Hiz Semra, Kiliç Seval, Bademci Güney, Karakulak Tülay, Erdoğan Aybike, Özden Burcu, Eresen Çiğdem, Erdal Esra, Yiş Uluç, Tekin Mustafa, Karakülah Gökhan, Karaca Ezgi, Öztürk Mehmet
İzmir Biomedicine and Genome Center, İzmir, Turkey.
Department of Pediatrics, Faculty of Medicine, Dokuz Eylül University, İzmir, Turkey.
Turk J Biol. 2022 Dec 5;46(6):458-464. doi: 10.55730/1300-0152.2631. eCollection 2022.
Majority of 37 human aminoacyl tRNA synthetases have been incriminated in diverse, mostly recessive, genetic diseases. In accordance with this, we uncovered a novel homozygous valyl-tRNA synthetase 1 () gene variant, leading to p.T1068M mutation. As in the previously reported mutations, the affected individual harboring p.T1068M was experiencing a neurodevelopmental disorder with intractable seizures, psychomotor retardation, and microcephaly. To link this phenotypic outcome with the observed genotype, we structurally modeled human and interpreted p.T1068M within the spatial distribution of previously reported variants. As a result, we uncovered that p.T1068M is clustered with three other pathogenic mutations in a 15 amino acid long stretch of the VARS1 anticodon-binding domain. While forming a helix-turn-helix motif within the anticodon-binding domain, this stretch harbors one-fourth of the reported mutations. Here, we propose that these clustered mutations can destabilize the interactions between the anticodon-binding and the tRNA synthetase domains and thus hindering the optimal enzymatic activity of . We expect that the depiction of this mutation cluster will pave the way for the development of drugs, capable of alleviating the functional impact of these mutations.
37种人类氨酰-tRNA合成酶中的大多数已被证实与多种主要为隐性的遗传疾病有关。据此,我们发现了一种新的纯合缬氨酰-tRNA合成酶1(VARS1)基因变异,导致p.T1068M突变。与先前报道的VARS1突变一样,携带p.T1068M的受影响个体患有神经发育障碍,伴有难治性癫痫、精神运动发育迟缓及小头畸形。为了将这一表型结果与观察到的基因型联系起来,我们对人类VARS1进行了结构建模,并在先前报道的VARS1变体的空间分布内解释了p.T1068M。结果,我们发现p.T1068M与其他三个致病突变聚集在VARS1反密码子结合结构域的一段15个氨基酸长的区域内。在反密码子结合结构域内形成螺旋-转角-螺旋基序时,这段区域包含了四分之一已报道的VARS1突变。在此,我们提出这些聚集的突变会破坏反密码子结合结构域与tRNA合成酶结构域之间的相互作用,从而阻碍VARS1的最佳酶活性。我们期望对这个突变簇的描述将为开发能够减轻这些突变功能影响的药物铺平道路。