Transient increase of a protein kinase activity identified to CK2 during sea urchin development

Using GST-EF-1 delta as an exogenous substrate, and EF-1 delta kinase activ ity was shown to increase transiently during early development of sea urchi n embryos. The basal activity of EF-1 delta kinase in unfertilized eggs was 150 fmoles/min/mg protein. The activity began to increase 10 h after ferti lization and reached its maximum level (8.4 x basal) at 24 h, The activity then declined to twice the basal value at 72 h postfertilization. The EF-1 delta kinase activity was identified to a CK2-type enzyme on the basis of i ts substrate specificity for EF-1 delta, crude casein and beta casein, its inhibition by heparin, DRB, 2,3-bisphosphoglycerate, and its stimulation by spermine, spermidine, and polylysin, Furthermore, the activity was inhibit ed by the synthetic peptide RRREEETEEE specific for CK2, DRB (200 mu M) and 2,3-bisphosphoglycerate (2.5 mM) blocked or delayed the transition from bl astula to gastrula of the embryos, suggesting a role for the kinase in earl y development. (C) 1999 Academic Press.