Reactivity-dependent profiling of RNA 5-methylcytidine dioxygenases [II]
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE202814 | GEO | 2022/06/28
REPOSITORIES: GEO
Similar Datasets
Project description:Epitranscriptomic RNA modifications can regulate fundamental biological processes, but we lack approaches to map modification sites and probe writer enzymes. Here we present a chemoproteomic strategy to characterize RNA 5-methylcytidine (m5C) dioxygenase enzymes in their native context based upon metabolic labeling and activity-based crosslinking with 5-ethynylcytidine (5-EC), RNA-protein enrichment, and quantitative proteomics. We profile m5C dioxygenases in human cells including ALKBH1 and TET2 and use quantitative nucleoside LC-MS to show that ALKBH1 is the major hm5C and f5C-forming enzyme in RNA, including upon polyadenylated RNA. Further, we map ALKBH1 modification sites transcriptome-wide using 5-EC-based iCLIP analysis to show that ALKBH1 oxidizes m5C in a variety of tRNA anticodon stem loops (ASL), as well as on mRNA and lncRNA, and analyze its substrate specificity using in vitro enzymatic assays. Finally, we apply pyridine borane-mediated sequencing to identify f5C sites in tRNA ASLs. Our work provides powerful chemical approaches for studying RNA m5C dioxygenases and mapping oxidative m5C modifications and reveals the existence of novel epitranscriptomic pathways for regulating RNA function.
2022-07-16 | PXD029955 | Pride
Project description:Protein carbonylation has been consistently used as a marker of excessive oxidative stress and studied in the context of multiple human oxidative stress related diseases. The variety of carbonyl post-translational modifications (PTMs) and their low abundance on easily accessible diagnostic tissues (e.g., plasma) challenges their reproducible identification and quantitation. However, the use of carbonyl-specific biotinylated derivatization tags (e.g., aldehyde reactive probe, ARP) allows targeting carbonyl PTMs and enriching proteins and/or peptides carrying these modifications that facilitate their characterization. In this study, an oxidized human serum albumin protein model (OxHSA) and plasma proteins from a healthy individual were derivatized with ARP, digested with trypsin, and ARP-derivatized peptides (ARP-peptides) were enriched using biotin-avidin affinity chromatography prior to RPC-TWIMS-MS/MS analysis. The present workflow highlights previously overlooked analytical challenges, shows the use of ARP specific fragment ions to improve identification reliability of ARP-peptide identifications, and displays an extensive validation of the reproducible recovery and relative quantitation of ARP-peptides. HSA was identified as the most heavily modified protein by a variety of direct amino acid oxidation products and adducts from reactive carbonyl species (RCS). Most RCS modification sites were identified in six HSA modification hotspots (Lys10, Lys190, Lys199, Lys281, Lys432, and Lys525).
2021-03-02 | PXD023738 | Pride
Project description:We adapted the iCLIP method to map ALKBH1L modification sites in a transcriptome-wide manner by treating the cells with 5-EC.
2022-06-28 | GSE189261 | GEO
Project description:Cysteine is unique among all protein-coding amino acids owing to its intrinsically high nucleophilicity. The cysteinyl thiol group can be covalently modified by both a broad range of redox mechanisms and various electrophiles derived from exogenous or endogenous sources. Measuring proteomic cysteines response to redox perturbation or electrophiles is critical for understanding the underlying mechanisms involved. Activity-based protein profiling (ABPP) based on thiol-reactive probes has been the method of choice for such analyses. We therefore adapted this approach and developed a new chemoproteomic platform, termed as QTRP (Quantitative Thiol Reactivity Profiling), that relies on the ability of a commercially available thiol-reactive probe IPM to covalently label, enrich, and quantify the reactive cysteinome in cells and tissues. Here, we provide a detailed and updated workflow of QTRP that includes procedures for (i) labeling of the reactive cysteinome from cell or tissue samples (e.g. control vs treatment) with IPM, (ii) processing the protein samples into tryptic peptides and tagging the probe-modified peptides with isotopically labeled azido-biotin reagents containing a photo-cleavable linker via click chemistry reaction, (iii) capturing biotin-conjugated peptides with streptavidin beads, (iv) identifying and quantifying the photo-released peptides by mass spectrometry (MS)-based shotgun proteomics, (v) interpreting MS data by a streamlined informatic pipeline using a proteomics software, pFind 3, and an automatic post-processing algorithm. We also outline here how to use QTRP for measuring the changes on proteomic cysteines upon redox perturbation and for identifying targeted cysteine sites of thiol-reactive electrophiles. We anticipate that this protocol should find broad applications in both redox/chemical biology and drug discovery. The protocol for sample preparation takes 3 days, whereas MS measurements and data analyses require 75 min and <30 min, respectively, per sample.
2020-07-24 | PXD016048 | Pride
Project description:Epitranscriptomic RNA modifications can regulate fundamental biological processes, but we lack approaches to map modification sites and probe writer enzymes. Here we present a chemoproteomic strategy to characterize RNA 5-methylcytidine (m5C) dioxygenase enzymes in their native context based upon metabolic labeling and activity-based crosslinking with 5-ethynylcytidine (5-EC). We profile m5C dioxygenases in human cells including ALKBH1 and TET2 and show that ALKBH1 is the major hm5C- and f5C-forming enzyme in RNA. Further, we map ALKBH1 modification sites transcriptome-wide using 5-EC-iCLIP and ARP-based sequencing to identify ALKBH1-dependent m5C oxidation in a variety of tRNAs and mRNAs and analyze ALKBH1 substrate specificity in vitro. We also apply targeted pyridine borane-mediated sequencing to measure f5C sites on select tRNA. Finally, we show that f5C at the wobble position of tRNA-Leu-CAA plays a role in decoding Leu codons under stress. Our work provides powerful chemical approaches for studying RNA m5C dioxygenases and mapping oxidative m5C modifications and reveals the existence of novel epitranscriptomic pathways for regulating RNA function.
| S-EPMC9296451 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below.
2022-06-28 | GSE202815 | GEO
Project description:Cysteine is the most intrinsically nucleophilic residue in proteins and serves as a sentinel against increasing reactive oxygen species (ROS) via reversible thiol oxidation. Despite the importance of Cys oxidation in understanding biological stress response, it remains largely unknown and a major analytical challenge to determine which protein Cys-sites are the most reactive toward ROS. Herein, we describe initial coverage and sensitivity of a chemical proteomic method to quantify site-specific Cys reactivity using a maleimide-activated, thiol-specific probe (N-propargylmaleimide, NPM).
2020-10-20 | PXD015409 | Pride
Project description:To investigate selectivity of mRNA oxidation, total RNA and oxidized RNA isolated from Neuro 2a cells before and after H2O2 treatment were employed for microarray analysis. It was found that selective oxidation of mRNA already occurs under normal culture conditions but was increased by H2O2, especially in a subset of mRNAs related to certain functions. Moreover, mRNA oxidation level is also related to its abundance or stability (half-life time). This shows for the first time that mRNA oxidation is associated with RNA homeostasis including function, stability and abundance depending on cellular redox status in a genome-wide scale. Neuro 2a cells received hydrogen peroxide treatment or no treatment as a control. Samples were applied for RNA extraction and ARP labeling, which could bind with apurinic/apyrimidinic sites, and then a pull-down process to isolate oxidized RNA. Total RNA and oxidized RNA were used for subsequent transcriptomic profiling. 4 types of samples were analyzed: Basal-total: untreated N2a cells labeled with ARP, but not processed for the pull-down assay. Ox-total: hydrogen peroxide-treated N2a cells labeled with ARP, but not processed for the pull-down assay. Basal-ARP: untreated N2a cells labeled with ARP, and processed for the pull-down assay. ARP-derivatized RNA, which is also oxidized RNA, was concentrated and used for the microarray analysis. Ox-ARP: hydrogen peroxide-treated N2a cells labeled with ARP, and processed for the pull-down assay. ARP-derivatized RNA, which is also oxidized RNA, was concentrated and used for the microarray analysis.
2012-10-01 | E-GEOD-39641 | biostudies-arrayexpress
Project description:DNA N6-methyladenosine (6mA) in eukaryotic genomes has recently been observed in diverse species. 6mA has been reported to associate with multiple physiological processes including embryonic development and tumorigenesis, and ALKBH1 is a primary 6mA demethylase in mouse and human cells. To research the roles of 6mA and its putative regulators such as putative ALKBH1 in the homeostatic maintenance of human stem cells and their differentiated derivatives, We generated ALKBH1-deficient human embryonic stem cells (hESCs) via CRISPR/Cas9-mediated non-homologous end joining (NHEJ). We next differentiated ALKBH1+/+ and ALKBH1-/- hESCs into human mesenchymal stem cells (hMSCs) and vascular smooth muscle cells (hVSMCs). Early-onset growth arrest of ALKBH1-/- hMSCs was observed, and increased apoptosis and enhanced migration ability were observed in ALKBH1-/- hVSMCs. However, liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) analysis revealed no change in 6mA levels between ALKBH1+/+ and ALKBH1-/- hESCs, between ALKBH1+/+ and ALKBH1-/- hMSCs, and between ALKBH1+/+ and ALKBH1-/- hVSMCs, respectively. These data demonstrate that depletion of ALKBH1 exerts minimal impact on 6mA levels in hESCs and their differentiated derivatives and that ALKBH1 regulates the homeostasis of hMSCs and hVSMCs possibly in a DNA 6mA-independent manner.
2020-05-22 | GSE150936 | GEO
Project description:Astrocytes differentiate into a spectrum of neurotoxic and neuroprotective reactive subpopulations after CNS injury and in disease. In astrocyte conditional ADCY10 (sAC) knockout mice, reactive astrocytes exhibit a shift towards neurotoxic phenotypes implicating sAC as a critical regulator of neuroprotective astrocyte differentiation.
2023-12-11 | GSE237675 | GEO