Regulation of tyrosine-specific kinase activity at fertilization.
Dev Biol
; 105(1): 137-43, 1984 Sep.
Article
em En
| MEDLINE
| ID: mdl-6432606
ABSTRACT
The sea urchin egg contains a protein kinase which phosphorylates tyrosine residues of endogenous membrane proteins as well as synthetic peptide substrates. Fertilization results in an increase in tyrosine kinase activity which first becomes apparent 20-30 min postinsemination and continues throughout the early cleavage stages. This effect can be duplicated by treating unfertilized eggs with the calcium ionophore A23187. The kinase activity begins to increase about 20 min after addition of the ionophore and continues to increase for at least 1 hr. Both the time course and the extent of kinase activity in ionophore treated eggs closely resemble the effects of fertilization. The concentration of ionophore necessary to induce the increase in enzyme activity (2-5 microM) is also effective in inducing the cortical reaction. Neither A23187 nor calcium has a significant effect on the kinase activity of egg homogenates solubilized in NP40, suggesting that the ionophore affects tyrosine phosphorylation indirectly, possibly acting through other calcium-sensitive enzymes.
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Base de dados:
MEDLINE
Assunto principal:
Óvulo
/
Proteínas Quinases
/
Fertilização
Limite:
Animals
Idioma:
En
Revista:
Dev Biol
Ano de publicação:
1984
Tipo de documento:
Article