Transfer RNA acetylation regulates in vivo mammalian stress signaling [tissues]
Ontology highlight
ABSTRACT: Transfer RNA (tRNA) modifications are crucial for protein synthesis, but their physiological roles remain poorly understood. Here we investigate the impact of N4-acetylcytidine (ac4C), a highly conserved tRNA modification, using a Thumpd1 knockout mouse model. We find that loss of Thumpd1-dependent tRNA acetylation leads to reduced levels of tRNALeu, increased ribosome stalling, and activation of eIF2α phosphorylation. Thumpd1 knockout mice exhibit growth defects and sterility. Remarkably, concurrent knockout of Thumpd1 and the stress-sensing kinase Gcn2 causes penetrant postnatal lethality, revealing a critical genetic interaction. Our findings demonstrate that a modification restricted to a single site within type II cytosolic tRNAs can regulate ribosome-mediated signaling in mammalian organisms. By providing insight into how tRNA modifications shape signaling and cell fate in response to stress, this work opens up novel strategies for therapeutic intervention and translational control.
Project description:Transfer RNA (tRNA) modifications are crucial for protein synthesis, but their physiological roles remain poorly understood. Here we investigate the impact of N4-acetylcytidine (ac4C), a highly conserved tRNA modification, using a Thumpd1 knockout mouse model. We find that loss of Thumpd1-dependent tRNA acetylation leads to reduced levels of tRNALeu, increased ribosome stalling and collisions, and activation of eIF2α phosphorylation. Thumpd1 knockout mice exhibit growth defects and sterility. Remarkably, concurrent knockout of Thumpd1 and the stress-sensing kinase Gcn2 causes penetrant postnatal lethality, revealing a critical genetic interaction. Our findings demonstrate that a modification restricted to a single site within type II cytosolic tRNAs can regulate ribosome-mediated signaling in mammalian organisms. By providing insight into how tRNA modifications shape signaling and cell fate in response to stress, this work opens up novel strategies for therapeutic intervention and translational control.
Project description:Transfer RNA (tRNA) modifications are crucial for protein synthesis, but their physiological roles remain poorly understood. Here we investigate the impact of N4-acetylcytidine (ac4C), a highly conserved tRNA modification, using a Thumpd1 knockout mouse model. We find that loss of Thumpd1-dependent tRNA acetylation leads to reduced levels of tRNALeu, increased ribosome stalling, and activation of eIF2α phosphorylation. Thumpd1 knockout mice exhibit growth defects and sterility. Remarkably, concurrent knockout of Thumpd1 and the stress-sensing kinase Gcn2 causes penetrant postnatal lethality, revealing a critical genetic interaction. Our findings demonstrate that a modification restricted to a single site within type II cytosolic tRNAs can regulate ribosome-mediated signaling in mammalian organisms. By providing insight into how tRNA modifications shape signaling and cell fate in response to stress, this work opens up novel strategies for therapeutic intervention and translational control.
Project description:Transfer RNA (tRNA) modifications are crucial for protein synthesis, but their physiological roles remain poorly understood. Here we investigate the impact of N4-acetylcytidine (ac4C), a highly conserved tRNA modification, using a Thumpd1 knockout mouse model. We find that loss of Thumpd1-dependent tRNA acetylation leads to reduced levels of tRNALeu, increased ribosome stalling and collisions, and activation of eIF2α phosphorylation. Thumpd1 knockout mice exhibit growth defects and sterility. Remarkably, concurrent knockout of Thumpd1 and the stress-sensing kinase Gcn2 causes penetrant postnatal lethality, revealing a critical genetic interaction. Our findings demonstrate that a modification restricted to a single site within type II cytosolic tRNAs can regulate ribosome-mediated signaling in mammalian organisms. By providing insight into how tRNA modifications shape signaling and cell fate in response to stress, this work opens up novel strategies for therapeutic intervention and translational control.
Project description:Transfer RNA (tRNA) modifications are crucial for protein synthesis, but their physiological roles remain poorly understood. Here we investigate the impact of N4-acetylcytidine (ac4C), a highly conserved tRNA modification, using a Thumpd1 knockout mouse model. We find that loss of Thumpd1-dependent tRNA acetylation leads to reduced levels of tRNALeu, increased ribosome stalling, and activation of eIF2-alpha phosphorylation. Thumpd1 knockout mice exhibit growth defects and sterility. Remarkably, concurrent knockout of Thumpd1 and the stress-sensing kinase Gcn2 causes penetrant postnatal lethality, revealing a critical genetic interaction. Our findings demonstrate that a modification restricted to a single position within type II cytosolic tRNAs can regulate ribosome-mediated signaling in mammalian organisms. Insights into how tRNA modifications shape phenotype and signaling in response to stress provide a foundation for novel strategies for therapeutic intervention and translational control.
Project description:N4 acetylcytidine (ac4C) modification mainly occurs on tRNA, rRNA, and mRNA, playing an important role in the expression of genetic information. However, it is still unclear whether microRNAs have undergone ac4C modification and their potential physiological and pathological functions. In this study, we identified that NAT10/THUMPD1 acetylates primary microRNAs (pri-miRNAs) with ac4C modification. Knockdown of NAT10 suppresses and augments the expression levels of mature miRNAs and pri-miRNAs, respectively. Molecular mechanism studies found that pri-miRNA ac4C promotes the processing of pri-miRNA into precursor miRNA (pre-miRNA) by enhancing the interaction of pri-miRNA and DGCR8, thereby increasing the biogenesis of mature miRNA. Knockdown of NAT10 attenuates the oncogenic characters of lung cancer cells by regulating miRNA production in cancers. Moreover, NAT10 is highly expressed in various clinical cancers and negatively correlated with poor prognosis. Thus, our results reveal that NAT10 plays a crucial role in cancer initiation and progression by modulating pri-miRNA ac4C to affect miRNA production, which would provide an attractive therapeutic strategy for cancers.
Project description:More researches have revealed that N4-acetylcytidine (ac4C) affected a variety of cellular and biological processes. In order to better understand the ac4C roles in biology and disease, we present an antibody-free, fluorine assisted metabolic sequencing method to detect RNA N4-acetylcytidine, called ‘FAM-seq’. We have successfully applied FAM-seq to profile ac4C landscapes in humans. By comparing with the classic ac4C antibody sequencing method, we demonstrated that FAM-seq is a convenient and specific method for transcriptome-wide detection of ac4C. This method holds promise to detect nascent RNA ac4C modifications.
Project description:NAT10-catalyzed N4-acetylcytidine (ac4C) has emerged as a vital post-transcriptional modulator on the coding transcriptome by promoting mRNA stability. To explore the transcriptome-wide profile of ac4C modification, we mapped the locations of ac4C modification on wild-type (WT) hESCs and NAT10 KD hESCs by NaCNBH3-based chemical ac4C sequencing (ac4C-seq).
Project description:NAT10-catalyzed N4-acetylcytidine (ac4C) has emerged as a vital post-transcriptional modulator on the coding transcriptome by promoting mRNA stability. To explore the transcriptome-wide profile of ac4C modification, we mapped the locations of ac4C modification on wild-type (WT) hESCs and NAT10 KD hESCs by high-throughput ac4C RNA immunoprecipitation sequencing (ac4C-RIP-seq).
Project description:Generation of the "epitranscriptome through post-transcriptional ribonucleoside modification embeds a layer of regulatory complexity into RNA structure and function. Here we describe N4-acetylcytidine (ac4C) as an mRNA modification that is catalyzed by the acetyltransferase NAT10. Transcriptome-wide mapping of ac4C revealed discretely acetylated regions that were enriched within coding sequences. Ablation of NAT10 reduced ac4C detection at the mapped mRNA sites and was globally associated with target mRNA down-regulation. Analysis of mRNA half-lives revealed a NAT10-dependent increase in stability in the cohort of acetylated mRNAs. mRNA acetylation was further demonstrated to enhance substrate translation in vitro and in vivo. Codon content analysis within ac4C peaks uncovered a biased representation of cytidine within wobble sites that was empirically determined to influence mRNA decoding efficiency. These findings expand the repertoire of mRNA modifications to include an acetylated residue and establish a role for ac4C in the regulation of mRNA translation. Generation of the “epitranscriptome” through post-transcriptional ribonucleoside modification embeds a layer of regulatory complexity into RNA structure and function. Here we describe N4-acetylcytidine (ac4C) as a novel mRNA modification that is catalyzed by the acetyltransferase NAT10. Transcriptome-wide mapping of ac4C revealed discretely acetylated regions that were distributed across target mRNAs with the majority of peaks occurring within coding regions. Depletion of ac4C through NAT10 ablation revealed a relationship to gene expression wherein loss of ac4C was globally associated with transcript downregulation. The presence of ac4C within coding sequences was associated with elevated ribosome density and enhanced translation, as assessed in vivo and in vitro. In addition to expanding the repertoire of mRNA modifications to include an acetylated residue, these findings highlight a role for ac4C in the control of mRNA metabolism at the level of translation.
Project description:N-acetyltransferase 10 (NAT10)-mediated N4-acetylcytidine (ac4C) modification is crucial for mRNA stability and translation efficiency, yet the underlying function in mammalian preimplantation embryos remains unclear.