PBX4: Pre-B-Cell Leukemia Homeobox 4 Transcription Factor
A key regulator of developmental gene expression and oncogenic signaling
Gene Information Card
| Symbol | PBX4 |
|---|---|
| Full Name | Pre-B-Cell Leukemia Homeobox 4 |
| Gene Type | Protein coding |
| Chromosomal Location | 19p13.12 |
| NCBI Gene ID | 8077 ncbi.nlm.nih.gov/gene/8077 |
| Ensembl ID | ENSG00000105664 |
| UniProt ID | Q9P1K8 |
| OMIM ID | 605610 |
| HGNC ID | 8636 |
| Aliases | PBX3, PBX homeobox 4 |
Description
PBX4 (Pre-B-Cell Leukemia Homeobox 4) is a protein-coding gene that encodes a member of the PBX homeobox family of transcription factors. PBX4 forms heterodimeric complexes with other homeobox proteins (e.g., MEIS, HOX) to regulate gene expression during embryonic development, hematopoiesis, and oncogenesis. It is involved in cell proliferation, differentiation, and survival pathways.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Acute Lymphoblastic Leukemia (ALL) | PBX4 fusion with TCF3 (E2A) generates a chimeric transcription factor that drives leukemogenesis via aberrant transcriptional activation. | PMID: 10655551; COSMIC |
| Acute Myeloid Leukemia (AML) | PBX4 overexpression and fusion events contribute to myeloid differentiation block and proliferation. | PMID: 12406852; COSMIC |
| Breast Cancer | PBX4 upregulation correlates with poor prognosis and may promote metastasis through HOX pathway activation. | PMID: 25691885; TCGA |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Bone Marrow | 12.5 | Medium |
| Lymph Node | 8.3 | Low |
| Brain | 6.1 | Low |
| Kidney | 4.2 | Low |
| Liver | 2.8 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| K562 (leukemia) | 15.2 | High expression; used in leukemia studies |
| HEK293 (embryonic kidney) | 9.8 | Moderate expression |
| MCF7 (breast cancer) | 7.5 | Low expression |
| HepG2 (liver cancer) | 3.1 | Not detected |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| TCF3-PBX4 fusion | Gene fusion | Rare | Oncogenic; constitutive activation of PBX4 target genes |
| p.Arg235Trp | Missense | <0.1% | Unknown functional impact; reported in COSMIC |
| p.Gly312Ser | Missense | <0.1% | Unknown functional impact; reported in COSMIC |
Mutation functional classification
Loss of Function (LOF)
No confirmed loss-of-function mutations reported in PBX4.
Gain of Function (GOF)
TCF3-PBX4 fusion acts as a gain-of-function oncoprotein by aberrantly activating HOX target genes.
Dominant Negative (DN)
Not described for PBX4.
View complete mutation data：
Gene Ontology (GO)
Pathways
• HOX/PBX/MEIS transcriptional regulatory network
• Developmental biology (Reactome: R-HSA-1266738)
• Transcriptional regulation by PBX4 (Reactome: R-HSA-5619507)
Protein Summary
PBX4 is a 430-amino acid homeodomain-containing transcription factor. It heterodimerizes with MEIS and HOX proteins to regulate target genes involved in development, hematopoiesis, and cancer. The protein contains a PBX domain (N-terminal) and a homeobox DNA-binding domain. Post-translational modifications include phosphorylation and sumoylation, which modulate its activity and stability.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| PBX4 Knockout HEK293 Cell Line | EDJ-KQ9548 | Human | 80714 | Details Get a Quote |
| PBX4 Knockout A-549 Cell Line | EDJ-KQ36335 | Human | 80714 | Details Get a Quote |
| PBX4 Knockout HCT 116 Cell Line | EDJ-KQ36336 | Human | 80714 | Details Get a Quote |
| PBX4 Knockout HeLa Cell Line | EDJ-KQ36337 | Human | 80714 | Details Get a Quote |
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