Single secretory granules of live cells recruit syntaxin-1 and synaptosomal associated protein 25 (SNAP-25) in large copy numbers
2010 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 107, no 48, 20810-20815 p.Article in journal (Refereed) Published
Before secretory vesicles undergo exocytosis, they must recruit the proteins syntaxin-1 and synaptosomal associated protein 25 (SNAP-25) in the plasma membrane. GFP-labeled versions of both proteins cluster at sites where secretory granules have docked. Single-particle tracking shows that minority populations of both molecules are strongly hindered in their mobility, consistent with their confinement in nanodomains. We measured the fluorescence of granule-associated clusters, the fluorescence of single molecules, and the numbers of unlabeled syntaxin-1 and SNAP-25 molecules per cell. There was a more than 10-fold excess of SNAP-25 over syntaxin-1. Fifty to seventy copies each of syntaxin-1 and SNAP-25 molecules were associated with a single docked granule, many more than have been reported to be required for fusion.
Place, publisher, year, edition, pages
2010. Vol. 107, no 48, 20810-20815 p.
location-guided averaging, nanodomains, total internal reflection fluorescence, single molecules, single particle tracking
Medical and Health Sciences Neurosciences Cell and Molecular Biology
IdentifiersURN: urn:nbn:se:uu:diva-139382DOI: 10.1073/pnas.1014840107ISI: 000284762400043PubMedID: 21076040OAI: oai:DiVA.org:uu-139382DiVA: diva2:381326