X-ray survival characteristics and genetic analysis for nine saccharomyces deletion mutants that show altered radiation sensitivity
The availability of a genome-wide set of Saccharomyces deletion mutants provides a chance to identify all the yeast genes involved in DNA repair. Using X-rays, we are screening these mutants to identify additional genes that show increased sensitivity to the lethal effects of ionizing radiation. For each mutant identified as sensitive, we are confirming that the sensitivity phenotype co-segregates with the deletion allele and are obtaining multipoint survival-versus-dose assays in at least two haploid and one homozygous diploid strains. We present data for deletion mutants involving the genes DOT1, MDM20, NAT3, SPT7, SPT20, GCN5, HFI1, DCC1 and VID21/EAF1, and discuss their potential roles in repair. Eight of these genes have a clear radiation-sensitive phenotype when deleted, but the ninth, GCN5, has at most a borderline phenotype. None of the deletions confer substantial sensitivity to ultra-violet radiation, although one or two may confer marginal sensitivity. The DOT1 gene is of interest because its only known function is to methylate one lysine residue in the core of the histone H3 protein. We find that histone H3 mutants (supplied by K. Struhl) in which this residue is replaced by other amino-acids are also X-ray sensitive, seeming to confirm that methylation of the lysine-79 residue is required for effective repair of radiation damage.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE. Office of Management Budget and Evaluation; National Institutes of Health Grant GM5997901 (US)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 838070
- Report Number(s):
- LBNL-55624; R&D Project: L0154; TRN: US200507%%300
- Journal Information:
- Genetics, Vol. 169; Other Information: Submitted to Genetics: Volume 169; Journal Publication Date: January 2005; PBD: 7 Jan 2004
- Country of Publication:
- United States
- Language:
- English
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