Mitosis-specific monoclonal antibodies block cleavage in amphibian embryos.

Davis, Frances M.; Wright, David; Penkala, Joseph E.; Rao, Potu N.

doi:10.1247/csf.14.271

Cited by 16 publications

(7 citation statements)

References 18 publications

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“…In the interphase-arrested extracts, H1 kinase activity remained low, the tyrosine-phosphorylated form of Cdc2 accumulated, cyclin B2 remained hypophosphorylated, Cdc25C did not undergo hyperphosphorylation, and nuclei continued to enlarge. In addition, M-phasespecific phosphoproteins were not detected with the MPM-2 antibody (Davis et al, 1989;Kuang et al, 1994;our unpublished results), providing further support that these extracts remained in interphase. The interphase arrest persisted for at least 130 min, even though control extracts had completed at least two cell cycles by this time.…”

Section: Discussion P42mapk Activation Inhibits Entry Into M-phase Inmentioning

confidence: 80%

Activation of the p42 Mitogen-activated Protein Kinase Pathway Inhibits Cdc2 Activation and Entry into M-Phase in CyclingXenopusEgg Extracts

Bitangcol

Chau

Stadnick

et al. 1998

MBoC

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We have added constitutively active MAP kinase/ERK kinase (MEK), an activator of the mitogen-activated protein kinase (MAPK) signaling pathway, to cycling Xenopus egg extracts at various times during the cell cycle. p42MAPK activation during entry into M-phase arrested the cell cycle in metaphase, as has been shown previously. Unexpectedly, p42MAPK activation during interphase inhibited entry into M-phase. In these interphase-arrested extracts, H1 kinase activity remained low, Cdc2 was tyrosine phosphorylated, and nuclei continued to enlarge. The interphase arrest was overcome by recombinant cyclin B. In other experiments, p42MAPK activation by MEK or by Mos inhibited Cdc2 activation by cyclin B. PD098059, a specific inhibitor of MEK, blocked the effects of MEK(QP) and Mos. Mos-induced activation of p42MAPK did not inhibit DNA replication. These results indicate that, in addition to the established role of p42MAPK activation in M-phase arrest, the inappropriate activation of p42MAPK during interphase prevents normal entry into M-phase.

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Section: Discussion P42mapk Activation Inhibits Entry Into M-phase Inmentioning

confidence: 80%

Activation of the p42 Mitogen-activated Protein Kinase Pathway Inhibits Cdc2 Activation and Entry into M-Phase in CyclingXenopusEgg Extracts

Bitangcol

Chau

Stadnick

et al. 1998

MBoC

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“…Second, the interaction either between Pin1 and its interacting proteins or MPM-2 and its antigens is dependent on mitosis-specific phosphorylation of the target proteins (Davis et al 1983;Westendorf et al 1994; this study). Third, both inhibit cell cycle progression in Xenopus embryos and entry into mitosis in Xenopus extracts (this study, Davis et al 1989;Kuang et al 1989). Fourth, Pin1 is highly conserved in all eukaryotic cells so far examined, including plants, yeast, Aspergillus, and vertebrates, as is the case for the MPM-2 epitope (Davis et al 1983;Vandre et al 1986;Hirano and Mitchison 1991;Kuang et al 1994;Westendorf et al 1994;Ye et al 1995;Matsumoto-Taniura et al 1996).…”

Section: The Relationship Between Pin1 and Mpm-2 Antigensmentioning

confidence: 76%

The essential mitotic peptidyl-prolyl isomerase Pin1 binds and regulates mitosis-specific phosphoproteins

Shen¹,

Stukenberg²,

Kirschner³

et al. 1998

Genes & Development

326

317

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Phosphorylation of mitotic proteins on the Ser/Thr-Pro motifs has been shown to play an important role in regulating mitotic progression. Pin1 is a novel essential peptidyl-prolyl isomerase (PPIase) that inhibits entry into mitosis and is also required for proper progression through mitosis, but its substrate(s) and function(s) remain to be determined. Here we report that in both human cells and Xenopus extracts, Pin1 interacts directly with a subset of mitotic phosphoproteins on phosphorylated Ser/Thr-Pro motifs in a phosphorylation-dependent and mitosis-specific manner. Many of these Pin1-binding proteins are also recognized by the monoclonal antibody MPM-2, and they include the important mitotic regulators Cdc25, Myt1, Wee1, Plk1, and Cdc27. The importance of this Pin1 interaction was tested by constructing two Pin1 active site point mutants that fail to bind a phosphorylated Ser/Thr-Pro motif in mitotic phosphoproteins. Wild-type, but not mutant, Pin1 inhibits both mitotic division in Xenopus embryos and entry into mitosis in Xenopus extracts. We have examined the interaction between Pin1 and Cdc25 in detail. Pin1 not only binds the mitotic form of Cdc25 on the phosphorylation sites important for its activity in vitro and in vivo, but it also inhibits its activity, offering one explanation for the ability of Pin1 to inhibit mitotic entry. In a separate paper, we have shown that Pin1 is a phosphorylation-dependent PPIase that can recognize specifically the phosphorylated Ser/Thr-Pro bonds present in mitotic phosphoproteins. Thus, Pin1 likely acts as a general regulator of mitotic proteins that have been phosphorylated by Cdc2 and other mitotic kinases.

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“…the microtubule-associated proteins 1 and 4 (MAP1 and MAP4) (39,40), DNA topoisomerase II (41), Xenopus CDC25 (42), Xenopus wee1-like kinase, and myt1 (43). Microinjection of MPM-2 antibodies into fertilized Xenopus eggs inhibits both the onset and completion of mitosis, indicating the importance of this mitosis-specific phosphorylation (44,45).…”

Section: Fig 2 Facscan Analysis Of Mdck Cells After Mimosine or Nocmentioning

confidence: 99%

Modification of the E-cadherin-Catenin Complex in Mitotic Madin-Darby Canine Kidney Epithelial Cells

Bauer

Lickert

Kemler

et al. 1998

Journal of Biological Chemistry

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One of the hallmarks of polarized epithelial cells undergoing mitosis is their rounded morphology. This phenotype correlates with a reduced cell-substratum adhesion, apparently caused by a modulation of integrin function. However, it is still unclear whether the cadherin-mediated cell-cell adhesion is affected as well. To address this question, the cadherin complex was analyzed in different cell cycle stages of Madin-Darby canine kidney cells. By immunofluorescence, mitotic Madin-Darby canine kidney cells showed an increased staining of E-cadherin and the catenins (␣-catenin, ␤-catenin, plakoglobin, p120 ctn ) in the cytosol, suggesting a reorganization of the cadherin-catenin complex during mitosis. Biochemical analysis revealed that the overall amount of these components, as well as the proportion of the complex associated with the actin cytoskeleton, remained unchanged in mitotic cells. However, we found evidence for an internalization of E-cadherin during mitosis. In addition, the cadherincatenin complex was analyzed for mitosis-specific changes in phosphorylation. We report a decrease in the tyrosine phosphorylation of ␤-catenin, plakoglobin, and p120 ctn during mitosis. Moreover, we observed a mitosisspecific Ser/Thr-phosphorylation of p120 ctn , as detected by the MPM-2 antibody. Hence, the cadherin/catenin complex is a target for different posttranslational modifications during mitosis, which may also have a profound impact on cadherin-mediated cell-cell adhesion.

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Mitosis-specific monoclonal antibodies block cleavage in amphibian embryos.

Cited by 16 publications

References 18 publications

Activation of the p42 Mitogen-activated Protein Kinase Pathway Inhibits Cdc2 Activation and Entry into M-Phase in CyclingXenopusEgg Extracts

Activation of the p42 Mitogen-activated Protein Kinase Pathway Inhibits Cdc2 Activation and Entry into M-Phase in CyclingXenopusEgg Extracts

The essential mitotic peptidyl-prolyl isomerase Pin1 binds and regulates mitosis-specific phosphoproteins

Modification of the E-cadherin-Catenin Complex in Mitotic Madin-Darby Canine Kidney Epithelial Cells

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