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The akuB(KU80) mutant deficient for nonhomologous end joining is a powerful tool for analyzing pathogenicity in Aspergillus fumigatus.

ABSTRACT: To increase the frequency of homologous recombination, we inactivated the KU80 homologue in Aspergillus fumigatus (named akuB(KU80)). Homologous integration reached about 80% for both calcineurin A (calA) and polyketide synthase pksP (alb1) genes in the akuB(KU80) mutant to 3 and 5%, respectively, when using a wild-type A. fumigatus strain. Deletion of akuB(KU80) had no influence on pathogenicity in a low-dose murine infection model.

SUBMITTER: da Silva Ferreira ME

PROVIDER: S-EPMC1360264 | biostudies-literature | 2006 Jan

REPOSITORIES: biostudies-literature

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The akuB(KU80) mutant deficient for nonhomologous end joining is a powerful tool for analyzing pathogenicity in Aspergillus fumigatus.

da Silva Ferreira Márcia Eliana ME Kress Marcia R V Z MR Savoldi Marcela M Goldman Maria Helena S MH Härtl Albert A Heinekamp Thorsten T Brakhage Axel A AA Goldman Gustavo H GH

Eukaryotic cell 20060101 1

To increase the frequency of homologous recombination, we inactivated the KU80 homologue in Aspergillus fumigatus (named akuB(KU80)). Homologous integration reached about 80% for both calcineurin A (calA) and polyketide synthase pksP (alb1) genes in the akuB(KU80) mutant to 3 and 5%, respectively, when using a wild-type A. fumigatus strain. Deletion of akuB(KU80) had no influence on pathogenicity in a low-dose murine infection model. ...[more]

PMID: 16400184

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Gene targeting in Aspergillus fumigatus by homologous recombination is facilitated in a nonhomologous end- joining-deficient genetic background.

Project description:The akuA gene encoding the Ku70 component of the nonhomologous end-joining machinery was deleted in the opportunistic pathogen Aspergillus fumigatus. No obvious phenotype could be assessed for the corresponding mutant strain but relative frequencies of homologous recombination were increased as deduced from targeting the laccase-encoding abr2 gene.

| S-EPMC1360265 | biostudies-literature

Ubiquitylation of Ku80 by RNF126 Promotes Completion of Nonhomologous End Joining-Mediated DNA Repair.

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Project description:Poly(ADP-ribose) polymerase (PARP) inhibitors are strikingly toxic to cells with defects in homologous recombination (HR). The mechanistic basis for these findings is incompletely understood. Here, we show that PARP inhibitor treatment induces phosphorylation of DNA-dependent protein kinase substrates and stimulates error-prone nonhomologous end joining (NHEJ) selectively in HR-deficient cells. Notably, inhibiting DNA-dependent protein kinase activity reverses the genomic instability previously reported in these cells after PARP inhibition. Moreover, disabling NHEJ by using genetic or pharmacologic approaches rescues the lethality of PARP inhibition or down-regulation in cell lines lacking BRCA2, BRCA1, or ATM. Collectively, our results not only implicate PARP1 catalytic activity in the regulation of NHEJ in HR-deficient cells, but also indicate that deregulated NHEJ plays a major role in generating the genomic instability and cytotoxicity in HR-deficient cells treated with PARP inhibitors.

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