Visualization of regulated exocytosis with a granule-membrane probe using total internal reflection microscopy.

ABSTRACT: Secretory granules labeled with Vamp-green fluorescent protein (GFP) showed distinct signatures upon exocytosis when viewed by total internal reflection fluorescence microscopy. In approximately 90% of fusion events, we observed a large increase in fluorescence intensity coupled with a transition from a small punctate appearance to a larger, spreading cloud with free diffusion of the Vamp-GFP into the plasma membrane. Quantitation suggests that these events reflect the progression of an initially fused and spherical granule flattening into the plane of the plasma membrane as the Vamp-GFP simultaneously diffuses through the fusion junction. Approximately 10% of the events showed a transition from puncta to ring-like structures coupled with little or no spreading. The ring-like images corres

SUBMITTER: Allersma MW 

PROVIDER: S-EPMC519157 | biostudies-literature | 2004 Oct

REPOSITORIES: biostudies-literature