MOLECULAR-CLONING AND CHARACTERIZATION OF A FISSION YEAST GENE RESPONSIBLE FOR SUPERSENSITIVITY TO THE SPINDLE POISON, ISOPROPYL N-3-CHLOROPHENYL CARBAMATE

The cps3 gene of the fission yeast, Schizosaccharomyces pombe, was pre viously identified as a mutation conferring supersensitivity to the sp indle poison, isopropyl N-3-chlorophenyl carbamate (CIPC). A 3.2 kb DN A fragment that complements the mutant phenotype was cloned from a S. pombe genomic library. The base sequence analysis showed that the frag ment contains a maximum 1086 nucleotide open reading frame and that th e putative product consists of 362 amino acids, having a molecular wei ght of 39.3 KDa. No significant homology of the potential product with known proteins could be found by database searches. A disruptant of t he gene, produced by insertion of a ura4(+) fragment was able to germi nate, but not to undergo cell division, suggesting that the gene to be essential for the cell cycle progression. The disruption experiment s uggests that the gene is an extragenic suppressor of cps3 mutation.