LINE retrotransposition and host DNA repair machinery.
LINE retrotransposition and host DNA repair machinery.
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DOI：
10.1080/2159256x.2015.1096998
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发表时间：
2015-11
期刊：
影响因子：
--
通讯作者：
Okada N
中科院分区：
文献类型：
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作者：
Yamaguchi K;Kajikawa M;Okada N
长散布元件 (LINE) 或非长末端重复 (LTR) 反转录转座子是存在于大多数真核生物基因组 DNA 中的可移动遗传元件，包含宿主染色体的相当一部分。 LINEs构成内源诱变剂，引起宿主染色体插入突变，并对宿主基因组进化产生很大影响。然而，尽管 LINE 逆转录转座很重要，但其分子机制尚未完全了解。多项研究表明，参与 DNA 断裂修复的宿主蛋白可调节 LINE 逆转录转座。最近，我们提供的证据表明，有 2 种不同的途径（退火途径和直接途径）将 LINE 的 5' 端连接到宿主染色体 DNA。这些途径似乎被斑马鱼 LINE 和 DT40 细胞中的人类 L1 所独特使用。在 HeLa 细胞中，似乎仅使用退火途径。这意味着 2 个 LINE 的不同特征以及宿主因素决定了选择哪个途径。在这里，我们讨论了 LINE 逆转录转座的 5' 端连接途径，并提出 LINE 整合途径采用某些宿主修复因子。
Long interspersed elements (LINEs), or non-long-terminal repeat (LTR) retrotransposons, are mobile genetic elements that exist in the genomic DNA of most eukaryotes, comprising a considerable portion of the host chromosomes. LINEs constitute endogenous mutagens that cause insertional mutations in host chromosomes and have a large impact on host genome evolution. Despite their importance, however, the molecular mechanism of LINE retrotransposition is not fully understood. Several studies suggest that host proteins that participate in the repair of DNA breaks modulate LINE retrotransposition. Recently, we provided evidence that there are 2 distinct pathways—annealing and direct—that join the 5′-end of LINEs to host chromosomal DNA. These pathways appear to be used distinctively by zebrafish LINEs and the human L1 in DT40 cells. In HeLa cells, only the annealing pathway appears to be used. This implies that different characteristics of the 2 LINEs and also host factors dictate which pathway is selected. Here, we discuss the 5′-end-joining pathways of LINE retrotransposition and propose that the pathways of LINE integration adopt certain host repair factors.