Genome Protection by DNA Polymerase θ

DNA polymerase theta (Pol theta) is a DNA repair enzyme widely conserved in animals and plants. Pol theta uses short DNA sequence homologies to initiate repair of double-strand breaks by theta-mediated end joining. The DNA polymerase domain of Pol theta is at the C terminus and is connected to an N-terminal DNA helicase-like domain by a central linker. Pol theta is crucial for maintenance of damaged genomes during development, protects DNA against extensive deletions, and limits loss of heterozygosity. The cost of using Pol theta for genome protection is that a few nucleotides are usually deleted or added at the repair site. Inactivation of Pol theta often enhances the sensitivity of cells to DNA strand-breaking chemicals and radiation. Since some homologous recombination-defective cancers depend on Pol theta for growth, inhibitors of Pol theta may be useful in treating such tumors.

Automated summary

DNA polymerase theta (Pol theta) is a DNA repair enzyme that plays a crucial role in maintaining genome integrity and protecting DNA against deletions and loss of heterozygosity. However, the use of Pol theta for genome protection may result in the deletion or addition of a few nucleotides at the repair site. Inactivation of Pol theta can enhance cell sensitivity to DNA strand-breaking chemicals and radiation, making inhibitors of Pol theta potentially useful in treating cancers dependent on homologous recombination.