8.A.91 The Syntaxin (Syntaxin) Family
Syntaxins play roles in hormone and
neurotransmitter exocytosis and are potentially involved in
docking of synaptic vesicles at presynaptic active zones. During exocytosis, vesicle-associated v-SNARE (synaptobrevin) and target cell-associated t-SNAREs (syntaxin and SNAP-25) assemble into a core trans-SNARE complex. This complex
plays a versatile role at various stages of exocytosis ranging from the
priming to fusion pore formation and expansion, finally resulting in the
release or exchange of the vesicle content (Han et al. 2017). Syntaxins may also mediate Ca2+-regulation of exocytosis in the acrosomal reaction in sperm (Hutt et al. 2005). SNARE proteins (synaptobrevin, SNAP25 and syntaxin), synaptophysin, Ca2+/calmodulin,
and members of the synaptotagmin protein family (Syt1, Syt4, Syt7 and
Syt11) are involved in the balance and tight coupling of exo-endocytosis in neurons (Xie et al. 2017). Syntaxins regulate many channels and carriers including those listed in TCDB under TC#s 1.A.1.11.3, 1.A.1.11.4, 1.A.1.11.8, 1.A.1.2.13, 1.A.6.1.1 and 2.A.22.1.4 (see these entries) (Saxena et al. 2006).
Some syntaxins are listed under family 1.F.1 (see 1.F.1.1.3 and 1.F.1.1.4).