A humanized yeast model reveals dominant-negative properties of neuropathy-associated alanyl-tRNA synthetase mutations.
A humanized yeast model reveals dominant-negative properties of neuropathy-associated alanyl-tRNA synthetase mutations.
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人源化酵母模型揭示了神经病相关丙氨酰-tRNA 合成酶突变的显性失活特性。
DOI：
10.1093/hmg/ddad054
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发表时间：
2023
影响因子：
3.5
通讯作者：
Antonellis,Anthony
中科院分区：
文献类型：
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作者：
Meyer-Schuman,Rebecca;Marte,Sheila;Smith,TylerJ;Feely,ShawnaME;Kennerson,Marina;Nicholson,Garth;Shy,MikeE;Koutmou,KristinS;Antonellis,Anthony
氨酰-tRNA合成酶（ARSs）是将tRNA分子连接到同源氨基酸的必需酶。六个ARS基因错义变异或小框内缺失的杂合性导致显性轴突性周围神经病变。这些致病性变体降低酶活性而不显著降低蛋白质水平，并且存在于编码同源二聚酶的基因中。这些观察结果提高了神经病相关ARS变体发挥显性负效应的可能性，将总体ARS活性降低到外周神经功能所需的阈值以下。为了测试这些变体的显性阴性特性，我们开发了一种人源化酵母试验，以共表达致病性人丙氨酰-tRNA合成酶（AARS 1）突变与野生型humanAARS 1。我们发现，多种功能丧失的AARS 1突变通过与野生型AARS 1的相互作用损害酵母生长，但减少这种相互作用拯救酵母生长。这表明，神经病相关的AARS 1变异发挥显性负效应，这支持了一个共同的，功能丧失的机制，为ARS介导的显性周围神经病变。
Aminoacyl-tRNA synthetases (ARSs) are essential enzymes that ligate tRNA molecules to cognate amino acids. Heterozygosity for missense variants or small in-frame deletions in six ARS genes causes dominant axonal peripheral neuropathy. These pathogenic variants reduce enzyme activity without significantly decreasing protein levels and reside in genes encoding homo-dimeric enzymes. These observations raise the possibility that neuropathy-associated ARS variants exert a dominant-negative effect, reducing overall ARS activity below a threshold required for peripheral nerve function. To test such variants for dominant-negative properties, we developed a humanized yeast assay to co-express pathogenic human alanyl-tRNA synthetase (AARS1) mutations with wild-type humanAARS1. We show that multiple loss-of-functionAARS1mutations impair yeast growth through an interaction with wild-typeAARS1, but that reducing this interaction rescues yeast growth. This suggests that neuropathy-associatedAARS1variants exert a dominant-negative effect, which supports a common, loss-of-function mechanism for ARS-mediated dominant peripheral neuropathy.