Syt1
Domain
The first C2 domain mediates Ca(2+)-dependent phospholipid binding.
The second C2 domain mediates interaction with SV2A and probably with STN2.
Function
Calcium sensor that participates in triggering neurotransmitter release at the synapse (PubMed:2333096, PubMed:30107533). May have a regulatory role in the membrane interactions during trafficking of synaptic vesicles at the active zone of the synapse. It binds acidic phospholipids with a specificity that requires the presence of both an acidic head group and a diacyl backbone. A Ca(2+)-dependent interaction between synaptotagmin and putative receptors for activated protein kinase C has also been reported. It can bind to at least three additional proteins in a Ca(2+)-independent manner; these are neurexins, syntaxin and AP2. Plays a role in dendrite formation by melanocytes.
(Microbial infection) Receptor for C.botulinum neurotoxin type B (BoNT/B, botB); interaction is improved in the presence of gangliosides (PubMed:14504267, PubMed:17167418, PubMed:8144634). BoNT/B toxin binds to the membrane proximal vesicular domain of Syt1 (residues 32-51) (PubMed:14504267, PubMed:17167421).
(Microbial infection) Receptor for C.botulinum neurotoxin type G (BoNT/G, botG); unlike the case with BoNT/B, interaction is not improved in the presence of gangliosides (PubMed:15123599, PubMed:20219474). BoNT/G toxin binds to the vesicular domain of Syt1 (residues 32-53) (PubMed:15123599, PubMed:20219474).
Post-translational modifications
Glycosylated.
Sequence Similarities
Belongs to the synaptotagmin family.
Tissue Specificity
Expressed in the brain (at protein level) (PubMed:17190793). Predominantly expressed in rostral, phylogenetically younger brain regions, and in some endocrine tissues.
Cellular localization
- Cytoplasmic vesicle
- Secretory vesicle membrane
- Single-pass membrane protein
- Cytoplasmic vesicle
- Secretory vesicle
- Synaptic vesicle membrane
- Single-pass membrane protein
- Cytoplasmic vesicle
- Secretory vesicle
- Chromaffin granule membrane
- Single-pass membrane protein
- Cytoplasm
Alternative names
Synaptotagmin-1, Synaptotagmin I, p65, SytI, Syt1
Database links
swissprot:P21707 swissprot:P29101 entrezGene:25716 entrezGene:24805