An important role for RUNX3 in human L1 transcription and retrotransposition.
An important role for RUNX3 in human L1 transcription and retrotransposition.
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RUNX3 在人类 L1 转录和逆转录转座中发挥重要作用。
DOI：
10.1093/nar/gkg663
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发表时间：
2003
影响因子：
14.9
通讯作者：
KazazianJr,HaigH
中科院分区：
文献类型：
--
作者：
Yang,Nuo;Zhang,Lin;Zhang,Yue;KazazianJr,HaigH
LINE‐1s （longinterspersednucleareelement‐1）是丰富的非LTR逆转录转座子，占人类基因组的17%。人类L1 （L1Hs）的5 ‘非翻译区（5 ’ utr）包含一个鲜为人知的内部启动子。在这里，我们报告了在基于细胞培养的实验中，在5'UTR中一个假定的RUNX结构域位点（+83到+101）的突变减少了L1Hs的转录和反转录。外源表达RUNX3，而不是RUNX家族的另外两个成员RUNX1和RUNX2，增加了L1Hs的转录和反转录转位，否则，靶向RUNX3和显性阴性RUNX的sirna会减少L1Hs的转录和反转录转位。此外，使用抗RUNX3抗体的电泳迁移转移试验（EMSA）证实了RUNX3与其结合位点之间的特异性相互作用。有趣的是，RUNX3也可能通过另一个假定的RUNX位点（+526至+508）调节L1Hs 5'UTR的反义启动子活性，这是由RUNX因子的位点定向突变和外源表达所揭示的。我们的研究结果表明，RUNX3在L1Hs逆转录以及其5'UTR在正义和反义方向上的转录中发挥了重要作用，这有助于我们了解L1Hs逆转录的机制及其对邻近细胞基因表达的影响。
LINE‐1s (longinterspersednuclearelements‐1) are abundant non‐LTR retrotransposons that comprise 17% of the human genome. The 5′ untranslated region (5′UTR) of human L1 (L1Hs) houses a poorly understood internal promoter. Here we report that mutations at a putative runt‐domain transcription factor (RUNX) site (+83 to +101) in the 5′UTR decreased L1Hs transcription and retrotransposition in cell culture‐based assays. Exogenous expression of RUNX3, but not the other two RUNX family members, RUNX1 and RUNX2, increased L1Hs transcription and retrotransposition, which were otherwise decreased by siRNAs targeting RUNX3 and a dominant negative RUNX. Further more, the specific interaction between RUNX3 and its binding site was demonstrated by an electrophoretic mobility shift assay (EMSA) using an anti‐RUNX3 antibody. Interestingly, RUNX3 may also regulate the antisense promoter activity of L1Hs 5′UTR via another putative RUNX site (+526 to +508), as revealed by site‐directed mutations and exogenous expression of RUNX factors. Our results indicate an important role for RUNX3 in L1Hs retrotransposition as well as transcription from its 5′UTR in both sense and antisense directions, and they should contribute to our understanding of the mechanism underlying L1Hs retrotransposition and its impact on the expression of adjacent cellular genes.