SNAP-25 IS PRESENT ON CHROMAFFIN GRANULES AND ACTS AS A SNAP RECEPTOR

SNAP-25 is located on the plasma membrane and essential for exocytosis of neurotransmitters. It was suggested that SNAP-25 and syntaxin 1 vi a the interaction,vith VAMP-2 located on synaptic vesicles mediate the docking of the vesicles with the plasma membrane, In the present stud y, by means of biochemical and morphological analyses, we showed that SNAP-25 is present on chromaffin granules as well as on the plasma mem brane. Reconstitution and immunoprecipitation analyses revealed that S NAP-25 on chromaffin granules has essentially the same properties as d oes SNAP-25 on the plasma membrane.