Abstract
We have identified the intracellular detoxification enzyme, glutathione- S-transferase (GST), as a potent inhibitor of the activation of jun by its kinase, jun-N-terminal kinase (JNK), in vitro. All three major isozymes (α, μ, and π) bind to JNK-jun complexes and inhibit activation of jun by JNK. We now find that GST inhibits JNK-induced oocyte maturation in vivo and strongly inhibits oocyte maturation induced by oncogenic ras-p21 protein, but not by insulin-activated normal cellular p21 protein. These results correlate with the finding that oncogenic, but not insulin-activated normal, p21 induces high levels of activated JNK. GST also strongly blocks induction of oocyte maturation by protein kinase C (PKC) which is a critical downstream target of oncogenic but not normal ras-p21. Thus, we have established a new function for GST as a potent physiological inhibitor of the ras-JNK-jun pathway.
Original language | English |
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Pages (from-to) | 57-64 |
Number of pages | 8 |
Journal | Annals of Clinical and Laboratory Science |
Volume | 30 |
Issue number | 1 |
State | Published - Jan 2000 |
Keywords
- Glutathione-S-transferase
- Oocyte maturation
- Protein kinase C
- jun
- jun kinase
- ras-p21