Identification of SNAREs Involved in Synaptotagmin VII-regulated Lysosomal Exocytosis
Ca 2+ -regulated exocytosis of lysosomes has been recognized recently as a ubiquitous process, important for the repair of plasma membrane wounds. Lysosomal exocytosis is regulated by synaptotagmin VII, a member of the synaptotagmin family of Ca 2+ -binding proteins localized on lysosomes. Here we s...
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Published in | The Journal of biological chemistry Vol. 279; no. 19; pp. 20471 - 20479 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Society for Biochemistry and Molecular Biology
07.05.2004
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Subjects | |
Online Access | Get full text |
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Summary: | Ca 2+ -regulated exocytosis of lysosomes has been recognized recently as a ubiquitous process, important for the repair of plasma
membrane wounds. Lysosomal exocytosis is regulated by synaptotagmin VII, a member of the synaptotagmin family of Ca 2+ -binding proteins localized on lysosomes. Here we show that Ca 2+ -dependent interaction of the synaptotagmin VII C 2 A domain with SNAP-23 is facilitated by syntaxin 4. Specific interactions also occurred in cell lysates between the plasma
membrane t-SNAREs SNAP-23 and syntaxin 4 and the lysosomal v-SNARE TI-VAMP/VAMP7. Following cytosolic Ca 2+ elevation, SDS-resistant complexes containing SNAP-23, syntaxin 4, and TI-VAMP/VAMP7 were detected on membrane fractions.
Lysosomal exocytosis was inhibited by the SNARE domains of syntaxin 4 and TI-VAMP/VAMP7 and by cleavage of SNAP-23 with botulinum
neurotoxin E, thereby functionally implicating these SNAREs in Ca 2+ -regulated exocytosis of conventional lysosomes. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0021-9258 1083-351X |
DOI: | 10.1074/jbc.M400798200 |