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DNA双链断裂(DNA double-strand breaks,DSBs)是双螺旋DNA分子的两条链在相对位置或相邻数个碱基处同时发生断裂的现象,是发生在基因组水平上最严重的DNA损伤形式之一。体内的修复系统会积极参与消除或修复损伤的DNA,以使遗传物质恢复到原有的状态;如果受损的DNA未得到及时、有效的修复或发生错误修复,则可能导致遗传突变和肿瘤发生。因此,正确的DSBs修复在维持生物体遗传稳定性方面发挥了重要的作用。
目前已知有两种机制参与DSBs的修复,一种是非同源性末端连接(non-homologous end joining,NHEJ)修复机制,此机制主要通过DNA连接酶的作用将断裂的DNA双链重新连接起来;另一种是同源重组(homologous recombination,HR)修复机制,此机制主要是利用DNA序列间的同源性来识别DSBs,而负责配对和重组的蛋白质因子并无序列特异性。NHEJ和HR这两种DSBs修复机制都是由多个修复蛋白参与,经过多步反应的复杂过程,共同维护细胞基因组的稳定性。
DNA双链断裂修复途径中重要的修复蛋白
Important DNA repair proteins in DNA double-strand break repair pathways
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摘要: DNA双链断裂修复是DNA损伤最主要的修复途径之一,修复基因可以修复DNA损伤,保持遗传信息的完整性,从而抑制肿瘤的发生。目前已知参与DNA双链断裂损伤修复的机制有两种——非同源性末端连接和同源重组修复机制。该文介绍了参与非同源末端连接和同源重组修复机制的几种重要的修复蛋白。Abstract: DNA double-strand break repair pathway is one of DNA damage repair pathways. DNA repair genes can repair DNA damage, maintain the integrity of the genetic information and inhibit the formation of tumors. There are two mechanisms—non-homologous end joining and homologous recombination to repair DNA double-strand break. In this review, an overview of important repair proteins of non-homologous end joining and homologous recombination pathways was introduced.
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Key words:
- DNA damage /
- DNA /
- recombinant /
- DNA repair /
- Non-homologous end joining /
- Homologous recombination
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