WEE1+-LIKE GENE IN HUMAN-CELLS

THE wee1+ gene is a mitotic inhibitor controlling the G2 to M transition of the fission yeast Schizosaccharomyces pombe 1 and encodes a protein kinase with both serine- and tyrosine-phosphorylating activities 2. We have cloned a human gene (WEE1Hu) similar to wee1+ by transcomplementation of a yeast mutant 3,4. WEE1Hu encodes a protein homologous to the S. pombe wee1+ and mik1+ (a functionally redundant sibling of wee1+) 5 kinases and effectively rescues a wee1 mutation. We report here that overexpression of WEE1Hu in fission yeast generates very elongated cells as a result of inhibition of the G2-M transition in the cell cycle. In addition, we detected a 3-kilobase-long WEE1Hu messenger RNA in all the human cell lines we examined. We conclude that a wee1+-like gene exists and is expressed in human cells.