Acetylation of nuclear localization signal controls importin-mediated nuclear transport of Ku70
Acetylation of nuclear localization signal controls importin-mediated nuclear transport of Ku70
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DOI：
10.1101/403485
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发表时间：
2018-08
期刊：
影响因子：
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通讯作者：
H. Fujimoto;T. Ikuta;A. Koike;M. Koike
中科院分区：
文献类型：
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作者：
H. Fujimoto;T. Ikuta;A. Koike;M. Koike
Ku70参与多种核内和核外过程。为了实现多功能控制，精确调节Ku70细胞内定位的机制是必不可少的。最近有报道称Ku70的乙酰化调节其功能。在这里，我们证明了Ku70中作为乙酰化靶点的特定赖氨酸残基对体内核转运的调节至关重要。Ku70- gfp融合蛋白在细胞核中短暂表达，而用谷氨酰胺取代赖氨酸残基来模拟Ku70核定位信号（NLS）中K553或K556的乙酰化，可显著降低Ku70的核定位。此外，在K553Q和K556Q突变体中，ku70输入蛋白的相互作用被抑制。理论估计表明，随着赖氨酸残基乙酰化，Ku70 NLS与输入蛋白α之间的结合能降低，类似于赖氨酸残基被谷氨酰胺取代的情况。这些结果表明，Ku70 NLS中特定赖氨酸残基的乙酰化是通过调节Ku70与核转运因子之间的相互作用来控制Ku70定位的关键开关。
Ku70 participates in various intra-and extra-nucleic processes. For multifunctional control, machinery that precisely regulates the intracellular localization of Ku70 is essential. Recently, it was reported that acetylation of Ku70 regulates its function. Here, we demonstrate that specific lysine residues in Ku70 that are targets of acetylation are critical for regulating nuclear transport in vivo. Ku70-GFP fusion proteins transiently expressed in cultured cells localized in the nucleus, whereas mimicking acetylation of K553 or K556 in the Ku70 nuclear localization signal (NLS) by substituting these lysine residues with glutamine markedly decreased the nuclear localization of Ku70. Moreover, the Ku70-importin interaction was suppressed in the K553Q and K556Q mutants. Theoretical estimations indicated that the binding energy between the Ku70 NLS and importin-α decreases with acetylation of lysine residues in the Ku70 NLS, similar to the case when these lysine residues are substituted with glutamine. These results suggest that acetylation of specific lysine residues in the Ku70 NLS is a key switch that controls the localization of Ku70 by modulating interactions between Ku70 and nuclear transport factors.