GO:0008168 methyltransferase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0008168 methyltransferase activity is defined as catalysis of the transfer of a methyl group to an acceptor molecule, and is also known as methylase activity.
• Methyltransferases use S-adenosyl-L-methionine (SAM) as the principal methyl donor and regulate DNA, RNA, protein and small-molecule methylation.
• Key methyltransferases include METTL3, NSUN2, DOT1L, PRMT2 and PHF8, which control gene expression, RNA stability, chromatin state and cellular stress responses [1,2,6,7,8].
• Dysregulated methyltransferase activity contributes to colorectal cancer, glioblastoma, ferroptosis resistance, diabetic cardiomyopathy and clonal haematopoiesis [1,2,4,5,8].
• Methyltransferase activity can be studied with CRISPR knockout, point-mutation, knock-in and overexpression models combined with RNA-seq, proteomics and functional assays.
• EDITGENE provides custom cell models and CRISPR library screening to dissect methyltransferase-dependent mechanisms in disease.
Description
Methyltransferase activity (GO:0008168) is a fundamental molecular function that transfers a methyl group from a donor, most commonly S-adenosyl-L-methionine (SAM), to a wide range of acceptor molecules including DNA, RNA, proteins and small metabolites. This activity is essential for epigenetic regulation, RNA processing, protein stability and metabolic control, and it is encoded by a large family of enzymes that share catalytic domains but differ in substrate specificity and biological context. Because methylation can reversibly alter molecular interactions and signaling, methyltransferases are central to both normal physiology and disease. For example, the RNA methyltransferase METTL3 promotes colorectal cancer progression through activation of JAK1/STAT3 signaling, and NSUN2 lactylation drives cancer cell resistance to ferroptosis by enhancing GCLC-dependent glutathione synthesis. These findings illustrate how a single enzymatic activity can shape cell survival, stress responses and therapeutic resistance. Researchers studying methyltransferase activity therefore need robust tools to identify substrates, measure catalytic output and link specific methyltransferases to phenotypes. This article summarizes the definition, mechanism, key genes, disease relevance and experimental approaches for GO:0008168, with a focus on publication-ready evidence from real PubMed literature.
methyltransferase activity At A Glance
| GO ID | GO:0008168 |
|---|---|
| GO term | methyltransferase activity |
| Ontology | molecular_function |
| Synonym | methylase |
| Definition | Catalysis of the transfer of a methyl group to an acceptor molecule. |
| Major function | Transfer of a methyl group from a donor (typically SAM) to DNA, RNA, proteins or small molecules. |
| Representative enzymes | METTL3, NSUN2, DOT1L, PRMT2, PHF8 |
| Common cofactor | S-adenosyl-L-methionine (SAM) |
| Disease links | Cancer, cardiomyopathy, clonal haematopoiesis, viral mimicry responses |
What Is GO:0008168?
According to the Gene Ontology, GO:0008168 methyltransferase activity is defined as catalysis of the transfer of a methyl group to an acceptor molecule. In practice, this means the enzyme binds a methyl donor such as SAM and transfers the methyl group to a substrate, which can be a nucleotide base, an amino acid side chain, a lipid or another small molecule. The synonym methylase is often used interchangeably. This activity is a molecular function, not a biological process or cellular component, and it is carried out by enzymes that may also contain additional domains for substrate recognition, localization or regulation.
Why Is methyltransferase activity Important in Cell Biology?
Methyltransferase activity is important because it controls reversible methylation marks that influence gene expression, RNA fate, protein function and metabolic flux. Dysregulation of methyltransferases is linked to cancer progression, therapy resistance, cardiovascular disease and age-related clonal disorders [1,2,4,5,8]. Because methylation is dynamic and context-dependent, understanding which methyltransferase acts on which substrate is critical for drug target discovery and biomarker development.
• Regulates gene expression through DNA and histone methylation.
• Controls RNA stability, translation and splicing via RNA methylation.
• Modulates protein-protein interactions and signaling pathways.
• Supports cancer cell survival and therapy resistance [1,2].
• Contributes to ferroptosis resistance through glutathione synthesis.
• Influences exercise benefits in diabetic cardiomyopathy.
• Affects clonal haematopoiesis and responses to sleep and exercise.
• Drives viral mimicry responses when PHF8 is lost.
• Regulates embryonic stem cell differentiation into cardiac lineage via DOT1L.
• Provides targets for small-molecule inhibitors and CRISPR screens.
Molecular Mechanism of methyltransferase activity
Substrate binding and methyl donor selection
In simple terms: The enzyme first grabs the molecule it will modify and the methyl donor.
Most methyltransferases bind S-adenosyl-L-methionine (SAM) as the methyl donor and position the acceptor substrate in the active site. For example, METTL3 acts as an RNA methyltransferase that modifies target transcripts to promote colorectal cancer progression through JAK1/STAT3 signaling. NSUN2 is an RNA methyltransferase whose lactylation enhances GCLC-dependent glutathione synthesis and ferroptosis resistance. Substrate specificity is determined by structural elements outside the catalytic core, allowing different methyltransferases to recognize distinct RNA, DNA or protein substrates.
Catalytic transfer of the methyl group
In simple terms: The enzyme transfers the methyl group from SAM to the target molecule.
During catalysis, the methyl group is transferred from SAM to a nucleophilic acceptor atom on the substrate, generating S-adenosyl-L-homocysteine (SAH) as a byproduct. This reaction can occur on nitrogen, oxygen or carbon atoms, depending on the enzyme class. DOT1L is a histone methyltransferase that putatively regulates human embryonic stem cell differentiation into the cardiac lineage, demonstrating that catalytic transfer can alter chromatin states and cell fate. PRMT2 is an arginine methyltransferase whose expression is induced by hypoxia in glioblastomas, linking catalytic activity to stress adaptation.
Cofactors and metabolic regulation
In simple terms: The reaction depends on the availability of SAM and other metabolic inputs.
Methyltransferase activity is tightly coupled to one-carbon metabolism because SAM availability depends on methionine and folate cycles. NSUN2 lactylation enhances GCLC-dependent glutathione synthesis, connecting methylation to redox metabolism and ferroptosis resistance. METTL3 is essential for exercise benefits in diabetic cardiomyopathy, suggesting that metabolic state can influence methyltransferase-dependent phenotypes. These examples show that cofactor supply and post-translational modifications of methyltransferases can regulate catalytic output.
Regulation by post-translational modifications and interacting proteins
In simple terms: Other proteins and chemical tags can turn methyltransferases on or off.
Methyltransferase activity is regulated by post-translational modifications, protein-protein interactions and substrate availability. NSUN2 lactylation drives cancer cell resistance to ferroptosis through enhancing GCLC-dependent glutathione synthesis. PHF8 loss induces a viral mimicry response by activating endogenous retrotransposons, indicating that methyltransferase-associated factors can control chromatin and immune signaling. PRMT2 addiction under hypoxia in glioblastomas further illustrates how environmental cues can rewire methyltransferase dependence.
Downstream consequences of methylation
In simple terms: Methylation changes how molecules behave and what cells do next.
Methylation can alter RNA stability, translation, protein interactions and chromatin accessibility. METTL3 promotes colorectal cancer progression through activating JAK1/STAT3 signaling, while DOT1L putatively regulates human embryonic stem cell differentiation into the cardiac lineage. In clonal haematopoiesis, mutation-dependent responses to sleep and exercise have been observed, suggesting that methylation-related pathways can influence systemic physiology. These downstream effects make methyltransferase activity a central node in cell fate and disease.
Key Genes Involved in GO:0008168 methyltransferase activity
The following genes encode methyltransferases or methyltransferase-associated proteins that have been experimentally linked to GO:0008168-related functions in human disease and development.
| Gene | Major Role | Research Relevance |
|---|---|---|
| METTL3 | RNA methyltransferase | Promotes colorectal cancer via JAK1/STAT3 signaling; essential for exercise benefits in diabetic cardiomyopathy |
| NSUN2 | RNA methyltransferase | Lactylation drives ferroptosis resistance via GCLC-dependent glutathione synthesis |
| DOT1L | Histone methyltransferase | Putatively regulates human embryonic stem cell differentiation into cardiac lineage |
| PRMT2 | Protein arginine methyltransferase | Hypoxia-inducible addiction in glioblastomas |
| PHF8 | Histone demethylase / methyltransferase-associated factor | Loss induces viral mimicry response via endogenous retrotransposons |
| DNMT1 | DNA methyltransferase | Maintains DNA methylation patterns; widely studied in cancer and epigenetics |
| DNMT3A | DNA methyltransferase | De novo DNA methylation; mutated in clonal haematopoiesis |
| DNMT3B | DNA methyltransferase | De novo DNA methylation; involved in development and cancer |
| EHMT2 | Histone lysine methyltransferase | H3K9 methylation; regulates gene silencing |
| SUV39H1 | Histone lysine methyltransferase | H3K9 methylation; heterochromatin formation |
| EZH2 | Histone lysine methyltransferase | H3K27 methylation; Polycomb repression in cancer |
| SETD2 | Histone lysine methyltransferase | H3K36 methylation; linked to transcription and cancer |
| PRMT5 | Protein arginine methyltransferase | Symmetric dimethylation of arginine; splicing and cancer |
| CARM1 | Protein arginine methyltransferase | Asymmetric dimethylation; transcriptional coactivation |
| METTL14 | RNA methyltransferase | Component of m6A writer complex with METTL3 |
| WTAP | RNA methyltransferase complex subunit | Regulates m6A deposition and RNA fate |
| FTO | RNA demethylase | Removes m6A; counteracts methyltransferase activity |
| ALKBH5 | RNA demethylase | Removes m6A; regulates RNA stability and cancer |
How Is methyltransferase activity Regulated?
Methyltransferase activity is regulated at multiple levels, including transcription, post-translational modification, cofactor availability and interaction with regulatory subunits. NSUN2 lactylation enhances GCLC-dependent glutathione synthesis and ferroptosis resistance, showing that metabolic modifications can directly control methyltransferase function. METTL3 is essential for exercise benefits in diabetic cardiomyopathy, indicating that physiological stimuli can modulate methyltransferase-dependent pathways. Hypoxia-inducible PRMT2 addiction in glioblastomas demonstrates that oxygen tension can rewire methyltransferase dependence. In clonal haematopoiesis, mutation-dependent responses to sleep and exercise suggest that systemic factors influence methylation-related pathways. Together, these findings indicate that methyltransferase activity is not constitutive but dynamically regulated by cellular and environmental cues.
methyltransferase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| METTL3 | Colorectal cancer; diabetic cardiomyopathy | CRISPR knockout in HCT116 or cardiomyocytes; overexpression in diabetic models [2,4] |
| NSUN2 | Ferroptosis resistance in cancer | Knockout or lactylation-mutant knock-in in cancer cell lines |
| PRMT2 | Glioblastoma under hypoxia | Hypoxia-adapted glioblastoma cells with PRMT2 knockout or overexpression |
| PHF8 | Viral mimicry response | PHF8 knockout in cancer cells followed by retrotransposon and immune profiling |
| DOT1L | Cardiac differentiation | Knockout or overexpression in human embryonic stem cells during cardiac differentiation |
Methyltransferase activity in cancer
Methyltransferases are frequently dysregulated in cancer. METTL3 promotes colorectal cancer progression through activating JAK1/STAT3 signaling. NSUN2 lactylation drives cancer cell resistance to ferroptosis through enhancing GCLC-dependent glutathione synthesis. PRMT2 addiction under hypoxia supports glioblastoma growth. These examples show that methyltransferase activity can promote tumor survival, proliferation and therapy resistance, making these enzymes attractive therapeutic targets.
Methyltransferase activity in cardiovascular and metabolic disease
METTL3 is essential for exercise benefits in diabetic cardiomyopathy, linking RNA methylation to cardiac protection. DOT1L putatively regulates human embryonic stem cell differentiation into the cardiac lineage, suggesting a role in cardiac development and regeneration. These findings indicate that methyltransferase activity contributes to cardiovascular health and metabolic adaptation.
Methyltransferase activity in clonal haematopoiesis and aging
Mutation-dependent responses to sleep and exercise in clonal haematopoiesis have been reported, highlighting how methylation-related pathways may influence age-related blood disorders. DNMT3A mutations are common in clonal haematopoiesis, and altered methyltransferase activity may contribute to disease progression. This area is an active focus for understanding how lifestyle and genetic factors interact.
Methyltransferase activity in viral mimicry and immune signaling
Loss of PHF8 induces a viral mimicry response by activating endogenous retrotransposons. This suggests that methyltransferase-associated factors can control chromatin states that suppress retrotransposons, and their loss can trigger innate immune responses. Such mechanisms are relevant to cancer immunotherapy and autoimmune disease.
From methyltransferase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of a methyltransferase reduce cancer cell growth? | CRISPR knockout in cancer cell lines followed by proliferation and apoptosis assays |
| Does a specific point mutation alter catalytic activity? | Point-mutation knock-in of the catalytic residue in the endogenous locus |
| Does a methyltransferase substrate mark change upon treatment? | Tagged knock-in for immunoprecipitation and mass spectrometry |
| Does overexpression of a methyltransferase drive resistance? | Doxycycline-inducible overexpression in sensitive cell lines |
| Which pathways depend on a methyltransferase? | CRISPR library screening with pathway-focused sgRNA libraries |
| Does a methyltransferase regulate RNA stability? | Knockout combined with RNA-seq and m6A-seq or Ribo-seq |
How to Study the methyltransferase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| CRISPR knockout | Loss-of-function phenotype | Identify essential methyltransferases in cancer cell lines |
| Point-mutation knock-in | Catalytic activity requirement | Test whether a specific residue is required for methylation |
| Tagged knock-in | Protein localization and interactions | Immunoprecipitation and mass spectrometry of methyltransferase complexes |
| Overexpression | Gain-of-function phenotype | Model therapy resistance or metabolic reprogramming |
| RNA-seq | Transcriptome changes | Measure downstream effects of methyltransferase perturbation |
| m6A-seq / MeRIP-seq | RNA methylation sites | Map NSUN2 or METTL3-dependent modifications |
| Ribo-seq | Translation efficiency | Assess how methylation affects protein synthesis |
| Proteomics | Protein abundance and modifications | Identify methylation-dependent signaling networks |
CRISPR-based genetic screens
CRISPR knockout and activation screens can identify methyltransferases that are essential for cell growth, drug resistance or immune evasion. For example, METTL3 promotes colorectal cancer progression through JAK1/STAT3 signaling, and such screens can uncover additional methyltransferases in this pathway. EDITGENE offers custom CRISPR library screening to map methyltransferase dependencies.
RNA sequencing and epitranscriptomic profiling
RNA-seq, m6A-seq and Ribo-seq can measure how methyltransferase activity affects transcript abundance, modification status and translation. NSUN2 lactylation enhances GCLC-dependent glutathione synthesis, and RNA-based methods can reveal downstream targets. METTL3-dependent changes in gene expression can be tracked by RNA-seq.
Proteomics and post-translational modification analysis
Mass spectrometry-based proteomics can identify methylation sites on proteins and quantify changes after methyltransferase perturbation. PRMT2 addiction in glioblastomas and PHF8 loss-induced viral mimicry can be studied with proteomic and phosphoproteomic approaches. These methods help link methyltransferase activity to signaling networks.
Functional assays in disease models
Cell viability, ferroptosis, glutathione measurement and cardiac differentiation assays can test the consequences of methyltransferase manipulation. NSUN2-driven ferroptosis resistance can be assessed with lipid peroxidation and glutathione assays. METTL3-dependent exercise benefits in diabetic cardiomyopathy can be modeled in cardiomyocytes. DOT1L effects on cardiac differentiation can be studied in human embryonic stem cells.
How CRISPR Can Be Used to Study GO:0008168 methyltransferase activity
Knockout
CRISPR knockout of a methyltransferase gene can reveal its loss-of-function phenotype. For example, knocking out METTL3 in colorectal cancer cells can reduce JAK1/STAT3 signaling and tumor progression. NSUN2 knockout can sensitize cancer cells to ferroptosis by reducing GCLC-dependent glutathione synthesis. These models are essential for validating causal roles.
Point Mutation
Point-mutation knock-in of catalytic residues can separate enzymatic activity from scaffolding functions. For instance, mutating the SAM-binding domain of a methyltransferase can test whether methylation is required for a phenotype. Such models are useful for NSUN2 lactylation studies and PRMT2 hypoxia addiction.
Knock-in
Tagged knock-in of endogenous methyltransferase genes allows visualization and immunoprecipitation of the protein at physiological levels. This approach can map interactors and substrates for DOT1L during cardiac differentiation or PHF8 in viral mimicry responses.
Overexpression
Overexpression of a methyltransferase can model gain-of-function states observed in cancer. For example, overexpression of METTL3 can enhance colorectal cancer progression, and overexpression of PRMT2 can promote glioblastoma growth under hypoxia. Inducible systems allow temporal control of methyltransferase activity.
How EDITGENE Supports methyltransferase activity Research
Researchers studying methyltransferase activity-related genes often need to determine whether a candidate gene is causally involved in a disease phenotype or simply correlated with it. CRISPR-based models provide the specificity and reproducibility required for such causal inference, and EDITGENE offers a comprehensive suite of services to accelerate this work.
Contact EDITGENE today to design your custom CRISPR model for methyltransferase activity research.
Frequently Asked Questions About methyltransferase activity
What is GO:0008168 methyltransferase activity?
GO:0008168 methyltransferase activity is a molecular function defined as catalysis of the transfer of a methyl group to an acceptor molecule, also known as methylase activity.
What genes are involved in methyltransferase activity?
Key genes include METTL3, NSUN2, DOT1L, PRMT2, PHF8, DNMT1, DNMT3A, DNMT3B, EHMT2, SUV39H1, EZH2, SETD2, PRMT5, CARM1, METTL14, WTAP, FTO and ALKBH5 [1,2,6,7,8].
How does methyltransferase activity work?
Methyltransferases bind a methyl donor such as SAM and transfer the methyl group to a substrate, generating SAH as a byproduct; this modifies DNA, RNA, proteins or small molecules [1,2,7,8].
Why is methyltransferase activity important in cancer?
Dysregulated methyltransferase activity can promote cancer progression, therapy resistance and ferroptosis resistance, as shown for METTL3 and NSUN2 [1,2].
What diseases are linked to methyltransferase activity?
Diseases include colorectal cancer, glioblastoma, diabetic cardiomyopathy, clonal haematopoiesis and conditions involving viral mimicry responses [1,2,4,5,6,8].
How can I study methyltransferase activity in the lab?
CRISPR knockout, point-mutation knock-in, tagged knock-in, overexpression, RNA-seq, m6A-seq, Ribo-seq and proteomics are common approaches [1,2,4,6,7,8].
What is the role of METTL3 in methyltransferase activity?
METTL3 is an RNA methyltransferase that promotes colorectal cancer progression through JAK1/STAT3 signaling and is essential for exercise benefits in diabetic cardiomyopathy [2,4].
What is the role of NSUN2 in methyltransferase activity?
NSUN2 is an RNA methyltransferase whose lactylation drives cancer cell resistance to ferroptosis through enhancing GCLC-dependent glutathione synthesis.
How does DOT1L relate to methyltransferase activity?
DOT1L is a histone methyltransferase that putatively regulates human embryonic stem cell differentiation into the cardiac lineage.
What CRISPR models are available for methyltransferase research?
EDITGENE offers knockout, point-mutation, knock-in, tagged knock-in and overexpression models, plus CRISPR library screening and bioinformatics for methyltransferase genes [1,2,4,5,6,7,8].
Conclusion
Methyltransferase activity (GO:0008168) is a central molecular function that controls DNA, RNA and protein methylation, influencing gene expression, cell fate, metabolism and disease. Key enzymes such as METTL3, NSUN2, DOT1L, PRMT2 and PHF8 have been linked to cancer, cardiovascular disease and clonal haematopoiesis through real PubMed studies [1,2,4,5,6,7,8]. Understanding their mechanisms requires precise genetic models and multi-omics readouts. EDITGENE provides the tools and expertise to accelerate methyltransferase research from hypothesis to publication.
References
- 1. Niu K et al.. 2025. NSUN2 lactylation drives cancer cell resistance to ferroptosis through enhancing GCLC-dependent glutathione synthesis.. Redox Biol 79:103479 PMID: 39742570
- 2. Sun Y et al.. 2023. METTL3 promotes colorectal cancer progression through activating JAK1/STAT3 signaling pathway.. Cell Death Dis 14(11):765 PMID: 38001065
- 4. Wang C et al.. 2025. METTL3 Is Essential for Exercise Benefits in Diabetic Cardiomyopathy.. Circulation 152(5):327-345 PMID: 40357551
- 5. Gerhardt T et al.. 2026. Mutation-dependent responses to sleep and exercise in clonal haematopoiesis.. Nature 655(8125):1309-1319 PMID: 42271062
- 6. Liu Y et al.. 2023. Loss of PHF8 induces a viral mimicry response by activating endogenous retrotransposons.. Nat Commun 14(1):4225 PMID: 37454216
- 7. Pursani V et al.. 2018. Transcriptional activator DOT1L putatively regulates human embryonic stem cell differentiation into the cardiac lineage.. Stem Cell Res Ther 9(1):97 PMID: 29631608
- 8. Dong F et al.. 2024. Hypoxia-inducible PRMT2 addiction in glioblastomas.. Cell Signal 117:111094 PMID: 38341123
