title: HYS2, an essential gene required for DNA replication in Saccharomyces cerevisiae.
abstract: To investigate cell cycle regulation at the S or G2 phase in Saccharomyces cerevisiae, we have isolated mutants displaying supersensitivity to hydroxyurea (HU), a chemical that inhibits DNA replication. Such mutants, which we have named hydroxyurea sensitive (hys), defined four linkage groups and we characterized the hys2 mutation in this study. The hys2-1 mutant displays temperature sensitive growth and a constellation of phenotypes indicating defective DNA metabolism. At the restrictive temperature, hys2-1 cells arrest as large budded cells with a single nucleus at the neck of the bud and a short spindle. The hys2-1 mutant exhibits increased rates of chromosome loss and recombination. Additionally, hys2-1 appears to accumulate incompletely replicated DNA that can be detected by a pulse field electrophoresis assay. Finally, deletion of RAD9 in a hys2-1 strain decreases the percentage of arrested cells, suggesting that an intact RAD9-checkpoint is required for the cell cycle arrest in hys2-1 cells. HYS2 encodes a 55 kDa protein that is essential for viability at all temperatures. Taken together, these data suggest that Hys2 plays a role in DNA replication.
authors.affiliation: Department of Molecular Biology, Faculty of Science, Nagoya University, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Sugimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Sakamoto
authors.forename: O
authors.initials: O
authors.lastname: Takahashi
authors.forename: K
authors.initials: K
authors.lastname: Matsumoto
mesh_terms: D001483:Base Sequence; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000235:genetics*; D003001:Cloning, Molecular; D004258:DNA Polymerase III; D017931:DNA Primers / Q000737:chemistry; D004261:DNA Replication; D004271:DNA, Fungal / Q000096:biosynthesis; D004259:DNA-Directed DNA Polymerase; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D006918:Hydroxyurea / Q000494:pharmacology; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins
chemical_list: D018797:Cell Cycle Proteins; D017931:DNA Primers; D004271:DNA, Fungal; D004791:Enzyme Inhibitors; D005656:Fungal Proteins; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; D004258:DNA Polymerase III; D004259:DNA-Directed DNA Polymerase; C095943:POL31 protein, S cerevisiae; D006918:Hydroxyurea