In-depth Profiling of 4-hydroxy-2-nonenal Modification via Reversible Thiazolidine Chemistry
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo Sapiens
SUBMITTER: 
Haojie Lu
PROVIDER: PXD046404 | iProX | Thu Oct 26 00:00:00 BST 2023
REPOSITORIES: iProX
Similar Datasets
Project description:Internal bases in mRNA can be subjected to modifications that influence the fate of mRNA in cells. One of the most prevalent modified bases is found at the 5′ end of mRNA, at the first encoded nucleotide adjacent to the 7-methylguanosine cap. Here we show that this nucleotide, N6,2′-O-dimethyladenosine (m6Am), is a reversible modification that influences cellular mRNA fate. Using a transcriptome-wide map of m6Am we find that m6Am-initiated transcripts are markedly more stable than mRNAs that begin with other nucleotides. We show that the enhanced stability of m6Am-initiated transcripts is due to resistance to the mRNA-decapping enzyme DCP2. Moreover, we find that m6Am is selectively demethylated by fat mass and obesity-associated protein (FTO). FTO preferentially demethylates m6Am rather than N6-methyladenosine (m6A), and reduces the stability of m6Am mRNAs. Together, these findings show that the methylation status of m6Am in the 5′ cap is a dynamic and reversible epitranscriptomic modification that determines mRNA stability.
2016-12-21 | GSE78040 | GEO
Project description:N1-methyladenosine (m1A) is an abundant post-transcriptional RNA modification, yet little is known about its prevalence, topology and dynamics in mRNA. Here, we show that m1A is abundant in human mRNA, with an m1A/A ratio of ~0.02%. We develop m1A-ID-Seq, based on m1A immunoprecipitation and the inherent property of m1A to stall reverse transcription, for the transcriptome-wide m1A analysis. m1A-ID-Seq identifies 901 m1A peaks (from 583 genes) in mRNA and ncRNA, and reveals a prominent feature of enrichment in the 5â-untranslated region of mRNA transcripts, distinct from that of N6-methyladenosine, the most abundant internal mammalian mRNA modification. m1A in mRNA is also reversible by ALKBH3, a known DNA/RNA demethylase. Lastly, m1A responds dynamically to stimuli and hundreds of stress-induced m1A sites are identified. Collectively, our approaches allow comprehensive analysis of m1A methylation and provide an important tool for functional studies of potential epigenetic regulation via the reversible and dynamic m1A methylation. Identification of m1A sites in human embryonic kidney cells. Comparisons of m1A profiles of wild type HEK293T with ALKBH3 knock out cell line reveals the ALKBH3 specific sites. Stress inducible m1A sites are also identified by comparing the profiles of untreated cells with stress treated cells.
2016-02-05 | E-GEOD-73941 | biostudies-arrayexpress
Project description:Nucleotides on RNA are chemically modified during biogenesis of various mammalian RNA species and RNA modifications have profound effects on RNA function. The 2,2,7-trimethylguanosine modification of the 5′ of RNA molecules is one of the earliest discovered modified nucleotides on mammalian RNAs. Although the TMG cap is one of the most intensively studied RNA modifications, its distribution on a global scale has not been explored. In this study, the locations of the TMG cap on human RNA is determined, using RNA immunoprecipitation coupled with high-throughput sequencing. Although all prototypical modification sites were supported by this study, modification positions of some RNAs were erroneously annotated. In contrast to prototypic sites, many sites reported later were not validated at all. In addition to annotated modification sites, novel candidate sites were found on small Cajal body-specific RNAs.
2024-09-29 | GSE277971 | GEO
Project description:Nucleotides in RNA and DNA are chemically modified by numerous enzymes that alter their function. Eukaryotic ribosomal RNA (rRNA) is modified at more than 100 locations, particularly at highly conserved and functionally important nucleotides. During ribosome biogenesis, modifications are added at various stages of assembly. The existence of differently modified classes of ribosomes in normal cells is unknown because no method exists to simultaneously evaluate the modification status at all sites, within a single rRNA molecule. Using a combination of yeast genetics and nanopore direct RNA sequencing, we developed a reliable method to track the modification status of single rRNA molecules at 37 sites in 18S rRNA and 73 sites in 25S rRNA. We use our method to characterize patterns of modification heterogeneity and identify concerted modification of nucleotides found near functional centers of the ribosome. Distinct undermodified subpopulations of rRNAs accumulate upon loss of Dbp3 or Prp43 RNA helicases, suggesting overlapping roles in ribosome biogenesis. Modification profiles are surprisingly resistant to change in response to many genetic and environmental conditions that affect translation, ribosome biogenesis, and pre-mRNA splicing. The ability to capture single-molecule RNA modification profiles provides new insights into the roles of nucleotide modifications in RNA function.
2021-12-03 | GSE186634 | GEO
Project description:N1-Methyladenosine (m1A) is a prevalent post-transcriptional RNA modification, yet little is known about its abundance, topol- ogy and dynamics in mRNA. Here, we show that m1A is prevalent in Homo sapiens mRNA, which shows an m1A/A ratio of ~0.02%. We develop the m1A-ID-seq technique, based on m1A immunoprecipitation and the inherent ability of m1A to stall reverse tran- scription, as a means for transcriptome-wide m1A profiling. m1A-ID-seq identifies 901 m1A peaks (from 600 genes) in mRNA and noncoding RNA and reveals a prominent feature, enrichment in the 5' untranslated region of mRNA transcripts, that is dis- tinct from the pattern for N6-methyladenosine, the most abundant internal mammalian mRNA modification. Moreover, m1A in mRNA is reversible by ALKBH3, a known DNA/RNA demethylase. Lastly, we show that m1A methylation responds dynamically to stimuli, and we identify hundreds of stress-induced m1A sites. Collectively, our approaches allow comprehensive analysis of m1A modification and provide tools for functional studies of potential epigenetic regulation via the reversible and dynamic m1A methylation.
2016-02-05 | GSE73941 | GEO
Project description:N6-methyladenosine (m6A) is a widespread reversible chemical modification of RNAs, implicated in many aspects of RNA metabolism. Little quantitative information exists as to either how many transcript copies of particular genes are m6A modified (âm6A levelsâ), or the relationship of m6A modification(s) to alternative RNA isoforms. To deconvolute the m6A epitranscriptome, we developed m6A level and isoform-characterization sequencing (m6A-LAIC-seq). We found that cells exhibit a broad range of non-stoichiometric m6A levels with cell type specificity. At the level of isoform characterization, we discovered widespread differences in use of tandem alternative polyadenylation (APA) sites by methylated and nonmethylated transcript isoforms of individual genes. Strikingly, there is a strong bias for methylated transcripts to be coupled with proximal APA sites, resulting in shortened 3â untranslated regions (3â-UTRs), while nonmethylated transcript isoforms tend to use distal APA sites. m6A-LAIC-seq yields a new perspective on transcriptome complexity and links APA usage to m6A modifications. m6A-LAIC-seq of H1-ESC and GM12878 cell lines, each cell line has two replicates
2016-06-24 | E-GEOD-66086 | biostudies-arrayexpress
Project description:Protein lipidation is a post-translational modification that confers hydrophobicity on protein substrates to control their cellular localization, mediate protein trafficking, and regulate protein function. In particular, protein prenylation is a C-terminal modification on proteins bearing canonical motifs catalyzed by prenyltransferases. Prenylated proteins have been of interest due to their numerous associations with various diseases. Chemical proteomic approaches have been pursued over the last decade to define prenylated proteomes (prenylome) and probe their responses to perturbations in various cellular systems. Here, we describe the discovery of prenylation of a non-canonical prenylated protein, ALDH9A1, which lacks any apparent prenylation motif. This enzyme was initially identified through chemical proteomic profiling of prenylomes in various cell lines. Metabolic labeling with an isoprenoid probe using overexpressed ALDH9A1 revealed that this enzyme can be prenylated inside cells but does not respond to inhibition by prenyltransferase inhibitors. Site-directed mutagenesis of the key residues involved in ALDH9A1 activity indicates that the catalytic C288 bears the isoprenoid modification likely through an NAD+-dependent mechanism. Furthermore, the isoprenoid modification is also susceptible to hydrolysis, indicating a reversible modification. We hypothesize that this modification originates from endogenous farnesal or geranygeranial, the established degradation products of prenylated proteins and results in a thioester form that accumulates. This novel reversible prenoyl modification on ALDH9A1 expands the current paradigm of protein prenylation by illustrating a potentially new type of protein–lipid modification that may also serve as a novel mechanism for controlling enzyme function
2023-11-06 | PXD036365 | Pride
Project description:The dynamic modification of proteins by many metabolites suggests an intimate link between energy metabolism and post-translational modifications (PTM). For instance, starvation and low-carbohydrate diets lead to the accumulation of the ketone body, β-hydroxybutyrate (BHB), whose blood concentrations increase more than 10-fold into the millimolar range, concomitant with the accumulation of lysine β-hydroxybutyrylation (Kbhb) of proteins. As with other lysine acylations, Kbhb marks can be removed by histone deacetylases (HDACs). Here, we report that class I HDACs unexpectedly catalyze a reverse reaction that generates the Kbhb modification on target proteins. Through mutational analysis, we show a shared reliance on key active site amino acids for classical deacetylation and non-canonical HDAC-catalyzed β-hydroxybutyrylation. Based on these data, we propose that HDACs catalyze a condensation reaction between the free amine group on lysine and BHB, thereby generating the amide bond required for covalent attachment of BHB. Also consistent with reversible HDAC activity, Kbhb formation is driven by mass action and substrate availability. This reversible HDAC activity is not limited to BHB but also extends to multiple short-chain fatty acids and represents a novel mechanism of PTM deposition relevant to metabolically-sensitive proteome modifications.
2025-04-16 | PXD058840 | Pride
Project description:The RNA N6-methyladenosine (m6A) modification is a critical regulator of various biological processes, but precise and dynamic control of m6A remains a challenge. In this work, we present a red/far-red light-inducible m6A editing system that enables efficient and reversible modulation of m6A levels with minimal off-target effects. By engineering the CRISPR dCas13 protein and sgRNA with two pairs of light-inducible heterodimerizing proteins, ΔphyA/FHY1 and Bphp1/PspR2, we achieved targeted recruitment of m6A effectors. This system significantly enhances m6A writing efficiency, and allows dynamic regulation of m6A deposition and removal on specific transcripts, such as SOX2 and ACTB. Notably, reversible m6A editing was achieved through cyclic modulation at a single target site, demonstrating the ability to influence mRNA expression and modulate the differentiation state of human embryonic stem cells. This optogenetic platform offers a precise, versatile tool for cyclic and reversible m6A regulation, with broad implications for understanding RNA biology and its potential applications in research and medicine.
2025-03-26 | GSE285697 | GEO
Project description:N6-methyladenosine (m6A) is a widespread reversible chemical modification of RNAs, implicated in many aspects of RNA metabolism. Little quantitative information exists as to either how many transcript copies of particular genes are m6A modified (“m6A levels”), or the relationship of m6A modification(s) to alternative RNA isoforms. To deconvolute the m6A epitranscriptome, we developed m6A level and isoform-characterization sequencing (m6A-LAIC-seq). We found that cells exhibit a broad range of non-stoichiometric m6A levels with cell type specificity. At the level of isoform characterization, we discovered widespread differences in use of tandem alternative polyadenylation (APA) sites by methylated and nonmethylated transcript isoforms of individual genes. Strikingly, there is a strong bias for methylated transcripts to be coupled with proximal APA sites, resulting in shortened 3’ untranslated regions (3’-UTRs), while nonmethylated transcript isoforms tend to use distal APA sites. m6A-LAIC-seq yields a new perspective on transcriptome complexity and links APA usage to m6A modifications.
2016-06-24 | GSE66086 | GEO