GO:0140944 histone H4K20 monomethyltransferase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0140944 describes the enzymatic activity that transfers a single methyl group from S-adenosyl-L-methionine to lysine 20 of histone H4, producing histone H4K20me.
• SETD8 (also known as PR-Set7, KMT5A) is the principal enzyme responsible for histone H4K20 monomethylation in human cells.
• H4K20me is essential for mitotic entry, genomic stability, DNA damage repair, and replication licensing.
• Loss of SETD8 catalytic activity causes mitotic defects, DNA damage accumulation, and impaired 53BP1 recruitment to double-strand breaks.
• SETD8-mediated H4K20me influences chromatin accessibility and has been linked to herpes simplex virus genome regulation and colorectal cancer suppression.
• CRISPR knockout, point-mutation, knock-in, and overexpression models are key tools for dissecting H4K20 monomethyltransferase function in health and disease.
Description
Histone H4 lysine 20 monomethylation (H4K20me) is a chromatin modification catalyzed by the enzyme annotated under Gene Ontology term GO:0140944, histone H4K20 monomethyltransferase activity. This activity adds a single methyl group to the unmethylated lysine 20 residue of histone H4 using S-adenosyl-L-methionine as the methyl donor, generating H4K20me and S-adenosyl-L-homocysteine. The reaction is distinct from di- and trimethylation of H4K20, which are carried out by different enzymes and have distinct biological readouts. Researchers study GO:0140944 because H4K20me is a critical epigenetic mark that regulates mitotic entry, genomic stability, DNA damage repair, and replication licensing. The principal enzyme responsible for this activity in humans is SETD8 (also called PR-Set7 or KMT5A), a SET-domain-containing methyltransferase. Beyond its canonical role in chromatin, SETD8 has been reported to methylate non-histone substrates such as YAP, linking H4K20 monomethyltransferase activity to colorectal cancer suppression. The modification also influences global chromatin accessibility during herpes simplex virus infection, highlighting its broad impact on genome regulation. Understanding GO:0140944 therefore requires integrating structural, biochemical, and cellular approaches, with CRISPR-based models playing an increasingly central role.
histone H4K20 monomethyltransferase activity At A Glance
| GO ID | GO:0140944 |
|---|---|
| GO term | histone H4K20 monomethyltransferase activity |
| Ontology | molecular_function |
| Synonym | histone H4K20 methylase activity; histone H4-K20 methylation; histone H4K20 methylation; histone H4K20 monomethylation; histone lysine N-monomethyltransferase activity (H4-K20 specific) |
| Major function | Catalyzes the transfer of a methyl group from S-adenosyl-L-methionine to lysine 20 of histone H4, producing H4K20me and S-adenosyl-L-homocysteine |
| Principal enzyme | SETD8 (PR-Set7, KMT5A) |
| Substrate | Unmethylated lysine 20 of histone H4 |
| Cofactor | S-adenosyl-L-methionine (SAM) as methyl donor |
| Product | Histone H4K20me (monomethylated H4) and S-adenosyl-L-homocysteine |
| Biological context | Mitotic entry, genomic stability, DNA damage repair, replication licensing, chromatin accessibility |
What Is GO:0140944?
GO:0140944, histone H4K20 monomethyltransferase activity, is a molecular function defined as the catalysis of the reaction: L-lysyl20-[histone H4] + S-adenosyl-L-methionine = H+ + N6-methyl-L-lysyl20-[histone H4] + S-adenosyl-L-homocysteine. In simpler terms, it is the enzyme activity that attaches one methyl group to the twentieth lysine residue of histone H4, producing the monomethylated form known as H4K20me. This activity is specific for the unmethylated substrate and does not describe the subsequent di- or trimethylation steps, which are catalyzed by other enzymes such as SUV420H1 and SUV420H2. The reaction uses S-adenosyl-L-methionine as the methyl donor and releases S-adenosyl-L-homocysteine as a byproduct. The official synonyms include histone H4K20 methylase activity, histone H4-K20 methylation, histone H4K20 methylation, histone H4K20 monomethylation, and histone lysine N-monomethyltransferase activity (H4-K20 specific).
Why Is histone H4K20 monomethyltransferase activity Important in Cell Biology?
GO:0140944 is important because the monomethylation of histone H4 at lysine 20 is a foundational epigenetic mark that governs chromatin structure and genome maintenance. SETD8, the primary enzyme for this activity, is essential for mitotic entry and genomic stability; its loss leads to mitotic defects and DNA damage accumulation. The mark also serves as a prerequisite for subsequent di- and trimethylation by SUV420H enzymes, which are required for 53BP1 recruitment and non-homologous end joining at DNA double-strand breaks. In addition, SETD8-mediated H4K20me regulates replication licensing through a mechanism that depends on Suv4-20h. Beyond these canonical roles, SETD8 has been implicated in viral genome accessibility and in cancer suppression through methylation of non-histone targets such as YAP. Consequently, understanding GO:0140944 is critical for researchers in epigenetics, cancer biology, virology, and genome stability.
• Essential for mitotic entry and genomic stability; loss of SETD8 catalytic activity causes mitotic defects.
• Required for DNA damage repair, particularly 53BP1 nucleation and NHEJ-directed repair at double-strand breaks.
• Regulates replication licensing in a manner dependent on Suv4-20h.
• Influences global chromatin accessibility during herpes simplex virus infection.
• Linked to colorectal cancer suppression via SETD8-mediated monomethylation of YAP at K76.
• Plays a role in DNA damage repair pathways as reviewed for the methyltransferase SETD8.
• Establishes a repressive trans-tail histone code that regulates differentiation.
• Its activity is coordinated with CRL4(Cdt2) ubiquitin ligase, a genome caretaker controlled by Cdt2 binding to PCNA and DNA.
• Serves as a biomarker and potential therapeutic target in cancers with dysregulated H4K20me.
• Provides a paradigm for studying crosstalk between histone methylation and non-histone substrate methylation.
What Happens During histone H4K20 monomethyltransferase activity?
Substrate recognition and binding
In simple terms: The enzyme first finds and grabs the histone H4 protein at the right spot.
The monomethyltransferase SETD8 recognizes the N-terminal tail of histone H4, specifically the unmethylated lysine 20 residue. This recognition is mediated by the SET domain of SETD8, which forms a binding pocket for the histone H4 tail. The enzyme must distinguish unmethylated H4K20 from already methylated forms to ensure monomethylation specificity. Structural and biochemical studies indicate that the catalytic domain of SETD8 is essential for this substrate binding and for subsequent methyl transfer.
Methyl group transfer from SAM
In simple terms: The enzyme takes a methyl group from a donor molecule and attaches it to the histone.
Once bound to histone H4, SETD8 catalyzes the transfer of a methyl group from S-adenosyl-L-methionine (SAM) to the epsilon-amino group of lysine 20. This reaction produces the monomethylated histone H4K20me and releases S-adenosyl-L-homocysteine (SAH) as a byproduct. The catalytic mechanism involves deprotonation of the lysine residue and nucleophilic attack on the methyl group of SAM. This step is the defining biochemical event of GO:0140944.
Product formation and chromatin incorporation
In simple terms: The newly modified histone becomes part of chromatin and sends signals to other proteins.
After monomethylation, H4K20me is incorporated into nucleosomes and serves as a docking site for reader proteins. The mark is a prerequisite for subsequent di- and trimethylation by SUV420H1 and SUV420H2, which generate H4K20me2 and H4K20me3. These higher methylation states are required for the recruitment of 53BP1 to DNA double-strand breaks and for efficient non-homologous end joining. Thus, the monomethylation event catalyzed by GO:0140944 is the first step in a methylation cascade that regulates genome stability.
Cell cycle coupling and regulation
In simple terms: The enzyme works at specific times in the cell cycle to ensure proper cell division.
SETD8 activity peaks during S phase and mitosis, and its catalytic function is essential for mitotic entry. Loss of SETD8 activity leads to mitotic defects, including chromosome missegregation and genomic instability. The enzyme is also regulated by CRL4(Cdt2) ubiquitin ligase, which controls its abundance in a PCNA- and DNA-dependent manner. This cell cycle coupling ensures that H4K20 monomethylation is temporally coordinated with DNA replication and chromosome segregation.
Key Genes Involved in GO:0140944 histone H4K20 monomethyltransferase activity
The following genes and proteins are directly involved in or regulate histone H4K20 monomethyltransferase activity (GO:0140944) and its downstream biological processes.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SETD8 (KMT5A, PR-Set7) | Principal histone H4K20 monomethyltransferase; catalyzes the reaction of GO:0140944 | Essential for mitotic entry, genomic stability, and DNA damage repair |
| SUV420H1 (KMT5B) | Di- and trimethyltransferase that converts H4K20me to H4K20me2/3 | Required for 53BP1 recruitment and NHEJ at double-strand breaks |
| SUV420H2 (KMT5C) | Di- and trimethyltransferase that converts H4K20me to H4K20me2/3 | Cooperates with SETD8 in DNA damage repair and replication licensing |
| YAP | Non-histone substrate monomethylated by SETD8 at K76 | Monomethylation promotes K48-linked polyubiquitination and degradation, suppressing colorectal cancer |
| CRL4(Cdt2) | Ubiquitin ligase that regulates SETD8 abundance | Controls SETD8 stability in a PCNA- and DNA-dependent manner |
| PCNA | DNA sliding clamp that binds Cdt2 | Required for CRL4(Cdt2)-mediated regulation of SETD8 |
| 53BP1 | Reader of H4K20me2 that nucleates at DNA double-strand breaks | Its recruitment depends on concerted H4K20 methylation by SETD8 and SUV420H enzymes |
| Histone H4 | Substrate for monomethylation at lysine 20 | The direct target of GO:0140944 |
| S-adenosyl-L-methionine (SAM) | Methyl donor cofactor | Required for the catalytic reaction of GO:0140944 |
| S-adenosyl-L-homocysteine (SAH) | Byproduct of the methylation reaction | Feedback inhibitor of methyltransferases |
| HSV-1 genome | Target of SETD8-mediated chromatin accessibility | SETD8 promotes global accessibility of infecting herpes simplex virus genomes |
| CDT2 | Substrate receptor of CRL4 ubiquitin ligase | Binds PCNA and DNA to control SETD8 degradation |
| PR-Set7 (Drosophila homolog) | Establishes repressive trans-tail histone code | Regulates differentiation through H4K20me |
| Suv4-20h (Drosophila homolog) | Di- and trimethyltransferase | Required for PR-Set7 function in replication licensing |
| KMT5A (alternative name for SETD8) | Histone lysine methyltransferase | Catalyzes H4K20 monomethylation |
| H4K20me reader proteins | Interpret the monomethyl mark | Mediate downstream effects on chromatin structure and repair |
| DNA damage response proteins | Downstream effectors of H4K20me | Coordinate repair pathway choice |
| Cell cycle regulators | Couple SETD8 activity to mitotic entry | Ensure genomic stability during division |
How Is histone H4K20 monomethyltransferase activity Regulated?
The activity of histone H4K20 monomethyltransferase is regulated at multiple levels. SETD8 protein abundance is controlled by the CRL4(Cdt2) ubiquitin ligase, which binds PCNA and DNA to target SETD8 for degradation in a cell cycle-dependent manner. This regulation ensures that H4K20 monomethylation is temporally restricted to appropriate phases of the cell cycle. Additionally, SETD8 activity is coupled to mitotic entry, and its catalytic function is required for genomic stability. The enzyme also establishes a repressive trans-tail histone code that regulates differentiation, indicating that its activity is integrated with developmental signaling. Furthermore, the monomethyl mark serves as a substrate for SUV420H1 and SUV420H2, which convert it to di- and trimethylated forms; this sequential regulation is critical for 53BP1 recruitment and NHEJ-directed repair. Finally, SETD8 can methylate non-histone substrates such as YAP, and this activity is subject to regulation by upstream signals that control colorectal cancer suppression.
histone H4K20 monomethyltransferase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SETD8 | Colorectal cancer suppression via YAP methylation | Knockout and point-mutation cell lines; xenograft models |
| SETD8 | Genomic instability and mitotic defects | CRISPR knockout in HeLa or HCT116 cells; live-cell imaging |
| SUV420H1/2 | DNA repair deficiency and 53BP1 recruitment defects | Knockout and knock-in models; DNA damage assays |
| SETD8 | Herpes simplex virus infection | Knockout cells infected with HSV-1; chromatin accessibility assays |
| PR-Set7 (Drosophila) | Differentiation defects | Drosophila mutants; developmental assays |
Cancer
Dysregulation of histone H4K20 monomethyltransferase activity has been implicated in cancer. SETD8-mediated monomethylation of YAP at K76 promotes K48-linked polyubiquitination and degradation of YAP, thereby suppressing colorectal cancer. Loss of SETD8 function leads to genomic instability, a hallmark of cancer, due to defective mitotic entry and DNA damage repair. The H4K20me mark is also required for 53BP1 recruitment and NHEJ, and defects in this pathway contribute to tumorigenesis. Therefore, targeting GO:0140944 may offer therapeutic opportunities in cancers with altered H4K20 methylation.
Genomic instability and DNA repair disorders
Insufficient H4K20 monomethylation causes mitotic defects and accumulation of DNA damage, leading to genomic instability. The concerted activities of SETD8 and SUV420H enzymes at DNA double-strand breaks are required for 53BP1 nucleation and NHEJ-directed repair; disruption of this cascade impairs DNA repair and sensitizes cells to DNA-damaging agents. Replication licensing is also dependent on SETD8 function through Suv4-20h, and its loss leads to replication stress. These findings link GO:0140944 to disorders characterized by genome instability.
Viral infection
SETD8, the enzyme responsible for GO:0140944, promotes global accessibility of infecting herpes simplex virus genomes. This suggests that H4K20 monomethylation plays a role in viral chromatin regulation and may influence viral replication and latency. Modulating this activity could therefore impact host-virus interactions.
Developmental and differentiation disorders
PR-Set7 establishes a repressive trans-tail histone code that regulates differentiation, and its activity is essential for normal development. Disruption of H4K20 monomethylation may therefore contribute to developmental abnormalities through altered gene expression programs. The dependence of replication licensing on PR-Set7 and Suv4-20h further underscores its importance in proliferative tissues.
From histone H4K20 monomethyltransferase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of SETD8 catalytic activity cause mitotic defects? | CRISPR knockout of SETD8 in human cell lines; live-cell imaging |
| Is H4K20 monomethylation required for 53BP1 recruitment? | Point mutation of SETD8 catalytic residue; DNA damage foci assays |
| Does SETD8-mediated YAP methylation suppress colorectal cancer? | Knock-in of methylation-deficient YAP mutant; xenograft models |
| How does SETD8 regulate replication licensing? | Knockout of SETD8 and Suv4-20h; replication assays |
| Does SETD8 promote HSV-1 genome accessibility? | Knockout cells infected with HSV-1; ATAC-seq |
| How is SETD8 abundance regulated by CRL4(Cdt2)? | Overexpression of Cdt2 and PCNA mutants; degradation assays |
How to Study the histone H4K20 monomethyltransferase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| ChIP-seq | Genomic distribution of H4K20me and SETD8 binding | Mapping chromatin marks and enzyme occupancy |
| Mass spectrometry | Histone and non-histone methylation | Detecting H4K20me and YAP methylation |
| Comet assay | DNA damage levels | Assessing genomic instability after SETD8 loss |
| 53BP1 foci assay | Recruitment of 53BP1 to double-strand breaks | Evaluating NHEJ repair efficiency |
| Live-cell imaging | Mitotic progression and chromosome segregation | Studying mitotic defects in knockout cells |
| Flow cytometry | Cell cycle distribution | Analyzing cell cycle arrest after SETD8 perturbation |
| ATAC-seq | Chromatin accessibility | Measuring HSV-1 genome accessibility |
| Ubiquitination assays | SETD8 degradation and YAP ubiquitination | Studying CRL4(Cdt2) regulation and YAP stability |
Chromatin immunoprecipitation and sequencing (ChIP-seq)
ChIP-seq using antibodies against H4K20me or epitope-tagged SETD8 can map the genomic distribution of the monomethyl mark and the enzyme's binding sites. This method is essential for understanding how GO:0140944 contributes to chromatin organization and gene regulation.
Mass spectrometry-based proteomics
Mass spectrometry can detect and quantify histone H4K20 monomethylation on histones and identify non-histone substrates such as YAP. This approach provides unbiased evidence for the catalytic activity of SETD8 and its downstream effects.
DNA damage and repair assays
Comet assays, gamma-H2AX foci, and 53BP1 recruitment assays are used to measure the functional consequences of H4K20 monomethylation on DNA repair. These methods link GO:0140944 to genome stability.
Live-cell imaging and cell cycle analysis
Fluorescence microscopy and flow cytometry can assess mitotic entry, chromosome segregation, and cell cycle progression in cells with altered SETD8 activity. These techniques are critical for understanding the role of GO:0140944 in mitosis.
How CRISPR Can Be Used to Study GO:0140944 histone H4K20 monomethyltransferase activity
Knockout
CRISPR knockout of SETD8 or SUV420H genes is used to abolish histone H4K20 monomethyltransferase activity and study its loss-of-function phenotypes, including mitotic defects, genomic instability, and impaired DNA repair. Knockout models are also valuable for assessing the role of H4K20me in viral infection and replication licensing.
Point Mutation
Point mutations in the catalytic SET domain of SETD8 can specifically inactivate the methyltransferase activity without affecting protein stability, allowing researchers to distinguish catalytic from scaffolding functions. Such models are crucial for demonstrating that the enzymatic activity of GO:0140944 is required for mitotic entry and 53BP1 recruitment.
Knock-in
Knock-in of epitope-tagged SETD8 or histone H4 mutants (e.g., H4K20R) enables precise tracking of the enzyme and substrate in live cells. Knock-in models also allow the study of methylation-deficient YAP mutants to dissect non-histone substrate functions.
Overexpression
Overexpression of wild-type or mutant SETD8 can be used to assess gain-of-function effects on chromatin structure, cell cycle progression, and cancer phenotypes. Overexpression models are particularly useful for studying the sufficiency of H4K20 monomethylation in driving specific biological outcomes.
How EDITGENE Supports histone H4K20 monomethyltransferase activity Research
Researchers studying histone H4K20 monomethyltransferase activity-related genes often need to determine whether a candidate gene is causally involved in a specific phenotype, such as mitotic defects, DNA repair deficiency, or cancer suppression. EDITGENE provides a comprehensive suite of CRISPR-based services to generate precisely engineered cell models that enable such causal inferences.
Contact EDITGENE today to design your custom CRISPR model for histone H4K20 monomethyltransferase activity research.
Frequently Asked Questions About histone H4K20 monomethyltransferase activity
What is histone H4K20 monomethyltransferase activity?
It is the enzymatic activity defined by GO:0140944 that adds a single methyl group to lysine 20 of histone H4, producing H4K20me and S-adenosyl-L-homocysteine.
What genes are involved in histone H4K20 monomethyltransferase activity?
The principal gene is SETD8 (also known as PR-Set7 or KMT5A), which encodes the enzyme responsible for this activity.
What is the role of SETD8 in histone H4K20 monomethylation?
SETD8 catalyzes the transfer of a methyl group from S-adenosyl-L-methionine to histone H4 lysine 20, and its catalytic function is essential for mitotic entry and genomic stability.
How is histone H4K20 monomethylation linked to DNA damage repair?
H4K20me is a prerequisite for subsequent di- and trimethylation by SUV420H enzymes, which recruit 53BP1 to DNA double-strand breaks and promote NHEJ-directed repair.
What diseases are associated with histone H4K20 monomethyltransferase activity?
Dysregulation is linked to cancer, genomic instability, and viral infection, including colorectal cancer suppression via YAP methylation and herpes simplex virus genome regulation.
What are the synonyms for GO:0140944?
Synonyms include histone H4K20 methylase activity, histone H4-K20 methylation, histone H4K20 methylation, histone H4K20 monomethylation, and histone lysine N-monomethyltransferase activity (H4-K20 specific).
How can I study histone H4K20 monomethyltransferase activity in the lab?
Common methods include ChIP-seq, mass spectrometry, DNA damage assays, live-cell imaging, and CRISPR-based knockout or point-mutation models.
What is the difference between H4K20me, H4K20me2, and H4K20me3?
H4K20me is the monomethylated form produced by GO:0140944, while H4K20me2 and H4K20me3 are generated by SUV420H enzymes and have distinct roles in DNA repair and chromatin compaction.
Is SETD8 the only enzyme with histone H4K20 monomethyltransferase activity?
SETD8 is the principal enzyme, but other proteins may contribute to H4K20 monomethylation in specific contexts; however, SETD8 is the best-characterized and essential for the reaction.
How does CRL4(Cdt2) regulate histone H4K20 monomethyltransferase activity?
CRL4(Cdt2) ubiquitin ligase binds PCNA and DNA to target SETD8 for degradation, thereby controlling the timing and abundance of H4K20 monomethylation during the cell cycle.
Conclusion
Histone H4K20 monomethyltransferase activity (GO:0140944) is a fundamental epigenetic modification catalyzed primarily by SETD8, with critical roles in mitotic entry, genomic stability, DNA damage repair, and replication licensing. Its dysregulation is linked to cancer, genomic instability, and viral infection, making it an important target for basic and translational research. CRISPR-based models, including knockout, point-mutation, knock-in, and overexpression, provide powerful tools to dissect the causal roles of this activity in health and disease. Continued investigation of GO:0140944 will likely yield new insights into chromatin biology and therapeutic opportunities.
References
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- 2. Houston SI et al.. 2008. Catalytic function of the PR-Set7 histone H4 lysine 20 monomethyltransferase is essential for mitotic entry and genomic stability.. J Biol Chem 283(28):19478-88 PMID: 18480059
- 3. Yu Y et al.. 2026. SETD8-mediated mono-methylation of YAP at K76 promotes K48-linked polyubiquitination and degradation to suppress colorectal cancer.. Cell Death Differ PMID: 42527521
- 4. Xu L et al.. 2022. Roles for the methyltransferase SETD8 in DNA damage repair.. Clin Epigenetics 14(1):34 PMID: 35246238
- 5. Mazian MA et al.. 2022. CRL4(Cdt2) Ubiquitin Ligase, A Genome Caretaker Controlled by Cdt2 Binding to PCNA and DNA.. Genes (Basel) 13(2) PMID: 35205311
- 6. Tuzon CT et al.. 2014. Concerted activities of distinct H4K20 methyltransferases at DNA double-strand breaks regulate 53BP1 nucleation and NHEJ-directed repair.. Cell Rep 8(2):430-8 PMID: 25001286
- 7. Sims JK et al.. 2008. PR-Set7 establishes a repressive trans-tail histone code that regulates differentiation.. Mol Cell Biol 28(14):4459-68 PMID: 18474616
- 8. Beck DB et al.. 2012. The role of PR-Set7 in replication licensing depends on Suv4-20h.. Genes Dev 26(23):2580-9 PMID: 23152447
