一低剂量辐射诱导新基因的转录调控和初步功能分析  

cDNA cloning and transcriptional controlling of a novel low dose radiation-induced gene and its function analysis.

作　　者：周平坤[1] 隋建丽[1] 

机构地区：[1]北京放射医学研究所,100850

出　　处：《中华放射医学与防护杂志》2002年第2期73-76,共4页Chinese Journal of Radiological Medicine and Protection

基　　金：国家自然科学基金资助项目 (3 9870 2 14 );"十五"军队医学杰出中青年基金资助项目 (0 1J0 0 6);国家高技术研究发展计划(863 )资助项目 (2 0 0 1AA2 2 12 71)

摘　　要：目的　克隆低剂量辐射诱导基因 ,研究辐射对其转录调控作用和生物学功能。方法用mRNA差异显示技术分离辐射诱导表达基因 ,用RACE技术获取cDNA旁侧序列 ,Northern杂交分析基因的转录调节 ,生物信息学分析基因的结构和功能。结果　获得包括 3’端在内的辐射诱导新基因LRIGx的cDNA片段 ,序列同源性比较显示与人染色体 2 0q11 2 12一段DNA高度同源 (>99 % )。Northern杂交结果揭示该基因转录子全长约 8 5kb ,在 0 2Gy照射后 2h出现诱导表达 ,4h后转录子水平为对照细胞的 5倍多 ,也受 0 0 2Gy更低剂量照射诱导表达。 2Gy大剂量照射后 1h出现短暂诱导表达 ,但不如低剂量照射明显 ,2h后恢复正常水平。生物信息学分析结果显示该基因编码产物含有解旋酶活性保守区。结论　分离鉴定出一低剂量辐射反应基因 ,其编码蛋白可能参与DNA代谢 (如修复 )等细胞辐射反应过程。Objective\ To clone a novel low dose radiation\|induced gene (LRIGx) and study its function as well as its transcriptional changes after irradiation. Methods\ Its cDNA was obtained by DDRT\|PCR and RACE techniques.Northern blot hybridization was used to investigate the gene transcription.Bioinformatics was employed to analysis structure and function of this gene. Results\ LRIGx cDNA was cloned.The sequence of LRIGx was identical to a DNA clone located in human chromosome 20 q 11\^2\|12.Bioinformatics analysis predicted an encoded protein with a conserved helicase domain.Northern analysis revealed a ～8 5 kb transcript which was induced after 0 2 Gy as well as 0 02 Gy irradiation,and the transcript level was increased 5 times at 4 h after 0\^2 Gy irradiation.The induced level of LRIGx transcript by 2\^0 Gy high dose was lower than by 0 2 Gy. Conclusion\ A novel low dose radiation\|induced gene has been cloned.It encodes a protein with a conserved helicase domain that could involve in DNA metabolism in the cellular process of radiation response.\;

关 键 词：辐射诱导基因 转录调节 低剂量辐射 解旋酶 生物信息 辐射损伤 

分 类 号：R818[医药卫生—放射医学]