In vitro exocytosis in sea urchin eggs requires a synaptobrevin-related protein.
Sea urchin eggs provide an efficient in vitro model of exocytosis. We have identified proteins in sea urchin eggs that cross-react with antibodies to mammalian synaptobrevin, synaptotagmin, SNAP-25, syntaxin and rab3a. We show that these proteins are localized to the sea urchin egg cortex, using western blotting and immunocytochemistry. Tetanus toxin light chain cleaves the synaptobrevin-related protein in vitro and inhibits calcium-induced exocytosis. These data demonstrate a conservation between phyla of protein sequence and molecular mechanisms thought to facilitate exocytosis and show that the sea urchin egg provides a unique in vitro exocytotic model with which to study the conserved protein machinery of membrane fusion during secretion.
Avery
J
J
Department of Physiological Sciences, Medical School, University of Newcastle upon Tyne, UK.
Hodel
A
A
Whitaker
M
M
D000818:Animals; D000918:Antibody Specificity; D015153:Blotting, Western; D002462:Cell Membrane / Q000737:chemistry / Q000502:physiology; D003594:Cytoplasmic Granules / Q000737:chemistry / Q000187:drug effects / Q000502:physiology; D005089:Exocytosis / Q000187:drug effects / Q000502:physiology*; D005260:Female; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D009865:Oocytes / Q000737:chemistry / Q000166:cytology*; D050683:R-SNARE Proteins; D012617:Sea Urchins; D013744:Tetanus Toxin / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology
D008565:Membrane Proteins; D050683:R-SNARE Proteins; D013744:Tetanus Toxin