...Enrico Maria Daldello; Xuan G. Luong; Cai-Rong Yang; Jonathan Kuhn; Marco Conti ABSTRACT Cyclins associate with cyclin-dependent serine/threonine kinase 1 (CDK1) to generate the M phase-promoting factor (MPF) activity essential for progression through mitosis and meiosis. Although cyclin B1 (CCNB1...

... cascade, for conversion of inactive pre-MPF into active MPF. We have found that Myt1 is likely to be the Mos target in this process, as Mos interacts with Myt1 in oocyte extracts and Mos triggers Myt1 phosphorylation on some sites in vivo, even in the absence of MAPK activation. We propose that Mos...

... the downstream targets of activated PKA remain unknown, neither the synthesis of new proteins nor the activation of MAPKs (mitogen-activated protein kinases) appeared to be required for GVBD after 5-HT stimulation. Alternatively, pre-incubation in roscovitine, an inhibitor of maturation-promoting factor (MPF...

... from MPF activation. We show that MAP kinase activation can be suppressed by treatment with geldanamycin or by overexpression of the MAP kinase phosphatase Pyst1. A transient and low-level early activation of MAP kinase increases the efficiency of cell cycle activation later on, when MAP kinase...

...Alex McDougall; Mark Levasseur ABSTRACT We have investigated the relationship between the sperm-triggered Ca 2+ oscillations and the activities of two cell cycle kinases (MPF activity and MAP kinase activity) at fertilisation of Ascidiella aspersa oocytes. Maturation Promoting Factor (MPF) activity...

... amplitude were generated at the time of the phase 3 oscillations. Biochemical characterization of Maturation Promoting Factor (MPF) in ascidian oocytes led to the identification of a Cdc2-like kinase activity. Using p13 suc1 -sepharose as a reagent to precipitate the MPF complex, a 67 kDa (67×10 3 M r...

... with the microtubules of the sperm aster in fertilized eggs, or an extensive activation aster in activated eggs. Neither assembly and organization, nor disassembly of the cortical microtubules coincided with MPF activation during mitosis. However, cycloheximide or 6-dimethyl-aminopurine, which arrest fertilized eggs...

... protein synthesis and microfilaments but microtubules are not implicated in this process. In addition, the effects on the MV pattern of the maturation or mitosis promoting factor (MPF) were tested. Injection of MPF into eggs at different times during the first division cycle nearly always induced...

...Andrew D. Johnson; L. Dennis Smith ABSTRACT Entry into M phase in the eukaryotic cell cycle is controlled by the oscillating activity of MPF. The active component of MPF is now known to be the p34 cdc2 protein kinase originally found in yeast. The p34 cdc2 protein kinase displays a characteristic M...

...L. Dennis Smith 21 09 1989 © 1989 by Company of Biologists 1989 oocyte maturation induction transmembrane signaling regulation cell cycle MPF amphibia The induction of oocyte maturation is known to involve an initial action of agonists at the oocyte surface...

...André Picard; Jean-Claude Labbé; Marcel Dorée Oocytes arrested at the first meiotic prophase re-initiate meiosis under the influence of a variety of signals, including hormones. These signals are thought to act indirectly to produce a maturation-promoting factor (MPF) which triggers transition...

... increase in protein synthesis. Second, the injection of globin mRNA into stage-4 oocytes increases total protein synthesis two to three fold, but has no effect on S6 phosphorylation. Third, when the injection of globin mRNA into stage-4 oocytes is followed by an injection of MPF, a dramatic increase in S6...