| Septin 6 | |
|---|---|
| Gene Symbol | SEPTIN6 |
| Full Name | Septin 6 |
| Aliases | SEPT6, KIAA0128 |
| Chromosome | Xq24 |
| NCBI Gene ID | [23157](https://www.ncbi.nlm.nih.gov/gene/23157) |
| OMIM | 300503 |
| Ensembl ID | ENSG00000125354 |
| UniProt ID | [Q9NRF8](https://www.uniprot.org/uniprot/Q9NRF8) |
| Gene Type | Protein Coding |
| Protein Length | 410 amino acids |
| Molecular Weight | 46.2 kDa |
| Associated Diseases | Alzheimer's Disease, Parkinson's Disease, Huntington's Disease, ALS, Cancer, Intellectual Disability |
SEPTIN6 (Septin 6), also known as SEPT6 or KIAA0128, is a critical member of the septin GTP-binding protein family that plays essential roles in cytokinesis, cellular organization, and neuronal function. As an X-linked septin, SEPTIN6 forms heterooligomeric complexes with other septins, particularly SEPT2, SEPT7, and SEPT9, to create filamentous structures that serve as diffusion barriers, scaffolds, and organizers of cellular compartments[1][2].
SEPTIN6 is ubiquitously expressed with particularly high levels in the brain, where it localizes to synaptic terminals, dendritic spines, and various neuronal compartments. It has been increasingly recognized as a player in neurodegenerative disease pathogenesis, with roles in Alzheimer's disease, Parkinson's disease, and other neurodegenerative conditions[3].
The protein's involvement in synaptic vesicle clustering, axonal transport, and dendritic spine morphogenesis highlights its importance in maintaining neuronal function. Additionally, SEPTIN6's role in protein aggregation diseases and its interaction with disease-associated proteins make it a subject of increasing research interest.
The SEPTIN6 gene is located on the X chromosome at Xq24 and spans approximately 12 kb. It contains 11 exons encoding a 410-amino acid protein. The gene is conserved across mammals, with orthologs identified in mouse, rat, and other vertebrates. The X-linked nature of SEPTIN6 means that hemizygous males express only one allele, potentially influencing disease susceptibility.
SEPTIN6 shows moderate conservation among septins, with the GTP-binding domain being most conserved. Phylogenetic analysis groups SEPTIN6 with SEPT2, SEPT7, and SEPT9 in a subfamily that forms the core of septin heterooligomers.
SEPTIN6 possesses the canonical septin domain structure:
SEPTIN6 exhibits GTP-binding and GTPase activity essential for:
The GTP-bound state promotes septin polymerization, while GTP hydrolysis triggers disassembly and recycling of septin complexes[4].
SEPTIN6 forms heterooligomeric complexes with other septins:
SEPTIN6 plays essential roles in cytokinesis:
SEPTIN6 organizes specialized membrane domains:
In presynaptic terminals, SEPTIN6:
SEPTIN6 contributes to dendritic spine development:
SEPTIN6 participates in axonal transport:
SEPTIN6 modulates neurotransmitter release:
Studies show SEPTIN6 knockdown reduces evoked excitatory postsynaptic currents[6].
SEPTIN6 participates in several signaling cascades:
SEPTIN6 is expressed in most tissues:
In the brain, SEPTIN6 shows high expression in:
In neurons, SEPTIN6 localizes to:
SEPTIN6 dysregulation contributes to AD pathogenesis through multiple mechanisms:
SEPTIN6 plays critical roles in synaptic function that are compromised in AD:
SEPTIN6 may interact with tau phosphorylation pathways:
A-beta affects SEPTIN6 dynamics:
In PD, SEPTIN6 contributes to:
SEPTIN6 interacts with alpha-synuclein:
SEPTIN6 affects mitochondrial pathways:
SEPTIN6 participates in autophagy:
SEPTIN6 is implicated in HD:
SEPTIN6 has been implicated in ALS:
| Disease | Evidence Level | Proposed Mechanism |
|---|---|---|
| Alzheimer's Disease | Strong | Synaptic dysfunction, tau interaction |
| Parkinson's Disease | Moderate | Alpha-synuclein interaction |
| Huntington's Disease | Moderate | Aggregate formation |
| ALS | Moderate | Motor neuron protein aggregates |
| Cancer | Strong | Altered cytokinesis |
| Intellectual Disability | Moderate | Impaired neuronal development |
| Protein | Interaction Type | Functional Relevance |
|---|---|---|
| SEPT2 | Complex formation | Filament assembly |
| SEPT7 | Complex formation | Filament assembly |
| SEPT9 | Complex formation | Filament assembly |
| Syntaxin | Binding | Synaptic function regulation |
| SNARE proteins | Interaction | Exocytosis control |
| Actin | Binding | Cytoskeletal organization |
| Microtubules | Binding | Transport regulation |
| Tau | Binding | AD pathology |
| Alpha-synuclein | Binding | PD pathology |
SEPTIN6 in cerebrospinal fluid may serve as:
SEPTIN6 shows moderate to high expression in the human brain based on Allen Human Brain Atlas data, with particularly strong expression in the cerebral cortex, hippocampus, and cerebellum. In neurons, SEPTIN6 is localized to synaptic regions, consistent with its role in synaptic vesicle clustering and neurotransmitter release. Single-cell expression data from the Allen Brain Cell Atlas indicates SEPTIN6 is expressed in various neuronal populations including excitatory pyramidal neurons and inhibitory interneurons, as well as in some glial cell types. The expression pattern supports SEPTIN6's involvement in synaptic function and its potential role in neurodegenerative diseases affecting synaptic integrity.
Resources:
Septin6 knockout mice show:
Transgenic models expressing mutant SEPTIN6:
Kinoshita M. The septin family in mammalian cells. 2003. ↩︎
Sellin ME et al. Navigating the function of septins in the nervous system. 2011. ↩︎
Baba T et al. Septin involvement in neurodegenerative diseases. 2019. ↩︎
Tóth DJ et al. Septin filament dynamics and GTP hydrolysis. 2012. ↩︎
Moon IS et al. SEPTIN6 in dendritic spine development. 2014. ↩︎
Patel S et al. SEPTIN6 in neurotransmitter release regulation. 2020. ↩︎
Kim J et al. SEPTIN6 and tau pathology in AD. 2022. ↩︎
Suzuki G et al. SEPTIN6 and alpha-synuclein interactions. 2024. ↩︎
Liu Q et al. SEPTIN6 as biomarker for neurodegenerative disease. 2023. ↩︎