Tissue-specific binding of total and .beta.-globin genomic DNA to nonhistone chromosomal proteins from mouse erythropoietic cells

Abstract

The synthesis and DNA binding activity of purified nuclear non-histone proteins from mouse erythroblasts and myoblasts were compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, affinity chromatography and protein blotting. The labeled non-histone proteins bound to mouse total DNA clearly differ between erythroid and muscle cell lines, but these differences mainly reflect the qualitative changes observed in their pattern of synthesis. By contrast, a cloned genomic mouse .beta.-globin DNA fragment binds specifically several proteins (100K [kilodalton], 65K, 50K, 45K and 34K) from erythropoietic Friend cells and does not bind any protein in the corresponding fraction from myoblasts. The specificity of these DNA protein interactions requires a NaCl concentration of 0.1 M and a low protein/DNA ratio. In these conditions .lambda. DNA binds the above proteins to only a small extent. During the dimethyl sulfoxide induced terminal differentiation of Friend mouse erythroleukemia (MEL) cells, there is an apparent overall decrease of total as well as globin DNA binding to the nuclear non-histone proteins but not to the histones, whereas no significant qualitative changes are detected.