| Septin-7 (SEPT7) |
|---|
| Gene | [SEPT7](/genes/sept7) |
| UniProt ID | [Q16181](https://www.uniprot.org/uniprot/Q16181) |
| PDB | 5DY1, 6UPN |
| Molecular Weight | 50.6 kDa |
| Localization | Cytoplasm, dendritic spines, growth cones |
| Family | Septin family, Group B |
| Disease | AD, ASD, Epilepsy |
Septin-7 is a member of the septin family of GTP-binding proteins that form filamentous structures in neurons. Septins are essential components of the neuronal cytoskeleton, playing critical roles in dendritic spine morphology, synaptic function, and neuronal migration. Septin-7 forms hetero-oligomers with other septins and is particularly important for maintaining spine architecture and synaptic plasticity.
Septin-7 has characteristic septin architecture:
- N-terminal domain: Contains P-loop GTPase domain
- GTPase domain: Binds and hydrolyzes GTP
- Coiled-coil domain (C-terminal): Mediates hetero-oligomerization
- Septin unique element (SUE): Conserved septin-specific region
Septin-7 polymerization:
- Forms hetero-hexamers and hetero-octamers with SEPT2, SEPT6
- Assembles into filaments and higher-order structures
- Associated with cell membranes via polybasic regions
Septin-7 has critical neuronal functions:
- Dendritic Spine Morphology: Controls spine shape and stability
- Synaptic Function: Scaffolds postsynaptic proteins
- Axon Guidance: Growth cone navigation
- Neuronal Migration: Cortical development
- Membrane Remodeling: Forms diffusion barriers
- Cytokinetic Ring: Cell division (non-neuronal)
Spine function:
- Septin-7 localizes to spine base
- Forms diffusion barrier between spine head and neck
- Maintains compartmentalization of signaling molecules
- Regulates AMPA receptor trafficking
Septin-7 in AD:
- Reduced expression: In AD hippocampus
- Spine loss: Septin-7 disruption contributes
- Aβ toxicity: Affects septin cytoskeleton
- Synaptic dysfunction: Loss of spine compartmentalization
Mechanisms:
- Aβ oligomers disrupt septin filaments
- Impaired spine maintenance
- Loss of synaptic plasticity
- Memory deficits
Septin-7 implicated in ASD:
- Genetic variants associated with ASD
- Essential for neurodevelopment
- Spine morphology defects
- Synaptic dysfunction
Septin-7 mutations in epilepsy:
- Cortical malformations
- Impaired neuronal migration
- Network hyperexcitability
| Strategy |
Mechanism |
Status |
| Septin stabilizers |
Enhance filament assembly |
Preclinical |
| Spine protectors |
Preserve septin function |
Research |
| GTPase modulators |
Regulate septin dynamics |
Research |