GO:0061638 CENP-A containing chromatin: Components, Assembly and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0061638 (CENP-A containing chromatin) is the specialized centromeric chromatin enriched in CENP-A nucleosomes that provides the platform for kinetochore assembly and microtubule attachment.
• CENP-A replaces histone H3 in centromeric nucleosomes and forms a structurally distinct nucleosome that acts as an allosteric scaffold for centromere factors.
• Human centromeric CENP-A chromatin is homotypic and octameric throughout the cell cycle, maintaining a stable epigenetic mark for centromere identity.
• CENP-A assembly is spatially and temporally controlled, with deposition occurring in a specific window of the cell cycle and requiring dedicated assembly factors.
• Deregulated CENP-A chromatin is linked to genome instability and cancer, making it a target for mechanistic and translational studies.
• CRISPR-based knockout, knock-in, point-mutation, and overexpression models enable causal dissection of CENP-A chromatin components and their roles in disease.
Description
CENP-A containing chromatin (GO:0061638) is the centromeric core chromatin that is enriched for nucleosomes containing the histone H3 variant CENP-A. This specialized chromatin is a cellular component that forms a three-dimensional structure providing a platform for kinetochore assembly and microtubule attachment, and it is essential for faithful chromosome segregation. Unlike bulk chromatin, CENP-A chromatin is epigenetically defined and maintained, serving as the structural and functional foundation of the centromere. Researchers study GO:0061638 to understand how centromere identity is established and propagated, how kinetochores are built on a CENP-A nucleosome platform, and how defects in this chromatin contribute to genome instability and disease. Structural and cell-biological studies have revealed that the CENP-A nucleosome is a sensitive allosteric scaffold that integrates DNA and chromatin factor interactions, and that centromeric tri-nucleosomes containing a central CENP-A nucleosome adopt specific architectures. Because CENP-A chromatin is a central determinant of chromosome inheritance, it is a high-value target for CRISPR-based functional genomics and for developing models of centromere dysfunction in cancer and other diseases.
CENP-A containing chromatin At A Glance
| GO ID | GO:0061638 |
|---|---|
| GO term | CENP-A containing chromatin |
| Ontology | cellular_component |
| Synonym | centromeric core domain chromatin; centromeric core region chromatin; chromatin containing CENP-A; nuclear CENP-A containing chromatin |
| Major function | Provides a structural platform for kinetochore assembly and microtubule attachment at the centromere |
| Composition | Enriched in CENP-A-containing nucleosomes, with CENP-A replacing histone H3 in centromeric nucleosomes |
| Structural feature | Forms a three-dimensional chromatin structure that acts as an allosteric scaffold for DNA and chromatin factors |
| Cell cycle property | Human centromeric CENP-A chromatin is homotypic and octameric at all cell cycle points |
| Assembly control | CENP-A deposition is spatially and temporally controlled during the cell cycle |
What Is GO:0061638?
GO:0061638 (CENP-A containing chromatin) is defined as the specialized chromatin located in the centromeric core region, or across the entire centromeric region in organisms with point centromeres, which is enriched for CENP-A-containing nucleosomes. This chromatin forms a three-dimensional structure that provides a platform for kinetochore assembly and microtubule attachment. In other words, it is the centromere-specific chromatin state in which canonical histone H3 is largely replaced by CENP-A, creating a unique nucleosomal surface that recruits kinetochore components and supports chromosome segregation.
Why Is CENP-A containing chromatin Important in Cell Biology?
CENP-A containing chromatin is essential for centromere identity and faithful chromosome segregation, and its dysfunction is directly linked to genome instability and cancer. Because it provides the platform for kinetochore assembly and microtubule attachment, understanding GO:0061638 is fundamental to chromosome biology and to explaining how errors in centromere chromatin contribute to aneuploidy and tumorigenesis.
CENP-A containing chromatin (GO:0061638)
• Defines centromere identity as an epigenetic mark through CENP-A nucleosome enrichment.
• Provides the structural platform for kinetochore assembly and microtubule attachment.
• Ensures faithful chromosome segregation and genome stability.
• Its deregulation is associated with cancer and chromosomal instability.
• Serves as an allosteric scaffold that integrates DNA and chromatin factor interactions.
• Its assembly is temporally restricted and spatially controlled during the cell cycle.
• Human CENP-A chromatin is homotypic and octameric throughout the cell cycle, providing a stable mark.
• Structural studies of CENP-A nucleosomes and tri-nucleosomes inform centromeric chromatin architecture.
• Provides a target for CRISPR-based functional dissection of centromere components.
• Offers a mechanistic entry point for understanding aneuploidy-related diseases.
What Happens During CENP-A containing chromatin assembly?
(未命名小节)
In simple terms: CENP-A is loaded into centromeric DNA at a specific time in the cell cycle to mark the centromere.
CENP-A containing chromatin is assembled through a spatially and temporally controlled process in which CENP-A is deposited into centromeric DNA, replacing canonical H3 in centromeric nucleosomes. This deposition is restricted to a specific window of the cell cycle, ensuring that centromere identity is propagated faithfully after DNA replication. The resulting CENP-A nucleosomes form a specialized chromatin domain that serves as the foundation for kinetochore assembly.
Propagation and maintenance of CENP-A chromatin
In simple terms: Once established, the CENP-A mark is maintained through cell divisions so the centromere stays in the same place.
CENP-A chromatin is maintained as an epigenetic mark, and human centromeric CENP-A chromatin has been shown to be a homotypic, octameric nucleosome at all cell cycle points. This stable composition allows the centromere to be propagated through replication and mitosis, providing a persistent platform for kinetochore assembly.
Structure and Composition of CENP-A containing chromatin
In simple terms: The centromere chromatin is built from CENP-A-containing nucleosomes that create a unique surface for other proteins to bind.
CENP-A containing chromatin is enriched for CENP-A-containing nucleosomes, in which CENP-A replaces histone H3 and creates a structurally distinct nucleosome. Structural biology has shown that the CENP-A nucleosome is a chromatin-embedded pedestal for the centromere, and cryo-EM structures of centromeric tri-nucleosomes containing a central CENP-A nucleosome reveal how these units are organized. The CENP-A nucleosome also acts as a sensitive allosteric scaffold for DNA and chromatin factors, meaning its conformation can change in response to binding partners.
Molecular Mechanism of CENP-A containing chromatin function
In simple terms: The CENP-A nucleosome works like a docking station that recruits kinetochore proteins and connects chromosomes to microtubules.
At the molecular level, CENP-A containing chromatin provides a three-dimensional platform for kinetochore assembly and microtubule attachment. The CENP-A nucleosome presents a unique surface that recruits centromere and kinetochore factors, and its allosteric properties allow it to integrate signals from DNA and chromatin-binding proteins. This molecular architecture ensures that the kinetochore is built at the correct chromosomal location and that microtubules attach properly during mitosis.
Regulation of CENP-A chromatin assembly
In simple terms: Cells control when and where CENP-A is loaded so that centromeres are marked correctly after DNA replication.
CENP-A assembly into centromeric chromatin is regulated spatially and temporally, with deposition occurring in a defined cell cycle window. This regulation ensures that CENP-A chromatin is propagated once per cell cycle and that centromere identity is maintained. Disruption of this regulation can lead to altered CENP-A chromatin and genome instability.
Key Genes Involved in GO:0061638 CENP-A containing chromatin
The following genes and proteins are central to the structure, assembly, and function of CENP-A containing chromatin (GO:0061638).
| Gene | Major Role | Research Relevance |
|---|---|---|
| CENPA | Histone H3 variant that replaces H3 in centromeric nucleosomes | Core mark of CENP-A containing chromatin; knockout and knock-in models reveal centromere identity mechanisms |
| CENPB | Centromere protein B that binds centromeric DNA | Contributes to centromere architecture and is studied in centromere chromatin models |
| CENPC | Inner kinetochore protein that binds CENP-A chromatin | Links CENP-A chromatin to kinetochore assembly |
| CENPT | Inner kinetochore component of the CCAN | Required for kinetochore assembly on CENP-A chromatin |
| CENPW | Inner kinetochore component of the CCAN | Required for kinetochore assembly on CENP-A chromatin |
| CENPS | Inner kinetochore component of the CCAN | Required for kinetochore assembly on CENP-A chromatin |
| CENPX | Inner kinetochore component of the CCAN | Required for kinetochore assembly on CENP-A chromatin |
| HJURP | CENP-A-specific chaperone that deposits CENP-A | Controls CENP-A assembly and centromere propagation |
| NPM1 | Histone chaperone involved in chromatin assembly | Participates in CENP-A chromatin assembly pathways |
| RSF1 | Chromatin remodeling factor | Implicated in centromere chromatin structure and function |
| KDM4A | Histone demethylase | Modulates centromere chromatin state |
| SUPT16H | Chromatin assembly factor subunit | Contributes to centromere chromatin assembly |
| SSRP1 | Chromatin assembly factor subunit | Contributes to centromere chromatin assembly |
| ATRX | Chromatin remodeler | Influences centromere chromatin and genome stability |
| DAXX | Histone chaperone | Influences centromere chromatin and genome stability |
| MIS18A | CENP-A assembly factor | Required for CENP-A deposition at centromeres |
| MIS18BP1 | CENP-A assembly factor | Required for CENP-A deposition at centromeres |
How Is CENP-A containing chromatin Regulated?
CENP-A containing chromatin is regulated primarily through the spatial and temporal control of CENP-A assembly during the cell cycle. CENP-A deposition is restricted to a specific window, ensuring that centromere identity is propagated once per cell cycle. This regulation involves dedicated assembly factors and chaperones that target CENP-A to centromeric DNA. In addition, the CENP-A nucleosome itself is an allosteric scaffold whose conformation and interactions with DNA and chromatin factors can modulate downstream kinetochore assembly. Disruption of this regulation can alter CENP-A chromatin and contribute to genome instability.
CENP-A containing chromatin and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| CENPA | Cancer and chromosomal instability | CENPA knockout and overexpression cell models |
| HJURP | Centromere dysfunction and cancer | HJURP knockout and point-mutation models |
| CENPC | Kinetochore assembly defects | CENPC knockout and tagged knock-in models |
| MIS18A | CENP-A deposition defects | MIS18A knockout and knock-in models |
| ATRX | Chromatin remodeling and genome instability | ATRX knockout and overexpression models |
CENP-A chromatin and cancer
Deregulation of CENP-A containing chromatin is linked to genome instability and cancer, as CENP-A chromatin is essential for faithful chromosome segregation. Altered CENP-A levels or assembly can lead to chromosomal instability, a hallmark of many cancers. Because CENP-A chromatin provides the platform for kinetochore assembly, defects in this process can drive aneuploidy and tumor progression.
CENP-A chromatin and chromosomal instability syndromes
Defects in centromere chromatin assembly and maintenance can result in chromosomal instability, which underlies various developmental and cancer predisposition conditions. The spatial and temporal control of CENP-A assembly is critical for preventing such instability. Research into CENP-A chromatin structure and assembly is therefore relevant to understanding diseases characterized by chromosome missegregation.
CENP-A chromatin as a therapeutic target
Because CENP-A chromatin is central to centromere function and is deregulated in cancer, components of this chromatin and its assembly machinery are being explored as potential therapeutic targets. Structural insights into the CENP-A nucleosome and its allosteric properties may inform drug discovery efforts.
From CENP-A containing chromatin-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| What is the role of CENP-A in centromere identity? | CENPA knockout and knock-in cell lines |
| How does CENP-A assembly occur during the cell cycle? | Tagged knock-in of CENPA and assembly factors |
| What is the structural impact of CENP-A mutations? | Point-mutation knock-in of CENPA |
| How does CENP-A overexpression affect genome stability? | CENPA overexpression cell models |
| What factors are required for kinetochore assembly on CENP-A chromatin? | Knockout of inner kinetochore genes |
| How is CENP-A chromatin propagated epigenetically? | Knock-in and knockout of assembly factors |
How to Study the CENP-A containing chromatin Process
| Method | What It Measures | Typical Application |
|---|---|---|
| ChIP-seq | Genomic localization and enrichment of CENP-A chromatin | Mapping centromeric domains and CENP-A deposition changes |
| Cryo-EM | Three-dimensional structure of CENP-A nucleosomes and tri-nucleosomes | Understanding centromeric chromatin architecture |
| Live-cell imaging | Spatial and temporal dynamics of CENP-A assembly | Cell cycle control of centromere chromatin |
| Biochemical binding assays | Interactions between CENP-A nucleosomes and chromatin factors | Allosteric scaffold function of CENP-A chromatin |
| Mass spectrometry | Composition of CENP-A nucleosome complexes | Identifying associated proteins and modifications |
| CRISPR knockout screening | Genes required for CENP-A chromatin function | Functional genomics of centromere assembly |
| Knock-in tagging | Localization and dynamics of CENP-A and assembly factors | Tracking centromere chromatin in live cells |
| Transcriptomics | Gene expression changes upon CENP-A perturbation | Linking CENP-A chromatin to cellular pathways |
Chromatin immunoprecipitation and sequencing (ChIP-seq)
ChIP-seq using anti-CENP-A antibodies maps the genomic location and enrichment of CENP-A containing chromatin, allowing researchers to define centromeric domains and assess changes in CENP-A deposition.
Structural biology (cryo-EM and crystallography)
Cryo-EM and crystallographic studies of CENP-A nucleosomes and centromeric tri-nucleosomes reveal the three-dimensional architecture of CENP-A containing chromatin and its interactions with DNA and chromatin factors.
Cell cycle and live-cell imaging
Live-cell imaging of fluorescently tagged CENP-A and kinetochore proteins tracks the spatial and temporal assembly of CENP-A containing chromatin across the cell cycle.
Biochemical reconstitution and binding assays
Reconstituted CENP-A nucleosomes and binding assays measure how CENP-A chromatin interacts with DNA and chromatin factors, revealing its allosteric scaffold properties.
How CRISPR Can Be Used to Study GO:0061638 CENP-A containing chromatin
Knockout
CRISPR knockout of CENPA or its assembly factors (e.g., HJURP, MIS18A) eliminates or reduces CENP-A containing chromatin, allowing researchers to test its requirement for kinetochore assembly and chromosome segregation.
Point Mutation
Point-mutation knock-in of CENPA can be used to dissect the structural determinants of CENP-A nucleosome function, including its allosteric scaffold properties and interactions with chromatin factors.
Knock-in
Tagged knock-in of CENPA and centromere components enables live-cell imaging and biochemical purification of CENP-A containing chromatin, revealing its dynamics and composition.
Overexpression
Overexpression of CENPA or its assembly factors can model CENP-A chromatin deregulation, which is associated with genome instability and cancer, and can be used to study downstream cellular consequences.
How EDITGENE Supports CENP-A containing chromatin Research
Researchers studying CENP-A containing chromatin-related genes often need to determine whether a candidate gene is causally involved in centromere assembly, kinetochore function, or genome stability. EDITGENE provides CRISPR-based cell model services that enable precise genetic perturbations to test these hypotheses in relevant cellular contexts.
Contact EDITGENE today to design your custom CRISPR model for CENP-A containing chromatin research.
Frequently Asked Questions About CENP-A containing chromatin
What is CENP-A containing chromatin?
CENP-A containing chromatin (GO:0061638) is the specialized centromeric chromatin enriched for CENP-A-containing nucleosomes that provides a platform for kinetochore assembly and microtubule attachment.
What genes are involved in CENP-A containing chromatin?
Key genes include CENPA, HJURP, MIS18A, MIS18BP1, and inner kinetochore components such as CENPC, CENPT, and CENPW, which together build and maintain centromeric chromatin.
Where is CENP-A containing chromatin located?
It is located at the centromeric core region, or across the entire centromeric region in organisms with point centromeres.
What is the function of CENP-A containing chromatin?
It provides a three-dimensional platform for kinetochore assembly and microtubule attachment, ensuring faithful chromosome segregation.
How is CENP-A chromatin assembled?
CENP-A is deposited into centromeric DNA in a spatially and temporally controlled manner during the cell cycle, using dedicated assembly factors and chaperones.
Is CENP-A chromatin octameric?
Yes, human centromeric CENP-A chromatin has been shown to be a homotypic, octameric nucleosome at all cell cycle points.
How is CENP-A chromatin linked to cancer?
Deregulation of CENP-A chromatin is associated with genome instability and cancer, as it is essential for faithful chromosome segregation.
What methods are used to study CENP-A containing chromatin?
Common methods include ChIP-seq, cryo-EM, live-cell imaging, biochemical binding assays, and CRISPR-based functional screens.
Can CRISPR be used to study CENP-A chromatin?
Yes, CRISPR knockout, knock-in, point-mutation, and overexpression models are widely used to dissect CENP-A chromatin components and their functions.
What is the GO ID for CENP-A containing chromatin?
The GO ID is GO:0061638, under the cellular_component ontology.
Conclusion
CENP-A containing chromatin (GO:0061638) is the centromere-specific chromatin state that provides the structural platform for kinetochore assembly and microtubule attachment. Its unique composition, centered on CENP-A nucleosomes, and its cell-cycle-regulated assembly make it a central determinant of genome stability. Dysregulation of this chromatin is linked to cancer and chromosomal instability, underscoring its importance in human disease. CRISPR-based cell models and functional genomics approaches offer powerful ways to dissect the mechanisms and consequences of CENP-A chromatin function, and EDITGENE provides end-to-end services to support such research.
References
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- 3. Doğan D et al.. 2021. CENP-A Nucleosome is a Sensitive Allosteric Scaffold for DNA and Chromatin Factors.. J Mol Biol 433(6):166789 PMID: 33387534
- 4. Takizawa Y et al.. 2020. Cryo-EM Structures of Centromeric Tri-nucleosomes Containing a Central CENP-A Nucleosome.. Structure 28(1):44-53.e4 PMID: 31711756
- 5. Shukla S et al.. 2022. Centromere Chromatin Dynamics at a Glance.. Epigenomes 6(4) PMID: 36412794
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- 7. Nechemia-Arbely Y et al.. 2012. Replicating centromeric chromatin: spatial and temporal control of CENP-A assembly.. Exp Cell Res 318(12):1353-60 PMID: 22561213
- 8. Nechemia-Arbely Y et al.. 2017. Human centromeric CENP-A chromatin is a homotypic, octameric nucleosome at all cell cycle points.. J Cell Biol 216(3):607-621 PMID: 28235947
