CDC25B Gene
<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">cdc25b</th>
</tr>
<tr>
<td class="label">CDK</td>
<td>Cyclin Partner</td>
</tr>
<tr>
<td class="label">CDK1</td>
<td>Cyclin B1</td>
</tr>
<tr>
<td class="label">CDK2</td>
<td>Cyclin E</td>
</tr>
<tr>
<td class="label">CDK2</td>
<td>Cyclin A</td>
</tr>
<tr>
<td class="label">CDK1</td>
<td>Cyclin A</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/cancer" style="color:#ef9a9a">Cancer</a>, <a href="/wiki/ms" style="color:#ef9a9a">Ms</a>, <a href="/wiki/tumor" style="color:#ef9a9a">Tumor</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">19 edges</a></td>
</tr>
</table>
Overview
CDC25B (Cell Division Cycle 25B) is a dual-specificity protein phosphatase that plays a critical role in regulating cell cycle progression by removing inhibitory phosphates from cyclin-dependent kinases (CDKs)[@cdc2021]. As a key activator of CDK1 and CDK2, CDC25B drives cells through the G1/S and G2/M transitions, making it essential for proper cell division and genomic integrity. Intriguingly, CDC25B has also been implicated in neurodegenerative processes, where aberrant cell cycle re-entry appears to contribute to neuronal dysfunction and death in conditions such as Alzheimer's disease and Parkinson's disease[@cdcb2022][@cell2023].
...CDC25B Gene
<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">cdc25b</th>
</tr>
<tr>
<td class="label">CDK</td>
<td>Cyclin Partner</td>
</tr>
<tr>
<td class="label">CDK1</td>
<td>Cyclin B1</td>
</tr>
<tr>
<td class="label">CDK2</td>
<td>Cyclin E</td>
</tr>
<tr>
<td class="label">CDK2</td>
<td>Cyclin A</td>
</tr>
<tr>
<td class="label">CDK1</td>
<td>Cyclin A</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/cancer" style="color:#ef9a9a">Cancer</a>, <a href="/wiki/ms" style="color:#ef9a9a">Ms</a>, <a href="/wiki/tumor" style="color:#ef9a9a">Tumor</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">19 edges</a></td>
</tr>
</table>
Overview
CDC25B (Cell Division Cycle 25B) is a dual-specificity protein phosphatase that plays a critical role in regulating cell cycle progression by removing inhibitory phosphates from cyclin-dependent kinases (CDKs)[@cdc2021]. As a key activator of CDK1 and CDK2, CDC25B drives cells through the G1/S and G2/M transitions, making it essential for proper cell division and genomic integrity. Intriguingly, CDC25B has also been implicated in neurodegenerative processes, where aberrant cell cycle re-entry appears to contribute to neuronal dysfunction and death in conditions such as Alzheimer's disease and Parkinson's disease[@cdcb2022][@cell2023].
The CDC25 family consists of three mammalian isoforms (CDC25A, CDC25B, and CDC25C) that exhibit tissue-specific expression and redundant yet distinct functions. While CDC25A primarily regulates G1/S transition, CDC25B and CDC25C are critical for G2/M progression and mitotic entry[@kristjansdottir2004].
Gene Structure and Expression
The human CDC25B gene is located on chromosome 20p13 and encodes a protein of approximately 647 amino acids with a molecular weight of around 72 kDa. The gene contains multiple exons and gives rise to at least two splice variants with different tissue distributions.
Tissue Distribution
CDC25B exhibits a tissue-specific expression pattern:
- Proliferating cells: High expression in dividing cells
- Brain: Low expression in normal adult brain, upregulated in disease states
- Testis: High expression in spermatogenesis
- Embryonic tissues: Widespread expression during development
Cellular Localization
CDC25B shuttles between cellular compartments:
- Cytoplasmic localization: Inactive state during interphase
- Nuclear translocation: Activation during G2/M transition
- Centrosome association: Important for mitotic spindle function
Protein Function and Mechanism
Catalytic Activity
CDC25B is a dual-specificity phosphatase that removes phosphate groups from:
Threonine residues: e.g., T14 and T15 on CDK1
Tyrosine residues: e.g., Y15 on CDK1
Serine residues: e.g., S287 on CDK2This removal activates the CDK/cyclin complexes, allowing them to phosphorylate downstream substrates and drive cell cycle progression[@arellano2005].
Cell Cycle Regulation
CDC25B functions at multiple cell cycle checkpoints:
- G1/S transition: Activation of CDK2/cyclin E and CDK2/cyclin A
- G2/M transition: Activation of CDK1/cyclin B (the mitotic promoting factor)
- Centrosome maturation: Regulation of CDK1/cyclin B at centrosomes
- Mitotic entry: Final activation of CDK1/cyclin B for mitotic onset
Regulation Mechanisms
CDC25B activity is tightly controlled through multiple mechanisms:
Phosphorylation: At least 10 serine/threonine sites regulate activity
Proteasomal degradation: Ubiquitin-mediated turnover
Subcellular localization: Nuclear import/export controls
Protein-protein interactions: Binding partners modulate functionRole in Neurodegeneration
Alzheimer's Disease
CDC25B has been implicated in Alzheimer's disease through several mechanisms[@yang2005]:
Cell cycle dysregulation: Post-mitotic neurons in AD brains re-enter the cell cycle, expressing cell cycle proteins including CDC25B
Tau pathology: CDC25B-mediated activation of CDKs may contribute to tau hyperphosphorylation
Neuronal vulnerability: Aberrant activation may lead to neuronal dysfunction or death
Amyloid-beta effects: Aβ may trigger cell cycle re-entry pathways involving CDC25BThe cell cycle hypothesis of AD proposes that neuronal dysfunction stems from inappropriate attempts to re-enter the cell cycle, with CDC25B playing a central role in this process[@arendt2010].
Parkinson's Disease
In Parkinson's disease, CDC25B may be involved through:
- Dopaminergic neuron survival: Altered expression in affected brain regions
- Alpha-synuclein toxicity: Possible interactions with cell cycle pathways
- Mitochondrial dysfunction: Links to energy metabolism and cell cycle control
Other Neurodegenerative Conditions
CDC25B dysregulation has been reported in:
- Huntington's disease: Cell cycle abnormalities
- Amyotrophic lateral sclerosis (ALS): Motor neuron vulnerability
- Multiple sclerosis: Possibly in demyelination/remyelination
Clinical Significance
Cancer
CDC25B is frequently overexpressed in various cancers:
- Prognostic marker: High expression correlates with poor outcomes
- Therapeutic target: Several CDC25 inhibitors in development
- Resistance mechanisms: Linked to chemotherapeutic resistance
Neurological Disease
While the role in neurodegeneration is still being characterized:
- Biomarker potential: May serve as disease indicator
- Therapeutic target: Modulating activity may protect neurons
- Diagnostic applications: Detection in CSF or tissue samples
Therapeutic Implications
Inhibitors
CDC25 phosphatase inhibitors have been developed as:
Anticancer agents: Targeting rapidly dividing tumor cells
Neuroprotective agents: Potentially protecting neurons from aberrant cell cycle activation
Combination therapies: With other cell cycle or cytotoxic agentsChallenges
- Selectivity: Achieving specificity among CDC25 isoforms
- Toxicity: Side effects from disrupting normal cell division
- Delivery: Brain penetration for neurological applications
Signaling Pathways
Mermaid diagram (expand to render)
See Also
- [Alzheimer's Disease](/diseases/alzheimers-disease)
- [Parkinson's Disease](/diseases/parkinsons-disease)
- [Cell Cycle Dysregulation](/mechanisms/cell-cycle-dysregulation-neurodegeneration)
- [CDK Proteins](/proteins/cyclin-dependent-kinases)
- [DNA Damage Response](/mechanisms/dna-damage-response)
References
[Kristjansdottir & Rudolph, CDC25 phosphatases and their role in cell cycle regulation (2004)](https://pubmed.ncbi.nlm.nih.gov/15106563/)
[Yang & Herrup, Cell division in neurons: a non-apoptotic form of cell death (2005)](https://pubmed.ncbi.nlm.nih.gov/15997477/)
[CDC25 phosphatases in cell cycle control (2021)](https://doi.org/10.1016/j.tcb.2021.02.005)
[CDC25B in neuronal development (2022)](https://doi.org/10.1007/s12035-021-02567-6)
[Cell cycle dysregulation in Alzheimer's disease (2023)](https://doi.org/10.1007/s12035-023-03123-5)
[Cyclin-dependent kinase regulation in neurodegeneration (2021)](https://doi.org/10.1007/s12035-020-02245-8)
[Targeting CDC25 phosphatases in cancer and disease (2022)](https://doi.org/10.1038/s41573-022-00412-6)
[Duccini et al., CDC25B in cancer and neurodegeneration: a dual role (2018)](https://pubmed.ncbi.nlm.nih.gov/29106447/)
[Arellano & Moreno, Regulation of CDK/cyclin complexes during the cell cycle (2005)](https://pubmed.ncbi.nlm.nih.gov/15743679/)
[Boutros et al., CDC25 phosphatases at the interface of cell cycle and DNA damage response (2007)](https://pubmed.ncbi.nlm.nih.gov/17622196/)
[Gonzalez et al., CDC25 phosphatases as therapeutic targets in neurological disease (2018)](https://pubmed.ncbi.nlm.nih.gov/29368125/)
[Arrendale et al., Phosphatase inhibition and pyruvate analogue reduced tau toxicity (2012)](https://pubmed.ncbi.nlm.nih.gov/22389491/)
[Yu et al., CDC25A and CDC25B in brain development and disease (2019)](https://pubmed.ncbi.nlm.nih.gov/31189456/)
[Karlsson et al., The mitotic phosphatase CDC25B is a potential target for cancer therapy (2004)](https://pubmed.ncbi.nlm.nih.gov/15041993/)
[Gordon et al., Cell cycle dysregulation in neurodegenerative disorders (2012)](https://pubmed.ncbi.nlm.nih.gov/22821226/)
[Lee et al., CDC25C phosphorylation by CDK1 contributes to tau pathology (2009)](https://pubmed.ncbi.nlm.nih.gov/18692279/)
[Kelley & Naidoo, Cell cycle proteins as markers of aging and neurodegeneration (2010)](https://pubmed.ncbi.nlm.nih.gov/20434425/)
[Arendt et al., Neuronal cycle activity and pathological cell cycle re-entry in Alzheimer's disease (2010)](https://pubmed.ncbi.nlm.nih.gov/20049474/)
[Moh et al., Cell cycle proteins in brain: markers of neuronal dysfunction and pathology (2011)](https://pubmed.ncbi.nlm.nih.gov/21259052/)
[Zhao et al., CDC25B promotes cell proliferation and survival in gliomas (2016)](https://pubmed.ncbi.nlm.nih.gov/26759341/)External Links
- [NCBI Gene: CDC25B](https://www.ncbi.nlm.nih.gov/gene/994)
- [Ensembl: ENSG00000101290](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000101290)
- [UniProt: P30305](https://www.uniprot.org/uniprot/P30305)
- [OMIM: 116947](https://www.omim.org/entry/116947)
Additional Mechanisms
Checkpoint Regulation
CDC25B integrates multiple checkpoint signals:
DNA damage checkpoints: ATM/ATR-mediated inhibition
Spindle assembly checkpoint: Regulation of mitotic entry
Replication stress response: Coordination with DNA repairApoptosis Relationship
The relationship between CDC25B and apoptosis is complex:
- Pro-survival: Normal cell cycle progression prevents apoptosis
- Pro-apoptotic: Overactivation can trigger cell death
- Context-dependent: Effects vary with cell type and conditions
CDK Substrate Specificity
CDC25B activates multiple CDK/cyclin complexes:
Research Directions
Biomarker Development
CDC25B as a potential biomarker:
- Diagnostic: Detection in CSF or blood
- Prognostic: Disease progression indicator
- Therapeutic response: Treatment monitoring
Therapeutic Strategies
Direct inhibitors: Small molecules targeting catalytic site
Indirect approaches: Modulating upstream regulators
Combination therapy: With other neuroprotective agentsAnimal Models
- Knockout mice: Viable with subtle phenotypes
- Transgenic models: Overexpression studies
- Conditional knockouts: Tissue-specific deletion
Summary
CDC25B is a critical cell cycle phosphatase with dual roles in normal cellular proliferation and pathological processes in neurodegenerative diseases. Its ability to activate CDKs makes it essential for proper cell division, while its dysregulation contributes to aberrant cell cycle re-entry in neurons undergoing degeneration. Understanding the precise mechanisms by which CDC25B influences neurodegeneration may lead to novel therapeutic strategies for conditions such as Alzheimer's disease and Parkinson's disease.
Pathway Diagram
The following diagram shows the key molecular relationships involving CDC25B Gene discovered through SciDEX knowledge graph analysis:
Mermaid diagram (expand to render)