POLQ suppresses interhomolog recombination and loss of heterozygosity at targeted DNA breaks
| Autor: | Kevin J Khoo, Luther Davis, Nancy Maizels, Yinbo Zhang |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Heterozygote
DNA End-Joining Repair DNA Ligases Somatic cell Loss of Heterozygosity DNA-Directed DNA Polymerase Compound heterozygosity Loss of heterozygosity chemistry.chemical_compound Genome editing Cell Line Tumor Homologous chromosome Humans DNA Breaks Double-Stranded DNA Breaks Single-Stranded Polymerase Recombination Genetic Multidisciplinary biology Recombinational DNA Repair Biological Sciences Cell biology chemistry Mutation biology.protein CRISPR-Cas Systems Recombination DNA |
| Zdroj: | Proc Natl Acad Sci U S A |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.2008073117 |
| Popis: | Interhomolog recombination (IHR) occurs spontaneously in somatic human cells at frequencies that are low but sufficient to ameliorate some genetic diseases caused by heterozygous mutations or autosomal dominant mutations. Here we demonstrate that DNA nicks or double-strand breaks (DSBs) targeted by CRISPR-Cas9 to both homologs can stimulate IHR and associated copy-neutral loss of heterozygosity (cnLOH) in human cells. The frequency of IHR is 10-fold lower at nicks than at DSBs, but cnLOH is evident in a greater fraction of recombinants. IHR at DSBs occurs predominantly via reciprocal end joining. At DSBs, depletion of POLQ caused a dramatic increase in IHR and in the fraction of recombinants exhibiting cnLOH, suggesting that POLQ promotes end joining in cis, which limits breaks available for recombination in trans. These results define conditions that may produce cnLOH as a mutagenic signature in cancer and may, conversely, promote therapeutic correction of both compound heterozygous and dominant negative mutations associated with genetic disease. |
| Databáze: | OpenAIRE |
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