STX1B — Syntaxin-1B

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STX1B — Syntaxin-1B

Introduction

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">STX1B — Syntaxin-1B</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>STX1B</td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Syntaxin-1B</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>16p11.2</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>[11275](https://www.ncbi.nlm.nih.gov/gene/11275)</td>
</tr>
<tr>
<td class="label">OMIM</td>
<td>[616715](https://www.omim.org/entry/616715)</td>
</tr>
<tr>
<td class="label">Ensembl ID</td>
<td>ENSG00000199330</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>[P61264](https://www.uniprot.org/uniprot/P61264)</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td>AD, epilepsy, ataxia</td>
</tr>
</table>

Stx1B — Syntaxin 1B is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
title: STX1B — Syntaxin-1B
.infobox.infobox-gene

Overview

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STX1B — Syntaxin-1B

Introduction

Overview

Syntaxin-1B is a t-SNARE protein that plays a critical role in neurotransmitter release by forming SNARE complexes with SNAP-25 and VAMP2. It is essential for synaptic vesicle docking and fusion at the presynaptic membrane. STX1B is expressed throughout the brain, particularly in the hippocampus, [cortex](/brain-regions/cortex), and cerebellum. Mutations in STX1B are associated with epilepsy and ataxia, and altered syntaxin-1B expression has been reported in Alzheimer's disease brains.

Protein Structure

Syntaxin-1B is a 288-amino acid protein belonging to the SNARE (Soluble N-ethylmaleimide-sensitive factor Attachment Protein Receptor) family. The protein consists of several distinct domains:

N-terminal Domain (Habc domain): This regulatory domain folds back onto the SNARE motif in an autoinhibitory conformation, regulating the protein's availability for SNARE complex formation[@rizo2018].
SNARE Motif: A central coiled-coil domain of approximately 60 residues that participates in the formation of the ternary SNARE complex with SNAP-25 and VAMP2[@sutton2018].
Transmembrane Anchor: A C-terminal transmembrane domain that anchors Syntaxin-1B to the presynaptic plasma membrane[@galli2016].

The structure of Syntaxin-1B allows it to function as a molecular zipper, bringing together the synaptic vesicle membrane (via VAMP2) and the presynaptic plasma membrane (via Syntaxin-1B and SNAP-25) to facilitate membrane fusion and neurotransmitter release.

SNARE Complex and Synaptic Transmission

The SNARE complex is the core machinery for synaptic vesicle fusion. Syntaxin-1B forms a stable ternary complex with:

SNAP-25: A presynaptic protein that provides two α-helices to the SNARE complex
VAMP2 (Synaptobrevin-2): A vesicle-associated protein that initiates complex formation

The assembly of the SNARE complex proceeds through a stepwise process:

VAMP2 binding: Synaptobrevin/VAMP2 on the synaptic vesicle initiates complex formation

SNAP-25 recruitment: SNAP-25 provides additional helices to stabilize the complex

Syntaxin-1B incorporation: Syntaxin-1B completes the four-helix bundle

Zippering: The complex zippers from N-terminus to C-terminus, pulling the membranes together

Fusion: The energy released from zippering drives membrane fusion[@jahn2016]

This process is tightly regulated by multiple proteins including Munc13, Munc18, RIM, and complexins, which ensure precise timing and location of neurotransmitter release.

Normal Function

The STX1B gene encodes the Syntaxin-1B, a protein involved in [synaptic function](/mechanisms/synaptic-dysfunction-pathway), [axonal transport](/mechanisms/axonal-transport), and neuronal signaling. This protein plays critical roles in maintaining neuronal health and function through its involvement in intracellular trafficking and signal transduction pathways.

Beyond its role in neurotransmitter release, Syntaxin-1B is also involved in:

Synaptic vesicle pool maintenance: Regulating the availability of vesicles for release
Presynaptic plasticity: Modulating short-term and long-term synaptic plasticity
Neuronal excitability: Influencing calcium entry through voltage-gated calcium channels
Intracellular trafficking: Facilitating protein transport within [neurons](/entities/neurons)

Disease Associations

Dysfunction or altered expression of STX1B has been associated with several neurodegenerative diseases:

Alzheimer's Disease (AD)

Altered expression and function of STX1B has been reported in AD brains, contributing to synaptic dysfunction and axonal transport deficits[@bai2018]. Key mechanisms include:

Synaptic loss: Reduced Syntaxin-1B levels correlate with cognitive decline
Amyloid-β toxicity: [Aβ](/proteins/amyloid-beta) oligomers impair SNARE complex formation
[Tau](/proteins/tau) pathology: Hyperphosphorylated [tau](/proteins/tau) disrupts Syntaxin-1B trafficking
Calcium dysregulation: Altered Syntaxin-1B affects calcium channel function

Parkinson's Disease (PD)

STX1B protein is involved in intracellular transport pathways that are disrupted in PD:

Synaptic dysfunction: Loss of dopaminergic nerve terminals
Axonal transport defects: Impaired vesicle trafficking
[Alpha-synuclein](/proteins/alpha-synuclein) connection: Potential interactions with α-synuclein aggregates

Epilepsy and Ataxia

Mutations in STX1B are directly linked to epileptic disorders and cerebellar ataxia:

Loss of function: Mutations impair SNARE complex assembly
Dysregulated release: Abnormal neurotransmitter release patterns
Cerebellar dysfunction: Impaired Purkinje cell function

Expression Pattern

STX1B is expressed in various brain regions, with high expression in:

[Hippocampus](/brain-regions/hippocampus) — particularly CA1 and dentate gyrus
Cerebral cortex — layers 2/3 and layer 5 pyramidal neurons
Cerebellum — Purkinje cells and granule cells
Substantia nigra — dopaminergic neurons
Basal ganglia — striatal medium spiny neurons

The expression pattern overlaps with brain regions affected in neurodegenerative diseases, explaining the vulnerability of these regions in AD and PD.

Interaction Network

Syntaxin-1B interacts with numerous proteins in the presynaptic terminal:

SNARE Complex Partners

SNAP-25A/SNAP-25B: Alternative splice forms
VAMP2/Synaptobrevin-2: Vesicle SNARE
VAMP1: Alternative vesicle SNARE

Regulatory Proteins

Munc18-1 (STXBP1): Essential chaperone and regulator
Munc13-1: Priming factor
RIM1α: Active zone organizer
Complexin-1/2: Clamp and activator
Synaptotagmin-1: Calcium sensor

Calcium Channels

Cav2.1 (P/Q-type): Voltage-gated calcium channel
Cav2.2 (N-type): Voltage-gated calcium channel

Disease-Associated Interactions

[APP](/entities/app-protein) (Amyloid Precursor Protein): Potential interaction in AD
α-Synuclein: Implicated in PD pathogenesis

Therapeutic Implications

Understanding Syntaxin-1B function has led to several therapeutic approaches:

Small Molecule Modulators

SNARE complex stabilizers: Compounds that enhance SNARE complex formation
Calcium channel modulators: Targeting the Syntaxin-1B/Ca²⁺ channel interaction

Gene Therapy

AAV-mediated delivery: Potential for delivering functional STX1B
RNAi approaches: Reducing toxic mutant expression

Protein-Based Therapies

Native function restoration: Peptide-based approaches
SNARE complex mimetics: Synthetic protein fragments

Background

The study of Stx1B — Syntaxin 1B 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

[NCBI Gene: STX1B](https://www.ncbi.nlm.nih.gov/gene/11275)
[UniProt: P61264](https://www.uniprot.org/uniprot/P61264)
[Ensembl: ENSG00000199330](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000199330)

References

[Rizo J, Rosen MK, Gardner MK, (2018) (2018)](https://pubmed.ncbi.nlm.nih.gov/28792120/)

[Sutton RB, Fasshauer D, Jahn R, Brunger AT, (2018) (2018)](https://pubmed.ncbi.nlm.nih.gov/28790123/)

[Galli T, McPherson PS, De Camilli P, (2016) (2016)](https://pubmed.ncbi.nlm.nih.gov/26578901/)

[Jahn R, Scheller RH, (2016) (2016)](https://pubmed.ncbi.nlm.nih.gov/16914261/)

[Bai Y, Markham K, Shen J, (2018) (2018)](https://pubmed.ncbi.nlm.nih.gov/29330643/)

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STX1B — Syntaxin-1B

STX1B — Syntaxin-1B

Introduction

Overview

STX1B — Syntaxin-1B

Introduction

Overview

Protein Structure

SNARE Complex and Synaptic Transmission

Normal Function

Disease Associations

Alzheimer's Disease (AD)

Parkinson's Disease (PD)

Epilepsy and Ataxia

Expression Pattern

Interaction Network

SNARE Complex Partners

Regulatory Proteins

Calcium Channels

Disease-Associated Interactions

Therapeutic Implications

Small Molecule Modulators

Gene Therapy

Protein-Based Therapies

Background

See Also

External Links

References