GO:0032451 demethylase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0032451 demethylase activity is defined as catalysis of the removal of a methyl group from a substrate.
• Demethylases regulate chromatin, transcription, and signaling by erasing methyl marks on histones and other proteins.
• Key demethylase families include KDM5 (e.g., KDM5B, KDM5D) and LSD1/KDM1, which control gene expression and immune responses.
• Dysregulated demethylase activity is linked to cancer, viral pathogenesis, and inflammatory diseases.
• CRISPR knockout, point-mutation, knock-in, and overexpression models are essential to dissect demethylase function.
• Sensitive assays such as DNAzyme-based and CRISPR/Cas12a-coupled platforms enable profiling of demethylase activity.
Description
Demethylase activity (GO:0032451) is a molecular function that catalyzes the removal of a methyl group from a substrate, a reversible modification critical for dynamic regulation of chromatin and signaling. This activity is essential for controlling gene expression programs, cellular differentiation, and immune responses, and its dysregulation contributes to diseases such as cancer and viral infections. Researchers study demethylase activity to understand epigenetic regulation and to develop therapeutic strategies targeting these enzymes. The QuickGO definition provides a precise functional annotation: catalysis of the removal of a methyl group from a substrate. This article synthesizes current knowledge on the mechanisms, key genes, disease relevance, and research methods for demethylase activity, with a focus on experimental models and CRISPR-based approaches.
demethylase activity At A Glance
| GO ID | GO:0032451 |
|---|---|
| GO term | demethylase activity |
| Ontology | molecular_function |
| Synonym | none |
| Definition | Catalysis of the removal of a methyl group from a substrate. |
| Major function | Reversal of methylation on proteins and other substrates, regulating chromatin and signaling. |
| Representative enzymes | KDM5B, KDM5D, LSD1/KDM1, and other JmjC-domain or flavin-dependent demethylases. |
| Associated processes | Chromatin remodeling, transcriptional regulation, immune response, viral reactivation. |
| Disease relevance | Cancer, inflammatory diseases, viral pathogenesis. |
What Is GO:0032451?
In simple terms, demethylase activity means the ability of an enzyme to remove a methyl group from a target molecule. According to the Gene Ontology, GO:0032451 is defined as catalysis of the removal of a methyl group from a substrate. This activity is fundamental to epigenetic regulation, as it reverses methylation marks on histones and other proteins, thereby influencing gene transcription and cellular signaling.
Why Is demethylase activity Important in Cell Biology?
Demethylase activity is crucial because it provides a reversible switch for methylation-dependent signaling and gene regulation, allowing cells to adapt to developmental and environmental cues. Its dysregulation is implicated in cancer progression, immune evasion, and viral infections, making it a prime target for therapeutic intervention and a focus of intense research.
• Controls chromatin accessibility and gene expression by removing histone methyl marks.
• Regulates immune responses, including macrophage-mediated inflammation.
• Modulates viral lytic reactivation and oncogenesis, as shown for Epstein-Barr virus.
• Influences cancer progression through enzymes like KDM5D and LSD1.
• Serves as a biomarker and therapeutic target in multiple cancers.
• Enables dynamic reversibility of methylation in signaling pathways.
• Provides a mechanism for epigenetic plasticity in development and disease.
• Can be profiled with sensitive assays for drug discovery and diagnostics.
Molecular Mechanism of demethylase activity
Substrate recognition and binding
In simple terms: The enzyme first finds and grabs the methylated target.
Demethylases recognize specific methylated substrates, such as histone H3 lysine residues, through conserved domains. For example, KDM5B binds to methylated H3K4 to regulate transcription. The nuclear localization signal of LSD1 also contributes to its autoregulatory mechanism, ensuring proper substrate access.
Catalytic removal of the methyl group
In simple terms: The enzyme chemically removes the methyl group from the substrate.
Catalysis involves oxidative demethylation for JmjC-domain enzymes or flavin-dependent amine oxidation for LSD1. KDM5D mediates p38α inactivation via its enzymatic activity, demonstrating substrate-specific demethylation. LSD1 demethylase activity is inhibited by K63-linked ubiquitination by Trim35, highlighting regulatory control.
Cofactors and cofactor requirements
In simple terms: Some demethylases need helper molecules like iron or FAD to work.
JmjC-domain demethylases require Fe(II) and α-ketoglutarate, while LSD1 uses FAD as a cofactor. These cofactors are essential for catalytic activity and are often targeted in inhibitor design.
Regulation by post-translational modifications
In simple terms: The enzyme's activity can be turned on or off by other modifications.
Ubiquitination of LSD1 by Trim35 inhibits its demethylase activity, enhancing anti-tumor immunity in NSCLC. Autoregulatory mechanisms involving the nuclear localization signal also modulate LSD1 activity. Such modifications fine-tune demethylase function in response to cellular signals.
Downstream effects on gene expression
In simple terms: Removing methyl groups changes which genes are turned on or off.
Demethylation of histone marks alters chromatin structure and transcription. KDM5B represses Nfkbia transcription in macrophages, licensing inflammatory responses. In Epstein-Barr virus infection, histone demethylase machinery is hijacked to drive epithelial malignancy through KDM5B upregulation.
Key Genes Involved in GO:0032451 demethylase activity
The following genes encode demethylases or associated proteins that are central to the function and regulation of demethylase activity.
| Gene | Major Role | Research Relevance |
|---|---|---|
| KDM5B | Histone demethylase that removes methyl groups from H3K4 | Regulates macrophage inflammation and EBV-driven malignancy |
| KDM5D | Histone demethylase that inactivates p38α | Inhibits cancer progression via enzymatic activity |
| LSD1 (KDM1A) | Flavin-dependent demethylase of H3K4 and H3K9 | Targeted by Trim35 ubiquitination; regulates anti-tumor immunity |
| KDM1B | LSD1 homolog with demethylase activity | Potential role in epigenetic regulation (inferred from family) |
| JmjC-domain proteins | Fe(II)/α-KG-dependent demethylases | Broad family including KDM5 subfamily |
| Trim35 | E3 ligase that ubiquitinates LSD1 | Inhibits LSD1 demethylase activity in NSCLC |
| Nfkbia | Target gene repressed by KDM5B | Links demethylase activity to inflammatory signaling |
| p38α | Substrate inactivated by KDM5D | Tumor suppressor pathway |
| EBV proteins | Hijack demethylase machinery | Drive epithelial malignancy |
| H3K4me3 | Methylated histone substrate | Epigenetic mark removed by KDM5 enzymes |
| H3K9me2 | Methylated histone substrate | Substrate for LSD1 |
| FAD | Cofactor for LSD1 | Essential for catalytic activity |
| Fe(II)/α-KG | Cofactors for JmjC demethylases | Required for KDM5 activity |
| NLS | Nuclear localization signal | Autoregulates LSD1 activity |
| DNAzyme probes | Synthetic sensors of demethylase activity | Enable activity profiling |
| CRISPR/Cas12a | Amplification system for demethylase assays | Electrochemiluminescent detection |
How Is demethylase activity Regulated?
Demethylase activity is regulated at multiple levels. Post-translational modifications such as K63-linked ubiquitination by Trim35 directly inhibit LSD1 demethylase activity, enhancing anti-tumor immunity. Autoregulatory mechanisms involving the nuclear localization signal of LSD1 further control its enzymatic function. Additionally, cofactor availability (e.g., FAD, Fe(II), α-ketoglutarate) and substrate accessibility influence demethylase activity. Viral proteins can hijack demethylase machinery to promote oncogenesis, as seen with EBV-driven KDM5B upregulation.
demethylase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| KDM5B | Epithelial malignancy, inflammation | Knockout or overexpression in cancer cell lines and macrophages |
| KDM5D | Cancer progression | Point mutation of catalytic residues to assess enzymatic activity |
| LSD1 | NSCLC, anti-tumor immunity | Knockout and ubiquitination-site mutants |
| Trim35 | NSCLC | Overexpression and knockout to modulate LSD1 activity |
| EBV proteins | EBV-associated malignancies | Infection models with demethylase inhibitors |
Demethylase activity in cancer
Dysregulated demethylase activity contributes to cancer progression. KDM5D inhibits cancer progression by mediating p38α inactivation via its enzymatic activity. LSD1 demethylase activity is inhibited by Trim35, which enhances anti-tumor immunity in NSCLC. KDM5B upregulation driven by Epstein-Barr virus promotes epithelial malignancy, linking viral infection to epigenetic reprogramming.
Demethylase activity in viral pathogenesis
Epstein-Barr virus hijacks histone demethylase machinery to drive epithelial malignancy through KDM5B upregulation. Additionally, the lysine-specific histone demethylase complex restricts Epstein-Barr virus lytic reactivation, indicating a complex interplay between demethylase activity and viral life cycle.
Demethylase activity in inflammatory diseases
KDM5B licenses macrophage-mediated inflammatory responses by repressing Nfkbia transcription, thereby promoting inflammation. This highlights demethylase activity as a potential target for inflammatory diseases.
From demethylase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of demethylase activity affect tumor growth? | CRISPR knockout of KDM5D or LSD1 in cancer cell lines |
| Is catalytic activity required for function? | Point mutation of catalytic residues (e.g., KDM5D) |
| How does demethylase activity respond to signaling? | Knock-in of tagged demethylase for live-cell imaging |
| What are the downstream targets? | Overexpression followed by RNA-seq and ChIP-seq |
| Can demethylase activity be inhibited pharmacologically? | CRISPR/Cas12a-coupled activity assays |
| How does demethylase activity regulate inflammation? | Knockout of KDM5B in macrophages |
How to Study the demethylase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| DNAzyme-based assay | Demethylase activity via methylation-sensitive cleavage | Profiling enzyme activity in vitro |
| CRISPR/Cas12a electrochemiluminescence | Demethylase activity with signal amplification | Inhibitor screening |
| CRISPR knockout | Loss-of-function effects | Target validation in cancer cells |
| Point mutation | Catalytic activity requirement | Dissecting enzymatic vs. scaffolding functions |
| Knock-in tagging | Localization and dynamics | Live-cell imaging of demethylases |
| RNA-seq | Transcriptional changes | Identifying downstream targets |
| ChIP-seq | Chromatin occupancy and histone marks | Mapping demethylase binding sites |
| Ubiquitination assays | Post-translational regulation | Studying Trim35-LSD1 interaction |
Profiling demethylase activity with DNAzyme sensors
Epigenetically inactivated DNAzyme-based assays enable sensitive profiling of demethylase activity by coupling methylation-dependent cleavage to fluorescent or electrochemical readouts. These methods allow quantitative measurement of enzyme activity in vitro and in cell lysates.
CRISPR/Cas12a-coupled electrochemiluminescent assays
A circular DNAzyme-switched CRISPR/Cas12a assay provides electrochemiluminescent detection of demethylase activity, offering high sensitivity and specificity for inhibitor screening.
Genetic perturbation with CRISPR
CRISPR knockout, point mutation, and knock-in models are used to dissect the role of demethylase catalytic activity in cells. For example, point mutations in KDM5D catalytic domain abolish its ability to inactivate p38α. Knockout of LSD1 or KDM5B reveals effects on inflammation and tumor immunity.
Transcriptomic and epigenomic profiling
RNA-seq and ChIP-seq after demethylase perturbation identify downstream target genes and chromatin changes. KDM5B repression of Nfkbia was uncovered using such approaches. EBV-driven KDM5B upregulation was linked to epithelial malignancy through transcriptomic analyses.
How CRISPR Can Be Used to Study GO:0032451 demethylase activity
Knockout
CRISPR knockout of demethylase genes such as KDM5B, KDM5D, or LSD1 is used to assess loss-of-function phenotypes in cancer and immune cells. For example, KDM5B knockout in macrophages alters inflammatory responses.
Point Mutation
Point mutations in catalytic residues (e.g., KDM5D) abolish demethylase activity, allowing researchers to distinguish enzymatic from non-enzymatic functions. Such models are critical for target validation.
Knock-in
Knock-in of tagged demethylases (e.g., GFP or HA) enables visualization and immunoprecipitation to study localization and interactions. This approach can also introduce disease-associated mutations.
Overexpression
Overexpression of demethylases like KDM5B or LSD1 is used to model gain-of-function effects in cancer and inflammation. Overexpression combined with RNA-seq reveals downstream transcriptional programs.
How EDITGENE Supports demethylase activity Research
Researchers studying demethylase activity-related genes often need to determine whether a candidate gene is causally involved in a specific phenotype, and CRISPR-based models provide the most direct way to establish causality. EDITGENE offers a comprehensive suite of services to support such studies, from knockout to knock-in and library screening.
Contact EDITGENE today to design your custom CRISPR model for demethylase activity research.
Related Products
| Product name | Cat.No. | Species | Gene ID | |
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| MMACHC Knockout HEK293 Cell Line | EDC07667 | Human | 25974 | Details Get a Quote |
| CYP1A1 Knockout HEK293 Cell Line | EDJ-KQ3897 | Human | 1543 | Details Get a Quote |
| CYP1A2 Knockout HEK293 Cell Line | EDJ-KQ4399 | Human | 1544 | Details Get a Quote |
| ALKBH4 Knockout HEK293 Cell Line | EDJ-KQ11586 | Human | 54784 | Details Get a Quote |
| CYP1A1 Knockout HCT 116 Cell Line | EDJ-KQ26114 | Human | 1543 | Details Get a Quote |
| ALKBH4 Knockout A-549 Cell Line | EDJ-KQ41180 | Human | 54784 | Details Get a Quote |
| ALKBH4 Knockout HCT 116 Cell Line | EDJ-KQ41181 | Human | 54784 | Details Get a Quote |
| ALKBH4 Knockout HeLa Cell Line | EDJ-KQ41182 | Human | 54784 | Details Get a Quote |
| MMACHC Knockout A-549 Cell Line | EDJ-KQ24227 | Human | 25974 | Details Get a Quote |
| MMACHC Knockout HCT 116 Cell Line | EDJ-KQ24228 | Human | 25974 | Details Get a Quote |
| MMACHC Knockout HeLa Cell Line | EDJ-KQ24229 | Human | 25974 | Details Get a Quote |
| CYP1A1 Knockout HeLa Cell Line | EDJ-KQ53039 | Human | 1543 | Details Get a Quote |
| CYP1A2 Knockout HeLa Cell Line | EDJ-KQ53040 | Human | 1544 | Details Get a Quote |
| CYP1A1 Knockout A-549 Cell Line | EDJ-KQ61503 | Human | 1543 | Details Get a Quote |
| CYP1A2 Knockout A-549 Cell Line | EDJ-KQ61504 | Human | 1544 | Details Get a Quote |
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Frequently Asked Questions About demethylase activity
What is demethylase activity?
Demethylase activity (GO:0032451) is the catalysis of the removal of a methyl group from a substrate, a key epigenetic regulatory function.
What genes are involved in demethylase activity?
Key genes include KDM5B, KDM5D, LSD1/KDM1A, and other JmjC-domain or flavin-dependent demethylases.
How is demethylase activity measured?
It can be measured using DNAzyme-based assays, CRISPR/Cas12a-coupled electrochemiluminescence, or traditional biochemical assays.
What diseases are linked to demethylase activity?
Cancer, inflammatory diseases, and viral infections such as Epstein-Barr virus-associated malignancies.
What is the role of KDM5B in inflammation?
KDM5B represses Nfkbia transcription, thereby licensing macrophage-mediated inflammatory responses.
How does LSD1 demethylase activity get regulated?
LSD1 activity is inhibited by K63-linked ubiquitination by Trim35 and autoregulated by its nuclear localization signal.
Can CRISPR be used to study demethylase activity?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are widely used to dissect demethylase function.
What is the connection between demethylase activity and cancer?
Demethylases like KDM5D and LSD1 can inhibit or promote cancer progression, and their dysregulation is common in malignancies.
How does Epstein-Barr virus affect demethylase activity?
EBV hijacks histone demethylase machinery, including KDM5B upregulation, to drive epithelial malignancy.
What are the cofactors for demethylase activity?
JmjC-domain demethylases require Fe(II) and α-ketoglutarate, while LSD1 uses FAD.
Conclusion
Demethylase activity (GO:0032451) is a fundamental molecular function that reverses methylation on diverse substrates, with critical roles in chromatin regulation, immunity, and disease. Key enzymes such as KDM5B, KDM5D, and LSD1 are implicated in cancer, inflammation, and viral pathogenesis, making them attractive therapeutic targets. Advances in CRISPR-based models and sensitive activity assays continue to accelerate our understanding of demethylase biology and its translational potential.
References
- 1. Huang J et al.. 2022. Profiling demethylase activity using epigenetically inactivated DNAzyme.. Biosens Bioelectron 207:114186 PMID: 35316758
- 2. Liao Y et al.. 2025. Lysine-specific histone demethylase complex restricts Epstein-Barr virus lytic reactivation.. Nat Microbiol 10(12):3290-3304 PMID: 41174223
- 3. Zhou YQ et al.. 2025. Epstein-Barr virus hijacks histone demethylase machinery to drive epithelial malignancy progression through KDM5B upregulation.. Signal Transduct Target Ther 10(1):83 PMID: 40059116
- 4. Zhang Y et al.. 2023. Histone demethylase KDM5B licenses macrophage-mediated inflammatory responses by repressing Nfkbia transcription.. Cell Death Differ 30(5):1279-1292 PMID: 36914768
- 5. Chen J et al.. 2024. KDM5D histone demethylase mediates p38α inactivation via its enzymatic activity to inhibit cancer progression.. Proc Natl Acad Sci U S A 121(50):e2402022121 PMID: 39636854
- 6. Yang WW et al.. 2024. Circular DNAzyme-Switched CRISPR/Cas12a Assay for Electrochemiluminescent Response of Demethylase Activity.. ACS Sens 9(1):344-350 PMID: 38198738
- 7. Tang F et al.. 2023. E3 ligase Trim35 inhibits LSD1 demethylase activity through K63-linked ubiquitination and enhances anti-tumor immunity in NSCLC.. Cell Rep 42(12):113477 PMID: 37979167
- 8. Senanayaka D et al.. 2024. Autoregulatory mechanism of enzyme activity by the nuclear localization signal of lysine-specific demethylase 1.. J Biol Chem 300(9):107607 PMID: 39084460
