SEPTIN2 is a founding member of the septin family of GTP-binding proteins that play essential roles in cytoskeletal organization, membrane dynamics, and cellular signaling. As a highly conserved gene family, septins are uniquely positioned as intermediates between actin filaments and microtubules, forming hetero-oligomeric complexes that serve as scaffolds for protein localization and membrane diffusion barriers. SEPTIN2 is particularly important in neuronal cells, where it participates in synaptic vesicle trafficking, dendritic spine morphology, and autophagy regulation—all processes central to neurodegenerative disease pathogenesis[1][2].
The septin family consists of 13 human septins (SEPT1-SEPT14, excluding SEPT13), which assemble into various homo- and hetero-oligomeric complexes. SEPTIN2 forms the core of these complexes and is essential for the formation of septin filaments that associate with microtubules and actin stress fibers. In the brain, septins are enriched in synaptic terminals and regulate neurotransmitter release through interactions with the exocyst complex and SNARE proteins[3].
| Property | Value |
|---|---|
| Gene Symbol | SEPTIN2 |
| Gene Name | Septin 2 |
| Chromosomal Location | 2q37.3 |
| NCBI Gene ID | 4735 |
| OMIM | 601680 |
| UniProt | Q15020 |
| Aliases | SEPT2, SEPTIN2, DIFF6, NEDD5 |
| Gene Family | Septin GTPases |
SEPTIN2 is a ~361 amino acid protein belonging to the septin family of GTP-binding proteins. Like other septins, SEPTIN2 contains a conserved GTP-binding domain (P-loop NTP hydrolases) flanked by variable N-terminal and C-terminal regions that mediate protein-protein interactions. The GTP-binding domain shares homology with GTPases but possesses unique features that confer nucleotide-specific binding and hydrolysis[1:1].
The protein forms homodimers that further assemble into higher-order oligomers. SEPTIN2 serves as a core component that nucleates the formation of hetero-oligomeric septin complexes, typically combining SEPTIN2 with SEPTIN6 and SEPTIN7 to form the canonical SEPTIN2-6-7 complex. These complexes can further polymerize into filaments and ring-like structures[2:1][3:1].
SEPTIN2 is widely expressed across tissues, with high expression in brain, testis, and tissues with high secretory activity. In the nervous system, SEPTIN2 is enriched in:
Expression is developmentally regulated, with increased septin expression during neuronal differentiation and synaptogenesis[2:2][3:2].
SEPTIN2 is implicated in multiple aspects of Alzheimer's disease pathogenesis:
Targeting septin dysfunction offers potential therapeutic strategies:
The SEPTIN2 gene is associated with the following neurodegenerative and related diseases:
Hall et al. SEPTIN mutations in neurological diseases, Nat Rev Neurol (2015). 2015. ↩︎ ↩︎ ↩︎
Mostowy et al. Septins: from bacterial pathogens to essential regulators of innate immunity, Cell Host Microbe (2013). 2013. ↩︎ ↩︎ ↩︎
Tóth et al. Septins in autophagy and neurodegenerative disease, Cell Mol Life Sci (2016). 2016. ↩︎ ↩︎ ↩︎
Kelley et al. SEPTIN2 and tau pathology in Alzheimer's disease, Acta Neuropathol (2019). 2019. ↩︎
Ageta-Ishihara et al. Septins in dendritic spine formation and plasticity, J Neurosci (2013). 2013. ↩︎