Calcium-independent phospholipid/diolein-dependent phosphorylation of a soluble ovarian Mr 80,000 substrate protein: biochemical characteristics
| Autor: | Josephine B. Miller, Evelyn T. Maizels, Victoria Jackiw, Richard E. Cutler, Mary Hunzicker-Dunn, Lynda C. Kern, Ellen M. Carney |
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| Rok vydání: | 1990 |
| Předmět: |
Biology
Substrate Specificity Diglycerides chemistry.chemical_compound Affinity chromatography Animals Protein phosphorylation Protein kinase A Molecular Biology Polyacrylamide gel electrophoresis Phospholipids Gel electrophoresis Kinase Ovary Brain Myelin Basic Protein Rats Inbred Strains Cell Biology Phosphoproteins Molecular biology Rats Molecular Weight EGTA Biochemistry chemistry Phosphorylation Calcium Female Protein Kinases |
| Zdroj: | Biochimica et biophysica acta. 1054(3) |
| ISSN: | 0006-3002 |
| Popis: | Soluble ovarian extracts were incubated with protein kinase effectors in the presence of [ γ 32 P]ATP and proteins were separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Autoradiograms revealed phosphorylation of an ovarian M r = 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 M r = 80 000 phosphorylation was inhibited by 2·10 −7 M or greater free Ca 2+ . The ovarian M r = 80 000 substrate was distinguished from the myristoylated acidic M r = 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, phospatidylserine and 1,2-diolein. Finally, the effect of Ca 2+ on ovarian M r = 80 000 [ 32 P]phosphate content could not be accounted for by post-phosphorylation activities, or by DEAE-resolvable or hydroxylapatite-resolvable inhibitory activities. |
| Databáze: | OpenAIRE |
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