The non-autonomous retrotransposon SVA is trans-mobilized by the human LINE-1 protein machinery.
The non-autonomous retrotransposon SVA is trans-mobilized by the human LINE-1 protein machinery.
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DOI：
10.1093/nar/gkr863
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发表时间：
2012-02
影响因子：
14.9
通讯作者：
Schumann GG
中科院分区：
文献类型：
--
作者：
Raiz J;Damert A;Chira S;Held U;Klawitter S;Hamdorf M;Löwer J;Strätling WH;Löwer R;Schumann GG
SINE-VNTR-Alu (SVA) 元件是非自主的、原始人特异性的非 LTR 反转录转座子，其组织结构为复合移动元件。它们代表了进化上最年轻、目前活跃的人类非 LTR 反转录转座子家族，并且偶尔产生致病插入。由于预先存在的基因组 SVA 序列具有长散布元件 1 (LINE-1, L1) 介导的逆转录转座的结构特征，因此多年来一直假设 SVA 元件是由 L1 蛋白机制进行反式动员的。为了检验这一假设，我们使用三种不同的人类特异性 SVA 报告元件在细胞培养物中开发了 SVA 逆转录转座报告基因测定。我们证明，只有在 L1 编码蛋白 ORF1p 和 ORF2p 存在的情况下，SVA 元件才会在 HeLa 细胞中被动员。在 HeLa-HA 细胞中，SVA 转移速率超过假基因形成频率 12 至 300 倍，表明 SVA 元件是 L1 蛋白的首选底物。获得 AluSp 元件使 SVA 报告元件的转动员频率增加了约 25 倍。删除规范 SVA 报告元件的 (CCCTCT)n 重复序列和 Alu 样区域会导致 SVA 转运率显着减弱。 SVA 从头插入主要是全长的，优先发生在富含 G+C 的区域，并显示出 L1 介导的逆转录转座的所有特征，这些特征也在先前存在的基因组 SVA 插入中观察到。
SINE-VNTR-Alu (SVA) elements are non-autonomous, hominid-specific non-LTR retrotransposons and distinguished by their organization as composite mobile elements. They represent the evolutionarily youngest, currently active family of human non-LTR retrotransposons, and sporadically generate disease-causing insertions. Since preexisting, genomic SVA sequences are characterized by structural hallmarks of Long Interspersed Elements 1 (LINE-1, L1)-mediated retrotransposition, it has been hypothesized for several years that SVA elements are mobilized by the L1 protein machinery in trans. To test this hypothesis, we developed an SVA retrotransposition reporter assay in cell culture using three different human-specific SVA reporter elements. We demonstrate that SVA elements are mobilized in HeLa cells only in the presence of both L1-encoded proteins, ORF1p and ORF2p. SVA trans-mobilization rates exceeded pseudogene formation frequencies by 12- to 300-fold in HeLa-HA cells, indicating that SVA elements represent a preferred substrate for L1 proteins. Acquisition of an AluSp element increased the trans-mobilization frequency of the SVA reporter element by ~25-fold. Deletion of (CCCTCT)n repeats and Alu-like region of a canonical SVA reporter element caused significant attenuation of the SVA trans-mobilization rate. SVA de novo insertions were predominantly full-length, occurred preferentially in G+C-rich regions, and displayed all features of L1-mediated retrotransposition which are also observed in preexisting genomic SVA insertions.
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影响因子：
14.5
作者：
Hancks DC;Kazazian HH Jr
通讯作者：
Kazazian HH Jr
影响因子：
14.9
作者：
Belancio VP;Roy-Engel AM;Pochampally RR;Deininger P
通讯作者：
Deininger P
影响因子：
1.7
作者：
Jurka, J;Kapitonov, VV;Walichiewicz, J
通讯作者：
Walichiewicz, J
影响因子：
7
作者：
Costantini, M;Clay, O;Bernardi, G
通讯作者：
Bernardi, G
DOI：
10.1073/pnas.0831042100
发表时间：
2003-04-29
影响因子：
11.1
作者：
Brouha, B;Schustak, J;Kazazian, HH
通讯作者：
Kazazian, HH