Regulation of Wee1 kinase in response to protein synthesis inhibition

To investigate the mechanism coupling growth (protein synthesis) with cell division, we examined the relationship between the tyrosine kinase Wee1 tha t inhibits Cdc2-Cdc13 mitosis-inducing kinase by phosphorylating it, and pr otein synthesis inhibition in fission yeast. The wee1-50 mutant showed supe rsensitivity to protein synthesis inhibitor, cycloheximide, Wee1 was essent ial for the G(2) delay upon a partial inhibition of protein synthesis. Inde ed, the protein synthesis inhibition caused an increase in the Wee1 protein by the Sty1/Spc1 MAPK-dependent transcriptional and the Sty1/Spc1 MAPK-ind ependent post-transcriptional regulations. Further, the results indicated t hat the post-transcriptional regulation is important for the G(2) delay. (C ) 2000 Federation of European Biochemical Societies, Published by Elsevier Science B.V. All rights reserved.