Format

Send to

Choose Destination
DNA Repair (Amst). 2013 Sep;12(9):786-90. doi: 10.1016/j.dnarep.2013.05.003. Epub 2013 Jun 19.

The Shu complex regulates Rad52 localization during rDNA repair.

Author information

1
Columbia University Medical Center, Department of Genetics and Development, New York, NY 10032, United States.

Abstract

The Shu complex, consisting of Rad51 paralogues, is an important regulator of homologous recombination, an error-free DNA repair pathway. Consequently, when members of this complex are disrupted, cells exhibit a mutator phenotype, sensitivity to DNA damage reagents and increased gross chromosomal rearrangements. Previously, we found that the Shu complex plays an important role in ribosomal DNA (rDNA) recombination when the Upstream Activating Factor (UAF) protein Uaf30 is disrupted. UAF30 encodes a protein needed for rDNA transcription and when deleted, rDNA recombination increases and the rDNA expands in a Shu1-dependent manner. Here we find using the uaf30-sensitized background that the central DNA repair protein Rad52, which is normally excluded from the nucleolus, frequently overlaps with the rDNA. This close association of Rad52 with the rDNA is dependent upon Shu1 in a uaf30 mutant. Previously, it was shown that in the absence of Rad52 sumoylation, Rad52 foci mislocalize to the nucleolus. Interestingly, here we find that using the uaf30 sensitized background the ability to regulate Rad52 sumoylation is important for Shu1 dependent rDNA recombination as well as Rad52 close association with rDNA. Our results suggest that in the absence of UAF30, the Shu complex plays a central role in Rad52 rDNA localization as long as Rad52 can be sumoylated. This discrimination is important for rDNA copy number homeostasis.

KEYWORDS:

DNA repair; Rad52; Rad52 sumoylation; Shu complex; UAF complex; rDNA recombination

PMID:
23790361
PMCID:
PMC3811918
DOI:
10.1016/j.dnarep.2013.05.003
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center