Premium
The Aspergillus nidulans sldI RAD50 gene interacts with bimE APC1 , a homologue of an anaphase‐promoting complex subunit
Author(s) -
Malavazi Iran,
Lima Joel Fernandes,
Fagundes Márcia Regina von Zeska Kress,
Efimov Vladimir P.,
Goldman Maria Helena de Souza,
Goldman Gustavo Henrique
Publication year - 2005
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2005.04671.x
Subject(s) - biology , aspergillus nidulans , rad50 , dna repair , complementation , dna damage , mutant , genetics , microbiology and biotechnology , dna replication , mutation , gene , dna , dna binding protein , transcription factor
Summary 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 sldI RAD50 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 mreA MRE11 inactivation strains were exposed to the DNA damage caused by bleomycin. Transformation experiments and Southern blot analysis indicate homologous recombination is dependent on scaA NBS1 function in the Mre11 complex. There are epistatic and synergistic interactions between sldI RAD50 and bimE APC1 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 .