title: Complex gene organization of synaptic protein SNAP-25 in Drosophila melanogaster.
abstract: The evolutionarily conserved protein SNAP-25 (synaptosome-associated protein 25 kDa (kilodaltons)) is a component of the protein complex involved in the docking and/or fusion of synaptic vesicles in nerve terminals. We report here that the SNAP-25 gene (Snap) in the fruit fly Drosophila melanogaster has a complex organization with eight exons spanning more than 120 kb (kilobases). The exon boundaries coincide with those of the chicken SNAP-25 gene (Bark, 1993). Only a single exon 5 has been found in Drosophila, whereas human, rat, chicken, zebrafish and goldfish have two alternatively spliced versions of this exon. In situ hybridization and immunocytochemistry to whole mount embryos show that SNAP-25 mRNA and protein are detected in stage 14 and later developmental stages, and are mainly localized to the ventral nerve cord. Thus, Snap has an evolutionarily conserved and complex gene organization, and its onset of expression in Drosophila melanogaster correlates with a time in neuronal development when synapses begin to be formed and when other synapse-specific genes are switched on.
authors.affiliation: Department of Medical Pharmacology, Uppsala University, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Risinger
authors.forename: D L
authors.initials: DL
authors.lastname: Deitcher
authors.forename: I
authors.initials: I
authors.lastname: Lundell
authors.forename: T L
authors.initials: TL
authors.lastname: Schwarz
authors.forename: D
authors.initials: D
authors.lastname: Larhammar
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D005091:Exons; D006801:Humans; D007124:Immunoenzyme Techniques; D017403:In Situ Hybridization; D019476:Insect Proteins / Q000235:genetics*; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D050825:Synaptosomal-Associated Protein 25
chemical_list: D029721:Drosophila Proteins; D019476:Insect Proteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; C494208:SNAP25 protein, human; C494207:Snap25 protein, Drosophila; C494210:Snap25 protein, rat; D050825:Synaptosomal-Associated Protein 25