The trans-activation response DNA-binding protein TDP-43 regulates RNA processing and forms neuropathological aggregates in patients with amyotrophic lateral sclerosis and frontotemporal lobar degeneration. Investigating TDP-43 post-translational modifications, we discovered that K84 acetylation reduced nuclear import whereas K136 acetylation impaired RNA binding and splicing capabilities of TDP-43. Such failure of RNA interaction triggered TDP-43 phase separation mediated by the C-terminal low complexity domain, leading to the formation of insoluble aggregates with pathologically phosphorylated and ubiquitinated TDP-43. Confirming the results from site-directed mutagenesis, we succeeded to introduce authentic acetyl-lysine at the identified sites via amber suppression. [AcK84]TDP-43 showed cytoplasmic mislocalization and the aggregation propensity of [acK136]TDP-43 was confirmed. With newly developed antibodies, we found that the nuclear sirtuin SIRT1 can potently deacetylate [acK136]TDP-43. Moreover, SIRT1 reduced the aggregation propensity of [acK136]TDP-43. Thus, distinct lysine acetylations modulate nuclear import, RNA binding and phase separation of TDP-43, suggesting novel regulatory mechanisms for TDP-43 pathogenesis.

中文翻译：

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Sirtuin-1 敏感的 Lysine-136 乙酰化驱动 TDP-43 的相分离和病理聚集

反式激活反应 DNA 结合蛋白 TDP-43 调节 RNA 加工并在肌萎缩侧索硬化和额颞叶变性患者中形成神经病理学聚集体。研究 TDP-43 翻译后修饰，我们发现 K84 乙酰化减少了核输入，而 K136 乙酰化损害了 TDP-43 的 RNA 结合和剪接能力。这种 RNA 相互作用的失败触发了由 C 端低复杂结构域介导的 TDP-43 相分离，导致形成具有病理性磷酸化和泛素化 TDP-43 的不溶性聚集体。确认定点诱变的结果，我们成功地通过琥珀抑制在确定的位点引入了真实的乙酰赖氨酸。[AcK84]TDP-43 显示细胞质错误定位，[acK136]TDP-43 的聚集倾向得到证实。使用新开发的抗体，我们发现核沉默调节蛋白 SIRT1 可以有效地去乙酰化 [acK136] TDP-43。此外，SIRT1 降低了 [acK136]TDP-43 的聚集倾向。因此，不同的赖氨酸乙酰化调节 TDP-43 的核输入、RNA 结合和相分离，表明 TDP-43 发病机制的新调控机制。