The 70 kD rat liver nucleoplasmic protein binding hormone responsive element of rat haptoglobin gene shares size, charge and epitopes with lamin A.

The 70 kD rat liver nucleoplasmic protein was shown previously to display binding affinity for hormone responsive element of rat haptoglobin gene which markedly increased during the acute-phase reaction. In this work the possibility of its structural homology to lamin-type intermediate filament proteins is assessed. The results of two-dimensional Southwestern and Western analyses pinpointed to size, charge and epitope homology between the 70 kD rat liver nucleoplasmic protein binding the hormone responsive element and the lamin A constituent of nuclear matrix structure.