CBX6: Chromobox Protein 6 – A Key Regulator in Polycomb Repressive Complex 1
Comprehensive genomic and functional analysis of CBX6, a component of the Polycomb group (PcG) family involved in chromatin remodeling and gene silencing.
Gene Information Card
| Symbol | CBX6 |
|---|---|
| Full Name | Chromobox 6 |
| Gene Type | Protein coding |
| Chromosomal Location | 22q13.1 |
| NCBI Gene ID | 23466 ncbi.nlm.nih.gov/gene/23466 |
| Ensembl ID | ENSG00000100225 |
| UniProt ID | O95503 |
| OMIM ID | 617478 |
| HGNC ID | 1556 |
| Aliases | Pc, MGC126514, MGC126516 |
Description
CBX6 (Chromobox 6) encodes a component of the Polycomb repressive complex 1 (PRC1). It binds histone H3 lysine 27 trimethylation (H3K27me3) via its chromodomain and contributes to chromatin compaction and transcriptional repression. CBX6 is involved in developmental processes, stem cell maintenance, and is implicated in various cancers.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Breast cancer | CBX6 overexpression correlates with poor prognosis; may promote proliferation via PRC1-mediated repression of tumor suppressors. | PMID: 30356099 |
| Hepatocellular carcinoma | CBX6 upregulation associated with aggressive tumor features and shorter survival; potential oncogenic role. | PMID: 31270520 |
| Prostate cancer | CBX6 expression altered in metastatic vs. primary tumors; possible role in androgen receptor signaling. | PMID: 28991257 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 12.5 | Medium |
| Bone marrow | 8.3 | Low |
| Lymph node | 7.1 | Low |
| Brain (cortex) | 6.4 | Low |
| Liver | 5.2 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 15.2 | Embryonic kidney; high expression |
| HeLa | 11.8 | Cervical carcinoma; moderate expression |
| K562 | 9.4 | Leukemia; moderate expression |
| MCF7 | 7.6 | Breast cancer; low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.437C>T (p.Ala146Val) | Missense | 0.02% (gnomAD) | Unknown; located in chromodomain, may affect H3K27me3 binding |
| c.622G>A (p.Gly208Arg) | Missense | 0.01% (gnomAD) | Unknown; in C-terminal region, potential impact on protein stability |
| c.100_102del (p.Lys34del) | In-frame deletion | Rare | Unknown; may alter chromodomain structure |
Mutation functional classification
Loss of Function (LOF)
No confirmed loss-of-function variants reported in ClinVar or COSMIC for CBX6.
Gain of Function (GOF)
No confirmed gain-of-function variants reported.
Dominant Negative (DN)
No confirmed dominant-negative variants reported.
View complete mutation data：
Gene Ontology (GO)
| • chromatin binding (GO:0003682) | • protein binding (GO:0005515) |
| • chromatin organization (GO:0006325) | • chromatin silencing (GO:0006342) |
| • nucleus (GO:0005634) | • histone methyltransferase activity (H3-K27 specific) (GO:0035097) |
Pathways
• Polycomb repressive complex 1 (PRC1) – Gene silencing
• Chromatin modifying enzymes – KEGG hsa05202 (Transcriptional misregulation in cancer)
Protein Summary
CBX6 is a 412-amino acid protein containing an N-terminal chromodomain that recognizes H3K27me3 marks. It is a core component of PRC1, which ubiquitinates histone H2A at lysine 119 (H2AK119ub) and compacts chromatin to silence target genes. CBX6 is widely expressed, with highest levels in testis and bone marrow. Its dysregulation is linked to cancer progression.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CBX6 Knockout HEK293 Cell Line | EDJ-KQ8021 | Human | 23466 | Details Get a Quote |
| CBX6 Knockout A-549 Cell Line | EDJ-KQ33794 | Human | 23466 | Details Get a Quote |
| CBX6 Knockout HCT 116 Cell Line | EDJ-KQ33795 | Human | 23466 | Details Get a Quote |
| CBX6 Knockout HeLa Cell Line | EDJ-KQ33796 | Human | 23466 | Details Get a Quote |
