It is also known as tomosyn, after 友, "friend" in Japanese, for its role as a binding protein.

[5][6][7] Syntaxin 1 is a component of the 7S and 20S SNARE complexes which are involved in docking and fusion of synaptic vesicles with the presynaptic plasma membrane.

Thus this protein is thought to be involved in neurotransmitter release by stimulating SNARE complex formation.

Alternatively spliced variants have been identified, but their biological validity has not been determined.

[7] Positional cloning suggested that tomosyn might inhibit neurotransmitter secretion in Caenorhabditis elegans neurons.