Merlin G, van der Leede B J, McKune K, Knezevic N, Bannwarth W, Romquin N, Viegas-Pequignot E, Kiefer H, Aguet M, Dembic Z
INSERM U 365, Institut Curie, Paris, France.
Immunogenetics. 1997;45(6):413-21. doi: 10.1007/s002510050223.
In order to characterize the gene encoding the ligand binding (1(st); alpha) chain of the human IFN-gamma receptor, two overlapping cosmid clones were analyzed. The gene spans over 25 kilobases (kb) of the genomic DNA and has seven exons. The extracellular domain is encoded by exons 1 to 5 and by part of exon 6. The transmembrane region is also encoded by exon 6. Exon 7 encodes the intracellular domain and the 3' untranslated portion. The gene was located on chromosome 6q23.1, as determined by in situ hybridization. The 4 kb region upstream (5') of the gene was sequenced and analyzed for promoter activity. No consensus-matching TATA or CAAT boxes in the 5' region were found. Potential binding sites for Sp1, AP-1, AP-2, and CREB nuclear factors were identified. Compatible with the presence of the Sp1/AP-2 sites and the lack of TATA box, S1-nuclease mapping experiments showed multiple transcription initiation sites. Promoter activity of the 5' flanking region was analyzed with two different reporter genes: the Escherichia coli chloramphenicol acetyltransferase and human growth hormone. The smallest 5' region of the gene that still had full promoter activity was 692 base pairs in length. In addition, we found sequences belonging to the oldest family of Alu repeats, 2 - 3 kb upstream of the gene, which could be useful for genetic studies.
为了鉴定编码人γ干扰素受体配体结合（第1条；α）链的基因，对两个重叠的黏粒克隆进行了分析。该基因跨越基因组DNA的25千碱基（kb）以上，有7个外显子。细胞外结构域由外显子1至5以及外显子6的一部分编码。跨膜区域也由外显子6编码。外显子7编码细胞内结构域和3'非翻译部分。通过原位杂交确定该基因位于6号染色体q23.1上。对该基因上游（5'）4 kb区域进行测序并分析其启动子活性。在5'区域未发现与共有序列匹配的TATA或CAAT框。鉴定出了Sp1、AP-1、AP-2和CREB核因子的潜在结合位点。与Sp1/AP-2位点的存在以及TATA框的缺乏相一致，S1核酸酶图谱实验显示有多个转录起始位点。用两种不同的报告基因分析了5'侧翼区域的启动子活性：大肠杆菌氯霉素乙酰转移酶和人生长激素。该基因仍具有完整启动子活性的最小5'区域长度为692个碱基对。此外，我们在该基因上游2 - 3 kb处发现了属于最古老的Alu重复序列家族的序列，这可能对基因研究有用。
