异性结合其各自的位点。最后，KAISO的结合，转录抑制因子，是由该序列的甲基化，这可能，因此，参与调节TH基因表达根据其甲基化模式的条件。
The methylation status of CpG dinucleotides located in or near regulatory elements affects gene expression. The CpG-rich sequence located outside the 5' promoter region of the human Tyrosine Hydroxylase (TH) gene appears to influence the functional effect of the adjacent intronic HUMTH01 microsatellite. In order to identify new regulatory elements in this region acting on gene expression, the methylation profile of the TH CpG island was investigated using the bisulfite sequencing method. The overall methylation level of this region is correlated to TH-expressing and non-expressing status in cell lines and DNA demethylation treatment with 5-azacytidine increased TH expression. Moreover, in a homogeneous background of methylated CpGs, a single CpG in the first exon of the gene is constantly either unmethylated or methylated in, respectively, TH-expressing or non-expressing cell lines, tissues and single cells. Further analysis ascertained that this CpG is contained in a sequence characterized by putative binding sites for the AP2, Sp1 and KAISO factors. Characterization of this sequence shows that these factors specifically bind their respective sites. Finally, the binding of KAISO, a transcriptional repressor, is conditioned by the methylation of this sequence, which may, thus, participate in the regulation of TH gene expression according to its methylation pattern.