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Synaptotagmin VII Restricts Fusion Pore Expansion during Lysosomal Exocytosis

Synaptotagmin is considered a calcium-dependent trigger for regulated exocytosis. We examined the role of synaptotagmin VII (Syt VII) in the calcium-dependent exocytosis of individual lysosomes in wild-type (WT) and Syt VII knockout (KO) mouse embryonic fibroblasts (MEFs) using total internal reflec...

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Detalles Bibliográficos
Autores principales: Jaiswal, Jyoti K, Chakrabarti, Sabyasachi, Andrews, Norma W, Simon, Sanford M
Formato: Texto
Lenguaje:English
Publicado: Public Library of Science 2004
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC439782/
https://www.ncbi.nlm.nih.gov/pubmed/15226824
http://dx.doi.org/10.1371/journal.pbio.0020233
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author Jaiswal, Jyoti K
Chakrabarti, Sabyasachi
Andrews, Norma W
Simon, Sanford M
author_facet Jaiswal, Jyoti K
Chakrabarti, Sabyasachi
Andrews, Norma W
Simon, Sanford M
author_sort Jaiswal, Jyoti K
collection PubMed
description Synaptotagmin is considered a calcium-dependent trigger for regulated exocytosis. We examined the role of synaptotagmin VII (Syt VII) in the calcium-dependent exocytosis of individual lysosomes in wild-type (WT) and Syt VII knockout (KO) mouse embryonic fibroblasts (MEFs) using total internal reflection fluorescence microscopy. In WT MEFs, most lysosomes only partially released their contents, their membrane proteins did not diffuse into the plasma membrane, and inner diameters of their fusion pores were smaller than 30 nm. In Syt VII KO MEFs, not only was lysosomal exocytosis triggered by calcium, but all of these restrictions on fusion were also removed. These observations indicate that Syt VII does not function as the calcium-dependent trigger for lysosomal exocytosis. Instead, it restricts the kinetics and extent of calcium-dependent lysosomal fusion.
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spelling pubmed-4397822004-07-02 Synaptotagmin VII Restricts Fusion Pore Expansion during Lysosomal Exocytosis Jaiswal, Jyoti K Chakrabarti, Sabyasachi Andrews, Norma W Simon, Sanford M PLoS Biol Research Article Synaptotagmin is considered a calcium-dependent trigger for regulated exocytosis. We examined the role of synaptotagmin VII (Syt VII) in the calcium-dependent exocytosis of individual lysosomes in wild-type (WT) and Syt VII knockout (KO) mouse embryonic fibroblasts (MEFs) using total internal reflection fluorescence microscopy. In WT MEFs, most lysosomes only partially released their contents, their membrane proteins did not diffuse into the plasma membrane, and inner diameters of their fusion pores were smaller than 30 nm. In Syt VII KO MEFs, not only was lysosomal exocytosis triggered by calcium, but all of these restrictions on fusion were also removed. These observations indicate that Syt VII does not function as the calcium-dependent trigger for lysosomal exocytosis. Instead, it restricts the kinetics and extent of calcium-dependent lysosomal fusion. Public Library of Science 2004-08 2004-06-29 /pmc/articles/PMC439782/ /pubmed/15226824 http://dx.doi.org/10.1371/journal.pbio.0020233 Text en Copyright: © 2004 Jaiswal et al. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Jaiswal, Jyoti K
Chakrabarti, Sabyasachi
Andrews, Norma W
Simon, Sanford M
Synaptotagmin VII Restricts Fusion Pore Expansion during Lysosomal Exocytosis
title Synaptotagmin VII Restricts Fusion Pore Expansion during Lysosomal Exocytosis
title_full Synaptotagmin VII Restricts Fusion Pore Expansion during Lysosomal Exocytosis
title_fullStr Synaptotagmin VII Restricts Fusion Pore Expansion during Lysosomal Exocytosis
title_full_unstemmed Synaptotagmin VII Restricts Fusion Pore Expansion during Lysosomal Exocytosis
title_short Synaptotagmin VII Restricts Fusion Pore Expansion during Lysosomal Exocytosis
title_sort synaptotagmin vii restricts fusion pore expansion during lysosomal exocytosis
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC439782/
https://www.ncbi.nlm.nih.gov/pubmed/15226824
http://dx.doi.org/10.1371/journal.pbio.0020233
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