| Attribute |
Value |
Sources |
| Symbol |
FGF14 |
|
| Name |
Fibroblast Growth Factor 14 |
|
| Chromosome |
13q34 |
|
| NCBI Gene ID |
2254 |
|
| UniProt ID |
P15533 |
|
| Gene Type |
Protein coding |
|
| Alternative Names |
FGF14, FHF-2, FGF14A |
|
FGF14 (Fibroblast Growth Factor 14) is a member of the FGF family with predominant expression in neuronal tissues, particularly in the cerebellum and hippocampus. Like FGF13, FGF14 is an intracellular FGF that modulates neuronal function through interactions with ion channels, cytoskeletal proteins, and nuclear targets [@f gf14-neuron].
FGF14 has particular clinical relevance as mutations in this gene cause Spinocerebellar Ataxia type 27 (SCA27), an autosomal dominant disorder characterized by cerebellar degeneration, movement disorders, and cognitive impairment [@f gf14-sca27]. This positions FGF14 as a key player in cerebellar homeostasis and points to broader roles in neurodegenerative processes affecting both motor and cognitive systems.
FGF14 operates through unique intracellular mechanisms distinct from secreted FGFs:
1. Ion Channel Modulation
- Binds to voltage-gated sodium channels (NaV1.1-NaV1.9)
- Modulates channel gating properties
- Regulates neuronal excitability and firing patterns
- Influences action potential waveform and propagation
2. Protein-Protein Interactions
- Interacts with neuronal scaffolding proteins
- Binds to cytoskeletal elements (microtubules, actin)
- Associates with signaling molecules (PKC, CaMKII)
- Forms complexes with other FGF family members
3. Nuclear Functions
- Can localize to the nuclear compartment
- May regulate transcription
- Influences cell survival pathways
4. Synaptic Functions
- Localizes to presynaptic and postsynaptic compartments
- Regulates synaptic vesicle dynamics
- Modulates receptor trafficking
FGF14 provides neurotrophic support through multiple mechanisms:
| Mechanism |
Effect |
Disease Relevance |
| NaV modulation |
Excitability control |
Neuroprotection |
| Synaptic support |
Plasticity enhancement |
Memory/cognition |
| Survival signaling |
Anti-apoptotic |
Neuron preservation |
| Cerebellar function |
Motor coordination |
Ataxia prevention |
SCA27 is caused by heterozygous dominant mutations in FGF14:
1. Pathogenic Mechanisms
- Truncated or misfolded FGF14 protein
- Loss of normal function (haploinsufficiency)
- Possible toxic gain-of-function
- Disrupted ion channel interactions
2. Clinical Features
- Cerebellar ataxia (gait disturbance, incoordination)
- Dysarthria (speech difficulty)
- Ocular movement abnormalities
- Cognitive impairment in some cases
- Early onset (often adolescence/young adulthood)
3. Neuropathology
- Purkinje cell loss in cerebellum
- Degeneration of cerebellar nuclei
- Variable involvement of other brain regions
FGF14 contributes to AD pathogenesis [@f gf-ad]:
1. Synaptic Dysfunction
- FGF14 regulates synaptic plasticity
- Loss of FGF14 contributes to memory impairment
- Synaptic deficits are early features of AD
2. Hippocampal Vulnerability
- High FGF14 expression in hippocampus
- CA1 pyramidal neurons are particularly affected
- Contributes to episodic memory decline
3. Neurotrophic Support Deficit
- FGF14 provides survival signals to neurons
- Declining FGF13/14 contributes to neuron loss
- Complements other neurotrophic factor deficits
4. Excitotoxicity
- Sodium channel dysregulation in AD
- FGF14's channel-modulating function is protective
- Loss of this protection exacerbates excitotoxicity
FGF14 contributes to PD through :
1. Motor Circuit Dysfunction
- Cerebellar involvement in PD increasingly recognized
- FGF14 in cerebellar interneurons
- Contributes to movement abnormalities
2. Dopaminergic Neuron Support
- Expressed in regions connected to substantia nigra
- May provide trophic support to vulnerable neurons
- Loss contributes to degeneration
3. Neuroinflammation
- FGF14 modulated by inflammatory signals
- May participate in glial responses
- Chronic neuroinflammation drives progression
FGF14 changes observed in ALS:
- Motor neuron expression patterns
- Potential role in selective vulnerability
- Links to excitotoxicity mechanisms
FGF14 offers multiple therapeutic angles:
- Gene therapy: Deliver functional FGF14 to affected neurons
- Small molecule modulators: Enhance FGF14 signaling
- Sodium channel targeting: Preserve channel modulation function
- Neurotrophic approaches: Enhance overall trophic support
- Cerebellar protection: Target cerebellar degeneration
FGF14 shows region-specific neuronal expression:
- Cerebellum: Highest expression in Purkinje cells
- Hippocampus: Prominent in CA1-CA3 pyramidal neurons
- Cerebral cortex: Layers II-III and V pyramidal cells
- Brainstem: Various motor-related nuclei
- Thalamus: Relay neurons
Subcellular localization:
- Dendritic compartments
- Axon initial segments
- Synaptic terminals
- Nuclear and cytoplasmic compartments
- NaV1.1 (SCN1A)
- NaV1.2 (SCN2A)
- NaV1.6 (SCN8A)
- NaV1.7 (SCN9A)
- Voltage-gated calcium channels
- PKC isoforms
- CaMKII
- MAPK pathway components
- PI3K/Akt pathway
- Beta-tubulin
- Actin
- Neurofilament proteins
flowchart TD
subgraph FGF14_Functions
A["FGF14 Gene"] --> B["FGF14 Protein"]
B --> C["Cerebellar<br/>Expression"]
B --> D["Hippocampal<br/>Expression"]
C --> E["Motor<br/>Control"]
D --> F["Memory<br/>Function"]
end
subgraph SCA27_Pathology
G["FGF14<br/>Mutations"] --> H["Purkinje Cell<br/>Degeneration"]
H --> I["Cerebellar<br/>Ataxia"]
I --> J["Movement<br/>Disorder"]
end
subgraph AD_Pathology
K["FGF14<br/>Downregulation"] --> L["Synaptic<br/>Dysfunction"]
L --> M["Memory<br/>Impairment"]
K --> N["Hippocampal<br/>Vulnerability"]
N --> O["Cognitive<br/>Decline"]
end
subgraph PD_Pathology
P["FGF14<br/>Dysregulation"] --> Q["Motor Circuit<br/>Dysfunction"]
Q --> R["Movement<br/>Abnormalities"]
P --> S["Neuroinflammation"]
end
style G fill:#ffcdd2
style K fill:#ffcdd2
style P fill:#ffcdd2
style J fill:#b71c1c
style O fill:#b71c1c
style R fill:#b71c1c
- FGF13 — Related neuronal FGF with overlapping functions
- FGF2 — Classic neurotrophic FGF
- FGF9 — Another neuronal FGF