Xenopus M phase MAP kinase: isolation of its cDNA and activation by MPF

EMBO J. 1991 Sep;10(9):2661-8.


MAP kinase is activated and phosphorylated during M phase of the Xenopus oocyte cell cycle, and induces the interphase-M phase transition of microtubule dynamics in vitro. We have carried out molecular cloning of Xenopus M phase MAP kinase and report its entire amino acid sequence. There is no marked change in the MAP kinase mRNA level during the cell cycle. Moreover, studies with an anti-MAP kinase antiserum indicate that MAP kinase activity may be regulated posttranslationally, most likely by phosphorylation. We show that MAP kinase can be activated by microinjection of MPF into immature oocytes or by adding MPF to cell-free extracts of interphase eggs. These results suggest that MAP kinase functions as an intermediate between MPF and the interphase-M phase transition of microtubule organization.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Blotting, Northern
  • Blotting, Western
  • Calcium-Calmodulin-Dependent Protein Kinases
  • Cloning, Molecular
  • DNA / genetics
  • Electrophoresis, Polyacrylamide Gel
  • Enzyme Activation
  • Maturation-Promoting Factor / pharmacology*
  • Mitosis
  • Molecular Sequence Data
  • Phosphorylation
  • Protein Kinase Inhibitors
  • Protein Kinases / genetics*
  • Protein Kinases / metabolism
  • Protein Processing, Post-Translational
  • RNA / analysis
  • Xenopus / genetics*


  • Protein Kinase Inhibitors
  • RNA
  • DNA
  • Protein Kinases
  • Calcium-Calmodulin-Dependent Protein Kinases
  • Maturation-Promoting Factor

Associated data

  • GENBANK/X59813