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.
Maintenance of G2 arrest in the Xenopus oocyte: a role for 14-3-3-mediated inhibition of Cdc25 nuclear import.
Yang J
,
Winkler K
,
Yoshida M
,
Kornbluth S
.
???displayArticle.abstract??? Cdc2-cyclin B1 in the G2-arrested Xenopus oocyte is held inactive by phosphorylation of Cdc2 at two negative regulatory sites, Thr14 and Tyr15. Upon treatment with progesterone, these sites are dephosphorylated by the dual specificity phosphatase, Cdc25, leading to Cdc2-cyclin B1 activation. Whereas maintenance of the G2 arrest depends upon preventing Cdc25-induced Cdc2 dephosphorylation, the mechanisms responsible for keeping Cdc25 in check in these cells have not yet been described. Here we report that Cdc25 in the G2-arrested oocyte is bound to 14-3-3 proteins and that progesterone treatment abrogates this binding. We demonstrate that Cdc25, apparently statically localized in the cytoplasm, is actually capable of shuttling in and out of the oocytenucleus. Binding of 14-3-3 protein markedly reduces the nuclear import rate of Cdc25, allowing nuclear export mediated by a nuclear export sequence present in the N-terminus of Cdc25 to predominate. If 14-3-3 binding to Cdc25 is prevented while nuclear export is inhibited, the coordinate nuclear accumulation of Cdc25 and Cdc2-cyclin B1 facilitates their mutual activation, thereby promoting oocyte maturation.
Atherton-Fessler,
Cell cycle regulation of the p34cdc2 inhibitory kinases.
1994, Pubmed,
Xenbase
Atherton-Fessler,
Cell cycle regulation of the p34cdc2 inhibitory kinases.
1994,
Pubmed
,
Xenbase
Bogerd,
Protein sequence requirements for function of the human T-cell leukemia virus type 1 Rex nuclear export signal delineated by a novel in vivo randomization-selection assay.
1996,
Pubmed
Coleman,
Cdc2 regulatory factors.
1994,
Pubmed
Cyert,
Regulation of MPF activity in vitro.
1988,
Pubmed
,
Xenbase
Dunphy,
The cdc25 protein contains an intrinsic phosphatase activity.
1991,
Pubmed
Enoch,
Mutation of fission yeast cell cycle control genes abolishes dependence of mitosis on DNA replication.
1990,
Pubmed
Enoch,
Fission yeast genes involved in coupling mitosis to completion of DNA replication.
1992,
Pubmed
Fornerod,
CRM1 is an export receptor for leucine-rich nuclear export signals.
1997,
Pubmed
,
Xenbase
Furnari,
Cdc25 mitotic inducer targeted by chk1 DNA damage checkpoint kinase.
1997,
Pubmed
Gautier,
Cyclin B in Xenopus oocytes: implications for the mechanism of pre-MPF activation.
1991,
Pubmed
,
Xenbase
Gautier,
cdc25 is a specific tyrosine phosphatase that directly activates p34cdc2.
1991,
Pubmed
,
Xenbase
Görlich,
Isolation of a protein that is essential for the first step of nuclear protein import.
1994,
Pubmed
,
Xenbase
Görlich,
Distinct functions for the two importin subunits in nuclear protein import.
1995,
Pubmed
,
Xenbase
Hagting,
MPF localization is controlled by nuclear export.
1998,
Pubmed
Hoffmann,
Phosphorylation and activation of human cdc25-C by cdc2--cyclin B and its involvement in the self-amplification of MPF at mitosis.
1993,
Pubmed
,
Xenbase
Izumi,
Phosphorylation and activation of the Xenopus Cdc25 phosphatase in the absence of Cdc2 and Cdk2 kinase activity.
1995,
Pubmed
,
Xenbase
Izumi,
Periodic changes in phosphorylation of the Xenopus cdc25 phosphatase regulate its activity.
1992,
Pubmed
,
Xenbase
Jin,
Nuclear localization of cyclin B1 controls mitotic entry after DNA damage.
1998,
Pubmed
Kanki,
Progression from meiosis I to meiosis II in Xenopus oocytes requires de novo translation of the mosxe protooncogene.
1991,
Pubmed
,
Xenbase
Kobayashi,
On the synthesis and destruction of A- and B-type cyclins during oogenesis and meiotic maturation in Xenopus laevis.
1991,
Pubmed
,
Xenbase
Kornbluth,
Membrane localization of the kinase which phosphorylates p34cdc2 on threonine 14.
1994,
Pubmed
,
Xenbase
Kosako,
Requirement for the MAP kinase kinase/MAP kinase cascade in Xenopus oocyte maturation.
1994,
Pubmed
,
Xenbase
Kumagai,
14-3-3 proteins act as negative regulators of the mitotic inducer Cdc25 in Xenopus egg extracts.
1998,
Pubmed
,
Xenbase
Kumagai,
The Xenopus Chk1 protein kinase mediates a caffeine-sensitive pathway of checkpoint control in cell-free extracts.
1998,
Pubmed
,
Xenbase
Kumagai,
Regulation of the cdc25 protein during the cell cycle in Xenopus extracts.
1992,
Pubmed
,
Xenbase
Kumagai,
Purification and molecular cloning of Plx1, a Cdc25-regulatory kinase from Xenopus egg extracts.
1996,
Pubmed
,
Xenbase
Kunkel,
Rapid and efficient site-specific mutagenesis without phenotypic selection.
1987,
Pubmed
Kunkel,
Rapid and efficient site-specific mutagenesis without phenotypic selection.
1985,
Pubmed
Lew,
Regulatory roles of cyclin dependent kinase phosphorylation in cell cycle control.
1996,
Pubmed
Li,
Nuclear localization of cyclin B1 mediates its biological activity and is regulated by phosphorylation.
1997,
Pubmed
,
Xenbase
Li,
Requirement for phosphorylation of cyclin B1 for Xenopus oocyte maturation.
1995,
Pubmed
,
Xenbase
Lopez-Girona,
Nuclear localization of Cdc25 is regulated by DNA damage and a 14-3-3 protein.
1999,
Pubmed
Masui,
Cytoplasmic control of nuclear behavior during meiotic maturation of frog oocytes.
1971,
Pubmed
Meijer,
Biochemical and cellular effects of roscovitine, a potent and selective inhibitor of the cyclin-dependent kinases cdc2, cdk2 and cdk5.
1997,
Pubmed
,
Xenbase
Millar,
The cdc25 M-phase inducer: an unconventional protein phosphatase.
1992,
Pubmed
Mueller,
Myt1: a membrane-associated inhibitory kinase that phosphorylates Cdc2 on both threonine-14 and tyrosine-15.
1995,
Pubmed
,
Xenbase
Murakami,
Analysis of the early embryonic cell cycles of Xenopus; regulation of cell cycle length by Xe-wee1 and Mos.
1998,
Pubmed
,
Xenbase
Nebreda,
The c-mos proto-oncogene protein kinase turns on and maintains the activity of MAP kinase, but not MPF, in cell-free extracts of Xenopus oocytes and eggs.
1993,
Pubmed
,
Xenbase
Neville,
The importin-beta family member Crm1p bridges the interaction between Rev and the nuclear pore complex during nuclear export.
1997,
Pubmed
Ossareh-Nazari,
Evidence for a role of CRM1 in signal-mediated nuclear protein export.
1997,
Pubmed
Palmer,
A link between MAP kinase and p34(cdc2)/cyclin B during oocyte maturation: p90(rsk) phosphorylates and inactivates the p34(cdc2) inhibitory kinase Myt1.
1998,
Pubmed
,
Xenbase
Peng,
Mitotic and G2 checkpoint control: regulation of 14-3-3 protein binding by phosphorylation of Cdc25C on serine-216.
1997,
Pubmed
Qian,
Activated polo-like kinase Plx1 is required at multiple points during mitosis in Xenopus laevis.
1998,
Pubmed
,
Xenbase
Sagata,
The product of the mos proto-oncogene as a candidate "initiator" for oocyte maturation.
1989,
Pubmed
,
Xenbase
Sanchez,
Conservation of the Chk1 checkpoint pathway in mammals: linkage of DNA damage to Cdk regulation through Cdc25.
1997,
Pubmed
Seki,
Chromosome condensation caused by loss of RCC1 function requires the cdc25C protein that is located in the cytoplasm.
1992,
Pubmed
Shibuya,
Oncogenic ras triggers the activation of 42-kDa mitogen-activated protein kinase in extracts of quiescent Xenopus oocytes.
1992,
Pubmed
,
Xenbase
Shibuya,
Mos induces the in vitro activation of mitogen-activated protein kinases in lysates of frog oocytes and mammalian somatic cells.
1993,
Pubmed
,
Xenbase
Smythe,
Systems for the study of nuclear assembly, DNA replication, and nuclear breakdown in Xenopus laevis egg extracts.
1991,
Pubmed
,
Xenbase
Smythe,
Coupling of mitosis to the completion of S phase in Xenopus occurs via modulation of the tyrosine kinase that phosphorylates p34cdc2.
1992,
Pubmed
,
Xenbase
Stade,
Exportin 1 (Crm1p) is an essential nuclear export factor.
1997,
Pubmed
Strausfeld,
Dephosphorylation and activation of a p34cdc2/cyclin B complex in vitro by human CDC25 protein.
1991,
Pubmed
Swenson,
Formation of gap junctions by expression of connexins in Xenopus oocyte pairs.
1989,
Pubmed
,
Xenbase
Toyoshima,
Nuclear export of cyclin B1 and its possible role in the DNA damage-induced G2 checkpoint.
1998,
Pubmed
Wolff,
Leptomycin B is an inhibitor of nuclear export: inhibition of nucleo-cytoplasmic translocation of the human immunodeficiency virus type 1 (HIV-1) Rev protein and Rev-dependent mRNA.
1997,
Pubmed
Yang,
Control of cyclin B1 localization through regulated binding of the nuclear export factor CRM1.
1998,
Pubmed
,
Xenbase
Zeng,
Replication checkpoint requires phosphorylation of the phosphatase Cdc25 by Cds1 or Chk1.
1998,
Pubmed
