Phase separation-deficient TDP43 remains functional in splicing
Phase separation-deficient TDP43 remains functional in splicing
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DOI：
10.1038/s41467-019-12740-2
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发表时间：
2019-10
影响因子：
16.6
通讯作者：
H. B. Schmidt;A. Barreau;R. Rohatgi
中科院分区：
文献类型：
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作者：
H. B. Schmidt;A. Barreau;R. Rohatgi
固有无序区(IDR)是通常快速进化的低序列复杂性的蛋白质结构域，可以驱动相变，通常存在于许多与神经退行性疾病相关的蛋白质中，包括RNA处理因子TDP43。然而，相分离如何在细胞中对TDP43的生理功能做出贡献仍然是个谜。在这里，我们将进化序列分析指导的系统突变与TDP43相动力学的活细胞报告分析相结合，以确定IDR中由柔性亲水片段分隔的规则间隔的疏水基序是TDP43相性质的关键决定因素。该启发式框架允许定制TDP43冷凝物的材料属性，以确定对剪接功能的影响。值得注意的是，即使是在生理浓度下未能进行相分离的突变体，仍然可以有效地介导定量的单细胞剪接报告基因和内源性靶标的剪接。这表明TDP43的相分离能力并不是其剪接功能所必需的。
Intrinsically disordered regions (IDRs) are often fast-evolving protein domains of low sequence complexity that can drive phase transitions and are commonly found in many proteins associated with neurodegenerative diseases, including the RNA processing factor TDP43. Yet, how phase separation contributes to the physiological functions of TDP43 in cells remains enigmatic. Here, we combine systematic mutagenesis guided by evolutionary sequence analysis with a live-cell reporter assay of TDP43 phase dynamics to identify regularly-spaced hydrophobic motifs separated by flexible, hydrophilic segments in the IDR as a key determinant of TDP43 phase properties. This heuristic framework allows customization of the material properties of TDP43 condensates to determine effects on splicing function. Remarkably, even a mutant that fails to phase-separate at physiological concentrations can still efficiently mediate the splicing of a quantitative, single-cell splicing reporter and endogenous targets. This suggests that the ability of TDP43 to phase-separate is not essential for its splicing function.