DNA methylation alters chromatin structure and regulates Thy-1 expression in EL-4 T cells.
DNA methylation alters chromatin structure and regulates Thy-1 expression in EL-4 T cells.
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DNA 甲基化改变染色质结构并调节 EL-4 T 细胞中的 Thy-1 表达。
DOI：
10.4049/jimmunol.138.10.3505
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发表时间：
1987
影响因子：
4.4
通讯作者：
K. Gunter
中科院分区：
文献类型：
--
作者：
M. Sneller;K. Gunter
Thy-1在许多物种的各种组织中表现出明显的表达差异，因此，确定可能调节Thy-1表达的可能机制是有意义的。我们通过甲磺酸乙酯（EMS）诱变、抗Thy-1单克隆抗体（mAb）加补体的阴性选择以及荧光激活细胞分选（流式细胞仪）产生了小鼠T细胞淋巴瘤EL-4的Thy-1阴性变体。以这种方式产生的Thy-1表面阴性（Thy-1-）突变体显示不产生可检测的Thy-1 mRNA，但含有完整的Thy-1基因，如通过Southern印迹测定的。在亲本EL-4克隆中已经去甲基化的5' CG序列在EMS诱导的Thy-1-变体中完全甲基化。此外，定位于EL-4中Thy-1基因5'端的DNase I超敏位点在Thy-1-变体中不存在。用5-氮脱氧胞苷（5-dAZA）处理该Thy-1-克隆导致表面Thy-1的再表达、5' CG序列的去甲基化和DNase I超敏感位点的再生。这些研究表明，在Thy-1基因的5'区域中的某些关键DNA序列的甲基化可以改变局部染色质结构并调节该基因的表达。
Thy-1 exhibits marked differences in expression in various tissues in many species; therefore, it is of interest to define possible mechanisms that may regulate Thy-1 expression. We produced Thy-1 negative variants of the murine T cell lymphoma EL-4 by mutagenesis with ethylmethanesulfonate (EMS), negative selection with anti-Thy-1 monoclonal antibodies (mAb) plus complement, and fluorescence-activated cell sorting (FACS). Thy-1 surface negative (Thy-1-) mutants produced in this manner were shown to produce no detectable Thy-1 mRNA, but contained an intact Thy-1 gene as determined by Southern blotting. 5' CG sequences, which had been demethylated in the parent EL-4 clone, were completely methylated in the EMS-induced Thy-1-variant. In addition, a DNase I hypersensitive site that mapped to the 5' end of the Thy-1 gene in EL-4 was absent in the Thy-1- variant. Treatment of this Thy-1- clone with 5-azadeoxycytidine (5-dAZA) resulted in re-expression of surface Thy-1, demethylation of the 5' CG sequences, and regeneration of the DNase I hypersensitive site. These studies indicate that methylation of certain critical DNA sequences in the 5' region of the Thy-1 gene can alter local chromatin structure and regulate expression of this gene.