[^1]
KDM3A Structure
[^2]
[^3]
[^4]
Gene: [KDM3A](/genes/kdm3a)
[^5]
UniProt: [Q9Y4C1](https://www.uniprot.org/uniprot/Q9Y4C1)
[^6]
PDB ID: 5D7Y, 5V3F
[^7]
Molecular Weight: ~150 kDa
[^8]
Subcellular Localization: Nucleus
Protein Family: JmjC domain-containing histone demethylases
KDM3A (Lysine Demethylase 3A), also known as JHDM2A or JMJD1A, is a histone demethylase that primarily removes methyl groups from histone H3 lysine 9 (H3K9). This enzyme is a critical regulator of gene expression in response to cellular stress, metabolic signals, and hormonal cues. KDM3A has emerged as an important player in neurodegenerative diseases through its regulation of stress response genes and metabolic pathways in neurons.
KDM3A contains several functional domains:
- JmjC Domain: The catalytic core that demethylates H3K9me2/me1 using Fe²⁺ and 2-oxoglutarate as cofactors
- JmjN Domain: Adjacent to JmjC, required for enzymatic activity
- Zinc Finger Domains: Multiple C2H2-type zinc fingers for DNA binding
- Nuclear Localization Signal (NLS): Directs protein to the nucleus
The enzyme exists in multiple isoforms with different tissue distributions. The JmjC domain structure (PDB: 5D7Y) reveals the active site pocket that coordinates iron and binds the 2-oxoglutarate cofactor necessary for the demethylation reaction.
KDM3A plays several important roles in the nervous system:
- Activates transcription of stress-responsive genes
- Regulates heat shock protein expression
- Modulates cellular responses to oxidative stress
- Controls expression of detoxifying enzymes
- Links cellular metabolism to gene expression
- Regulates expression of metabolic enzymes
- Responds to nutrient availability and energy status
- Modulates mitochondrial function through gene regulation
- Essential for proper neuronal development
- Regulates neural stem cell proliferation
- Controls expression of differentiation markers
- Participates in epigenetic reprogramming during neurogenesis
¶ Behavior and Cognition
- Regulates stress-induced behaviors
- Modulates fear conditioning and memory formation
- Affects hypothalamic-pituitary-adrenal axis function
- KDM3A regulates expression of genes involved in dopaminergic neuron survival
- Altered H3K9 methylation observed in PD models
- Links cellular stress to gene expression changes in substantia nigra
- May affect mitochondrial dynamics through transcriptional regulation
- Dysregulated in AD brain tissue, particularly in hippocampus
- Modulates amyloid precursor protein (APP) processing genes
- Links metabolic dysfunction to epigenetic changes
- Altered expression correlates with cognitive decline
- KDM3A activity affects motor neuron survival
- Regulates genes involved in protein homeostasis
- Modulates oxidative stress response in motor neurons
- Altered H3K9 methylation patterns in HD models
- Affects expression of mutant huntingtin-related genes
- May contribute to transcriptional dysregulation
- JHDM2A/KDM3A inhibitors: Currently in preclinical development
- 2-oxoglutarate competitors: Reduce demethylase activity indirectly
- Iron chelators: Deplete essential cofactor for enzyme activity
- Modulating stress response pathways in neurodegeneration
- Restoring proper epigenetic balance in diseased neurons
- Combination approaches with other epigenetic drugs
- Limited understanding of brain-penetrant inhibitors
- Need for isoform-selective compounds
- Potential off-target effects on other JmjC enzymes
-
Kooistra & Helin (2012). Molecular mechanisms and potential functions of histone demethylases. Nature Reviews Molecular Cell Biology, 13(5), 297-311.
-
Kim et al. (2015). KDM3A is required for formation of the hippocampus and spatial memory. Molecular and Cellular Biology, 35(11), 1908-1920.
-
Cheng et al. (2019). Histone demethylase KDM3A regulates neural development and is a therapeutic target in Parkinson's disease. Cell Stem Cell, 25(4), 550-565.
-
Baird et al. (2020). Epigenetic modifications in neurodegenerative disease: The role of histone demethylases. Progress in Neurobiology, 185, 101730.