Redistribution of synaptic vesicles and their proteins in temperature-sensitive shibire(ts1) mutant Drosophila.
From an extract of Drosophila melanogaster head homogenates, a membrane fraction can be isolated that has the same sedimentation properties as vertebrate synaptic vesicles and contains Drosophila synaptotagmin. The fraction disappears from homogenates of temperature-sensitive (ts) mutant shibire(ts1) (shi(ts1)) flies paralyzed by exposure to non-permissive temperatures, and reappears on return to permissive temperatures. Since reversible, temperature-dependent depletion of synaptic vesicles is known to occur in shibire(ts1) flies, we conclude that the fraction we have identified contains synaptic vesicles. We have examined the fate of synaptic vesicle membrane proteins in shibire flies at nonpermissive temperatures and found that all of these vesicle antigens are transferred to rapidly sedimenting membranes and codistribute with a plasma membrane marker by both glycerol velocity and metrizamide density sedimentation and by confocal microscopy. Three criteria were used to establish that other neuron-specific antigens--neuronal synaptobrevin and cysteine-string proteins--are legitimate components of synaptic vesicles: cosedimentation with Drosophila synaptotagmin, immunoadsorption, and disappearance of these antigens from the vesicle fractions in paralyzed shibire flies.
van de Goor
J
J
Hormone Research Institute, University of California, San Francisco 94143-0534, USA.
Ramaswami
M
M
Kelly
R
R
D000595:Amino Acid Sequence; D000818:Animals; D015415:Biomarkers; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D005089:Exocytosis; D007301:Insect Hormones / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009479:Neuropeptides / Q000378:metabolism; D050683:R-SNARE Proteins; D013347:Subcellular Fractions / Q000378:metabolism; D013572:Synaptic Vesicles / Q000648:ultrastructure*; D013696:Temperature; D033921:Vesicular Transport Proteins
D015415:Biomarkers; D029721:Drosophila Proteins; D007301:Insect Hormones; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D009479:Neuropeptides; D050683:R-SNARE Proteins; D033921:Vesicular Transport Proteins; C084068:nsyb protein, Drosophila