Age-related changes in the activity and post-translational modification of DNA topoisomerase II in the quail oviduct]

In the present work, we show that the activity of DNA topoisomerase II in quail oviduct nuclei significantly increases with age. Posttranslational modifications of the nuclear-matrix-associated enzyme by matrix-bound poly(ADP-ribose) synthetase and protein kinase, whose activities change with age, are demonstrated and offer possible mechanisms by which the age-dependent change in enzyme activity may be caused. It is assumed that the age-correlated enhancement of DNA-topoisomerase-II activity may cause changes in the topological state of DNA, with possible consequences for DNA replication, transcription, and repair with age.