ANALYSIS OF PROTEIN-PHOSPHORYLATION IN FERTILIZED-EGGS OF RANA-DYBOWSKII

The phosphorylation of 100 and 170 kDa proteins was increased in respo nse to fertilization in eggs of Rana dybowskii. There was a transient increase of inositol 1,4,5-trisphosphate and diacylglycerol in fertili zed eggs. Treatment of 0.2 mM CaCl2 in unfertilized egg homogenate als o phosphorylated the 100 and 170 kDa proteins. Data suggest that the s perm signal increases IP3 content in egg cytoplasm, triggering Ca2+ re lease from internal storage into cell matrix to activate Ca2+-dependen t protein kinases, necessary for the early embryonic development.