GO:0043999 histone H2AK5 acetyltransferase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0043999 describes the enzymatic activity that transfers an acetyl group from acetyl-CoA to lysine 5 of histone H2A, producing N6-acetyl-L-lysine at that position.
• The reaction is catalyzed by histone acetyltransferases such as Hat1, which acetylates H2A at lysine 5 in vivo.
• Tip60 is a histone acetyltransferase that can be recruited by UHRF1 and contributes to H2A acetylation, including at K5.
• Histone H2AK5 acetylation is associated with active chromatin and has been observed on Myc target genes.
• In model organisms, H2AK5 acetylation is linked to X chromosome crossover formation and genome stability, independently of xnd-1.
• Dysregulation of H2AK5 acetylation may contribute to diseases such as sepsis-associated encephalopathy through epigenetic control of microglial dynamics.
Description
Histone H2AK5 acetyltransferase activity (GO:0043999) is a molecular function that catalyzes the acetylation of histone H2A at lysine 5. This modification is part of the broader histone acetylation code that regulates chromatin structure and gene expression. The enzyme transfers an acetyl group from acetyl-CoA to the epsilon-amino group of lysine 5, neutralizing the positive charge of the histone and weakening its interaction with DNA, thereby promoting an open chromatin state. This activity is essential for various nuclear processes, including transcription, DNA repair, and chromosome segregation. Researchers study GO:0043999 to understand how specific histone modifications contribute to gene regulation and how their dysregulation leads to disease.
histone H2AK5 acetyltransferase activity At A Glance
| GO ID | GO:0043999 |
|---|---|
| GO term | histone H2AK5 acetyltransferase activity |
| Ontology | molecular_function |
| Synonym | histone acetylase activity (H2A-K5 specific); histone acetyltransferase activity (H2A-K5 specific); histone H2A-K5 acetyltransferase activity; histone lysine N-acetyltransferase activity (H2A-K5 specific) |
| Major function | Catalyzes the acetylation of histone H2A at lysine 5 using acetyl-CoA |
| Reaction | acetyl-CoA + histone H2A L-lysine (position 5) = CoA + histone H2A N6-acetyl-L-lysine (position 5) |
| Substrate | Histone H2A (lysine 5) and acetyl-CoA |
| Product | N6-acetyl-L-lysine at position 5 of histone H2A and CoA |
| Cofactor | Acetyl-CoA as acetyl group donor |
What Is GO:0043999?
GO:0043999 is defined as the catalysis of the reaction: acetyl-CoA + histone H2A L-lysine (position 5) = CoA + histone H2A N6-acetyl-L-lysine (position 5). In other words, it is the enzyme activity that specifically acetylates the fifth lysine residue of histone H2A, using acetyl-CoA as the acetyl donor. This activity is also known as histone H2A-K5 acetyltransferase activity or histone acetylase activity (H2A-K5 specific).
Why Is histone H2AK5 acetyltransferase activity Important in Cell Biology?
Histone H2AK5 acetyltransferase activity is important because it introduces a specific epigenetic mark that influences chromatin accessibility and gene expression programs. This activity is implicated in fundamental processes such as transcription activation, DNA damage response, and chromosome segregation. Its dysregulation has been linked to cancer, neurodevelopmental disorders, and immune-related diseases. Understanding GO:0043999 provides insights into how epigenetic enzymes contribute to normal development and disease pathogenesis, and it offers potential targets for therapeutic intervention.
• Regulates chromatin structure and gene expression by acetylating histone H2A at lysine 5.
• Plays a role in transcriptional activation of specific target genes, such as Myc targets.
• Involved in DNA repair and genome stability, as shown by studies in C. elegans.
• Contributes to X chromosome crossover formation during meiosis.
• Linked to immune and inflammatory responses through epigenetic control of microglial dynamics.
• Potential involvement in cancer, as histone acetylation is frequently altered in tumors.
• May serve as a biomarker for epigenetic dysregulation in disease.
• Target for epigenetic therapies aimed at modulating histone acetylation.
• Essential for understanding the histone code and its role in development.
• Provides a model for studying enzyme-substrate specificity in histone modification.
What Happens During histone H2AK5 acetyltransferase activity?
Substrate recognition and binding
In simple terms: The enzyme finds and grabs the histone protein and the acetyl group donor.
The acetyltransferase enzyme recognizes histone H2A, specifically the N-terminal tail containing lysine 5, and binds to it. It also binds acetyl-CoA, the acetyl group donor. This step ensures that the acetyl group is transferred to the correct lysine residue.
Catalytic transfer of acetyl group
In simple terms: The enzyme moves the acetyl group from acetyl-CoA onto the lysine.
The enzyme catalyzes the transfer of the acetyl group from acetyl-CoA to the epsilon-amino group of lysine 5 on histone H2A. This results in the formation of N6-acetyl-L-lysine at position 5 and the release of coenzyme A. The reaction neutralizes the positive charge of the lysine, weakening histone-DNA interactions.
Chromatin remodeling and downstream effects
In simple terms: The modified histone changes how DNA is packaged, affecting gene activity.
Acetylation of H2AK5 leads to a more open chromatin conformation, facilitating access for transcription factors and other regulatory proteins. This modification is associated with active transcription and is observed on target genes such as those regulated by Myc. It also plays roles in DNA repair and chromosome segregation.
Regulation by interacting proteins
In simple terms: Other proteins can turn the enzyme on or off or bring it to the right place.
The activity of H2AK5 acetyltransferases can be regulated by interacting proteins. For example, UHRF1 recruits the histone acetyltransferase Tip60 and controls its expression and activity, thereby influencing H2A acetylation. This regulation ensures that acetylation occurs at the right time and place.
Key Genes Involved in GO:0043999 histone H2AK5 acetyltransferase activity
The following genes and proteins are directly involved in or regulate histone H2AK5 acetyltransferase activity, as supported by published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| HAT1 | Histone acetyltransferase that acetylates H2AK5 in vivo | Key enzyme for H2AK5 acetylation; knockout studies reveal its role in chromatin assembly and DNA repair |
| KAT5 (Tip60) | Histone acetyltransferase recruited by UHRF1; can acetylate H2A | Involved in DNA damage response and transcriptional regulation; its recruitment affects H2A acetylation |
| UHRF1 | Recruits Tip60 and controls its expression and activity | Epigenetic regulator that links DNA methylation and histone acetylation |
| MYC | Transcription factor that induces histone modifications on target chromatin | Drives H2AK5 acetylation on target genes; model for studying oncogenic transcription |
| XND-1 | Regulates X chromosome crossover formation and genome stability independently of H2AK5 acetylation | Provides insights into meiotic processes and genome stability |
| NME2 | Drives epigenetic control of inflammasome-activated microglial lineage dynamics | Links H2AK5 acetylation to neuroinflammation in sepsis-associated encephalopathy |
| H2AFX | Histone H2A variant; can be acetylated at K5 | Involved in DNA damage signaling; potential substrate for H2AK5 acetyltransferases |
| H2AFZ | Histone H2A variant; potential substrate | Replacement histone variant; may be acetylated at K5 in specific contexts |
| EP300 | Histone acetyltransferase that can acetylate H2A | Broad-spectrum HAT; may contribute to H2AK5 acetylation in some contexts |
| CREBBP | Histone acetyltransferase with broad specificity | Potential H2AK5 acetyltransferase; involved in transcriptional coactivation |
| KAT2A (GCN5) | Histone acetyltransferase that can modify H2A | Part of SAGA complex; may acetylate H2AK5 |
| KAT2B (PCAF) | Histone acetyltransferase | Potential H2AK5 acetyltransferase; involved in cell cycle and differentiation |
| HDAC1 | Histone deacetylase that removes acetyl groups | Counteracts H2AK5 acetylation; regulates chromatin state |
| HDAC2 | Histone deacetylase | Opposes H2AK5 acetylation; target for epigenetic drugs |
| SIRT1 | NAD+-dependent deacetylase | May deacetylate H2AK5; links metabolism to chromatin |
| BRD4 | Bromodomain protein that binds acetylated histones | Reader of H2AK5 acetylation; involved in transcription elongation |
| ING4 | Inhibitor of growth family member; component of HAT complexes | May modulate H2AK5 acetylation through complex assembly |
| JADE1 | Component of HBO1 complex | Potential regulator of H2AK5 acetylation |
How Is histone H2AK5 acetyltransferase activity Regulated?
Histone H2AK5 acetyltransferase activity is regulated at multiple levels. The expression and activity of the enzymes themselves, such as Tip60, are controlled by interacting proteins like UHRF1. Additionally, the recruitment of these enzymes to specific chromatin regions is guided by transcription factors and other chromatin modifiers. Post-translational modifications of the acetyltransferases and their association with cofactors can also modulate their activity. Furthermore, the reverse reaction catalyzed by histone deacetylases (HDACs) ensures a dynamic balance of acetylation.
histone H2AK5 acetyltransferase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| HAT1 | Cancer, chromatin assembly disorders | HAT1 knockout cell lines; xenograft models |
| KAT5 (Tip60) | Cancer, DNA repair deficiencies | Tip60 conditional knockout mice; patient-derived organoids |
| MYC | Burkitt lymphoma, neuroblastoma | Myc-driven transgenic models; CRISPR knock-in of acetylation-deficient H2A |
| NME2 | Sepsis-associated encephalopathy | NME2 knockout microglia; LPS-induced sepsis models |
| XND-1 | Meiotic defects, genome instability | C. elegans xnd-1 mutants; CRISPR knockout |
Cancer
Altered histone acetylation, including H2AK5 acetylation, is a hallmark of many cancers. Overexpression or dysregulation of histone acetyltransferases like Tip60 and Hat1 can lead to aberrant gene expression that promotes tumorigenesis. For example, Myc-driven cancers often exhibit increased H2AK5 acetylation on target genes, contributing to oncogenic transcription programs.
Sepsis-associated encephalopathy
NME2-driven epigenetic control of microglial lineage dynamics involves H2AK5 acetylation and promotes sepsis-associated encephalopathy. Dysregulation of this pathway can lead to excessive inflammasome activation and neuroinflammation.
Genome instability disorders
Defects in H2AK5 acetylation can impair DNA repair and chromosome segregation, leading to genome instability. Studies in C. elegans show that xnd-1 regulates crossover formation and genome stability independently of H2AK5 acetylation, highlighting the importance of this modification in maintaining genomic integrity.
From histone H2AK5 acetyltransferase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of HAT1 reduce H2AK5 acetylation and affect chromatin assembly? | HAT1 knockout cell lines (CRISPR/Cas9) |
| How does Tip60 recruitment by UHRF1 regulate H2AK5 acetylation? | UHRF1 knockout or knockdown cells; rescue with wild-type or mutant UHRF1 |
| What is the role of H2AK5 acetylation in Myc-driven transcription? | Myc-inducible cell lines; H2A K5R point mutant knock-in |
| Does H2AK5 acetylation contribute to sepsis-associated encephalopathy? | NME2 knockout mice; microglia-specific deletion |
| How does H2AK5 acetylation affect X chromosome crossover? | C. elegans xnd-1 mutants; H2A K5R knock-in |
| Can HDAC inhibitors modulate H2AK5 acetylation levels? | Cell lines treated with HDAC inhibitors; H2AK5ac-specific antibodies |
How to Study the histone H2AK5 acetyltransferase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| ChIP-seq | Genome-wide distribution of H2AK5ac | Mapping acetylation at target genes |
| Mass spectrometry | Site-specific acetylation on histone H2A | Quantifying H2AK5ac in cells |
| Western blot | Global levels of H2AK5ac | Validating changes in acetylation |
| In vitro HAT assay | Enzymatic activity of H2AK5 acetyltransferases | Screening for inhibitors or activators |
| Immunofluorescence | Nuclear localization of H2AK5ac | Visualizing acetylation patterns |
| CRISPR screening | Identification of genes regulating H2AK5ac | Functional genomics |
| RNA-seq | Transcriptional changes upon modulation of H2AK5ac | Gene expression profiling |
| Proteomics | Global protein acetylation changes | Systems-level analysis |
Chromatin immunoprecipitation (ChIP)
ChIP with antibodies specific to H2AK5ac can map the genomic distribution of this modification. This method reveals which genes and regulatory regions are associated with H2AK5 acetylation under different conditions.
Mass spectrometry
Mass spectrometry-based proteomics can identify and quantify H2AK5 acetylation on histones isolated from cells or tissues. This approach provides site-specific information and can detect changes in response to perturbations.
Western blotting with modification-specific antibodies
Western blotting using antibodies that specifically recognize H2AK5ac allows semi-quantitative assessment of global acetylation levels. It is commonly used to validate changes seen in other assays.
Enzymatic assays
In vitro acetyltransferase assays using recombinant enzymes and histone substrates can directly measure H2AK5 acetyltransferase activity. These assays typically use radiolabeled acetyl-CoA or fluorescent substrates.
How CRISPR Can Be Used to Study GO:0043999 histone H2AK5 acetyltransferase activity
Knockout
CRISPR/Cas9-mediated knockout of genes encoding H2AK5 acetyltransferases (e.g., HAT1, KAT5) can abolish or reduce H2AK5 acetylation, allowing researchers to study its loss-of-function phenotypes in processes such as transcription, DNA repair, and development.
Point Mutation
Introducing point mutations in the histone H2A gene to change lysine 5 to arginine (K5R) prevents acetylation at this site. This knock-in strategy enables precise dissection of the functional significance of H2AK5 acetylation without affecting other histone modifications.
Knock-in
Knock-in of tagged or mutant versions of H2A or acetyltransferases can be used to track protein localization, interaction partners, or to express acetylation-mimicking (K5Q) or acetylation-deficient (K5R) histones. These models help link the modification to specific biological outcomes.
Overexpression
Overexpression of H2AK5 acetyltransferases or histone H2A can increase acetylation levels, providing gain-of-function models to study the consequences of hyperacetylation on chromatin structure and gene expression.
How EDITGENE Supports histone H2AK5 acetyltransferase activity Research
Researchers studying histone H2AK5 acetyltransferase activity-related genes often need to determine whether a candidate gene is causally involved in the modification and its downstream effects. EDITGENE provides a comprehensive suite of CRISPR-based services to facilitate these investigations, from gene knockout to precise point mutations and knock-ins, as well as library screening and bioinformatics support.
Contact EDITGENE today to design your custom CRISPR model for histone H2AK5 acetyltransferase activity research.
Frequently Asked Questions About histone H2AK5 acetyltransferase activity
What is histone H2AK5 acetyltransferase activity?
It is the enzyme activity that adds an acetyl group to lysine 5 of histone H2A, a modification that regulates chromatin structure and gene expression.
What genes are involved in histone H2AK5 acetyltransferase activity?
Key genes include HAT1, KAT5 (Tip60), and MYC, which encode or regulate enzymes that acetylate H2AK5.
What is the GO ID for histone H2AK5 acetyltransferase activity?
The Gene Ontology ID is GO:0043999.
How is histone H2AK5 acetylation detected?
It can be detected using modification-specific antibodies in Western blot, ChIP, or immunofluorescence, as well as by mass spectrometry.
What diseases are associated with histone H2AK5 acetylation?
Dysregulation has been linked to cancer, sepsis-associated encephalopathy, and genome instability disorders.
Which enzymes catalyze H2AK5 acetylation?
Histone acetyltransferases such as Hat1 and Tip60 can catalyze this reaction.
Is H2AK5 acetylation reversible?
Yes, it is reversed by histone deacetylases (HDACs), which remove the acetyl group.
What is the role of H2AK5 acetylation in transcription?
It is associated with active chromatin and promotes transcription of target genes, including Myc targets.
Can CRISPR be used to study H2AK5 acetylation?
Yes, CRISPR knockout, point mutation, and knock-in models are powerful tools to dissect the function of H2AK5 acetylation.
What model organisms are used to study H2AK5 acetylation?
Common models include human cell lines, mice, and Caenorhabditis elegans.
Conclusion
Histone H2AK5 acetyltransferase activity (GO:0043999) is a critical epigenetic modification that regulates chromatin dynamics and gene expression. Its involvement in cancer, neuroinflammation, and genome stability underscores its importance in human health. Continued research using advanced CRISPR models and multi-omics approaches will further elucidate its mechanistic roles and therapeutic potential.
References
- 1. Achour M et al.. 2009. UHRF1 recruits the histone acetyltransferase Tip60 and controls its expression and activity.. Biochem Biophys Res Commun 390(3):523-8 PMID: 19800870
- 2. Wu QR et al.. 2026. NME2-driven epigenetic control of inflammasome-activated microglial lineage dynamics promotes sepsis-associated encephalopathy.. Brain Behav Immun 135:106492 PMID: 41713665
- 3. Tafrova JI et al.. 2014. Human histone acetyltransferase 1 (Hat1) acetylates lysine 5 of histone H2A in vivo.. Mol Cell Biochem 392(1-2):259-72 PMID: 24682716
- 4. Martinato F et al.. 2008. Analysis of Myc-induced histone modifications on target chromatin.. PLoS One 3(11):e3650 PMID: 18985155
- 5. McClendon TB et al.. 2016. X Chromosome Crossover Formation and Genome Stability in Caenorhabditis elegans Are Independently Regulated by xnd-1.. G3 (Bethesda) 6(12):3913-3925 PMID: 27678523
