title: Phospho-regulation pathways during egg activation in Drosophila melanogaster.
abstract: Egg activation is the series of events that transition a mature oocyte to an egg capable of supporting embryogenesis. Increasing evidence points toward phosphorylation as a critical regulator of these events. We used Drosophila melanogaster to investigate the relationship between known egg activation genes and phosphorylation changes that occur upon egg activation. Using the phosphorylation states of four proteins-Giant Nuclei, Young Arrest, Spindly, and Vap-33-1-as molecular markers, we showed that the egg activation genes sarah, CanB2, and cortex are required for the phospho-regulation of multiple proteins. We show that an additional egg activation gene, prage, regulates the phosphorylation state of a subset of these proteins. Finally, we show that Sarah and calcineurin are required for the Anaphase Promoting Complex/Cyclosome (APC/C)-dependent degradation of Cortex following egg activation. From these data, we present a model in which Sarah, through the activation of calcineurin, positively regulates the APC/C at the time of egg activation, which leads to a change in phosphorylation state of numerous downstream proteins.
authors.affiliation: Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853.
authors.forename: Amber R
authors.initials: AR
authors.lastname: Krauchunas
authors.forename: Katharine L
authors.initials: KL
authors.lastname: Sackton
authors.forename: Mariana F
authors.initials: MF
authors.lastname: Wolfner
mesh_terms: D064173:Anaphase-Promoting Complex-Cyclosome / Q000378:metabolism; D000818:Animals; D019703:Calcineurin / Q000378:metabolism; D002135:Calcium-Binding Proteins; D064199:Cdc20 Proteins / Q000378:metabolism; D029721:Drosophila Proteins / Q000378:metabolism; D004331:Drosophila melanogaster / Q000378:metabolism* / Q000502:physiology; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D009865:Oocytes / Q000378:metabolism* / Q000502:physiology; D010766:Phosphorylation; D059748:Proteolysis
chemical_list: D002135:Calcium-Binding Proteins; D064199:Cdc20 Proteins; D029721:Drosophila Proteins; D047908:Intracellular Signaling Peptides and Proteins; C513393:Sra protein, Drosophila; C577503:cort protein, Drosophila; D064173:Anaphase-Promoting Complex-Cyclosome; D019703:Calcineurin
keywords: Anaphase Promoting Complex/Cyclosome (APC/C); Drosophila; calcineurin; egg activation; phosphorylation