Stx1a
Function
Plays an essential role in hormone and neurotransmitter calcium-dependent exocytosis and endocytosis (PubMed:17301173, PubMed:18167541, PubMed:20484665, PubMed:22411134, PubMed:28813412, PubMed:7901002). Part of the SNARE (Soluble NSF Attachment Receptor) complex composed of SNAP25, STX1A and VAMP2 which mediates the fusion of synaptic vesicles with the presynaptic plasma membrane (PubMed:14665625, PubMed:16888141, PubMed:19571812). STX1A and SNAP25 are localized on the plasma membrane while VAMP2 resides in synaptic vesicles. The pairing of the three SNAREs from the N-terminal SNARE motifs to the C-terminal anchors leads to the formation of the SNARE complex, which brings membranes into close proximity and results in final fusion (PubMed:14665625, PubMed:16888141, PubMed:19571812). Participates in the calcium-dependent regulation of acrosomal exocytosis in sperm (By similarity). Also plays an important role in the exocytosis of hormones such as insulin or glucagon-like peptide 1 (GLP-1) (By similarity).
Post-translational modifications
Phosphorylated by CK2. Phosphorylation at Ser-188 by DAPK1 significantly decreases its interaction with STXBP1.
(Microbial infection) Targeted and hydrolyzed by C.botulinum neurotoxin type C (BoNT/C), which hydrolyzes the 253-Lys-|-Ala-254 bond (PubMed:7737992). Cleavage inhibits neurotransmitter release (PubMed:7901002).
Phosphorylated by CK2 (By similarity). Phosphorylation at Ser-188 by DAPK1 significantly decreases its interaction with STXBP1 (By similarity).
Sumoylated, sumoylation is required for regulation of synaptic vesicle endocytosis.
Sequence Similarities
Belongs to the syntaxin family.
Tissue Specificity
Expressed predominantly in cerebral cortex, hippocampus, cerebellum, adrenal medulla and retina with weak expression detected in non-neuronal tissues.
Cellular localization
- Cytoplasmic vesicle
- Secretory vesicle
- Synaptic vesicle membrane
- Single-pass type IV membrane protein
- Cell membrane
- Synapse
- Synaptosome
- Colocalizes with KCNB1 at the cell membrane (PubMed:17301173). Colocalizes with PLCL1 at the cell membrane (PubMed:22673903).
Alternative names
Sap, Syntaxin-1A, Neuron-specific antigen HPC-1, Synaptotagmin-associated 35 kDa protein, P35A