Haidar M A, Loya F, Yang Y, Lin H, Glassman A, Keating M J, Goldwasser E, Albitar M
Division of Laboratory Medicine, University of Texas M.D. Anderson Cancer Center, Houston 77030, USA.
Nucleic Acids Res. 1996 Sep 15;24(18):3621-8. doi: 10.1093/nar/24.18.3621.
Erythropoietin (EPO) plays a key role in erythropoiesis and is expressed predominantly in the fetal liver and in the adult kidney. The EPO gene is up-regulated at the transcriptional level under hypoxic/anemic conditions. We studied the role of the 5'- and 3'-flanking sequences of the mouse EPO gene in its tissue-specific and hypoxia-induced expression by developing transgenic mouse lines carrying chimeric EPO-lacZ gene constructs. Transgenic mice carrying a 6.5 kb segment of the 5'-sequence and most of the EPO gene in which lacZ was substituted for exon 1 (5'-lacZ-EPO) demonstrated induction of lacZ expression following hypoxia/ anemia induction in both the liver and kidney of adult mice. However, transgenic mice carrying the above construct along with the 1.2 kb 3'-flanking sequence (5'-lacZ-EPO-3') showed a high level of lacZ expression following hypoxia/anemia induction in adult kidney but not in adult liver. With the aim of further understanding the role of the 3'-flanking sequence in tissue-specific expression of the EPO gene, we studied the interactions of protein factors with this 1.2 kb 3' region and demonstrated that multiple sets of protein factors interact tissue specifically with a 10 bp sequence, TCAAAGATGG, located downstream of the previously characterized 3' hypoxia-responsive enhancer element.
促红细胞生成素（EPO）在红细胞生成中起关键作用，主要在胎儿肝脏和成年肾脏中表达。在缺氧/贫血条件下，EPO基因在转录水平上被上调。我们通过构建携带嵌合EPO - lacZ基因构建体的转基因小鼠品系，研究了小鼠EPO基因5'和3'侧翼序列在其组织特异性和缺氧诱导表达中的作用。携带5'序列的6.5 kb片段和大部分EPO基因（其中lacZ替代外显子1，即5'-lacZ-EPO）的转基因小鼠在成年小鼠的肝脏和肾脏中，缺氧/贫血诱导后显示出lacZ表达的诱导。然而，携带上述构建体以及1.2 kb 3'侧翼序列（5'-lacZ-EPO-3'）的转基因小鼠在成年肾脏缺氧/贫血诱导后显示出高水平的lacZ表达，但在成年肝脏中未显示。为了进一步了解3'侧翼序列在EPO基因组织特异性表达中的作用，我们研究了蛋白质因子与这个1.2 kb 3'区域的相互作用，并证明多组蛋白质因子与位于先前鉴定的3'缺氧反应增强子元件下游的10 bp序列TCAAAGATGG发生组织特异性相互作用。
