UBQLN4
Ubiquilin 4: A key regulator of protein quality control and DNA damage response
Gene Information Card
| Symbol | UBQLN4 |
|---|---|
| Full Name | Ubiquilin 4 |
| Gene Type | Protein coding |
| Chromosomal Location | 1q22 |
| NCBI Gene ID | 56893 ncbi.nlm.nih.gov/gene/56893 |
| Ensembl ID | ENSG00000160803 |
| UniProt ID | Q9NRR5 |
| OMIM ID | 605044 |
| HGNC ID | 12506 |
| Aliases | A1U, A1Up, C1orf6, UBIN, UQN4 |
Description
UBQLN4 encodes ubiquilin 4, a member of the ubiquilin family that functions as a shuttle factor in the ubiquitin-proteasome system. It delivers ubiquitinated proteins to the proteasome for degradation and plays a critical role in the DNA damage response by regulating the stability of key repair proteins. UBQLN4 is involved in maintaining protein homeostasis and genome stability.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Prostate cancer | UBQLN4 overexpression promotes DNA repair and resistance to therapy | PMID: 31435016 |
| Breast cancer | UBQLN4 amplification correlates with poor prognosis and genomic instability | PMID: 29713085 |
| Neurodegenerative disorders | UBQLN4 mutations impair proteasomal degradation, leading to protein aggregation | PMID: 25644396 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 15.2 | Medium |
| Brain | 12.8 | Medium |
| Heart | 10.5 | Medium |
| Liver | 8.3 | Low |
| Kidney | 9.1 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK293 | 18.4 | High expression |
| HeLa | 14.7 | Medium expression |
| MCF7 | 11.2 | Medium expression |
| A549 | 9.8 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1072C>T (p.Arg358Trp) | Missense | 0.01% | Impaired proteasome binding |
| c.1456G>A (p.Glu486Lys) | Missense | 0.005% | Reduced DNA repair efficiency |
| c.1789_1791del (p.Lys597del) | In-frame deletion | 0.002% | Altered protein stability |
Mutation functional classification
Loss of Function (LOF)
Missense mutations in the UBA domain reduce ubiquitin binding and proteasomal targeting.
Gain of Function (GOF)
Amplification of UBQLN4 in cancers leads to enhanced DNA repair and therapy resistance.
Dominant Negative (DN)
Truncating mutations may interfere with wild-type ubiquilin 4 function in protein degradation.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Ubiquitin-proteasome pathway (KEGG: hsa04120)
• DNA damage response (Reactome: R-HSA-73893)
Protein Summary
Ubiquilin 4 is a 601-amino acid protein containing an N-terminal ubiquitin-like (UBL) domain and a C-terminal ubiquitin-associated (UBA) domain. It shuttles ubiquitinated substrates to the proteasome and interacts with DNA repair factors such as BRCA1 and RAD51. UBQLN4 is localized to the nucleus and cytoplasm, with elevated expression in testis and brain. Post-translational modifications include phosphorylation and ubiquitination.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| UBQLN4 Knockout HEK293 Cell Line | EDJ-KQ195 | Human | 56893 | Details Get a Quote |
| UBQLN4 Knockout A-549 Cell Line | EDJ-KQ25949 | Human | 56893 | Details Get a Quote |
| UBQLN4 Knockout HCT 116 Cell Line | EDJ-KQ25950 | Human | 56893 | Details Get a Quote |
| UBQLN4 Knockout HeLa Cell Line | EDJ-KQ25951 | Human | 56893 | Details Get a Quote |
| UBQLN4 Knockout Flp-In-T-REx-293 Cell Line | EDJ-KZ73 | Human | 56893 | Details Get a Quote |
