STXBP2

This gene encodes a member of the STXBP/unc-18/SEC1 family. The encoded protein is involved in intracellular trafficking, control of SNARE (soluble NSF attachment protein receptor) complex assembly, and the release of cytotoxic granules by natural killer cells. Mutations in this gene are associated with familial hemophagocytic lymphohistiocytosis. Alternatively spliced transcript variants encoding different isoforms have been noted for this gene.

Full Name

syntaxin binding protein 2

Function

Involved in intracellular vesicle trafficking and vesicle fusion with membranes. Contributes to the granule exocytosis machinery through interaction with soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins that regulate membrane fusion. Regulates cytotoxic granule exocytosis in natural killer (NK) cells.

Biological Process

Biological Process intracellular protein transportManual Assertion Based On ExperimentIBA:GO_Central
Biological Process leukocyte mediated cytotoxicityManual Assertion Based On ExperimentIMP:UniProtKB
Biological Process neurotransmitter secretionManual Assertion Based On ExperimentIBA:GO_Central
Biological Process neutrophil degranulationManual Assertion Based On ExperimentIEP:UniProtKB
Biological Process regulation of mast cell degranulationISS:UniProtKB
Biological Process vesicle docking involved in exocytosisManual Assertion Based On ExperimentIBA:GO_Central
Biological Process vesicle-mediated transportManual Assertion Based On ExperimentIBA:GO_Central

Cellular Location

azurophil granule
cytolytic granule
cytosol
extracellular exosome
extracellular region
plasma membrane
presynapse
secretory granule
specific granule
tertiary granule

Involvement in disease

Hemophagocytic lymphohistiocytosis, familial, 5, with or without microvillus inclusion disease (FHL5):
A rare, autosomal recessive disorder characterized by immune dysregulation with hypercytokinemia, defective function of natural killer cell, and massive infiltration of several organs by activated lymphocytes and macrophages. The clinical features of the disease include fever, hepatosplenomegaly, cytopenia, and less frequently neurological abnormalities ranging from irritability and hypotonia to seizures, cranial nerve deficits and ataxia. Some patients may present in early infancy with severe diarrhea, prior to the onset of typical FHL features, whereas others present later in childhood and have a more protracted course without diarrhea. The early-onset diarrhea is due to enteropathy reminiscent of microvillus inclusion disease.