PDE4C — Phosphodiesterase 4C

PDE4C — Phosphodiesterase 4C

Introduction

Pde4C — Phosphodiesterase 4C 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"> [@menniti2006]
<table> [@pde2003]
<tr><th colspan="2" style="background:#e8f4f8; text-align:center; font-size:1.1em;">Phosphodiesterase 4C</th></tr> [@pde2015]
<tr><td><strong>Gene Symbol</strong></td><td>PDE4C</td></tr> [@camp2017]
<tr><td><strong>Full Name</strong></td><td>Phosphodiesterase 4C</td></tr> [@rolipram2011]
<tr><td><strong>Chromosome</strong></td><td>19q13.12</td></tr> [@pde2014]
<tr><td><strong>NCBI Gene ID</strong></td><td>[5144](https://www.ncbi.nlm.nih.gov/gene/5144)</td></tr> [@pdec2010]
<tr><td><strong>OMIM</strong></td><td>610172</td></tr>
<tr><td><strong>Ensembl ID</strong></td><td>ENSG00000074527</td></tr>
<tr><td><strong>UniProt ID</strong></td><td>[Q08431](https://www.uniprot.org/uniprot/Q08431)</td></tr>
<tr><td><strong>Associated Diseases</strong></td><td>[Alzheimer's Disease](/diseases/alzheimers-disease), [Parkinson's Disease](/diseases/parkinsons-disease), Asthma, COPD</td></tr>
</table>
</div>

Overview

...

PDE4C — Phosphodiesterase 4C

Introduction

Pde4C — Phosphodiesterase 4C 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"> [@menniti2006]
<table> [@pde2003]
<tr><th colspan="2" style="background:#e8f4f8; text-align:center; font-size:1.1em;">Phosphodiesterase 4C</th></tr> [@pde2015]
<tr><td><strong>Gene Symbol</strong></td><td>PDE4C</td></tr> [@camp2017]
<tr><td><strong>Full Name</strong></td><td>Phosphodiesterase 4C</td></tr> [@rolipram2011]
<tr><td><strong>Chromosome</strong></td><td>19q13.12</td></tr> [@pde2014]
<tr><td><strong>NCBI Gene ID</strong></td><td>[5144](https://www.ncbi.nlm.nih.gov/gene/5144)</td></tr> [@pdec2010]
<tr><td><strong>OMIM</strong></td><td>610172</td></tr>
<tr><td><strong>Ensembl ID</strong></td><td>ENSG00000074527</td></tr>
<tr><td><strong>UniProt ID</strong></td><td>[Q08431](https://www.uniprot.org/uniprot/Q08431)</td></tr>
<tr><td><strong>Associated Diseases</strong></td><td>[Alzheimer's Disease](/diseases/alzheimers-disease), [Parkinson's Disease](/diseases/parkinsons-disease), Asthma, COPD</td></tr>
</table>
</div>

Overview

PDE4C (Phosphodiesterase 4C) is a cAMP-specific phosphodiesterase that plays a critical role in regulating intracellular [cAMP](/entities/cyclic-amp) levels. The gene is located on chromosome 19q13.12 and encodes a protein of approximately 68 kDa. While PDE4C was initially characterized for its role in airway smooth muscle function and inflammatory responses, emerging evidence demonstrates important functions in the [central nervous system](/brain-regions/brain-overview), particularly in modulating [synaptic plasticity](/mechanisms/synaptic-plasticity), [memory formation](/mechanisms/memory-formation-mechanism), and [emotional regulation](/mechanisms/emotion-regulation-mechanism).

PDE4C belongs to the phosphodiesterase type 4 family, which specifically hydrolyzes cAMP and is distinguished by its expression pattern and regulation. The PDE4 family (including subtypes PDE4A, PDE4B, PDE4C, and PDE4D) is a major target for drug development, with several inhibitors approved for clinical use in inflammatory and respiratory diseases.

Gene Structure and Expression

Genomic Organization

The PDE4C gene contains multiple exons and gives rise to alternatively spliced variants. The gene promoter contains response elements for various transcription factors, including CREB, allowing activity-dependent regulation in [neurons](/entities/neurons). The upstream conserved regions (UCR) in the protein product provide additional regulatory complexity.

Tissue Distribution

PDE4C exhibits a distinctive expression pattern:

• Lung: Highest expression in airway smooth muscle and epithelial cells
• Brain: Moderate expression in [cortex](/brain-regions/cortex), hippocampus, and cerebellum
• Testis: High expression in spermatogenic cells
• Immune cells: Present in mast cells and eosinophils

Brain Expression

In the [brain](/brain-regions/brain-overview), PDE4C is expressed in:

• [Cerebral cortex](/brain-regions/cerebral-cortex) - particularly layer 5 pyramidal neurons
• [Hippocampus](/brain-regions/hippocampus) - CA1 and dentate gyrus regions
• [Cerebellum](/brain-regions/cerebellum) - Purkinje cells
• [Suprachiasmatic nucleus](/cell-types/suprachiasmatic-nucleus) - circadian regulation

Protein Structure and Function

Domain Architecture

The PDE4C protein contains key structural elements:

N-terminal upstream conserved region (UCR1): Regulatory domain involved in protein-protein interactions

Linker region (UCR2): Modulates catalytic activity

Catalytic domain: Contains the conserved PDE signature for cAMP hydrolysis

C-terminal region: Involved in subcellular targeting and dimerization

Enzymatic Activity

PDE4C specifically hydrolyzes:

• [cAMP](/entities/cyclic-amp): The sole substrate, distinguishing it from dual-substrate PDEs

The enzyme is constitutively active, but its activity can be modulated by:

• Phosphorylation by PKA
• Protein-protein interactions
• Alternative splicing variants

Role in Neuronal Signaling

cAMP Regulation

PDE4C plays a crucial role in neuronal [cAMP](/entities/cyclic-amp) signaling:

Signal termination: Hydrolyzes cAMP to terminate signaling cascades

Spatial encoding: Localized PDE activity creates cAMP gradients

Temporal control: Rapid cAMP turnover enables dynamic signaling

Synaptic Plasticity

PDE4C modulates [synaptic plasticity](/mechanisms/synaptic-plasticity) through cAMP regulation:

• [Long-term potentiation](/mechanisms/long-term-potentiation) (LTP): cAMP/PKA signaling is essential for LTP induction
• Long-term depression (LTD): cAMP dynamics regulate synaptic weakening
• Memory consolidation: CREB-mediated gene transcription requires proper cAMP signaling

Circadian Rhythm

PDE4C contributes to circadian regulation of cAMP in the [suprachiasmatic nucleus](/cell-types/suprachiasmatic-nucleus):

• cAMP oscillations drive circadian gene expression
• PDE4C activity shapes the amplitude of cAMP rhythms
• Disruption affects circadian behavior

Disease Associations

Alzheimer's Disease

PDE4C has significant implications for [Alzheimer's disease](/diseases/alzheimers-disease):

| Aspect | Mechanism | Evidence |
|--------|-----------|----------|
| Memory deficits | Elevated PDE4 activity reduces cAMP, impairing synaptic plasticity | PDE4 inhibitors improve memory in AD models |
| Amyloid pathology | cAMP dysregulation affects [amyloid precursor protein](/entities/app-protein) processing | Altered PDE4 expression in AD brain |
| [Tau](/proteins/tau) pathology | cAMP/PKA signaling influences tau phosphorylation | PDE4 inhibition reduces tau pathology |
| Therapeutic potential | PDE4 inhibitors as cognitive enhancers | Clinical trials in progress |

Parkinson's Disease

In [Parkinson's disease](/diseases/parkinsons-disease), PDE4C affects:

• Dopaminergic signaling: cAMP regulation in dopaminergic neurons
• Neuroprotection: PDE4 inhibitors protect against MPTP toxicity
• L-DOPA response: Modulation of dopaminergic therapy efficacy
• Neuroinflammation: Anti-inflammatory effects of PDE4 inhibition

Psychiatric Disorders

PDE4C variants have been associated with:

• Depression: PDE4 inhibition produces antidepressant effects
• Schizophrenia: Altered cAMP signaling in prefrontal cortex
• Addiction: cAMP dynamics in reward circuitry

Respiratory Diseases

The well-established role of PDE4C in:

• Asthma: Airway inflammation and bronchoconstriction
• COPD: Chronic inflammation and airflow limitation
• PDE4 inhibitors: Roflumilast, apremilast approved for clinical use

Therapeutic Targeting

PDE4 Inhibitors

Several PDE4 inhibitors have been developed:

| Inhibitor | Approval Status | Indications | CNS Penetration |
|-----------|-----------------|-------------|-----------------|
| Roflumilast | Approved (FDA/EMA) | COPD | Low |
| Apremilast | Approved (FDA/EMA) | Psoriasis, PsA | Low |
| Ibudilast | Approved (Japan) | Asthma, COPD | Moderate |
| Rolapitant | Approved (FDA) | CINV | N/A |

CNS-Targeted Development

Newer PDE4 inhibitors are being developed with improved brain penetration:

• PF-04449613: Brain-penetrant PDE4 inhibitor
• BMY 25802: Enhanced CNS penetration
• KW-4490: PDE4B-selective with CNS activity

Clinical Applications

PDE4 inhibition is explored for:

• Cognitive enhancement in dementia
• Neuroprotection in Parkinson's disease
• Treatment of depression
• Recovery from stroke

Interactions and Pathways

Signaling Network

PDE4C interacts with multiple pathways:

• Adenylyl cyclase: cAMP production
• PKA: cAMP effector kinase
• CREB: Transcription factor regulated by cAMP/PKA
• Epac: cAMP effector protein
• Beta-arrestin: Scaffold for signaling complexes

Protein Interactions

PDE4C forms complexes with:

• PDE4 subtypes (cross-talk)
• AKAPs (A-kinase anchoring proteins)
• Beta-catenin (signaling)
• Mdm2 (ubiquitination)

Animal Models

Knockout Studies

Pde4c knockout mice show:

• Elevated brain cAMP levels
• Enhanced hippocampal plasticity
• Altered inflammatory responses
• Viable and fertile

Pharmacological Studies

PDE4 inhibitor studies in models demonstrate:

• Memory enhancement in aged animals
• Neuroprotection in Parkinson's models
• Anti-depressant-like behaviors
• Reduced neuroinflammation

Clinical Significance

Genetic Associations

PDE4C polymorphisms have been linked to:

• Cognitive performance in elderly populations
• Response to antidepressants
• Asthma susceptibility
• Parkinson's disease risk

Biomarker Potential

PDE4C expression may serve as:

• Therapeutic target engagement marker
• Disease progression indicator
• Treatment response predictor

Research Directions

Current research focuses on:

• Developing brain-penetrant PDE4 inhibitors
• Understanding PDE4 isoform selectivity
• Identifying disease-specific mechanisms
• Combination therapy approaches

See Also

• [PDE4C Protein](/proteins/pde4c-protein)
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• [cAMP Signaling](/mechanisms/camp-dependent-signaling)
• [Synaptic Plasticity](/mechanisms/synaptic-plasticity)
• [Phosphodiesterases](/proteins/phosphodiesterases-family)

Background

The study of Pde4C — Phosphodiesterase 4C 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.

External Links

• [PubMed](https://pubmed.ncbi.nlm.nih.gov/) - Biomedical literature
• [Alzheimer's Disease Neuroimaging Initiative](https://adni.loni.usc.edu/) - Research data
• [Allen Brain Atlas](https://brain-map.org/) - Brain gene expression data

References

[Houslay MD, et al., (2005). PDE4 cAMP-specific phosphodiesterases. Prog Nucleic Acid Res Mol Biol (2005)](https://pubmed.ncbi.nlm.nih.gov/16151573/)

[Menniti FS, et al., (2006). PDE4 cAMP phosphodiesterases in CNS. CNS Drug Rev (2006)](https://pubmed.ncbi.nlm.nih.gov/17026726/)

[Unknown, PDE4 isoforms in brain function and disease. Trends Pharmacol Sci (2003) (2003)](https://pubmed.ncbi.nlm.nih.gov/12505665/)

[Unknown, PDE4 inhibition as therapeutic strategy in neurodegeneration. J Neurochem (2015) (2015)](https://pubmed.ncbi.nlm.nih.gov/25952654/)

[Unknown, cAMP signaling in Alzheimer's disease pathogenesis. Nat Rev Neurosci (2017) (2017)](https://pubmed.ncbi.nlm.nih.gov/28552259/)

[Unknown, Rolipram and PDE4 inhibitors: history and molecular targets. Handb Exp Pharmacol (2011) (2011)](https://pubmed.ncbi.nlm.nih.gov/20839080/)

[Unknown, PDE4 inhibitors in Parkinson's disease models. Neuropharmacology (2014) (2014)](https://pubmed.ncbi.nlm.nih.gov/24813812/)

[Unknown, PDE4C gene variants and neuropsychiatric disorders. Mol Psychiatry (2010) (2010)](https://pubmed.ncbi.nlm.nih.gov/19920835/)

Pathway Diagram

The following diagram shows the key molecular relationships involving PDE4C — Phosphodiesterase 4C discovered through SciDEX knowledge graph analysis: