HDAC2 — Histone Deacetylase 2
Pathway Diagram
flowchart TD
HDAC2["HDAC2"]
style HDAC2 fill:#006494,stroke:#4fc3f7,stroke-width:3px,color:#e0e0e0
LAPTM4B["LAPTM4B"]
HDAC2 -->|"associated with"| LAPTM4B
Autophagy["Autophagy"]
HDAC2 -->|"regulates"| Autophagy
HDAC2 -->|"binds"| LAPTM4B
Hepatocellular_Carcinoma["Hepatocellular Carcinoma"]
HDAC2 -->|"associated with"| Hepatocellular_Carcinoma
Colorectal_Cancer["Colorectal Cancer"]
HDAC2 -->|"associated with"| Colorectal_Cancer
Cancer["Cancer"]
HDAC2 -->|"associated with"| Cancer
Epigenetic["Epigenetic"]
HDAC2 -->|"regulates"| Epigenetic
Neurodegeneration["Neurodegeneration"]
HDAC2 -->|"regulates"| Neurodegeneration
CI_994["CI-994"]
CI_994 -->|"inhibits"| HDAC2
PLEKHG5["PLEKHG5"]
PLEKHG5 -->|"interacts with"| HDAC2
CANCER["CANCER"]
CANCER -->|"associated with"| HDAC2
style LAPTM4B fill:#1b5e20,stroke:#4fc3f7,color:#e0e0e0
style Autophagy fill:#888,stroke:#4fc3f7,color:#e0e0e0
style Hepatocellular_Carcinoma fill:#ef5350,stroke:#4fc3f7,color:#e0e0e0
style Colorectal_Cancer fill:#ef5350,stroke:#4fc3f7,color:#e0e0e0
style Cancer fill:#ef5350,stroke:#4fc3f7,color:#e0e0e0
style Epigenetic fill:#5d4400,stroke:#4fc3f7,color:#e0e0e0
style Neurodegeneration fill:#ef5350,stroke:#4fc3f7,color:#e0e0e0
style CI_994 fill:#006494,stroke:#4fc3f7,color:#e0e0e0
style PLEKHG5 fill:#1b5e20,stroke:#4fc3f7,color:#e0e0e0
style CANCER fill:#1b5e20,stroke:#4fc3f7,color:#e0e0e0
Introduction
...HDAC2 — Histone Deacetylase 2
Pathway Diagram
Mermaid diagram (expand to render)
Introduction
Hdac2 Gene is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
<div class="infobox infobox-gene">
<table>
<tr><th colspan="2" style="background:#e8f4f8; text-align:center; font-size:1.1em;">Histone Deacetylase 2</th></tr>
<tr><td><strong>Gene Symbol</strong></td><td>HDAC2</td></tr>
<tr><td><strong>Full Name</strong></td><td>Histone Deacetylase 2</td></tr>
<tr><td><strong>Chromosome</strong></td><td>6q21</td></tr>
<tr><td><strong>NCBI Gene ID</strong></td><td>[3066](https://www.ncbi.nlm.nih.gov/gene/3066)</td></tr>
<tr><td><strong>OMIM</strong></td><td>605185</td></tr>
<tr><td><strong>Ensembl ID</strong></td><td>ENSG00000196591</td></tr>
<tr><td><strong>UniProt ID</strong></td><td>[Q92769](https://www.uniprot.org/uniprot/Q92769)</td></tr>
<tr><td><strong>Associated Diseases</strong></td><td>Alzheimer's Disease, Huntington's Disease, Rett Syndrome</td></tr>
</table>
</div>
Overview
HDAC2 ([Histone Deacetylase](/entities/hdac-enzymes) 2) is a Class I histone deacetylase that plays crucial roles in epigenetic regulation of gene expression, particularly in the brain[@grff2012]. It is a key player in chromatin remodeling and transcriptional repression, with critical functions in learning, memory, and synaptic plasticity.
HDAC2 is widely studied in the context of neurodegenerative diseases, where its dysregulation contributes to transcriptional deficits observed in Alzheimer's disease, Huntington's disease, and Rett syndrome[@jia2012]. The enzyme is part of the CoREST and Sin3A repressor complexes, targeting specific gene promoters for histone deacetylation.
Function
HDAC2 encodes histone deacetylase 2, a class I histone deacetylase that regulates gene expression through chromatin remodeling. HDAC2 is highly expressed in [neurons](/entities/neurons) and plays critical roles in synaptic plasticity, memory formation, and transcriptional regulation. It is part of the CoREST and Sin3A repressor complexes.
Expression
High expression in brain, particularly in [hippocampus](/brain-regions/hippocampus), cerebral [cortex](/brain-regions/cortex), and cerebellum. Expressed in neurons and some glial cells.
Disease Associations
| Disease | Mechanism | References |
|---------|-----------|------------|
| Alzheimer's Disease | HDAC2 levels increase in AD brains, repressing memory-related genes | [@grff2012] |
| Huntington's Disease | HDAC2 regulates mutant [huntingtin](/proteins/huntingtin-protein) expression | [@jia2012] |
| Rett Syndrome | HDAC2 dysregulation contributes to neurodevelopmental defects | [@vogel2019] |
Therapeutic Targeting
HDAC2 inhibitors are being explored for:
- Cognitive enhancement in AD
- HDAC2-selective inhibitors to avoid side effects
- Epigenetic therapy for neurodegeneration
Background
The study of Hdac2 Gene 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.
Molecular Mechanisms
HDAC2 (Histone Deacetylase 2) is a Class I histone deacetylase that removes acetyl groups from lysine residues on histone proteins, leading to chromatin condensation and transcriptional repression. HDAC2 is part of the Sin3, NuRD, and CoREST co-repressor complexes, which are recruited by sequence-specific transcription factors to regulate gene expression.
Beyond histones, HDAC2 also deacetylates non-histone proteins, including transcription factors (e.g., p53, STAT3), signaling molecules, and structural proteins. This broad substrate specificity allows HDAC2 to regulate diverse cellular processes beyond transcription.
Disease Associations
Alzheimer's Disease: HDAC2 expression is elevated in AD brains, particularly in regions affected by neurodegeneration. Elevated HDAC2 activity leads to transcriptional repression of genes involved in synaptic plasticity, memory formation, and neuronal survival. HDAC2 inhibitors have shown promise in preclinical AD models.
Parkinson's Disease: HDAC2 may regulate genes involved in dopaminergic neuron survival and function. HDAC2 inhibitors have shown neuroprotective effects in PD models.
Huntington's Disease: HDAC2 contributes to transcriptional dysfunction in HD by repressing genes important for neuronal function. HDAC inhibitors are being explored as potential therapies.
ALS: HDAC2 expression and activity are altered in ALS, contributing to motor neuron dysfunction. HDAC inhibitors have shown some efficacy in preclinical models.
Therapeutic Implications
HDAC2 inhibitors (e.g., vorinostat, entinostat) are being investigated for neurodegenerative diseases. These compounds can reverse transcriptional deficits and provide neuroprotection. However, systemic side effects limit clinical applications.
Research Directions
Research focuses on developing brain-penetrant, isoform-selective HDAC2 inhibitors with improved safety profiles. Understanding the specific gene targets of HDAC2 in different disease contexts is a priority.
Epigenetic Regulation in Neurodegeneration
The field of epigenetics has emerged as a key area in understanding neurodegenerative diseases. DNA methylation patterns are dynamically regulated in the brain, and alterations in these patterns are increasingly recognized as contributors to disease pathogenesis.
Animal Models
Transgenic mouse models lacking DNMT3A in neural progenitor cells show altered brain development and behavior. These models are used to study the role of DNA methylation in neurodegeneration.
Biomarker Potential
DNA methylation marks in peripheral tissues (blood, CSF) are being investigated as potential biomarkers for neurodegenerative disease diagnosis and progression.
Clinical Trials
Several clinical trials are exploring epigenetic therapies, including HDAC inhibitors and DNMT inhibitors, for neurodegenerative diseases. Early-phase trials have shown some promise.
See Also
- [HDAC2 Protein](/proteins/hdac2-protein)
- HDAC1 Gene
- HDAC4 Gene
- HDAC6 Gene
- Histone Deacetylases
- [Epigenetics in Neurodegeneration](/mechanisms/epigenetic-regulation-neurodegeneration)
- [Alzheimer's Disease](/diseases/alzheimers-disease)
- [Huntington's Disease](/diseases/huntingtons-disease)
- [Rett Syndrome](/diseases/rett-syndrome)
External Links
- [NCBI Gene: HDAC2](https://www.ncbi.nlm.nih.gov/gene/3066)
- [UniProt: HDAC2](https://www.uniprot.org/uniprot/Q92769)
- [Ensembl: HDAC2](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000196591)
- [GeneCards: HDAC2](https://www.genecards.org/cgi-bin/carddisp.pl?gene=HDAC2)
References
Gräff, J., et al, (2012) (2012)
Jia, H., et al, (2012) (2012)
Vogel, S. G., et al., (2019). HDAC2 in neurodevelopment (2019)Pathway Diagram
The following diagram shows the key molecular relationships involving HDAC2 Gene discovered through SciDEX knowledge graph analysis:
Mermaid diagram (expand to render)