KDM4B
Lysine Demethylase 4B: A Key Epigenetic Regulator in Cancer and Development
Gene Information Card
| Symbol | KDM4B |
|---|---|
| Full Name | Lysine Demethylase 4B |
| Gene Type | Protein-coding |
| Chromosomal Location | 19p13.3 |
| NCBI Gene ID | 23030 ncbi.nlm.nih.gov/gene/23030 |
| Ensembl ID | ENSG00000127663 |
| UniProt ID | O94953 |
| OMIM ID | 609765 |
| HGNC ID | 29136 |
| Aliases | JMJD2B, TDRD14B |
Description
KDM4B (lysine demethylase 4B) encodes a member of the Jumonji domain-containing histone demethylase family. The protein specifically demethylates di- and tri-methylated lysine 9 of histone H3 (H3K9me2/me3) and, to a lesser extent, H3K36me2/me3, acting as a key epigenetic regulator of gene expression. KDM4B is involved in chromatin remodeling, transcriptional activation, DNA replication, and cellular differentiation. Overexpression or gain-of-function mutations are frequently observed in various cancers, including breast, prostate, colorectal, and lung cancers, where it promotes oncogenic pathways. It also plays roles in stem cell maintenance and metabolic regulation.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Breast Cancer | Overexpression leads to H3K9me3 demethylation at oncogene promoters, enhancing proliferation and metastasis. | COSMIC, ClinVar |
| Prostate Cancer | Amplification and overexpression promote androgen receptor signaling and tumor growth. | COSMIC, NCBI |
| Colorectal Cancer | Upregulation correlates with poor prognosis; demethylates H3K9me3 at Wnt target genes. | COSMIC, PubMed |
| Lung Cancer | Gain-of-function mutations increase cell migration and invasion. | COSMIC, ClinVar |
| Acute Myeloid Leukemia | Fusion partners or overexpression disrupt differentiation via H3K9me3 misregulation. | COSMIC, PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 12.5 | Medium |
| Bone Marrow | 8.2 | Medium |
| Lymph Node | 6.7 | Low |
| Brain | 4.3 | Low |
| Breast | 3.1 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| MCF7 (Breast Cancer) | 15.2 | High expression |
| PC3 (Prostate Cancer) | 11.8 | High expression |
| HCT116 (Colorectal Cancer) | 9.5 | Medium expression |
| A549 (Lung Cancer) | 7.3 | Medium expression |
| K562 (Leukemia) | 6.1 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1124A>G (p.Asn375Ser) | Missense | <1% | Altered substrate specificity; potential gain-of-function |
| c.1672C>T (p.Arg558Trp) | Missense | <1% | Reduced catalytic activity; loss-of-function |
| c.2101_2102insA (p.Thr701Asnfs*2) | Frameshift | <1% | Truncated protein; loss-of-function |
| Amplification | Copy number gain | 5-10% in breast cancer | Increased expression; oncogenic |
Mutation functional classification
Loss of Function (LOF)
Missense mutations (e.g., p.Arg558Trp) or frameshift insertions that reduce or abolish demethylase activity, impairing H3K9me3 removal and gene activation.
Gain of Function (GOF)
Missense mutations (e.g., p.Asn375Ser) that enhance demethylase activity or alter substrate specificity, leading to increased oncogene expression.
Dominant Negative (DN)
Not well-documented; however, truncated forms may interfere with wild-type KDM4B function in heterodimeric complexes.
View complete mutation data：
Gene Ontology (GO)
| • Histone H3-K9 demethylation | • Chromatin remodeling |
| • Transcription | • DNA-templated |
| • Cell cycle regulation | • DNA repair |
| • Negative regulation of cell differentiation |
Pathways
• Epigenetic regulation of gene expression
• Wnt signaling pathway
• Estrogen receptor signaling
• p53 signaling pathway
• Cell cycle
Protein Summary
KDM4B is a 1096-amino acid protein containing a JmjN domain, a JmjC domain (catalytic), two PHD-type zinc fingers, and two Tudor domains. The JmjC domain uses Fe(II) and α-ketoglutarate as cofactors to demethylate H3K9me2/me3 and H3K36me2/me3. The Tudor domains recognize methylated histones, facilitating chromatin targeting. KDM4B interacts with transcription factors such as AR, ERα, and MYC, and is regulated by ubiquitination and phosphorylation. Its overexpression in cancers makes it a therapeutic target for small-molecule inhibitors.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| KDM4B Knockout HEK293 Cell Line | EDJ-KQ7780 | Human | 23030 | Details Get a Quote |
| KDM4B Knockout A-549 Cell Line | EDJ-KQ33260 | Human | 23030 | Details Get a Quote |
| KDM4B Knockout HCT 116 Cell Line | EDJ-KQ33261 | Human | 23030 | Details Get a Quote |
| KDM4B Knockout HeLa Cell Line | EDJ-KQ33262 | Human | 23030 | Details Get a Quote |
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