Pharmacologic inhibitors of poly(ADP-ribose) polymerase (PARP) putatively enhance radiation toxicity in cancer cells. Although there is considerable information on the molecular interactions of PARP and BRCA1- and BRCA2-deficient cancers, very little is known of the PARP inhibition effect upon cancers proficient in DNA double-strand break repair after ionizing radiation or after stalled replica...

Ku is a heterodimeric protein with high binding affinity for ends, nicks, and gaps in double-stranded DNA. Both in mammalian cells and in budding yeast, Ku plays a role in nonhomologous end joining in the double strand break repair pathway. However, Ku has a more significant role in DNA repair in mammalian cells compared with yeast, in which a homology-dependent pathway is the predominant one. ...

We have determined the ability of two well-characterized eukaryotic homing endonucleases, I-PpoI from the myxomycete Physarum polycephalum and I-CreI from the green alga Chlamydomonas reinhardtii, to generate site-specific DNA double-strand breaks in human cells. These 18-kDa proteins cleave highly conserved 15- or 24-bp rDNA homing sites in their respective hosts to generate homogeneous 4-base...

Meets DNA Transcription and Recombination: When RNA Andrés Aguilera and Hélène Gaillard Mechanism and Regulation End Resection at Double-Strand Breaks: Lorraine S. Symington Resection in Homologous Recombination Structural Studies of DNA End Detection and Christian Linke-Winnebeck, et al. Christian Bernd Schiller, Florian Ulrich Seifert, The Dissolution of Double Holliday Junctions Anna H. Biza...

Unrepaired DNA double-strand breaks can lead to apoptosis or tumorigenesis. In mammals double-strand breaks are repaired mainly by nonhomologous end-joining mediated by the DNA-PK complex. The core protein of this complex, DNA-PKcs, is a DNA-dependent serine/threonine kinase that phosphorylates protein targets as well as itself. Although the (auto)phosphorylation activity has been shown to be e...

The repair of DNA double-strand breaks must be accurate to avoid genomic rearrangements that can lead to cell death and disease. This can be accomplished by promoting homologous recombination between correctly aligned sister chromosomes. Here, using a unique system for generating a site-specific DNA double-strand break in one copy of two replicating Escherichia coli sister chromosomes, we analy...

Inactivation of nuclear GSK3beta by Ser(389) phosphorylation promotes lymphocyte fitness during DNA double-strand break response" (2016). Davis Lab.

DNA double-strand breaks are particularly deleterious lesions that can lead to genomic instability and cell death. We investigated the SOS response to double-strand breaks in both Escherichia coli and Bacillus subtilis. In E. coli, double-strand breaks induced by ionizing radiation resulted in SOS induction in virtually every cell. E. coli strains incapable of SOS induction were sensitive to io...

Mating-type switching in the fission yeast Schizosaccharomyces pombe is initiated by a strand-specific imprint located at the mating-type (mat1) locus. We show that the imprint corresponds to a single-strand DNA break (SSB), which is site- but not sequence-specific. We identified three novel cis-acting elements, involved in the formation and stability of the SSB. One of these elements is essent...

Mdm2 is a critical negative regulator of the p53 tumor suppressor and is frequently overexpressed in human cancers. However, reports, including our own studies, suggest that Mdm2 has both p53-dependent and p53-independent functions that contribute to genomic instability and transformation when deregulated. We recently elucidated a p53-independent role for Mdm2 in the regulation of the DNA doubl...