Project description:Massive numbers of modified bases in mRNAs sculpt the epitranscriptome and play vital roles in RNA metabolism. The only known acetylated RNA modification, N-4-acetylcytidine (ac4C), is highly conserved across cell types and among species. Although the GCN5-related acetyltransferase 10 (NAT10) functions as an ac4C writer, the mechanism underlying the acetylation process is largely unknown. In this study, we identified the NAT10/PCBP/TDP43 complex as an mRNA ac4C writer in mammalian cells. We identified RNA-binding proteins (RBPs) affiliated with two different families, PCBP1/2 (poly(rC)-binding protein 1/2) and TDP43 (TAR DNA binding protein 43), as NAT10 adaptors for mRNA tethering and substrate selection. Knockdown of the adaptors resulted in decreased mRNA acetylation abundance in HEK293T cells, with globally reduced density in 5`-untranslated region (UTR) and coding sequence (CDS) and ablated cytidine-rich ac4C motifs. The adaptors also affect the ac4C sites by recruiting NAT10 to their binding sequences. The presence of the NAT10/PCBP/TDP43 complex in mouse testes highlights its potential physiological functions in vivo. These findings reveal the composition of the mRNA ac4C writer complex in mammalian cells and expand our knowledge of mRNA acetylation and ac4C site preferences.
Project description:Massive numbers of modified bases in mRNAs sculpt the epitranscriptome and play vital roles in RNA metabolism. The only known acetylated RNA modification, N-4-acetylcytidine (ac4C), is highly conserved across cell types and among species. Although the GCN5-related acetyltransferase 10 (NAT10) functions as an ac4C writer, the mechanism underlying the acetylation process is largely unknown. In this study, we identified the NAT10/PCBP/TDP43 complex as an mRNA ac4C writer in mammalian cells. We identified RNA-binding proteins (RBPs) affiliated with two different families, PCBP1/2 (poly(rC)-binding protein 1/2) and TDP43 (TAR DNA binding protein 43), as NAT10 adaptors for mRNA tethering and substrate selection. Knockdown of the adaptors resulted in decreased mRNA acetylation abundance in HEK293T cells, with globally reduced density in 5`-untranslated region (UTR) and coding sequence (CDS) and ablated cytidine-rich ac4C motifs. The adaptors also affect the ac4C sites by recruiting NAT10 to their binding sequences. The presence of the NAT10/PCBP/TDP43 complex in mouse testes highlights its potential physiological functions in vivo. These findings reveal the composition of the mRNA ac4C writer complex in mammalian cells and expand our knowledge of mRNA acetylation and ac4C site preferences.
2024-12-27 | GSE252075 | GEO
Project description:PCBP1/2 and TDP43 Function As NAT10 Adaptors In ac4C Writer Complex Towards mRNAs in Mammalian Cells_293T_acRIP
Project description:N4-acetylcytidine (ac4C), a conserved but recently rediscovered RNA modification on tRNAs, rRNAs and mRNAs, is catalyzed by N-acetyltransferase 10 (NAT10). Lysine acylation is a ubiquitous protein modification that controls protein functions. Our latest study demonstrates a NAT10-dependent ac4C modification, which occurs on the polyadenylated nuclear RNA (PAN) encoded by oncogenic DNA virus Kaposi's sarcoma-associated herpesvirus (KSHV), can induce KSHV reactivation from latency and activate inflammasome. However, it remains unclear whether a novel lysine acylation occurs in NAT10 during KSHV reactivation and how this acylation of NAT10 regulates tRNAs ac4C modification. Here, we showed that NAT10 was lactylated by α-tubulin acetyltransferase 1 (ATAT1), as a writer at the critical domain, to exert RNA acetyltransferase function and thus increase the ac4C level of tRNASer-CGA-1-1. Mutagenesis at the ac4C site in tRNASer-CGA-1-1 inhibited its ac4C modifications, translation efficiency of viral lytic genes, and virion production. Mechanistically, KSHV PAN orchestrated NAT10 and ATAT1 to enhance NAT10 lactylation, resulting in tRNASer-CGA-1-1 ac4C modification, eventually boosting KSHV reactivation. Our findings reveal a novel post-translational modification in NAT10, as well as expand the understanding about tRNA-related ac4C modification during KSHV replication, which may be exploited to design therapeutic strategies for KSHV-related diseases.
Project description:RNA modification represents an important post-transcriptional regulatory mechanism in acute myeloid leukemia (AML). Given that the critical function of ac4C in control RNA translation, we sought to investigate the global impact of ac4C on protein expression. To this end, we conducted tandem mass tag (TMT) labeling and quantitative proteomics in MOLM13 AML cells with or without the ac4c writer NAT10 silencing.
Project description:Mammalian oocyte maturation is driven by strictly translational regulation of maternal mRNAs stored in the cytoplasm. However, the function and mechanism of post-transcriptional chemical modifications especially the newly identified N4-acetylcytidine (ac4C) catalyzed by N-acetyltransferase 10 (NAT10) in this process are previously unknown. In this study, we developed a low-input ac4C sequencing technology - ac4C LACE-seq and mapped 8241 ac4C peaks at the whole transcriptome level using 50 mouse oocytes at the germinal vesicle (GV) stage. We profiled the mRNA landscapes of NAT10-interactions and ac4C modifications. The NAT10-interacted and ac4C modified transcripts displayed association with high translation efficiency in oocytes. Oocyte-specific Nat10 knockout wiped out ac4C signals in oocytes and caused severe defects in meiotic maturation and female infertility. ac4C LACE-seq results indicated that Nat10 deletion led to a failure of ac4C deposition on mRNAs encoding key maternal factors such as MAY2, ZAR1, BTG4 and cyclin B1 that regulate transcriptome stability and maternal-to-zygotic transition. Nat10-deleted oocytes had decreased mRNA translation efficiencies during meiotic maturation, partially due to the direct inhibition ac4C sites on specific transcripts. In sum, we developed low-input, high-sensitivity mRNA ac4C profiling approach and highlighted the important physiological function of ac4C in precise regulation of the oocyte meiotic maturation by enhancing translation efficiency.
Project description:Mammalian oocyte maturation is driven by strictly translational regulation of maternal mRNAs stored in the cytoplasm. However, the function and mechanism of post-transcriptional chemical modifications especially the newly identified N4-acetylcytidine (ac4C) catalyzed by N-acetyltransferase 10 (NAT10) in this process are previously unknown. In this study, we developed a low-input ac4C sequencing technology—ac4C LACE-seq and mapped 8241 ac4C peaks at the whole transcriptome level using 50 mouse oocytes at the germinal vesicle (GV) stage. We profiled the mRNA landscapes of NAT10-interactions and ac4C modifications. The NAT10-interacted and ac4C modified transcripts displayed association with high translation efficiency in oocytes. Oocyte-specific Nat10 knockout wiped out ac4C signals in oocytes and caused severe defects in meiotic maturation and female infertility. ac4C LACE-seq results indicated that Nat10 deletion led to a failure of ac4C deposition on mRNAs encoding key maternal factors such as MAY2, ZAR1, BTG4 and cyclin B1 that regulate transcriptome stability and maternal-to-zygotic transition. Nat10-deleted oocytes had decreased mRNA translation efficiencies during meiotic maturation, partially due to the direct inhibition ac4C sites on specific transcripts. In sum, we developed low-input, high-sensitivity mRNA ac4C profiling approach and highlighted the important physiological function of ac4C in precise regulation of the oocyte meiotic maturation by enhancing translation efficiency.
Project description:N4-acetylcytidine (ac4C) is a posttransciptional RNA modification regulating in various important bioprocess. However, the role in human cancer, especially lymph node metastasis, remains largely unknown. Here, we showed NAT10, as the only “writer” of ac4C mRNA modification, was highly expressed in HNSCC patients with lymph node metastasis. High NAT10 levels in lymph node of HNSCC patients predicted poor overall survival. Moreover, we found the high expression of NAT10 was positively upregulated by NRF1 transcription factor. Gain and loss-of-function displayed that NAT10 promoted cell metastasis in mice. Mechanistically, NAT10 induced ac4C modification of GLMP and stabilized its mRNA, which triggered the activation of MAPK/ERK signaling pathway. Lastly, the NAT10’s specific inhibitor Remodelin could inhibit HNSCC tumorigenesis via 4-NQO-induced murine tumor model and remodel the tumor microenvironment, including angiogenesis, CD8+ T cell and Treg recruitment. These results demonstrated that NAT10 promoted lymph node metastasis of HNSCC via ac4C-dependent stabilization of GLMP transcript, providing a potential epitranscriptomic-targeted therapeutic strategy for HNSCC.
Project description:RNA modification represents an important post-transcriptional regulatory mechanism in acute myeloid leukemia (AML), however the function and mechanism of RNA acetylation ac4C in AML remains elusive. Here, we report that NAT10, as the ac4C writing enzyme, plays a critical oncogenic function in AML and represents a promising therapeutic target for AML. To understand the mechanisms underlying the function of NAT10 as an RNA ac4C writer in AML, we profiled ac4C modification in the transcriptome of MOLM13 cells using a refined ac4C RNA immunoprecipitation and high throughput sequencing (RacRIP-seq) protocol, and performed systematic calibration with a modification-free control library generated from the in vitro- transcribed MOLM13 transcriptome (referred to as IVT control) to eliminate most of the false- positive signals. We also applied the RacRIP-seq in NAT10 knockdown and control MOLM13 cells to characterize NAT10 targets.
Project description:N4-acetylcytidine (ac4C), a newly identified epigenetic modification within mRNAs, has been characterized as a crucial regulator of mRNA stability and translation efficiency. And NAT10 is the only known RNA acetyltransferase. In our study, we documented the down-regulated expression of both ac4C and NAT10 during meiotic maturation of mouse oocytes. NAT10 knockdown resulted in ac4C reduction and impaired mouse oocyte maturation in vitro. These results indicated that NAT10-mediated ac4C modification plays a critical regulatory role in oocyte meiotic maturation. We further performed high-throughput sequencing with NAT10-overexpressed HEK293T cells and NAT10-binding transcripts to investigate the genes modulated by NAT10-mediated ac4C modification.