Fig. 3. The increase in the association of SgIF4G and eIF4E following fertilization correlates with the dissociation of eIF4E and 4E-BP, and occurs after modifications of SgIF4G protein. (A) SgIF4G associates with eIF4E when 4E-BP dissociates from eIF4E. m⁷GTP-column affinity-purified egg proteins extracted prior to or at the indicated times after fertilization were resolved by 15% SDS-PAGE and subjected to western blotting using anti-4E-BP2 (bottom), anti-eIF4E (middle) and anti-SgIF4G (top) antibodies. (B) SgIF4G modifications occur rapidly following fertilization. Supernatants obtained from low-speed centrifugation of egg homogenates prepared prior to or at the indicated times following fertilization, were resolved by 7.5% SDS-PAGE and subjected to western blotting using anti-SgIF4G (top). Anti-actin was used as loading control (bottom).