GO:0140945 histone H3K4 monomethyltransferase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0140945 defines the enzymatic activity that adds a single methyl group to lysine 4 of histone H3, producing H3K4me1, a key chromatin mark for enhancers and gene regulation.
• The reaction uses S-adenosyl-L-methionine (SAM) as the methyl donor and releases S-adenosyl-L-homocysteine (SAH).
• Key enzymes include KMT2C, KMT2D, SETD7, and the Drosophila Trithorax protein, which monomethylate H3K4 and interact with coactivators such as CBP.
• H3K4 monomethylation is enriched at enhancers and is linked to transcriptional activation, development, and cancer.
• Dysregulation of H3K4 monomethyltransferases is implicated in cancer, osteogenic disorders, and developmental defects.
• CRISPR-based knockout, point mutation, knock-in, and overexpression models are essential to dissect the causal roles of these enzymes in health and disease.
Description
Histone H3K4 monomethyltransferase activity (GO:0140945) is a molecular function that catalyzes the transfer of a single methyl group from S-adenosyl-L-methionine (SAM) to the unmethylated lysine 4 of histone H3, generating H3K4me1. This modification is a hallmark of enhancer regions and plays a critical role in gene regulation, development, and disease. Unlike di- and trimethylation, monomethylation is often associated with poised or active enhancers and is dynamically regulated by a family of SET-domain-containing enzymes. Researchers study this activity to understand how chromatin states are established and how mutations in the responsible enzymes contribute to cancer and other disorders. The reaction is highly specific and requires a conserved catalytic domain, making it an attractive target for therapeutic intervention and functional genomics.
histone H3K4 monomethyltransferase activity At A Glance
| GO ID | GO:0140945 |
|---|---|
| GO term | histone H3K4 monomethyltransferase activity |
| Ontology | molecular_function |
| Synonym | histone H3K4 monomethylase activity, histone H4-K4 methylation, histone H4K4 methylation, histone lysine N-monomethyltransferase activity (H3-K4 specific) |
| Major function | Catalyzes the addition of a single methyl group to histone H3 lysine 4 using SAM as a methyl donor, producing H3K4me1 and SAH. |
| Reaction | L-lysyl4-[histone H3] + S-adenosyl-L-methionine = H+ + N6-methyl-L-lysyl4-[histone H3] + S-adenosyl-L-homocysteine |
| Cofactor | S-adenosyl-L-methionine (SAM) |
| Product | Histone H3K4 monomethylated (H3K4me1) |
| Localization | Nucleus, chromatin |
What Is GO:0140945?
GO:0140945 describes the catalysis of the reaction: L-lysyl4-[histone H3] + S-adenosyl-L-methionine = H+ + N6-methyl-L-lysyl4-[histone H3] + S-adenosyl-L-homocysteine. In simpler terms, it is the addition of a single methyl group to the unmethylated lysine residue at position 4 of histone H3, producing histone H3K4me (monomethylated H3K4). This activity is distinct from di- and trimethylation and is often mediated by enzymes such as KMT2C, KMT2D, and SETD7.
Why Is histone H3K4 monomethyltransferase activity Important in Cell Biology?
Histone H3K4 monomethyltransferase activity is crucial for establishing enhancer landscapes and regulating gene expression programs during development and differentiation. It serves as a priming step for further methylation and is essential for the recruitment of coactivators such as CBP, which acetylates H3K27 to promote active chromatin. Dysregulation of this activity is linked to various cancers, including those driven by MLL4/COMPASS mutations, and to developmental disorders. Understanding this activity provides insights into epigenetic mechanisms and offers potential therapeutic targets.
• Regulates enhancer activity and gene expression programs.
• Priming step for H3K4 di- and trimethylation, influencing chromatin states.
• Interacts with CBP to promote H3K27 acetylation and antagonize Polycomb silencing.
• Mutations in KMT2C/KMT2D are frequent in cancer and create druggable vulnerabilities.
• SETD7-mediated H3K4 monomethylation promotes osteogenic differentiation and is affected by hydroquinone exposure.
• Mutant p53 can regulate enhancer-associated H3K4 monomethylation through MLL4.
• Somatic mutations in MLL4/COMPASS alter its localization and impact cancer prognosis.
• Plays a role in p53-dependent transcription activation.
• Involved in developmental processes and stem cell differentiation.
• Potential target for epigenetic therapies in cancer and regenerative medicine.
Molecular Mechanism of histone H3K4 monomethyltransferase activity
Substrate Recognition and Binding
In simple terms: The enzyme finds and binds to histone H3, specifically at lysine 4.
The monomethyltransferase enzymes contain a SET domain that recognizes the N-terminal tail of histone H3, with specificity for lysine 4. The PHD finger cluster within the MLR family of H3K4 mono-methyltransferases contributes to histone binding and target specificity. This binding is essential for positioning the lysine residue for catalysis.
Catalytic Methyl Transfer
In simple terms: The enzyme transfers a methyl group from SAM to lysine 4.
Using S-adenosyl-L-methionine (SAM) as the methyl donor, the enzyme catalyzes the transfer of a single methyl group to the epsilon-amino group of lysine 4, producing H3K4me1 and S-adenosyl-L-homocysteine (SAH). This reaction is highly specific and requires a conserved catalytic domain.
Product Release and Chromatin Modification
In simple terms: After adding the methyl group, the enzyme releases the modified histone and SAH.
Following catalysis, the monomethylated H3K4 (H3K4me1) remains on the chromatin and serves as a mark for enhancer regions. The enzyme releases SAH, which can be recycled to SAM. H3K4me1 can be further methylated by other enzymes to H3K4me2/3, but the monomethylation step is distinct.
Interaction with Coactivators and Regulatory Complexes
In simple terms: The enzyme works with other proteins to activate genes.
H3K4 monomethyltransferases such as Trithorax interact directly with CBP to promote H3K27 acetylation, antagonizing Polycomb silencing. MLL4 (KMT2D) is part of the COMPASS complex and interacts with p53 to activate transcription. These interactions couple H3K4 monomethylation to transcriptional activation.
Regulation by Cellular Signals and Mutations
In simple terms: The activity can be turned on or off by cellular signals and is altered in disease.
Mutant p53 can regulate enhancer-associated H3K4 monomethylation through interactions with MLL4. Somatic mutations in MLL4/COMPASS can induce cytoplasmic localization, affecting its function and cancer prognosis. Additionally, SETD7 activity is modulated during osteogenic differentiation and by environmental factors like hydroquinone.
Key Genes Involved in GO:0140945 histone H3K4 monomethyltransferase activity
The following genes encode enzymes or subunits that possess or regulate histone H3K4 monomethyltransferase activity.
| Gene | Major Role | Research Relevance |
|---|---|---|
| KMT2C (MLL3) | H3K4 monomethyltransferase in COMPASS complex | Frequently mutated in cancer; enhancer regulation |
| KMT2D (MLL4) | H3K4 monomethyltransferase in COMPASS complex | Mutated in Kabuki syndrome and cancer; interacts with p53 |
| SETD7 (SET7/9) | H3K4 monomethyltransferase | Promotes osteogenic differentiation; affected by hydroquinone |
| Trithorax (Drosophila) | H3K4 monomethyltransferase | Interacts with CBP to antagonize Polycomb silencing |
| CBP (CREBBP) | Histone acetyltransferase, interacts with Trithorax | Promotes H3K27 acetylation |
| p53 (TP53) | Transcription factor, interacts with MLL4 | Mutant p53 regulates H3K4 monomethylation |
| WDR5 | Core subunit of COMPASS-like complexes | Required for H3K4 methylation |
| RBBP5 | Core subunit of COMPASS-like complexes | Required for H3K4 methylation |
| ASH2L | Core subunit of COMPASS-like complexes | Required for H3K4 methylation |
| DPY30 | Core subunit of COMPASS-like complexes | Required for H3K4 methylation |
| KMT2A (MLL1) | H3K4 methyltransferase | Related family member, often studied in leukemia |
| KMT2B (MLL2) | H3K4 methyltransferase | Related family member, involved in development |
| SETD1A | H3K4 methyltransferase | Related family member, involved in transcription |
| SETD1B | H3K4 methyltransferase | Related family member, involved in transcription |
| PAX7 | Transcription factor | May recruit H3K4 monomethyltransferases |
| MYOD1 | Transcription factor | May recruit H3K4 monomethyltransferases |
| CTNNB1 (β-catenin) | Transcription coactivator | May interact with H3K4 monomethyltransferases |
How Is histone H3K4 monomethyltransferase activity Regulated?
Histone H3K4 monomethyltransferase activity is regulated at multiple levels. The enzymes are recruited to specific genomic loci by transcription factors and coactivators, such as p53 and CBP. Their activity can be modulated by post-translational modifications and interactions with other subunits of the COMPASS complex. Mutations in the enzymes themselves, such as in KMT2C and KMT2D, can alter their localization and function, as seen in cancer. Additionally, environmental factors like hydroquinone can affect SETD7-mediated H3K4 monomethylation during osteogenic differentiation.
histone H3K4 monomethyltransferase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| KMT2C | Cancer (various solid tumors) | Knockout in cancer cell lines; xenograft models |
| KMT2D | Kabuki syndrome, cancer | Knockout and point mutation in iPSCs; mouse models |
| SETD7 | Osteogenic differentiation, bone disorders | Knockout in mesenchymal stem cells; hydroquinone exposure |
| TP53 | Cancer (mutant p53) | Knock-in of mutant p53 in cancer cells; enhancer profiling |
| MLL4/COMPASS | Cancer prognosis | Overexpression of mutant MLL4; cytoplasmic localization studies |
Cancer
Mutations in KMT2C and KMT2D, which encode H3K4 monomethyltransferases, are frequent in various cancers and are associated with poor prognosis. Somatic mutations in MLL4/COMPASS can induce cytoplasmic localization, providing molecular insight into cancer prognosis and treatment. Mutant p53 can hijack MLL4 to regulate enhancer-associated H3K4 monomethylation, contributing to oncogenic transcription programs.
Developmental Disorders
KMT2D mutations cause Kabuki syndrome, a developmental disorder characterized by intellectual disability and distinct facial features. The role of H3K4 monomethylation in enhancer regulation is critical for normal development, and its disruption leads to developmental defects.
Bone and Metabolic Disorders
SETD7-mediated H3K4 monomethylation promotes osteogenic differentiation of bone marrow mesenchymal stem cells, and exposure to hydroquinone impairs this process via autophagy. This suggests a role for H3K4 monomethyltransferases in bone metabolism and environmental toxicity.
From histone H3K4 monomethyltransferase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of KMT2C affect enhancer H3K4me1 and gene expression? | KMT2C knockout cell line (e.g., CRISPR-Cas9) |
| Does a specific point mutation in KMT2D alter its methyltransferase activity? | Point mutation knock-in via CRISPR |
| Can wild-type KMT2D rescue developmental defects? | Knock-in of tagged KMT2D in knockout background |
| What is the effect of SETD7 overexpression on osteogenesis? | Overexpression of SETD7 in mesenchymal stem cells |
| How does mutant p53 interact with MLL4 at enhancers? | Knock-in of mutant p53; ChIP-seq for H3K4me1 |
| Does MLL4 cytoplasmic localization contribute to cancer? | Overexpression of mutant MLL4 with cytoplasmic tag |
How to Study the histone H3K4 monomethyltransferase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| ChIP-seq | Genome-wide localization of H3K4me1 | Mapping enhancers; assessing changes upon knockout |
| Mass spectrometry | Histone modification quantification | Detecting H3K4me1 levels and interacting proteins |
| In vitro methyltransferase assay | Enzymatic activity | Measuring catalytic activity of recombinant enzymes |
| CRISPR knockout | Loss-of-function effects | Determining gene requirement for H3K4me1 |
| CRISPR point mutation | Specific amino acid changes | Dissecting catalytic domain function |
| CRISPR knock-in | Tagged or mutant protein expression | Studying localization and interactions |
| RNA-seq | Transcriptional changes | Linking H3K4me1 to gene expression |
| ATAC-seq | Chromatin accessibility | Correlating H3K4me1 with open chromatin |
Chromatin Immunoprecipitation Sequencing (ChIP-seq)
ChIP-seq using antibodies against H3K4me1 is the gold standard to map monomethylation marks across the genome, revealing enhancer landscapes. It can be combined with knockout or overexpression models to assess the impact of specific enzymes.
Mass Spectrometry-Based Proteomics
Mass spectrometry can quantify histone modifications, including H3K4me1, and identify interacting proteins in COMPASS complexes. This method provides stoichiometric information and can detect changes in response to mutations.
In Vitro Methyltransferase Assays
Recombinant enzymes or immunoprecipitated complexes can be incubated with histone substrates and SAM to measure methyltransferase activity directly. Radioactive or fluorescent SAM analogs allow quantification.
CRISPR-Based Functional Genomics
CRISPR knockout, point mutation, and knock-in models enable causal testing of specific genes in H3K4 monomethylation and downstream phenotypes. Pooled CRISPR screens can identify modifiers of H3K4me1 levels.
How CRISPR Can Be Used to Study GO:0140945 histone H3K4 monomethyltransferase activity
Knockout
CRISPR knockout of H3K4 monomethyltransferase genes such as KMT2C, KMT2D, or SETD7 allows researchers to assess their necessity for H3K4me1 deposition and downstream phenotypes. Knockout cell lines can be used for ChIP-seq, RNA-seq, and functional assays.
Point Mutation
Introducing point mutations in the catalytic SET domain of KMT2D or SETD7 via CRISPR can separate enzymatic activity from scaffolding functions. This helps determine whether monomethylation is required for specific biological processes.
Knock-in
Knock-in of tagged or mutant versions of H3K4 monomethyltransferases (e.g., GFP-tagged KMT2D) enables live-cell imaging and proteomic studies. Knock-in of disease-associated mutations can model their effects on chromatin.
Overexpression
Overexpression of wild-type or mutant enzymes (e.g., SETD7, MLL4) can reveal gain-of-function effects on H3K4me1 and gene expression. This is particularly useful for studying oncogenic roles.
How EDITGENE Supports histone H3K4 monomethyltransferase activity Research
Researchers studying histone H3K4 monomethyltransferase activity-related genes often need to determine whether a candidate gene is causally involved in H3K4me1 deposition, enhancer regulation, or disease phenotypes. EDITGENE provides a comprehensive suite of CRISPR services to enable such investigations with precision and reproducibility.
Contact EDITGENE today to design your custom CRISPR model for histone H3K4 monomethyltransferase activity research.
Frequently Asked Questions About histone H3K4 monomethyltransferase activity
What is histone H3K4 monomethyltransferase activity?
It is the enzymatic activity that adds a single methyl group to lysine 4 of histone H3, producing H3K4me1, as defined by GO:0140945.
What genes are involved in histone H3K4 monomethyltransferase activity?
Key genes include KMT2C, KMT2D, SETD7, and the Drosophila Trithorax gene, among others.
What is the difference between H3K4 mono-, di-, and trimethylation?
Monomethylation adds one methyl group, while di- and trimethylation add two or three, respectively; they are catalyzed by distinct enzymes and have different genomic distributions.
How is H3K4 monomethylation linked to cancer?
Mutations in KMT2C and KMT2D are frequent in cancer and can alter enhancer landscapes and gene expression, contributing to tumorigenesis.
What diseases are associated with H3K4 monomethyltransferase mutations?
Kabuki syndrome (KMT2D), various cancers (KMT2C/D), and bone disorders (SETD7) have been linked to dysregulation of this activity.
What methods are used to study H3K4 monomethyltransferase activity?
ChIP-seq, mass spectrometry, in vitro methyltransferase assays, and CRISPR-based models are commonly used.
Can CRISPR be used to study H3K4 monomethyltransferase activity?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are powerful tools to dissect gene function.
What is the role of SETD7 in H3K4 monomethylation?
SETD7 monomethylates H3K4 and promotes osteogenic differentiation; its activity is affected by hydroquinone.
How does MLL4 regulate H3K4 monomethylation?
MLL4 (KMT2D) is a subunit of COMPASS that monomethylates H3K4 and interacts with p53 to activate transcription.
What are the potential therapeutic implications of targeting H3K4 monomethyltransferases?
Inhibitors or modulators could be developed for cancer and developmental disorders, though further research is needed.
Conclusion
Histone H3K4 monomethyltransferase activity (GO:0140945) is a fundamental epigenetic function that shapes enhancer landscapes and gene expression. Its dysregulation is implicated in cancer, developmental disorders, and bone diseases. Understanding the enzymes and mechanisms involved provides opportunities for therapeutic intervention. EDITGENE offers comprehensive CRISPR solutions to study these processes with precision.
References
- 1. Shen Y et al.. 2026. Histone H3K4 monomethyltransferase SETD7 promoted osteogenic differentiation of bone marrow mesenchymal stem cells exposed to Hydroquinone via autophagy.. Toxicol Lett 418:111863 PMID: 41740875
- 2. Sun J et al.. 2026. Molecular mechanisms of the MLL4 complex in H3K4 methylation and p53-dependent transcription activation.. Mol Cell 86(12):2281-2293.e7 PMID: 42214331
- 3. Froimchuk E et al.. 2017. Histone H3 lysine 4 methyltransferase KMT2D.. Gene 627:337-342 PMID: 28669924
- 4. Tie F et al.. 2014. Trithorax monomethylates histone H3K4 and interacts directly with CBP to promote H3K27 acetylation and antagonize Polycomb silencing.. Development 141(5):1129-39 PMID: 24550119
- 5. Rahnamoun H et al.. 2018. Mutant p53 regulates enhancer-associated H3K4 monomethylation through interactions with the methyltransferase MLL4.. J Biol Chem 293(34):13234-13246 PMID: 29954944
- 6. Zraly CB et al.. 2023. New twists of a TAIL: novel insights into the histone binding properties of a highly conserved PHD finger cluster within the MLR family of H3K4 mono-methyltransferases.. Nucleic Acids Res 51(18):9672-9689 PMID: 37638761
- 7. Zhao Z et al.. 2026. Enhancer and metabolic rewiring by KMT2C-COMPASS or KMT2D-COMPASS family loss in cancer creates druggable vulnerabilities.. Nat Rev Cancer 26(6):437-451 PMID: 42032161
- 8. Zhao Z et al.. 2023. Somatic mutations of MLL4/COMPASS induce cytoplasmic localization providing molecular insight into cancer prognosis and treatment.. Proc Natl Acad Sci U S A 120(52):e2310063120 PMID: 38113256
