Copper ion-mediated sensitization of nuclear matrix attachment sites to ionizing radiation.

Exposure of mammalian cells to ionizing radiation induces nuclear matrix proteins and their attached transcribing DNA sequences to form cross-links. To chracterize the cellular and matrix components necessary for DNA-protein crosslink (DPC) formation, DPC yields have been examined in isolated nuclear matrices and in the intermediate steps during cell fractionation. It was found that, in both unirradiated and irradiated cells, all components of DPC are retained in isolated nuclei, and the formed DPC are retained as well during the cell fractionation procedure resulting in nuclear matrices