title: Isolation of the Schizosaccharomyces pombe RAD54 homologue, rhp54+, a gene involved in the repair of radiation damage and replication fidelity.
abstract: The RAD54 gene of Saccharomyces cerevisiae encodes a putative helicase, which is involved in the recombinational repair of DNA damage. The RAD54 homologue of the fission yeast Schizosaccharomyces pombe, rhp54+, was isolated by using the RAD54 gene as a heterologous probe. The gene is predicted to encode a protein of 852 amino acids. The overall homology between the mutual proteins of the two species is 67% with 51% identical amino acids and 16% similar amino acids. A rhp54 deletion mutant is very sensitive to both ionizing radiation and UV. Fluorescence microscopy of the rhp54 mutant cells revealed that a large portion of the cells are elongated and occasionally contain aberrant nuclei. In addition, FACS analysis showed an increased DNA content in comparison with wild-type cells. Through a minichromosome-loss assay it was shown that the rhp54 deletion mutant has a very high level of chromosome loss. Furthermore, the rhp54 mutation in either a rad17 or a cdc2.3w mutant background (where the S-phase/mitosis checkpoint is absent) shows a significant reduction in viability. It is hypothesized that the rhp54+ gene is involved in the recombinational repair of UV and X-ray damage and plays a role in the processing of replication-specific lesions.
authors.affiliation: Department of Radiation Genetics and Chemical Mutagenesis, State University of Leiden, Netherlands.
authors.forename: D F
authors.initials: DF
authors.lastname: Muris
authors.forename: K
authors.initials: K
authors.lastname: Vreeken
authors.forename: A M
authors.initials: AM
authors.lastname: Carr
authors.forename: J M
authors.initials: JM
authors.lastname: Murray
authors.forename: C
authors.initials: C
authors.lastname: Smit
authors.forename: P H
authors.initials: PH
authors.lastname: Lohman
authors.forename: A
authors.initials: A
authors.lastname: Pastink
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004265:DNA Helicases / Q000235:genetics* / Q000378:metabolism; D004260:DNA Repair / Q000235:genetics*; D045643:DNA Repair Enzymes; D004271:DNA, Fungal / Q000235:genetics* / Q000528:radiation effects; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D017353:Gene Deletion; D005800:Genes, Fungal / Q000235:genetics; D008969:Molecular Sequence Data; D029701:Saccharomyces cerevisiae Proteins; D012568:Schizosaccharomyces / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid
chemical_list: D004271:DNA, Fungal; D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; C075468:RAD54 protein, S cerevisiae; D004265:DNA Helicases; C099034:Rhp54 protein, S pombe; D045643:DNA Repair Enzymes