Search Results (11)

YTH domain-containing proteins act as the primary readers of N⁶-methyladenosine (m⁶A), playing an important role in plant development and stress responses. However, little is known about the YTH proteins in medicinal plants. Genome-wide identification of the YTH gene family in the medicinal model plant, Salvia miltiorrhiza Bunge, identified a total of nineteen SmYTH genes from five chromosomes, with SmYTH8–SmYTH19 clustered on chromosome 8. Phylogenetic analysis showed that SmYTH proteins belong to the YTHDF category. No YTHDC members were identified. Conserved domain identification, amino acid sequence alignment, and phase separation prediction revealed that SmYTH1–SmYTH4 exhibited the characteristic m⁶A reader protein feature, containing conserved aromatic cages (WWW) capable of binding m⁶A residues. SmYTH5–SmYTH19 proteins contain a unique conserved F-box protein interaction domain that has not been reported previously. qRT-PCR analysis revealed tissue-specific patterns, with SmYTH1–SmYTH4 genes highly expressed in roots and leaves, whereas SmYTH8–SmYTH19 were mainly expressed in leaves. The results were consistent with RNA-seq data. The expression of various SmYTHs and the content of phenolic acid active ingredients were significantly altered under MeJA and SA treatments. The results provide useful information for further studies on the biological functions of m⁶A and YTH proteins in S. miltiorrhiza. Full article

Background/Objectives: PARP inhibitors (PARPi) are pivotal to treating homologous recombination repair-deficient (HRD) cancers, particularly BRCA1/2-mutated ovarian and breast cancers. However, most ovarian and breast cancers harbor wild-type (WT) BRCA1/2, limiting PARPi eligibility. This study aims to identify an approved drug that could induce a BRCAness phenotype, thereby sensitizing WT BRCA cancers to PARPi. Methods: Ovarian and breast cancer cell lines with WT BRCA1/2 were treated with ivosidenib. HR repair efficiency was assessed via RAD51 foci formation and reporter assays. Synthetic lethality with PARPi was evaluated using viability and colony formation assays. Mechanistic studies included RNA-binding protein pulldown, co-immunoprecipitation, and functional analyses of DNA repair pathways. YTHDC2′s role in HR was investigated through siRNA knockdown and rescue experiments. Results: Ivosidenib significantly reduced HR repair efficiency and sensitized cells to PARPi, inducing synthetic lethality. Mechanistically, ivosidenib directly bound YTHDC2, an m6A reader critical for HR. This interaction disrupted YTHDC2′s ability to promote DNA double-strand break repair via HR, evidenced by impaired recruitment of repair proteins (e.g., BRCA1, RAD51) and accumulation of DNA damage (γH2AX foci). YTHDC2 knockdown phenocopied ivosidenib effects, while overexpression rescued HR defects. Conclusions: Ivosidenib induces BRCAness in WT BRCA ovarian and breast cancers by targeting YTHDC2, thereby suppressing HR repair and enhancing PARPi sensitivity. This uncovers a novel, metabolism-independent mechanism of ivosidenib, repositioning it as a therapeutic agent for HRD tumors. These findings propose a strategy to expand PARPi eligibility to WT BRCA cancers, addressing a critical unmet need in oncology. Full article

N6-methyladenosine (m6A) is the most common and abundant internal co-transcriptional modification in eukaryotic RNAs. This modification is catalyzed by m6A methyltransferases, known as “writers”, including METTL3/14 and WTAP, and removed by demethylases, or “erasers”, such as FTO and ALKBH5. It is recognized by m6A-binding proteins, or “readers”, such as YTHDF1/2/3, YTHDC1/2, IGF2BP1/2/3, and HNRNPA2B1. Cardiovascular diseases (CVDs) are the leading cause of morbidity and mortality worldwide. Recent studies indicate that m6A RNA modification plays a critical role in both the physiological and pathological processes involved in the initiation and progression of CVDs. In this review, we will explore how m6A RNA methylation impacts both the normal and disease states of the cardiovascular system. Our focus will be on recent advancements in understanding the biological functions, molecular mechanisms, and regulatory factors of m6A RNA methylation, along with its downstream target genes in various CVDs, such as atherosclerosis, ischemic diseases, metabolic disorders, and heart failure. We propose that the m6A RNA methylation pathway holds promise as a potential therapeutic target in cardiovascular disease. Full article

YTHDC1 (YTH domain containing 1), a crucial reader protein of N6-methyladenosine (m6A) mRNA, plays a critical role in various cellular functions and is considered a promising target for therapeutic intervention in acute myeloid leukemia and other cancers. In this study, we identified orthosteric small-molecule ligands for YTHDC1. Using a molecular docking approach, we screened the eMolecules database and recognized 15 top-ranked ligands. Subsequently, molecular dynamics simulations and MM/PBSA analysis were used to assess the stability and binding free energy of these potential hit compounds in complex with YTHDC1. Notably, five compounds with IDs of ZINC82121447, ZINC02170552, ZINC65274016, ZINC10763862, and ZINC02412146 exhibited high binding affinities and favorable binding free energies. The results also showed that these compounds formed strong hydrogen bonds with residues SER378, ASN363, and ASN367 and interacted with the aromatic cage of the YTHDC1 reader protein through TRP377, TRP428, and hydrophobic residue LEU439. To assess their viability as lead compounds, we conducted absorption, distribution, metabolism, excretion, and toxicity (ADMET) studies to reveal promising features for these identified small molecules, shedding light on their pharmacokinetic and safety profiles. Full article

Respiratory syncytial virus (RSV) is the most prevalent cause of acute lower respiratory infection in young children. Currently, the first RSV vaccines are approved by the FDA. Recently, N6-methyladenosine (m⁶A) RNA methylation has been implicated in the regulation of the viral life cycle and replication of many viruses, including RSV. m⁶A methylation of RSV RNA has been demonstrated to promote replication and prevent anti-viral immune responses by the host. Whether m⁶A is also involved in viral entry and whether m⁶A can also affect RSV infection via different mechanisms than methylation of viral RNA is poorly understood. Here, we identify m⁶A reader YTH domain-containing protein 1 (YTHDC1) as a novel negative regulator of RSV infection. We demonstrate that YTHDC1 abrogates RSV infection by reducing the expression of RSV entry receptor CX3C motif chemokine receptor 1 (CX3CR1) on the cell surface of lung epithelial cells. Altogether, these data reveal a novel role for m⁶A methylation and YTHDC1 in the viral entry of RSV. These findings may contribute to the development of novel treatment options to control RSV infection. Full article

Background: The pivotal roles of long noncoding RNAs (lncRNAs) in the realm of cancer biology, inclusive of bladder cancer (BCa), have been substantiated through various studies. Remarkably, RNA methylation, especially m6A modification, has demonstrated its influence on both coding and noncoding RNAs. Nonetheless, the explicit impact of RNA methylation on lncRNAs and its subsequent contribution to the progression of BCa remains to be elucidated. Methods: In the present investigation, we scrutinized the expression and m6A methylation status of LINC01106, employing quantitative real-time PCR (qRT–PCR) and methylated RNA immunoprecipitation (MeRIP)-qPCR. To decipher the regulatory mechanism underpinning LINC01106, we utilized RNA immunoprecipitation (RIP)-qPCR, methylated RNA immunoprecipitation (MeRIP) assays, and bioinformatic analysis. Furthermore, the CRISPR/dCas13b-METTL3-METTL14 system was implemented to probe the function of LINC01106. Results: The findings of our study indicated that LINC01106 is under expressed and exhibits diminished m6A methylation levels in BCa tissues when compared those of normal controls. A diminished expression of LINC01106 was associated with a less favorable prognosis in BCa patients. Intriguingly, CRISPR-mediated hypermethylation of LINC01106, facilitated by dCas13b-M3-M14, abolished the malignant phenotype of the BCa cells, an effect that could be inverted by Disabled-1 (DAB1) knockdown. From a mechanistic standpoint, we identified an m6A modification site on LINC01106 and highlighted YTHDC1 as a potential reader protein implicated in this process. Additionally, a positive correlation between DAB1 and LINC01106 expression was observed, with miR-3148 potentially acting as a mediator in this relationship. Conclusions: In summary, our research unveils a suppressive regulatory role of the LINC01106/miR-3148/DAB1 axis in the progression of BCa and underscores the YTHDC1-mediated m6A modification mechanism in regards to LINC01106. These revelations propose a new therapeutic target for the management of BCa. Full article

The development of mammalian skeletal muscle is a highly complex process involving multiple molecular interactions. As a prevalent RNA modification, N6-methyladenosine (m⁶A) regulates the expression of target genes to affect mammalian development. Nevertheless, it remains unclear how m⁶A participates in the development of goat muscle. In this study, methyltransferase 3 (METTL3) was significantly enriched in goat longissimus dorsi (LD) tissue. In addition, the global m⁶A modification level and differentiation of skeletal muscle satellite cells (MuSCs) were regulated by METTL3. By performing mRNA-seq analysis, 8050 candidate genes exhibited significant changes in expression level after the knockdown of METTL3 in MuSCs. Additionally, methylated RNA immunoprecipitation sequencing (MeRIP-seq) illustrated that myocyte enhancer factor 2c (MEF2C) mRNA contained m⁶A modification. Further experiments demonstrated that METTL3 enhanced the differentiation of MuSCs by upregulating m⁶A levels and expression of MEF2C. Moreover, the m⁶A reader YTH N6-methyladenosine RNA binding protein C1 (YTHDC1) was bound and stabilized to MEF2C mRNA. The present study reveals that METTL3 enhances myogenic differentiation in MuSCs by regulating MEF2C and provides evidence of a post-transcriptional mechanism in the development of goat skeletal muscle. Full article

YTH domain-containing genes are important readers of N⁶-methyladenosine (m⁶A) modifications with ability to directly affect the fates of distinct RNAs in organisms. Despite their importance, little is known about YTH domain-containing genes in teleosts until now. In the present study, a total of 10 YTH domain-containing genes have been systematically identified and functionally characterized in rainbow trout (Oncorhynchus mykiss). According to the phylogenetic tree, gene structure and syntenic analysis, these YTH domain-containing genes could be classified into three evolutionary subclades, including YTHDF, YTHDC1 and YTHDC2. Of them, the copy number of OmDF1, OmDF2, OmDF3, and OmDC1 were duplicated or even triplicated in rainbow trout due to the salmonid-specific whole-genome duplication event. The three-dimensional protein structure analysis revealed that there were similar structures and the same amino acid residues that were associated with cage formation between humans and rainbow trout, implying their similar manners in binding to m⁶A modification. Additionally, the results of qPCR experiment indicated that the expression patterns of a few YTH domain-containing genes, especially OmDF1b, OmDF3a and OmDF3b, were significantly different in liver tissue of rainbow trout under four different temperatures (7 °C, 11 °C, 15 °C, and 19 °C). The expression levels of OmDF1a, OmDF1b and OmDC1a were obviously repressed in spleen tissue of rainbow trout at 24 h after Yersinia ruckeri infection, while increased expression was detected in OmDF3b. This study provides a systemic overview of YTH domain-containing genes in rainbow trout and reveals their biological roles in responses to temperature stress and bacterial infection. Full article

There is growing scientific evidence for the crucial role of post-transcriptional RNA modifications in carcinogenesis, progression, metastasis, and drug resistance across various cancer entities. N6-methyladenosine (m6A) is the most abundant type of RNA modification. m6A is coordinated by a dynamic interplay of ‘writers’ (METTL3, METTL4, METTL14, WTAP, KIAA1429), ‘erasers’ (FTO, ALKBH5), and ‘readers’ (HNRNPA2B1, HNRNPC, YTHDC1, YTHDC1, YTHDF1-3). In this study, we comprehensively examined protein and mRNA expression levels of m6A writers, readers, and erasers in two cervical cancer (CC) cohorts (UHB CC cohort, N = 118; TCGA CC cohort, N = 307) with regard to clinical outcomes. In the UHB CC cohort, high protein expression levels of METTL14 (p = 0.016), WTAP (p = 0.007), KIAA1439 (p < 0.001), ALKBH5 (p < 0.001), HNRNPC (p = 0.012), YTHDC1 (p < 0.001), and YTHDF3 (p = 0.004) were significantly associated with a shorter overall survival (OS). In the TCGA CC cohort, mRNA expression levels of METTL14 (p = 0.012), WTAP (p = 0.041), KIAA1429 (p = 0.016), and YTHDC1 (p = 0.026) showed prognostic values. However, after correction for multiple testing, statistical significance remained only for m6A protein expression levels (q < 0.1). Our study points towards dysregulated m6A modification in CC. Hence, m6A might serve as a promising prognostic biomarker and therapeutical target in CC. Full article

N6-methyladenosine (m⁶A) is a well-known RNA modification and has various functions with its binding proteins. Nuclear m⁶A reader protein YTHDC1 plays a significant role in RNA metabolism including some non-coding RNA such as LINE or circRNA. It is also known to regulate mRNA splicing through recruiting SRSF3 to the targeted mRNAs, which then mediates export of YTHDC1-bound RNA to the cytoplasm. Additionally, it has been indicated that SRSF3 binding to YHTDC1 may be mediated by its dephosphorylated status. However, their binding mechanism, including the positions of dephosphorylated residues of SRSF3, has not been sufficiently investigated. Thus, we explored the mechanism of interaction between SRSF3 and YTHDC1 in human cells. We used co-immunoprecipitation to examine the binding of YTHDC1/SRSF3 through their N- and C-terminal amino-acid residues. Furthermore, dephosphorylation-mimic serine to alanine mutants of SRSF3 indicated the position of phosphorylated residues. Cumulatively, our results demonstrate that YTHDC1 binding to SRSF3 is regulated by not only hypo-phosphorylated residues of arginine/serine-rich (RS) domain of SRSF3 but also other parts of SRSF3 via YTHDC1 N- or C-terminal residues. Our results contribute to the understanding of the complex mechanism of binding between SR protein SRSF3 and the m⁶A reader YTHDC1 to regulate the expression of mRNA and non-coding RNAs. Full article

N6-methyladenosine (m⁶A), the most abundant modification in messenger RNAs (mRNAs), is deposited by methyltransferases (“writers”) Mettl3 and Mettl14 and erased by demethylases (“erasers”) Fto and Alkbh5. m⁶A can be recognized by m⁶A-binding proteins (“readers”), such as Yth domain family proteins (Ythdfs) and Yth domain-containing protein 1 (Ythdc1). Previous studies have indicated that m⁶A plays an essential function in various fundamental biological processes, including neurogenesis and neuronal development. Dysregulated m⁶A modification contributes to neurological disorders, including neurodegenerative diseases. In this review, we summarize the current knowledge about the roles of m⁶A machinery, including writers, erasers, and readers, in regulating gene expression and the function of m⁶A in neurodevelopment and neurodegeneration. We also discuss the perspectives for studying m⁶A methylation. Full article