Dephosphorylation of eIF2α is essential for protein synthesis increase and cell cycle progression after sea urchin fertilization

► Fertilization of the sea urchin eggs triggers a rapid increase in protein synthesis activity. ► Cell cycle progression depends on protein synthesis activity. ► Fertilization triggers eIF2α dephosphorylation. ► Phosphorylated eIF2α inhibits protein synthesis, and induces cell cycle arrest. ► eIF2α dephosphorylation is necessary for completion of first cell cycle.