Project description:To identify N6-methyladenosine RNA methylome in cyclophosphamide-treated neonatal rat cardiac myocytes (NRCMs), MeRIP-seq of NRCMs treated with cyclophosphamide (CYP) or solvent control (DMSO) were performed.
Project description:We show that N6-methyladenosine (m6A), the most abundant internal modification in mRNA/lncRNA with still poorly characterized function, alters RNA structure to facilitate the access of RBM for heterogeneous nuclear ribonucleoprotein C (hnRNP C). We term this mechanism m6A-switch. Through combining PAR-CLIP with Me-RIP, we identify 39,060 m6A-switches among hnRNP C binding sites transcriptome-wide. We show that m6A-methyltransferases METTL3 or METTL14 knockdown decreases hnRNP C binding at 16,582 m6A-switches. Taken together, 2,798 m6A-switches of high confidence are identified to mediate RNA-hnRNP C interactions and affect diverse biological processes including cell cycle regulation. These findings reveal the biological importance of m6A and provide insights into the sophisticated regulation of RNA-RBP interactions through m6A-induced RNA structural remodeling. Measure the m6A methylated hnRNP C binding sites transcriptome-wide by PARCLIP-MeRIP; measure the differential hnRNP C occupancies upon METTL3/METTL14 knockdown by PAR-CLIP; measure RNA abundance and splicing level changes upon HNRNPC, METTL3 and METTL14 knockdown
Project description:To investigate the function of N6-methyladenosine methylome (m6A) in adipose stem and progenitor cells isolated from facial infiltrating lipomatosis (FIL-ASPCs), we analyzed m6A enrichment level in FIL-ASPCs with or without FTO inhibitor (FTO-IN-1) treatment through methylated RNA immunoprecipitation (MeRIP) sequencing.
Project description:Although internal PolyA RNA modification N6-methyladenosine (m6A) plays essential roles in diverse biological processes, technology to detect precise m6A sites at transcriptome-wide scale is lacking. Here, we discovered that m6A interferes A (Adenine) – U (Uracil) or A-T (Thymidine) pairing. Based on differential hybridization between methylated vs. unmethylated RNAs to a DNA probe, we developed tiling microarray to pinpoint m6A sites in mouse transcriptome. We validated some of the identified sites and provided evidence to suggest that one functional mechanism of m6A is to block small RNA targeting to methylated mRNA. We designed a custom tiling array with to examine the precise location of m6A within meRIP-seq peaks from mouse embryonic stem cells determined in our previous publication (Wang et al., 2014). Each custom two-channel Agilent tiling array harbors 947,952 probes. Each probe is 25 nucleotides (nt), and any two adjacent probes in the genomic coordinate overlap each other by 19 nt. The Cy5 or red channel corresponds to Mettl14 knockout (M14) or DZA mutant mESC cell line, and Cy3 or green channel is associated with wild type cell line treated with scramble hairpin (SCR). Thus, in principle a higher Cy5/Cy3 signal for each probe reflects an increased hybridization to the oligonucleotide due to de-methylation of a particular RNA molecule in M14 or DZA condition relative to the SCR control. Moreover, we employed additional arrays with both channels dedicated for M14 as an external control for technical difference between the Cy5 and Cy3 dye (details below). For each comparison, we have three biological replicates, and therefore there are 9 tiling arrays in total (i.e., 3 arrays for M14 vs SCR, 3 arrays for DZA vs SCR, and 3 arrays for M14 vs M14).
Project description:Epigenetic modifications play important roles in genome evolution and innovation. However, most analyses have focused on the evolutionary role of DNA modifications, and little is understood about the influence of posttranscriptional RNA modifications on genome evolution. To explore the evolutionary significance of RNA modifications, we generated transcriptome-wide profiles of N6-methyladenosine (m6A), the most prevalent internal modification of mRNA, for 13 representative plant species spanning over half a billion years of evolution. These data reveal the evolutionary conservation and divergence of m6A methylomes in plants, uncover the preference of m6A modifications on ancient orthologous genes, and demonstrate less m6A divergence between orthologous gene pairs with earlier evolutionary origins. Further investigation revealed that the evolutionary divergence of m6A modifications is related to sequence variation between homologs from whole-genome duplication and gene family expansion from local-genome duplication. Unexpectedly, a significant negative correlation was found between the retention ratio of m6A modifications and the number of family members. Moreover, the divergence of m6A modifications is accompanied by variation in the expression level and translation efficiency of duplicated genes from whole- and local-genome duplication. Our work reveals new insights into evolutionary patterns of m6A methylomes in plant species and their implications, and provides a resource of plant m6A profiles for further studies of m6A regulation and function in an evolutionary context.
Project description:Purpose: To comprehensively profile the landscape of the mRNA N6-methyladenosine (m6A) modification in human colorectal cancer (CRC). Methylated RNA immunoprecipitation sequencing (MeRIP-seq) was explored to compare the difference in mRNA N6-methyladenosine (m6A) methylation between CRC tissues and adjacent normal control (NC) tissue. RNA-sequencing (RNA-seq) was performed to transcribe differentially expressed mRNAs. Conjoint analysis of MeRIP-seq and RNA-seq data was conducted to predict RNA-binding proteins (RBPs). Results: MeRIP-seq identified 1110 differentially m6A methylated sites (DMMSs) and 980 differentially m6A methylated genes (DMMGs) in CRC, with 50.13% of all modified genes showing unique m6A-modified peaks in CRC. RNA-seq showed 915 upregulated genes and 1463 downregulated genes in CRC. QRT-PCR verified the RNA-seq results by detecting the expression of some mRNAs. Conjoint analysis of MeRIP-seq and RNA-seq identified 400 differentially m6A methylated and expressed genes (DEGs), and pathway analysis detected that DMMGs and DEGs were closely related to cancer. After analyzing these DMMGs and DEGs through the GEPIA database, we found that the expression of B3GNT6, DKC1, SRPK1 and RIMKLB were associated with prognosis, and the expression of B3GNT6 and RIMKLB were associated with clinical stage. 17 RBPs were identified based on the DMMGs and DEGs, among which FXR1, FXR2, FMR1, IGF2BP2, IGF2BP3 and SRSF1 were obviously highly expressed in CRC, and FMR1, IGF2BP2 and IGF2BP3 were closely related to methylation, and might be involved in the development of CRC. Conclusions: This study comprehensively profiled m6A modification of mRNAs in CRC, which revealed possible mechanisms of m6A-mediated gene expression regulation.
Project description:N6-methyladenosine (m6A) is the most abundant internal messenger (mRNA) modification in mammalian mRNA. This modification is reversible and non-stoichiometric, which potentially adds an additional layer of variety and dynamic control of mRNA metabolism. The m6A-modified mRNA can be selectively recognized by the YTH family “reader” proteins. The preferential binding of m6A-containing mRNA by YTHDF2 is known to reduce the stability of the target transcripts; however, the exact effects of m6A on translation has yet to be elucidated. Here we show that another m6A reader protein, YTHDF1, promotes ribosome loading of its target transcripts. YTHDF1 forms a complex with translation initiation factors to elevate the translation efficiency of its bound mRNA. In a unified mechanism of translation control through m6A, the YTHDF2-mediated decay controls the lifetime of target transcripts; whereas, the YTHDF1-based translation promotion increases the translation efficiency to ensure effective protein production from relatively short-lived transcripts that are marked by m6A. PAR-CLIP and RIP was used to identify YTHDF1 binding sites followed by ribosome profling and RNA seq to assess the consequences of YTHDF1 siRNA knock-down
Project description:To identify the m6A methylome in the aorta of patients with acute aortic dissection. MeRIP-seq and RNA-seq experiments of aortic media tissue samples obtained from AD patients and controls were conducted. Compared with control group, the upmethylated coding genes of AD were primarily enriched in the processes associated with extracellular fibril organization, while the genes with downmethylation were enriched in the processes associated with cell death regulation. Furthermore, many differentially methylated m6A sites (DMMSs) coding proteins were mainly annotated during the extracellular matrix and inflammatory responses.