Evidence that the ras oncogene-encoded p21 protein induces oocyte maturation via activation of protein kinase C.
AUTOR(ES)
Chung, D L
RESUMO
The ras oncogene-encoded p21 protein is known to induce cell maturation of Xenopus laevis oocytes and malignant transformation of NIH 3T3 mouse fibroblasts. The pathways involved in oocytes and NIH 3T3 cells appear to be similar to one another. For example, in both cases, the ras p21-induced cellular events involve increased intracellular levels of the second messengers diacylglycerol and inositol phosphates, the former of which activates protein kinase C (PKC). To investigate the pathway of ras-induced oocyte maturation, we have explored the relationship between p21 protein and PKC. We show that the maturation signal from oncogenic p21 microinjected into Xenopus oocytes is completely blocked by the relatively specific PKC inhibitor CGP 41251, a staurosporine analogue that selectively inhibits PKC, but not by an inactive analogue of staurosporine, CGP 42700. Microinjection of purified PKC or of phorbol ester induces maturation of oocytes. PKC-induced maturation is inhibited by CGP 41251 but not by CGP 42700. Maturation induced by microinjected PKC is also not inhibited by two specific anti-p21 agents, the inactivating anti-p21 monoclonal antibody Y13-259 and the amino acid derivative azatyrosine. Both of these agents block p21-induced cell maturation. These results suggest that ras effects depend upon the action of PKC, whose activation is an event that occurs downstream of p21 in the maturation signal pathway.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=48580Documentos Relacionados
- Correlation of the structure of the transmembrane domain of the neu oncogene-encoded p185 protein with its function.
- Differential modulation of plasminogen activator gene expression by oncogene-encoded protein tyrosine kinases.
- Monoclonal antibodies to individual tyrosine-phosphorylated protein substrates of oncogene-encoded tyrosine kinases.
- Isolation of antibodies for phosphotyrosine by immunization with a v-abl oncogene-encoded protein.
- Insulin induction of Xenopus laevis oocyte maturation is inhibited by monoclonal antibody against p21 ras proteins.