Ys. Kam et al., ANALYSIS OF PROTEIN-PHOSPHORYLATION IN FERTILIZED-EGGS OF RANA-DYBOWSKII, Comparative biochemistry and physiology. B. Comparative biochemistry, 108(3), 1994, pp. 289-294
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.