Ep300 Protein (P300) is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
EP300 (E1A-associated protein p300) is a transcriptional coactivator and histone acetyltransferase that plays a crucial role in regulating gene expression, cellular differentiation, and neuronal plasticity. p300 is one of the most important transcriptional coactivators in eukaryotes, with the ability to integrate signals from numerous transcription factors and chromatin remodeling complexes. It is essential for normal development, and mutations cause Rubinstein-Taybi syndrome in humans[^1].
| Property |
Value |
| Gene Symbol |
EP300 |
| Protein Name |
Histone Acetyltransferase p300 |
| UniProt ID |
Q09472 |
| Molecular Weight |
~264 kDa (2414 amino acids) |
| Protein Family |
HAT family (KAT3B) |
| Expression |
Ubiquitous, high in brain, testis |
| Chromosomal Location |
22q13.2 |
The p300 protein contains multiple functional domains:
- Contains binding sites for numerous transcription factors
- Includes nuclear receptor interaction domain (NRID)
- Bromo domain for acetyl-lysine recognition
¶ Histone Acetyltransferase (HAT) Domain
- Amino acids 1195-1673
- Catalyzes histone H3/H4 acetylation
- Central to coactivator function
¶ Interacting Domains
- CH1/CH3: Transcriptional activator binding
- CH2: HAT domain support
- KIX: CREB and other transcription factor binding
- RING: E3 ubiquitin ligase activity
- ZZ: Zinc finger domain
p300 is a histone acetyltransferase (HAT) that[^2]:
- Acetylates histone H3 (lysines 9, 14, 18, 27) and H4 (lysines 5, 8, 12, 16, 20)
- Opens chromatin structure, enabling transcription
- Creates binding sites for bromodomain-containing proteins
- Regulates nucleosome assembly
p300 serves as a molecular bridge:
| Transcription Factor |
Interaction |
Functional Outcome |
| CREB |
KIX domain |
Memory, circadian rhythm |
| NF-κB |
CH1/CH3 domains |
Inflammation, survival |
| p53 |
Multiple domains |
Cell cycle, apoptosis |
| STATs |
CH1 domain |
Cytokine signaling |
| Nuclear receptors |
NRID |
Hormone response |
| MyoD |
CH3 domain |
Muscle differentiation |
p300 recruits and coordinates:
- SWI/SNF complexes
- Mediator complex
- TFIID and other basal transcription factors
- Histone methyltransferases
p300 dysfunction plays a significant role in AD[^3]:
- Reduced HAT activity: p300 activity decreased in AD brain
- Histone acetylation deficits: Global H3/H4 acetylation reduced
- Transcriptional dysregulation: Memory-related gene expression altered
- Amyloid-β effects: Aβ inhibits p300 activity
- Therapeutic potential: HDAC inhibitors boost p300/CBP function
In PD, p300 is implicated through[^4]:
- Dopaminergic signaling: p300 regulates tyrosine hydroxylase
- α-Synuclein toxicity: p300 modulates inclusion formation
- Neuroinflammation: NF-κB-p300 pathway in microglial activation
- Mitochondrial function: PGC-1α coactivation affected
p300 in HD[^5]:
- Transcriptional dysfunction: p300 activity altered by mutant huntingtin
- HAT inhibition: Reduced histone acetylation in HD models
- Therapeutic target: p300/CBP modulators in development
In ALS:
- Transcription regulation: p300 affects ALS-related genes
- RNA metabolism: Interactions with TDP-43 pathology
- Therapeutic approaches: HDAC inhibitors being investigated
| Approach |
Mechanism |
Status |
| HAT activators |
Increase histone acetylation |
Research |
| HDAC inhibitors |
Indirect p300 activation |
Clinical trials |
| CBP/p300-specific |
Selective modulation |
Preclinical |
| Gene therapy |
Deliver functional p300 |
Experimental |
- HDAC inhibitors (valproic acid, sodium butyrate): Increase histone acetylation by inhibiting deacetylases
- HAT activators: Direct activation of p300/CBP
- Small molecule modulators: Selective targeting
- Lifestyle interventions: Exercise and diet affect p300
Ep300 knockout mice are embryonic lethal, demonstrating essential role in development[^6].
Neuron-specific Ep300 knockout shows:
- Impaired learning and memory
- Reduced synaptic plasticity
- Altered gene expression
- Social behavior deficits
p300 overexpression enhances memory in mice, supporting therapeutic potential.
- Selective modulators: Developing p300-specific drugs
- Biomarkers: p300 activity as therapeutic biomarker
- Combination therapy: HDAC inhibitors with other treatments
- Gene therapy: Viral delivery of p300
- Roth SY, et al. (2001). "Histone acetyltransferases." Annu Rev Biochem. PMID:11395403
- Wang F, et al. (2008). "p300/CBP in transcription and epigenetics." J Mol Biol. PMID:18662542
- Maragno G, et al. (2011). "p300 in Alzheimer's disease." J Alzheimers Dis. PMID:21971461
- Qiu Z, et al. (2020). "p300 and Parkinson's disease." Mol Neurobiol. PMID:31784973
- Levenson JM, et al. (2004). "p300 and memory." Learn Mem. PMID:15536849
The study of Ep300 Protein (P300) 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.
- PMID:11395403 - Histone acetyltransferases
- PMID:18662542 - p300/CBP in transcription
- PMID:21971461 - p300 in Alzheimer's disease
- PMID:31784973 - p300 in Parkinson's disease
- PMID:15536849 - p300 and memory
- PMID:10866608 - Ep300 knockout mice