Project description:N6-methyladenosine (m6A) is the most abundant chemical modification in mRNA, and plays important roles in human embryonic stem cell pluripotency, maintenance, and differentiation. However, the role of m6A and the precise mechanisms involved during the development of β-cells are unexplored. Here, we differentiated human embryonic stem cells (hESCs) into pancreatic β-like cells and performed RNA-Seq and m6A-seq at different stages of in vitro β-like cell differentiation.
Project description:Hypoxia as a crucial pathogenesis factor usually results in huge harmful effects on cardiac injury and dysfunction. In our previous study (PMID: 33294289), We observe a series of differential expressed genes between transcription and translation, which may be attributed to the hypoxia-specific binding affinity of Nuclear cap-binding subunit 3 (NCBP3) at 5’ un-translation region of target genes. But the underlying molecular mechanism of NCBP3 for gene translation modulation remains unclear. Here, we conducted RIP-seq of N6-Methyladenosine methylation in H9C2 cells with the conditions of normoxic, hypoxic and with additional NCBP3 knockdown.
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:Oxaliplatin as a first-line drug frequently causes the chemo-resistance on colorectal cancer (CRC). N6-methyladenosine (m6A) methylation has been largely acknowledged in multiple biological functions. However, the molecular mechanisms underlying the m6A methylation in modulating anticancer drug resistance in CRC are still obscure. In present study, RIP-seq was conducted to investigate the occupancy of N6-methyladenosine RNA binding protein 3 (YTHDF3) served as “readers” that can recognize m6A modification site in HCT116 cells with oxaliplatin resistance (HCT116R). Then, YTHDF3 was knockdown by siRNA in HCT116 cells with oxaliplatin resistance, and RIP-seq was further conducted to investigate m6A methylation of HCT116, HCT116R and HCT116R cells with YTHDF3 knockdown.
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:N6-methyladenosine (m6A) is the most abundant internal modification in the messenger RNA (mRNA) of all higher eukaryotes. This modification has been shown to be reversible in mammals; it is installed by a methyltransferase heterodimer complex of METTL3 and METTL14 bound with WTAP, and reversed by iron(II)- and α-ketoglutarate-dependent demethylases FTO and ALKBH5. This modification exhibits significant functional roles in various biological processes. The m6A modification as a RNA mark is recognized by reader proteins, such as YTH domain family proteins and HNRNPA2B1; m6A can also act as a structure switch to affect RNA-protein interactions for biological regulation. In Arabidopsis thaliana, the methyltransferase subunit MTA (the plant orthologue of human METTL3, encoded by At4g10760) was well characterized and FIP37 (the plant orthologue of human WTAP) was first identified as the interacting partner of MTA. Here we report the discovery and characterization of reversible m6A methylation mediated by AtALKBH10B (encoded by At4g02940) in A. thaliana, and noticeable roles of this RNA demethylase in affecting plant development and floral transition. Our findings reveal potential broad functions of reversible mRNA methylation in plants. m6A peaks were identified from wild type Columbia-0 and atalkbh10b-1 mutant in two biological replicates
Project description:Oxaliplatin as a first-line drug frequently causes the chemo-resistance on colorectal cancer (CRC). N6-methyladenosine (m6A) methylation has been largely acknowledged in multiple biological functions. However, the molecular mechanisms underlying the m6A methylation in modulating anticancer drug resistance in CRC are still obscure. In present study, RNA-seq was conducted to investigate the transcriptome of CRC tissues from three patients at different disease stages (CapeOx combined chemotherapy sensitivity and resistance).