E2F3 (E2F Transcription Factor 3)
Overview
flowchart TD
E2F3["E2F3"] -->|"regulates"| endocycle["endocycle"]
E2F3["E2F3"] -->|"drives"| G2_M_transcriptional_program["G2/M transcriptional program"]
E2F3["E2F3"] -->|"activates"| Ms["Ms"]
E2F3["E2F3"] -->|"regulates"| Als["Als"]
E2F3["E2F3"] -->|"activates"| E2F7["E2F7"]
E2F3["E2F3"] -->|"activates"| E2F8["E2F8"]
E2F3["E2F3"] -->|"activates"| E2F1["E2F1"]
E2F3["E2F3"] -->|"activates"| E2F2["E2F2"]
E2F3["E2F3"] -->|"regulates"| CTCF["CTCF"]
E2F3["E2F3"] -->|"regulates"| Rb["Rb"]
E2F3["E2F3"] -->|"regulates"| Cell_Cycle["Cell Cycle"]
E2F3["E2F3"] -->|"activates"| AND["AND"]
E2F3["E2F3"] -->|"regulates"| T_Cell["T Cell"]
E2F3["E2F3"] -->|"regulates"| Neurogenesis["Neurogenesis"]
style E2F3 fill:#4fc3f7,stroke:#333,color:#000
E2F3 (E2F Transcription Factor 3) is a critical member of the E2F family of transcription factors that regulate gene expression essential for cell cycle progression, DNA replication, and cellular proliferation["@dyson2018"][@attwooll2004]. Located on chromosome 6p22, E2F3 functions as both a transcriptional activator and repressor, depending on its binding partners and cellular context["@chen2009"]. Beyond its well-established role in cell cycle regulation, E2F3 has emerged as a significant factor in neuronal development, synaptic plasticity, and neurodegeneration.
<div class="infobox infobox-gene">
...E2F3 (E2F Transcription Factor 3)
Overview
Mermaid diagram (expand to render)
E2F3 (E2F Transcription Factor 3) is a critical member of the E2F family of transcription factors that regulate gene expression essential for cell cycle progression, DNA replication, and cellular proliferation["@dyson2018"][@attwooll2004]. Located on chromosome 6p22, E2F3 functions as both a transcriptional activator and repressor, depending on its binding partners and cellular context["@chen2009"]. Beyond its well-established role in cell cycle regulation, E2F3 has emerged as a significant factor in neuronal development, synaptic plasticity, and neurodegeneration.
<div class="infobox infobox-gene">
| Property | Value |
|----------|-------|
| Gene Symbol | E2F3 |
| Full Name | E2F Transcription Factor 3 |
| Chromosomal Location | 6p22.1 |
| NCBI Gene ID | 1871 |
| OMIM ID | 600427 |
| Ensembl ID | ENSG00000112242 |
| UniProt ID | O00716 |
| Encoded Protein | E2F transcription factor 3 (389 aa) |
| Protein Family | E2F family of transcription factors |
| Associated Diseases | Retinoblastoma, cancer, Alzheimer's disease, Parkinson's disease |
</div>
Function
Cell Cycle Regulation
E2F3 is a key regulator of the G1/S transition in the cell cycle[@dyson2018]. It functions as part of a complex with retinoblastoma protein (pRb):
- In its active form, E2F3 binds to pRb and represses transcription of S-phase genes
- Upon phosphorylation by cyclin-dependent kinases, pRb releases E2F3
- Free E2F3 then activates genes required for DNA replication and cell cycle progression[@attwooll2004]
The E2F family consists of multiple members (E2F1-E2F8) with distinct but overlapping functions. E2F3, particularly E2F3a and E2F3b isoforms, plays essential roles in embryonic development and tissue homeostasis[@chen2009].
Transcriptional Targets
E2F3 regulates numerous genes involved in:
- DNA replication: DHFR, DNA polymerase α, PCNA
- Cell cycle: Cyclins (CYCE, CYCA), CDKs
- [Apoptosis](/entities/apoptosis): P53, BCL2 family members
- Metabolism: Mitochondrial genes, glycolytic enzymes
Role in Neurodegeneration
Alzheimer's Disease
E2F3 has been implicated in Alzheimer's disease pathogenesis through several mechanisms[@yang2013]:
Cell Cycle Re-entry Hypothesis: Post-mitotic [neurons](/entities/neurons) in Alzheimer's disease abnormally re-enter the cell cycle, leading to DNA replication stress and neuronal death. E2F3 dysregulation contributes to this pathological process:
- Elevated E2F3 activity has been observed in AD brain tissue
- Aberrant cell cycle activation leads to [tau](/proteins/tau) hyperphosphorylation
- E2F3-mediated transcription promotes amyloidogenic [APP](/entities/app-protein) processing
Synaptic Dysfunction: E2F3 regulates genes critical for synaptic function:
- Synaptic vesicle proteins
- Neurotransmitter receptors
- Dendritic spine morphology
Parkinson's Disease
In Parkinson's disease, E2F3 may play roles in[@hglinger2007]:
- Dopaminergic neuron survival: E2F3 regulates anti-apoptotic genes important for dopaminergic neuron viability
- [α-Synuclein](/proteins/alpha-synuclein) expression: E2F binding sites exist in the α-synuclein gene promoter, suggesting transcriptional regulation
- Mitochondrial dysfunction: E2F3 regulates mitochondrial biogenesis genes
Cell Cycle Dysregulation in Neurodegeneration
The cell cycle dysregulation hypothesis of neurodegeneration proposes that neurons attempt to re-enter the cell cycle but fail to complete division, leading to apoptotic death[@yang2013]. E2F3 is central to this process:
Initiation: Stress signals trigger cyclin D expression
Activation: CDK4/6 phosphorylates pRb
Release: E2F3 is liberated from pRb inhibition
Transcription: E2F3 activates S-phase genes
Death: Failed cell cycle leads to apoptosisExpression Pattern
E2F3 is expressed in various brain regions:
- Cerebral [cortex](/brain-regions/cortex): Pyramidal neurons, interneurons
- [Hippocampus](/brain-regions/hippocampus): CA1-CA3 pyramidal cells, dentate gyrus granule cells
- Substantia nigra: Dopaminergic neurons
- Cerebellum: Purkinje cells, granule cells
During development, E2F3 expression is high in proliferating neural progenitor cells. In adult brain, E2F3 expression is maintained at lower levels in mature neurons where it continues to regulate synaptic plasticity genes.
Therapeutic Implications
Understanding E2F3's role in neurodegeneration opens therapeutic avenues:
- Cell cycle modulators: Compounds that prevent aberrant E2F3 activation
- pRb pathway enhancers: Strengthening pRb-E2F3 interaction
- Targeted gene therapy: Modulating E2F3 expression in affected neurons
Interactions
E2F3 interacts with several key proteins:
- pRb (RB1): Primary binding partner, transcriptional repressor[@attwooll2004]
- p107 (RBL1): Alternative pocket protein
- p130 (RBL2): Cell cycle-dependent interaction
- Cyclin A: Regulatory interaction
- CDK2: Phosphorylation target
- p300/CBP: Histone acetyltransferase coactivators
See Also
- [Cell cycle dysregulation](/mechanisms/cell-cycle-dysfunction)
- [Alzheimer's disease](/diseases/alzheimers-disease)
- [Parkinson's disease](/diseases/parkinsons-disease)
- [pRb tumor suppressor](/entities/rb1-gene)
- [E2F transcription factors](/entities/e2f-family)
External Links
- [Ensembl: ENSG00000112242](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000112242)
- [NCBI Gene: E2F3](https://www.ncbi.nlm.nih.gov/gene/1871)
- [UniProt: O00716](https://www.uniprot.org/uniprot/O00716)
- [GeneCards: E2F3](https://www.genecards.org/cgi-bin/carddisp.pl?gene=E2F3)
References
Unknown, Wikipedia contributors. E2F3. Wikipedia (n.d.)
[Dyson NJ, RB1: a prototype tumor suppressor and its biology (2018)](https://pubmed.ncbi.nlm.nih.gov/30547185/)
[Attwooll C, Lazzerini Denchi E, Helin K, The E2F family: specific functions and overlapping interests (2004)](https://pubmed.ncbi.nlm.nih.gov/15538360/)
[Chen HZ, Tsai SY, Leone G, Emerging roles of E2Fs in cancer: an exit from cell cycle control (2009)](https://pubmed.ncbi.nlm.nih.gov/19851314/)
[Yang Y, Mufson EJ, Herrup K, Neuronal cell death is preceded by cell cycle re-entry: a historical perspective (2013)](https://pubmed.ncbi.nlm.nih.gov/24267926/)
[Höglinger GU, Breunig JJ, Depboylu C, et al, The pRb/E2F cell-cycle pathway mediates cell death in Parkinson's disease (2007)](https://pubmed.ncbi.nlm.nih.gov/17360685/)Pathway Diagram
The following diagram shows the key molecular relationships involving E2F3 Gene discovered through SciDEX knowledge graph analysis:
Mermaid diagram (expand to render)