Interaction of non-histone proteins with DNA and chromatin from Drosophila and mouse cells. Specificity, isolation and analysis of complexes.
The specificity of the binding of purified non-histone proteins to DNA has been investigated through two types of experiments. Using a nitrocellulose filter assay at a low protein/DNA ratio, the binding of mouse non-histone proteins to mouse DNA was twice as great as the binding of mouse non histone protein to Drosophila DNA. The reverse experiment using Drosophila non-histone protein confirmed the interpretation that some protein . DNA complexes were specific. Protein . DNA complexes isolated by gel filtration chromatography indicated that 20% or 10% of the non-histone protein was bound to homologous or heterologous DNA respectively. Purified non-histone proteins bound with lower efficiency (15%) than unpurified but with higher specificity to soluble chromatin than to naked DNA. This binding did not result from an exchange between chromatin non-histone proteins and purified non-histone proteins added in excess. DNA-bound and chromatin-bound proteins were analysed on polyacrylamide gels. Whereas no major qualitative differences were observed with DNA-bound proteins, some proteins bound to homologous mouse chromatin were different from those bound to heterologous Drosophila chromatin. These results suggest a possible role of DNA-bound non-histone proteins in the regulation of gene expression.
D000818:Animals; D001345:Autoradiography; D002478:Cells, Cultured; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D004247:DNA; D004330:Drosophila; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D008321:Mammary Glands, Animal / Q000378:metabolism; D051379:Mice; D011485:Protein Binding; D013045:Species Specificity
D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D004247:DNA