Wangsun Choi - Academia.edu (original) (raw)
Papers by Wangsun Choi
Molecular Biology of the Cell, 2006
(VAMPs: synaptobrevin/VAMP-2, cellubrevin/VAMP-3, TI-VAMP/VAMP-7, and endobrevin/VAMP-8) is requi... more (VAMPs: synaptobrevin/VAMP-2, cellubrevin/VAMP-3, TI-VAMP/VAMP-7, and endobrevin/VAMP-8) is required. We demonstrate that VAMP-8 is required for release from dense core granules, alpha granules, and lysosomes. Platelets from VAMP-8 ؊/؊ mice have a significant defect in agonist-induced secretion, though signaling, morphology, and cargo levels appear normal. In contrast, VAMP-2 ؉/؊ , VAMP-3 ؊/؊ , and VAMP-2 ؉/؊ /VAMP-3 ؊/؊ platelets showed no defect. Consistently, tetanus toxin had no effect on secretion from permeabilized mouse VAMP-3 ؊/؊ platelets or human platelets, despite cleavage of VAMP-2 and/or -3. Tetanus toxin does block the residual release from permeabilized VAMP-8 ؊/؊ platelets, suggesting a secondary role for VAMP-2 and/or -3. These data imply a ranked redundancy of v-SNARE usage in platelets and suggest that VAMP-8 ؊/؊ mice will be a useful in vivo model to study platelet exocytosis in hemostasis and vascular inflammation.
Molecular Biology of the Cell, 2006
(VAMPs: synaptobrevin/VAMP-2, cellubrevin/VAMP-3, TI-VAMP/VAMP-7, and endobrevin/VAMP-8) is requi... more (VAMPs: synaptobrevin/VAMP-2, cellubrevin/VAMP-3, TI-VAMP/VAMP-7, and endobrevin/VAMP-8) is required. We demonstrate that VAMP-8 is required for release from dense core granules, alpha granules, and lysosomes. Platelets from VAMP-8 ؊/؊ mice have a significant defect in agonist-induced secretion, though signaling, morphology, and cargo levels appear normal. In contrast, VAMP-2 ؉/؊ , VAMP-3 ؊/؊ , and VAMP-2 ؉/؊ /VAMP-3 ؊/؊ platelets showed no defect. Consistently, tetanus toxin had no effect on secretion from permeabilized mouse VAMP-3 ؊/؊ platelets or human platelets, despite cleavage of VAMP-2 and/or -3. Tetanus toxin does block the residual release from permeabilized VAMP-8 ؊/؊ platelets, suggesting a secondary role for VAMP-2 and/or -3. These data imply a ranked redundancy of v-SNARE usage in platelets and suggest that VAMP-8 ؊/؊ mice will be a useful in vivo model to study platelet exocytosis in hemostasis and vascular inflammation.