Interaction between cdc13+ and cdc2+ in the control of mitosis in fission yeast; dissociation of the G1 and G2 roles of the cdc2+ protein kinase.
A cold-sensitive (cs) allele of cdc2, a gene that acts in both the G1 and G2 phases of the fission yeast cell cycle, has been isolated by classical mutagenesis. Further mutagenesis of a cdc2cs strain yielded an extragenic suppressor that rescued the cs cell cycle defect but simultaneously conferred a temperature-sensitive (ts) cdc phenotype. This suppressor mutation was shown to be an allele of cdc13, a previously identified gene. A variety of allele-specific interactions between cdc2 and cdc13 were discovered. These included suppression of cdc13ts alleles by introduction of the cdc2+ gene on a multi-copy plasmid vector. cdc13+ is required in G2 for mitotic initiation and was shown to play no role in the G1 phase of the cell cycle. cdc2+, however, is essential in G1 for DNA replication and in G2 for mitosis. The newly isolated cs allele of cdc2 that is rescued by a ts allele of cdc13 is defective only in its G2 function. cdc13+ cooperates with cdc2+ in the initiation of mitosis but not in the regulation of DNA replication. We propose that the cdc13+ gene product might be a G2-specific substrate of the cdc2+ protein kinase.
Cold Spring Harbor Laboratory, NY 11724.
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D000483:Alleles; D002453:Cell Cycle; D003433:Crosses, Genetic; D005800:Genes, Fungal; D005838:Genotype; D010641:Phenotype; D011494:Protein Kinases / Q000235:genetics*; D004718:Saccharomycetales / Q000235:genetics*; D012568:Schizosaccharomyces / Q000166:cytology / Q000201:enzymology / Q000235:genetics*; D013489:Suppression, Genetic
D011494:Protein Kinases