Journal article
Intracellular distribution and functional importance of vesicle-associated membrane protein 2 in gastric parietal cells
Gastroenterology (New York, N.Y. 1943), Vol.123(1), pp.281-290
07/01/2002
DOI: 10.1053/gast.2002.34217
PMID: 12105856
Abstract
Background & Aims: Acid secretion by parietal cells involves secretagogue-dependent recycling of the H+-K+-ATPase. Proteins called soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) have been implicated as participants in membrane trafficking, docking, and fusing processes. Here we studied the intracellular distribution and functional importance of one SNARE protein, vesicle associated membrane protein-2 (VAMP-2), in gastric parietal cells. Methods: Using an adenoviral recombinant expression system encoding VAMP-2 (synaptobrevin-2) fused to the green fluorescent protein (GFP), we expressed the GFP-VAMP-2 protein in primary cultures of rabbit parietal cells, which enables us to visualize the dynamics of GFP-VAMP-2 in a variety of functional states by fluorescence microscopy. To ascertain the function of VAMP-2 in parietal cell activation, streptolysin-O permeabilized gastric glands were treated with tetanus toxin, a potent and preferential protease for VAMP-2, and acid secretion was measured. Results: In resting parietal cells GFP was detected throughout the cytoplasm in a pattern of distribution that was very similar to that of H+-K+-ATPase. After stimulation, we observed that the GFP–VAMP-2 translocated to the apical plasma membrane along with the H+-K+-ATPase. A relatively high degree of co-localization was detected between GFP–VAMP-2 and H+-K+-ATPase. Tetanus toxin inhibited cAMP/ATP-stimulated acid secretion by about 45% in permeabilized gastric glands with a concomitant reduction in the level of immunoreactive VAMP-2. Conclusions: Adenovirus-based GFP reporter fusion proteins can be used to efficiently study the functional dynamics of SNAREs. VAMP-2 is associated with tubulovesicle membranes in the parietal cell and plays a role in stimulation-associated membrane recruitment and acid secretion.
GASTROENTEROLOGY 2002;123:281-290
Details
- Title: Subtitle
- Intracellular distribution and functional importance of vesicle-associated membrane protein 2 in gastric parietal cells
- Creators
- Serhan Karvar - University of California, BerkeleyXuebiao Yao - University of California, BerkeleyJoseph G. Duman - University of California, BerkeleyKevin Hybiske - University of California, BerkeleyYuechueng Liu - University of Oklahoma Health Sciences CenterJohn G. Forte - University of California, Berkeley
- Resource Type
- Journal article
- Publication Details
- Gastroenterology (New York, N.Y. 1943), Vol.123(1), pp.281-290
- Publisher
- Elsevier Inc
- DOI
- 10.1053/gast.2002.34217
- PMID
- 12105856
- ISSN
- 0016-5085
- eISSN
- 1528-0012
- Language
- English
- Date published
- 07/01/2002
- Academic Unit
- Internal Medicine
- Record Identifier
- 9984695828502771
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