摘要
Although the function of tRNAs in the translational process is well established,it remains controversial whether tRNA abundance is tightly associated with translational efficiency(TE)in mammals.Moreover,how critically the expression of tRNAs contributes to the establishment of tissue-specific proteomes in mammals has not been well addressed.Here,we measured both tRNA expression using demethylase-tRNA sequencing(DM-tRNA-seq)and TE of mRNAs using ribosome-tagging sequencing(RiboTag-seq)in the brain,heart,and testis of mice.Remarkable variation in the expression of tRNA isodecoders was observed among different tissues.When the statistical effect of isodecoder-grouping on reducing variations is considered through permutating the anticodons,we observed an expected reduction in the variation of anticodon expression across all samples,an unexpected smaller variation of anticodon usage bias,and an unexpected larger variation of tRNA isotype expression at amino acid level.Regardless of whether or not they share the same anticodons,the isodecoders encoding the same amino acids are co-expressed across different tissues.Based on the expression of tRNAs and the TE of mRNAs,we find that the tRNA adaptation index(tAI)and TE are significantly correlated in the same tissues but not between tissues;and tRNA expression and the amino acid composition of translating peptides are positively correlated in the same tissues but not between tissues.We therefore hypothesize that the tissue-specific expression of tRNAs might be due to post-transcriptional mechanisms.This study provides a resource for tRNA and translation studies,as well as novel insights into the dynamics of tRNAs and their roles in translational regulation.
基金
supported by the National Key R&D Program of China(Grant No.2018YFA0107200 to Jinkai Wang)
the National Natural Science Foundation of China(Grant Nos.31970594 and 31771446 to Jinkai Wang,Grant Nos.81922052 and 81974435 to Shuibin Lin
Grant No.31971335 to Dan Ohtan Wang)
the Natural Science Foundation of Guangdong,China(Grant No.2019B151502011 to Shuibin Lin
Grant No.2021A1515110650 to Yan Gao)
the China Postdoctoral Science Foundation(Grant No.2021M703755 to Yan Gao).
