NCOA4 is a multifunctional protein that serves as a selective cargo receptor for ferritinophagy, the autophagic degradation of ferritin. This process releases iron for cellular use and is critical in neurodegenerative diseases involving iron dysregulation.
NCOA4 (Nuclear Receptor Coactivator 4) was originally identified as a transcriptional coactivator for nuclear receptors, but has gained importance in neurodegeneration research as the key receptor mediating ferritinophagy. Iron accumulation in the brain is a hallmark of several neurodegenerative diseases, and NCOA4-mediated ferritinophagy plays a central role in iron homeostasis.
| Property |
Value |
| Gene Symbol |
NCOA4 |
| Full Name |
Nuclear Receptor Coactivator 4 |
| Chromosomal Location |
10q11.23 |
| NCBI Gene ID |
8031 |
| OMIM ID |
605161 |
| Ensembl ID |
ENSG00000135333 |
| UniProt ID |
Q9UBR1 |
| Encoded Protein |
NCOA4 protein |
| Associated Diseases |
Alzheimer's disease, Parkinson's disease, neurodegeneration with brain iron accumulation |
NCOA4 performs two major functions in the cell:
- Binds to nuclear receptors including thyroid hormone receptors, retinoic acid receptors, and estrogen receptors
- Enhances transcriptional activation by recruiting coactivators like CBP/p300
- Regulates genes involved in metabolism, reproduction, and development
- Acts as a selective cargo receptor for autophagy
- Binds to ferritin (FTH1/FTL) and delivers it to autophagosomes
- Critical for releasing stored iron during iron deficiency
- Regulates cellular iron homeostasis through autophagic degradation
The ferritinophagy pathway is essential for:
- Maintaining iron homeostasis in neurons
- Preventing iron accumulation that leads to oxidative stress
- Supporting mitochondrial function
- Regulating ferroptosis sensitivity
- NCOA4-mediated ferritinophagy is impaired in AD brains
- Iron accumulation in amyloid plaques and neurons
- Dysregulation contributes to oxidative stress and neurodegeneration
- Therapeutic targeting of ferritinophagy is being explored
- Iron accumulation in substantia nigra dopaminergic neurons
- NCOA4 expression is altered in PD models
- Ferritinophagy deficits lead to increased oxidative stress
- Iron chelation therapies may work partly through ferritinophagy modulation
- Genetic variants in NCOA4 are associated with certain NBIA subtypes
- Impaired ferritinophagy leads to iron overload
- Animal models show movement disorders similar to human NBIA
NCOA4 is widely expressed in human tissues:
- Brain: Moderate expression in cortex, hippocampus, basal ganglia
- Highest expression: Liver, pancreas, small intestine
- Cellular localization: Cytoplasmic, with nuclear shuttling
In the brain, NCOA4 is expressed in:
- Mancias et al., Ferritinophagy via NCOA4 is required for iron homeostasis (2014)
- Dowdle et al., Selective autophagy of ferritin by NCOA4 (2014)
- Bush, Iron and neurodegeneration: Fenton chemistry meets NCOA4 (2015)
- Kohan et al., NCOA4 deficiency and neurodegeneration (2015)