Wu Jianyu, Daino Kazuhiro, Ichimura Sachiko, Nenoi Mitsuru
Radiation Effect Mechanisms Research Group, National Institute of Radiological Sciences, Inage-ku, Chiba 263-8555, Japan.
Radiat Res. 2006 Nov;166(5):810-3. doi: 10.1667/RR0570.1.
Recent improvements in DNA microarray technologies and bioinformatics have made it possible to look for common features of ionizing radiation-responsive genes and their regulatory regions. We analyzed the promoters of 217 radiation-responsive human genes, compiled from microarray databases available in the literature. Using the DBTSS database, the transcriptional start sites were determined, and the core promoter elements, such as the TATA-box, initiator (Inr), GC-box and CCAAT-box, were searched for in the -1000 bp/ +200 bp region of each gene by using MATCH. It was found that the frequency of Inr in radiation-responsive genes was higher than that in general genes, and the frequencies of the GC-box and CCAAT-box were significantly lower than those in general genes. Use of the GC-box and the CCAAT-box in radiation-responsive genes was found to be dependent on the TATA-box status; that is, GC-box frequency was low in TATA box-containing genes, and CCAAT-box frequency was also low in TATA-less genes. When correlations between gene functions and frequencies of core promoter elements were examined, no apparent biased use of the core promoter element in association with a specific gene function was observed. It may be speculated that use of Inr in the core promoter correlates with appearance of radiation-responsive enhancer (silencer) elements in the upstream (downstream) regulatory region.
近期DNA微阵列技术和生物信息学的进步使得寻找电离辐射响应基因及其调控区域的共同特征成为可能。我们分析了从文献中可获得的微阵列数据库汇编的217个辐射响应人类基因的启动子。使用DBTSS数据库确定转录起始位点，并使用MATCH在每个基因的-1000 bp / +200 bp区域中搜索核心启动子元件，如TATA盒、起始子（Inr）、GC盒和CCAAT盒。结果发现，辐射响应基因中Inr的频率高于一般基因，而GC盒和CCAAT盒的频率明显低于一般基因。发现辐射响应基因中GC盒和CCAAT盒的使用取决于TATA盒状态；也就是说，含TATA盒的基因中GC盒频率较低，无TATA盒的基因中CCAAT盒频率也较低。当检查基因功能与核心启动子元件频率之间的相关性时，未观察到与特定基因功能相关的核心启动子元件的明显偏向使用。可以推测，核心启动子中Inr的使用与上游（下游）调控区域中辐射响应增强子（沉默子）元件的出现相关。
