Phosphoproteomic Network Analysis in the Sea Urchin Strongylocentrotus purpuratus Reveals New Candidates in Egg Activation

ABSTRACT: Fertilization triggers a dynamic symphony of molecular transformations induced by a rapid rise in intracellular calcium. Most prominent are surface alterations, metabolic activation, cytoskeletal reorganization, and cell cycle reentry. While the activation process appears to be broadly evolutionarily conserved, and protein phosphorylation is known to play a key role, the signaling networks mediating the response to fertilization are not well described. To address this gap, we performed a time course phosphoproteomic analysis of egg activation in the sea urchin Strongylocentrotus purpuratus, a system that offers biochemical tractability coupled with exquisite synchronicity. By coupling large-scale phosphopeptide enrichment with unbiased quantitative mass spectrometry, we identified striking changes in global phosphoprotein patterns at 2- and 5- min post fertilization as compared to unfertilized eggs. Overall, we mapped 8796 distinct phosphosite modifications on 2833 phosphoproteins, of which 15% were differentially regulated in early egg activation. Activated kinases were identified by phosphosite mapping, while enrichment analyses revealed conserved signaling cascades not previously associated with egg activation. This work represents the most comprehensive study of signaling associated with egg activation to date, providing both novel mechanistic insights and a valuable resource for the broader research community.

INSTRUMENT(S): LTQ Orbitrap Velos

ORGANISM(S): Strongylocentrotus Purpuratus (purple Sea Urchin)

TISSUE(S): Egg, Oocyte

SUBMITTER: Hongbo Guo  

LAB HEAD: Andrew Emili

PROVIDER: PXD002239 | Pride | 2015-08-04

REPOSITORIES: Pride