DEFINITION OF THE MINIMAL REQUIREMENTS WITHIN THE HUMAN BETA-GLOBIN GENE AND THE DOMINANT CONTROL REGION FOR HIGH-LEVEL EXPRESSION
DEFINITION OF THE MINIMAL REQUIREMENTS WITHIN THE HUMAN BETA-GLOBIN GENE AND THE DOMINANT CONTROL REGION FOR HIGH-LEVEL EXPRESSION
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DOI：
10.1002/j.1460-2075.1990.tb08100.x
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发表时间：
1990-01-01
期刊：
影响因子：
11.4
通讯作者：
GROSVELD, F
中科院分区：
文献类型：
--
作者：
COLLIS, P;ANTONIOU, M;GROSVELD, F
人类。贝塔。-珠蛋白显性控制区（DCR）先前被确定为人类β蛋白5'末端的一个区域。-globin基因座，它指导高水平的、不依赖整合的、拷贝数依赖的人类β蛋白的表达。-珠蛋白基因在转基因小鼠和稳定转染小鼠红白血病（MEL）细胞中的表达。我们现在分析了组成DCR的元素，通过系统的删除诱变在稳定的MEL转染。我们已经在DNase I超敏位点2和3中鉴定了两个独立的元件，它们包含的片段直接引导了a. β的强转录诱导性。球蛋白基因。虽然其余两个超敏感位点不直接显著的转录诱导，但我们的数据表明，所有四个位点都可能是由DCR赋予的完全调节表达所必需的。我们也测试了一些。beta。在DCR的控制下构建-globin minigene，以评估是否有任何来自基因的局部序列可以在不丧失表达的情况下被移除。我们发现，3‘’增强子可以在不影响表达的情况下被移除，但有一个绝对的要求，即第二个内含子的存在，与该内含子中存在的增强子无关。
The hunman .beta.-globin dominant control region (DCR) was previously identified as a region from the 5'' end of the human .beta.-globin locus which directs high level, site of integration-independent, copy number-dependent expression on a linked human .beta.-globin gene in transgenic mice and stably transfected mouse erythroleukaemia (MEL) cells. We have now analysed the elements comprising the DCR by systematic deletion mutagenesis in stable MEL transfectants. We have identified two independent elements within the DNase I hypersensitive sites 2 and 3, containing fragments which direct strong transcriptional inducibility of a .beta.-globin gene. Whilst the remaining two hypersensitive sites do not direct significant transcriptional induction, our data suggest that all four sites may be necessary for the fully regulated expression conferred by the DCR. We have also tested a number of .beta.-globin minigene constructs under the control of the DCR to assess if any of the local sequences from the gene may be removed without loss of expression. We find that the 3'' enhancer may be removed without affecting expression, but there is an absolute requirement for the presence of the second intron, not related to the enhancer present in that intron.