Hosoda K, Nakao K, Tamura N, Arai H, Ogawa Y, Suga S, Nakanishi S, Imura H
Department of Medicine, Kyoto University School of Medicine, Japan.
J Biol Chem. 1992 Sep 15;267(26):18797-804.
We have isolated and characterized the gene for the human endothelin-A receptor. Southern blot analyses demonstrated a single copy gene for the receptor. The gene spans more than 40 kilobases and contains eight exons and seven introns. Intron 1 exists in the 5'-noncoding region, and introns 2-7 occur in the coding region. The locations of introns 2-7 exist before or after the regions encoding the membrane-spanning domains. The transcription start site, determined by primer extension experiments, is 502 base pairs upstream of the methionine initiation codon. The 5'-flanking region lacks a typical TATA box but contains a potential SP-1-binding site 27 base pairs upstream of the transcription start site. Using human-rodent somatic hybrid cell DNA, the gene was assigned to human chromosome 4. Northern blot analyses revealed a 4.3-kilobase mRNA in a wide variety of human tissues, at the highest level in the aorta and at a substantial level in the cultured human mesangial cells. This is the first report of cloning of a gene for a member of the endothelin receptor family. The present study should give a clue to the discovery of possible disorders of the endothelin-A receptor, as well as facilitate the elucidation of the mechanisms by which the gene expression is regulated.
我们已经分离并鉴定了人类内皮素 - A受体基因。Southern印迹分析表明该受体基因是单拷贝基因。该基因跨度超过40千碱基，包含8个外显子和7个内含子。内含子1存在于5'非编码区，内含子2 - 7存在于编码区。内含子2 - 7的位置位于编码跨膜结构域的区域之前或之后。通过引物延伸实验确定的转录起始位点在甲硫氨酸起始密码子上游502个碱基对处。5'侧翼区缺乏典型的TATA盒，但在转录起始位点上游27个碱基对处含有一个潜在的SP - 1结合位点。利用人 - 啮齿类体细胞杂交细胞DNA，该基因被定位到人类第4号染色体上。Northern印迹分析显示在多种人类组织中存在一条4.3千碱基的mRNA，在主动脉中水平最高，在培养的人系膜细胞中也有相当水平的表达。这是内皮素受体家族成员基因克隆的首次报道。本研究应为发现内皮素 - A受体可能的疾病提供线索，并有助于阐明该基因表达调控的机制。
