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10:24

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Dependence of Mos-induced Cdc2 activation on MAP kinase function in a cell-free system

C Y Huang1, J E Ferrell

  • 1Department of Molecular Pharmacology, Stanford University School of Medicine, CA 94305-5332, USA.

The EMBO Journal
|May 1, 1996
PubMed

Insights

p42 MAP kinase activation is essential for Xenopus oocyte progression into meiotic M-phase. This study demonstrates that Cdc2 activation requires active p42 MAP kinase, highlighting its role in triggering M-phase.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Developmental Biology

Background:

  • Xenopus laevis oocytes arrest in G2 phase before meiotic M-phase.
  • Progression to M-phase involves simultaneous activation of p42 MAP kinase and Cdc2/cyclin B.
  • The precise regulatory relationship between these kinases is not fully understood.

Purpose of the Study:

  • To investigate whether Cdc2 activation is dependent on p42 MAP kinase function.
  • To elucidate the role of p42 MAP kinase in the M-phase trigger.

Main Methods:

  • Reconstitution of Mos-induced Cdc2 activation in cell-free Xenopus oocyte extracts.
  • Utilizing a MAP kinase phosphatase to assess inhibition.
  • Assessing the requirement for protein synthesis.

Main Results:

  • Mos-induced Cdc2 activation necessitates active p42 MAP kinase.
  • Inhibition of p42 MAP kinase activity by a specific phosphatase blocked Cdc2 activation.
  • Cdc2 activation occurred independently of new protein synthesis.

Conclusions:

  • p42 MAP kinase is a critical component in triggering M-phase entry in Xenopus oocytes.
  • This finding establishes a hierarchical relationship where p42 MAP kinase acts upstream of Cdc2/cyclin B for M-phase initiation.

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