Deng Dehai,Qin Yichao,Lin Xiuying,Chu Meng,Lv Daizhu,Lin Huan
Background The oil palm ( Elaeis guineensis ) is a crucial agricultural commodity, yielding the highest oil output among oil-bearing crops. Despite its significance, productivity challenges persist due to genetic and environmental factors. This study breaks new ground by mapping tRNA modifications in oil palm, exploring their roles during fruit ripening, an area not extensively studied in non-model crops. Results Utilizing advanced RNA mass spectrometry techniques, we identified 48 distinct tRNA modifications across 88 sites, alongside 164 genes associated with tRNA modifying enzymes. This comprehensive mapping reveals the decreasing nature of most tRNA modifications during fruit development, except for adenosine 2’-O methylation (Am). It hints at a gradual weakening of protein translation quality control and highlights a unique role for Am during fruit ripening. Additionally, lipidomic analysis tracked 674 lipids in oil palm fruits, indicating a correlation between tRNA modifications and the accumulation of specific lipids. Conclusions This study mapped tRNA modifications in oil palm for the first time and showed the diversity of dynamic changes in tRNA modifications as the fruits develop.
Summary Cancer cells selectively promote translation of specific oncogenic transcripts to facilitate cancer survival and progression, but the underlying mechanisms are poorly understood. Here, we find that N 7 -methylguanosine (m 7 G) tRNA modification and its methyltransferase complex components, METTL1 and WDR4, are significantly upregulated in intrahepatic cholangiocarcinoma (ICC) and associated with poor prognosis. We further reveal the critical role of METTL1/WDR4 in promoting ICC cell survival and progression using loss- and gain-of-function assays in vitro and in vivo . Mechanistically, m 7 G tRNA modification selectively regulates the translation of oncogenic transcripts, including cell-cycle and epidermal growth factor receptor (EGFR) pathway genes, in m 7 G-tRNA-decoded codon-frequency-dependent mechanisms. Moreover, using overexpression and knockout mouse models, we demonstrate the crucial oncogenic function of Mettl1-mediated m 7 G tRNA modification in promoting ICC tumorigenesis and progression in vivo . Our study uncovers the important physiological function and mechanism of METTL1-mediated m 7 G tRNA modification in the regulation of oncogenic mRNA translation and cancer progression.
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