8.A.91.1.4
Syntaxin-1A (Stx1; Stx1A; Sx1) of 288 aas.  Co-localizes with L-type Ca²⁺-channels (Cav1.2) in nano clusters at the plasma membrane (Sajman et al. 2017). Munc18 bridges the few syntaxin molecules residing on granules to the syntaxin cluster on the plasma membrane, suggesting that the number of syntaxins on vesicles determines docking and possibly fusion probability  (Borisovska 2018). Munc18-1 (P61764; see 1.F.1.1.3)), a neuronal protein that interacts with syntaxin 1 and is required for synaptic vesicle exocytosis, depends on two Munc18-1-interacting proteins called Mint1 or APBA1 (TC# 8.A.24.2.2) and Mint2 or SAPBA2 (TC# 8.A.24.2.3) (Okamoto and Südhof 1997). Syntaxin 1A has a binding site in its H3 domain that is critical for targeting of the H⁺-ATPase to the apical membrane of renal epithelial cells (Li et al. 2005). The mechanisms regulating syntaxin-1 nanoclustering on the plasma membrane have been considered (Padmanabhan et al. 2019). The syntaxin-1A transmembrane domain has been reconstituted in artificial membranes (Kramer et al. 2022).