Noncovalent Binding of Poly(ADP-Ribose) to Nuclear Matrix Proteins: Developmental Changes and Tissue Specificity

Abstract

AbstractPoly(ADP-ribose) is a nuclear polynucleotide involved in the regulation of chromatin functionsviacovalent and/or noncovalent modification of nuclear proteins. Using a binding assay on protein blots, we searched for poly(ADP-ribose) binding proteins in nuclear matrices from testes of differently aged rats as well as from various adult rat tissues (brain, liver, spleen). We found that nuclear matrix proteins represent a significant subset of the nuclear proteins that can establish noncovalent interactions with poly(ADP-ribose). The profiles of poly(ADP-ribose) binding nuclear matrix proteins appeared to be tissue-specific and changed during postnatal development in the testis.The isolation and analysis of endogenous poly (ADP-ribose) from rat testes showed that the ADP-ribose polymers that bind nuclear matrix proteinsin vitroare also present under physiologic conditionsin vivo. These results further substantiate the possibility that poly(ADP-ribose) may affect chromatin functions through noncovalent interaction with specific protein targets, including nuclear matrix components.