The promoter of the chicken alpha 2(VI) collagen gene has features characteristic of house-keeping genes and of proto-oncogenes.
The promoter of the chicken alpha 2(VI) collagen gene has features characteristic of house-keeping genes and of proto-oncogenes.
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鸡α2(VI)胶原蛋白基因的启动子具有看家基因和原癌基因的特征。
作者：
E. Koller;A. Hayman;B. Trueb
鸡α 2（VI）胶原蛋白基因的启动子揭示了管家基因和生长控制相关基因的几个有趣特征。它不具有典型的TATAA或CAAT盒，但它含有几个转录因子Sp1和ETF的潜在结合位点。该基因的5'侧翼区域形成典型的“CpG岛”，其中二核苷酸序列CpG相对于主体基因组以高频率出现。与缺乏TATAA元件一致，该基因含有分布在75 bp基因组DNA上的多个转录起始位点。包含所有转录起始位点和整个CpG岛的短DNA片段（207 bp）在与异源报告基因连接时显示强启动子活性。该启动子的上游区域含有一个长的同型嘌呤/同型嘧啶元件（403 bp），该元件对核酸内切酶S1敏感。该元件可能具有采用分子内发夹三链体结构的能力，并且可以在α 2（VI）胶原基因座处的染色质组织中发挥作用。我们的研究结果表明，α 2（VI）胶原蛋白启动子的结构是完全不同的，从任何其他胶原蛋白启动子的特点，到目前为止。
The promoter of the chicken alpha 2(VI) collagen gene reveals several interesting features characteristic of house-keeping genes and growth control related genes. It does not possess a typical TATAA or CAAT box, but it contains several potential binding sites for transcription factors Sp1 and ETF. The 5' flanking region of the gene forms a typical 'CpG island' where the dinucleotide sequence CpG occurs with high frequency relative to the bulk genome. Consistent with the lack of a TATAA element, the gene contains multiple transcription initiation sites distributed over 75 bp of genomic DNA. A short DNA fragment (207 bp) encompassing all the transcription initiation sites and the entire CpG island shows strong promoter activity when linked to a heterologous reporter gene. The upstream region of the promoter harbours a long homopurine/homopyrimidine element (403 bp) which is sensitive to endonuclease S1. This element might have the ability to adopt an intramolecular hairpin triplex structure and could play a role in the organization of the chromatin at the alpha 2(VI) collagen locus. Our results demonstrate that the structure of the alpha 2(VI) collagen promoter is completely different from that of any other collagen promoter characterized so far.