Ubiquitination plays an important role in the DNA damage response. We identified a novel interaction of the E3 ubiquitin ligase RNF8 with Nbs1, a key regulator of DNA double-strand break (DSB) repair. We found that Nbs1 is ubiquitinated both before and after DNA damage and is a direct ubiquitination substrate of RNF8. We also identified key residues on Nbs1 that are ubiquitinated by RNF8. By us...

Prabha Balaram1,*, Smriti M Krishna1, Susan James2, Vino. T. Cheriyan1, Sreelekha Therakathinal Thankappan1, Aleyamma Mathew3 Division of Cancer Research, Regional Cancer Centre, Medical College. P.O, Trivandrum 695 011, Kerala, India. Department of ENT, Medical College, Trivandrum 695-011, Kerala, India Department of Statistics, Regional Cancer Centre, Trivandrum, Kerala, India _______________...

A broken DNA molecule is difficult to repair, highly mutagenic, and extremely cytotoxic. Such breaks can be repaired by homology-independent or homology-directed mechanisms. Little is known about the network that controls the repair pathway choice except that a licensing step for homology-mediated repair exists, called DNA-end resection. The choice between these two repair pathways is a key eve...

The analysis of double-strand break (DSB) repair is complicated by the existence of several pathways utilizing a large number of genes. Moreover, many of these genes have been shown to have multiple roles in DSB repair. To address this complexity we used a repair reporter construct designed to measure multiple repair outcomes simultaneously. This approach provides estimates of the relative usag...

Experiments with the supF20 mutagenesis system demonstrate that extracts from Bloom's syndrome (BS) cells are unable to use microhomology elements within the supF20 gene to restore supF function after the induction of a double-strand break (DSB). Additional experiments with the pUC18 mutagenesis system demonstrate that although the efficiency and fidelity of DSB repair by BS extracts are compar...

What is the Rad52 protein? The Saccharomyces cerevisiae Rad52 protein is a key player in DNA doublestrand break repair and homologous recombination. It forms a heptameric ring, catalyses DNA annealing and mediates Rad51-catalysed strand invasion. RAD52 is the defining member of an epistasis group of genes involved in repair of ionizing radiationinduced DNA double-strand breaks. Double-strand br...

DNA double-strand breaks (DSBs) pose a serious threat to genomic integrity. If unrepaired, they can lead to chromosome fragmentation and cell death. If repaired incorrectly, they can cause mutations and chromosome rearrangements. DSBs are repaired using end-joining or homology-directed repair strategies, with the predominant form of homology-directed repair being synthesis-dependent strand anne...

The yields of unrepairable single-and double-strand breaks in the DNA of x-irradiated Chinese hamster cells were measured by low-speed neutral and alkaline sucrose density gradient sedimentation in order to investigate the relation between these lesions and reproductive death. After maximal single-strand remoining, at all doses, the number of residual single-strand breaks was twice the number o...