Calcium-independent phospholipid/diolein-dependent phosphorylation of a soluble ovarian Mr 80,000 substrate protein: biochemical characteristics.
Biochim Biophys Acta
; 1054(3): 285-96, 1990 Sep 24.
Article
em En
| MEDLINE
| ID: mdl-1698459
ABSTRACT
Soluble ovarian extracts were incubated with protein kinase effectors in the presence of [gamma 32P]ATP and proteins were separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Autoradiograms revealed phosphorylation of an ovarian Mr = 80,000 substrate in the presence of EGTA ([ethylenebis(oxyethylenenitrilo)]tetraacetic acid), phosphatidylserine and 1,2-diolein. In contrast to a classical response pattern to C-kinase effectors, the ovarian Mr = 80,000 phosphorylation was inhibited by 2 x 10(-7) M or greater free Ca2+. The ovarian Mr = 80,000 substrate was distinguished from the myristoylated acidic Mr = 80,000 C-kinase substrate of brain tissue on the basis of heat stability and phosphorylative response to effectors. Phosphorylation of the exogenous substrate myelin basic protein by DEAE-resolved ovarian kinase showed the variant effector dependence, maximal in the presence of EGTA, phosphatidylserine and 1,2-diolein. Finally, the effect of Ca2+ on ovarian Mr = 80,000 [32P]phosphate content could not be accounted for by post-phosphorylation activities, or by DEAE-resolvable or hydroxylapatite-resolvable inhibitory activities.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ovário
/
Fosfoproteínas
/
Proteínas Quinases
Limite:
Animals
Idioma:
En
Revista:
Biochim Biophys Acta
Ano de publicação:
1990
Tipo de documento:
Article