p90Rsk is not involved in cytostatic factor arrest in mouse oocytes

Vertebrate oocytes arrest in metaphase of the second meiotic division (MII), where they maintain a high cdc2/cyclin B activity and a stable, bipolar spindle because of cytostatic factor (CSF) activity. The Mos–MAPK pathway is essential for establishing CSF. Indeed, oocytes from the mos−/− strain do not arrest in MII and activate without fertilization, as do Xenopus laevis oocytes injected with morpholino oligonucleotides directed against Mos. In Xenopus oocytes, p90Rsk (ribosomal S6 kinase), a MAPK substrate, is the main mediator of CSF activity. We show here that this is not the case in mouse oocytes. The injection of constitutively active mutant forms of Rsk1 and Rsk2 does not induce a cell cycle arrest in two-cell mouse embryos. Moreover, these two mutant forms do not restore MII arrest after their injection into mos−/− oocytes. Eventually, oocytes from the triple Rsk (1, 2, 3) knockout present a normal CSF arrest. We demonstrate that p90Rsk is not involved in the MII arrest of mouse oocytes.

[1]  C. Sette,et al.  Functional interaction between p90Rsk2 and Emi1 contributes to the metaphase arrest of mouse oocytes , 2004, The EMBO journal.

[2]  K. Okazaki,et al.  Parthenogenetic activation of oocytes in c-mos-deficient mice , 1994, Nature.

[3]  S. Geley,et al.  The spindle assembly checkpoint is not essential for CSF arrest of mouse oocytes , 2004, The Journal of cell biology.

[4]  W. Colledge,et al.  Activation of p90rsk during meiotic maturation and first mitosis in mouse oocytes and eggs: MAP kinase-independent and -dependent activation. , 1996, Development.

[5]  M. J. Richards,et al.  Disturbed Cholesterol Homeostasis in a Peroxisome-Deficient PEX2 Knockout Mouse Model , 2004, Molecular and Cellular Biology.

[6]  W. Colledge,et al.  Mos activates MAP kinase in mouse oocytes through two opposite pathways , 2000, The EMBO journal.

[7]  J. Rossant,et al.  Characterization of Mouse Rsk4 as an Inhibitor of Fibroblast Growth Factor-RAS-Extracellular Signal-Regulated Kinase Signaling , 2004, Molecular and Cellular Biology.

[8]  M. Evans,et al.  Mos is required for MAP kinase activation and is involved in microtubule organization during meiotic maturation in the mouse. , 1996, Development.

[9]  C. Carron,et al.  Frizzled receptor dimerization is sufficient to activate the Wnt/β-catenin pathway , 2003, Journal of Cell Science.

[10]  A. Hanauer,et al.  Expression analysis of RSK gene family members: the RSK2 gene, mutated in Coffin-Lowry syndrome, is prominently expressed in brain structures essential for cognitive function and learning. , 2002, Human molecular genetics.

[11]  J. Moreau,et al.  DOC1R: a MAP kinase substrate that control microtubule organization of metaphase II mouse oocytes , 2003, Development.

[12]  J. Ferrell,et al.  Cloning and Characterization of Xenopus Rsk2, the Predominant p90 Rsk Isozyme in Oocytes and Eggs* , 2000, The Journal of Biological Chemistry.

[13]  C. Jessus,et al.  Mos is not required for the initiation of meiotic maturation in Xenopus oocytes , 2002, The EMBO journal.

[14]  M. Schwab,et al.  Induction of metaphase arrest in cleaving Xenopus embryos by the protein kinase p90Rsk. , 1999, Science.

[15]  B. Tunquist,et al.  Spindle checkpoint proteins Mad1 and Mad2 are required for cytostatic factor–mediated metaphase arrest , 2003, The Journal of cell biology.

[16]  M. Schwab,et al.  The critical role of the MAP kinase pathway in meiosis II in Xenopus oocytes is mediated by p90Rsk , 2000, Current Biology.

[17]  M. Evans,et al.  Disruption of c-mos causes parthenogenetic development of unfertilized mouse eggs , 1994, Nature.

[18]  B. Maro,et al.  Meiotic spindle stability depends on MAPK-interacting and spindle-stabilizing protein (MISS), a new MAPK substrate , 2002, The Journal of cell biology.

[19]  J. Ferrell,et al.  The protein kinase p90 rsk as an essential mediator of cytostatic factor activity. , 1999, Science.

[20]  N. Winston,et al.  The metaphase II arrest in mouse oocytes is controlled through microtubule‐dependent destruction of cyclin B in the presence of CSF. , 1993, The EMBO journal.

[21]  G. V. Vande Woude,et al.  Cytoplasmic control of nuclear behavior during meiotic maturation of frog oocytes * , 1998, Biology of the cell.

[22]  S. Gammeltoft,et al.  Activation of p90Rsk1 Is Sufficient for Differentiation of PC12 Cells , 2004, Molecular and Cellular Biology.

[23]  J. Peters,et al.  The Meiosis I-to-Meiosis II Transition in Mouse Oocytes Requires Separase Activity , 2003, Current Biology.