Temporal self-regulation of transposition through host-independent transposase rodlet formation.
Temporal self-regulation of transposition through host-independent transposase rodlet formation.
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DOI：
10.1093/nar/gkw1115
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发表时间：
2017-01-09
影响因子：
14.9
通讯作者：
Wilson MH
中科院分区：
文献类型：
--
作者：
Woodard LE;Downes LM;Lee YC;Kaja A;Terefe ES;Wilson MH
转座子在真核基因组中非常丰富，但必须对其动员进行微调以维持宿主生物体的适应性并允许转座子传播。百分之四十的人类基因组由转座元件序列组成，最丰富的剪切粘贴转座子来自 hAT 超家族。我们发现，在将基因转移至成年小鼠后，以及在离体无细胞条件下，来自赤拟谷盗的 hAT 转座酶 TcBuster 在人类组织培养细胞中形成丝状结构或小杆，这表明小杆形成不需要宿主辅助因子或细胞结构。对人类细胞中带有 GFP 的小棒的延时成像显示，它们是在涉及融合和裂变的动态过程中快速形成的。我们延迟了转座子 DNA 的可用性，并发现在转座酶浓度足够高以致可见的转座酶小棒出现后，转座下降。结合玉米 Ac 元件的早期发现，这些结果通过证明转座酶蛋白结构的出现和活性转座的结束是同时发生的，从而深入了解转座酶过量产生的抑制，这种效应对基因工程和水平基因转移具有影响。
Transposons are highly abundant in eukaryotic genomes, but their mobilization must be finely tuned to maintain host organism fitness and allow for transposon propagation. Forty percent of the human genome is comprised of transposable element sequences, and the most abundant cut-and-paste transposons are from the hAT superfamily. We found that the hAT transposase TcBuster from Tribolium castaneum formed filamentous structures, or rodlets, in human tissue culture cells, after gene transfer to adult mice, and ex vivo in cell-free conditions, indicating that host co-factors or cellular structures were not required for rodlet formation. Time-lapsed imaging of GFP-laced rodlets in human cells revealed that they formed quickly in a dynamic process involving fusion and fission. We delayed the availability of the transposon DNA and found that transposition declined after transposase concentrations became high enough for visible transposase rodlets to appear. In combination with earlier findings for maize Ac elements, these results give insight into transposase overproduction inhibition by demonstrating that the appearance of transposase protein structures and the end of active transposition are simultaneous, an effect with implications for genetic engineering and horizontal gene transfer.