ISSN:
1365-2958
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
,
Medicine
Notes:
The Mre11–Rad50–Nbs1 protein complex has emerged as a central component in the human cellular DNA damage response, and recent observations suggest that these proteins are at least partially responsible for the linking of DNA damage detection to DNA repair and cell cycle checkpoint functions. We have identified Aspergillus nidulans sldI1444D mutant in a screen for dynein synthetic lethals. The sldIRAD50 gene was cloned by complementation of the sporulation deficiency phenotype of this mutant. A transversion G→C at the position 2509 (Ala-692-Pro amino acid change) in the sldI1444D mutant causes sensitivity to several DNA-damaging agents. The mutation sldI1 occurs at the CXXC hinge domain of Rad50. We have deleted part of the coiled-coil and few amino acids of the Rad50–Mre11 interaction region and assessed several phenotypic traits in this deletion strain. Besides sensitivity to a number of DNA-damaging agents, this deletion strain is also impaired in the DNA replication checkpoint response, and in ascospore viability. There is no delay of the S-phase when germlings of both sldI RAD50 and mreAMRE11 inactivation strains were exposed to the DNA damage caused by bleomycin. Transformation experiments and Southern blot analysis indicate homologous recombination is dependent on scaANBS1 function in the Mre11 complex. There are epistatic and synergistic interactions between sldI RAD50 and bimEAPC1 at S-phase checkpoints and response to hydroxyurea and UV light. Our results suggest a possible novel feature of the Mre11 complex in A. nidulans, i.e. a relationship with bimE APC1.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2958.2005.04671.x
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