IDENTIFICATION OF A XENOPUS CDNA THAT PREVENTS MITOTIC CATASTROPHE INTHE FISSION YEAST SCHIZOSACCHAROMYCES-POMBE

A Xenopus total ovary cDNA library was constructed in a fission yeast expression vector. Using a genetic functional complementation method, we have identified a Xenopus cDNA clone that can rescue several differ ent yeast mitotic catastrophe mutants defective in Wee1 kinase functio n at the restrictive temperature. The 3.0-kb cDNA clone contains an op en reading frame (ORF) of 2226 nucleotides, encoding a predicted 82-kD a protein. The deduced amino acid (aa) sequence shows seven almost ide ntical 30-aa tandem repeats, each of which contains a phosphorylation site meeting the consensus for both Cdc2 kinase and MAP kinase.