STRUCTURAL ORGANIZATION AND CHROMOSOMAL ASSIGNMENT OF THE GENE ENCODING THE HUMAN HEPARIN-BINDING EPIDERMAL GROWTH FACTOR-LIKE GROWTH-FACTOR DIPHTHERIA-TOXIN RECEPTOR
STRUCTURAL ORGANIZATION AND CHROMOSOMAL ASSIGNMENT OF THE GENE ENCODING THE HUMAN HEPARIN-BINDING EPIDERMAL GROWTH FACTOR-LIKE GROWTH-FACTOR DIPHTHERIA-TOXIN RECEPTOR
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DOI：
10.1021/bi00082a014
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发表时间：
1993-08-10
期刊：
影响因子：
2.9
通讯作者：
LEE, ME
中科院分区：
文献类型：
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作者：
FEN, Z;DHADLY, MS;LEE, ME
肝素结合表皮生长因子样生长因子(HB-EGF)是新近发现的一种高效的巨噬细胞来源的平滑肌细胞有丝分裂原。它在血管内皮细胞和平滑肌细胞中以高度调控的方式表达，表明该基因在动脉粥样硬化中具有潜在的重要作用。此外，HB-EGF前体最近被发现作为白喉毒素的受体发挥作用。利用HB-EGF基因探针，克隆了编码HB-EGF的人基因。HB-EGF基因包含6个外显子和5个插入序列，跨越14kb的DNA。通过引物延伸和S1核酸酶分析，我们在HB-EGF的5‘端之外定位了一个主要的转录起始点(对应于A残基)14bp。在转录起始点上游没有TATAAA或CCAAT共有序列。经肿瘤坏死因子-α处理的内皮细胞RNA扩增出的扩增带密度是对照组的10倍，提示肿瘤坏死因子-α可提高HB-EGF的mRNA水平。瞬时报告基因转染实验表明，2.0kb的HB-EGF 5‘侧翼序列在牛主动脉内皮细胞中具有启动子活性。通过对人-鼠体细胞杂交细胞系DNA的分析，我们将HB-EGF基因定位在5号染色体上。功能研究表明，5号染色体与白喉毒素易感性有关。
Heparin-binding epidermal growth factor-like growth factor(HB-EGF) is a recently identified, potent smooth muscle cell mitogen of macrophage origin. It is expressed in a highly regulated fashion in vascular endothelial and smooth muscle cells, indicating a potentially important role for this gene in atherosclerosis. In addition, the HB-EGF precursor has recently been found to function as a receptor for diphtheria toxin. Using an HB-EGF cDNA probe, we cloned the human gene encoding HB-EGF. The HB-EGF gene contains six exons and five intervening sequences spanning 14 kb of DNA. By primer extension and S1 nuclease analysis, we located a major transcription start site (corresponding to an A residue) 14 bp beyond the 5' end of the HB-EGF cDNA. There were no TATAAA or CCAAT consensus sequences upstream of the transcription start site. The density of primer extension bands generated by RNA from endothelial cells treated with tumor necrosis factor-alpha (TNF-alpha) was 10 times higher than that of bands generated by the control, indicating that TNF-alpha increased the level of HB-EGF mRNA. Using transient reporter gene transfection experiments, we show that 2.0 kb of HB-EGF 5'-flanking sequence has promoter activity in bovine aortic endothelial cells. By analysis of DNA isolated from human-mouse somatic hybrid cell lines, we assign the HB-EGF gene to chromosome 5. By functional study, chromosome 5 has been associated with diphtheria toxin susceptibility.