Structure and expression of the TREX1 and TREX2 3′→5′ exonuclease genes
Structure and expression of the TREX1 and TREX2 3′→5′ exonuclease genes
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DOI：
10.1074/jbc.m010051200
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发表时间：
2001-05-04
影响因子：
4.8
通讯作者：
Perrino, FW
中科院分区：
文献类型：
--
作者：
Mazur, DJ;Perrino, FW
TREX 1和TREX 2基因编码哺乳动物3 '->5'核酸外切酶。使用逆转录-聚合酶链反应策略研究TREX基因在人细胞中的表达。我们的研究结果表明，TREX 1和TREX 2在所有测试的组织中表达，为这些基因在人类细胞中的表达提供了直接证据。使用cDNA末端的快速扩增来鉴定TREX基因的潜在转录起始位点以回收TREX转录物的5 '侧翼区。5 ′-侧翼序列表明转录起始于TREX 1开放阅读框（ORF）上游-140和-650碱基对以及TREX 2 ORF上游-623和-753碱基对的共有推定启动子。鉴定了新的TREX 1和TREX 2 cDNA，其含有由位于基因组DNA中TREX 1 ORF 5 ′端多达18个内切酶和TREX 2 ORF 5 ′端多达25个内切酶的外显子产生的蛋白质编码序列。这些新的cDNA和GenBank（TM）数据库中的序列表明，含有TREX 1和TREX 2 ORF的转录物是利用多种机制产生的，所述机制包括交替的启动子使用、交替的剪接和用于3 ′切割和多聚腺苷酸化的不同位点。这些初步研究揭示了TREX 1和TREX 2基因的结构和表达中以前未被认识到的复杂性。
The TREX1 and TREX2 genes encode mammalian 3'-->5' exonucleases. Expression of the TREX genes in human cells was investigated using a reverse transcription-polymerase chain reaction strategy. Our results show that TREX1 and TREX2 are expressed in all tissues tested, providing direct evidence for the expression of these genes in human cells. Potential transcription start sites are identified for the TREX genes using rapid amplification of cDNA ends to recover the 5'-flanking regions of the TREX transcripts. The 5'-flanking sequences indicate transcription initiation from consensus putative promoters identified -140 and -650 base pairs upstream of the TREX1 open reading frame (ORF) and -623 and -753 base pairs upstream of the TREX2 ORF. Novel TREX1 and TREX2 cDNAs are identified that contain protein-coding sequences generated from exons positioned in genomic DNA up to 18 kilobases 5' to the TREX1 ORF and up to 25 kilobases 5' to the TREX2 ORF. These novel cDNAs and sequences in the GenBank(TM) data base indicate that transcripts containing the TREX1 and TREX2 ORFs are produced using a variety of mechanisms that include alternate promoter usage, alternative splicing, and varied sites for 3' cleavage and polyadenylation. These initial studies have revealed previously unrecognized complexities in the structure and expression of the TREX1 and TREX2 genes.