鸡端粒酶反转录酶启动子区克隆及序列分析

Cloning and Sequence Analysis of Chicken Telomerase Reverse Transcriptase Promoter Region

根据GenBank(AY505015)报道的鸡端粒酶反转录酶序列设计了1对特异性引物,以鸡淋巴瘤细胞(MDCC-MSB1)总核酸为模板进行PCR。PCR产物连接到pMD19-T载体进行测序,通过BLAST对GenBank进行同源性搜索,并用DNAMAN分子生物学软件进行分析。结果测得MDCC-MSB1启动子区全长为997 bp,其中G+C占50.78%。与国外报道的端粒酶反转录酶(AY505015)启动子区序列同源性为99.22%。与人端粒酶反转录酶启动子区相比:二者在起始密码子之前约250 bp均有1个E-box,但在chTERT启动子区新增加了4个c-Myb位点,而3个c-Ets2和WT1位点缺失,其他基序二者的分布基本相似。二者启动子区富含CpG岛,延伸到编码区。

According to the published nucleotide sequence of chTERT（chicken Telomerase Reverse Tran- scriptase）, a pair of primers were designed and total nucleic acids from MDCC-MSB1 cells were used as template for PCR. Then the products were linked into pMD19-T vector, cloned, sequenced and analyzed. The sequence of chTERT promoter region was 997bp, and the ratio of G ＋ C in the Genome was 50.78%. The homology of chTERT promoter region to that of sequences （AY505015） was 99.22% in the nucleotide. The transcription factor binding motifs in the chTERT promoter region were compared with that of hTERT promoter region and several c-Myb （cellular proto-oncogene mycloblastosis） sites were found associated with chTERT only and c-Ets-2 （cellular proto-oncogene erythroblast）and WT1 （Wilm＇s tumor 1 tumor suppressor） were associated with hTERT only.Both have one E-box at -250 bp, and the other transcription factor binding motifs are similar to each other. ChTERT and hTERT possess an extensive CpG island and extending well into the coding region. Results presented here should promote structure-function studies of chTERT, including methylation profiles and contribute to the comparative analysis of TERT expression and regulation making progress in defining the molecular mechanisms of cancer development.