Disease relevance of Stx3

• The clostridial neurotoxin-insensitive soluble N-ethylmaleimide-sensitive factor attachment protein (SNAP) receptors, tetanus neurotoxin-insensitive (TI)-vesicle-associated membrane protein (VAMP)/VAMP7, SNAP23, and syntaxin 3 have recently been implicated in transport of exocytotic vesicles to the apical plasma membrane of epithelial cells [1].

High impact information on Stx3

• Immunofluorescent staining of rat retina sections confirmed that syntaxin 3 is expressed by photoreceptor and bipolar cells in the retina [2].
• Furthermore, two of these SNAREs, vesicle-associated membrane protein and syntaxin 3, were associated with H+/K(+)-ATPase-containing tubulovesicles while the remainder were excluded from this compartment [3].
• Retinal pigment epithelial cells lack expression of the normally apical-specific syntaxin 3 [4].
• Both exocytosis of the minor regulated pathway and the potentiation-inducing treatments induce relocation of immunostained subapical puncta of the SNARE protein syntaxin 3 into the apical plasma membrane [5].
• Induction of long-term potentiation in vivo regulates alternate splicing to alter syntaxin 3 isoform expression in rat dentate gyrus [6].

Anatomical context of Stx3

• We now report a more widespread distribution of syntaxin 3 in a variety of renal epithelial cells after antigen retrieval [7].
• Association of syntaxin 3 and vesicle-associated membrane protein (VAMP) with H+/K(+)-ATPase-containing tubulovesicles in gastric parietal cells [3].
• A significant proportion of syntaxin 3 (25%) was detected in subcellular fractions containing transport vesicles [8].
• Rat basophilic leukemia cells express syntaxin-3 and VAMP-7 in granule membranes [9].

Other interactions of Stx3

• Contrary to results from in vitro binding assays, SNAP-23 was found predominantly associated with syntaxin 3 [10].
• RT-PCR experiments using microdissected tubules and vascular structures from the kidney revealed that syntaxin-3 mRNA, but not syntaxin-2, is expressed in collecting duct cells [11].
• Immunoperoxidase labeling of thin cryosections combined with immunogold electron microscopy showed that, in contrast to the labeling seen for syntaxin-4, syntaxin-3 labeling in medullary collecting duct was predominantly in the basolateral plasma membrane of intercalated cells [11].

References