LINE-1 ORF1 protein enhances Alu SINE retrotransposition.
LINE-1 ORF1 protein enhances Alu SINE retrotransposition.
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LINE-1 ORF1 蛋白增强 Alu SINE 逆转录转座。
DOI：
10.1016/j.gene.2008.04.007
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发表时间：
2008
期刊：
影响因子：
3.5
通讯作者：
Roy-Engel,AstridM
中科院分区：
文献类型：
--
作者：
Wallace,Nicholas;Wagstaff,BradleyJ;Deininger,PrescottL;Roy-Engel,AstridM
逆转录元件贡献了人类基因组质量的三分之一以上。目前激活的LINE-1(L1)编码两种蛋白质(ORF1p和ORF2p)，这两种蛋白质都是逆转录转座所严格需要的。相反，非编码寄生正弦(Alu)似乎只需要L1 ORF2p来进行自己的扩增。这一要求以前是使用人体细胞组织培养检测系统(HeLa)确定的。由于HeLa可能表达功能性L1蛋白，因此可能低水平的内源性ORF1p是观察到的标记Alu动员所必需的。通过分别表达人(L1RP和LRE3)和啮齿动物(L1A102和L1Spa)L1来源的ORF1和ORF2蛋白，我们证明了ORF1表达载体的增加增强了标记Alu在HeLa细胞中的动员。此外，使用鸡成纤维细胞作为替代细胞培养来源，我们在本实验中证实了ORF1p对Alu动员不是严格要求的。支持我们在HeLa细胞中的观察，我们发现在培养的鸡细胞中补充ORF1p可以改善标记的Alu逆转录转座。我们假设L1 ORF1p在加强Alu RNA与其逆转录转座所需因子之间的相互作用方面起着直接或间接的作用。
Retroelements have contributed over one third of the human genome mass. The currently active LINE-1 (L1) codes for two proteins (ORF1p and ORF2p), both strictly required for retrotransposition. In contrast, the non-coding parasitic SINE (Alu) only appears to need the L1 ORF2p for its own amplification. This requirement was previously determined using a tissue culture assay system in human cells (HeLa). Because HeLa are likely to express functional L1 proteins, it is possible that low levels of endogenous ORF1p are necessary for the observed tagged Alu mobilization. By individually expressing ORF1 and ORF2 proteins from both human (L1RPand LRE3) and rodent (L1A102and L1spa) L1 sources, we demonstrate that increasing amounts of ORF1 expressing vector enhances tagged Alu mobilization in HeLa cells. In addition, using chicken fibroblast cells as an alternate cell culture source, we confirmed that ORF1p is not strictly required for Alu mobilization in our assay. Supporting our observations in HeLa cells, we find that tagged Alu retrotransposition is improved by supplementation of ORF1p in the cultured chicken cells. We postulate that L1 ORF1p plays either a direct or indirect role in enhancing the interaction between the Alu RNA and the required factors needed for its retrotransposition.