Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
???displayArticle.abstract???
Using cytostatic factor metaphase II-arrested extracts as a model system, we show that protein phosphatase 1 is regulated during early embryonic cell cycles in Xenopus. Phosphatase 1 activity peaks during interphase and decreases shortly before the onset of mitosis. A second peak of activity appears in mitosis at about the same time that cdc2 becomes active. If extracts are inhibited in S-phase with aphidicolin, then phosphatase 1 activity remains high. The activity of phosphatase 1 appears to determine the timing of exit from S-phase and entry into M-phase; inhibition of phosphatase 1 by the specific inhibitor, inhibitor 2 (Inh-2), causes premature entry into mitosis, whereas exogenously added phosphatase 1 lengthens the interphase period. Analysis of DNA synthesis in extracts treated with Inh-2, but lacking the A- and B-type cyclins, shows that phosphatase 1 is also required for the process of DNA replication. These data indicate that phosphatase 1 is a component of the signaling pathway that ensures that M-phase is not initiated until DNA synthesis is complete.
Amon,
Regulation of p34CDC28 tyrosine phosphorylation is not required for entry into mitosis in S. cerevisiae.
1992, Pubmed,
Xenbase
Amon,
Regulation of p34CDC28 tyrosine phosphorylation is not required for entry into mitosis in S. cerevisiae.
1992,
Pubmed
,
Xenbase Andres,
Purification and characterization of a novel protein phosphatase highly specific for ribosomal protein S6.
1989,
Pubmed
,
Xenbase Axton,
One of the protein phosphatase 1 isoenzymes in Drosophila is essential for mitosis.
1990,
Pubmed Bandara,
Cyclin A and the retinoblastoma gene product complex with a common transcription factor.
1991,
Pubmed Blow,
Initiation of DNA replication in nuclei and purified DNA by a cell-free extract of Xenopus eggs.
1986,
Pubmed
,
Xenbase Booher,
Involvement of a type 1 protein phosphatase encoded by bws1+ in fission yeast mitotic control.
1989,
Pubmed Booher,
The fission yeast cdc2/cdc13/suc1 protein kinase: regulation of catalytic activity and nuclear localization.
1989,
Pubmed Brautigan,
Cell cycle oscillation of phosphatase inhibitor-2 in rat fibroblasts coincident with p34cdc2 restriction.
1990,
Pubmed Cohen,
The structure and regulation of protein phosphatases.
1989,
Pubmed Cyert,
Regulation of MPF activity in vitro.
1988,
Pubmed
,
Xenbase Dasso,
Completion of DNA replication is monitored by a feedback system that controls the initiation of mitosis in vitro: studies in Xenopus.
1990,
Pubmed
,
Xenbase Dent,
The molecular mechanism by which insulin stimulates glycogen synthesis in mammalian skeletal muscle.
1990,
Pubmed Doonan,
The bimG gene of Aspergillus nidulans, required for completion of anaphase, encodes a homolog of mammalian phosphoprotein phosphatase 1.
1989,
Pubmed Draetta,
Activation of cdc2 protein kinase during mitosis in human cells: cell cycle-dependent phosphorylation and subunit rearrangement.
1988,
Pubmed Draetta,
Cdc2 protein kinase is complexed with both cyclin A and B: evidence for proteolytic inactivation of MPF.
1989,
Pubmed Ducommun,
cdc2 phosphorylation is required for its interaction with cyclin.
1991,
Pubmed
,
Xenbase Dunphy,
The cdc25 protein contains an intrinsic phosphatase activity.
1991,
Pubmed Dunphy,
The Xenopus cdc2 protein is a component of MPF, a cytoplasmic regulator of mitosis.
1988,
Pubmed
,
Xenbase Dunphy,
Fission yeast p13 blocks mitotic activation and tyrosine dephosphorylation of the Xenopus cdc2 protein kinase.
1989,
Pubmed
,
Xenbase Evans,
Cyclin: a protein specified by maternal mRNA in sea urchin eggs that is destroyed at each cleavage division.
1983,
Pubmed Félix,
Cdc2 H1 kinase is negatively regulated by a type 2A phosphatase in the Xenopus early embryonic cell cycle: evidence from the effects of okadaic acid.
1990,
Pubmed
,
Xenbase Foulkes,
In vivo actions of protein phosphatase inhibitor-2 in Xenopus oocytes.
1982,
Pubmed
,
Xenbase Gautier,
cdc25 is a specific tyrosine phosphatase that directly activates p34cdc2.
1991,
Pubmed
,
Xenbase Gautier,
Purified maturation-promoting factor contains the product of a Xenopus homolog of the fission yeast cell cycle control gene cdc2+.
1988,
Pubmed
,
Xenbase Gautier,
Cyclin is a component of maturation-promoting factor from Xenopus.
1990,
Pubmed
,
Xenbase Gautier,
Dephosphorylation and activation of Xenopus p34cdc2 protein kinase during the cell cycle.
1989,
Pubmed
,
Xenbase Glotzer,
Cyclin is degraded by the ubiquitin pathway.
1991,
Pubmed
,
Xenbase Goris,
Okadaic acid, a specific protein phosphatase inhibitor, induces maturation and MPF formation in Xenopus laevis oocytes.
1989,
Pubmed
,
Xenbase Gould,
Phosphorylation at Thr167 is required for Schizosaccharomyces pombe p34cdc2 function.
1991,
Pubmed Gould,
Tyrosine phosphorylation of the fission yeast cdc2+ protein kinase regulates entry into mitosis.
1989,
Pubmed Healy,
CDC55, a Saccharomyces cerevisiae gene involved in cellular morphogenesis: identification, characterization, and homology to the B subunit of mammalian type 2A protein phosphatase.
1991,
Pubmed Ingebritsen,
The protein phosphatases involved in cellular regulation. 2. Glycogen metabolism.
1983,
Pubmed Kinoshita,
Distinct, essential roles of type 1 and 2A protein phosphatases in the control of the fission yeast cell division cycle.
1990,
Pubmed Kumagai,
The cdc25 protein controls tyrosine dephosphorylation of the cdc2 protein in a cell-free system.
1991,
Pubmed
,
Xenbase Lavoinne,
Purification and characterisation of the insulin-stimulated protein kinase from rabbit skeletal muscle; close similarity to S6 kinase II.
1991,
Pubmed
,
Xenbase Lee,
Cell cycle control genes in fission yeast and mammalian cells.
1988,
Pubmed Lee,
cdc25+ encodes a protein phosphatase that dephosphorylates p34cdc2.
1992,
Pubmed
,
Xenbase Lee,
INH, a negative regulator of MPF, is a form of protein phosphatase 2A.
1991,
Pubmed
,
Xenbase Lohka,
Induction of nuclear envelope breakdown, chromosome condensation, and spindle formation in cell-free extracts.
1985,
Pubmed
,
Xenbase Lorca,
An okadaic acid-sensitive phosphatase negatively controls the cyclin degradation pathway in amphibian eggs.
1991,
Pubmed
,
Xenbase Lundgren,
mik1 and wee1 cooperate in the inhibitory tyrosine phosphorylation of cdc2.
1991,
Pubmed Minshull,
The A- and B-type cyclin associated cdc2 kinases in Xenopus turn on and off at different times in the cell cycle.
1990,
Pubmed
,
Xenbase Moreno,
Regulation of p34cdc2 protein kinase during mitosis.
1989,
Pubmed Morla,
Reversible tyrosine phosphorylation of cdc2: dephosphorylation accompanies activation during entry into mitosis.
1989,
Pubmed Murray,
Cyclin synthesis drives the early embryonic cell cycle.
1989,
Pubmed
,
Xenbase Murray,
Dominoes and clocks: the union of two views of the cell cycle.
1989,
Pubmed Ohkura,
The fission yeast dis2+ gene required for chromosome disjoining encodes one of two putative type 1 protein phosphatases.
1989,
Pubmed Parker,
Cyclin promotes the tyrosine phosphorylation of p34cdc2 in a wee1+ dependent manner.
1991,
Pubmed Picard,
Involvement of protein phosphatases 1 and 2A in the control of M phase-promoting factor activity in starfish.
1989,
Pubmed Picard,
Okadaic acid mimics a nuclear component required for cyclin B-cdc2 kinase microinjection to drive starfish oocytes into M phase.
1991,
Pubmed
,
Xenbase Picking,
Fluorescence studies on the interaction of inhibitor 2 and okadaic acid with the catalytic subunit of type 1 phosphoprotein phosphatases.
1991,
Pubmed Pines,
Human cyclins A and B1 are differentially located in the cell and undergo cell cycle-dependent nuclear transport.
1991,
Pubmed Ruediger,
Constant expression and activity of protein phosphatase 2A in synchronized cells.
1991,
Pubmed Russell,
Negative regulation of mitosis by wee1+, a gene encoding a protein kinase homolog.
1987,
Pubmed Russell,
cdc25+ functions as an inducer in the mitotic control of fission yeast.
1986,
Pubmed Shenolikar,
Protein phosphatases: recent progress.
1991,
Pubmed Simanis,
The cell cycle control gene cdc2+ of fission yeast encodes a protein kinase potentially regulated by phosphorylation.
1986,
Pubmed Solomon,
Role of phosphorylation in p34cdc2 activation: identification of an activating kinase.
1992,
Pubmed
,
Xenbase Solomon,
Cyclin activation of p34cdc2.
1990,
Pubmed
,
Xenbase Sorger,
S-phase feedback control in budding yeast independent of tyrosine phosphorylation of p34cdc28.
1992,
Pubmed
,
Xenbase Standart,
Cyclin synthesis, modification and destruction during meiotic maturation of the starfish oocyte.
1987,
Pubmed Swenson,
The clam embryo protein cyclin A induces entry into M phase and the resumption of meiosis in Xenopus oocytes.
1986,
Pubmed
,
Xenbase Tang,
Molecular cloning and expression of the regulatory (RG1) subunit of the glycogen-associated protein phosphatase.
1991,
Pubmed Tung,
The catalytic subunits of protein phosphatase-1 and protein phosphatase 2A are distinct gene products.
1984,
Pubmed Walker,
Role for cyclin A in the dependence of mitosis on completion of DNA replication.
1991,
Pubmed
,
Xenbase
