Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France.
Institute of Cell Biology, University of Bern, Bern, Switzerland.
Elife. 2018 Sep 18;7:e37927. doi: 10.7554/eLife.37927.
The domestication of transposable elements has repeatedly occurred during evolution and domesticated transposases have often been implicated in programmed genome rearrangements, as remarkably illustrated in ciliates. In , PiggyMac (Pgm), a domesticated PiggyBac transposase, carries out developmentally programmed DNA elimination, including the precise excision of tens of thousands of gene-interrupting germline Internal Eliminated Sequences (IESs). Here, we report the discovery of five groups of distant Pgm-like proteins (PgmLs), all able to interact with Pgm and essential for its nuclear localization and IES excision genome-wide. Unlike Pgm, PgmLs lack a conserved catalytic site, suggesting that they rather have an architectural function within a multi-component excision complex embedding Pgm. PgmL depletion can increase erroneous targeting of residual Pgm-mediated DNA cleavage, indicating that PgmLs contribute to accurately position the complex on IES ends. DNA rearrangements in constitute a rare example of a biological process jointly managed by six distinct domesticated transposases.
转座元件的驯化在进化过程中反复发生,驯化的转座酶常常与程序性基因组重排有关,这在纤毛类动物中得到了显著的体现。在 中,一种驯化的 PiggyBac 转座酶 PiggyMac (Pgm) 执行发育程序性的 DNA 消除,包括精确切除数万条中断基因的生殖系内消除序列 (IES)。在这里,我们报告了五组远缘 Pgm 样蛋白 (PgmLs) 的发现,它们都能够与 Pgm 相互作用,对其核定位和 IES 切除全基因组是必不可少的。与 Pgm 不同的是,PgmLs 缺乏保守的催化位点,这表明它们在包含 Pgm 的多组分切除复合物中具有结构功能。PgmL 耗尽会增加剩余 Pgm 介导的 DNA 切割的错误靶向,表明 PgmLs 有助于准确地将复合物定位在 IES 末端。 中的 DNA 重排是由六个不同的驯化转座酶共同管理的生物过程的罕见例子。