It remains unknown whether the cell cycle system responds properly to protein synthesis inhibition. In this paper I report finding in Schizosaccharomyces pombe that partially deleted elongation factor 3 genes rescue various mitotic catastrophe mutants depending on Deltaste9 in a dominant-negative manner. in response to protein synthesis inhibitors, Deltaste9 and some other mutants delay halting the cell cycle at G2-M and the combined cdc2-M26 Deltaste9 mutant greatly loses viability. It is suggested that cell cycle be positively controlled in an ste9-dependent manner before essential factors for viability and other important functions are exhausted when protein synthesis is inhibited. (C) 2004 Elsevier Inc. All rights reserved.