Fertilization results in increased tyrosine phosphorylation of egg proteins.

摘要: The sea urchin egg contains one or more tyrosine-specific protein kinase(s) which are active during the response of to sperm fusion. Fertilization results in an 8-fold increase relative incorporation [32P]orthophosphate into phosphotyrosine as compared phosphoserine and phosphothreonine. Under defined vitro conditions, plasma membranes from fertilized eggs incorporated 5-10-fold phosphate tyrosine than unfertilized eggs. Analysis phosphorylated membrane proteins by polyacrylamide gel electrophoresis demonstrated that at least four were actively Of these, a closely spaced doublet approximately 120 kDa was found contain phosphotyrosine. properties kinase studied using artificial peptide substrate. enzyme is membrane-bound enriched membrane. Enzyme activity homogenates increased 2- 4-fold, respectively, early 20 min, post-insemination. These suggest fertilization-dependent may play role onset embryonic development.