Target DNA chromatinization modulates nicking by L1 endonuclease
Target DNA chromatinization modulates nicking by L1 endonuclease
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DOI：
10.1093/nar/29.2.573
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发表时间：
2001-01-15
影响因子：
14.9
通讯作者：
Boeke, JD
中科院分区：
文献类型：
--
作者：
Cost, GJ;Golding, A;Boeke, JD
L1元件是通过RNA中间体复制的人类转座子。至少15%的人类基因组是由L1序列组成的。转位反应的一个重要的初始步骤是L1内切酶（L1 EN）对基因组DNA的刻蚀。在体内，大部分基因组以染色质的形式存在，或者正在进行转录、复制或修复等生化交易，这可能会改变L1转位机制对DNA的可及性。为了研究这种可能性，我们研究了底物染色化对L1 EN刻蚀DNA能力的影响。我们发现，整合到核小体中的DNA通常不易被L1 EN切割，有趣的是，当被纳入染色质中时，少数DNA序列的切割会增强，因此，染色质化等动态表观遗传因素可能会影响L1和其他逆转录因子在人类基因组中的相对永久位置。
L1 elements are human transposons which replicate via an RNA intermediate. At least 15% of the human genome is composed of L1 sequence. An important initial step in the transposition reaction is nicking of the genomic DNA by L1 endonuclease (L1 EN), In vivo much of the genome exists in the form of chromatin or is undergoing biochemical transactions such as transcription, replication or repair, which may alter the accessibility of the L1 transposition machinery to DNA, To investigate this possibility we have examined the effect of substrate chromatinization on the ability of L1 EN to nick DNA, We find that DNA incorporated into nucleosomes is generally refractory to nicking by L1 EN, Interestingly, nicking of a minority of DNA sequences is enhanced when included in chromatin, Thus, dynamic epigenetic factors such as chromatinization are likely to influence the relatively permanent placement of L1 and other retroelements in the human genome.