A HUMAN DNA-REPLICATION ORIGIN - LOCALIZATION AND TRANSCRIPTIONAL CHARACTERIZATION
A HUMAN DNA-REPLICATION ORIGIN - LOCALIZATION AND TRANSCRIPTIONAL CHARACTERIZATION
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DOI：
10.1007/bf02451782
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发表时间：
1992-01-01
期刊：
影响因子：
1.6
通讯作者：
FALASCHI, A
中科院分区：
文献类型：
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作者：
BIAMONTI, G;PERINI, G;FALASCHI, A
单拷贝13.7kb人类DNA区域(L30E)。19 p13.3含有髓系HL-60细胞DNA复制的起始点。通过定量聚合酶链式反应，将起始点定位在一个高转录区域，该区域至少包含两个紧密排列的、具有相同转录极性的基因，一个编码lamin B2，另一个编码未知蛋白。起始区在第二转录单位的5‘端与甲基化不足的’‘CpG岛’‘重叠。通过DNase I足迹分析，在第二个基因的启动子上定位了碱性螺旋-环-螺旋(BHLH)DNA结合蛋白如USF/MLTF或MYC-Max的结合位点(CACGTG)。HL-60细胞的DMSO分化，完全关闭复制，也显著减少L30E区域的转录。另一方面，这种处理不会改变CpG岛的甲基化模式，也不会取消bHLH结合位点的DNase I保护。
A single-copy 13.7 kb human DNA region (L30E) located on Ch. 19 p13.3 contains an origin of DNA replication in myeloid HL-60 cells. The origin was localized, by means of quantitative PCR within approximately 3000 bp, in a highly transcribed region containing at least two closely spaced genes with the same polarity of transcription, one encoding lamin B2 and the other an unidentified protein. The origin region overlaps an undermethylated ''CpG island'' at the 5'-end of the second transcription unit. A binding site (CACGTG) for basic helix-loop-helix (bHLH) DNA binding proteins such as USF/MLTF or MYC-MAX was located by DNase I footprinting analysis in the promoter of the second gene. DMSO differentiation of HL-60 cells, that completely shuts off replication, also drastically reduces the transcription of L30E region. On the other hand such treatment does not modify the methylation pattern of the CpG island and does not abolish the DNase I protection of the bHLH binding site.