GO:0010485 histone H4 acetyltransferase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0010485 (histone H4 acetyltransferase activity) describes the enzymatic transfer of an acetyl group from acetyl-CoA to histone H4, a core chromatin modification.
• The activity is carried out by multi-subunit complexes such as Hat1-Hat2, NuA4, HBO1, and KAT8, which acetylate specific lysine residues on H4.
• Histone H4 acetylation is linked to transcription, DNA damage checkpoint signaling, and dosage compensation.
• Dysregulation of H4 acetyltransferase activity has been observed in cancers such as hepatomas and is implicated in developmental disorders.
• Key experimental approaches include knockout, point-mutation, knock-in, and overexpression models, combined with acetyltransferase assays, ChIP-seq, and proteomics.
• EDITGENE provides CRISPR-based services to dissect the causal roles of H4 acetyltransferase genes in disease and development.
Description
Histone H4 acetyltransferase activity (GO:0010485) is a molecular function that catalyzes the transfer of an acetyl group from acetyl-CoA to histone H4, forming acetyl-histone H4 and CoA. This modification neutralizes the positive charge of lysine residues, altering chromatin structure and creating docking sites for bromodomain-containing proteins, thereby influencing gene expression, DNA repair, and replication. The activity is essential for numerous cellular processes, and its dysregulation is associated with cancer and other diseases. Understanding the enzymes that carry out this reaction, their regulation, and their downstream effects is a major focus of epigenetic research.
histone H4 acetyltransferase activity At A Glance
| GO ID | GO:0010485 |
|---|---|
| GO term | histone H4 acetyltransferase activity |
| Ontology | molecular_function |
| Synonym | H4 histone acetylase activity; H4 histone acetyltransferase activity |
| Definition | Catalysis of the reaction: acetyl-CoA + histone H4 = CoA + acetyl-histone H4. |
| Major function | Acetylation of histone H4 lysine residues, influencing chromatin structure and gene regulation. |
| Representative complexes | Hat1-Hat2, NuA4, HBO1, KAT8 (MOF) |
| Associated processes | Transcription, DNA damage response, dosage compensation |
| Disease relevance | Cancer (e.g., hepatomas), developmental disorders |
What Is GO:0010485?
In simple terms, histone H4 acetyltransferase activity is the ability of an enzyme to attach an acetyl chemical tag onto histone H4 proteins. According to the QuickGO definition, it is the catalysis of the reaction: acetyl-CoA + histone H4 = CoA + acetyl-histone H4. This activity is a molecular function that modifies chromatin and is performed by dedicated histone acetyltransferase (HAT) enzymes, often within large multiprotein complexes.
Why Is histone H4 acetyltransferase activity Important in Cell Biology?
Histone H4 acetyltransferase activity is a central epigenetic mechanism that controls chromatin accessibility and gene expression programs. It is required for proper transcriptional regulation, DNA repair, and cell cycle progression, and its malfunction contributes to oncogenesis and other pathologies. Studying this activity helps researchers understand how cells maintain homeostasis and how to target epigenetic enzymes therapeutically.
• Regulates chromatin structure and gene transcription by neutralizing histone charges.
• Essential for DNA damage checkpoint signaling and genome stability.
• Plays a role in dosage compensation and resistance to fungal toxins in yeast.
• Involved in cellular homeostasis and transcription regulation by KAT8.
• Dysregulated in cancers such as rat hepatomas.
• Provides a target for epigenetic therapies in oncology.
• Serves as a model for studying enzyme complex assembly and substrate specificity.
• Enables research on histone code and bromodomain reader proteins.
• Critical for understanding developmental processes and cell differentiation.
• Facilitates CRISPR-based functional genomics of epigenetic regulators.
What Happens During histone H4 acetyltransferase activity?
Substrate recognition and binding
In simple terms: The enzyme first grabs onto the histone H4 protein and the acetyl-CoA molecule.
Histone H4 acetyltransferase enzymes recognize specific lysine residues on the H4 tail, often in the context of nucleosomes. For example, the Hat1-Hat2 complex binds to the H3-H4 tetramer, positioning the H4 tail for acetylation. The HBO1 complex, guided by JADE subunits, targets distinct lysine residues on H4. This step ensures specificity and is regulated by complex composition.
Catalytic transfer of acetyl group
In simple terms: The enzyme transfers an acetyl group from acetyl-CoA onto a lysine on histone H4.
The catalytic mechanism involves a conserved glutamate or other general base that deprotonates the lysine, facilitating nucleophilic attack on the acetyl-CoA thioester. This results in the formation of acetyl-histone H4 and CoA. The reaction is highly specific for H4 lysines such as K5, K8, K12, and K16, depending on the enzyme complex.
Chromatin remodeling and downstream signaling
In simple terms: The acetyl tag loosens chromatin and recruits other proteins that read the mark.
Acetylation of H4 neutralizes positive charges, weakening histone-DNA interactions and increasing chromatin accessibility. This facilitates transcription factor binding and recruitment of bromodomain-containing proteins. Additionally, H4 acetylation is required for DNA damage checkpoint signaling, as shown for Nat4 in yeast, and for dosage compensation on monosomic chromosomes.
Complex assembly and regulation
In simple terms: The enzyme works as part of a larger machine that can be turned on or off.
Histone H4 acetyltransferases function within multi-subunit complexes such as NuA4, HBO1, and KAT8, where accessory subunits dictate substrate specificity and activity. For instance, KAT8's acetyltransferase activity is complex-dependent and determines its role in transcription and cellular homeostasis. The Hat1-Hat2 complex requires Hat2 for optimal activity on H4.
Key Genes Involved in GO:0010485 histone H4 acetyltransferase activity
The following genes encode enzymes, subunits, or regulators directly associated with histone H4 acetyltransferase activity (GO:0010485).
| Gene | Major Role | Research Relevance |
|---|---|---|
| HAT1 | Catalytic subunit of Hat1-Hat2 complex; acetylates H4 K5, K12 | Histone deposition, DNA repair |
| HAT2 | Accessory subunit of Hat1 complex; enhances H4 acetylation | Complex assembly, substrate specificity |
| KAT8 (MOF) | Catalytic subunit of KAT8 complex; acetylates H4 K16 | Transcription, homeostasis, cancer |
| KAT5 (TIP60) | Catalytic subunit of NuA4 complex; acetylates H4 | DNA damage response, transcription |
| EP400 | Scaffold subunit of NuA4; required for H4 acetylation | Dosage compensation, chromatin remodeling |
| JADE1 | Subunit of HBO1 complex; guides H4 acetylation | Gene regulation, development |
| JADE2 | Subunit of HBO1 complex; modulates H4 acetylation | Transcription, cell proliferation |
| JADE3 | Subunit of HBO1 complex; targets H4 | Chromatin structure, cancer |
| HBO1 (KAT7) | Catalytic subunit of HBO1 complex; acetylates H4 | Replication, transcription |
| NAT4 | N-terminal acetyltransferase; acetylates H4 N-terminus | DNA damage checkpoint, stress response |
| GCN5 (KAT2A) | Histone acetyltransferase; can acetylate H4 in some contexts | Transcription, development |
| PCAF (KAT2B) | Histone acetyltransferase; H4 acetylation | Cell cycle, differentiation |
| CBP (CREBBP) | Histone acetyltransferase; H4 acetylation | Transcription, cancer |
| P300 (EP300) | Histone acetyltransferase; H4 acetylation | Transcription, cancer |
| ESA1 | Yeast catalytic subunit of NuA4; acetylates H4 | Dosage compensation, DNA repair |
| YNG2 | Yeast NuA4 subunit; required for H4 acetylation | Chromatin function |
| ARO1 | Yeast Hat1-Hat2 complex subunit | Histone deposition |
| HIF1 | Yeast Hat1-Hat2 complex subunit | Histone acetylation |
How Is histone H4 acetyltransferase activity Regulated?
Histone H4 acetyltransferase activity is regulated at multiple levels. Complex composition dictates substrate specificity and catalytic efficiency; for example, KAT8 activity depends on its associated subunits, and JADE subunits guide HBO1 to specific H4 lysines. Post-translational modifications of the enzymes themselves, such as phosphorylation or acetylation, can modulate their activity. Additionally, cellular signals like DNA damage can activate checkpoint kinases that influence H4 acetylation by Nat4. The availability of acetyl-CoA and the presence of inhibitor proteins also contribute to regulation.
histone H4 acetyltransferase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| KAT8 | Cancer, transcriptional dysregulation | Knockout and point-mutation cell lines; xenograft models |
| HAT1 | Histone deposition defects, DNA repair | Knockout in cancer cell lines; ChIP-seq |
| NAT4 | DNA damage checkpoint defects | Yeast knockout and point mutants; survival assays |
| JADE1 | Developmental disorders, cancer | Knockout and overexpression in mammalian cells |
| EP400 | Dosage compensation defects | Yeast knockout; H4 acetylation assays |
Cancer
Altered histone H4 acetyltransferase activity is observed in various cancers. In rat hepatomas, histone acetyltransferase activity was found to be elevated compared to normal liver, suggesting a role in tumorigenesis. KAT8, which acetylates H4 K16, is critical for transcription and cellular homeostasis, and its dysregulation can promote oncogenic gene expression programs. Targeting H4 acetyltransferases is being explored as a therapeutic strategy in oncology.
Developmental disorders
Proper H4 acetylation is essential for developmental gene regulation. Mutations in components of the HBO1 complex, such as JADE subunits, can disrupt H4 acetylation patterns and lead to developmental abnormalities. The NuA4 complex, which acetylates H4, is required for dosage compensation and proper gene expression during development.
DNA damage and genome instability
Histone H4 acetylation is required for DNA damage checkpoint signaling. In yeast, Nat4 acetylates H4 to regulate checkpoint activation, and its loss leads to sensitivity to DNA-damaging agents. This links H4 acetyltransferase activity to genome stability and cancer predisposition.
From histone H4 acetyltransferase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of HAT1 affect H4 acetylation and DNA repair? | HAT1 knockout cell line |
| How does KAT8 catalytic activity contribute to transcription? | KAT8 point-mutation (catalytic dead) knock-in |
| What is the role of Nat4 in DNA damage checkpoint? | NAT4 knockout yeast and point mutants |
| Can JADE1 overexpression alter H4 acetylation patterns? | JADE1 overexpression cell line |
| Does NuA4 complex require EP400 for H4 acetylation? | EP400 knockout yeast |
| Is HBO1 catalytic activity essential for cell proliferation? | HBO1 knockout and rescue with catalytic mutant |
How to Study the histone H4 acetyltransferase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| In vitro HAT assay | Enzymatic transfer of acetyl group to H4 | Comparing wild-type and mutant enzyme activity |
| ChIP-qPCR/seq | Genomic localization of H4 acetylation | Mapping changes upon knockout or overexpression |
| Mass spectrometry | Acetylation site identification and quantification | Determining substrate specificity |
| Western blot | Levels of acetylated H4 | Validating knockout or inhibitor effects |
| CRISPR knockout screen | Gene essentiality and pathway interactions | Identifying synthetic lethal partners |
| Co-immunoprecipitation | Protein-protein interactions in HAT complexes | Defining complex composition |
| RNA-seq | Transcriptional changes | Linking H4 acetylation to gene expression |
| Immunofluorescence | Nuclear localization of HATs and H4 acetylation | Visualizing chromatin changes |
Histone acetyltransferase assays
In vitro HAT assays using recombinant enzymes and histone H4 substrates, combined with radioactive or fluorescent acetyl-CoA, measure catalytic activity directly. These assays can be used to compare wild-type and mutant enzymes, such as KAT8 or Hat1.
Chromatin immunoprecipitation (ChIP)
ChIP with antibodies against acetylated H4 lysines (e.g., H4K5ac, H4K12ac, H4K16ac) followed by qPCR or sequencing maps the genomic distribution of H4 acetylation. This reveals how loss of enzymes like Hat1 or KAT8 affects chromatin marks.
Mass spectrometry-based proteomics
Quantitative mass spectrometry can identify and quantify acetylation sites on histone H4 across the genome. This approach is useful for studying the specificity of different HAT complexes and the impact of mutations.
CRISPR screens and functional genomics
Pooled CRISPR knockout screens targeting HAT genes can uncover their roles in cell fitness, drug resistance, and gene expression. Such screens have been used to study KAT8 and HBO1 complexes.
How CRISPR Can Be Used to Study GO:0010485 histone H4 acetyltransferase activity
Knockout
CRISPR knockout of HAT genes such as HAT1, KAT8, or HBO1 eliminates the enzyme, allowing researchers to assess loss of H4 acetylation and downstream phenotypes. For example, KAT8 knockout reduces H4K16ac and alters transcription. Knockout of HAT1 affects histone deposition and DNA repair.
Point Mutation
Introducing catalytic-dead point mutations (e.g., in the acetyl-CoA binding site) via CRISPR knock-in distinguishes enzymatic activity from scaffolding functions. This has been used for KAT8 to show that its acetyltransferase activity is complex-dependent. Point mutants of Nat4 reveal its role in DNA damage checkpoint.
Knock-in
Knock-in of tagged versions (e.g., FLAG, HA) of HAT enzymes enables affinity purification of complexes and ChIP analysis. Tagged Hat1 and HBO1 have been used to study complex composition and genomic binding.
Overexpression
CRISPR activation or cDNA overexpression of HAT genes can increase H4 acetylation and drive specific transcriptional programs. Overexpression of JADE1, for instance, alters H4 acetylation and cell proliferation. This approach helps identify gain-of-function effects in cancer.
How EDITGENE Supports histone H4 acetyltransferase activity Research
Researchers studying histone H4 acetyltransferase activity-related genes often need to determine whether a candidate gene is causally involved in a specific biological process or disease. EDITGENE provides a comprehensive suite of CRISPR-based services to enable precise genetic manipulation and functional interrogation of these epigenetic regulators.
Contact EDITGENE today to design your custom CRISPR model for histone H4 acetyltransferase activity research.
Frequently Asked Questions About histone H4 acetyltransferase activity
What is histone H4 acetyltransferase activity?
It is the enzymatic activity that transfers an acetyl group from acetyl-CoA to histone H4, as defined by GO:0010485.
What genes are involved in histone H4 acetyltransferase activity?
Key genes include HAT1, HAT2, KAT8, KAT5, EP400, JADE1/2/3, HBO1, and NAT4, among others.
Which complexes carry out histone H4 acetylation?
Major complexes include Hat1-Hat2, NuA4, HBO1, and KAT8.
What diseases are linked to histone H4 acetyltransferase activity?
Cancer, developmental disorders, and genome instability have been associated with dysregulation of this activity.
How can I study histone H4 acetyltransferase activity in the lab?
Common methods include in vitro HAT assays, ChIP-seq, mass spectrometry, and CRISPR knockout models.
What is the role of KAT8 in H4 acetylation?
KAT8 acetylates H4 K16, and its activity is complex-dependent, influencing transcription and cellular homeostasis.
How does Hat1 acetylate histone H4?
Hat1, in complex with Hat2, acetylates H4 at lysines 5 and 12, important for histone deposition and DNA repair.
Is histone H4 acetyltransferase activity involved in DNA damage response?
Yes, Nat4 acetylates H4 to regulate DNA damage checkpoint signaling in yeast.
Can CRISPR be used to study H4 acetyltransferase genes?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression are widely used to dissect gene function.
What are the synonyms for GO:0010485?
The synonyms are H4 histone acetylase activity and H4 histone acetyltransferase activity.
Conclusion
Histone H4 acetyltransferase activity (GO:0010485) is a fundamental epigenetic function that regulates chromatin structure and gene expression. Its dysregulation is implicated in cancer and other diseases, making it a key target for research. By leveraging CRISPR-based models and advanced analytical methods, researchers can uncover the precise roles of H4 acetyltransferases and their complexes. EDITGENE provides the tools and expertise to accelerate these discoveries.
References
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- 2. Constantinou M et al.. 2024. Yeast Nat4 regulates DNA damage checkpoint signaling through its N-terminal acetyltransferase activity on histone H4.. PLoS Genet 20(10):e1011433 PMID: 39356727
- 3. Radzisheuskaya A et al.. 2021. Complex-dependent histone acetyltransferase activity of KAT8 determines its role in transcription and cellular homeostasis.. Mol Cell 81(8):1749-1765.e8 PMID: 33657400
- 4. Grant PA et al.. 1999. Histone acetyltransferase complexes.. Semin Cell Dev Biol 10(2):169-77 PMID: 10441070
- 5. Wakabayashi H et al.. 2017. NuA4 histone acetyltransferase activity is required for H4 acetylation on a dosage-compensated monosomic chromosome that confers resistance to fungal toxins.. Epigenetics Chromatin 10(1):49 PMID: 29061172
- 6. Parthun MR. 2012. Histone acetyltransferase 1: more than just an enzyme?. Biochim Biophys Acta 1819(3-4):256-63 PMID: 24459728
- 7. Gaurav N et al.. 2024. Guiding the HBO1 complex function through the JADE subunit.. Nat Struct Mol Biol 31(7):1039-1049 PMID: 38448574
- 8. Grunicke HH et al.. 1989. Histone acetyltransferase activity in rat hepatomas.. J Cancer Res Clin Oncol 115(5):435-8 PMID: 2808481
