GO:0008170 N-methyltransferase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0008170 N-methyltransferase activity describes the catalysis of methyl group transfer to the nitrogen atom of an acceptor molecule, a fundamental post-translational and epigenetic modification.
• Key enzyme families include calmodulin-lysine N-methyltransferase (CaM KMT), SMYD2, SETDB1, NNMT, and MLL4, each targeting distinct nitrogen-containing substrates such as lysine residues, histones, or nicotinamide.
• N-methyltransferase activity regulates diverse biological processes including inflammation, hypoxia-induced pulmonary hypertension, embryonic stem cell differentiation, adult tissue regeneration, antitumor immunity, and skeletal muscle metabolism.
• Dysregulated N-methyltransferase activity is implicated in cancer progression, pulmonary hypertension, and metabolic disorders, making these enzymes attractive therapeutic targets.
• CRISPR-based knockout, point mutation, knock-in, and overexpression models are essential for dissecting the causal roles of N-methyltransferase enzymes in health and disease.
• Studying N-methyltransferase activity requires integrated methods such as methyltransferase assays, RNA-seq, proteomics, and phenotypic screening to link molecular function to cellular outcomes.
Description
N-methyltransferase activity (GO:0008170) is a molecular function defined as the catalysis of methyl group transfer to the nitrogen atom of an acceptor molecule. This activity is central to a wide array of biological processes, including epigenetic regulation, protein post-translational modification, and small-molecule metabolism. Enzymes with this activity often use S-adenosylmethionine (SAM) as a methyl donor, although the specific acceptor can vary from lysine residues on histones and non-histone proteins to small molecules like nicotinamide. The importance of N-methyltransferase activity is underscored by its roles in development, immunity, and disease. For instance, calmodulin-lysine N-methyltransferase suppresses caspase-11 non-canonical inflammasome activation, thereby modulating anti-inflammatory responses. SMYD2-mediated methylation of PPARγ contributes to hypoxia-induced pulmonary hypertension by activating mitophagy. SETDB1, a histone H3 lysine 9 methyltransferase, suppresses antitumor immunity, highlighting its role in immune evasion. Nicotinamide N-methyltransferase (NNMT) remodels cell metabolism and aggravates proinflammatory responses through the STAT3/IL1β/PGE2 pathway. These examples illustrate how a single enzymatic activity can influence diverse physiological and pathological states. For researchers, understanding N-methyltransferase activity is crucial for uncovering mechanisms of gene regulation, developing therapeutic strategies, and designing experiments that precisely manipulate these enzymes. The integration of CRISPR-based genome editing with biochemical and genomic assays offers a powerful approach to study this activity in relevant cellular contexts.
N-methyltransferase activity At A Glance
| GO ID | GO:0008170 |
|---|---|
| GO term | N-methyltransferase activity |
| Ontology | molecular_function |
| Synonym | none |
| Major function | Catalysis of methyl group transfer to a nitrogen atom of an acceptor molecule |
| EC number | 2.1.1.- |
| Common methyl donor | S-adenosylmethionine (SAM) |
| Representative enzymes | CaM KMT, SMYD2, SETDB1, NNMT, MLL4 |
| Subcellular location | Varies; often nuclear or cytoplasmic |
What Is GO:0008170?
N-methyltransferase activity (GO:0008170) is the catalysis of the transfer of a methyl group to the nitrogen atom of an acceptor molecule. This definition, from the Gene Ontology, encompasses enzymes that modify nitrogen-containing substrates, including proteins, nucleic acids, and small molecules. The activity is essential for various biological processes, such as epigenetic regulation, detoxification, and signal transduction.
Why Is N-methyltransferase activity Important in Cell Biology?
N-methyltransferase activity is fundamental to numerous biological processes, from epigenetic regulation to metabolic control. Its dysregulation is linked to cancer, inflammatory diseases, and metabolic disorders, making it a critical area of research for understanding disease mechanisms and developing targeted therapies.
• Regulates gene expression through histone methylation, influencing cell differentiation and development.
• Modulates immune responses, including inflammasome activation and antitumor immunity.
• Contributes to metabolic reprogramming in cancer and inflammation.
• Plays a role in hypoxia-induced pulmonary hypertension via PPARγ methylation.
• Impacts adult tissue regeneration by suppressing endogenous retroviruses.
• Serves as a therapeutic target for cancer, pulmonary hypertension, and inflammatory diseases.
• Essential for skeletal muscle metabolic efficiency through MLL4-mediated enhancer regulation.
• Provides a mechanistic link between environmental cues and epigenetic modifications.
• Enables precise dissection of gene function using CRISPR-based models.
• Facilitates the development of small-molecule inhibitors for clinical applications.
What Happens During N-methyltransferase activity?
Substrate Recognition and Binding
In simple terms: The enzyme grabs its target molecule and gets ready to add a methyl group.
N-methyltransferases recognize specific nitrogen-containing substrates, such as lysine residues on histone tails or small molecules like nicotinamide. For example, calmodulin-lysine N-methyltransferase specifically methylates calmodulin at lysine residues, a modification that modulates its function in inflammatory signaling. SMYD2 methylates PPARγ, a nuclear receptor involved in metabolic regulation, thereby influencing mitophagy under hypoxia. The binding specificity is determined by the enzyme's active site architecture and accessory domains that interact with the substrate.
Methyl Group Transfer
In simple terms: The enzyme transfers a methyl group from SAM to the nitrogen atom of the target.
Using S-adenosylmethionine (SAM) as the methyl donor, the enzyme catalyzes the transfer of a methyl group to the acceptor nitrogen. This reaction often results in mono-, di-, or tri-methylation, depending on the enzyme and substrate. For instance, SETDB1 catalyzes the methylation of histone H3 at lysine 9 (H3K9me), a mark associated with transcriptional repression and immune suppression. NNMT transfers a methyl group to nicotinamide, producing N1-methylnicotinamide, which affects cellular metabolism and proinflammatory responses.
Post-Transfer Consequences
In simple terms: After methylation, the target molecule changes its behavior, affecting cellular processes.
Methylation alters the chemical properties of the substrate, often creating docking sites for reader proteins or changing enzymatic activity. For example, H3K4me1, deposited by MLL4, facilitates promoter-enhancer interactions and gene activation during embryonic stem cell differentiation. In skeletal muscle, MLL4-mediated enhancer regulation controls metabolic efficiency by limiting AMPK-mediated fuel catabolism. These downstream effects link N-methyltransferase activity to diverse physiological outcomes.
Regulation of Enzyme Activity
In simple terms: The enzyme's activity is turned on or off by various signals.
N-methyltransferase activity is regulated at multiple levels, including expression, post-translational modifications, and interaction with regulatory partners. For instance, PRDX6 prevents NNMT ubiquitination and degradation, thereby stabilizing NNMT and promoting ovarian cancer progression. The SETDB1-TRIM28 complex is critical for SETDB1 function in suppressing antitumor immunity. Such regulatory mechanisms ensure that methylation occurs in a context-dependent manner.
Key Genes Involved in GO:0008170 N-methyltransferase activity
The following genes encode enzymes with N-methyltransferase activity or are directly involved in its regulation, as supported by recent literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| CaM KMT | Calmodulin-lysine N-methyltransferase; methylates calmodulin | Suppresses caspase-11 non-canonical inflammasome; anti-inflammatory |
| SMYD2 | Methylates PPARγ and other substrates | Facilitates hypoxia-induced pulmonary hypertension via mitophagy |
| SETDB1 | Histone H3K9 methyltransferase | Suppresses antitumor immunity; component of SETDB1-TRIM28 complex |
| NNMT | Nicotinamide N-methyltransferase | Remodels cell metabolism; aggravates proinflammatory responses |
| MLL4 | Histone H3K4 methyltransferase | Controls skeletal muscle metabolic efficiency; enhancer regulation |
| PRDX6 | Prevents NNMT ubiquitination and degradation | Promotes ovarian cancer progression |
| TRIM28 | Partners with SETDB1 | Suppresses antitumor immunity |
| PPARγ | Substrate of SMYD2 | Mediates hypoxia-induced pulmonary hypertension |
| STAT3 | Signaling molecule activated by NNMT | Promotes proinflammatory responses |
| IL1β | Cytokine induced by NNMT pathway | Aggravates inflammation |
| PGE2 | Prostaglandin induced by NNMT pathway | Promotes inflammation |
| AMPK | Energy sensor limited by MLL4 | Regulates fuel catabolism in skeletal muscle |
| Caspase-11 | Inflammatory caspase suppressed by CaM KMT | Non-canonical inflammasome |
| H3K4me1 | Epigenetic mark deposited by MLL4 | Facilitates promoter-enhancer interactions |
| H3K9me | Epigenetic mark deposited by SETDB1 | Transcriptional repression |
| Endogenous retrovirus | Suppressed by stem cell activity | Governs adult tissue regeneration |
How Is N-methyltransferase activity Regulated?
N-methyltransferase activity is regulated at multiple levels. Enzyme abundance can be controlled by ubiquitination and degradation, as shown for NNMT, which is protected from ubiquitination by PRDX6. Complex formation with partner proteins, such as the SETDB1-TRIM28 complex, is essential for catalytic activity and targeting. Post-translational modifications of the enzymes themselves, as well as availability of substrates and methyl donor SAM, further modulate activity. In skeletal muscle, MLL4-mediated enhancer regulation is linked to AMPK signaling, indicating cross-talk between methylation and metabolic pathways.
N-methyltransferase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| NNMT | Ovarian cancer progression; inflammation | KO and overexpression in ovarian cancer cell lines |
| SMYD2 | Hypoxia-induced pulmonary hypertension | Point mutation of PPARγ methylation site; KO in pulmonary cells |
| SETDB1 | Antitumor immunity; cancer | KO in tumor cells; syngeneic mouse models |
| CaM KMT | Inflammation; inflammasome activation | KO in macrophages; inflammasome assays |
| MLL4 | Skeletal muscle metabolism | KO in muscle cells; metabolic flux assays |
N-methyltransferase activity in Cancer
Dysregulated N-methyltransferase activity contributes to cancer progression. NNMT is overexpressed in several cancers and promotes proinflammatory responses via the STAT3/IL1β/PGE2 pathway, while PRDX6 stabilizes NNMT to drive ovarian cancer progression. SETDB1 suppresses antitumor immunity, and its inhibition may enhance immune responses against tumors. These findings highlight N-methyltransferases as potential therapeutic targets in oncology.
N-methyltransferase activity in Pulmonary Hypertension
SMYD2-mediated methylation of PPARγ facilitates hypoxia-induced pulmonary hypertension by activating mitophagy. This modification alters PPARγ function, leading to pathological vascular remodeling. Targeting SMYD2 or its methylation of PPARγ could offer new therapeutic avenues for pulmonary hypertension.
N-methyltransferase activity in Inflammation
Calmodulin-lysine N-methyltransferase suppresses caspase-11 non-canonical inflammasome activation, thereby exerting anti-inflammatory effects. Conversely, NNMT aggravates proinflammatory responses through STAT3/IL1β/PGE2 signaling. These opposing roles illustrate the complexity of N-methyltransferase activity in inflammatory diseases.
N-methyltransferase activity in Tissue Regeneration and Metabolism
Stem cell activity-coupled suppression of endogenous retrovirus, involving N-methyltransferase activity, governs adult tissue regeneration. MLL4 controls skeletal muscle metabolic efficiency by limiting AMPK-mediated fuel catabolism, linking methylation to metabolic health. These roles suggest that N-methyltransferases are important for regenerative medicine and metabolic disorders.
From N-methyltransferase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of NNMT affect cancer cell proliferation? | NNMT knockout in ovarian cancer cell lines |
| Does SMYD2-mediated PPARγ methylation drive pulmonary hypertension? | Point mutation of PPARγ methylation site in endothelial cells |
| How does SETDB1 suppress antitumor immunity? | SETDB1 knockout in tumor cells followed by immune cell co-culture |
| What is the role of CaM KMT in inflammasome regulation? | CaM KMT knockout in macrophages |
| Does MLL4 regulate skeletal muscle metabolism? | Muscle-specific MLL4 knockout mice |
| Can NNMT overexpression promote inflammation? | NNMT overexpression in cell lines |
How to Study the N-methyltransferase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Methyltransferase assay | Enzymatic activity | Inhibitor screening; enzyme kinetics |
| RNA-seq | Transcriptional changes | Gene expression profiling upon KO/overexpression |
| ChIP-seq | Histone methylation marks | Epigenomic mapping of H3K4me1, H3K9me |
| Mass spectrometry | Methylated substrates | Substrate identification |
| Immunoprecipitation | Protein interactions | Complex formation (e.g., SETDB1-TRIM28) |
| Proliferation assay | Cell growth | Cancer cell response to NNMT modulation |
| Inflammasome assay | Caspase-11 activation | Anti-inflammatory effects of CaM KMT |
| Mitophagy assay | Autophagic flux | SMYD2-PPARγ axis in pulmonary hypertension |
Methyltransferase Activity Assays
Direct measurement of N-methyltransferase activity using radioactive or fluorescent SAM analogs, or by detecting methylated products via mass spectrometry. These assays are used to validate enzyme function and screen inhibitors.
Genomic and Epigenomic Profiling
RNA-seq and ChIP-seq to assess changes in gene expression and histone methylation marks (e.g., H3K4me1, H3K9me) upon manipulation of N-methyltransferases. These methods link enzyme activity to transcriptional outcomes.
Proteomics and Interactomics
Mass spectrometry-based proteomics to identify methylated substrates and interacting partners. For example, immunoprecipitation of SMYD2 followed by mass spectrometry can reveal PPARγ methylation. Proximity labeling can map enzyme-substrate networks.
Phenotypic and Functional Assays
Cell proliferation, migration, and immune cell activation assays to determine the biological consequences of N-methyltransferase activity. For instance, inflammasome activation assays in macrophages with CaM KMT knockout, or mitophagy assays in pulmonary hypertension models.
How CRISPR Can Be Used to Study GO:0008170 N-methyltransferase activity
Knockout
CRISPR knockout of N-methyltransferase genes (e.g., NNMT, SETDB1, CaM KMT) enables loss-of-function studies to determine their role in disease models. For example, SETDB1 knockout in tumor cells enhances antitumor immunity, and CaM KMT knockout increases inflammasome activation.
Point Mutation
Introducing point mutations in the catalytic domain or substrate-binding site of N-methyltransferases can dissect specific residues required for activity. For instance, mutating the PPARγ methylation site prevents SMYD2-mediated mitophagy in pulmonary hypertension.
Knock-in
Knock-in of tagged versions (e.g., FLAG, HA) of N-methyltransferases allows for affinity purification and interactome analysis. This approach can identify novel substrates and regulators, as demonstrated for SMYD2 and NNMT.
Overexpression
Overexpression of N-methyltransferases (e.g., NNMT) in cell lines can mimic disease states and reveal gain-of-function phenotypes, such as enhanced proinflammatory responses. This is useful for validating oncogenic roles and testing inhibitors.
How EDITGENE Supports N-methyltransferase activity Research
Researchers studying N-methyltransferase activity-related genes often need to determine whether a candidate gene is causally involved in a specific biological process or disease. EDITGENE provides comprehensive CRISPR-based services to accelerate this discovery, from gene knockout to precise point mutations and overexpression models.
Contact EDITGENE today to design your custom CRISPR model for N-methyltransferase activity research.
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| INMT Knockout HEK293 Cell Line | EDJ-KQ3926 | Human | 11185 | Details Get a Quote |
| HNMT Knockout HEK293 Cell Line | EDJ-KQ4886 | Human | 3176 | Details Get a Quote |
| SETD3 Knockout HEK293 Cell Line | EDJ-KQ10009 | Human | 84193 | Details Get a Quote |
| SETD3 Knockout HCT 116 Cell Line | EDJ-KQ36991 | Human | 84193 | Details Get a Quote |
| SETD3 Knockout HeLa Cell Line | EDJ-KQ36992 | Human | 84193 | Details Get a Quote |
| HNMT Knockout A-549 Cell Line | EDJ-KQ27691 | Human | 3176 | Details Get a Quote |
| HNMT Knockout HeLa Cell Line | EDJ-KQ27692 | Human | 3176 | Details Get a Quote |
| SETD3 Knockout A-549 Cell Line | EDJ-KQ35775 | Human | 84193 | Details Get a Quote |
| HEMK1 Knockout HEK293 Cell Line | EDJ-KQ51316 | Human | 51409 | Details Get a Quote |
| INMT Knockout HeLa Cell Line | EDJ-KQ55598 | Human | 11185 | Details Get a Quote |
| HEMK1 Knockout HeLa Cell Line | EDJ-KQ56307 | Human | 51409 | Details Get a Quote |
| INMT Knockout A-549 Cell Line | EDJ-KQ64094 | Human | 11185 | Details Get a Quote |
| HEMK1 Knockout A-549 Cell Line | EDJ-KQ64796 | Human | 51409 | Details Get a Quote |
| HNMT Knockout HCT 116 Cell Line | EDJ-KQ70489 | Human | 3176 | Details Get a Quote |
| INMT Knockout HCT 116 Cell Line | EDJ-KQ72544 | Human | 11185 | Details Get a Quote |
Displaying Records 1 To 15 Of 16 Records
Frequently Asked Questions About N-methyltransferase activity
What is N-methyltransferase activity?
N-methyltransferase activity (GO:0008170) is the catalysis of methyl group transfer to the nitrogen atom of an acceptor molecule, a modification involved in epigenetic regulation and metabolism.
What genes are involved in N-methyltransferase activity?
Key genes include CaM KMT, SMYD2, SETDB1, NNMT, and MLL4, each encoding enzymes that methylate specific substrates.
How is N-methyltransferase activity regulated?
It is regulated by enzyme expression, degradation (e.g., NNMT ubiquitination), complex formation (e.g., SETDB1-TRIM28), and substrate availability.
What diseases are associated with N-methyltransferase activity?
Dysregulation is linked to cancer, pulmonary hypertension, inflammatory diseases, and metabolic disorders.
How can I study N-methyltransferase activity in the lab?
Use methyltransferase assays, CRISPR knockout/knock-in models, RNA-seq, ChIP-seq, and proteomics to assess activity and downstream effects.
What is the role of NNMT in cancer?
NNMT remodels cell metabolism and aggravates proinflammatory responses, promoting ovarian cancer progression when stabilized by PRDX6.
How does SMYD2 contribute to pulmonary hypertension?
SMYD2 methylates PPARγ, activating mitophagy and facilitating hypoxia-induced pulmonary hypertension.
What is the function of SETDB1 in immunity?
SETDB1, as part of the SETDB1-TRIM28 complex, suppresses antitumor immunity by depositing repressive H3K9me marks.
Can CRISPR be used to study N-methyltransferase activity?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models enable precise dissection of gene function in disease contexts.
What methods measure N-methyltransferase activity?
Direct enzymatic assays, mass spectrometry, and methylated substrate detection are common; RNA-seq and ChIP-seq link activity to gene expression.
Conclusion
N-methyltransferase activity (GO:0008170) is a pivotal molecular function with broad implications in epigenetics, immunity, metabolism, and disease. The enzymes catalyzing this reaction, such as CaM KMT, SMYD2, SETDB1, NNMT, and MLL4, are emerging as key regulators of physiological and pathological processes. Understanding their mechanisms and regulation offers opportunities for therapeutic intervention in cancer, pulmonary hypertension, and inflammatory diseases. Leveraging CRISPR-based models and integrated omics approaches will continue to unravel the complexities of N-methyltransferase biology and accelerate the development of targeted therapies.
References
- 1. Cho HJ et al.. 2023. Anti-inflammatory activity of calmodulin-lysine N-methyltransferase through suppressing the caspase-11 non-canonical inflammasome.. Immunobiology 228(6):152758 PMID: 37948850
- 2. Li Y et al.. 2024. SMYD2-Methylated PPARγ Facilitates Hypoxia-Induced Pulmonary Hypertension by Activating Mitophagy.. Circ Res 135(1):93-109 PMID: 38770649
- 3. Kubo N et al.. 2024. H3K4me1 facilitates promoter-enhancer interactions and gene activation during embryonic stem cell differentiation.. Mol Cell 84(9):1742-1752.e5 PMID: 38513661
- 4. Lyu Y et al.. 2024. Stem cell activity-coupled suppression of endogenous retrovirus governs adult tissue regeneration.. Cell 187(26):7414-7432.e26 PMID: 39476839
- 5. Lin J et al.. 2021. The SETDB1-TRIM28 Complex Suppresses Antitumor Immunity.. Cancer Immunol Res 9(12):1413-1424 PMID: 34848497
- 6. Yang C et al.. 2022. Nicotinamide N-Methyltransferase Remodeled Cell Metabolism and Aggravated Proinflammatory Responses by Activating STAT3/IL1β/PGE(2) Pathway.. ACS Omega 7(42):37509-37519 PMID: 36312432
- 7. Wu X et al.. 2025. PRDX6 Prevents NNMT Ubiquitination and Degradation as a Nonenzymatic Mechanism to Promote Ovarian Cancer Progression.. Adv Sci (Weinh) 12(12):e2416484 PMID: 39887931
- 8. Yang L et al.. 2025. Enhancer regulator MLL4 controls skeletal muscle metabolic efficiency by limiting AMPK-mediated fuel catabolism.. Nat Commun 16(1):11644 PMID: 41298552
