Syntaxin-4

Syntaxin-4 (STX4) is a plasma membrane t-SNARE protein that mediates docking and fusion of transport vesicles with the cell surface (UniProt: Q12846). In neurons, it localizes to neurite tips and facilitates translocation of cargo proteins including the dopamine transporter SLC6A3 and glucose transporter SLC2A4 to the plasma membrane. The protein also plays roles in synaptic vesicle docking at presynaptic active zones and is required for normal hearing (UniProt: Q12846).

Syntaxin-4 is involved in vesicular trafficking pathways critical for neuronal function. A mutation in STX4 causes autosomal recessive deafness (DFNB123; UniProt: Q12846), highlighting its importance in specialized cell biology.

In Alzheimer's Disease, syntaxin-4 is upregulated in post-mortem AD brain tissue compared to age-matched controls, with a mean log2 fold-change of 0.23 across the examined subcellular fractions (Chaparral AD proteomics). This upregulation may reflect compensatory responses in synaptic vesicle trafficking or altered membrane dynamics associated with neurodegeneration.