Lee-Huang S, Lin J J, Kung H F, Huang P L, Lee L, Huang P L
Department of Biochemistry, New York University School of Medicine, NY 10016.
Gene. 1993 Jun 30;128(2):227-36. doi: 10.1016/0378-1119(93)90567-m.
We have reported the cloning and expression of a human erythropoietin (hEp)-encoding cDNA [Lee-Huang, Proc. Natl. Acad. Sci. USA 81 (1984) 2708-2712]. Using this hEp cDNA as a probe, we isolated a 9.3-kb BamHI genomic Ep clone from a human leukocyte library soon thereafter. The size and restriction map of this clone is in agreement with restriction analysis of human genomic DNA probed with the hEp cDNA, demonstrating that this clone is representative of the single hEp gene. This clone is unique in that it extends beyond any reported hEp genomic clone by 3.9 kb on the 5' side and by 1.8 kb on the 3' side. The promoter function of the newly described 5' flanking region has been demonstrated by the expression of biologically active hEp in transfected cells. We find that, despite reports to the contrary, hEp does contain classic canonical TATA boxes and a CAAT box. The 5'-flanking region also contains cytokine-responsive consensus sequences, tissue-specific and metal-responsive elements, CRE and GRE sites, and binding sites for transcription factors, including AP1, NF-kappa beta and Sp1. These regulatory elements have not been found in the hEp genomic clones thus far reported. The identification of these elements and their precise localization in hEp should be useful in studying the regulation of hEp expression, as well as in gene therapy and physiologic modulation of this hormone.
我们已经报道了编码人促红细胞生成素(hEp)的cDNA的克隆与表达[李-黄,《美国国家科学院院刊》81(1984)2708 - 2712]。此后不久,我们使用这个hEp cDNA作为探针,从人白细胞文库中分离出一个9.3kb的BamHI基因组Ep克隆。该克隆的大小和限制酶切图谱与用hEp cDNA探测的人基因组DNA的限制酶切分析结果一致,表明这个克隆代表了单个hEp基因。这个克隆的独特之处在于,它在5'端比任何已报道的hEp基因组克隆延伸了3.9kb,在3'端延伸了1.8kb。新描述的5'侧翼区域的启动子功能已通过转染细胞中生物活性hEp的表达得到证实。我们发现,尽管有相反的报道,但hEp确实包含典型的TATA盒和CAAT盒。5'侧翼区域还包含细胞因子反应性共有序列、组织特异性和金属反应元件、CRE和GRE位点以及转录因子的结合位点,包括AP1、NF-κβ和Sp1。这些调控元件在迄今报道的hEp基因组克隆中尚未发现。这些元件的鉴定及其在hEp中的精确定位对于研究hEp表达的调控以及该激素的基因治疗和生理调节应该是有用的。