Syntaxin-3 (STX3)

Syntaxin-3 (STX3) is a member of the syntaxin family of SNARE (Soluble NSF Attachment Receptor) proteins involved in vesicular trafficking and membrane fusion, with key roles in exocytosis, especially in polarized epithelial cells where it is essential for apical membrane fusion and epithelial polarity[5][6]. In neurons, STX3 contributes to neurite growth and the sorting of cargo in specialized subcellular compartments, including photoreceptors where it mediates disc and rim protein trafficking for vision[4]. Alternative splicing generates a soluble isoform, STX3S, which functions as a transcriptional coregulator by entering the nucleus and interacting with transcription factors such as ETV4 and ATF2, affecting gene expression programs linked to cancer and cell proliferation[1][7]. Mutations in STX3 cause microvillus inclusion disease, a severe congenital enteropathy, and impaired STX3 function can also contribute to photoreceptor degeneration and cancer biology[3][4][5]. STX3 interacts with proteins such as SNAP-25, SNAP23, SNAP29, myosin Vb, Rab11a, and Munc18b[3][5]. The protein has regulatory domains that bind ubiquitin, suggesting roles in trafficking regulation and proteostasis[2]. Presently, no drugs are known to directly target STX3, but its roles in membrane fusion and gene regulation present potential future therapeutic avenues.

Other names

Syntaxin-3STX3STX3ADIAR12MVID2RDMVIDsyntaxin-3syntaxin 3Asyntaxin 3Bsyntaxin 3

Drugs targeting SNAREs would likely affect vesicle fusion and exocytosis; no drugs directly indicated for STX3 in current sources