STX11 Gene: Syntaxin 11 Function, Mutations, and Associated Diseases

STX11 encodes syntaxin 11, a member of the syntaxin family of SNARE proteins involved in vesicle docking and fusion. Syntaxin 11 is predominantly expressed in immune cells and is essential for cytotoxic granule exocytosis in natural killer (NK) cells and cytotoxic T lymphocytes (CTLs). Mutations in STX11 cause familial hemophagocytic lymphohistiocytosis type 4 (FHL4), a severe hyperinflammatory disorder characterized by impaired lymphocyte cytotoxicity.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• KEGG: hsa04130 - SNARE interactions in vesicular transport

• Reactome: R-HSA-202733 - Cell surface interactions at the vascular wall

• Reactome: R-HSA-168249 - Innate Immune System

• Reactome: R-HSA-2172127 - Docking and fusion of secretory granules

Syntaxin 11 is a 287-amino-acid protein (32 kDa) belonging to the syntaxin family of t-SNAREs. It contains a C-terminal transmembrane domain and a SNARE motif that mediates interactions with other SNARE proteins (e.g., VAMP8, SNAP23) to facilitate membrane fusion. In cytotoxic lymphocytes, syntaxin 11 is essential for the fusion of cytotoxic granules with the plasma membrane, enabling the release of perforin and granzymes to kill target cells. Loss of syntaxin 11 function leads to familial hemophagocytic lymphohistiocytosis type 4 (FHL4).