Intellectual disability-associated gene ftsj1 is responsible for 2′-O-methylation of specific tRNAs
Intellectual disability-associated gene ftsj1 is responsible for 2′-O-methylation of specific tRNAs
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DOI：
10.15252/embr.202050095
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发表时间：
2020-06-18
期刊：
影响因子：
7.7
通讯作者：
Liu, Ru-Juan
中科院分区：
文献类型：
--
作者：
Li, Jing;Wang, Yan-Nan;Liu, Ru-Juan
tRNA在反密码子环上的修饰对于准确解码至关重要。FTSJ1被假设为人类tRNA 2 '- o -甲基转移酶。突变为inftsj1的智力残疾患者的tRNA(Phe)（GAA）在C32和G34 （Cm32和Gm34）缺乏2 '- o -甲基化。然而，FTSJ1的催化活性、RNA底物和致病机制仍然未知，部分原因是体外重建酶活性的困难。在这里，我们鉴定了FTSJ1， WDR6的相互作用蛋白。我们首次在体外重建了FTSJ1-WDR6复合物的2 '- o -甲基化活性，该活性以m(1)G37为先决条件发生在特定tRNAs的34位。我们发现位置32、34和37的修饰是相互依赖的，并且在体内以等级顺序发生。我们还发现，在tsj1敲除细胞中，tRNA(Phe)（GAA）解码的UUC密码子的翻译效率降低，而不是uu密码子的翻译效率。生物信息学分析显示，近40%的高ttt偏倚基因与大脑/神经功能有关。我们的数据有可能增强我们对FTSJ1与神经系统发育之间关系的理解。
tRNA modifications at the anti-codon loop are critical for accurate decoding. FTSJ1 was hypothesized to be a human tRNA 2 '-O-methyltransferase. tRNA(Phe)(GAA) from intellectual disability patients with mutations inftsj1lacks 2 '-O-methylation at C32 and G34 (Cm32 and Gm34). However, the catalytic activity, RNA substrates, and pathogenic mechanism of FTSJ1 remain unknown, owing, in part, to the difficulty in reconstituting enzymatic activityin vitro. Here, we identify an interacting protein of FTSJ1, WDR6. For the first time, we reconstitute the 2 '-O-methylation activity of the FTSJ1-WDR6 complexin vitro, which occurs at position 34 of specific tRNAs with m(1)G37 as a prerequisite. We find that modifications at positions 32, 34, and 37 are interdependent and occur in a hierarchical orderin vivo. We also show that the translation efficiency of the UUU codon, but not the UUC codon decoded by tRNA(Phe)(GAA), is reduced inftsj1knockout cells. Bioinformatics analysis reveals that almost 40% of the high TTT-biased genes are related to brain/nervous functions. Our data potentially enhance our understanding of the relationship between FTSJ1 and nervous system development.