The PR55 and PR65 Subunits of Protein Phosphatase 2A from Xenopus laevis. Molecular Cloning and Developmental Regulation of Expression

Bosch, Mariette; Cayla, Xavier; C, Van Hoof; Hemmings, BA; Ozon, René; Merlevede, Wilfried; Goris, Jozef

doi:10.1111/j.1432-1033.1995.tb20653.x

Cited by 34 publications

(25 citation statements)

References 66 publications

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“…Cyclin B1 and ARPP19 antibodies were described respectively by (Frank-Vaillant et al, 1999) and (Dulubova et al, 2001). Antibodies against PP2A-A and PP2A-C subunits were generated as described (Bosch et al, 1995). Gwl antibodies were raised by immunizing rabbits with peptides corresponding to residues 17-31 and 863-876 of Xenopus Gwl (Covalab, France).…”

Section: Antibodies and Western Blot Analysismentioning

confidence: 99%

The phosphorylation of ARPP19 by Greatwall renders the autoamplification of MPF independent of PKA in Xenopus oocytes

Dupré

Buffin

Roustan

et al. 2013

Journal of Cell Science

102

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Entry into mitosis or meiosis relies on the coordinated action of kinases and phosphatases that ultimately leads to the activation of Cyclin B-Cdk1, also called MPF for M-phase promoting factor. Vertebrate oocytes are blocked in prophase of the first meiotic division, an arrest tightly controlled by a high PKA activity. Reentry into meiosis depends on Cdk1 activation that obeys a two steps mechanism: a catalytic amount of Cdk1 is generated in a PKA and protein synthesis-dependent manner; then a regulatory network called MPF auto-amplification loop is initiated. This second step is independent of PKA and protein synthesis. However, none of the molecular components of the auto-amplification loop identified so far acts independently of PKA. Therefore, the protein rendering this process independent of PKA in oocytes remains unknown. Using a physiological intact cell system, the Xenopus oocyte, we show that the phosphorylation of ARPP19 at S67 by the Greatwall kinase promotes its binding to the PP2A-B55 δ phosphatase, thus inhibiting its activity. This process is controlled by Cdk1 and plays an essential role within the Cdk1 auto-amplification loop for entry into the first meiotic division. Moreover, once phosphorylated by Greatwall, ARPP19 escapes the negative regulation exerted by PKA. It also promotes MPF activation independently of protein synthesis, provided a small amount of Mos is present. Taken together, these findings reveal that PP2A-B55δ, Greatwall and ARPP19 are not only required for entry into meiotic divisions, but are also pivotal effectors within the Cdk1 auto-regulatory loop responsible for its independence toward PKA negative control.

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Section: Antibodies and Western Blot Analysismentioning

confidence: 99%

The phosphorylation of ARPP19 by Greatwall renders the autoamplification of MPF independent of PKA in Xenopus oocytes

Dupré

Buffin

Roustan

et al. 2013

Journal of Cell Science

102

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“…Protocol for purification of PP2A proteins (trimeric PP2A1 and PP2A-A or B␣ subunits) from pig brain was adapted from Waelkens et al (1987). Characterization of PP2A antibodies (polyclonal guinea pig anti-A, or anti-B and anti-C subunits) has been described previously (Bosch et et al, 1995).…”

Section: Methodsmentioning

confidence: 99%

Use of Penetrating Peptides Interacting with PP1/PP2A Proteins As a General Approach for a Drug Phosphatase Technology

Guergnon¹,

Dessauge²,

Domínguez³

et al. 2005

Mol Pharmacol

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Protein phosphatase types 1 (PP1) and 2A (PP2A) represent two major families of serine/threonine protein phosphatases that have been implicated in the regulation of many cellular processes, including cell growth and apoptosis in mammalian cells. PP1 and PP2A proteins are composed of oligomeric complexes comprising a catalytic structure (PP1c or PP2AC) containing the enzymatic activity and at least one more interacting subunit. The binding of different subunits to a catalytic structure generates a broad variety of holoenzymes. We showed here that casein kinase 2␣ (Ck2␣) and simian virus 40 small t antigen share a putative common ␤-strand structure required for PP2A1 trimeric holoenzyme binding. We have also characterized DPT-sh1, a short basic peptide from Ck2␣ that interacted only in vitro with the PP2A-A subunit and behaves as a nontoxic penetrating shuttle in several cultivated human cell lines and chick embryos. In addition, DPT-sh1 specifically accumulated in human red cells infected with Plasmodium falciparum malaria parasites. We therefore designed bipartite peptides containing DPT-sh1 and PP1-or PP2A-interacting sequences. We found that DPT-5, a DPT-sh1-derived peptide containing a short sequence identified in CD28 antigen, interacts with PP2A-B␣, and DPT-7, another DPT-sh1-derived peptide containing a short sequence identified in Bad as a PP1 catalytic consensus docking motif, induce apoptosis in cultivated cell lines. These results clearly indicate that the rational design of PP1/PP2A interacting peptides is a pertinent strategy to deregulate intracellular survival pathways.In eukaryotic cells, biological activity of nearly 30% of proteins is modulated by phosphorylation. Reversible protein phosphorylation regulates multiple cellular processes, including metabolism, signal transduction pathways, cell cycle progression, oncogenic transformation, cell differentiation, and apoptosis (Garcia et al., , 2003. Protein phosphorylation regulates the activities of protein kinases and protein phosphatases themselves (Hunter, 2000). Type 1 (PP1) and type 2A (PP2A) Ser/Thr protein phosphatases are major regulators of cell dephosphorylation. Binding of PP1 catalytic subunit (PP1c) to specific regulatory subunits generates a large family of PP1 holoenzymes (Cohen, 2002). For PP2AThis work was supported in part by the Institut-Pasteur (PTR-136 and DVPI 27147-27188) and by the Association pour la Recherche sur le Cancer grant 4437 (to A.G.) and grant 4812 (to S.A.S.). F.D. was supported by a fellowship grant from Institut-Pasteur (DVPI). J.G. is a recipient of a Ministere de la Recherche et Technologie fellowship from the French Government. V.J.Y. was supported by a Marie Curie IntraEuropean fellowship within the 6th European Community Framework Programme (contract MEIF-2003-501887

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“…The rabbit anti-Xenopus Aurora-A polyclonal antibody, the goat polyclonal antibody raised against Xenopus cyclin B2 and the guinea pig polyclonal antibodies directed against the 35 kDa catalytic subunit (C35) and the 65 kDa regulatory subunit (R65) of PP2A were described (Castro et al, 2002;De Smedt et al, 2000;Bosch et al, 1995) respectively. The mouse monoclonal antibody directed against the catalytic subunit of PP1 was purchased from Transduction Laboratories.…”

Section: Western Blottingmentioning

confidence: 99%

Differential regulation of Cdc2 and Aurora-A in Xenopus oocytes: a crucial role of phosphatase 2A

Maton

Lorca

Girault

et al. 2005

Journal of Cell Science

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The success of cell division relies on the activation of its master regulator Cdc2-cyclin B, and many other kinases controlling cellular organization, such as Aurora-A. Most of these kinase activities are regulated by phosphorylation. Despite numerous studies showing that okadaic acidsensitive phosphatases regulate both Cdc2 and Aurora-A activation, their identity has not yet been established in Xenopus oocytes and the importance of their regulation has not been evaluated. Using an oocyte cell-free system, we demonstrate that PP2A depletion is sufficient to lead to Cdc2 activation, whereas Aurora-A activation depends on Cdc2 activity. The activity level of PP1 does not affect Cdc2 kinase activation promoted by PP2A removal. PP1 inhibition is also not sufficient to lead to Aurora-A activation in the absence of active Cdc2. We therefore conclude that in Xenopus oocytes, PP2A is the key phosphatase that negatively regulates Cdc2 activation. Once this negative regulator is removed, endogenous kinases are able to turn on the activator Cdc2 system without any additional stimulation. In contrast, Aurora-A activation is indirectly controlled by Cdc2 activity independently of either PP2A or PP1. This strongly suggests that in Xenopus oocytes, Aurora-A activation is mainly controlled by the specific stimulation of kinases under the control of Cdc2 and not by downregulation of phosphatase.

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The PR55 and PR65 Subunits of Protein Phosphatase 2A from Xenopus laevis. Molecular Cloning and Developmental Regulation of Expression

Cited by 34 publications

References 66 publications

The phosphorylation of ARPP19 by Greatwall renders the autoamplification of MPF independent of PKA in Xenopus oocytes

The phosphorylation of ARPP19 by Greatwall renders the autoamplification of MPF independent of PKA in Xenopus oocytes

Use of Penetrating Peptides Interacting with PP1/PP2A Proteins As a General Approach for a Drug Phosphatase Technology

Differential regulation of Cdc2 and Aurora-A in Xenopus oocytes: a crucial role of phosphatase 2A

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