Syntaxin-binding protein 4 (STXBP4)

Syntaxin-binding protein 4 (STXBP4) is a cytoplasmic, scaffolding protein that regulates the translocation of transport vesicles—particularly those containing the glucose transporter SLC2A4/GLUT4—from the cytoplasm to the plasma membrane, acting mainly as an inhibitor in the absence of insulin stimulation. STXBP4 binds syntaxin 4 (STX4) and blocks its association with VAMP2, thus preventing vesicle fusion and GLUT4 insertion into the membrane; upon insulin stimulation, this interaction is disrupted, facilitating glucose uptake. It is further involved in positive regulation of cell cycle progression and protein stabilization. STXBP4 also forms complexes with Hippo pathway components to inhibit YAP activity, linking it to cell proliferation control and tumorigenesis. Diseases associated with STXBP4 include inflammatory bowel disease, and its involvement in regulatory pathways suggests broader relevance in diabetes and cancer biology.

Other names

Syntaxin-binding protein 4STXBP4STX4-interacting proteinSynipMGC50337Syntaxin 4-interacting proteinsyntaxin 4 interacting protein

Drugs could modulate glucose homeostasis by affecting STXBP4’s inhibition of GLUT4 translocation; Drugs targeting Hippo pathway may modulate STXBP4 function