The Glc7 type 1 protein phosphatase of Saccharomyces cerevisiae is required for cell cycle progression in G2/M.
We isolated a mutant carrying a conditional mutation in the GLC7 gene, encoding the catalytic subunit of a type 1 protein phosphatase, by selection of suppressors that restored the growth defect of cdc24 mutants at high temperature and simultaneously conferred cold-sensitive growth. This cold sensitivity for growth is caused by a single mutation (glc7Y-170) at position 170 of the Glc7 protein, resulting in replacement of cysteine with tyrosine. Genetic analysis suggested that the glc7Y-170 allele is associated with a recessive negative phenotype, reducing the activity of Glc7 in the cell. The glc7Y-170 mutant missegregated chromosome III at the permissive temperature, arrested growth as large-budded cells at the restrictive temperature, exhibited a significant increase in the number of nuclei at or in the neck, and had a short spindle. Furthermore, the glc7Y-170 mutant exhibited a high level of CDC28-dependent protein kinase activity when incubated at the restrictive temperature. These findings suggest that the glc7Y-170 mutation is defective in the G2/M phase of the cell cycle. Thus, type 1 protein phosphatase in Saccharomyces cerevisiae is essential for the G2/M transition.
Hisamoto
N
N
Department of Molecular Biology, Faculty of Science, Nagoya University, Japan.
Sugimoto
K
K
Matsumoto
K
K
D000595:Amino Acid Sequence; D001483:Base Sequence; D017489:CDC28 Protein Kinase, S cerevisiae / Q000378:metabolism; D002453:Cell Cycle; D002874:Chromosome Mapping; D015825:Chromosomes, Fungal; D003001:Cloning, Molecular; D005656:Fungal Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D016195:G2 Phase; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D005838:Genotype; D006003:Glycogen / Q000378:metabolism; D008938:Mitosis; D008969:Molecular Sequence Data; D016296:Mutagenesis; D010641:Phenotype; D010749:Phosphoprotein Phosphatases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D010957:Plasmids; D011494:Protein Kinases / Q000378:metabolism; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D017386:Sequence Homology, Amino Acid
D005656:Fungal Proteins; D006003:Glycogen; D011494:Protein Kinases; D017489:CDC28 Protein Kinase, S cerevisiae; D010749:Phosphoprotein Phosphatases