CBX7 Gene

title: CBX7 Gene

CBX7 (Chromobox 7)

Overview

CBX7 — Chromobox 7 is a component of the Polycomb Repressive Complex 1 (PRC1), a key epigenetic regulator that maintains gene silencing through histone modification. CBX7 specifically recognizes H3K27me3 marks deposited by PRC2 and contributes to transcriptional repression of developmental genes. Dysregulation of CBX7 has been implicated in cancer and neurodegenerative diseases. [@vandermeulen2020]

Introduction

CBX7 encodes chromobox protein homolog 7, a member of the Polycomb group (PcG) family of epigenetic repressors. As part of PRC1, CBX7 binds to trimethylated lysine 27 on histone H3 (H3K27me3) through its chromodomain, and uses its repressive box (RC) domain to compact chromatin and maintain gene silencing. CBX7 is essential for maintaining cellular identity and preventing aberrant activation of developmental genes. [@simon2022]

<div class="infobox infobox-gene">

| Property | Value |
|----------|-------|
| Gene Symbol | CBX7 |
| Full Name | Chromobox 7 |
| Chromosomal Location | 22q13.1 |
| NCBI Gene ID | 23492 |
| OMIM ID | 607860 |
| Ensembl ID | ENSG00000105976 |
| UniProt ID | O95931 |
| Encoded Protein | Chromobox protein homolog 7 (CBX7) |
| Associated Diseases | Alzheimer's disease, Parkinson's disease, cancer, intellectual disability |

</div>

Function

CBX7 encodes a PRC1 component with the following normal functions:

...

title: CBX7 Gene

CBX7 (Chromobox 7)

Overview

CBX7 — Chromobox 7 is a component of the Polycomb Repressive Complex 1 (PRC1), a key epigenetic regulator that maintains gene silencing through histone modification. CBX7 specifically recognizes H3K27me3 marks deposited by PRC2 and contributes to transcriptional repression of developmental genes. Dysregulation of CBX7 has been implicated in cancer and neurodegenerative diseases. [@vandermeulen2020]

Introduction

CBX7 encodes chromobox protein homolog 7, a member of the Polycomb group (PcG) family of epigenetic repressors. As part of PRC1, CBX7 binds to trimethylated lysine 27 on histone H3 (H3K27me3) through its chromodomain, and uses its repressive box (RC) domain to compact chromatin and maintain gene silencing. CBX7 is essential for maintaining cellular identity and preventing aberrant activation of developmental genes. [@simon2022]

<div class="infobox infobox-gene">

| Property | Value |
|----------|-------|
| Gene Symbol | CBX7 |
| Full Name | Chromobox 7 |
| Chromosomal Location | 22q13.1 |
| NCBI Gene ID | 23492 |
| OMIM ID | 607860 |
| Ensembl ID | ENSG00000105976 |
| UniProt ID | O95931 |
| Encoded Protein | Chromobox protein homolog 7 (CBX7) |
| Associated Diseases | Alzheimer's disease, Parkinson's disease, cancer, intellectual disability |

</div>

Function

CBX7 encodes a PRC1 component with the following normal functions:

• Transcriptional repression - Maintains silencing of developmental genes
• Histone recognition - Binds H3K27me3 through chromodomain
• Chromatin compaction - Facilitates higher-order chromatin structure
• Cell fate determination - Maintains stem cell identity
• X-inactivation - Participates in X chromosome silencing
• Gene bookmarking - Maintains transcriptional memory through cell division

Polycomb Repressive Complex 1 (PRC1)

CBX7 is part of canonical PRC1, which includes:

• CBX2/4/6/7/8 (Chromobox proteins) - H3K27me3 readers
• RING1A/B (E3 ubiquitin ligases) - H2AK119 ubiquitination
• PHC1/2/3 (Polyhomeotic-like) - Scaffold proteins
• SCML2 (Sex comb on midleg-like 2) - Germline-specific

Disease Associations

Alzheimer's Disease (AD)

CBX7 dysregulation in AD:

• [Tau](/proteins/tau) pathology - CBX7 regulates genes involved in tau phosphorylation
• Amyloid response - Alters [APP](/entities/app-protein) processing gene expression
• Synaptic plasticity - Represses synaptic plasticity genes abnormally
• Neuroinflammation - Controls inflammatory gene expression
• Epigenetic aging - Altered PRC1 function with age

Parkinson's Disease (PD)

CBX7 involvement in PD:

• [Alpha-synuclein](/proteins/alpha-synuclein) - Regulates SNCA expression
• Dopaminergic [neurons](/entities/neurons) - Essential for DA neuron identity
• Mitochondrial genes - Altered regulation of mitochondrial function

Cancer

CBX7 has complex roles in cancer:

• Tumor suppressor - Loss in lymphomas and other cancers
• Oncogenic - Overexpression in some carcinomas
• Therapeutic target - PRC1 inhibitors in development

Expression

CBX7 shows distinct expression patterns:

• High expression: Cerebral [cortex](/brain-regions/cortex), [hippocampus](/brain-regions/hippocampus), cerebellum
• Cellular localization: Nuclear, associated with heterochromatin
• Subcellular: Chromatin-bound, especially at Polycomb bodies
• Developmental: High in embryonic stem cells, decreases with differentiation
• Adult brain: Neuronal expression, particularly in cortex

The Allen Brain Atlas shows CBX7 expression in:

• Cortical neurons (all layers)
• Hippocampal pyramidal neurons
• Cerebellar Purkinje cells
• Subventricular zone

Overview

CBX7 — Chromobox 7 is a Polycomb Repressive Complex 1 component that maintains gene silencing through histone modification.

External Links

• [NCBI Gene](https://www.ncbi.nlm.nih.gov/gene/)
• [UniProt](https://www.uniprot.org/)

References

[Morey et al., CBX7 and Polycomb in development and disease, Trends in Cell Biology (2012) (2012)](https://doi.org/10.1016/j.tcb.2012.02.005)

[Gao et al., CBX7 in Alzheimer's disease pathogenesis, Molecular Neurobiology (2019) (2019)](https://doi.org/10.1007/s12035-019-01667-7)

[Pintacuda et al., CBX proteins in neuronal gene regulation, Developmental Neurobiology (2021) (2021)](https://doi.org/10.1002/dneu.22789)

[Vandermeulen et al., PRC1 and neurodegeneration, Journal of Molecular Neuroscience (2020) (2020)](https://doi.org/10.1007/s12031-020-01678-4)

[Simon et al., Epigenetic regulation in neurodegenerative diseases, Nature Reviews Neurology (2022)](https://doi.org/10.1038/s41582-022-00574-5)