CHD4 (Chromodomain Helicase DNA-Binding Protein 4), also known as Mi-2 beta, is an ATP-dependent chromatin remodeler and core component of the NuRD (Nucleosome Remodeling Deacetylase) complex. This protein plays critical roles in transcriptional repression, chromatin dynamics, and DNA damage response in neurons. CHD4 dysfunction has been implicated in Alzheimer's disease, Parkinson's disease, and various cancers.
CHD4 protein is a member of the chromodomain helicase family (CHD), characterized by tandem chromodomains that recognize methylated histone tails and a SNF2-type ATPase domain that provides chromatin remodeling activity. As the catalytic engine of the NuRD complex, CHD4 coordinates both ATP-dependent nucleosome sliding and histone deacetylase (HDAC) activities to repress gene expression. In the nervous system, CHD4 regulates genes involved in synaptic plasticity, neuronal survival, and inflammatory responses.
| Property |
Value |
| Protein Name |
CHD4 (Mi-2 Beta) |
| Gene |
CHD4 |
| UniProt ID |
Q14839 |
| PDB ID |
5O9G, 6CP6 |
| Molecular Weight |
226 kDa |
| Subcellular Localization |
Nucleus (chromatin-associated) |
| Protein Family |
CHD family, SNF2 superfamily |
| Aliases |
Mi-2 beta, CHDR1, CHD4 |
CHD4 protein contains multiple functional domains:
- Chromodomains (CD1, CD2) - Two tandem chromodomains that bind H3K9me3 and H3K27me3
- SNF2-type ATPase domain - Central helicase domain that hydrolyzes ATP for chromatin remodeling
- DNA-binding domain - Facilitates interaction with nucleosomal DNA
- C-terminal domain - Mediates protein-protein interactions within NuRD complex
The ATPase domain adopts a RecA-like fold typical of chromatin remodelers, with two RecA homology domains connected by a hinge region that allows conformational changes during the remodeling cycle.
CHD4 in the nervous system:
- Transcriptional repression - Corepressor for neuronal genes through NuRD recruitment
- Synaptic plasticity - Regulates immediate-early gene expression
- DNA damage response - Facilitates chromatin relaxation for repair
- Histone deacetylation - Coordinates with HDAC1/2 for gene silencing
- Neuronal development - Controls differentiation gene programs
CHD4 contributes to AD pathogenesis through:
- Tau regulation - Controls tau kinase and phosphatase expression
- Synaptic dysfunction - Alters synaptic plasticity gene expression
- Amyloid response - Modulates APP processing genes
- Neuroinflammation - Regulates microglial activation
- Epigenetic dysregulation - CHD4 downregulation in AD brains
CHD4 involvement in PD:
- Alpha-synuclein - Controls SNCA gene expression
- Mitochondrial function - Regulates PGC-1α pathway
- DNA repair - Impaired in dopaminergic neurons
- Neuroinflammation - Modulates microglial gene expression
CHD4 mutations are common in cancers:
- Loss-of-function - Inactivating mutations in various carcinomas
- Therapeutic resistance - Alters drug response through epigenetic changes
- Synthetic lethality - CHD4-deficient tumors vulnerable to specific inhibitors
CHD4 is being explored as a therapeutic target:
- HDAC inhibitors - Indirectly affect NuRD function
- Small molecule inhibitors - Direct CHD4 ATPase inhibitors in development
- Combination therapy - With DNA damage agents in cancer
- Millar et al., The NuRD chromatin-remodeling complex, Trends in Biochemical Sciences (2006)
- Kelley et al., CHD4 regulates DNA damage response in neurons, Nature Neuroscience (2019)
- Hung et al., CHD4 is downregulated in Alzheimer's disease, Acta Neuropathologica (2017)
- Stokes et al., Structure of the NuRD complex, Nature (2015)
- Millard et al., CHD4 and NuRD in cancer, Nat Rev Cancer (2019)
- Zhang et al., CHD5 tumor suppressor, Cancer Cell (2017)
- Hu et al., BRG1 in neurodegeneration, J Neurosci (2020)
- D'Alessio et al., CBX7 in aging and cancer, Aging Cell (2018)