Abstract
Following DNA damage or a block to DNA synthesis, checkpoint pathways act to arrest mitosis and prevent the attempted segregation of damaged or unreplicated DNA. The rad17 locus of Schizosaccharomyces pombe is one of seven known radiation-sensitive (rad) loci which are absolutely required to prevent mitosis following DNA damage in fission yeast. Six of these (rad1, rad3, rad9, rad17, rad26 and hus1) are also required for the checkpoint which prevents mitosis from occurring before DNA replication is complete. We report here that the predicted rad17 gene product is a basic hydrophilic protein of 606 amino acids which contains five domains with sequence homology to replication factor C (RF-C)/activator 1 subunits. Western analysis and fusion with Green Fluorescent Protein indicate that the abundance and electrophoretic mobility of Rad17 is not significantly modified following a block to DNA synthesis or following DNA damage, and that Rad17 is localized in the nucleus. Rad17 function is not essential for growth, but is required for the function of the DNA structure-dependent checkpoints. Site-directed mutagenesis has been used to demonstrate the biological significance of the RF-C/activator 1-related domains. These studies have also defined an element of the radiation sensitivity caused by loss of Rad17 function which is not associated with the radiation-induced G2 arrest defect seen in the rad17.d null mutant cells.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Base Sequence
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Cell Cycle Proteins*
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Cloning, Molecular
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DNA Damage
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DNA Repair / genetics
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DNA Replication / genetics
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DNA-Binding Proteins / chemistry
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Exodeoxyribonucleases / chemistry
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Exodeoxyribonucleases / genetics*
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Exodeoxyribonucleases / physiology
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Fungal Proteins / chemistry
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Fungal Proteins / genetics*
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Fungal Proteins / physiology
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Genes, Fungal
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Genetic Complementation Test
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Homeodomain Proteins*
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Hydroxyurea / pharmacology
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Intracellular Signaling Peptides and Proteins
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Microscopy, Fluorescence
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Minor Histocompatibility Antigens
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Mitosis / genetics
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Molecular Sequence Data
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Mutagenesis, Site-Directed / genetics
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Nuclear Proteins
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Proto-Oncogene Proteins c-bcl-2*
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Replication Protein C
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Repressor Proteins*
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S Phase / genetics
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Saccharomyces cerevisiae / genetics
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Saccharomyces cerevisiae Proteins*
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Schizosaccharomyces / chemistry*
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Schizosaccharomyces / genetics*
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Schizosaccharomyces pombe Proteins
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Sequence Analysis
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Sequence Homology, Nucleic Acid
Substances
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BCL2-related protein A1
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Cell Cycle Proteins
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DNA-Binding Proteins
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Fungal Proteins
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Homeodomain Proteins
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Intracellular Signaling Peptides and Proteins
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MATA1 protein, S cerevisiae
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Minor Histocompatibility Antigens
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Nuclear Proteins
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Proto-Oncogene Proteins c-bcl-2
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RAD17 protein, S cerevisiae
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RAD24 protein, S cerevisiae
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Repressor Proteins
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Saccharomyces cerevisiae Proteins
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Schizosaccharomyces pombe Proteins
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rad24 protein, S pombe
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Exodeoxyribonucleases
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Replication Protein C
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Hydroxyurea