Sequence Determinants of TDP-43 Ribonucleoprotein Condensate Formation and Axonal Transport in Neurons.
Sequence Determinants of TDP-43 Ribonucleoprotein Condensate Formation and Axonal Transport in Neurons.
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DOI：
10.3389/fcell.2022.876893
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发表时间：
2022
影响因子：
5.5
通讯作者：
中科院分区：
文献类型：
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TDP-43是一种在RNA代谢中具有多种功能的RNA结合蛋白，它的突变会导致肌萎缩侧索硬化症(ALS)，但目前尚不清楚RNA生物学缺陷是如何引发运动神经元退化的。TDP-43是核糖核蛋白(RNP)颗粒的主要成分，RNP颗粒是调节RNA剪接、mRNA运输和翻译的相分离生物分子凝聚体。ALS相关的TDP-43突变大多在低复杂性区域被发现，促进了液体到固体的异常相变，并损害了神经元中RNP转运颗粒的动态类液体特性和运动性。在这里，我们进行了ALS连锁突变和TDP-43变体的比较分析，以确定关键结构元素，芳香族和带电残基，这些是TDP-43RNP在神经元中运输和凝聚形成的关键决定因素。我们发现A315T和Q343R与疾病相关的突变和芳香族残基的替换在α-螺旋结构域和LAKS中显示出最严重的缺陷，显示出TDP-43RNP颗粒运输的严重缺陷，并损害了顺行和逆行运动。百灵鸟中苯丙氨酸残基中一个或两个的F313L和F313-6L/Y取代表明芳环对TDP-43RNP的运输是重要的。同样，W334F/L替换α-螺旋结构域上的色氨酸残基，会削弱TDP-43RNP的运动性(W334L)或顺行转运(W334F)。我们还表明，R293A和R293K突变，破坏了LCD中唯一的RGG，大大降低了TDP-43RNP颗粒的远程定向运输和净速度。在α-螺旋结构域两侧的无序区域，我们发现保守的GF/G和Sys基序的F283Y、F397Y或Y374F替换也可能通过改变疏水性而削弱顺行和/或逆行运动。同样，远离α螺旋结构域的无序区域中与肌萎缩侧索硬化症相关的突变也显示出顺行转运缺陷，这与之前的发现一致，但这些突变没有A315T和Q343R严重。总体而言，我们的发现表明，保守的α-螺旋结构域、LAKS中的苯丙氨酸残基和RGG基序是TDP-43RNP运输的关键决定因素，表明它们可能介导发动机和接头蛋白的有效招募。这些结果为肌萎缩侧索硬化症相关的TDP-43在轴突运输和稳态方面的缺陷提供了可能的机制。
Mutations in TDP-43, a RNA-binding protein with multiple functions in RNA metabolism, cause amyotrophic lateral sclerosis (ALS), but it is uncertain how defects in RNA biology trigger motor neuron degeneration. TDP-43 is a major constituent of ribonucleoprotein (RNP) granules, phase separated biomolecular condensates that regulate RNA splicing, mRNA transport, and translation. ALS-associated TDP-43 mutations, most of which are found in the low complexity domain, promote aberrant liquid to solid phase transitions and impair the dynamic liquid-like properties and motility of RNP transport granules in neurons. Here, we perform a comparative analysis of ALS-linked mutations and TDP-43 variants in order to identify critical structural elements, aromatic and charged residues that are key determinants of TDP-43 RNP transport and condensate formation in neurons. We find that A315T and Q343R disease-linked mutations and substitutions of aromatic residues within the α-helical domain and LARKS, show the most severe defects in TDP-43 RNP granule transport and impair both anterograde and retrograde motility. F313L and F313-6L/Y substitutions of one or both phenylalanine residues in LARKS suggest the aromatic rings are important for TDP-43 RNP transport. Similarly, W334F/L substitutions of the tryptophan residue in the α-helical domain, impair TDP-43 RNP motility (W334L) or anterograde transport (W334F). We also show that R293A and R293K mutations, which disrupt the only RGG in the LCD, profoundly reduce long-range, directed transport and net velocity of TDP-43 RNP granules. In the disordered regions flanking the α-helical domain, we find that F283Y, F397Y or Y374F substitutions of conserved GF/G and SYS motifs, also impair anterograde and/or retrograde motility, possibly by altering hydrophobicity. Similarly, ALS-linked mutations in disordered regions distant from the α-helical domain also show anterograde transport deficits, consistent with previous findings, but these mutations are less severe than A315T and Q343R. Overall our findings demonstrate that the conserved α-helical domain, phenylalanine residues within LARKS and RGG motif are key determinants of TDP-43 RNP transport, suggesting they may mediate efficient recruitment of motors and adaptor proteins. These results offer a possible mechanism underlying ALS-linked TDP-43 defects in axonal transport and homeostasis.
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影响因子：
16.6
作者：
Altman T;Ionescu A;Ibraheem A;Priesmann D;Gradus-Pery T;Farberov L;Alexandra G;Shelestovich N;Dafinca R;Shomron N;Rage F;Talbot K;Ward ME;Dori A;Krüger M;Perlson E
通讯作者：
Perlson E
影响因子：
5.6
作者：
Deshimaru M;Kinoshita-Kawada M;Kubota K;Watanabe T;Tanaka Y;Hirano S;Ishidate F;Hiramoto M;Ishikawa M;Uehara Y;Okano H;Hirose S;Fujioka S;Iwasaki K;Yuasa-Kawada J;Mishima T;Tsuboi Y
通讯作者：
Tsuboi Y
DOI：
10.1038/nrm3918
发表时间：
2015-02
期刊：
Nature reviews. Molecular cell biology
影响因子：
--
作者：
通讯作者：
--
影响因子：
4.8
作者：
Fuentealba, Rodrigo A.;Udan, Maria;Baloh, Robert H.
通讯作者：
Baloh, Robert H.
影响因子：
7
作者：
Elvira, G;Wasiak, S;Sossin, WS
通讯作者：
Sossin, WS