RGD Reference Report - Role of SNAP-23 in trafficking of H+-ATPase in cultured inner medullary collecting duct cells. - Rat Genome Database
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Role of SNAP-23 in trafficking of H+-ATPase in cultured inner medullary collecting duct cells.

Authors: Banerjee, A  Li, G  Alexander, EA  Schwartz, JH 
Citation: Banerjee A, etal., Am J Physiol Cell Physiol. 2001 Apr;280(4):C775-81.
RGD ID: 2306548
Pubmed: (View Article at PubMed) PMID:11245593

The trafficking of H+-ATPase vesicles to the apical membrane of inner medullary collecting duct (IMCD) cells utilizes a mechanism similar to that described in neurosecretory cells involving soluble N-ethylmaleimide-sensitive factor attachment protein target receptor (SNARE) proteins. Regulated exocytosis of these vesicles is associated with the formation of SNARE complexes. Clostridial neurotoxins that specifically cleave the target (t-) SNARE, syntaxin-1, or the vesicle SNARE, vesicle-associated membrane protein-2, reduce SNARE complex formation, H+-ATPase translocation to the apical membrane, and inhibit H+ secretion. The purpose of these experiments was to characterize the physiological role of a second t-SNARE, soluble N-ethylmaleimide-sensitive factor attachment protein (SNAP)-23, a homologue of the neuronal SNAP-25, in regulated exocytosis of H+-ATPase vesicles. Our experiments document that 25-50 nM botulinum toxin (Bot) A or E cleaves rat SNAP-23 and thereby reduces immunodetectable and (35)S-labeled SNAP-23 by >60% within 60 min. Addition of 25 nM BotE to IMCD homogenates reduces the amount of the 20 S-like SNARE complex that can be immunoprecipitated from the homogenate. Treatment of intact IMCD monolayers with BotE reduces the amount of H+-ATPase translocated to the apical membrane by 52 +/- 2% of control and reduces the rate of H+ secretion by 77 +/- 3% after acute cell acidification. We conclude that SNAP-23 is a substrate for botulinum toxin proteolysis and has a critical role in the regulation of H+-ATPase exocytosis and H+ secretion in these renal epithelial cells.

Annotation

Gene Ontology Annotations    

Biological Process

Objects Annotated

Genes (Rattus norvegicus)
Nsf  (N-ethylmaleimide sensitive factor, vesicle fusing ATPase)
Snap23  (synaptosome associated protein 23)
Stx1b  (syntaxin 1B)
Vamp2  (vesicle-associated membrane protein 2)


Additional Information