SELECTED NUCLEAR MATRIX PROTEINS ARE TARGETS FOR POLY(ADP-RIBOSE)-BINDING

Recent evidence suggests that poly(ADP-ribose) may take part in DNA st rand break signalling due to its ability to interact with and affect t he function of specific target proteins. Using a poly(ADP-ribose) blot assay we have found that several nuclear matrix proteins from human a nd murine cells bind ADP-ribose polymers with high affinity. The bindi ng was observed regardless of the procedure used to isolate nuclear ma trices, and it proved resistant to high salt concentrations. In murine lymphoma LY-cell cultures, the spontaneous appearance of radiosensiti ve LY-S sublines was associated with a loss of poly(ADP-ribose)-bindin g of several nuclear matrix proteins. Because of the importance of the nuclear matrix in DNA processing reactions, the targeting of matrix p roteins could be an important aspect of DNA damage signalling via the poly ADP-ribosylation system. J. Cell. Biochem. 70:596-603. (C) 1998 W iley-Liss, Inc.