Expression of the human acute myeloid leukemia gene AML1 is regulated by two promoter regions
Expression of the human acute myeloid leukemia gene AML1 is regulated by two promoter regions
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DOI：
10.1073/pnas.93.5.1935
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发表时间：
1996-03-05
影响因子：
11.1
通讯作者：
Groner, Y
中科院分区：
文献类型：
--
作者：
Ghozi, MC;Bernstein, Y;Groner, Y
人21号染色体AML 1基因主要在造血系统中表达。在几种白血病相关易位中，AML 1与其他基因融合，融合区域的转录由通常调节AML 1表达的上游序列介导。克隆了AML1基因组5'端序列。在AML1cDNA中发现的两个5'非翻译区（UTR）位于该区域，并确定了它们之间的距离。远端5' UTR位于近端5' UTR上游7kb处。使用引物延伸mRNA，在这些5'UTR上方的两个不同位点处鉴定了转录起始位点。序列分析显示，TATA基序的情况下，和存在的Spl，PU.1，Oct，CRE，Myb，Ets，和Ets样结合位点在两个上游区域。还鉴定了与转录起始位点重叠的几个起始元件（Inr）。将这些近端和远端上游区域及其缺失突变体克隆在荧光素酶报告基因的前面，并用于转染测定。我们证明，这两个上游区域的功能作为造血（Jurkat）和非造血（HEK）细胞系的启动子。这两个启动子的活性是方向依赖性的，并通过异源增强子序列以细胞类型特异性方式增强。这些结果表明，额外的控制元件，无论是阴性或阳性，调节AML 1的组织特异性表达。
The human chromosome 21 AML1 gene is expressed predominantly in the hematopoietic system. In several leukemia-associated translocations AML1 Is fused to other genes and transcription of the fused regions is mediated by upstream sequences that normally regulate the expression of AML1. The 5' genomic region of AML1 was cloned and sequenced. The two 5' untranslated regions (UTRs) previously identified in AML1 cDNAs were located in this region and the distance between them was established. The distal 5' UTR maps over 7 kb upstream of the proximal one, Using primer extension with mRNA, transcription start sites were identified at two distinct sites above these 5' UTRs. Sequence analysis revealed the absence of a TATA motif and the presence of Spl, PU.1, Oct, CRE, Myb, Ets, and Ets-like binding sites in both upstream regions. Several initiator elements (Inr) that overlap the transcription start sites were also identified. These proximal and distal upstream regions and their deletion mutants were cloned in front of a luciferase reporter gene and used in transfection assays. We demonstrate that both upstream regions function as promoters in hematopoietic (Jurkat) and nonhematopoietic (HEK) cell lines. The activity of both promoters was orientation dependent and was enhanced, In a cell-type specific manner, by a heterologous enhancer sequence. These results indicate that additional control elements, either negative or positive, regulate the tissue-specific expression of AML1.