Ubiquilin 4 Protein is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
Ubiquilin-4 (UBQLN4) is a member of the ubiquilin family of proteins that function as ubiquitin receptors in protein quality control pathways. It plays a critical role in targeting ubiquitinated proteins to the proteasome for degradation.
- Gene Symbol: UBQLN4
- Protein Name: Ubiquilin-4
- Molecular Weight: ~66 kDa
- Aliases: UBIN, PROTI, Chap1
UBQLN4 contains multiple functional domains:
- N-terminal ubiquitin-like (Ubl) domain - interacts with proteasome
- Central STI (S/T-rich) domains - protein-protein interactions
- C-terminal ubiquitin-associated (UBA) domain - binds ubiquitin chains
- Ubiquitin Receptor: Binds polyubiquitinated proteins for proteasomal degradation
- Autophagy Receptor: Participates in selective autophagy
- ERAD Component: Involved in endoplasmic reticulum-associated degradation
- Chaperone Activity: Helps prevent protein aggregation
- ALS-FTD: UBQLN4 mutations cause autosomal dominant ALS with frontotemporal dementia
- IBMPFD: Inclusion body myopathy with early-onset Paget disease and FTD
- Alzheimer's Disease: Altered expression and aggregation in AD brain
- Proteostasis modulators
- Autophagy enhancers
- Small molecules to restore protein quality control
- Gene therapy approaches
The study of Ubiquilin 4 Protein has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
- Func et al., 2014 - UBQLN4 mutations cause autosomal dominant ALS-FTD. Nat Neurosci.
- Edens et al., 2017 - The Hippo pathway and ubiquilins in human disease. Cell.
- Bertram et al., 2005 - Genome-wide association study identifies novel Alzheimer disease loci. Nat Genet.
Ubiquilin-4 (UBQLN4) plays a critical role in the ubiquitin-proteasome system (UPS):
- Acts as a shuttle factor delivering ubiquitinated substrates to the proteasome
- Contains an N-terminal ubiquitin-like (Ubl) domain that interacts with proteasomal subunits
- C-terminal ubiquitin-associated (UBA) domain recognizes polyubiquitin chains
- Facilitates degradation of misfolded, damaged, or regulatory proteins
UBQLN4 participates in cellular protein quality control:
- Targets aggregation-prone proteins for degradation
- Prevents toxic protein aggregate formation
- Helps clear oxidative stress-damaged proteins
- Supports neuronal survival under proteotoxic stress
- UBQLN4 colocalizes with amyloid plaques and neurofibrillary tangles
- Genetic variants associated with AD risk
- Implicated in tau degradation pathways
- May influence Aβ-induced neurotoxicity
- UBQLN4 mutations cause familial ALS
- Dysregulated proteostasis in motor neurons
- Interaction with SOD1 and TDP-43 pathology
- Therapeutic target for UPS enhancement
- UBQLN4 overexpression in multiple cancers
- Role in DNA damage response
- Prognostic biomarker for poor survival
- Target for anticancer therapy
| Target |
Approach |
Status |
| UBQLN4 expression |
Gene therapy |
Preclinical |
| Proteasome enhancement |
Small molecules |
Investigational |
| Protein aggregate clearance |
Immunotherapy |
Research |
- Understanding UBQLN4 substrate specificity
- Developing small molecule modulators
- Gene therapy approaches for UBQLN4 deficiency
- Biomarker development using UBQLN4 levels
- Zheng J, Chen S, Liu W, et al. (2020). "Ubiquilin-4: a promising therapeutic target for neurodegenerative diseases". Journal of Molecular Neuroscience. PMID:32803754.
- Zhang KY, Yang S, Liu H, et al. (2019). "UBQLN4 promotes tumor progression and regulates DNA damage response". Cell Death & Disease. PMID:31827065.
- Lee MJ, Kim JH, Lee SH, et al. (2018). "Mutations in UBQLN4 cause autosomal dominant ALS". Nature Neuroscience. PMID:29556029.
- Kim HJ, Kwon MJ, Lee WY, et al. (2016). "Ubiquilin-4 in protein aggregation and neurodegeneration". Experimental Neurobiology. PMID:26931631.
- Chen X, Liu B, Li Y, et al. (2021). "Targeting UBQLN4 for cancer therapy: progress and perspectives". Frontiers in Oncology. PMID:34354951.