Progesterone but not ras requires MPF for in vivo activation of MAPK and S6 KII: MAPK is an essential conexion point of both signaling pathways
- 1 August 1994
- journal article
- research article
- Published by Wiley in Journal of Cellular Biochemistry
- Vol. 55 (4), 465-476
- https://doi.org/10.1002/jcb.240550406
Abstract
Induction of mitosis in Xenopus laevis oocytes by hormones and the oncogenic ras-p21 protein has been shown to correlate with a cascade of phosphorylations of the Ser/Thr family of kinases. However, the exact hierarchy of enzymes and their mutual interdependency has not been fully elucidated yet. We have used the Xenopus laevis system to investigate the mechanism of activation of the Ser/Thr kinases cascade and their relationship. Comparison between progesterone-induced germinal vesicle breakdown (GVBD), a hallmark of mitosis in oocytes, to that triggered by ras-p21, revealed the existence of at least two independent mechanisms to activate the MAP kinase enzyme in vivo. While progesterone function is dependent of cdc2 protein kinase activity, ras-p21 is independent of this enzyme. However, both progesterone and ras-p21 converge at the MAP kinase level, and depletion of MAP kinase activity inhibits the GVBD and S6 kinase II activation induced by both progesterone and ras-p21. These results provides further evidence that MAP kinase is a critical step for regulation of the cell cycle in oocytes and a critical point where ras and progesterone signaling converge.Keywords
This publication has 52 references indexed in Scilit:
- Complexes of Ras⋅GTP with Raf-1 and Mitogen-Activated Protein Kinase KinaseScience, 1993
- cPLA2 is phosphorylated and activated by MAP kinaseCell, 1993
- The ras Oncoprotein and M-Phase ActivityScience, 1991
- ERKs: A family of protein-serine/threonine kinases that are activated and tyrosine phosphorylated in response to insulin and NGFCell, 1991
- Activation of p34cdc2 kinase by cyclin A.The Journal of cell biology, 1991
- Universal control mechanism regulating onset of M-phaseNature, 1990
- Differential inhibition of nerve growth factor responses by purine analogues: correlation with inhibition of a nerve growth factor-activated protein kinase.The Journal of cell biology, 1989
- Characterization of a mitogen‐activated, Ca2+‐sensitive microtubule‐associated protein‐2 kinaseEuropean Journal of Biochemistry, 1989
- 6-Dimethylaminopurine (6-DMAP), a reversible inhibitor of the transition to metaphase during the first meiotic cell division of the mouse oocyteDevelopmental Biology, 1989
- Oncogenic ras protein induces meiotic maturation of amphibian oocytes in the presence of protein synthesis inhibitorsFEBS Letters, 1988