Project description:Several prior reports have demonstrated that the epitranscriptomic addition of m6A to viral transcripts promotes the replication and pathogenicity of a wide range of viruses yet the underlying mechanism(s) causing this positive effect has remained unclear. It is known that m6A function is largely mediated by cellular m6A binding proteins or readers, however, how these m6A reader proteins contribute to the regulation of HIV-1 gene expression has remained controversial. Here, we confirm that m6A indeed enhances HIV-1 gene expression. We demonstrate that this effect is collectively mediated by the cytoplasmic reader YTHDF2, which increases HIV-1 transcript stability, and the nuclear m6A reader YTHDC1, which binds HIV-1 RNA at 7 distinct m6A methylated sites, regulating viral transcript alternative splicing.
Project description:Several prior reports have demonstrated that the epitranscriptomic addition of m6A to viral transcripts promotes the replication and pathogenicity of a wide range of viruses yet the underlying mechanism(s) causing this positive effect has remained unclear. It is known that m6A function is largely mediated by cellular m6A binding proteins or readers, however, how these m6A reader proteins contribute to the regulation of HIV-1 gene expression has remained controversial. Here, we confirm that m6A indeed enhances HIV-1 gene expression. We demonstrate that this effect is collectively mediated by the cytoplasmic reader YTHDF2, which increases HIV-1 transcript stability, and the nuclear m6A reader YTHDC1, which binds HIV-1 RNA at 7 distinct m6A methylated sites, regulating viral transcript alternative splicing.
Project description:In this study we performed MeRIP-Seq to study N6-methyl adenosine (m6A) and and N6,2′ -O-dimethyladenosine (m6Am) modification of mRNA. We investigated the effect of the microbiota on the transcriptome and epitranscriptomic modifications in murine liver and cecum. We compared m6A/m modification profiles in cecum of conventionally raised (CONV) and germ-free (GF) mice. We additionally included GF mice colonised with the flora of CONV mice for four weeks (ex-GF), for which show that they exhibit similar patterns of the most abundant genera of gut bacteria as CONV mice. We added mice treated with several antibiotics to deplete the gut flora (abx)and vancomycin treated mice in which the genera Akkermansia, Escherichia/Shigella and Lactobacillus were enriched. Furthermore, we included GF mice colonised with the commensal bacterium Akkermansia muciniphila (Am), Lactobacillus plantarum (Lp) and Escherichia coli Nissle (Ec) and analysed their m6A/m modification profiles. In addition, we analysed changes in m6A/m- modified liver RNA for CONV, GF, and Am, Lp and Ec mice.
Project description:Total RNA samples from human bronchial epithelial BEAS-2B passage-matched control cells and Cr(VI)-transofmred BEAS-2B cells were submitted to ArraySatr for total RNA m6A epitranscriptomic microarray analysis
Project description:Gut microbiota and their metabolites influence host gene expression and physiological status through diverse mechanisms. Here we investigate how gut microbiota and their metabolites impact host′s mRNA m6A epitranscriptome in various antibiotic-induced microbiota dysbiosis models. With multi-omics analysis, we find that the imbalance of gut microbiota can rewire host mRNA m6A epitranscriptomic profiles in brain, liver and intestine. We further explore the underlying mechanisms regulating host mRNA m6A methylome by depleting the microbiota with ampicillin. Metabolomic profiling shows that cholic acids are the main down-regulated metabolites with Firmicutes as the most significantly reduced genus in ampicillin-treated mice comparing to untreated mice. Fecal microbiota transplantations in germ-free mice and metabolites supplementations in cells verify that cholic acids are associated with host mRNA m6A epitranscriptomic rewiring. Collectively, this study employs an integrative multi-omics analysis to demonstrate the impact of gut microbiota dysbiosis on host mRNA m6A epitranscriptomic landscape via cholic acid metabolism.
Project description:N⁶-methyladenosine (m6A) and its reader, writer, and eraser (RWE) proteins assume crucial roles in regulating the splicing, stability, and translation of mRNA. To our knowledge, no systematic investigations have been conducted about the crosstalk between m6A and other modified nucleosides in RNA. Herein, we modified our recently established liquid chromatography-parallel-reaction monitoring (LC-PRM) method by incorporating stable isotope-labeled (SIL) peptides as internal or surrogate standards for profiling epitranscriptomic RWE proteins. We were able to detect reproducibly a total of 114 RWE proteins in HEK293T cells with the genes encoding m6A eraser proteins (i.e., ALKBH5, FTO) and the catalytic subunit of the major m6A writer complex (i.e., METTL3) being individually ablated. Notably, eight proteins were altered by more than 1.5-fold in the opposite directions in HEK293T cells depleted of METTL3 and ALKBH5. Analysis of published m6A mapping results revealed the presence of m6A in the corresponding mRNAs of four of these proteins. Together, we integrated SIL peptides into our LC-PRM method for quantifying epitranscriptomic RWE proteins, and our work revealed potential crosstalks between m6A and other epitranscriptomic modifications. Our modified LC-PRM method with the use of SIL peptides should be applicable for high-throughput profiling of epitranscriptomic RWE proteins in other cell types and in tissues.
Project description:Gut microbiota and their metabolites influence host gene expression and physiological status through diverse mechanisms. Here we investigate how gut microbiota and their metabolites impact host's mRNA m6A epitranscriptome in various antibiotic-induced microbiota dysbiosis models. With multi-omics analysis, we find that the imbalance of gut microbiota can rewire host mRNA m6A epitranscriptomic profiles in brain, liver and intestine. We further explore the underlying mechanisms regulating host mRNA m6A methylome by depleting the microbiota with ampicillin. Metabolomic profiling shows that cholic acids are the main down-regulated metabolites with Firmicutes as the most significantly reduced genus in ampicillin-treated mice comparing to untreated mice. Fecal microbiota transplantations in germ-free mice and metabolites supplementations in cells verify that cholic acids are associated with host mRNA m6A epitranscriptomic rewiring. Collectively, this study employs an integrative multi-omics analysis to demonstrate the impact of gut microbiota dysbiosis on host mRNA m6A epitranscriptomic landscape via cholic acid metabolism.