title: SNAP-25 is present in a SNARE complex in adrenal chromaffin cells.
abstract: SNAP-25 (synaptosomal-associated protein 25 kDa) is a target for botulinum neurotoxins A and E, which both inhibit neurotransmitter release, and was recently identified together with syntaxin and synaptobrevin as receptors for NSF and alpha-SNAP. We show that SNAP-25 was enriched in the microsomal fraction from adrenal medulla, although the level of SNAP-25 in adrenal medullary microsomes was about 20-fold less than in brain microsomes. Immunocytochemistry confirmed the presence of SNAP-25 in cultured chromaffin cells and showed plasma membrane staining. Using immunoprecipitation, we found that SNAP-25 was present in a complex with syntaxin, synaptobrevin, synaptotagmin, NSF, alpha-SNAP and other unidentified polypeptides. These data indicate that SNAP-25 in chromaffin cells is present in a complex similar to that identified in brain.
authors.affiliation: Physiological Laboratory, University of Liverpool, UK.
authors.forename: D
authors.initials: D
authors.lastname: Roth
authors.forename: R D
authors.initials: RD
authors.lastname: Burgoyne
mesh_terms: D000313:Adrenal Medulla / Q000737:chemistry*; D000595:Amino Acid Sequence; D000818:Animals; D002135:Calcium-Binding Proteins; D002352:Carrier Proteins / Q000032:analysis; D002417:Cattle; D002462:Cell Membrane / Q000737:chemistry; D005455:Fluorescent Antibody Technique; D008562:Membrane Glycoproteins / Q000032:analysis; D008565:Membrane Proteins / Q000032:analysis / Q000302:isolation & purification*; D008861:Microsomes / Q000737:chemistry; D008969:Molecular Sequence Data; D052066:N-Ethylmaleimide-Sensitive Proteins; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000302:isolation & purification*; D011233:Precipitin Tests; D050683:R-SNARE Proteins; D050825:Synaptosomal-Associated Protein 25; D050857:Synaptotagmins; D033921:Vesicular Transport Proteins
chemical_list: D002135:Calcium-Binding Proteins; D002352:Carrier Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D050683:R-SNARE Proteins; D050825:Synaptosomal-Associated Protein 25; D033921:Vesicular Transport Proteins; D050857:Synaptotagmins; D052066:N-Ethylmaleimide-Sensitive Proteins