GO:1990244 histone H2AT120 kinase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:1990244 histone H2AT120 kinase activity is a molecular function that catalyzes phosphorylation of histone H2A at threonine 120 using ATP.
• The principal enzyme reported to carry this intrinsic kinase activity is VprBP/DCAF1, which phosphorylates H2AT120 and represses gene transcription.
• H2AT120 phosphorylation by VprBP/DCAF1 drives aberrant gene silencing in prostate cancer, colon cancer, and melanoma.
• TIP60-mediated acetylation of Bub1 regulates centromeric H2AT120 phosphorylation for faithful chromosome segregation.
• VprBP-dependent H2A phosphorylation also controls osteoclast differentiation, linking the modification to bone biology.
• Small-molecule kinase inhibitors such as OTSSP167 can abrogate mitotic checkpoint function by inhibiting multiple mitotic kinases, including those acting on H2A.
Description
GO:1990244 histone H2AT120 kinase activity is a molecular function defined as the catalysis of the reaction histone H2A-threonine (position 120) + ATP = histone H2A-phosphothreonine (position 120) + ADP. This activity adds a phosphate group to threonine 120 of histone H2A, a histone modification that has been linked to transcriptional repression and mitotic regulation. The term is distinct from other histone kinase activities because it specifies both the histone substrate (H2A) and the exact residue (T120).
histone H2AT120 kinase activity At A Glance
| GO ID | GO:1990244 |
|---|---|
| GO term | histone H2AT120 kinase activity |
| Ontology | molecular_function |
| Synonym | histone H2AS120 kinase activity; histone H2A-T120 kinase activity; histone kinase activity (H2A-T120 specific); histone threonine kinase activity (H2A-T120 specific) |
| Major function | Catalyzes phosphorylation of histone H2A at threonine 120 using ATP, producing ADP and H2A-phosphothreonine 120 |
| Reaction | histone H2A-threonine (position 120) + ATP = histone H2A-phosphothreonine (position 120) + ADP |
| Substrate | Histone H2A threonine 120 |
| Cofactor | ATP (required as phosphate donor) |
| Primary enzyme reported | VprBP/DCAF1 intrinsic kinase activity |
What Is GO:1990244?
In practical terms, GO:1990244 describes the enzymatic activity that transfers the gamma-phosphate of ATP onto threonine 120 of histone H2A. The reaction consumes ATP and produces ADP plus phosphorylated H2A at T120. This is a histone kinase activity with strict substrate and site specificity, and it is annotated as a molecular function rather than a biological process or cellular component.
Why Is histone H2AT120 kinase activity Important in Cell Biology?
Histone H2AT120 kinase activity is important because it directly couples ATP-dependent signaling to chromatin modification and gene silencing. VprBP/DCAF1-mediated H2AT120 phosphorylation represses transcription and contributes to tumorigenesis in prostate cancer, colon cancer, and melanoma. In addition, centromeric H2AT120 phosphorylation is regulated by TIP60 acetylation of Bub1 and is required for faithful chromosome segregation. The modification also participates in osteoclast differentiation, expanding its biological relevance beyond cancer.
• Provides a direct enzymatic link between ATP metabolism and chromatin-based transcriptional repression.
• Drives aberrant gene silencing in prostate tumorigenesis through VprBP kinase activity.
• Contributes to colon cancer pathogenesis via DCAF1/VprBP-dependent EZH2 stabilization and gene silencing.
• Mediates melanomagenic gene silencing through histone H2A phosphorylation.
• Regulates centromeric H2AT120 phosphorylation for faithful chromosome segregation via TIP60-Bub1 signaling.
• Controls osteoclast differentiation through an epigenetic mechanism involving histone H2A phosphorylation.
• Represents a potential target for kinase inhibitors such as OTSSP167 that affect mitotic checkpoint kinases.
• Serves as a mechanistic entry point for studying how histone kinases shape cancer epigenomes.
What Happens During histone H2AT120 kinase activity?
Substrate recognition and ATP binding
In simple terms: The enzyme first grabs ATP and the histone H2A protein so it can add a phosphate tag.
The kinase activity defined by GO:1990244 requires ATP as the phosphate donor and histone H2A threonine 120 as the acceptor. VprBP/DCAF1 has been shown to possess intrinsic kinase activity that targets histone H2A, establishing it as a key enzyme for this reaction.
Phosphoryl transfer to H2A T120
In simple terms: The phosphate group is moved from ATP onto threonine 120 of histone H2A.
During catalysis, the gamma-phosphate of ATP is transferred to the hydroxyl group of threonine 120 on histone H2A, yielding ADP and histone H2A-phosphothreonine 120. This reaction is the defining event of GO:1990244 and is mediated by VprBP/DCAF1 kinase activity.
Chromatin association and transcriptional repression
In simple terms: Once H2A is phosphorylated, it helps shut down nearby genes.
VprBP/DCAF1-mediated H2A phosphorylation represses gene transcription, and this activity is linked to tumorigenic gene silencing in prostate cancer and melanoma. The phosphorylation mark therefore acts as a chromatin modification that promotes a repressive transcriptional state.
Centromeric H2AT120 phosphorylation and mitotic regulation
In simple terms: At the centromere, this modification helps chromosomes separate correctly during cell division.
TIP60 acetylation of Bub1 regulates centromeric H2AT120 phosphorylation, which is required for faithful chromosome segregation. This connects GO:1990244 to mitotic checkpoint control and genome stability.
Physiological role in osteoclast differentiation
In simple terms: The same modification also helps immune-related bone cells mature.
VprBP regulates osteoclast differentiation via an epigenetic mechanism involving histone H2A phosphorylation, demonstrating that GO:1990244 is not limited to cancer biology.
Key Genes Involved in GO:1990244 histone H2AT120 kinase activity
The following genes and proteins are directly implicated in histone H2AT120 kinase activity or its regulation, based on the verified literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| VprBP/DCAF1 | Intrinsic kinase activity targeting histone H2A; represses transcription | Central enzyme for GO:1990244; drives tumorigenesis and gene silencing |
| H2A (histone H2A) | Substrate; threonine 120 is the phospho-acceptor | Defines the substrate specificity of the kinase activity |
| EZH2 | Polycomb repressive complex 2 subunit; stabilized by DCAF1/VprBP | Links H2A phosphorylation to aberrant gene silencing in colon cancer |
| Bub1 | Kinetochore protein; acetylation by TIP60 regulates centromeric H2AT120 phosphorylation | Connects GO:1990244 to chromosome segregation |
| TIP60 | Acetyltransferase that acetylates Bub1 | Regulates centromeric H2AT120 phosphorylation |
| OTSSP167 | Small-molecule kinase inhibitor | Abrogates mitotic checkpoint through inhibition of multiple mitotic kinases |
| VprBP (prostate cancer context) | Kinase activity drives prostate tumorigenesis | Direct evidence for GO:1990244 in prostate cancer |
| VprBP (melanoma context) | Triggers melanomagenic gene silencing via H2A phosphorylation | Supports role in melanoma |
| VprBP (osteoclast context) | Regulates osteoclast differentiation epigenetically | Extends function beyond cancer |
| DCAF1 | Alternative name for VprBP; part of CRL4 E3 ligase | Same protein as VprBP; kinase and scaffolding functions |
| H2A-phosphothreonine 120 | Modified histone mark | Readout of GO:1990244 activity |
| ATP | Phosphate donor | Required cofactor for the kinase reaction |
| ADP | Reaction product | Byproduct of phosphoryl transfer |
| Histone H2A T120 | Specific residue phosphorylated | Defines the site specificity of the activity |
| CRL4 complex | E3 ubiquitin ligase complex containing DCAF1/VprBP | Provides context for VprBP functions |
| PRC2 | Polycomb repressive complex 2 | Downstream effector of gene silencing linked to H2A phosphorylation |
How Is histone H2AT120 kinase activity Regulated?
The activity is regulated at multiple levels. TIP60-mediated acetylation of Bub1 controls centromeric H2AT120 phosphorylation, linking the modification to mitotic signaling. VprBP/DCAF1 itself is part of the CRL4 E3 ligase complex, and its kinase activity can be modulated in cancer contexts. Pharmacological inhibition of mitotic kinases by OTSSP167 affects mitotic checkpoint function, suggesting that H2AT120 kinase activity can be targeted indirectly.
histone H2AT120 kinase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| VprBP/DCAF1 | Prostate cancer | VprBP knockout or kinase-dead point mutant in prostate cancer cell lines |
| DCAF1/VprBP | Colon cancer | DCAF1 knockout or overexpression in colon cancer cells |
| VprBP/DCAF1 | Melanoma | VprBP knockdown or knockout in melanoma cell lines |
| Bub1/TIP60 | Chromosome segregation defects | Bub1 acetylation-site mutants or TIP60 knockout cells |
| VprBP | Osteoclast differentiation | VprBP conditional knockout in osteoclast precursor cells |
Prostate cancer
VprBP drives prostate tumorigenesis through its kinase activity targeting histone H2A, directly implicating GO:1990244 in prostate cancer pathogenesis.
Colon cancer
Phosphorylation and stabilization of EZH2 by DCAF1/VprBP trigger aberrant gene silencing in colon cancer, connecting H2A phosphorylation to epigenetic reprogramming.
Melanoma
VprBP/DCAF1 triggers melanomagenic gene silencing through histone H2A phosphorylation, supporting a role for GO:1990244 in melanoma.
Bone biology and osteoclast differentiation
VprBP regulates osteoclast differentiation via an epigenetic mechanism involving histone H2A phosphorylation, indicating relevance to bone homeostasis.
From histone H2AT120 kinase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does VprBP kinase activity directly phosphorylate H2AT120? | Kinase-dead point mutation of VprBP (e.g., catalytic residue mutation) |
| Is H2AT120 phosphorylation required for gene silencing? | H2A T120A or T120D knock-in cell lines |
| Does loss of VprBP affect tumor growth? | VprBP knockout in prostate cancer xenografts |
| How does TIP60 regulate centromeric H2AT120 phosphorylation? | TIP60 knockout or Bub1 acetylation-site mutant cells |
| Does VprBP regulate osteoclast differentiation? | VprBP conditional knockout mice or osteoclast precursors |
| Can kinase inhibitors block H2AT120 phosphorylation? | OTSSP167 treatment in mitotic cells |
How to Study the histone H2AT120 kinase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| In vitro kinase assay | Phosphorylation of H2A T120 by a candidate kinase | Validate VprBP/DCAF1 intrinsic kinase activity |
| Western blot with phospho-H2AT120 antibody | Levels of H2A T120 phosphorylation | Monitor changes after knockout or inhibitor treatment |
| ChIP-seq | Genomic localization of H2A phosphoT120 | Map repressive chromatin domains |
| RNA-seq | Transcriptional changes upon loss of H2AT120 kinase activity | Identify genes silenced by VprBP/DCAF1 |
| Immunofluorescence | Subcellular localization of H2A phosphoT120 | Study centromeric phosphorylation during mitosis |
| CRISPR knockout screening | Genes required for H2AT120 phosphorylation or related phenotypes | Discover regulators of the modification |
| Kinase inhibitor profiling | Sensitivity of mitotic kinases to inhibitors | Evaluate OTSSP167 effects on H2AT120 phosphorylation |
| Osteoclast differentiation assay | Formation of multinucleated osteoclasts | Test VprBP-dependent H2A phosphorylation in bone biology |
Kinase assays
In vitro kinase assays using recombinant VprBP/DCAF1 and histone H2A or H2A T120 peptides can directly measure GO:1990244 activity by detecting incorporation of radiolabeled or fluorescent phosphate.
Phospho-specific antibodies and immunoblotting
Antibodies against histone H2A-phosphothreonine 120 can be used in Western blotting and immunofluorescence to monitor the modification in cells and tissues.
Chromatin immunoprecipitation (ChIP)
ChIP with anti-H2A-phosphoT120 antibodies can map the genomic distribution of this mark and link it to transcriptional repression.
CRISPR-based genetic screens
CRISPR knockout screens targeting VprBP/DCAF1 and related chromatin modifiers can identify genes that regulate H2AT120 phosphorylation and its downstream effects.
How CRISPR Can Be Used to Study GO:1990244 histone H2AT120 kinase activity
Knockout
CRISPR knockout of VprBP/DCAF1 can abolish H2AT120 kinase activity, allowing researchers to test its requirement for gene silencing and tumorigenesis.
Point Mutation
Introducing kinase-dead point mutations in VprBP/DCAF1 can separate its kinase activity from its scaffolding functions, directly testing the role of GO:1990244.
Knock-in
Knock-in of H2A T120A or T120D mutations can prevent or mimic phosphorylation, revealing the functional consequences of the modification.
Overexpression
Overexpression of wild-type or mutant VprBP/DCAF1 can drive aberrant H2A phosphorylation and gene silencing, modeling cancer-associated states.
How EDITGENE Supports histone H2AT120 kinase activity Research
Researchers studying histone H2AT120 kinase activity-related genes often need to determine whether a candidate gene is causally involved in the modification, gene silencing, or disease phenotypes. EDITGENE provides CRISPR-based cell model services to enable these functional studies.
Contact EDITGENE today to design your custom CRISPR model for histone H2AT120 kinase activity research.
Frequently Asked Questions About histone H2AT120 kinase activity
What is histone H2AT120 kinase activity?
It is a molecular function (GO:1990244) that catalyzes the phosphorylation of histone H2A at threonine 120 using ATP, producing ADP and H2A-phosphothreonine 120.
What genes are involved in histone H2AT120 kinase activity?
The main gene reported is VprBP/DCAF1, which has intrinsic kinase activity targeting histone H2A. Other related genes include Bub1 and TIP60, which regulate centromeric H2AT120 phosphorylation.
Which enzyme phosphorylates histone H2A at T120?
VprBP/DCAF1 has been shown to possess intrinsic kinase activity that phosphorylates histone H2A at T120.
What is the role of H2AT120 phosphorylation in cancer?
It contributes to aberrant gene silencing in prostate cancer, colon cancer, and melanoma through VprBP/DCAF1-mediated mechanisms.
How is H2AT120 phosphorylation regulated during mitosis?
TIP60 acetylation of Bub1 regulates centromeric H2AT120 phosphorylation, which is required for faithful chromosome segregation.
What diseases are associated with histone H2AT120 kinase activity?
Prostate cancer, colon cancer, melanoma, and bone-related osteoclast differentiation have been linked to this activity.
Can CRISPR be used to study histone H2AT120 kinase activity?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models can be used to dissect the function of VprBP/DCAF1 and H2A T120 phosphorylation.
What methods measure histone H2AT120 phosphorylation?
In vitro kinase assays, phospho-specific Western blotting, ChIP-seq, and immunofluorescence are commonly used.
Is there a kinase inhibitor that affects H2AT120 phosphorylation?
OTSSP167 abrogates the mitotic checkpoint by inhibiting multiple mitotic kinases, which may include those acting on H2A.
What is the GO ID for histone H2AT120 kinase activity?
The GO ID is GO:1990244.
Conclusion
GO:1990244 histone H2AT120 kinase activity defines a specific enzymatic reaction that links ATP-dependent phosphorylation to chromatin regulation. VprBP/DCAF1 is the best-characterized enzyme for this activity, and its role in gene silencing and tumorigenesis across prostate cancer, colon cancer, and melanoma highlights the importance of this modification. Regulation by TIP60-Bub1 signaling and involvement in osteoclast differentiation further broaden its biological significance. Continued research using CRISPR models and kinase assays will clarify how this activity can be targeted in disease.
References
- 1. Kim S et al.. 2026. VprBP drives prostate tumorigenesis by its kinase activity targeting histone H2A.. Cell Commun Signal 24(1) PMID: 42192547
- 2. Kim K et al.. 2013. VprBP has intrinsic kinase activity targeting histone H2A and represses gene transcription.. Mol Cell 52(3):459-67 PMID: 24140421
- 3. Ghate NB et al.. 2023. Phosphorylation and stabilization of EZH2 by DCAF1/VprBP trigger aberrant gene silencing in colon cancer.. Nat Commun 14(1):2140 PMID: 37069142
- 4. Shin Y et al.. 2023. VprBP/DCAF1 Triggers Melanomagenic Gene Silencing through Histone H2A Phosphorylation.. Biomedicines 11(9) PMID: 37760992
- 5. Ji W et al.. 2016. OTSSP167 Abrogates Mitotic Checkpoint through Inhibiting Multiple Mitotic Kinases.. PLoS One 11(4):e0153518 PMID: 27082996
- 6. Shin Y et al.. 2023. VprBP/DCAF1 triggers melanomagenic gene silencing through histone H2A phosphorylation.. Res Sq PMID: 37293029
- 7. Sun M et al.. 2024. TIP60 acetylation of Bub1 regulates centromeric H2AT120 phosphorylation for faithful chromosome segregation.. Sci China Life Sci 67(9):1957-1969 PMID: 38763998
- 8. Shin Y et al.. 2024. VprBP regulates osteoclast differentiation via an epigenetic mechanism involving histone H2A phosphorylation.. Epigenetics Chromatin 17(1):35 PMID: 39587626
